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Leg Muscle Mass and Composition in Relation to Lower Extremity Performance in Men and Women Aged 70 to 79: The Health, Aging and Body Composition Study
Abstract
The loss of muscle mass with aging, or sarcopenia, is hypothesized to be associated with the deterioration of physical function. Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP).
A cross-sectional study, using baseline data of the Health, Aging and Body Composition study (1997/98).
Medicare beneficiaries residing in ZIP codes from the metropolitan areas surrounding Pittsburgh, Pennsylvania, and Memphis, Tennessee.
Three thousand seventy-five well-functioning black and white men and women aged 70 to 79.
Two timed tests (6-meter walk and repeated chair stands) were used to measure LEP. Muscle cross-sectional area and muscle tissue attenuation (indicative of fat infiltration) were obtained from computed tomography scans at the midthigh. Body fat was assessed using dual-energy x-ray absorptiometry.
Blacks had greater muscle mass and poorer LEP than whites. Black women had greater fat infiltration into the muscle than white women. After adjustment for clinic site, age, height, and total body fat, smaller muscle area was associated with poorer LEP in all four race-gender groups. (Regression coefficients, expressed per standard deviation (+/-55 cm2) of muscle area, were 0.658 and 0.519 in white and black men and 0.547 and 0.435 in white and black women, respectively, P <.01.) In addition, reduced muscle attenuation-indicative of greater fat infiltration into the muscle-was associated with poorer LEP, independent of total body fat and muscle area. (Regression coefficients per standard deviation (= 7 Hounsfield Units) of muscle attenuation were 0.292 and 0.224 in white and black men, and 0.193 and 0.159 in white and black women, respectively, P <.05). The most important body composition components related to LEP were muscle area in men and total body fat in women. Results were similar after additional adjustment for lifestyle factors and health status. No interactions between race and muscle area (P>.7) or between race and muscle attenuation (P>.2) were observed.
Smaller midthigh muscle area and greater fat infiltration in the muscle are associated with poorer LEP in well-functioning older men and women.
... Furthermore, low appendicular muscle mass [11,12] may also be a factor for decreasing OLST; however, no studies have investigated the possible involvement of directly measured muscle quality (i.e., amount of fat deposition in the skeletal muscle) in OLST. In contrast, excessive fat deposition in the muscle has been associated with other physical performance measures, including weak handgrip strength [13] and knee extension strength [14], slow gait speeds [13,15], prolonged chair standing time [15], and faster gait speed decline [16]. If OLST was associated not only with muscle mass but also with fat deposition in the muscle similar to another physical performance measure, these results support to use OLST as a simple measure of physical performance. ...
... Furthermore, low appendicular muscle mass [11,12] may also be a factor for decreasing OLST; however, no studies have investigated the possible involvement of directly measured muscle quality (i.e., amount of fat deposition in the skeletal muscle) in OLST. In contrast, excessive fat deposition in the muscle has been associated with other physical performance measures, including weak handgrip strength [13] and knee extension strength [14], slow gait speeds [13,15], prolonged chair standing time [15], and faster gait speed decline [16]. If OLST was associated not only with muscle mass but also with fat deposition in the muscle similar to another physical performance measure, these results support to use OLST as a simple measure of physical performance. ...
... Previous studies reported muscle mass decline and intramuscular fat deposition associated with physical performance measures of lower extremities, such as knee extension strength [14], gait speeds [13,15,16], and prolonged chair standing time [15]. Although shorting OLST has been thought to occur due to muscle weakness or impairment of sensory, motor, and central processing systems, our results suggested the importance of recognizing OLST as a manifestation of poor muscle quality. ...
Backgrounds
One-leg standing time (OLST) has been frequently used physical performance measure; however, what muscular characteristics OLST represents remains uncertain.
Aim
This cross-sectional study aimed to investigate the association between OLST and muscle characteristics to clarify the possibility of using OLST as a physical performance measure.
Methods
Study participants comprised 1144 older adults aged 65 years or older. Computed tomography images provided mid-thigh skeletal muscle cross-sectional area and mean attenuation value. OLST was measured for a maximum of 60 s. Static postural instability was assessed using a posturography.
Results
A frequency of OLST < 20 s was increased by quartiles of muscle cross-sectional area (Q1: 33.6, Q2: 12.8, Q3: 13.6, Q4: 11.9%, P < 0.001) and mean attenuation value (Q1: 32.3, Q2: 21.7, Q3: 14.3, Q4: 7.7%, P < 0.001). Results of the multinomial regression analysis indicated that muscle cross-sectional area and mean attenuation value were independently associated with an OLST of less than 20 s. The crude odds ratio of OLST less than 20 s for the lowest quartiles of both cross-sectional area and mean attenuation value was 4.19 (95% CI: 3.01 − 5.84). The cross-sectional area of muscles with greater fat deposition was inversely associated with OLST, while that with smaller fat deposition showed a positive association with OLST, indicating why mean attenuation value and cross-sectional area were independently associated with OLST. No clear relationship was observed with static postural instability.
Conclusion
OLST was a simply measurable quantifiable physical measure representing the loss of muscle mass and quality in older adults.
... For older adults, it is well-documented that fat mass of the total body is inversely associated with lower extremity performance, as demonstrated by items such as the scores of repeated chair-stand and 6-m walk [12][13][14][15][16]. Cross-sectional studies have suggested that deleterious effects on lower extremity performance with increases in fat mass would be greater than those occurring alongside decreases in fatfree mass [12,[17][18][19][20]. ...
... For example, Bouchard et al. (2009) reported that relative to sarcopenia, obesity per se contributed to lower global physical capacity. In addition, the negative in uence of increased fat mass has been shown to be greater in women than in men [15,21]. [17] found that fat mass, more than muscle strength, was the major determinant of physical function and disability in postmenopausal women. ...
... In addition, CSAs of the three muscle groups were also not signi cantly correlated with scores of the three performance tests except for the relationship between QF CSA and Two-step length. These results are consistent with previous ndings of cross-sectional studies [12,15,17,21] and suggest that the magnitude of FM is more in uential than LSTM with regard to lower extremity performance in older women. However, results of the multiple regression analysis (Table 3) deny the aforementioned consideration based on the absolute values of the measured parameters. ...
Background: This study aimed to elucidate whether total body composition or thigh muscularity is more closely associated with lower extremity performance in older women.
Methods: Sixty-seven Japanese women aged 60-77 years voluntarily participated in this study. Fat mass (FM) and lean soft tissue mass (LSTM) of each body segment and total body were determined using a dual-energy X-ray absorptiometry scanner and expressed as values relative to body mass (FM/BM and LSTM/BM, respectively). In addition, cross-sectional area (CSA) was determined for each of the quadriceps femoris (QF), hamstrings (HAM), and adductors at mid-thigh using magnetic resonance imaging and expressed as the value relative to the two-third power of body mass (CSA/BM2/3). Participants conducted three performance tests: 5-m walking at normal speed, Timed Up and Go (TUG), and Two-step.
Results: FM and FM/BM of the legs and total body were significantly correlated with scores of the three tests, and LSTM/BM of the legs and total body with 5-m walking time and Two-step length. QF CSA/BM2/3 was correlated with scores of the three tests, and HAM CSA/BM2/3 with Two-step length and TUG time. Multiple regression analyses identified LSTM/BM of the legs as an explanatory factor for 5-m walking time, waist circumference and QF CSA/BM2/3 for Two-step length, and age and QF CSA/BM2/3 for TUG time.
Conclusion: In older women, compared to total body composition, LSTM of the legs and CSA of the QF, expressed as values relative to body mass, are more closely associated with lower extremity performance.
Trial registration number: UMIN000024651 (2016.10.31.)
... It has been reported that postmenopausal hormonal changes in women inevitably result in increased body fat and reduced muscle mass [30], and obesity in women can amplify sarcopenia [31]. Obesity and low muscle mass in elderly individuals can hasten the onset of geriatric syndromes, contributing to fall accidents and worsening the quality of life for elderly individuals with weakened immunity and resilience. ...
... It has been reported that sarcopenia can diminish physical fitness and exercise capacity [31]. In this study, we conducted an analysis of health-related physical fitness, including maximal strength, muscular endurance, power, balance, and coordination. ...
Normal weight obesity (NWO) refers to a condition in which the body mass index falls within the normal range, but the percent of body fat is excessive. Although there are reports of a high prevalence of cardiovascular and metabolic diseases in NWO, analyses regarding physical fitness have been lacking. Therefore, the purpose of this study was to analyze the age-related prevalence of NWO and to examine physical fitness across generations. Our study utilized a dataset comprising 119,835 participants for analysis. The prevalence of NWO across ages was examined using cross-tabulation analysis. For body composition and physical fitness, medians and group differences were assessed by generation through Kruskal–Wallis and Bonferroni post hoc tests. Additionally, univariate logistic regression was adopted to analyze the odds ratio. The prevalence of NWO in Korean women was 18.3%. The fat-free mass of the NWO group was consistently lower than that of both the group with normal body mass indexes (Normal) and obese body mass indexes (Obesity) across all generations. Additionally, the waist circumference and blood pressure were greater in the now group than in the Normal group. When considering maximal strength, muscle endurance, power, balance, and coordination, the NWO group exhibited lower levels compared to the Normal group. The NWO group showed lower muscle mass than both the Normal and Obesity groups, resulting in significantly reduced physical fitness compared to that of the Normal group, similar to the Obesity group. This condition may increase not only the risk of posing a potentially more serious health concern than obesity but also the risk of falls in elderly people. Therefore, based on this study, it is crucial to not only define obesity using BMI criteria but also to diagnose NWO. Public health policies and preventive measures must be implemented accordingly.
... These two parameters can be determined with MRI muscle measurements. Increased FI and reduced fCSA are taken as surrogate markers for degraded, weaker muscle [10]. The literature highlights that FI is probably the more important parameter in determining muscle functional status. ...
... In the absence of the paraspinal muscles, the spine would be highly unstable even under minimal loads [5] It is known that with increasing age, but also with spinal pathologies, the PPM degenerates. Radiologically, this can be measured using surrogate markers such as fCSA and FI where a higher FI implies weaker muscle [10,11,26] However, definitive cut off values for the paraspinal muscles have not been established to date to understand when FI is considered pathological. ...
Background
The function of the paraspinal muscles and especially the psoas muscle in maintaining an upright posture is not fully understood. While usually considered solely as a hip flexor, the psoas muscle and its complex anatomy suggest that the muscle has other functions involved in stabilizing the lumbar spine. The aim of this study is to determine how the psoas muscle and the posterior paraspinal muscles (PPM; erector spinae and multifidus ) interact with each other.
Methods
A retrospective review including patients undergoing posterior lumbar fusion surgery between 2014 and 2021 at a tertiary care center was conducted. Patients with a preoperative lumbar magnetic resonance imaging (MRI) scan performed within 12 months prior to surgery were considered eligible. Exclusion criteria included previous spinal surgery at any level, lumbar scoliosis with a Cobb Angle > 20° and patients with incompatible MRIs. MRI-based quantitative assessments of the cross-sectional area (CSA), the functional cross-sectional area (fCSA) and the fat area (FAT) at L4 was conducted. The degree of fat infiltration (FI) was further calculated. FI thresholds for FI PPM were defined according to literature and patients were divided into two groups (< or ≥ 50% FI PPM ).
Results
One hundred ninetypatients (57.9% female) with a median age of 64.7 years and median BMI of 28.3 kg/m ² met the inclusion criteria and were analyzed. Patients with a FI PPM ≥ 50% had a significantly lower FI in the psoas muscle in both sexes. Furthermore, a significant inverse correlation was evident between FI PPM and FI Psoas for both sexes. A significant positive correlation between FAT PPM and fCSA Psoas was also found for both sexes. No significant differences were found for both sexes in both FI PPM groups.
Conclusion
As the FI PPM increases, the FI Psoas decreases. Increased FI is a surrogate marker for a decrease in muscular strength. Since the psoas and the PPM both segmentally stabilize the lumbar spine, these results may be indicative of a potential compensatory mechanism. Due to the weakened PPM, the psoas may compensate for a loss in strength in order to stabilize the spine segmentally.
... On the other hand, different studies show how muscle mass is intimately linked to the thigh circumference, which is more easily and quickly affected by hypo or inactivity conditions [27,28]. Similarly, a muscle loss of the lower limbs area (thigh and calf) is usually an index of a poor overall muscular performance [29,30]. ...
... These findings can be interpreted with some semi-quantitative deductions: intuitively, it is clear that the lack of physical activity or a general poor health condition that result in a loss of muscle mass might cause a decrease of the circumference of some corporal segments, and, in particular, the most prominent ones (i.e. the lower limb). This fact, which is largely supported by the state-of-the-art literature [27][28][29][30], is in full agreement with the suggestions of our data-driven approach. ...
Background:
Sarcopenia is a risk factor for morbidity and preventable mortality in old age, with consequent high costs for the national health system. Its diagnosis requires costly radiological examinations, such as the DEXA, which complicate screening in medical centers with a high prevalence of sarcopenia.
Objectives:
Developing a nearly zero-cost screening tool to emulate the performance of DEXA in identifying patients with muscle mass loss. This can crucially help the early diagnosis of sarcopenia at large-scale, contributing to reduce its prevalence and related complications with timely treatments.
Methods:
We exploit cross-sectional data for about 14,500 patients and 38 non-laboratory variables from successive NHANES over 7 years (1999-2006). Data are analyzed through a state-of-the-art artificial intelligence approach based on decision trees.
Results:
A reduced number of anthropometric parameters allows to predict the outcome of DEXA with AUC between 0.92 and 0.94. The most complex model derived in this paper exploits 6 variables, related to the circumference of key corporal segments and to the evaluation of body fat. It achieves an optimal trade-off sensitivity of 0.89 and a specificity of 0.82. Restricting exclusively to variables related to lower limb, we obtain an even simpler tool with only slightly lower accuracy (AUC 0.88-0.90).
Conclusions:
Anthropometric data seem to contain the entire informative content of a more complex set of non-laboratory variables, including anamnestic and/or morbidity factors. Compared to previously published screening tools for muscle mass loss, the newly developed models are less complex and achieve a better accuracy. The new results might suggest a possible inversion of the standard diagnostic algorithm of sarcopenia. We conjecture a new diagnostic scheme, which requires a dedicated clinical validation that goes beyond the scope of the present study.
... Cross-sectional area (CSA, cm 2 ) and attenuation of the mid-thigh muscles were measured by CT ( (Goodpaster et al., 2001;Visser, Kritchevsky, et al., 2002;Visser, Pahor, et al., 2002). An anteriorposterior scout scan of the entire femur was used to localize the mid-thigh. ...
... There were differences (p < 0.05) between men and women, and White and Black participants for quadriceps (men: 124.1 ± 0.7, women: 84.3 ± 0.9; White: 98.3 ± 0.7, Black: 110.1 ± 1.0 cm 2 ) and hamstrings (men: 63.3 ± 0.4, women: 46.1 ± 0.6; White: 50.4 ± 0.4, Black 59.1 ± 0.6 cm 2 ) skeletal muscle size, as has been previously shown in the larger Health ABC cohort (Goodpaster et al., 2001;Newman et al., 2003;Schaap et al., 2009;Taaffe et al., 2001;Visser, Kritchevsky, et al., 2002;Visser, Pahor, et al., 2002). Quadriceps and hamstrings skeletal muscle F I G U R E 1 Participant exclusions and propensity score matching used to produce the final cohort used in the current investigation. ...
Aspirin is one of the most commonly consumed cyclooxygenase (COX)-inhibitors and anti-inflammatory drugs and has been shown to block COX-produced regulators of inflammation and aging skeletal muscle size. We used propensity score matching to compare skeletal muscle characteristics of individuals from the Health ABC study that did not consume aspirin or any other COX-inhibiting drugs (non-consumers, n = 497, 74 ± 3 year, 168 ± 9 cm, 75.1 ± 13.8 kg, 33.1 ± 7.4% body fat, 37% women, 34% black) to those that consumed aspirin daily (and not any other COX-inhibiting drugs) and for at least 1 year (aspirin consumers, n = 515, 74 ± 3 year, 168 ± 9 cm, 76.2 ± 13.6 kg, 33.8 ± 7.1% body fat, 39% women, 30% black, average aspirin consumption: 6 year). Subjects were matched (p > 0.05) based on age, height, weight, % body fat, sex, and race (propensity scores: 0.33 ± 0.09 vs. 0.33 ± 0.09, p > 0.05). There was no difference between non-consumers and aspirin consumers for computed tomography-determined muscle size of the quadriceps (103.5 ± 0.9 vs. 104.9 ± 0.8 cm2 , p > 0.05) or hamstrings (54.6 ± 0.5 vs. 54.9 ± 0.5 cm2 , p > 0.05), or quadriceps muscle strength (111.1 ± 2.0 vs. 111.7 ± 2.0 Nm, p > 0.05). However, muscle attenuation (i.e., density) was higher in the aspirin consumers in the quadriceps (40.9 ± 0.3 vs. 44.4 ± 0.3 Hounsfield unit [HU], p < 0.05) and hamstrings (27.7 ± 0.4 vs. 33.2 ± 0.4 HU, p < 0.05). These cross sectional data suggest that chronic aspirin consumption does not influence age-related skeletal muscle atrophy, but does influence skeletal muscle composition in septuagenarians. Prospective longitudinal investigations remain necessary to better understand the influence of chronic COX regulation on aging skeletal muscle health.
... [7] Excess IMAT is associated with lower levels of muscle strength, impaired mobility, older age and higher risk of disability. [3,[7][8][9][10][11][12] It is acknowledged that adipose tissues not only serve as energy storage but also have a direct mechanical function, providing protection for sensitive organs and buffering body parts exposed to high levels of mechanical stress. [13,14] Kager's fat pad is an example of a deep-seated fat pad, i.e. ...
Objectives: To describe the morphological characteristics of subfascial intermuscular adipose tissue (IMATS) in the anterior compartment of the leg, considering its developmental and functional relationship with the crural fascia. Methods: In twenty formalin-fixed cadaveric legs (13 males, 7 females), after removal of the skin and crural fascia, the IMATS was exposed and classified into four types according to its shape. Leg length was divided into eight regions. The length, width at the widest point, closest distances of the upper and lower ends to the intermalleolar line and the anterior margin of the tibia, as well as the thickness of the skin-subcutaneous tissue complex, limb and leg lengths were measured for IMATS. Results: The most common type of IMATS was the short-large type. The largest point of IMATS was located in zone 3 or 4, and this point was located in the two zones closest to the lower end of IMATS in 75% of cases. In all cases, one to three connecting vessels piercing the crural fascia (80% were in zones 2, 3 or 4) connected to the IMATS in a slightly lateral to medial oblique course of the IMATS from top to bottom. The IMATS was superficially located in the tendinous and muscular parts of the extensor digitorum longus and/or tibialis anterior muscles, loosely attached to the muscles and crural fascia, but not between the muscle fibers. Although the largest point (p=0.041) and the distance from the distal end to the anterior margin of the tibia were found to be greater in males (p=0.049), the gender difference disappeared when normalized for limb length. Conclusion: No data on IMATS morphometry could be found in the literature. A remarkable finding of the study, which is open to interpretation in terms of the function of the IMATS, is that the location of the IMATS overlaps with the crural fascia region, which is reported to be biomechanically stiffer in the transverse direction. Our data that a connecting vessel is always connected to the IMATS by a fixed spatial relationship strengthens the argument that the developmental history of both structures may intersect.
... Large epidemiologic studies have described an association between | 5 of 11 DONDERO et al. IMAT, current mobility deficits, and increased risk for future loss of mobility (Addison, Marcus, et al., 2014;Marcus et al., 2012;Visser et al., 2005;Visser, Kritchevsky, et al., 2002). This is especially true with its presence in the muscles of posture and locomotion, particularly the hip abductors. ...
Myosteatosis, or the infiltration of fatty deposits into skeletal muscle, occurs with advancing age and contributes to the health and functional decline of older adults. Myosteatosis and its inflammatory milieu play a larger role in adipose tissue dysfunction, muscle tissue dysfunction, and increased passive muscle stiffness. Combined with the age‐related decline of sex hormones and development of anabolic resistance, myosteatosis also contributes to insulin resistance, impaired muscle mechanics, loss of force production from the muscle, and increased risk of chronic disease. Due to its highly inflammatory secretome and the downstream negative effects on muscle metabolism and mechanics, myosteatosis has become an area of interest for aging researchers and clinicians. Thus far, myosteatosis treatments have had limited success, as many lack the potency to completely rescue the metabolic and physical consequences of myosteatosis. Future research is encouraged for the development of reliable assessment methods for myosteatosis, as well as the continued exploration of pharmacological, nutritional, and exercise‐related interventions that may lead to the success in attenuating myosteatosis and its clinical consequences within the aging population.
... Numerous prior researches have demonstrated that QCT examination is a reliable tool for determining the human body's composition [15,16]. Intermuscular adipose tissue (IMAT) has been associated with lower muscle strength, power, and quality, chronic inflammation as well as impaired glucose tolerance in old adults [17][18][19]. ...
Background
Fatigue is a relatively prevalent condition among hemodialysis patients, resulting in diminished health-related quality of life and decreased survival rates. The purpose of this study was to investigate the relationship between fatigue and body composition in hemodialysis patients.
Methods
This cross-sectional study included 92 patients in total. Fatigue was measured by Functional Assessment of Chronic Illness Therapy – Fatigue (FACIT-F) (cut-off ≤ 34). Body composition was measured based on quantitative computed tomography (QCT), parameters including skeletal muscle index (SMI), intermuscular adipose tissue (IMAT), and bone mineral density (BMD). Handgrip strength was also collected. To explore the relationship between fatigue and body composition parameters, we conducted correlation analyses and binary logistic regression.
Results
The prevalence of fatigue was 37% (n = 34), abnormal bone density was 43.4% (n = 40). There was a positive correlation between handgrip strength and FACIT-F score (r = 0.448, p < 0.001). Age (r = − 0.411, p < 0.001), IMAT % (r = − 0.424, p < 0.001), negatively associated with FACIT-F score. Multivariate logistic regression analysis shows that older age, lower serum phosphorus, higher IMAT% are associated with a high risk of fatigue.
Conclusion
The significantly increased incidence and degree of fatigue in hemodialysis patients is associated with more intermuscular adipose tissue in paraspinal muscle.
... Meanwhile, older women engage in far less physical activity than men in the same age group, and older women have higher body fat and relatively lower muscle strength than men [15]. When elderly women become obese, even a small decrease in muscle strength can lead to difficulties with mobility or weight-bearing, and the resulting consequences become strength can lead to difficulties with mobility or weight-bearing, and the resulting consequences become more serious [16]. ...
Abdominal obesity (AO) and dynapenia (DP) are associated with cognitive decline, and the relationship between dynapenic abdominal obesity (DAO), a combination of DP and AO, and mild cognitive impairment (MCI) has been confirmed. This study aims to determine whether this relationship exhibits potential sex differences. The relationship between MCI and DAO was confirmed in 1309 community elderly individuals aged 65 years or older who were not diagnosed with dementia. The MCI was defined as a Korean mini-mental state examination (K-MMSE) score of 18–23 points. Multiple logistic regression analyses were conducted, categorizing participants into groups: a control group without AO or DP, an AO group, a DP group, and a DAO group. The study results showed that in women, both DP and DAO were significantly associated with MCI not only in the unadjusted Model 1 but also in Model 2, which adjusted for general characteristics and health behaviors, and Model 3, which additionally adjusted for chronic diseases and disease-related characteristics. In men, DP was associated with MCI in the unadjusted Model 1. The findings highlight sex differences in the impact of the DAO on MCI. These differences should be considered when studying the factors related to MCI in old age.
... On the other hand, anterior thigh muscle measurements show higher correlations with muscle performance tests. 4,6 Moreover, anterior thigh measurement is shown as an indicator of physical activity and mobility, 2 although no relationship was found between these parameters and TMT in this study. Accordingly, the anterior thigh muscle measurement, instead of TMT, will better reveal the lower extremity function. ...
... The skeletal muscle is an active endocrine tissue that serves as a source of protein, with key influences on glucose and energy metabolism, and a major role in mobility (1,2). Muscle mass progressively declines with age, and numerous studies have observed that this scenario is of public health concern, given its independent associations with negative outcomes, including diminished physical performance, mobility loss, osteoarthritis, dementia, and death (3)(4)(5)(6). ...
Background
The present study aimed to provide age- and sex-specific normative values for muscle mass parameters in Brazilian adults.
Methods
Data pertaining to Brazilian adults (18+ years) who attended a nutritional clinical between January 2018 and July 2022 were analyzed. Muscle mass parameters were assessed using a bioimpedance digital scale (InBody 230, GBC BioMed NZ). Assessments were conducted under standard conditions, with participants refraining from physical exercise for 96 h and from eating or drinking (including water) for 8 h before evaluations.
Results
A total of 18,625 Brazilian adults were analyzed. Normative values for absolute and relative (height, m²) muscle mass and appendicular muscle mass (ASM) were calculated. In addition, specific age-related changes in muscle mass parameters were observed. In women, muscle mass peaked between the ages of 40–49 before gradually declining at an average rate of 5.7% per decade from the sixth decade of life onwards. ASM reached its peak earlier, during the third decade of life, and started to decline later, from 50 to 59 years. In contrast, absolute and ASM peaked at 40–49 years and declined from the sixth decade of life in men. Both sexes displayed a slightly greater decline in ASM than in muscle mass (13 vs. 12%).
Conclusions
The present study provides normative values for absolute and relative muscle mass and ASM in Brazilian adults. Furthermore, important specific age-related changes in muscle mass parameters were observed. These data have public health implications and might serve as a reference tool to guide health professionals.
... They include the gait speed, the Short Physical Performance Battery (SPPB), and the stair climb power test (Table 3). A strong correlation was found between physical performance measures, body composition, and skeletal muscle parameters [60,61]. In addition, they have the ability to predict health-related outcomes, such as mortality, morbidity, and disability [62][63][64][65]. ...
Background
Sarcopenia is a syndrome characterized by a progressive decline in muscle mass and strength, with subsequent deterioration of functional performance and increased morbidity and mortality. Its emergence may be associated with disorders that are not limited to the elderly. The multifactorial nature of sarcopenia is a major barrier to diagnosis. Several risk factors contribute to the development of sarcopenia, including age, gender, and amount of physical activity. Additionally, the pathophysiology of sarcopenia involves inflammatory conditions, endocrinal dysfunction, and metabolic alterations. Several studies have proposed numerous molecules that may be linked to the pathogenesis of sarcopenia and could be useful in the future; however, there is an unmet need to discover a sensitive, reliable, and cost-effective biomarker of muscle aging.
Main text
The objective of this research is to highlight different biomarkers of sarcopenia that reflect its multifactorial pathophysiology. A narrative review was carried out through a series of literature searches in the database MEDLINE/PubMed focusing on sarcopenia biomarkers. The following search terms were used: “sarcopenia,” “osteosarcopenia,” “muscle ageing,” “muscle failure,” “sarcopenic obesity,” “weakness,” “biomarkers,” “frailty,” “comorbidity,” “functional disability,” and “inflamm-aging.” The studies were observational and peer-reviewed. They were all carried out at a referral center, hospital, or in the community. The articles chosen all contained information about sarcopenia. Case reports and articles that did not assess people's muscle aging and sarcopenia were not considered.
Conclusion
Despite the availability of numerous functional, imaging, and biological sarcopenia markers, the inherent limitations of the assessment tools make it difficult to objectively measure the various sarcopenia domains. A valid and reliable biomarker of sarcopenia has yet to be identified. The identification of “gold standard” evaluation techniques that should be systematically used is also impacted by the variability of the populations to be assessed. In this context, the establishment of an international consensus adopting a multi-biomarker approach may be of utmost importance to tackle the different aspects of this multifactorial health-related problem.
... The higher average muscle mass in Blacks than non-Blacks is well established [105][106][107][108][109][110][111][112][113][114][115][116][117][118][119], and persists when adjusted for age, sex, height, and body weight [120,121]. The National Health and Nutrition Examination Survey (NHANES), a nationally representative cross-sectional study of health and nutritional status in the US, reported that muscle mass averaged 11% greater among Blacks than Whites, a difference similar in magnitude to the higher GFR cr formula estimates assigned to Blacks [54]. ...
The best overall measure of kidney function is glomerular filtration rate (GFR) as commonly estimated from serum creatinine concentrations (eGFRcr) using formulas that correct for the higher average creatinine concentrations in Blacks. After two decades of use, these formulas have come under scrutiny for estimating GFR differently in Blacks and non-Blacks. Discussions of whether to include race (Black vs. non-Black) in the calculation of eGFRcr fail to acknowledge that the original race-based eGFRcr provided the same CKD treatment recommendations for Blacks and non-Blacks based on directly (exogenously) measured GFR. Nevertheless, the National Kidney Foundation and the American Society of Nephrology Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease removed race in CKD treatment guidelines and pushed for the immediate adoption of a race-free eGFRcr formula by physicians and clinical laboratories. This formula is projected to negate CKD in 5.51 million White and other non-Black adults and reclassify CKD to less severe stages in another 4.59 million non-Blacks, in order to expand treatment eligibility to 434,000 Blacks not previously diagnosed and to 584,000 Blacks previously diagnosed with less severe CKD. This review examines: 1) the validity of the arguments for removing the original race correction, and 2) the performance of the proposed replacement formula. Excluding race in the derivation of eGFRcr changed the statistical bias from +3.7 to -3.6 ml/min/1.73m² in Blacks and from +0.5 to +3.9 in non-Blacks, i.e., promoting CKD diagnosis in Blacks at the cost of restricting diagnosis in non-Blacks. By doing so, the revised eGFRcr greatly exaggerates the purported racial disparity in CKD burden. Claims that the revised formulas identify heretofore undiagnosed CKD in Blacks are not supported when studies that used kidney failure replacement therapy and mortality are interpreted as proxies for baseline CKD. Alternatively, a race-stratified eGFRcr (i.e., separate equations for Blacks and non-Blacks) would provide the least biased eGFRcr for both Blacks and non-Blacks and the best medical treatment for all patients.
... In a short period of approximately one year, comorbidities might not be directly related to muscle mass loss if they are stable. Magnetic resonance imaging (MRI) and computed tomography have been frequently used instead of DXA to measure muscle mass because of their accuracy [18,19]. However, lower limb lean mass measured by DXA has been found to be highly correlated with MRI measurements of skeletal muscle volume [20]. ...
Background
Under the restriction of social activities during the coronavirus disease 2019 (COVID-19) pandemic, there was concern about the loss of muscle mass due to a decrease in physical activity for the elderly. The purpose of this study was to investigate the characteristics of older patients with postmenopausal osteoporosis who developed loss of muscle mass during the COVID-19 pandemic in Japan.
Methods
A total of 54 patients with postmenopausal osteoporosis were evaluated in this study. Whole-body dual-energy X-ray absorptiometry was performed pre- and post-COVID-19 pandemic to measure trunk and lower limb muscle mass. At the time of the post-COVID-19 pandemic, we conducted a survey to compare lifestyle before pandemic (the frequency of going out, the frequency of meeting acquaintances or families living apart, regular exercise habits, walking time, family structure), and comorbidities between the muscle mass loss (ML) group and the muscle mass maintenance (MM) group. The ML group consisted of patients with at least a 5% decrease in lower limb muscle mass or trunk muscle mass.
Results
A significant difference was found only for the family structure (P = 0.0279); in the ML group, those living alone were the largest group, while in the MM group they were the smallest group.
Conclusions
The ML group was significantly more likely to live alone than the MM group. The current study showed that loss of muscle mass was more common in patients living alone.
... Using the baseline data of the Health ABC study, the association between muscle cross-sectional area and muscle tissue attenuation with functional performance (6-m walk and repeated chair stands) was investigated. After adjustment for several confounders including total body fat, a smaller muscle area as well as a lower muscle attenuation-indicative of greater fat infiltration in the muscle, were associated with poorer performance (28). ...
Background:
The Health, Aging and Body Composition (Health ABC) Study is a longitudinal cohort study started just over 25 years ago. This ground-breaking study tested specific hypotheses about the importance of weight, body composition and weight-related health conditions for incident functional limitation in older adults.
Methods:
Narrative review with analysis of ancillary studies, career awards, publications and citations.
Results:
Key findings of the study demonstrated the importance of body composition as a whole, both fat and lean mass, in the disablement pathway. The quality of the muscle in terms of its strength and its composition was found to be a critical feature in defining sarcopenia. Dietary patterns and especially protein intake, social factors and cognition were found to be critical elements for functional limitation and disability. The study is highly cited and its assessments have been widely adopted in both observational studies and clinical trials. Its impact continues as a platform for collaboration and career development.
Conclusions:
The Health ABC provides a knowledge base for the prevention of disability and promotion of mobility in older adults.
... In addition to visceral adiposity, ectopic fat (in the heart and muscle) contributes to cardiometabolic outcomes in individuals with overweight and obesity (Despres 2012). Furthermore, SO and fat infiltration into the muscle decrease muscle mass and performance (Visser et al. 2002). Therefore, reducing SO is essential to improve the quality of life. ...
This propensity score-matched cohort study investigated the effects of blood cadmium (Cd) levels on body composition. Body composition was assessed by multifrequency bioelectrical impedance analysis and categorized into three groups: metabolically healthy obesity (MHO), adiposity obesity (AO), and sarcopenic obesity (SO). At baseline, 85 and 101 participants had MHO and AO, respectively (mean age, 51 ± 7 years; male-to-female ratio, 1.0:1.3). During the 14-year follow-up, the body composition of 40 MHO and 6 AO participants deteriorated to AO and SO, respectively. The incidence of AO and SO differed according to age, sex, and blood Cd level. High blood Cd level increased the risk of body composition deterioration, particularly among those aged 60–69 years (hazard ratio [HR] = 2.14), women (HR = 1.46), and those with AO at baseline (HR = 1.63; all p < 0.05). Cd exposure deteriorates body composition in older and female individuals, particularly from AO to SO.
... It has long been assumed that age-related loss of weight, along with loss of muscle mass, is mainly responsible for weakness in older people [30]. Moreover, changes in muscle composition and fat infiltration lower muscle quality and function [34]. In conditions such as malignancy, lean body mass is lost, while fat mass may be preserved [30]. ...
Background:
Malnutrition and skeletal muscle waste (sarcopenia) are known as predictive factors for a poor postoperative outcome. Paradoxically, obesity seems to be associated with a survival advantage in wasting diseases such as cancer. Thus, the interpretation of body composition indices and their impact on rectal cancer therapy has become more and more complex. The aim of this study was to evaluate body composition indices in locally advanced rectal cancer patients prior to therapy and their impact on short- and long-term outcomes.
Methods:
Between 2008 and 2018, 96 patients were included in this study. Pre-therapeutic CT scans were used to evaluate visceral and subcutaneous fat mass, as well as muscle mass. Body composition indices were compared to body mass index, morbidity, anastomotic leakage rate, local recurrency rate, and oncological long-term outcomes.
Results:
Increased visceral fat (p < 0.01), subcutaneous fat (p < 0.01), and total fat mass (p = 0.001) were associated with overweight. Skeletal muscle waste (sarcopenia) (p = 0.045), age (p = 0.004), comorbidities (p < 0.01), and sarcopenic obesity (p = 0.02) were significantly associated with increased overall morbidity. The anastomotic leakage rate was significantly influenced when comorbidities were present (p = 0.006). Patients with sarcopenic obesity showed significantly worse disease-free (p = 0.04) and overall survival (p = 0.0019). The local recurrency rate was not influenced by body composition indices.
Conclusion:
Muscle waste, older age, and comorbidities were demonstrated as strong risk factors for increased overall morbidity. Sarcopenic obesity was associated with worse DFS and OS. This study underlines the role of nutrition and appropriate physical activity prior to therapy.
... While lower load resistance exercise has been discussed as a method to augment human strength and lean body mass, it should be noted that these outcomes are essential components of healthy living. Low muscle mass and strength are associated with poor physical function and are associated with future mobility impairment in older adults [32,33]. Additionally, a range of diseases can be positively influenced by enhancing an individual's strength and lean mass [34]. ...
Resistance training is a method of enhancing strength, gait speed, mobility, and health. However, the external load required to induce these benefits is a contentious issue. A growing body of evidence suggests that when lower load resistance training [i.e., loads < 50% of one-repetition maximum (1RM)] is completed within close proximity to concentric failure, it can serve as an effective alternative to traditional higher load (i.e., loads > 70% of 1RM) training and in many cases can promote similar or even superior physiological adaptations. Such findings are important given that confidence with external loads and access to training facilities and equipment are commonly cited barriers to regular resistance training. Here, we review some of the mechanisms and physiological changes in response to lower load resistance training. We also consider the evidence for applying lower loads for those at risk of cardiovascular and metabolic diseases and those with reduced mobility. Finally, we provide practical recommendations, specifically that to maximize the benefits of lower load resistance training, high levels of effort and training in close proximity to concentric failure are required. Additionally, using lower loads 2–3 times per week with 3–4 sets per exercise, and loads no lower than 30% of 1RM can enhance muscle hypertrophy and strength adaptations. Consequently, implementing lower load resistance training can be a beneficial and viable resistance training method for a wide range of fitness- and health-related goals.
... Height² correction of skeletal muscle mass index was first performed by Baumgartner and colleagues (16). Since then, multiple reports have utilized this index to define sarcopenia (17)(18)(19)(20). In this study, RFCSA measured by ultrasound adjusted by height² was defined as the rectus femoris mass index (RFMI). ...
Aims:
To assess the association of rectus femoris mass index (RFMI) with diabetic peripheral neuropathy (DPN) in individuals with type 2 diabetes mellitus (T2DM).
Methods:
Totally 948 T2DM cases were enrolled. Nerve conduction parameters, quantitative sensory threshold and rectus femoris cross-sectional area (RFCSA) were obtained, and rectus femoris mass index (RFMI=RFCSA/height2) was derived. The patients were assigned to four groups based on interquartile spacing of RFMI.
Results:
Motor/sensory nerve amplitude and conduction velocity (CV) were significantly lower in the low-level RFMI groups (all P<0.05). RFMI was positively associated with mean motor/sensory nerve amplitude and CV (both P<0.05). T2DM duration above 10 years and RFMI below 2.37cm²/m² had significant associations with DPN (both P<0.001). Receiver operating characteristic (ROC) curve analysis demonstrated cutoffs for T2DM duration and RFMI of 7 years and 2.2 cm²/m², respectively (AUC=0.75, 95% CI: 0.72-0.79; sensitivity, 68.4%; specificity, 66.8%).
Conclusion:
DPN is significantly associated with reduced RFMI in T2DM patients. Decreased muscle mass seems to be associated with motor/sensory nerve amplitude and CV. RFMI combined with T2DM duration may represent a potent tool for predicting DPN occurrence in T2DM cases.
Clinical trial registration:
http://www.chictr.org.cn, identifier ChiCTR2100049150.
... adults. 47,48 Thus, the combined effects of these age-related changes in lower extremity muscles may lead to compromised compensatory responses in older adults. ...
Although the ability to recover balance in the lateral direction has important implications with regard to fall risk in older adults, the effect of visual input on balance recovery in response to lateral perturbation and the effect of age are not well studied. We investigated the effect of visual input on balance recovery response to unpredictable lateral surface perturbations and its age-related changes. Ten younger and 10 older healthy adults were compared during balance recovery trials performed with the eyes open and eyes closed (EC). Compared with younger adults, older adults showed increased electromyography (EMG) peak amplitude of the soleus and gluteus medius, reduced EMG burst duration of the gluteus maximus and medius, and increased body sway (SD of the body’s center of mass acceleration) in EC. In addition, older adults exhibited a smaller % increase (EC—eyes open) of the ankle eversion angle, hip abduction torque, EMG burst duration of the fibularis longus, and a greater % increase of body sway. All kinematics, kinetics, and EMG variables were greater in EC compared with eyes open in both groups. In conclusion, the absence of visual input negatively affects the balance recovery mechanism more in older adults compared with younger adults.
... Skeletal muscle radiation attenuation is a common feature of aging and various metabolic diseases, including obesity and type 2 diabetes [27]. Studies have demonstrated that patients with AGHD have considerably lower skeletal muscle quantity and quality compared to healthy individuals [28] [29]. Our study found that at baseline, total body muscle volume was signi cantly higher in the IAGHD group than in the non-IAGHD group; this was mainly observed in normal attenuation muscle and concentrated in the skeletal muscle of the upper and lower extremities. ...
Objectives The aim of this study is to explore the specificity of baseline indicators in patients with IAGHD and investigate the potential differential therapeutic effects of short-term GH treatment on body composition distribution in IAGHD patients and non-IAGHD with established etiology. Methods Nineteen patients with IAGHD and 26 patients matched by basic data with non-IAGHD of definite etiology were included in this prospective, case–control study. All subjects underwent complete anthropometric and laboratory measurements at baseline and after 6 months of recombinant human GH replacement therapy. Of these patients, 13 IAGHD and 19 non-IAGHD patients underwent a quantitative assessment of body composition using deep learning software. Results Baseline: IAGHD group had higher height (p=0.025), LBM (p=0.009) and total body muscle (p=0.029), and lower WHR (p=0.034) compared to non-IAGHD group. Short-term GH therapy in non-IAGHD patients: Increased total body normal and abnormal attenuation muscle (p=0.035/p=0.009) and reduced IMF volume in upper limbs and abdomen (p=0.050/p=0.040), indicating positive body component redistribution. However, GH therapy resulted in increased weight (p=0.048) and waist circumference (p=0.038), decreased LBM and bilateral upper extremity muscle (p=0.028), and increased total body fat (p=0.046), intra-abdominal fat (p=0.004), torso visceral fat (p=0.038), AVF (p=0.017), and bilateral upper and proximal lower extremity SF volume in IAGHD patients (p=0.015/p=0.038). HOMA-IR in IAGHD patients was significantly correlated with adipose-related parameters. Conclusion There were significant differences in the clinical parameters of IAGHD patients at baseline, and short-term GH replacement therapy appeared to be detrimental to the redistribution of body composition in IAGHD patients.
... 1,2 Fat accumulations in and around skel etal muscle can interfere with force production. [3][4][5] Ultrasonography is a relatively inexpensive, non-inva sive modality that is useful for measuring muscle architec ture and subcutaneous fat accumulations. Not only does this technology advance the study of muscle architecture in un derstanding force production, it offers an important capacity for clinical practice. ...
Purpose: This cross-sectional study determines the sensitivity of muscle architecture and fat measurements of the rectus femoris (RF) and vastus lateralis (VL) muscles from ultrasound images acquired with varying transducer tilt, using a novel transducer attachment, in healthy adults. Secondary objectives were to estimate intrarater and interrater reliability of image measurement and acquisition, respectively. Methods: Thirty healthy adults participated (15 women and 15 men; 25 [SD 2.5] y). Ultrasound image acquisition was conducted by two raters at different transducer tilts relative to the skin: estimated perpendicular, and five measured angles (80°, 85°, 90°, 95°, 100°) using the transducer attachment. Muscle thickness (MT), subcutaneous fat thickness (FT), pennation angle (PA), and fascicle length (FL) were measured. Sensitivity and reliability were assessed using intra-class correlation coefficients (ICCs) and standard error of measurements (SEMs). Results: MT and FT for RF and VL were not sensitive to transducer tilt. However, PA and FL were sensitive to transducer tilt. MT and FT for both muscles showed high ICCs and low SEMs for intrarater and interrater reliability. For PA of both muscles, standardizing transducer tilt improved interrater ICCs and lowered SEMs. Conclusion: MT and FT measurements of RF and VL acquired at 60° knee flexion are robust to varying transducer tilt angles. PA measurements benefit from standardizing transducer tilt.
... First, when evaluating sarcopenia in this study, various physical performance such as grip strength and gait speed were not evaluated. However, according to several previous studies, appropriate muscle mass and lean mass are used as variables that can represent physical performance (56)(57)(58). Second, this study did not accurately measure the content of caffeine consumed and did not completely exclude the possibility of the interference of other substances that can supply antioxidants such as green tea, milk, vegetables, and fruits. ...
This study assessed the association between sarcopenic obesity (S+O+) and coffee
intake in elderly Koreans. This study obtained data from the Korea National Health and Nutrition Examination Survey (KNHANES, 2008–2011), a cross-sectional and nationally representative survey conducted by the Korean Centers for Disease Control and Prevention. Of the 2,661 participants included in this study, there was a significant difference between 5.861 (95% CI 2.024–16.971) in less than one cup of coffee, and 6.245 (95% CI 2.136–18.260) in one cup of coffee, and 4.323 (95% CI 1.457–12.824) in two cups of coffee compared to three or more than cups of coffee. In contrast, in the case of sarcopenia or obesity only (S+O- or S-O+), no significant difference was found in any model. The results suggest that the elderly who consume less than one cup of coffee per day had a greater risk of S+O+ than those who consume more than three cups per day. Furthermore, there was an association between coffee intake and sarcopenia but not with obesity. Therefore, coffee intake may have prevented musculoskeletal loss in these patients.
... Muscle function has been shown as a more powerful predictor of clinically significant outcomes in elderly than muscle mass alone, and the muscle strength is considered the most reliable parameter to measure muscle function [4][5][6]. In addition, morphological insights into skeletal muscle composition suggested that fat accumulation within skeletal muscle is associated with lower muscle strength and increased risk of incident limitations in mobility [7,8], as well as poor function and increased risk of incident falls in elderly [9,10]. The most recent definition introduced by the European Working Group on Sarcopenia in Older People (EWGSOP2) in 2019 defines sarcopenia as a progressive, generalized skeletal muscle disorder, involving the accelerated loss of muscle function and muscle mass or quality [6]. ...
Background:
Sarcopenia is an age-related progressive, generalized skeletal muscle disorder involving the accelerated loss of muscle function and muscle mass. The aim of this study was to assess the complex relationship between sarcopenia, malnutrition, cognitive impairment, physical activity, and depression in the elderly, with the potential role of quality of life as a mediator in these associations.
Methods:
A cross-sectional study was conducted on a sample (n = 298) of elderly patients admitted to Special Hospital for Rehabilitation "Termal", Vrdnik, Serbia. Sarcopenia, the risk for malnutrition, cognitive impairment, physical activity, quality of life, and depressive symptoms were measured by standardized instruments. Additional data included sociodemographic characteristics. Simultaneous assessment of the direct and indirect relationships of all determinants was performed by path analysis.
Results:
A total of 40% (n = 120) of the elderly were diagnosed with sarcopenia, and 42.6% had depression symptoms. The risk of malnutrition was present in 23.5%, cognitive impairment in 5.4%, and a low level of physical activity was reported in 26.2% of elderly participants. The mean reported quality of life measured by Sarcopenia and Quality of Life Questionnaire was 60 (on the scale ranging from 0 to 100; where a higher score reflects a higher quality of life). The best-fitted model (χ2/DF = 1.885, NFI = 0.987, CFI = 0.993, GFI = 0.997, RMSEA = 0.055) highlighted the mediating effect of quality of life between sarcopenia, malnutrition, cognitive impairment, lower level of physical activities and depression. According to the model, quality of life was a direct negative predictor of depressive symptoms in the elderly, while malnutrition positively affected depression.
Conclusions:
The presented path model may assist rehabilitation centers in developing strategies to screen for sarcopenia and risk of malnutrition, and promote physical activity in elderly, aiming to prevent their negative effects on mental health. For the elderly currently affected by sarcopenia, we consider regenerative medicine and stem cell therapy, which, in view of their etiology, could be a potential therapeutic strategy for sarcopenia.
... Previous studies have shown that PhA is positively correlated with cell membrane integrity and cell function. When the cell membranes are intact and the cell functions are complete PhA increases, but the situation is the opposite when the cell membranes are damaged and the selective filtration function is reduced (13)(14)(15)(16). In healthy people, PhA has been shown to be associated with age, gender, BMI, life factors, and race (17,18). ...
Sarcopenia is commonly defined as the age-related loss of muscle mass and function and may be caused by several factors, such as genetics, environmental conditions, lifestyle, drug use, and, in particular, comorbidities. People with pre-existing conditions are more likely to develop sarcopenia and subsequently have a less favorable prognosis. Recently, phase angle (PhA), which is derived from bioelectrical impedance analysis (BIA), has received a great deal of attention, and numerous studies have been carried out to examine the relationship between PhA and sarcopenia in different conditions. Based on these studies, we expect that PhA could be used as a potential marker for sarcopenia in the future.
... A decline in muscle strength is one typical physical dysfunction in older adults. Epidemiological studies have reported that age-related weakness in muscle strength in older adults was associated with decreases in fundamental ADLs such as walking, rising from a chair, and climbing stairs (Bean et al., 2002(Bean et al., , 2003, and with increased risk of developing diseases such as diabetes, osteoporosis, and heart disease (Visser et al., 2002). Randomized controlled trials (RCT) showed that high-intensity resistance exercise training is effective for improving muscle weakness and physical frailty in very old adults (Fiatarone et al., 1994). ...
Aim
The purpose of this systematic review and meta-analysis was to investigate the effects of low-intensity resistance training on knee extension strength with respect to intensity, frequency, duration and training site in community-dwelling older adults.
Methods
A literature search was conducted for articles published up to December 2018 on PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Physiotherapy Evidence Database (PEDro), OTseeker and Ichushi-Web. Randomized controlled trials involving resistance training with <60 % one repetition maximum (1RM) in community-dwelling older adults aged 60 years and older were eligible.
Results
In total, 7 studies involving 275 participants were included in the meta-analysis. The results showed significant improvements in knee extension strength with low-intensity resistance training [standardized mean difference (SMD) 0.62, 95 % confidence interval (CI) 0.32 to 0.91]. In subgroup analyses, significant improvements were observed in the group with intensity at 50–60 % 1RM (0.83, 0.46 to 1.19), but not in the group at 40 % or less 1RM (0.30, 95%CI: −0.08 to 0.68). Concerning frequency, there were significant improvements in knee strength for those receiving training three times (0.90, 0.52 to 1.27) and two times (0.36, 0.03 to 0.69) per week, with a significant difference between the groups (p = 0.04).
Conclusions
Low-intensity resistance training should be considered as an effective intervention to improve knee extension strength in community-dwelling older adults. Older adults may show more improvement in knee extension strength if intensity of the training is set at 50–60 % 1RM and frequency of training is three times per week.
... The impact of adiposity in both, ageing and obesity, lies in their association with morphological changes resulting from increased deposition of lipid within muscle fibers. Age-related lipid infiltration contributes to frailty by reducing muscle strength 72 . Obesity is also associated with a marked increase in lipid accumulation within muscle fibers 73 . ...
Objectives:
The objectives were to estimate prevalence of obesity among frail individuals aged ≥80 years and examine the association of obesity with cognitive impairment and depression among frail individuals aged ≥80 years.
Methods:
Two-hundred community-dwelling participants aged ≥80 years, were enrolled; 166 frail participants were further analyzed. Obesity and adiposity were determined by Body Mass Index (BMI), Waist Circumference (WC) and Body Fat Percentage (BF%). Cognitive impairment and Depression were assessed using Mini Mental State Examination (MMSE) and Geriatric Depression Scale (GDS-15). Frailty was assessed by Fried criteria. Chi-Square, t-test, trend-analysis and Logistic Regression (LR) were done.
Results:
Obesity among Frail individuals aged ≥80 years was 40% using BMI and 73.2% using WC. Obesity was inversely associated with cognitive impairment and depression among frail individuals. Severity of cognitive impairment and depression was lower among obese frail than non-obese frail. Trend-analysis showed decreasing cognitive impairment and depression with increasing BF%. On LR, obesity among frail individuals had inverse association with cognitive impairment and depression.
Conclusion:
Obesity among frail individuals aged ≥80 years was associated with lower odds of cognitive impairment and depression in our population. Positive effects of weight gain in oldest old frail individuals and development of cognitive impairment and dementia should be explored in further researches.
... Although physical health indicators, such as height and weight, among Chinese adults improved from 2014 to 2020, physical fitness parameters, such as strength, flexibility, and agility, continue to decline, with percentages of 0.5, 3.8, and 1.8, respectively [1]. Maintaining good physical fitness is crucial for maintaining good overall health, as a decline in physical fitness is associated with negative health effects, such as functional impairment [2], poor bone health [3], disability [4], and poor mental health [5]. Early adulthood is an important period for habit formation [6], and developing good physical fitness during this period has the potential to have far-reaching consequences [7]. ...
Reportedly, daytime napping affects the physical fitness of athletes. However, results of these studies are conflicting, and may not be generalizable to all populations. Early adulthood is an important period linking adolescents and adults, during which building good physical fitness is crucial for their remaining lives. Thus, we investigated whether daytime napping duration is associated with physical fitness among Chinese university students. This study was based on an annual physical health examination for all university students and included 11,199 participants (6690 males; 4509 females). The daytime napping duration was assessed using a self-report questionnaire. Physical fitness was measured with a 50 m sprint; 1000 m (for males) and 800 m (for females) runs; standing long jump, sit-and-reach, pull-up (for males), and sit-up (for females) tests; and vital capacity. The adjusted association was evaluated using analysis of covariance. Of the participants, 86% napped regularly. After covariate adjustment was performed, significant V-shaped associations were observed between the daytime napping duration and the 50 m sprint and 800 m run results in males and females. Inverted V-shaped associations were observed between the daytime napping duration and the sit-and-reach, standing long jump, and pull-up test performances and vital capacity in males and between the daytime napping duration and the standing long jump test performance in females. Daytime napping for <30 min may have beneficial effects on physical fitness among university students.
... Regions of interest for evaluating muscle mass from images contain non-contractile elements, including fat and fibrous tissues. Thus, there is an issue that the actual muscle contraction element is overestimated when the non-contractile element increases within the muscle [27][28][29]. This potential effect may have been the reason why the indicator of muscle mass was not associated with future functional disabilities or symptom worsening in patients with KOA. ...
Patients with knee osteoarthritis (OA) experience muscle quality loss, and is characterized by the enhanced echo intensity (EI) of the vastus medialis (VM) muscles and a high extracellular water-to-intracellular water (ECW/ICW) ratio of the thigh. This study aimed to elucidate the association between muscle degeneration and the worsening of functional disabilities and symptoms in patients with KOA over 3 years duration. Thirty-three patients with KOA who completed follow-up over 3 years were included in the analysis. The knee scoring system (KSS) was used to evaluate the functional abilities and symptoms. Based on the 3 years change in KSS scores, patients were classified into progressive or non-progressive groups. Muscle thickness (MT) and EI of the VM were determined using ultrasonography. The ECW/ICW ratio was measured using segmental-bioelectrical impedance spectroscopy. Multivariable logistic regression analyses were conducted with the groups as the dependent variables and VM-MT, VM-EI, and ECW/ICW ratio at baseline as independent variables, including potential confounders. Thirteen (39.4%) patients showed progressive features. VM-EI at baseline was significantly associated with the progression of functional disabilities (adjusted odds ratio [OR] 1.24; 95% confidence interval [CI] 1.03 − 1.50) and symptoms (adjusted OR 1.13; 95% CI 1.01 − 1.25). Enhanced VM-EI was associated with the worsening of functional disabilities and symptoms in patients with KOA over a period of 3 years. Therefore, the assessment of VM-EI using ultrasonography is a useful indicator for predicting the future worsening of KOA.
... The identified association between low muscle quality (muscle radiation attenuation) and a prolonged hospital stay is interesting. A low muscle radiation attenuation indicates an increased level of muscle fat infiltration [19] and previous studies have concluded that a low muscle radiation attenuation increase the risk of mobility limitations [4,20]. Whether low muscle radiation attenuation evaluated by CT scan can be a useful predictor of prolonged hospital stay and to identify patients at risk, requires further research. ...
Objectives:
The aim of this study was to investigate the potential correlation between muscle mass/muscle quality and risk of complications or recurrence in patients presenting with acute uncomplicated diverticulitis. It was also to study if low muscle mass/quality correlated to prolonged hospital stay.
Materials and methods:
The study population comprised 501 patients admitted to Helsingborg Hospital or Skåne University Hospital between 1 January 2015 and 31 December 2017, who had been diagnosed with acute uncomplicated diverticulitis and undergone computed tomography upon admission. The scans were used to estimate skeletal muscle mass and muscle radiation attenuation (an indicator for muscle quality). Skeletal muscle index was obtained by adjusting skeletal muscle mass to the patients' height. Values of below the fifth percentile of a normal population were considered low.
Results:
There were no differences between the patients with normal versus those with low skeletal muscle mass, skeletal muscle index or muscle radiation attenuation regarding risk of complications or recurrence of diverticular disease. However, as only 11 patients had complications, no conclusion as to a potential correlation can be made. Low muscle quality correlated to longer hospital stay, also when adjusting for other potential confounders.
Conclusions:
Muscle mass/quality do not seem to serve as predictor of risk for recurrent disease in patients with acute uncomplicated diverticulitis. However, low muscle radiation attenuation was associated with prolonged hospital stay. This indicates that muscle quality, assessed by computed tomography scan, might be used in clinical practise to identify patients at risk of longer hospitalisation.
... Obviously, there are other surveys regarding the relationship between body composition, nutrition and physical ability. Some of them show that a high percentage of fat and low muscle mass are associated with functional decline [4,[27][28][29] and, to be more detailed, higher tFMI (trunk fat mass index) using DXA was correlated with low physical performance and balance [30,31] but, on the other hand, a positive correlation was found between physical activity and lean mass [31][32]. ...
Objectives:
The aim of the study was to assess the relationship between body composition, nutritional status and physical ability in elderly outpatients.
Method:
. In this cross-sectional study, demographic data and medical history were collected from patients aged ≥60 years followed in the Geriatric Outpatient Clinic from October 2010 to February 2014. Body composition was examined using a dual-energy X-ray absorptiometry. Physical performance was assessed by gait speed (GS), Timed Up&Go Test (TUG), Six Minute Walk Test (6MWT). The nutritional status was evaluated using the Mini Nutritional Assessment (MNA) and serum albumin level.
Results:
Mean age (± SD) of 76 patients (64.47% men) was 71.93 ± 8.88 yrs. The most common diseases were: hypertension (89.47%), coronary heart disease (81.58%) and chronic heart failure (68.4%). In multiple regression analyses, the factors significantly affecting GS were: age (B = - 0.017, p ≤0.0001), good nutritional status (B = 0.038, p <0.01) and percent of lower extremity fat (B = - 0.009, p <0.05). Longer TUG time was associated with poorer nutritional status (B = -0.031, p <0.01), older age (B = 0.01, p <0.01) and a higher number of comorbidities (B = 0.034, p <0.05). 6MWT was influenced negatively by age (B = -3.805, p <0.01) and percent of lower extremity fat (B = -2.474, p <0.05).
Conclusions:
Age and nutritional status remain a strong determinant of physical fitness deterioration. Different measures of physical performance are influenced by different elements of body composition - no single element of body composition was found determining the deterioration of all assessed parameters of physical fitness. Identifying the relationship between body composition, nutritional status and physical performance can help elucidate the causes of disability and target preventive measures.
Objectives
:To determine how muscle strength, power, mass, and density ( i.e . quality) differ between children living with HIV (CWH) and those uninfected, and whether antiretroviral therapy (ART) regime is associated with muscle quality.
Design
:A cross-sectional study in Harare, Zimbabwe.
Methods
:The study recruited CWH aged 8–16years, taking ART for ≥2years, from HIV clinics, and HIV-uninfected children from local schools. Muscle outcomes comprised grip strength measured by hand-held Jamar dynamometer, lower-limb power measured by standing long-jump distance, lean mass measured by dual-energy X-ray absorptiometry, and muscle density (reflecting intramuscular fat) by peripheral quantitative computed tomography. Linear regression calculated adjusted mean differences (aMD) by HIV status.
Results
:Overall, 303 CWH and 306 without HIV, had mean(SD) age 12.5(2.5) years, BMI 17.5(2.8), with 50% female. Height and fat mass were lower in CWH, mean differences(SE) 7.4(1.1)cm and 2.7(0.4)kgs, respectively. Male CWH had lower grip strength (aMD 2.5[1.1,3.9]kg, P < 0.001), long-jump distance (7.1[1.8,12.5]cm, P = 0.006), muscle density (0.58[0.12,1.05]mg/cm ³ , P = 0.018, but not lean mass 0.06[-1.08,1.21]kg, P = 0.891) versus boys without HIV; differences were consistent but smaller in females. Mediation analysis suggested the negative effect of HIV on jumping power in males was partially mediated by muscle density ( P = 0.032). CWH taking tenofovir disoproxil fumarate (TDF) had lower muscle density (0.56[0.00,1.13]mg/cm ³ , P = 0.049) independent of fat mass, than CWH on other ART.
Conclusions
:Perinatally-acquired HIV is associated, particularly in males, with reduced upper and lower-limb muscle function, not mass. Intra-muscular fat (poorer muscle quality) partially explained reductions in lower-limb function. TDF is a novel risk factor for impaired muscle quality.
Objective:
Skeletal muscle quality and mass are important for maintaining physical function during advancing age. We leveraged baseline data from REPRIEVE to evaluate whether paraspinal muscle density and muscle area are associated with cardiac or physical function outcomes in people with HIV (PWH).
Methods:
REPRIEVE is a double-blind randomized trial evaluating the effect of pitavastatin for primary prevention of major adverse cardiovascular events (MACE) in PWH. This cross-sectional analysis focuses on participants who underwent coronary CT at baseline. Lower thoracic paraspinal muscle density (Hounsfeld units, HU) and area (cm2) were assessed on non-contrast CT image.
Results:
Of 805 PWH, 708 had paraspinal muscle measurements. Median age was 51 years; 17% were natal female. Median muscle density was 41 HU (male), 30 HU (female); area 13.2 cm2/m (male) and 9.9 cm2/m (female). In adjusted analyses, greater density (less fat) was associated with lower prevalences of any coronary artery plaque, coronary artery calcium score >0, and high plaque burden (p=0.06); area was not associated with plaque measures. Among 139 with physical function measures, greater area (but not density) was associated with better performance on a short physical performance battery and grip strength.
Conclusions:
Among PWH, greater paraspinal muscle density was associated with lower prevalence of coronary artery disease, while greater area was associated with better physical performance. Whether changes in density or area are associated with changes in CAD or physical performance will be evaluated through longitudinal analyses in REPRIEVE.
Background:
Obesity and loss of muscle mass are emerging as risk factors for dementia, but the role of adiposity infiltrating skeletal muscles is less clear. Skeletal muscle adiposity increases with older age and especially among Black women, a segment of the US population who is also at higher risk for dementia.
Methods:
In 1634 adults (69-79 years, 48% women, 35% Black), we obtained thigh intermuscular adipose tissue (IMAT) via computerized tomography at Years 1 and 6, and mini-mental state exam (3MS) at Years 1, 3, 5, 8 and 10. Linear mixed effects models tested the hypothesis that increased IMAT (Year 1-6) would be associated with 3MS decline (Year 5-10). Models were adjusted for traditional dementia risk factors at Year 1 (3MS, education, APOe4 allele, diabetes, hypertension, and physical activity), with interactions between IMAT change by race or sex. To assess the influence of other muscle and adiposity characteristics, models accounted for change in muscle strength, muscle area, body weight, abdominal subcutaneous and visceral adiposity, and total body fat mass (all measured in Years 1 and 6). Models were also adjusted for cytokines related to adiposity: leptin, adiponectin, and interleukin-6.
Results:
Thigh IMAT increased by 4.85 cm2 (Year 1-6) and 3MS declined by 3.20 points (Year 6-10). The association of IMAT increase with 3MS decline was statistically significant: an IMAT increase of 4.85 cm2 corresponded to a 3MS decline of an additional 3.60 points (p < 0.0001), indicating a clinically important change. Interactions by race and sex were not significant.
Conclusions:
Clinicians should be aware that regional adiposity accumulating in the skeletal muscle may be an important, novel risk factor for cognitive decline in Black and White participants independent of changes to muscle strength, body composition and traditional dementia risk factors.
BACKGROUND
Myostatin, a cytokine produced by skeletal muscle, may influence Alzheimer’s Disease (AD) pathogenesis, but sparse evidence exists in humans. We assessed the association between circulating levels of myostatin at year 1 and plasma levels of β-amyloid 42/40 at year 2, a marker of AD pathology, in a biracial cohort of older adults.
METHODS
We studied 403 community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from Memphis, Tennessee, and Pittsburgh, Pennsylvania. Mean age was 73.8± 3 years; 54% were female; and 52% were Black. Serum myostatin levels were measured at year 1, plasma β-amyloid 42/40 levels in year 2 (higher ratio indicating lower amyloid load). Multivariable linear regression analyses tested the association of serum myostatin with plasma levels of β-amyloid 42/40 adjusted for computed tomography derived thigh muscle cross-sectional area, demographics, APOe4 allele, and risk factors for dementia. We tested for two-way .interactions between myostatin and race or sex; results were stratified by race and sex
RESULTS
In multivariable models, myostatin was positively associated with plasma levels of β-amyloid 42/40 (standardized regression coefficient: 0.145, p=0.004). Results were significant for white men and women (0.279, p=0.009, and 0.221, p=0.035, respectively) but not for black men or women; interactions by race and gender were not statistically significant.
CONCLUSIONS
Higher serum myostatin was associated with lower amyloid burden, independently of APOe4 alleles, muscle area and other established risk factors for dementia. The role of myostatin in AD pathogenesis, and the influence of race should be further investigated.
Sarcopenia is the loss of muscle strength, mass, and function, which is often exacerbated by chronic comorbidities including cardiovascular diseases, chronic kidney disease, and cancer. Sarcopenia is associated with faster progression of cardiovascular diseases and higher risk of mortality, falls, and reduced quality of life, particularly among older adults. Although the pathophysiologic mechanisms are complex, the broad underlying cause of sarcopenia includes an imbalance between anabolic and catabolic muscle homeostasis with or without neuronal degeneration. The intrinsic molecular mechanisms of aging, chronic illness, malnutrition, and immobility are associated with the development of sarcopenia. Screening and testing for sarcopenia may be particularly important among those with chronic disease states. Early recognition of sarcopenia is important because it can provide an opportunity for interventions to reverse or delay the progression of muscle disorder, which may ultimately impact cardiovascular outcomes. Relying on body mass index is not useful for screening because many patients will have sarcopenic obesity, a particularly important phenotype among older cardiac patients. In this review, we aimed to: (1) provide a definition of sarcopenia within the context of muscle wasting disorders; (2) summarize the associations between sarcopenia and different cardiovascular diseases; (3) highlight an approach for a diagnostic evaluation; (4) discuss management strategies for sarcopenia; and (5) outline key gaps in knowledge with implications for the future of the field.
Aim:
Identifying plasma molecules associated with skeletal muscle properties can elucidate the pathophysiology of sarcopenia. Because adipocytokines are a promising candidate marker, the current study aimed to clarify the possible associations between adiponectin and leptin levels and mid-thigh muscle cross-sectional area and mean attenuation value, which are indices of muscle mass and fat deposition in muscle, respectively.
Methods:
The current study included 1440 older Japanese adults (mean age 69.3 years). Mid-thigh skeletal muscle cross-sectional area and mean attenuation value were evaluated through computed tomography scan. A low attenuation value showed a greater fat deposition in muscle. Circulating adiponectin and leptin levels were assessed using blood specimens collected during the baseline investigation.
Results:
Plasma leptin level was inversely correlated with muscle cross-sectional area, but not with attenuation value. The association with cross-sectional area was independent of possible confounding factors including body size (Q1: reference; Q2: β = -0.032, P = 0.033; Q3: β = -0.064, P < 0.001; Q4: β = -0.111, P < 0.001). In contrast, adiponectin level was independently and inversely associated with attenuation value (Q1: reference; Q2: β = -0.044, P = 0.122; Q3: β = -0.080, P = 0.006; Q4: β = -0.159, P < 0.001), but not with cross-sectional area. These associations between adipocytokine levels and muscle properties were independent of abdominal fat area and insulin resistance.
Conclusions:
There were adiposity- and insulin resistance-independent associations between adipocytokines levels and skeletal muscle mass and fat deposition in muscle, suggesting an involvement of adipocytokines in muscle properties. Geriatr Gerontol Int 2023; ••: ••-••.
The definition of sarcopenia, the age-related loss of muscle mass, has evolved since the term's inception and yet there is no consensus. Many of the identified definitions of sarcopenia centre their criteria around the loss of muscle mass, loss of function, and weakness. Common variables to various definitions of sarcopenia are appendicular lean soft tissue mass (often called muscle mass), grip strength, and gait speed. However, a lack of consensus remains among operational definitions and diagnostics for this newly recognized disease may be attributed to the absence of appropriate tools that accurately measure the outcomes of interest, such as skeletal muscle instead of lean mass. In this narrative review, we describe the evolution of the consensus group' definition of sarcopenia, address the need for more accurate measures of muscle mass and function, and effective, low-cost treatments (i.e., resistance training and diet) for this disease. Consensus on what constitutes sarcopenia is critical to propel research in the field and, importantly, provide what prognostic value a sarcopenia diagnosis provides and how such a patient would be treated.
Background:
Falls in pre-frail older adults is often attributed to poor physical performance, lower muscle quality and quantity. The aims of our study were to determine (i) demographics, physical function, and body composition in pre-frail older adults with poor physical performance (ii) characteristics of fallers amongst those with poor physical performance and (iii) association of physical function and body composition measures with falls in pre-frail older adults with poor physical performance.
Methods:
Cross-sectional study of 328 pre-frail community-dwelling older adults ≥ 60 years. Data was collected on demographics, cognition, short physical performance battery (SPPB) and gait speed. Poor physical performance was defined by SPPB ≤ 9, 5x chair-stand time ≥12 s or gait speed <1 m/s. InBody S10 used to measure body composition.
Results:
Mean age 72.51 years, 185(56.4%) females, 276(84.1%) of Chinese ethnicity and 257 (78.4%) had poor physical performance. Within the poor performers, SPPB balance (OR 0.50; 95% CI 0.27-0.92; p = 0.025) and 5x-chair-stand (OR 1.09; 95% CI 1.01-1.18; p = 0.038) in addition to higher body fat percentage, fat mass index, fat mass to fat free mass ratio, all segmental lean masses except for left leg and body cell mass were significantly associated with falls.
Conclusions:
Longer chair-stand time, lower balance, low muscle and high fat mass are associated with falls in poor performers and could serve as screening tools for those at increased risk of falls. The findings from our study need to be validated prospectively in a larger population study.
Background:
Adherence to a healthy diet is inversely associated with frailty. However, the relationship between nuts, a key food group of Mediterranean diet, and frailty is unclear.
Objectives:
This study aimed to evaluate the association between nut consumption and frailty in an aging female population.
Methods:
This population-based observational study included nonfrail women (≥60 y old) in the NHS from 11 states of the United States. Outcome was incident frailty, defined as having ≥3 of the FRAIL components (fatigue, lower strength, reduced aerobic capacity, multiple chronic conditions, and significant weight loss) and assessed every 4 y from 1992 to 2016. From 1990 to 2014, FFQs were used to assess the intakes of peanuts, peanut butter, walnuts (added in 1998), and other nuts at 4-y intervals. Exposure was total nut consumption, calculated as the sum of intakes of peanuts, peanut butter, walnuts, and other nuts and categorized into <1 serving/mo, 1-3 servings/mo, 1 serving/wk, 2-4 servings/wk, and ≥5 servings/wk. The relations of intakes of peanuts, peanut butter, and walnuts with frailty were also investigated separately. Cox proportional hazards models were used to assess the associations between nut consumption and frailty after adjusting for age, smoking, BMI, EI, diet quality, and medication use.
Results:
Among 71,704 participants, 14,195 incident frailty cases occurred over 1,165,290 person-years. The adjusted HR (95% CI) for consuming ≥5 servings/wk of nuts was 0.80 (0.73, 0.87), as compared with <1 serving/mo. Higher intakes of peanuts and walnuts, but not peanut butter, were also inversely associated with frailty.
Conclusions:
This large prospective cohort study showed a strong and consistent inverse association between regular nut consumption and incident frailty. This suggests that nut consumption should be further tested as a convenient public health intervention for the preservation of health and well-being in older adults.
Intermuscular adipose tissue (IMAT) is a distinct adipose depot described in early reports as a 'fatty replacement' or 'muscle fat infiltration' that was linked to ageing and neuromuscular disease. Later studies quantifying IMAT with modern in vivo imaging methods (computed tomography and magnetic resonance imaging) revealed that IMAT is proportionately higher in men and women with type 2 diabetes mellitus and the metabolic syndrome than in people without these conditions and is associated with insulin resistance and poor physical function with ageing. In parallel, agricultural research has provided extensive insight into the role of IMAT and other muscle lipids in muscle (that is, meat) quality. In addition, studies using rodent models have shown that IMAT is a bona fide white adipose tissue depot capable of robust triglyceride storage and turnover. Insight into the importance of IMAT in human biology has been limited by the dearth of studies on its biological properties, that is, the quality of IMAT. However, in the past few years, investigations have begun to determine that IMAT has molecular and metabolic features that distinguish it from other adipose tissue depots. These studies will be critical to further decipher the role of IMAT in health and disease and to better understand its potential as a therapeutic target.
Background:
The extent of asymmetry in the muscle tissue composition ratios with hip fractures has not been clarified.
Objective:
To determine whether there is a difference in the muscle tissue composition ratios between the fractured and non-fractured sides of the trunk and thighs immediate measurement.
Methods:
Forty-four patients (84.6 ± 7.0 years) were included. Computed tomography images were used for measurements. The muscle tissue composition ratio was measured using muscle cross-sectional area (CSA) and attenuation coefficient (Hounsfield units; HU). Defined each HU attenuation range as follows: low-density muscle (LDM), low-quality muscle tissue with fat infiltration, normal-density muscle (NDM), muscle contractor tissue, and intramuscular adipose tissue (IMAT), fat infiltration tissue. The CSA of each muscle tissue was expressed as a percentage: %LDM, %NDM, and %IMAT. A paired t-test was performed for comparison.
Results:
The %LDM on the fractured side was higher in the thigh and erector spinae. The %NDM on the fractured side was lower in the thigh. There was no significant difference in the %IMAT for all muscles.
Conclusion:
The thigh on the fractured side showed asymmetry with low %NDM and high %LDM. This characteristic captures a characteristic of muscle tissue that may have importance in hip fracture etiology.
Objectives
The diagnostic utility of poor body composition measures in sarcopenia remains unclear. We hypothesize that the skeletal muscle gauge [combination of skeletal muscle mass index (SMI) and skeletal muscle density (SMD); SMG = SMI × SMD] would have significant diagnostic and predictive value in certain regions and populations.
Design
Prospective cross-sectional study.
Setting and Participants
We examined inpatients age ≥60 years with or without cancer and with gastrointestinal disorders.
Methods
We used computed tomography (CT) image metrics in the 12th thoracic (T12), third lumbar (L3), erector spinae muscle (ESM), and psoas muscle (PM) regions to establish correlations with the 2019 Asian Working Group for Sarcopenia Consensus and used receiver operating characteristic area under the curve (AUC) to compare differences between metrics. Associations between CT metrics and mortality were reported as relative risk after adjustments.
Results
We evaluated 385 patients (median age, 69.0 years; 60.8% men) and found consistent trends in cancer (49.6%) and noncancer (50.4%) cohorts. SMG had a stronger correlation with muscle mass than SMD [mean rho: 0.68 (range, 0.59‒0.73) vs 0.39 (range, 0.28‒0.48); all P < .05] in T12, L3, and PM regions and a stronger correlation with muscle function than SMI [mean rho: 0.60 (range, 0.50‒0.77) vs 0.36 (range, 0.22‒0.58); all P < .05] in T12, ESM, and L3 regions. SMG outperformed SMI in diagnostic accuracy in all regions, particularly for L3 (AUC: 0.87‒0.88 vs 0.80‒0.82; both P < .05). PM gauge and L3SMG did not differ, whereas EMG (ESM gauge) or T12SMG and L3SMG did (AUC: 0.80‒0.82 vs 0.87‒0.88; all P < .05). L3SMI, L3SMD, T12SMG, EMG, and PM gauge showed no association with 1-year cancer-related mortality after adjusting for confounders; however, L3SMG [relative risk = 0.92 (0.85‒0.99); P = .023) was.
Conclusions and Implications
L3SMG covers all features of sarcopenia with more diagnostic value than other metrics, allowing a complete sarcopenia assessment with CT alone and not just in populations with cancer.
The study aimed to explore the impact of low skeletal muscle mass and quality on survival outcomes and treatment tolerance in patients undergoing radical chemo-radiation therapy for head and neck cancer (HNC). This is significant given the growing interest in sarcopenia as a possible negative predictive/prognostic factor of disease progression and survival. From 2010 to 2017, 225 patients were included in the study. Pre-treatment computed tomography (CT) scans of HNC patients undergoing (chemo)radiation therapy were retrospectively reviewed. The skeletal muscle area, normalized for height to obtain the skeletal muscle index (SMI), the skeletal muscle density (SMD) and the intramuscular adipose tissue area (IMAT) were measured at the level of the L3 vertebra. Low SMD and low SMI were defined according to previously reported thresholds, while high IMAT was defined using population-specific cut-point analysis. SMI, SMD, and IMAT were also measured at the proximal thigh (PT) level and tested as continuous variables. Clinical morpho-functional parameters, baseline nutritional markers with a known or suspected impact on HNC treatment, clinical outcomes and sarcopenia were also collected. In multivariate analyses, adjusted by age, sex, stage, diabetes, body mass index (BMI), and weight loss, L3-SMI was not significantly associated with survival, while poor muscle quality was negatively associated with overall survival (OS) (HR = 1.88, 95% CI = 1.09–3.23, p = 0.022 and HR = 2.04, 95% CI = 1.27–3.27, p = 0.003, for low L3-SMD and high L3-IMAT, respectively), progression-free survival (PFS) (HR = 2.26, 95% CI = 1.39–3.66, p = 0.001 and HR = 1.97, 95% CI = 1.30–2.97, p = 0.001, for low L3-SMD and high L3-IMAT, respectively) and cancer-specific survival (CSS) (HR = 2.40, 95% CI = 1.28–4.51, p = 0.006 and HR = 1.81, 95% CI = 1.04–3.13, p = 0.034, for low L3-SMD and high L3-IMAT, respectively). Indices at the PT level, tested as continuous variables, showed that increasing PT-SMI and PT-SMD were significant protective factors for all survival outcomes (for OS: HR for one cm²/m² increase in PT-SMI 0.96; 95% CI = 0.94–0.98; p = 0.001 and HR for one HU increase in PT-SMD 0.90; 95% CI = 0.85–0.94; p < 0.001, respectively). PT-IMAT was a significant risk factor only in the case of CSS (HR for one cm² increase 1.02; 95% CI = 1.00–1.03; p = 0.046). In conclusion, pre-treatment low muscle quality is a strong prognostic indicator of death risk in patients affected by HNC and undergoing (chemo)radiotherapy with curative intent.
Purpose
Myosteatosis, which is associated with a variety of cardiometabolic illnesses, represents muscle quality, an important aspect of sarcopenia. A new laboratory marker for myosteatosis has been required to more readily identify it. We investigated whether serum gamma-glutamyl transferase (GGT) levels are associated with myosteatosis measured by computed tomography (CT).
Methods
The total abdominal muscle area (TAMA) of 13,452 subjects was measured at the L3 level with abdominal CT. TAMA was segmented into intramuscular adipose tissue and skeletal muscle area (SMA), which was further classified into normal attenuation muscle area (NAMA) and low attenuation muscle area (LAMA). The following variables were adopted as indicators of myosteatosis: SMA/body mass index (BMI), NAMA/BMI, LAMA/BMI, and NAMA/TAMA. Logistic regression analysis was used to examine the odds ratio (OR) of each GGT quartile for the highest quartile of myosteatosis indices in each sex.
Results
The mean age and serum GGT levels were 53.7 years and 32.8 IU/L (standard deviation [SD], 37.6), respectively, in men, and 53.2 years and 18.4 IU/L (SD, 19.8) in women. In both sexes, the ORs of all myosteatosis indices differed significantly between GGT quartiles. Indices of good- and poor-quality muscle were negatively and positively correlated with GGT levels, respectively.
Conclusion
Higher GGT levels were significantly associated with advanced myosteatosis defined by reliable CT indices. This result opens the possibility for using GGT as a cost-effective indicator of myosteatosis. Further prospective research on changes to GGT levels with myosteatosis alleviation will validate GGT as a monitoring marker.
Muscle mass decreases with age, leading to “sarcopenia, ” or low relative muscle mass, in elderly people. Sarcopenia is believed
to be associated with metabolic, physiologic, and functional impairments and disability. Methods of estimating the prevalence
of sarcopenia and its associated risks in elderly populations are lacking. Data from a population-based survey of 883 elderly
Hispanic and non-Hispanic white men and women living in New Mexico (the New Mexico Elder Health Survey, 1993–1995) were analyzed
to develop a method for estimating the prevalence of sarcopenia. An anthropometric equation for predicting appendicular skeletal
muscle mass was developed from a random subsample(n = 199) of participants and was extended to the total sample. Sarcopenia was defined as appendicular skeletal muscle mass
(kg)/height2 (m2) being less than two standard deviations below the mean of a young reference group. Prevalences increased from 13–24% in
persons under 70 years of age to >50% in persons over 80 years of age, and were slightly greater in Hispanics than in non-Hispanic
whites. Sarcopenia was significantly associated with self-reported physical disability in both men and women, independent
of ethnicity, age, morbidity, obesity, income, and health behaviors. This study provides some of the first estimates of the
extent of the public health problem posed by sarcopenia. Am J Epidemiol 1998; 147: 755–63.
Muscle dysfunction and associated mobility impairment, common among the frail elderly, increase the risk of falls, fractures, and functional dependency. We sought to characterize the muscle weakness of the very old and its reversibility through strength training. Ten frail, institutionalized volunteers aged 90 ± 1 years undertook 8 weeks of high-intensity resistance training. Initially, quadriceps strength was correlated negatively with walking time (r= -.745). Fat-free mass (r=.732) and regional muscle mass (r=.752) were correlated positively with muscle strength. Strength gains averaged 174% ±31% (mean ± SEM) in the 9 subjects who completed training. Midthigh muscle area increased 9.0%± 4.5%. Mean tandem gait speed improved 48% after training. We conclude that high-resistance weight training leads to significant gains in muscle strength, size, and functional mobility among frail residents of nursing homes up to 96 years of age.
(JAMA. 1990;263:3029-3034)
The ability to distinguish between intra-abdominal and subcutaneous abdominal fat may be important in epidemiologic and clinical research. In this study anthropometric measurements were taken from 71 men and 34 women presenting for routine computed tomography (CT). Areas of abdominal fat were calculated from CT scans made at the level of the L4 vertebra. The amounts of intra-abdominal and subcutaneous abdominal fat could be accurately predicted from several circumferences, skinfold measurements, body mass index, and age (R2 ranged from 0.79 to 0.84). In addition, it was found that the area of intra-abdominal fat on the CT scan was related to the waist:hip circumference ratio (r = 0.75 in men, r = 0.55 in women) and to the waist:thigh circumference ratio (r = 0.55 in men, r = 0.70 in women). The correlations of the circumference ratios with the areas of subcutaneous fat were invariably lower.
A short battery of physical performance tests was used to assess lower extremity function in more than 5,000 persons age 71 years and older in three communities.
Balance, gait, strength, and endurance were evaluated by examining ability to stand with the feet together in the side-by-side, semi-tandem, and tandem positions, time to walk 8 feet, and time to rise from a chair and return to the seated position 5 times.
A wide distribution of performance was observed for each test. Each test and a summary performance scale, created by summing categorical rankings of performance on each test, were strongly associated with self-report of disability. Both self-report items and performance tests were independent predictors of short-term mortality and nursing home admission in multivariate analyses. However, evidence is presented that the performance tests provide information not available from self-report items. Of particular importance is the finding that in those at the high end of the functional spectrum, who reported almost no disability, the performance test scores distinguished a gradient of risk for mortality and nursing home admission. Additionally, within subgroups with identical self-report profiles, there were systematic differences in physical performance related to age and sex.
This study provides evidence that performance measures can validly characterize older persons across a broad spectrum of lower extremity function. Performance and self-report measures may complement each other in providing useful information about functional status.
Body mass index (BMI), % body fat, and the fat:lean ratio are ratios frequently used as obesity indices. Ratios are based on an assumption that the regression between the numerator (e.g. fat mass) and the denominator (e.g. body mass) has a zero-intercept. As shown in the companion paper, non-zero intercepts cause several problems when ratios are used to adjust data and analysis of covariance (ANCOVA) is frequently the preferred statistical tool. The purpose of this paper is to examine whether BMI, % body fat and the fat:lean ratio meet the necessary criteria for suitable obesity indices using gender comparisons as an example.
In 720 healthy men and women, BMI was higher in men (24.9 +/- 3.3 vs 23.4 +/- 3.2 kg/m2, P < 0.001), but fat mass, % fat and the fat:lean ratio were higher in women (14.8 +/- 8.4 vs 19.1 +/- 8.1 kg fat; 18.6 +/- 8.7 vs 29.9 +/- 9.7% body fat; 0.24 +/- 0.14 vs 0.46 +/- 0.20 for the fat:lean ratio; P < 0.001). Body mass (BM) was correlated with height2 in men (r = 0.40) and women (r = 0.36) with equivalent regression slopes (17.1 +/- 1.9 vs 15.6 +/- 2.3 kg per m2 in women), but the intercepts were different from zero (24.1 kg in men, 20.7 kg in women). When BM was adjusted for height2 using ANCOVA, men remained significantly heavier than women (74.4 +/- 11.0 vs 68.8 +/- 11.6 kg; P < 0.001). Fat mass (FM) was significantly correlated with BM in males (r = 0.64) and females (r = 0.78) but the regression slopes were different (0.49 +/- 0.03 vs 0.71 +/- 0.03 kg of fat per kg body mass in females; P < 0.05) and the intercepts were different from zero (-23.2 +/- 2.2 kg in males; -24.8 +/- 2.1 kg in females). FM adjusted for BM was significantly higher in women (11.7 vs 25.6 kg). FM was inversely correlated with fat free mass (FFM) in males (r = -0.17) and females (r = -0.20), with similar regression slopes (-0.16 +/- 0.05 vs -0.26 +/- 0.08 kg of FM per kg of FFM in women) and the intercepts were significantly different from zero (24.8 +/- 3.0 kg in males; 30.7 +/- 3.6 kg in females). When FM was adjusted for FFM, there was no significant difference between men (16.3 kg) and women (17.0 kg).
It is concluded that: (a) the presence of significant intercepts does not support the use of ratios as obesity indices and regression based models should be considered; and, (b) the direction and magnitude of the difference in obesity index between men and women changes with different normalization approaches.
Low muscle mass has been assumed to be associated with disability, but no studies confirming this association have been published. High body weight and high body mass index, both rough indicators of body fatness, have been shown to increase the risk for disability; however, the specific role of body fatness has not been studied.
The relations of skeletal muscle mass and percent body fat with self-reported physical disability were studied in 753 men and women aged 72 to 95 years. Cross-sectional data from biennial examination 22 (1992-1993) of the Framingham Heart Study were used. Body composition was assessed by dual-energy x-ray absorptiometry. Disability was scored as any versus none on a 9-item questionnaire.
Total body and lower extremity muscle mass were not associated with disability in either men or women. However, a strong positive association between percent body fat and disability was observed. The odds ratio for disability in those in the highest tertile of body fatness was 2.69 (95% confidence interval 1.45-5.00) for women and 3.08 (1.22-7.81) for men compared to those in the lowest tertile. The increased risk could not be explained by age, education, physical activity, smoking, alcohol use, estrogen use (women only), muscle mass, and health status. Analyses restricting disability to mobility items gave similar results.
In contrast to current assumptions, low skeletal muscle mass was not associated with self-reported physical disability. Persons with a high percent body fat had high levels of disability. Because it cannot be ruled out that persons with low skeletal muscle mass dropped out earlier in the study, prospective studies are needed to further assess the relationship between body composition and physical disability.
Weight loss (WL) decreases regional depots of adipose tissue and improves insulin sensitivity, two parameters that correlate before WL. To examine the potential relation of WL-induced change in regional adiposity to improvement in insulin sensitivity, 32 obese sedentary women and men completed a 4-month WL program and had repeat determinations of body composition (dual-energy X-ray absorptiometry and computed tomography) and insulin sensitivity (euglycemic insulin infusion). There were 15 lean men and women who served as control subjects. VO2max was unaltered with WL (39.2 +/- 0.8 vs. 39.8 +/- 1.1 ml x fat-free mass [FFM](-1) x min(-1)). The WL intervention achieved significant decreases in weight (100.2 +/- 2.6 to 85.5 +/- 2.1 kg), BMI (34.3 +/- 0.6 to 29.3 +/- 0.6 kg/m2), total fat mass (FM) (36.9 +/- 1.5 to 26.1 +/- 1.3 kg), percent body fat (37.7 +/- 1.3 to 31.0 +/- 1.5%), and FFM (59.2 +/- 2.3 to 55.8 +/- 2.0 kg). Abdominal subcutaneous and visceral adipose tissue (SAT and VAT) were reduced (494 +/- 19 to 357 +/- 18 cm2 and 157 +/- 12 to 96 +/- 7 cm2, respectively). Cross-sectional area of low-density muscle (LDM) at the mid-thigh decreased from 67 +/- 5 to 55 +/- 4 cm2 after WL. Insulin sensitivity improved from 5.9 +/- 0.4 to 7.3 +/- 0.5 mg x FFM(-1) x min(-1) with WL. Rates of insulin-stimulated nonoxidative glucose disposal accounted for the majority of this improvement (3.00 +/- 0.3 to 4.3 +/- 0.4 mg x FFM(-1) x min(-1)). Serum leptin, triglycerides, cholesterol, and insulin all decreased after WL (P < 0.01). After WL, insulin sensitivity continued to correlate with generalized and regional adiposity but, with the exception of the percent decrease in VAT, the magnitude of improvement in insulin sensitivity was not predicted by the various changes in body composition. These interventional weight loss data underscore the potential importance of visceral adiposity in relation to insulin resistance and otherwise suggest that above a certain threshold of weight loss, improvement in insulin sensitivity does not bear a linear relationship to the magnitude of weight loss.
Insulin resistance plays an important role in the pathogenesis of type 2 diabetes; however, the multiple mechanisms causing insulin resistance are not yet fully understood. The aim of this study was to explore the possible contribution of intramyocellular lipid content in the pathogenesis of skeletal muscle insulin resistance. We compared insulin-resistant and insulin-sensitive subjects. To meet stringent matching criteria for other known confounders of insulin resistance, these individuals were selected from an extensively metabolically characterized group of 280 first-degree relatives of type 2 diabetic subjects. Some 13 lean insulin-resistant and 13 lean insulin-sensitive subjects were matched for sex, age, BMI, percent body fat, physical fitness, and waist-to-hip ratio. Insulin sensitivity was determined by the hyperinsulinemic-euglycemic clamp method (for insulin-resistant subjects, glucose metabolic clearance rate [MCR] was 5.77+/-0.28 ml x kg(-1) x min(-1) [mean +/- SE]; for insulin-sensitive subjects, MCR was 10.15+/-0.7 ml x kg(-1) x min(-1); P<0.002). Proton magnetic resonance spectroscopy (MRS) was used to measure intramyocellular lipid content (IMCL) in both groups. MRS studies demonstrated that in soleus muscle, IMCL was increased by 84% (11.8+/-1.6 vs. 6.4+/-0.59 arbitrary units; P = 0.008 ), and in tibialis anterior muscle, IMCL was increased by 57% (3.26+/-0.36 vs. 2.08+/-0.3 arbitrary units; P = 0.017) in the insulin-resistant offspring, whereas the extramyocellular lipid content and total muscle lipid content were not statistically different between the two groups. These data demonstrate that in these well-matched groups of lean subjects, IMCL is increased in insulin-resistant offspring of type 2 diabetic subjects when compared with an insulin-sensitive group matched for age, BMI, body fat distribution, percent body fat, and degree of physical fitness. These results indicate that increased IMCL represents an early abnormality in the pathogenesis of insulin resistance and suggest that increased IMCL may contribute to the defective glucose uptake in skeletal muscle in insulin-resistant subjects.
The present study examines age-related changes in skeletal muscle size and function after 12 yr. Twelve healthy sedentary men were studied in 1985-86 (T1) and nine (initial mean age 65.4 +/- 4.2 yr) were reevaluated in 1997-98 (T2). Isokinetic muscle strength of the knee and elbow extensors and flexors showed losses (P < 0.05) ranging from 20 to 30% at slow and fast angular velocities. Computerized tomography (n = 7) showed reductions (P < 0.05) in the cross-sectional area (CSA) of the thigh (12.5%), all thigh muscles (14.7%), quadriceps femoris muscle (16.1%), and flexor muscles (14. 9%). Analysis of covariance showed that strength at T1 and changes in CSA were independent predictors of strength at T2. Muscle biopsies taken from vastus lateralis muscles (n = 6) showed a reduction in percentage of type I fibers (T1 = 60% vs. T2 = 42%) with no change in mean area in either fiber type. The capillary-to-fiber ratio was significantly lower at T2 (1.39 vs. 1. 08; P = 0.043). Our observations suggest that a quantitative loss in muscle CSA is a major contributor to the decrease in muscle strength seen with advancing age and, together with muscle strength at T1, accounts for 90% of the variability in strength at T2.
Low muscle strength is associated with poorer physical function, but limited empirical evidence is available to prove the relationship between muscle mass and physical function. We tested the hypothesis that persons with lower muscle mass or muscle strength have poorer lower-extremity performance (LEP).
A cross-sectional, population-based study.
A cohort of 449 men and women aged 65 years and older living in Amsterdam and its surroundings participating in the second examination (1995-1996) of the Longitudinal Aging Study Amsterdam.
Leg skeletal muscle mass was measured using dual-energy X-ray absorptiometry (DXA). Grip strength was used as an indicator of muscle strength. Timed functional performance tests, including walking and repeated chair stands, were used to assess LEP.
After adjustment for body height and age, leg muscle mass was positively associated with LEP in men (regression coefficient 0.178 [95% confidence interval 0.013-0.343], P = .035). In women an inverse association was observed, which became positive after additional adjustment for body mass index (BMI) (0.202 [-0.001-0.405], P = .052). Grip strength was positively associated with LEP in men and women. After additional adjustment for behavioral, physiological, and psychological variables, the associations between leg muscle mass and LEP disappeared, whereas grip strength remained to be independently associated with LEP in men (0.079 [0.042-0.116], P = .0001), with a tendency in women (0.046 [-0.009-0.101], P = .11). Results were similar when quartiles of leg muscle mass or grip strength were used.
These results suggest that low muscle strength, but not low muscle mass, is associated with poor physical function in older men and women. However, prospective studies are needed to investigate the association between loss of muscle mass and physical function.
To estimate the prevalence of physical disability associated with diabetes among U.S. adults > or =60 years of age.
We analyzed data from a nationally representative sample of 6,588 community-dwelling men and women > or =60 years of age who participated in the Third National Health and Nutrition Examination Survey. Diabetes and comorbidities (coronary heart disease, intermittent claudication, stroke, arthritis, and visual impairment) were assessed by questionnaire. Physical disability was assessed by self-reported ability to walk one-fourth of a mile, climb 10 steps, and do housework. Walking speed, lower-extremity function, and balance were assessed using physical performance tests.
Among subjects > or =60 years of age with diabetes, 32% of women and 15% of men reported an inability to walk one-fourth of a mile, climb stairs, or do housework compared with 14% of women and 8% of men without diabetes. Diabetes was associated with a 2- to 3-fold increased odds of not being able to do each task among both men and women and up to a 3.6-fold increased risk of not being able to do all 3 tasks. Among women, diabetes was also associated with slower walking speed, inferior lower-extremity function, decreased balance, and an increased risk of falling. Of the >5 million U.S. adults > or =60 years of age with diabetes, 1.2 million are unable to do major physical tasks.
Diabetes is associated with a major burden of physical disability in older U.S. adults, and these disabilities are likely to substantially impair their quality of life.
Loss of lean body and muscle mass characterizes the acquired immunodeficiency syndrome (AIDS) wasting syndrome (AWS). Testosterone and exercise increase muscle mass in men with AWS, with unclear effects on muscle composition. We examined muscle composition in 54 eugonadal men with AWS who were randomized to 1) testosterone (200 mg im weekly) or placebo and simultaneously to 2) resistance training or no training in a 2 x 2 factorial design. At baseline and after 12 wk, we performed assessments of whole body composition by dual-energy X-ray absorptiometry and single-slice computed tomography for midthigh cross-sectional area and muscle composition. Leaner muscle has greater attenuation. Baseline muscle attenuation correlated inversely with whole body fat mass (r = -0.52, P = 0.0001). This relationship persisted in a model including age, body mass index, testosterone level, viral load, lean body mass, and thigh muscle cross-sectional area (P = 0.02). Testosterone (P = 0.03) and training (P = 0.03) increased muscle attenuation. These data demonstrate that thigh muscle attenuation by computed tomography varies inversely with whole body fat and increases with testosterone and training. Anabolic therapy in these patients increases muscle leanness.
The association of muscle mass and muscle strength with lower-extremity performance, as measured by timed repeated chair stands, was investigated using preliminary data from 3,075 Black and White participants (70–79 years old) in the Health, Aging, and Body Composition Study. Leg muscle mass (LM) was measured by dual-energy X-ray absorptiometry (Hologic QDR 4500). The maximal isokinetic torque of the leg extensors (LS) was measured at 60°/s using a Kin-Com isokinetic dynamometer. Men were stronger, had greater LM, and better performance than women. As expected, low LS was associated with poorer performance after adjusting for race, study site, and body fat. Low LM was associated with poorer performance in men and women, with a potential threshold effect in women only. When LS and LM were modeled simultaneously, only LS remained independently associated with performance. In conclusion, muscle strength, but not muscle mass, is independently associated with lower-extremity performance.
Although loss of muscle mass is considered a cause of diminished muscle strength with aging, little is known regarding whether composition of aging muscle affects strength. The skeletal muscle attenuation coefficient, as determined by computed tomography, is a noninvasive measure of muscle density, and lower values reflect increased muscle lipid content. This investigation examined the hypothesis that lower values for muscle attenuation are associated with lower voluntary isokinetic knee extensor strength at 60 degrees/s in 2,627 men and women aged 70-79 yr participating in baseline studies of the Health ABC Study, a longitudinal study of health, aging, and body composition. Strength was higher in men than in women (132.3 +/- 34.5 vs. 81.4 +/- 22.0 N x m, P < 0.01). Men had greater muscle attenuation values (37.3 +/- 6.5 vs. 34.7 +/- 7.0 Hounsfield units) and muscle cross-sectional area (CSA) at the midthigh than women (132.7 +/- 22.4 vs. 93.3 +/- 17.5 cm(2), P < 0.01 for both). The strength per muscle CSA (specific force) was also higher in men (1.00 +/- 0.21 vs. 0.88 +/- 0.21 N x m x cm(-2)). The attenuation coefficient was significantly lower for hamstrings than for quadriceps (28.7 +/- 8.7 vs. 41.1 +/- 6.9 Hounsfield units, P < 0.01). Midthigh muscle attenuation values were lowest (P < 0.01) in the eldest men and women and were negatively associated with total body fat (r = -0.53, P < 0.01). Higher muscle attenuation values were also associated with greater specific force production (r = 0.26, P < 0.01). Multivariate regression analysis revealed that the attenuation coefficient of muscle was independently associated with muscle strength after adjustment for muscle CSA and midthigh adipose tissue in men and women. These results demonstrate that the attenuation values of muscle on computed tomography in older persons can account for differences in muscle strength not attributed to muscle quantity.
Computed tomography (CT) was used to quantify components of the thigh in young (n = 13) and elderly (n = 11) men. Cross-sectional areas (CSA) of the total limb, total muscle plus bone, quadriceps compartment, hamstring compartment and bone were measured at each of five scan sites along the length of the thigh. Non-muscle tissue (NMT) areas within the muscle compartments were measured using changes in density based on Hounsfield units. Skin plus subcutaneous fat areas and quadriceps and hamstring lean muscle areas were calculated by subtraction. Geometric formulae were used to calculate related volumes for each thigh component. Volumes were also predicted from regression equations employing thigh length and component CSA from single mid-limb CT scans. The results showed that while total thigh CSA was not different in elderly men, they had significantly smaller total muscle plus bone (13.0%), and quadriceps (26.4%), and hamstring (17.9%) muscle areas. The elderly men also had significantly greater CSA for skin plus subcutaneous fat (37.6%), and for NMT in the quadriceps (59.4%) and hamstring (127.3%) muscle compartments. These results suggest that comparisons of relative leg muscle strength between young and elderly men may be misleading due to the decrease in actual muscle tissue associated with ageing. Appropriate quantification of muscle size and CSA must be carried out before such comparisons can be meaningful.
1. A method is described enabling the determination of fat, water, electrolytes, protein, DNA, RNA and total creatine in a single sample of human muscle obtained by the percutaneous needle-biopsy technique. The amino acid content can also be analysed in the same muscle sample.
2. Fifty healthy subjects were studied: 29 between 19 and 40 years of age, 11 between 41 and 60 years of age, and 10 between 61 and 85 years of age. The two groups aged less than 60 years showed only marginal differences in muscle composition, whereas the highest age group showed increases in muscle fat content in relation to tissue weight and decreases in alkali-soluble protein content in relation to both tissue weight and tissue DNA content. Also, potassium, magnesium, total creatine and RNA contents were decreased in this age group when related to tissue DNA content. When alkali-soluble protein was used as a reference base, only magnesium content was decreased.
3. A comparison was also made between female (n = 23) and male (n = 18) subjects in the age groups below 60 years. Differences observed included a higher fat content in female muscle, and an increase in total creatine content in relation to tissue weight. The alkali-soluble protein content was lower per muscle cell in the females when calculated on the basis of DNA content.
4. The results show that in the assessment of muscle constituents, age and sex must be taken into account.
Obesity is associated with increased lean mass but its effects on lean-tissue density are less clear. To examine the effects of obesity and non-insulin-dependent diabetes mellitus (NIDDM) on lean-tissue composition and density, cross-sectional computed tomography (CT) scans of the midthigh were obtained in 20 men of various weights. Obesity was associated with increases in thigh-adipose (r = 0.75) and lean-tissue volumes (r = 0.52) and with reduced density of lean tissue (r = -0.73). The increased lean tissue in obesity was due to a nonadipose tissue component with a density below the normal range of muscle, an effect compounded by NIDDM, whereas normal-density muscle volume was unchanged.
Computed tomography scans were taken of 21 middle-aged men (M age 46.3 years) and 20 older men (M age 69.4 years) to measure
differences in body composition with age. Overall, the older men weighed 8.2 kg less than the middle-aged men, and this difference
was primarily the result of their having less lean tissue. Although fat mass was only slightly less in older men, there were
clear distributional differences in fat between the age groups. Total abdomen fat area was similar in both groups, although
the subcutaneous portion of the abdomen fat was less in the older men, and they had correspondingly greater intra-abdominal
fat. Muscle areas of the leg and arm were significantly less in the older men, as were all lean tissues of the abdomen and
chest. Analysis of fat accumulation between muscles of the abdomen and leg indicated fat infiltration into lean tissue in
the older men. Causes of this apparent fat redistribution and lean body mass decline with age are presently unknown.
The accuracy of CT diagnosis of increased fat deposition in the liver was assessed in 11 alcoholic patients with suspected fatty liver. Single-energy CT attenuation values were compared with histological assessment of fatty liver and chemical analysis of liver triglyceride concentrations, obtained from liver biopsy specimens. Measured attenuation values showed an inverse correlation with the degree of fatty change assessed histologically (r =--0.90; p Less Than 0.0001) and with that assessed chemically (r=--0.57; p Less Than 0.05). CT scanning may provide a useful non-invasive method for detecting and following patients with fatty liver, particularly when liver biopsy is contraindicated.
Knee extension strength, walking speed, quadriceps muscle mass and composition of the muscle compartment were studied in 66 to 85-year-old female athletes and controls. Maximal voluntary knee extension force, force/body mass, extension torque, torque/body mass and walking speed were higher for the athletes than the controls. A muscle index indicating intramuscular fat and connective tissue measured using ultrasonography was lower for the athletes than the controls. There were no differences between the study groups in knee extension force related either to cross-sectional area (CSA) or lean tissue area (CSAL) of the quadriceps. Within the subgroups, there was no significant correlation between knee extension torque and CSA or CSAL of the same muscle. In the athletes high knee extension torque/body mass was related to a low muscle index and high walking speed to a low relative proportion of fat in the muscle. The muscle index was lower the more kilometers trained during the preceding year. In the controls high knee extension torque/body mass and high walking speed were related to a low relative proportion of fat. Knee extension torque and walking speed were higher the more kilometers walked during the preceding year. The results indicate that elderly female athletes have superior muscle performance compared to their age-peers. Performance in a maximal isometric strength test in elderly women is not clearly related to muscle mass. However, to some extent it is related to the composition of the same muscle, especially the degree to which fat is infiltrated into the muscle.
A coding scheme is presented for classifying physical activity by rate of energy expenditure, i.e., by intensity. Energy cost was established by a review of published and unpublished data. This coding scheme employs five digits that classify activity by purpose (i.e., sports, occupation, self-care), the specific type of activity, and its intensity as the ratio of work metabolic rate to resting metabolic rate (METs). Energy expenditure in kilocalories or kilocalories per kilogram body weight can be estimated for all activities, specific activities, or activity types. General use of this coding system would enhance the comparability of results across studies using self reports of physical activity.
The use of ratios to adjust data (i.e. 'index' variables) is common in obesity and related research. The rationale for the use of ratios often seems to be the desire to control or eliminate the influence of the variable in the denominator. The purpose of this paper is to gain a greater appreciation of the statistical assumptions underlying ratios and their impact on data interpretation.
We demonstrate the limitations of the indiscriminant use of ratios to adjust data. Specifically, we show that: (1) given linearity, a zero intercept between the numerator and denominator are necessary and sufficient conditions for a ratio to remove the confounding effects of the denominator; (2) seemingly minor departures from a zero intercept can have major consequences on the ratio's ability to control for the denominator; (3) the ratio of two normally distributed variables cannot be normally distributed, and this may violate the assumptions of subsequent parametric statistical analyses; (4) the use of ratios affects the error distribution of the data which may also violate the assumptions of subsequent parametric statistical analyses; (5) the use of ratios cannot easily take nonlinear effects between the numerator and denominator into account; (6) the use of ratios can introduce spurious correlations among the ratios and other variables; (7) the use of ratios can create interpretive difficulties. We also clarify that the mean of ratios is not necessarily equivalent to the ratio of the means of the numerator and denominator. Finally, we present and discuss formulae for the reliability of ratios and residuals.
Because of the above issues, we question the indiscriminant use of ratios and advocate that investigators consider regression-based approaches as alternatives.
Pencil-beam dual-energy X-ray absorptiometers (DXA) are being replaced with instruments that rely solely on fan-beam technology. However, information has been lacking regarding the translation of bone mineral and body composition data between the two devices. We have compared total body scans using pencil-beam (Hologic QDR-2000W) and fan-beam (Hologic QDR-4500A) instruments for 33 children (ages 3-18 years) and 14 adults. Bone mineral content (BMC), bone mineral density (BMD), fat, lean, and body fatness (%fat) values were highly correlated (r2 = 0.984-0.998) between the two DXA instruments. The mean differences between the paired measurements were: deltaBMC = 7.5 +/- 73.6 g, deltaBMD = 0.0074 +/- 0.0252 g/cm2, delta lean = 1.05 +/- 1.8 kg, delta fat = -0.77 +/- 1.7 kg, and delta%fat = -0.94% +/- 2.5%. The BMC and BMD values were not statistically different, whereas the differences for the body composition values were significant (p < 0.02-0.005). Regression equations are provided for conversion of bone and body composition data between pencil-beam and fan-beam values for the whole body. To test the performance of these equations for a second group (23 subjects), predicted values were compared with the measured data obtained using the fan-beam instrument. The mean differences were -1.0% to 1.4%, except for body fat mass, where the difference was 6.4%. For cross-sectional studies, the two DXA technologies can be considered equivalent after using the translational equations provided. For longitudinal studies in which small changes in body composition for the individual are to be detected, we recommend that the same DXA instrument be used whenever possible. For example, transition from a pencil-beam to a fan-beam instrument could, in extreme cases, result in differences as large as 19% for the estimate of body fat mass.
The effects of chromium picolinate (CrPic) supplementation and resistance training (RT) on skeletal muscle size, strength, and power and whole body composition were examined in 18 men (age range 56-69 yr). The men were randomly assigned (double-blind) to groups (n = 9) that consumed either 17.8 micromol Cr/day (924 microg Cr/day) as CrPic or a low-Cr placebo for 12 wk while participating twice weekly in a high-intensity RT program. CrPic increased urinary Cr excretion approximately 50-fold (P < 0.001). RT-induced increases in muscle strength (P < 0.001) were not enhanced by CrPic. Arm-pull muscle power increased with RT at 20% (P = 0.016) but not at 40, 60, or 80% of the one repetition maximum, independent of CrPic. Knee-extension muscle power increased with RT at 20, 40, and 60% (P < 0.001) but not at 80% of one repetition maximum, and the placebo group gained more muscle power than did the CrPic group (RT by supplemental interaction, P < 0.05). Fat-free mass (P < 0.001), whole body muscle mass (P < 0.001), and vastus lateralis type II fiber area (P < 0.05) increased with RT in these body-weight-stable men, independent of CrPic. In conclusion, high-dose CrPic supplementation did not enhance muscle size, strength, or power development or lean body mass accretion in older men during a RT program, which had significant, independent effects on these measurements.
To determine if fat deposition within mid-thigh muscle, represented by low density lean tissue density, is associated with age, low physical fitness, hyperleptinemia, hyperinsulinemia and dyslipidemia in women.
Seventy-two women aged 18-69y with a wide range of total body fat (10-55%) and maximal aerobic capacity (VO2max: 17-61 ml/kg(-1)/min(-1)).
Mid-thigh muscle, mid-thigh fat, low density lean tissue, intra-abdominal adipose tissue (IAAT) and subcutaneous abdominal fat (by computed tomography, CT), fat mass (FM) and fat-free mass (FFM) (by dual energy x-ray absorptiometry, DEXA), plasma insulin and leptin (by radioimmunoassay, RIA) and lipoprotein lipid profiles (by enzymatic methods).
VO2max declined with age (r=-0.59, P<0.0001) while IAAT and subcutaneous abdominal fat increased with age (r=0.68, r=0.57, r=0.63, P<0.0001). Mid-thigh low density lean tissue correlated with age (r=0.52), VO2max (r=-0.56), FFM (r=0.35), fat mass (r=0.68), IAAT (r=0.66) and subcutaneous abdominal fat (r=0.67, all P<0.005). Mid-thigh low density lean tissue also correlated with fasting plasma leptin, insulin, triacylglycerol (TG), total cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C) levels (r=0.44, 0.34, 0.41, 0.50, 0.53, respectively, all P<0.005), but not after controlling for body fat and age. Subcutaneous abdominal fat, IAAT, FFM and age were independent predictors of low density lean tissue (P<0.05).
Mid-thigh low density lean tissue is directly related to age and adiposity. Furthermore, it appears that fat accretion in skeletal muscle adversely influences plasma insulin and lipoprotein metabolism in women, but not independently of total adiposity and age.
The aim of the study was to examine the accuracy of fan-beam dual-energy X-ray absorptiometry (DEXA) for measuring total body fat-free mass (FFM) and leg muscle mass (MM) in elderly persons. Participants were 60 men and women aged 70-79 yr and with a body mass index of 17.5-39.8 kg/m(2). FFM and MM at four leg regions were measured by using DEXA (Hologic 4500A, v8.21). A four-compartment body composition model (4C) and multislice computed tomography (CT) of the legs were used as the criterion methods for FFM and MM, respectively. FFM by DEXA was positively associated with FFM by 4C (R(2) = 0.98, SE of estimate = 1.6 kg). FFM by DEXA was higher [53.5 +/- 12.0 (SD) kg] than FFM by 4C (51.6 +/- 11.9 kg; P < 0.001). No association was observed between the difference and the mean of the two methods. MM by DEXA was positively associated with CT at all four leg regions (R(2) = 0.86-0.96). MM by DEXA was higher than by CT in three regions. The results of this study suggest that fan-beam DEXA offers considerable promise for the measurement of total body FFM and leg MM in elderly persons.
The association of muscle mass and muscle strength with lower-extremity performance, as measured by timed repeated chair stands, was investigated using preliminary data from 3,075 Black and White participants (70-79 years old) in the Health, Aging, and Body Composition Study. Leg muscle mass (LM) was measured by dual-energy X-ray absorptiometry (Hologic QDR 4500). The maximal isokinetic torque of the leg extensors (LS) was measured at 60 degrees/s using a Kin-Com isokinetic dynamometer. Men were stronger, had greater LM, and better performance than women. As expected, low LS was associated with poorer performance after adjusting for race, study site, and body fat. Low LM was associated with poorer performance in men and women, with a potential threshold effect in women only. When LS and LM were modeled simultaneously, only LS remained independently associated with performance. In conclusion, muscle strength, but not muscle mass, is independently associated with lower-extremity performance.
The accuracy of total body fat mass and leg fat mass measurements by fan-beam dual-energy X-ray absorptiometry (DEXA) was assessed in 60 healthy elderly subjects (aged 70-79 yr). Total fat and leg fat mass at four leg regions (total leg, thigh, midthigh, and calf) were measured with the QDR 4500A (Hologic, Waltham, MA). The four-compartment model and multislice computed tomography scans were selected as criterion methods for total fat and leg fat mass, respectively. Total fat mass from DEXA was positively associated with fat mass from the four-compartment model with a standard error of the estimate ranging from 1.4 to 1.6 kg. DEXA fan-beam tended to overestimate fat mass for total leg and total thigh fat mass, whereas only marginal differences in fat mass measurements at the midthigh and calf were demonstrated (</=0.08 kg, P < 0.0005). Although there were significant differences between DEXA fan beam and the criterion methods, these differences were of small magnitude, suggesting that DEXA is an accurate method for measurement of fat mass for the elderly.
The purpose of this investigation was to validate that in vivo measurement of skeletal muscle attenuation (MA) with computed tomography (CT) is associated with muscle lipid content. Single-slice CT scans performed on phantoms of varying lipid concentrations revealed good concordance between attenuation and lipid concentration (r(2) = 0.995); increasing the phantom's lipid concentration by 1 g/100 ml decreased its attenuation by approximately 1 Hounsfield unit (HU). The test-retest coefficient of variation for two CT scans performed in six volunteers was 0.51% for the midthigh and 0.85% for the midcalf, indicating that the methodological variability is low. Lean subjects had significantly higher (P < 0.01) MA values (49.2 +/- 2.8 HU) than did obese nondiabetic (39.3 +/- 7.5 HU) and obese Type 2 diabetic (33.9 +/- 4. 1 HU) subjects, whereas obese Type 2 diabetic subjects had lower MA values that were not different from obese nondiabetic subjects. There was also good concordance between MA in midthigh and midcalf (r = 0.60, P < 0.01), psoas (r = 0.65, P < 0.01), and erector spinae (r = 0.77, P < 0.01) in subsets of volunteers. In 45 men and women who ranged from lean to obese (body mass index = 18.5 to 35.9 kg/m(2)), including 10 patients with Type 2 diabetes mellitus, reduced MA was associated with increased muscle fiber lipid content determined with histological oil red O staining (P = -0.43, P < 0. 01). In a subset of these volunteers (n = 19), triglyceride content in percutaneous biopsy specimens from vastus lateralis was also associated with MA (r = -0.58, P = 0.019). We conclude that the attenuation of skeletal muscle in vivo determined by CT is related to its lipid content and that this noninvasive method may provide additional information regarding the association between muscle composition and muscle function.
Skeletal muscle loss or sarcopenia in aging has been suggested in cross-sectional studies but has not been shown in elderly subjects using appropriate measurement techniques combined with a longitudinal study design. Longitudinal skeletal muscle mass changes after age 60 yr were investigated in independently living, healthy men (n = 24) and women (n = 54; mean age 73 yr) with a mean +/- SD follow-up time of 4.7 +/- 2.3 yr. Measurements included regional skeletal muscle mass, four additional lean components (fat-free body mass, body cell mass, total body water, and bone mineral), and total body fat. Total appendicular skeletal muscle (TSM) mass decreased in men (-0.8 +/- 1.2 kg, P = 0.002), consisting of leg skeletal muscle (LSM) loss (-0.7 +/- 0.8 kg, P = 0.001) and a trend toward loss of arm skeletal muscle (ASM; -0.2 +/- 0.4 kg, P = 0.06). In women, TSM mass decreased (-0.4 +/- 1.2 kg, P = 0.006) and consisted of LSM loss (-0.3 +/- 0.8 kg, P = 0.005) and a tendency for a loss of ASM (-0.1 +/- 0.6 kg, P = 0.20). Multiple regression modeling indicates greater rates of LSM loss in men. Body weight in men at follow-up did not change significantly (-0.5 +/- 3.0 kg, P = 0.44) and fat mass increased (+1.2 +/- 2.4 kg, P = 0.03). Body weight and fat mass in women were nonsignificantly reduced (-0.8 +/- 3.9 kg, P = 0.15 and -0.8 +/- 3.5 kg, P = 0.12). These observations suggest that sarcopenia is a progressive process, particularly in elderly men, and occurs even in healthy independently living older adults who may not manifest weight loss.
It has been suggested that nondisabled older persons with poor performance of lower extremity function are ideal targets for interventions of disability prevention. However, health-related factors associated with poor performance are largely unknown. Using data from a representative sample of nondisabled older persons, this study identifies the diseases and biological markers that characterize this group of the population.
A total of 3,381 persons aged 71 or older, interviewed and administered a battery of physical performance tests at the sixth annual follow-up of the Established Populations for Epidemiologic Studies of the Elderly (EPESE), who reported no need for help in walking 1/4 mile or climbing stairs.
Lower extremity performance was measured using a short battery of tests including assessment of standing balance, a timed 2.4-m walk, and timed test of rising 5 times from a chair. Chronic conditions were ascertained as self-report of a physician diagnosis. Data on previous hospitalizations were obtained from the Medicare database. Nonfasting blood samples were obtained and processed with standard methods.
In a multivariate analysis, older age, female gender, higher BMI, history of hip fracture and diabetes, one or more hospital admissions for acute infection in the last 3 years, lower levels of hemoglobin and albumin, and higher leukocytes and gamma-glutamyl transferase were all associated independently with poor performance.
Screening for older patients who are not disabled but have poor lower extremity performance selects a subgroup of the population with a high percentage of women, high prevalence of diabetes and hip fracture, and high levels of biological markers of inflammation. This group represents about 10% of the US population 70 to 90 years old. These findings should be considered in planning specifically tailored interventions for disability prevention in this subgroup.
Weight stability masks body composition changes in elderly men: Visceral fat increase and lean tissue loss.
- Gallagher
Gallagher D, Ruts E, Visser M et al. Weight stability masks body composi-tion changes in elderly men: Visceral fat increase and lean tissue loss. Am J Physiol 2000;279:E366–E375.
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