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Histogramm zur Alters- und Geschlechtsverteilung der Referenzpopulation aus der LIFE Child Kohorte zum Erstbesuch (Gesamt: n=1779, Jungen: n=903, Mädchen: n=876).
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Zusammenfassung
Einleitung: Es werden pädiatrische Referenzintervalle zu eisenabhängigen Parametern kontinuierlich über das Alter unter Anwendung des, in der Laboratoriumsmedizin noch wenig bekannten, R-Pakets GAMLSS aus einer hoch standardisierten Probenpopulation ermittelt.
Methoden: 2778 Blutproben von LIFE Child-Probanden im Alter von 2,5 bis 1...
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Objectives
The ‘Thomas plot’ is a very helpful diagnostic tool for evaluation, monitoring and therapy of the iron status and on the hemoglobinization of the reticulocytes of patients. In 2021 Roche Diagnostics launched a second generation assay for determination of the soluble transferrin receptor (sTfR). Here we compare the old and the new assay f...
Citations
... Additionally, two findings of our study stand out: First, age groups can only roughly approximate the dynamics in children's laboratory test results, and second, the dynamics in the first months of life require particular attention. The arguments for (and against) continuous representations of pediatric reference intervals have been discussed extensively by the former International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)'s Task Force on Pediatric Laboratory Medicine's chair Michael Metz [3,4,18], CALIPER [6,19], HAPPI Kids [7,20], the German LIFE study [21,22], and us [10][11][12][13]. There is general agreement that continuous approaches enable a more accurate representation of pediatric dynamics, although challenges to their integration into laboratory information systems remain, and no consensus exists whether continuous reference intervals are warranted for all analytes and age groups or only for those analytes that exhibit the most complex dynamics. ...
Objectives:
Assessment of children's laboratory test results requires consideration of the extensive changes that occur during physiological development and result in pronounced sex- and age-specific dynamics in many biochemical analytes. Pediatric reference intervals have to account for these dynamics, but ethical and practical challenges limit the availability of appropriate pediatric reference intervals that cover children from birth to adulthood. We have therefore initiated the multi-center data-driven PEDREF project (Next-Generation Pediatric Reference Intervals) to create pediatric reference intervals using data from laboratory information systems.
Methods:
We analyzed laboratory test results from 638,683 patients (217,883-982,548 samples per analyte, a median of 603,745 test results per analyte, and 10,298,067 test results in total) performed during patient care in 13 German centers. Test results from children with repeat measurements were discarded, and we estimated the distribution of physiological test results using a validated statistical approach (kosmic).
Results:
We report continuous pediatric reference intervals and percentile charts for alanine transaminase, aspartate transaminase, lactate dehydrogenase, alkaline phosphatase, γ-glutamyl-transferase, total protein, albumin, creatinine, urea, sodium, potassium, calcium, chloride, anorganic phosphate, and magnesium. Reference intervals are provided as tables and fractional polynomial functions (i.e., mathematical equations) that can be integrated into laboratory information systems. Additionally, Z-scores and percentiles enable the normalization of test results by age and sex to facilitate their interpretation across age groups.
Conclusions:
The provided reference intervals and percentile charts enable precise assessment of laboratory test results in children from birth to adulthood. Our findings highlight the pronounced dynamics in many biochemical analytes in neonates, which require particular consideration in reference intervals to support clinical decision making most effectively.
... As part of the Leipzig Research Centre for Civilization Diseases (LIFE), the population-based cohort study LIFE Child has started recruiting urban, primarily healthy infants, children, and adolescents in Leipzig (Germany) in 2011. This large population-based cohort has already been used to establish reference intervals for serum lipids [26], liver enzymes [27], and iron-related blood parameters [28] in children. The examinations take place in the LIFE Child study center and are carried out by trained medical staff using highly standardized procedures [29,30]. ...
Background
This study aims to establish age- and gender-specific cystatin C (CysC) reference values for healthy infants, children, and adolescents and to relate them to pubertal stage, height, weight, and body mass index (BMI).
Methods
Serum CysC and creatinine levels of 6217 fasting, morning venous blood samples from 2803 healthy participants of the LIFE Child study (age 3 months to 18 years) were analyzed by an immunoassay. Recruitment started in 2011; 1636 participants provided at least one follow-up measurement. Percentiles for CysC were calculated. Age- and gender-related effects of height, weight, BMI, and puberty status were assessed through linear regression models.
Results
Over the first 2 years of life, median CysC levels decrease depending on height (ß = − 0.010 mg/l/cm, p < 0.001) and weight (ß = − 0.033 mg/l/kg, p < 0.001) from 1.06 to 0.88 mg/l for males and from 1.04 to 0.87 mg/l for females. Following the second year of age, the levels remain stable for eight years. From 11 to 14 years of age, there is an increase of median CysC levels in males to 0.98 mg/l and a decrease in females to 0.86 mg/l. The change is associated with puberty (ß = 0.105 mg/l/Tanner stage, p < 0.001 in males and ß = − 0.093 mg/l/Tanner stage, p < 0.01 in females) and in males with height (ß = 0.003 mg/l/cm, p < 0.001).
Conclusions
CysC levels depend on age, gender, and height, especially during infancy and puberty. We recommend the use of age- and gender-specific reference values for CysC serum levels for estimating kidney function in clinical practice.
... (20) Estimation of parameters as continuous functions of age seems to be a more appropriate approach to reflect the physiological development of laboratory analytes. (9,21) Because LIFE Child has a longitudinal study design and recruits families participated with more than one child, our sampled data contain multiple measurements per child as well as measurements of siblings. Therefore, percentile calculations had to follow an adapted approach. ...
The present study aims to clarify the effects of sex, age, body mass index (BMI), and puberty on transaminase serum levels in children and adolescents and to provide new age- and sex-related percentiles for alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyltransferase (GGT). Venous blood and anthropometric data were collected from 4,126 cases. Excluded were cases of participants with potential hepatotoxic medication, with evidence of potential illness at the time of blood sampling and non-normal BMI (BMI <10th or >90th). The resulting data (N = 3,131 cases) were used for the calculations of ALT, AST, and GGT percentiles. Age- and sex-related reference intervals were established by using an LMS method of Cole-type method. Serum levels of transaminases follow age-specific patterns and relate to the onset of puberty. This observation is more pronounced in girls than in boys. ALT percentiles showed similar-shaped patterns in both sexes. Multivariate regression confirmed significant effects of puberty and BMI-SDS (β = 2.21) on ALT. Surprisingly, AST serum levels were negatively influenced by age (β = -1.42) and BMI-SDS (β = -0.15). GGT percentiles revealed significant sex-specific differences, correlated positively with age (β = 0.37) and showed significant association with BMI-SDS (β = 1.16).
Conclusion:
Current reference values of ALT, AST, and GGT serum levels were calculated for children between 11 months and 16.0 years, using modern analytical and statistical methods. This study extends the current knowledge about transaminases by revealing influences of age, sex, BMI, and puberty on serum concentrations of all three parameters and has for these parameters one of the largest sample sizes published so far. (Hepatology 2017).
Purpose
Percentile curves of refractive development for German children were generated. We hypothesize that refraction in children in central Europe might differ from data in central Asia.
Methods
Non-cycloplegic refraction was measured using the ZEISS i.Profiler plus (Carl Zeiss Vision GmbH, Germany) in 1999 children, of which were 1046 male and 953 female, aged 3 to 18 years. Reference curves were calculated with the R-package GAMLSS as continuous function of age.
Results
There were only little differences for all centiles between the genders at 3 years and a general trend towards more myopia with increasing age. For the 97th centile and the 3rd centile, girls showed higher myopia/ less hyperopia than boys. Between the age of 3 and 18, the median refraction became -0.68 D and -0.74 D more myopic for boys and girls, respectively. At the same time, the 97th centile for boys changed +0.29 D towards hyperopia and in girls -0.52 D towards myopia. A general myopic trend was seen in the 3rd centile, which was -2.46 D for boys and -2.98 D for girls. For both genders, the median became less than zero at the age of 10 years but did not become myopic (less than -0.5 D) up to the age of 18.
Conclusion
Our analysis presents the first reference curve for refraction in central Europe. In comparison to data from China and Korea, there is only little difference at the age of 5 years in all centiles which then increases continuously. For all ethnicities, a trend towards myopia with increasing age could be observed, but myopia progression is much higher in China and Korea than in Germany. The most marked differences can be seen in the lower centiles. Further investigations should clarify whether commencement of preschool activities with prolonged near-work initiates the divergence in refractive development.
Objectives
In the present study, we examined the relation between socioeconomic status (SES) and the physiological distribution of iron-related blood parameters.
Design
This is a cross-sectional analysis of longitudinal population-based cohort study.
Setting
Based on a sample of healthy participants from a German research centre, various blood parameters and values of clinical examinations and questionnaires were collected.
Participants
A total of 1206 healthy volunteers aged 2.5 to 19 years, one child per family randomly selected, were included.
Primary and secondary outcome measures
Associations between the SES of children by Winkler-Stolzenberg Index (WSI) and its dimensions (income, education, occupation) and iron-related blood parameters (haemoglobin, ferritin and transferrin) were analysed by linear regression analyses. Gender and pubertal stage were included as covariables. Additionally, associations between SES of children by WSI and physical activity (side-to-side jumps, push-ups) as well as body mass index (BMI) were analysed by linear regression analyses.
Results
Children with high WSI or family income showed significantly increased z-scores for haemoglobin (P=0.046; P<0.001). Children with increased WSI or family income showed significantly lower z-scores for transferrin (P<0.001). There was a significant correlation between haemoglobin and gender (P<0.001) and between transferrin and pubertal stage (P=0.024). Furthermore, physical activity was positively correlated and BMI was negatively correlated with WSI (P<0.001).
Discussion
Our data show an association between SES and the distribution of iron-dependent parameters. Lower SES is correlated with lower values for haemoglobin and higher values for transferrin. Furthermore, we demonstrate that physical activity and BMI are associated with SES. Whereas higher SES is correlated with higher values for physical activity and lower BMI. Our parameters are standardised as z-scores with the advantages that the results are comparable across different age groups and present physiological courses.
Trial registration number
NCT02550236; Results.
