Figure 3 - uploaded by Borja Martínez-Téllez
Content may be subject to copyright.
Measures of skin temperature at the last five minutes of the first warm period as estimated with the equations used in the respective references. (A) Mean skin temperature: *P = 0.022: 14-ISO vs. 4-ISO; † P < 0.001: 8-ISO vs. Boon; # P = 0.001: 4-ISO vs. Boon; ‡ P = 0.021: Boon vs. PROFITH. (B) Proximal skin temperature: † P = 0.015: Krauchi vs. PROFITH; **P = 0.048: Krauchi vs. Schellen; § P = 0.011: Van Marken vs. PROFITH; ‡ P = 0.036: Van Marken vs. Schellen; # P = 0.014 Schellen vs. Boon; *P = 0.004: Boon vs. PROFITH. (C) Distal skin temperature: P = 0.222: Krauchi vs PROFITH. (D) Body temperature gradients: P = 0.931: Boon vs PROFITH. (E) Supraclavicular temperature gradients: (S: Supraclavicular; LC: Left Chest; RC: Right Chest; SB: Subclavicular); All P = 1.000. (F) Peripheral temperature gradient: All P = 1.000. Data are mean and standard error.
Source publication
Cold exposure is necessary to activate human brown adipose tissue (BAT), resulting in heat production. Skin temperature is an indirect measure to monitor the body’s reaction to cold. The aim of this research was to study whether the most used equations to estimate parameters of skin temperature in BAT-human studies measure the same values of temper...
Contexts in source publication
Context 1
... period I. Figure 3 shows the mean skin temperature (A), proximal skin temperature (B), distal skin temperature (C), body temperature gradient (D), supraclavicular temperature gradient (E), and temperature gra- dients as a proxy for upper (left and right arm) and lower (left and right leg) peripheral vasoconstrictions (F) in the last five minutes of warm period I as estimated with the equations used in literature (Table 1). ANOVA showed differences across mean skin temperature equations (overall P < 0.001, Fig. 3A). ...
Context 2
... temperature gradient (E), and temperature gra- dients as a proxy for upper (left and right arm) and lower (left and right leg) peripheral vasoconstrictions (F) in the last five minutes of warm period I as estimated with the equations used in literature (Table 1). ANOVA showed differences across mean skin temperature equations (overall P < 0.001, Fig. 3A). The post-hoc analy- sis showed significant differences in mean skin temperature using the equation reported by 4-ISO 41 compared with 14-ISO 41 (mean difference 1.35 °C; 95% confidence interval: 0.12 °C-2.57 °C; P = 0.022) and between the equation reported by Boon et al. 15 Similarly, significant differences were observed across ...
Context 3
... differences in mean skin temperature using the equation reported by 4-ISO 41 compared with 14-ISO 41 (mean difference 1.35 °C; 95% confidence interval: 0.12 °C-2.57 °C; P = 0.022) and between the equation reported by Boon et al. 15 Similarly, significant differences were observed across proximal skin temperature equations (overall P < 0.001, Fig. 3B). The post-hoc analysis revealed significant differences between the equation reported by Schellen et al. 32 compared to Boon et al. 15 (mean difference 1.03 °C; 95% confident interval: 0.13 °C-1.93 °C; P = 0.014), Kräuchi et al. 36 (0.90 °C; 0.01 °C-1.81 °C; P = 0.048), and van Marken Lichtenbelt et al. 26 (0.93 °C; −0.82 °C-1.84 °C; ...
Context 4
... were no significant differences between the equations used to estimate distal skin temperature (Fig. 3C), body (Fig. 3D), and supraclavicular ( Fig. 3E) and peripheral (Fig. 3F) temperature gradients (all P ≥ ...
Context 5
... were no significant differences between the equations used to estimate distal skin temperature (Fig. 3C), body (Fig. 3D), and supraclavicular ( Fig. 3E) and peripheral (Fig. 3F) temperature gradients (all P ≥ ...
Context 6
... were no significant differences between the equations used to estimate distal skin temperature (Fig. 3C), body (Fig. 3D), and supraclavicular ( Fig. 3E) and peripheral (Fig. 3F) temperature gradients (all P ≥ ...
Citations
... The supraclavicular skin temperature was measured at 1-minute intervals using wireless iButton temperature loggers (31) and through infrared thermographic (IRT) images (FLIR T450sc, FLIR systems Inc., Wilsonville, OR, USA) focused on the upper thorax/neck region at the start of the study visit and after cold exposure. Analysis of the data recorded by the iButton temperature loggers was analyzed using Temperatus software (http://profith.ugr.es/temperatus) ...
... Analysis of the data recorded by the iButton temperature loggers was analyzed using Temperatus software (http://profith.ugr.es/temperatus) (31), while the IRT images were processed via an open-source IRT toolbox software. Further details of the methods were described previously (12). ...
Objectives: Cold exposure is linked to cardiometabolic benefits. Cold activates brown adipose tissue (BAT), increases energy expenditure, and induces secretion of the hormones fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15). The cold-induced increase in energy expenditure exhibits a diurnal rhythm in men. Therefore, we aimed to investigate the effect of cold exposure on serum FGF21 and GDF15 levels in humans and whether cold-induced changes in FGF21 and GDF15 levels differ between morning and evening in males and females.
Method: In this randomized cross-over study, serum FGF21 and GDF15 levels were measured in healthy lean males (n=12) and females (n=12) before, during, and after 90 minutes of stable cold exposure in the morning (7:45am) and evening (7:45pm) with a one-day washout period in between.
Results: Cold exposure increased FGF21 levels in the evening compared to the morning both in males (+61% vs. -13%; P<0.001) and in females (+58% vs. +8%; P<0.001). In contrast, cold exposure did not significantly modify serum GDF15 levels, and no diurnal variation was found. Changes in FGF21 and GDF15 levels did not correlate with changes in cold-induced energy expenditure in the morning and evening.
Conclusion: Cold exposure increased serum FGF21 levels in the evening, but not in the morning, in both males and females. GDF15 levels were not affected by cold exposure. Thus, this study suggests that the timing of cold exposure may influence cold-induced changes in FGF21 levels but not GDF15 levels and seems to be independent of changes in energy expenditure.
... 42 Skin temperature was recorded at 1 min intervals and a mean value for every 5 min was calculated for each thermometer. We calculated the mean, 43 proximal, 44 distal, 43 peripheral gradient (forearm minus fingertip), 43 and supraclavicular temperature. 45 All analysis and calculations were performed using the Temperatus ® software (http://profith.ugr.es/temperatus) ...
... 42 Skin temperature was recorded at 1 min intervals and a mean value for every 5 min was calculated for each thermometer. We calculated the mean, 43 proximal, 44 distal, 43 peripheral gradient (forearm minus fingertip), 43 and supraclavicular temperature. 45 All analysis and calculations were performed using the Temperatus ® software (http://profith.ugr.es/temperatus) ...
... 42 Skin temperature was recorded at 1 min intervals and a mean value for every 5 min was calculated for each thermometer. We calculated the mean, 43 proximal, 44 distal, 43 peripheral gradient (forearm minus fingertip), 43 and supraclavicular temperature. 45 All analysis and calculations were performed using the Temperatus ® software (http://profith.ugr.es/temperatus) ...
Background There is a subset of individuals with overweight/obesity characterized by a lower risk of cardiometabolic complications, the so-called metabolically healthy overweight/obesity (MHOO) phenotype. Despite the relatively higher levels of subcutaneous adipose tissue and lower visceral adipose tissue observed in individuals with MHOO than individuals with metabolically unhealthy overweight/obesity (MUOO), little is known about the differences in brown adipose tissue (BAT).
... Sixteen resistance-trained men (age: 23 [SD]) with at least 2 years of RT experience in the squat exercise participated in this study. All the subjects were informed of the risks and benefits of the study and not to perform intense training at least 24 hours before testing. ...
... We measured the T sk using 8 iButtons (DS-1922 L, Thermochron; resolution: 0.0625°C, Maxim), which are valid and reliable devices to assess T sk in humans during exercise. 23,24 Immediately upon arrival, subjects were dressed in training shoes and underpants. The researchers dried out the subjects' skin to avoid sweat. ...
... The iButtons were attached to the skin with adhesive tape in the following anatomical positions: forehead, left chest, left forearm, left top of forefinger, right quadriceps, left hamstrings, right shinbone, and left gastrocnemius. 23 Subjects remained seated for 5 minutes before the beginning of the warm-up. We calculated the mean T sk as the average of T sk in all anatomical positions. ...
Purpose:
This study aimed to (1) evaluate the acute effects of different interrepetition rest full-squat protocols on countermovement jump (CMJ) height, velocity loss (VL), and skin temperature (Tsk) and (2) determine whether the VL, the changes in Tsk, or the individual strength level is associated with the change in CMJ height.
Methods:
Sixteen resistance-trained men randomly performed 3 squat protocols at maximal intended velocity with 60% of the 1-repetition maximum (sets × repetitions [interrepetition rest]): traditional (2 × 6 [0 s]), cluster 2 (2 × 6 [30 s every 2 repetitions]), and cluster 1 (1 × 12; [36 s every repetition]), plus a control session. CMJ height was assessed before and 2, 4, and 8 minutes after the protocols.
Results:
There was a significant main effect of protocol for the VL (F = 20.54, P < .001) and loss in mean power (F = 12.85, P < .001; traditional > cluster 2 > cluster 1). However, we found a comparable reduction of CMJ height after 8 minutes: traditional (-3.4% [4.2%]), cluster 2 (-5.3% [4.9%]), cluster 1 (-5.4% [2.9%]), and control (-4.2% [3.6%]). Overall, mean Tsk acutely decreased after all the protocols. Higher individual strength level (but not VL or the changes in Tsk) was associated with lower CMJ-height loss (P < .05).
Conclusions:
Although different interrepetition rest full-squat protocols may alter the loss in velocity and power, they result in a similar decrease in Tsk and CMJ height, which could be more influenced by individual strength level than VL or changes in Tsk.
... Then, these data were divided into blocks of 5 min, and their average was calculated, obtaining 12 mean values (one for each 5 min-block of the 60 min steady-state test). Finally, the overall mean [36], proximal [37], and distal skin temperatures were calculated using the Temperatus® software -see references [19,38] for further information. The validity and reliability of this system have been established for the assessment of skin temperature in humans [35,39]. ...
... The validity and reliability of this system have been established for the assessment of skin temperature in humans [35,39]. The equations used (see below) have been described elsewhere [38]. ...
Background:
Prior evidence suggests that capsinoids ingestion may increase resting energy expenditure (EE) and fat oxidation (FATox), yet whether they can modulate those parameters during exercise conditions remains poorly understood. We hypothesized that dihydrocapsiate (DHC) ingestion would increase EE and specifically FATox during an acute bout of aerobic exercise at FATmax intensity (the intensity that elicits maximal fat oxidation during exercise [MFO]) in men with overweight/obesity. Since FATmax and MFO during aerobic exercise appear to be indicators of metabolic flexibility, whether DHC has an impact on FATox in this type of population is of clinical interest.
Methods:
A total of 24 sedentary men (age = 40.2 ± 9.2 years-old; body mass index = 31.6 ± 4.5 kg/m2 [n = 11 overweight, n = 13 obese]) participated in this randomized, triple-blinded, placebo-controlled, crossover trial (registered under ClinicalTrials.gov Identifier no. NCT05156697). On the first day, participants underwent a submaximal exercise test on a cycle ergometer to determine their MFO and FATmax intensity during exercise. After 72 hours had elapsed, the participants returned on 2 further days (≥ 72 hours apart) and performed a 60 min steady-state exercise bout (i.e. cycling at their FATmax, constant intensity) after ingesting either 12 mg of DHC or placebo; these conditions were randomized. Respiratory gas exchange was monitored by indirect calorimetry. Serum marker concentrations (i.e. glucose, triglycerides, non-esterified fatty acids (NEFAs), skin temperature, thermal perception, heart rate, and perceived fatigue) were assessed.
Results:
There were no significant differences (P > 0.05) between DHC and placebo conditions in the EE and FATox during exercise. Similarly, no significant changes were observed in glucose, triglycerides, or NEFAs serum levels, neither in the skin temperature nor thermal perception across conditions. Heart rate and perceived fatigue did not differ between conditions.
Conclusions:
DHC supplementation does not affect energy metabolism during exercise in men with overweight/obesity.
... Due to the small diameters of the black globe on the Kestrel heat stress tracker, MRT values were overestimated when wind speed was high, hence additional calibration methods would be beneficial [84]. Moreover, 4-ISO may overestimate T mskin in high T a conditions, while low T a environments may underestimate it [85,86]. Some other environmental parameters, such as daylight, noise and air quality have not been included in this study, as they might confound the subjective thermal perceptions [31,32]. ...
This study set out to understand the dynamics of human thermal sensation and perception associated with outdoor thermal variability in urban contexts. Previous studies found that compact urban forms and green features can contribute to urban climate diversity, and conjectured whether the wax and wane of thermal stress can promote thermal satisfaction in outdoor public spaces. Hence, a stop-and-go method has been developed to accurately capture thermal transitions along urban walks and to provide snapshots of the momentary body thermal sensation and subjective thermal perception. The measurement campaigns carried in late summer involved a total of 40 participants walking for 70 minutes through two waterfront districts in Rome, Italy. Our findings indicate that: (1) the oscillation of air temperature along the dense urban walk is nearly twice as frequent as that along the sparse suburban walk, due to the microclimatic diversity shaped by the compact urban fabrics, pocket parks and tree-lined river banks; (2) the Universal Thermal Climate Index (UTCI) contrast can effectively predict thermal alliesthesia measured by the rate of change of mean skin temperature; (3) subjective perception shows a significant trend but a poorer model fit predicted by UTCI and Tmskin; (4) two confounders, view and social backgrounds, are proved to affect the regression model between the objective and subjective data. The conclusions emphasise the importance of incorporating spatial and social contexts into the investigation of outdoor thermal comfort via physiological and psychological approaches.
... After anthropometric measurements were performed, wireless iButton temperature loggers (iButton, Maxim Integrated Products, Inc, San Jose, CA, USA) were attached to 17 positions to measure skin temperature (21), and an infrared thermographic image (IRT) of the upper thorax/neck region was made (see below for further details). Next, an intravenous cannula was placed in the antecubital vein to sample blood at 6 time points during the study procedure ( Fig. 1). ...
... Skin temperature of 17 positions of the body was measured using 1-minute intervals with wireless iButton temperature loggers (21). We assessed supraclavicular skin temperature and used previously described equations to estimate the mean (21,24), proximal (21), and distal (21, 25) skin temperatures and to calculate a peripheral temperature gradient (left forearm-left fingertip) as a proxy of peripheral vasoconstriction (26). ...
... Skin temperature of 17 positions of the body was measured using 1-minute intervals with wireless iButton temperature loggers (21). We assessed supraclavicular skin temperature and used previously described equations to estimate the mean (21,24), proximal (21), and distal (21, 25) skin temperatures and to calculate a peripheral temperature gradient (left forearm-left fingertip) as a proxy of peripheral vasoconstriction (26). All data were analyzed using Temperatus software (http://profith.ugr.es/temperatus) ...
Context
Cold exposure mobilizes lipids to feed thermogenic processes in organs, including brown adipose tissue (BAT). In rodents, BAT metabolic activity exhibits a diurnal rhythm, which is highest at the start of the wakeful period.
Objective
To investigate whether cold-induced thermogenesis displays diurnal variation in humans, and differs between males and females.
Design
Randomized crossover study.
Participants
Twenty-four young and lean males (n=12) and females (n=12).
Intervention
2.5-hour personalized cooling using water-perfused mattresses in the morning (7:45 AM) and evening (7:45 PM), with one day in between.
Main outcome measures
Energy expenditure (EE) and supraclavicular skin temperature in response to cold exposure.
Results
In males, cold-induced EE was higher in the morning than in the evening (+54±10% vs. +30±7%, P=0.05). By contrast, cold-induced EE did not differ between the morning and the evening in females (+37±9% vs. +30±10%, P=0.42). Additionally, only in males, supraclavicular skin temperature upon cold increased more in the morning than in the evening (+0.2±0.1°C vs. -0.2±0.2°C, P=0.05). In males, circulating free fatty acid (FFA) levels were increased after cold in the morning, but not in the evening (+90±18% vs. +9±8%, P<0.001). In females, circulating FFA (+94±21% vs. +20±5%, P=0.006), but also triglycerides (+42±5% vs. +29±4%, P=0.01) and cholesterol levels (+17±2% vs. 11±2%, P=0.05) were more increased after cold exposure in the morning, than in the evening.
Conclusions
Cold-induced thermogenesis is higher in the morning than in the evening in males, however, lipid metabolism is more modulated in the morning than in the evening in females.
... For the analyses of this study, we only used the skin temperature measures recorded by the iButtons of the left hand and right supraclavicular area, as well as the skin temperature recorded by other iButtons which were then used to calculate the overall mean [41] and proximal [42] skin temperatures [see references [5,43] for further information]. These calculations were done based on the following equations: ...
Background
Harnessing cold-induced thermogenesis (CIT) and brown adipose tissue (BAT) activity has been proposed as a means of counteracting a positive energy balance, and thus of combating obesity and its related comorbidities. However, it has remained unclear whether CIT and BAT activity show diurnal variation in humans - knowledge that might allow treatments based on these factors to be time-optimized.
Methods
A randomized crossover experiment was designed to examine whether CIT shows morning/evening variation in young, healthy adults (n=14, 5 women). On the first experimental day, subjects' shivering thresholds were determined following a cooling protocol. After ≈96 h had elapsed, the subjects then returned on two further days (approx. 48 h apart) at 08:00 h or 18:00 in random order. On both the latter days, the resting energy expenditure (REE) was measured before the subjects underwent personalized cold exposure (i.e., according to their shivering threshold). CIT was then assessed for 60 min by indirect calorimetry. In an independent cross-sectional study (n=133, 88 women), subjects came to the laboratory between 8:00 and 18:00 h and their BAT ¹⁸F-fluordeoxyglucose (¹⁸F-FDG) uptake was assessed after personalized cold stimulation.
Results
Both the REE and CIT were similar in the morning and evening (all P>0.05). Indeed, 60 min of personalized-mild cold exposure in the morning or evening elicited a similar change in energy expenditure (16.8±12.8 vs. 15.7±15.1 % increase above REE, P=0.72). BAT ¹⁸F-FDG uptake was also similar in the morning, evening and afternoon (all P>0.05).
Conclusion
CIT does not appear to show morning/evening variation in young health adults, with the current study design and methodology. BAT ¹⁸F-FDG uptake appears not to change across the day either, although experiments with a within-subject study design are needed to confirm these findings.
Registered under ClinicalTrials.gov Identifier no. NCT02365129.
... The body temperature was estimated as average of the values measured at the medial metatarsal area (aka, distal temperature) and at the infraclavicular areas (aka, proximal temperature) each 10 min. The Thermochron iButton® (DS1921 H) has been used extensively with human to measure temperature data and also used as a circadian marker [24,55,56]. It can measure temperatures from +15 to +46 • C with an accuracy of ±1 • C at a 0.125 • C resolution [24,55]. ...
Circadian rhythms modulate physiological and behavioral processes of approximately 24-h periodicity. Alterations in the circadian timing system may lead to cardiovascular, metabolic or neurological diseases, cancers and sleep disorders, as well as to disruption of quality of life. Circadian rhythms can be tracked via laboratory tests measuring hormones in salivary, urinary or blood samples, which are collected in controlled environments. These tests are unsuitable for continuous monitoring in real-life, being expensive and time consuming, producing discrete information (i.e., few values per day) and requiring controlled environmental conditions (e.g., exposure to light can alter the samples). Thus, there is a need to develop non-invasive methods and tools to track circadian rhythms in real-life conditions.
In this study, 10 healthy participants wore commercial medical-rated (i.e., CE-marked) wearable sensors, which continuously measured ECG, skin body temperature and physical activity for two consecutive days. Up to 10 salivary samples per day were taken and sent to a laboratory for measuring melatonin, which was used as proxy for circadian rhythm tracking.
The results presented in this paper demonstrated that Heart Rate Variability (HRV) measures, physical activity and skin temperature changed significantly after the onset of melatonin. The deep-learning model presented in this study detected the onset of melatonin with 71 % accuracy, 67 % sensitivity, 75 % specificity and 77 % area under the curve (AUC).
The current study concluded that deep learning could be used to track melatonin-onset in real-life, using physiological and behavioral measures monitored via wearable and easy-to-use sensors.
... The shivering threshold assessment methodology has been extensively described elsewhere (23,28). In brief, after voiding, the participants dressed with standardized clothes (clothing insulation value: 0.20). ...
Objective:
This study aimed to describe the energy expenditure (EE) and macronutrient oxidation response to an individualized nonshivering cold exposure in young healthy adults.
Methods:
Two different groups of 44 (study 1: 22.1 [SD 2.1] years old, 25.6 [SD 5.2] kg/m2 , 34% men) and 13 young healthy adults (study 2: 25.6 [SD 3.0] years old, 23.6 [SD 2.4] kg/m2 , 54% men) participated in this study. Resting metabolic rate (RMR) and macronutrient oxidation rates were measured by indirect calorimetry under fasting conditions in a warm environment (for 30 minutes) and in mild cold conditions (for 65 minutes, with the individual wearing a water-perfused cooling vest set at an individualized temperature adjusted to the individual's shivering threshold).
Results:
In study 1, EE increased in the initial stage of cold exposure and remained stable for the whole cold exposure (P < 0.001). Mean cold-induced thermogenesis (9.56 ± 7.9 kcal/h) was 13.9% ± 11.6% of the RMR (range: -14.8% to 39.9% of the RMR). Carbohydrate oxidation decreased during the first 30 minutes of the cold exposure and later recovered up to the baseline values (P < 0.01) in parallel to opposite changes in fat oxidation (P < 0.01). Results were replicated in study 2.
Conclusions:
A 1-hour mild cold exposure individually adjusted to elicit maximum nonshivering thermogenesis induces a very modest increase in EE and a shift of macronutrient oxidation that may underlie a shift in thermogenic tissue activity.
... Eighteen wireless iButton temperature sensors were placed as adapted from 14 prescribed ISO-defined positions 32 33 Data were analysed using Temperatus software. 34 Armpit temperature was estimated and used as a proxy of core body temperature. ...
Aims:
To compare the effects of cold exposure and the β3-adrenergic receptor agonist mirabegron on plasma lipids, energy expenditure and brown adipose tissue (BAT) activity in South Asians versus Europids.
Material and methods:
Ten lean Dutch South Asian (age 18-30 years; BMI 18-25 kg/m2 ) and ten age- and BMI-matched Europid men participated in a randomized, double-blinded, cross-over study consisting of three interventions; short-term (approx. 2 hours) cold exposure, mirabegron (200 mg one dose p.o.) and placebo. Before and after each intervention, we performed lipidomic analysis in serum, assessed resting energy expenditure (REE) and skin temperature, and measured BAT fat fraction by MRI.
Results:
In both ethnicities, cold exposure increased levels of many serum lipid species, whereas mirabegron only increased free fatty acids. Cold exposure increased lipid oxidation in both ethnicities, while mirabegron increased lipid oxidation in Europids only. Cold exposure and mirabegron enhanced supraclavicular skin temperature in both ethnicities. Cold exposure decreased BAT fat fraction in both ethnicities. After combination of data from both ethnicities, mirabegron decreased BAT fat fraction compared to placebo.
Conclusions:
In South Asians and Europids, cold exposure and mirabegron induced beneficial metabolic effects. When combining both ethnicities, cold exposure and mirabegron increased REE and lipid oxidation, coinciding with a higher supraclavicular skin temperature and lower BAT fat fraction. This article is protected by copyright. All rights reserved.
