Fat and lean BMI reference curves in children and adolescents and their utility in identifying excess adiposity compared with BMI and percentage body fat

Screening Accuracy of BMI for Adiposity Among 8- to 19-Year-Olds

BACKGROUND AND OBJECTIVES

Although the limitations of BMI have long been recognized, there are recent concerns that it is not a good screening tool for adiposity. We therefore examined the cross-sectional relation of BMI to adiposity among 6923 8- to 19-year-olds in the National Health and Nutrition Survey from 2011 through 2018.

METHODS

Participants were scanned with dual-energy x-ray absorptiometry. Adiposity was expressed as fat mass index (FMI, fat mass kg ÷ m2) and percentage of body fat (%fat). Lean mass was expressed as lean mass index (LMI, lean mass ÷ m2). Regression models and 2 × 2 tables were used to assess the relation of BMI to FMI, %fat, and LMI.

RESULTS

Age and BMI accounted (R2) for 90% to 94% of the variability of FMI and LMI in each sex. Associations with %fat were weaker (R2s ∼0.70). We also examined the screening abilities of a BMI ≥ Centers for Disease Control and Prevention 95th percentile for high levels of adiposity and LMI. Cut points were chosen so that prevalences of high values of these variables would be similar to that for high BMI. Of participants with a high BMI, 88% had a high FMI, and 76% had a high %fat. Participants with a high BMI were 29 times more likely to have a high FMI than those with lower BMIs; comparable relative risks were 12 for high %fat and 14 for high LMI.

CONCLUSIONS

Despite its limitations, a high BMI is a very good screening tool for identifying children and adolescents with elevated adiposity.

Lower subjective social status is associated with increased adiposity and self-reported eating in the absence of hunger due to negative affect among children reporting teasing distress

OBJECTIVES

Low social standing and teasing are independently associated with increased body mass index (BMI) and overeating in children. However, children with low social status may be vulnerable to teasing.

METHODS

We tested the statistical interaction of subjective social status (SSS) and subjective socioeconomic status (SSES) and teasing distress on BMI, fat mass index (FMI), and eating in the absence of hunger (EAH) in children (Mage = 13.09 years, SD = 2.50 years; 27.8% overweight/obese). Multiple linear regressions identified the main effects of self-reported SSS (compared to peers in school), distress due to teasing, and their interaction on BMI (n = 115), FMI (n = 114), and child- (n = 100) and parent-reported (n = 97) EAH.

RESULTS

Teasing distress was associated with greater BMI, FMI, and child-reported EAH due to negative affect (a subscale of EAH) and total EAH scores. There were no associations of SSS with these outcomes. However, there was an interaction between SSS and teasing distress for BMI, FMI, and EAH from negative affect such that lower SSS was associated with higher BMI, FMI, and EAH from negative affect in the presence of teasing distress. However, there were no main effects or interactions (with teasing distress) of SSES on the outcomes.

CONCLUSIONS

These findings suggest that the relationship between lower SSS and increased adiposity and overeating behaviors may be exacerbated by other threats to social standing, such as teasing. Children exposed to multiple social threats may be more susceptible to eating beyond physiological need and obesity than those who experience a single form of perceived social disadvantage.

Per- and polyfluoroalkyl substances and bone mineral content in early adolescence: Modification by diet and physical activity

BACKGROUND

Per- and polyfluoroalkyl substance (PFAS) exposures may negatively impact bone mineral accrual, but little is known about potential mitigators of this relation. We assessed whether associations of PFAS and their mixture with bone mineral content (BMC) in adolescence were modified by diet and physical activity.

METHODS

We included 197 adolescents enrolled in a prospective pregnancy and birth cohort in Cincinnati, Ohio (2003-2006). At age 12 years, we collected serum for PFAS measurements and used dual-energy x-ray absorptiometry to measure BMC. We calculated dietary calcium intake and Health Eating Index (HEI) scores from repeated 24-h dietary recalls, physical activity scores using the Physical Activity Questionnaire for Older Children (PAQ-C), and average moderate to vigorous physical activity (MVPA) based on accelerometry. We estimated covariate-adjusted differences in BMC z-scores per interquartile range (IQR) increase of individual PFAS concentrations using linear regression and per simultaneous IQR increase in all four PFAS using g-computation. We evaluated effect measure modification (EMM) using interaction terms between each modifier and PFAS.

RESULTS

Higher serum perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorononanoic acid concentrations and the PFAS mixture were associated with lower BMC z-scores. An IQR increase in all PFAS was associated with a 0.27 (-0.54, 0.01) lower distal radius BMC z-score. Associations with lower BMC were generally stronger among adolescents classified as < median for calcium intake, HEI scores, or MVPA compared to those ≥ median. The difference in distal radius BMC z-score per IQR increase in all PFAS was -0.38 (-0.72, -0.04) for those with

CONCLUSION

Healthy, calcium-rich diets and higher intensity physical activity may mitigate the adverse impact of PFAS on adolescent bone health.

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Key Words

• Adolescent health
• Bone mineral content
• Calcium
• Diet
• Perfluoroalkyl substances
• Physical activity

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MESH Headings

• Humans
• Female
• Fluorocarbons/blood
• Male
• Bone Density/drug effects
• Child
• Adolescent
• Diet
• Environmental Pollutants/blood
• Prospective Studies
• Ohio
• Alkanesulfonic Acids/blood
• Exercise
• Motor Activity/drug effects

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Grants

• R01 ES030078 NIEHS NIH HHS
• R01 ES033252 NIEHS NIH HHS
• R01 ES027224 NIEHS NIH HHS
• L40 ES032257 NIEHS NIH HHS
• P01 ES011261 NIEHS NIH HHS
• R01 ES032836 NIEHS NIH HHS
• R01 ES028277 NIEHS NIH HHS
• T32 ES007141 NIEHS NIH HHS
• R01 ES025214 NIEHS NIH HHS
• R01 ES020349 NIEHS NIH HHS

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Affiliation(s)

Jessie P Buckley Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Junyi Zhou Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
Katherine M Marquess Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
Bruce P Lanphear Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
Kim M Cecil Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Aimin Chen Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA
Clara G Sears Christina Lee Brown Envirome Institute, Department of Medicine, Division of Environmental Medicine, University of Louisville, KY, USA
Yingying Xu Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Kimberly Yolton Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Heidi J Kalkwarf Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Joseph M Braun Department of Epidemiology, Brown University, Providence, USA
Jordan R Kuiper Department of Environmental and Occupational Health, The George Washington University Milken Institute School of Public Health, Washington, D.C., USA

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Cardiotoxicity of CPX-351 in children and adolescents with relapsed AML: a Children's Oncology Group report

Introduction

Anthracyclines are effective in treating acute myeloid leukemia (AML) but limited by cardiotoxicity. CPX-351, a liposomal daunorubicin and cytarabine, may provide therapeutic benefit with less cardiotoxicity. Acute changes in left ventricular systolic function and cardiac biomarkers were evaluated after a cycle of CPX-351 in children with relapsed AML treated on the phase 1/2 Children's Oncology Group study, AAML1421.

Methods

Subjects received 135 units/m2/dose of CPX-351 on days 1, 3, and 5 as cycle 1. Echocardiograms were performed and centrally quantitated at baseline and at the end of cycle 1 (day 29 +/- 1 week). High sensitivity troponin (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at baseline and serially through the end of cycle 1 (days 5, 8, 15, 22 and 29). Differences between baseline and post-CPX-351 echo/biomarker measures were analyzed using Wilcoxon signed rank tests. Linear regression was used to model post-CPX-351 left ventricular ejection fraction (LVEF) with cTnT/NT-proBNP at each time point, controlling for baseline LVEF. Cancer therapy related cardiac dysfunction (CTRCD) was defined as a decline in LVEF of ≥10%-<50%.

Results

Twenty-five of 38 heavily anthracycline pre-treated (median 348 mg/m2 daunorubicin equivalents) subjects enrolled on AAML1421 were included in the cardiac analyses. At baseline, centrally quantitated LVEF was <50% in 8 of 25 subjects (32%) with a median LVEF of 53.8% [48.0, 56.9]. Following CPX-351, LVEF declined significantly (ΔLVEF -3.3% [-7.8, 0]) and 6 of 25 subjects (24%) experienced CTRCD. Amongst all subjects, hs-cTnT was modestly increased at end of cycle 1 compared to baseline [baseline hs-cTnT 7.2 (3, 10.6); ΔcTnT 1.80 (0, 6.1), p = 0.03]. NT-proBNP remained stably elevated without significant change. No significant associations were seen between NT-proBNP or cTnT levels and post-CPX-351 LVEF.

Discussion

In this single arm study of anthracycline pre-treated children exposed to CPX-351, baseline abnormalities in cardiovascular function were prevalent. Following CPX-351, LVEF decreased, cTnT increased, and NT-proBNP did not change. Longer follow-up is needed to determine whether these changes result in clinically meaningful long-term decrements in cardiac function. An ongoing randomized trial of CPX-351 compared to standard anthracyclines in anthracycline naïve patients will provide further insight into the cardiac effects of CPX-351 (ClinicalTrials.gov; NCT04293562).

High muscular fitness level may positively affect bone strength and body composition in children with overweight and obesity

Muscular fitness plays a major role in bone health and body composition in overweight and obese children. It is key that the development of this muscle fitness is affected by absolute isometric strength and dynamic strength.

PURPOSE

To compare bone health and body composition between overweight/obese children considering muscular fitness (MF) levels, and to investigate whether weight-bearing dynamic or absolute isometric strength, both involved in the development of this muscular fitness, are more related with bone health.

METHODS

MF of 59 overweight or obese children (10.1 ± 0.9 years, 27 females) was measured by a countermovement jump (CMJ), handgrip, and maximal isometric strength of knee extension. Participants were divided into four groups depending on their MF level performing a cluster analysis: 16 children with high MF (HMF) in all tests, 18 with high performance in isometric strength (HIS), 15 with high performance in CMJ (HCMJ) and 10 low isometric and low dynamic force values (LMF). Body composition values were measured by dual energy X-ray absorptiometry, and bone strength values were assessed by peripheral quantitative computed tomography. Motor skills were evaluated using TGMD-3. Multivariate analysis of covariance test was applied to analyse bone strength differences between children in the different MF groups, using maturity offset, height and weight as covariates, and correlations were investigated.

RESULTS

HMF excelled in bone health. HIS had higher cortical bone area, periosteal circumference, bone mass, polar strength strain index and fracture load than LMF, while HCMJ only showed better results in trabecular bone area than LMF. HMF had significantly better values of fracture load and periosteal and endosteal circumferences than HCMJ, but not than HIS.

CONCLUSIONS

High MF level shows positive effects on bone health in overweight/obese children. Those with highest isometric strength had better bone health compared to those with higher dynamic strength.

TRIAL REGISTRATION

The research project was registered in a public database Clinicaltrials.gov in June 2020 with the identification number NCT04418713.

Estimating effects of longitudinal and cumulative exposure to PFAS mixtures on early adolescent body composition

Few methods have been used to characterize repeatedly measured biomarkers of chemical mixtures. We applied latent profile analysis (LPA) to serum concentrations of 4 perfluoroalkyl and polyfluoroalkyl substances (PFAS) measured at 4 time points from gestation to age 12 years. We evaluated the relationships between profiles and z scores of height, body mass index, fat mass index, and lean body mass index at age 12 years (n = 218). We compared LPA findings with an alternative approach for cumulative PFAS mixtures using g-computation to estimate the effect of simultaneously increasing the area under the receiver operating characteristic curve (AUC) for all PFAS. We identified 2 profiles: a higher PFAS profile (35% of sample) and a lower PFAS profile (relative to each other), based on their average PFAS concentrations at all time points. The higher PFAS profile had generally lower z scores for all outcomes, with somewhat larger effects for males, though all 95% CIs crossed the null. For example, the higher PFAS profile was associated with a 0.50-unit lower (β = -0.50; 95% CI, -1.07 to 0.08) BMI z score among males but not among females (β = 0.04; 95% CI, -0.45 to 0.54). We observed similar patterns with AUCs. We found that a higher childhood PFAS profile and higher cumulative PFAS mixtures may be associated with altered growth in early adolescence. This article is part of a Special Collection on Environmental Epidemiology.

The Accumulative Effect of Multiple Postnatal Risk Factors with the Risk of Being Overweight/Obese in Late Childhood

Most past studies focused on the associations of prenatal risk factors with the risks of childhood overweight/obesity. Instead, more postnatal risk factors are modifiable, with less knowledge of their cumulative effects on childhood obesity. We analyzed data of 1869 children in an Australian birth cohort. Key postnatal risk factors included: maternal and paternal overweight/obesity during the child's infancy, tobacco exposure, low family socioeconomic score, breastfeeding duration < 6 months, early introduction of solid foods, and rapid weight gain during infancy. The risk score was the sum of the number of risk factors. The primary outcome is overweight/obesity in late childhood (11-12 years); secondary outcomes are high-fat mass index (FMI), body fat percentage (BF%), and waist-to-height ratio (WHtR). Poisson regression models were used in the analyses. Children with higher risk scores had higher risks of overweight/obesity (p-for-trends < 0.001). After adjusting covariates, compared with those with 0-1 risk factors, children with 4-6 risk factors had 4.30 (95% confidence interval: 2.98, 6.21) times higher risk of being overweight/obesity; the relative risks for high FMI, BF%, and WHtR were 7.31 (3.97, 13.45), 4.41 (3.00, 6.50), and 6.52 (3.33, 12.74), respectively. Our findings highlighted that multiple postnatal risk factors were associated with increased risks of being overweight/obesity in late childhood.

Insufficient Bone Mineralization to Sustain Mechanical Load of Weight in Obese Boys: A Cross-Sectional Study

CONTEXT

The increase in bone mineral content (BMC) and density (BMD) measured by dual-energy x-ray absorptiometry (DXA) in obese children may not sustain the mechanical load associated with weight, and the factors influencing bone mineralization are not well known.

OBJECTIVE

We described bone mineralization in boys with overweight/obesity and leanness in relation to body composition.

METHODS

Cross-sectional study in the Pediatric Endocrinology Unit of Angers University Hospital with 249 overweight/obese boys aged 8-18 who underwent DXA and insulin, testosterone, and IGF-1 measurements. Bone mineralization was compared with data from 301 lean boys of similar age and height from NHANES 2011-2015, using the same DXA model. Path analyses were performed to evaluate factors associated with total body less head (TBLH) BMC.

RESULTS

The mean age- and height-adjusted difference in TBLH BMC between obese and lean boys was 241 ± 20 g/cm2. Each 1 kg/m2 increase in BMI was associated with +39 ± 6 g of TBLH BMC in lean subjects vs + 25 ± 3 g in obese subjects (P < .05). Each 1 kg/m2 increase in lean BMI (LBMI) was associated with +78 ± 5 g of TBLH BMC in lean and obese boys, and each 1 kg/m2 increase in fat mass index (FMI) was associated with a decrease of 9 ± 3 g of TBLH BMC. The TBLH BMC was directly positively influenced by LBMI and indirectly and positively influenced by IGF-1, testosterone, and insulin (mediated through height and LBMI). FMI indirectly influenced TBLH BMC, both positively through LBMI and negatively through its negative impact on IGF-1 and testosterone.

CONCLUSION

The increase in bone mineralization in obese children does not adapt to the increase in body mass.

Comparison of body mass index and fat mass index to classify body composition in adolescents-The EVA4YOU study

The objectives of this study were to develop age- and sex-specific reference percentiles for fat mass index (FMI) and fat-free mass index (FFMI) in adolescents aged 14 to 19 years and to determine differences in overweight/obesity classification by FMI and body mass index (BMI). The EVA4YOU study is a single-center cross-sectional study conducted in western Austria. Cardiovascular risks including anthropometric measurements and bioelectrical impedance analysis were assessed in adolescents (mean age 17 years). FMI and FFMI were calculated as the ratio of fat mass (FM) and fat-free mass (FFM) to the square of height and compared to study population-specific BMI percentiles. One thousand four hundred twenty-two adolescents were included in the analysis. Girls had a significantly higher mean FM and FMI and a significantly lower mean FFM, FFMI (p < 0.001, each), and mean BMI (p = 0.020) than boys. Body composition classification by FMI and BMI percentiles shows a concordance for the < 75th and > 97th percentile, but a significant difference in percentile rank classifications between these two cut-off values (all p < 0.05). Based on FMI, 15.5% (221/1422) of the whole population and 29.4% (92/313) of those between the 75th and 97th percentiles are classified one category higher or lower than those assigned by BMI.

CONCLUSION

 Classification of normal or pathologic body composition based on BMI and FMI shows good accordance in the clearly normal or pathologic range. In an intermediate range, FMI reclassifies categories based on BMI in more than a quarter of adolescents. Cut-off values to differentiate normal from pathologic FMI values on a biological basis are needed.

TRIAL REGISTRATION

The study is registered at www.

CLINICALTRIALS

gov  (Identifier: NCT04598685; Date of registration: October 22, 2020).

WHAT IS KNOWN

• Chronic non-communicable diseases (NCDs) are the leading cause of morbidity and mortality globally, with major risk factors including unhealthy diets, harmful behaviors, and obesity. Obesity in children and adolescents is a key risk factor for later NCDs, which is commonly measured by Body Mass Index (BMI). • BMI can be misleading as it doesn't distinguish between fat mass (FM) and fat-free mass (FFM), leading to potential misclassification of obesity in children. Previous studies have already suggested the use of the Fat Mass Index (FMI) and Fat-Free Mass Index (FFMI) as a more accurate measures of body composition.

WHAT IS NEW

• This study adds the first age- and sex-specific reference values for FMI and FFMI in Austrian adolescents using bioelectrical impedance analysis (BIA) as a safe and secure measurement method of a large representative cohort. • We found percentile misclassification between BMI and FMI when categorizing for obesity, especially in intermediate categories of body composition. Furthermore, when comparing the new reference values for FMI and FFMI to existing ones from the US, UK, and Germany we could show a good alignment within the European cohorts and major differences with American values, indicating and confirming the difference of FMI and FFMI for different populations of different ethnical background, living on different continents.

Body mass composition analysis as a predictor of overweight and obesity in children and adolescents

Introduction

Body mass composition is directly related to health and its disorders are correlated with diseases such as obesity, diabetes, osteoporosis and sarcopenia. The purpose of this study was to analyze body mass composition among traditional elementary school students and ballet school students.

Methods

A total of 340 students participated in the study, 95 of whom attended ballet school and 245 elementary school students. A Tanita BC-418 MA analyzer was used to analyze body mass composition. Such body composition indices as BMI (Body Mass Index), muscle mass, fat mass, lean body mass and water content were evaluated.

Results

The results show statistical significance for BMI between high school ballet students and elementary school ballet students, as well between high school ballet students and elementary school students. Comparisons in relation to gender and schools BMI, statistical significance was obtained for: BHSw (ballet high school women) and EBSw (elementary ballet school women), BHSw and ESw (elementary school women), BHSm (ballet high school men) and EBSm (elementary ballet school men), and between BHSm and ESw. Comparing muscle mass index (kg) between ballet high school and elementary school, between ballet high school and elementary school, and between ballet high school and elementary school - statistical significance was obtained for all comparisons. Analyzing in pairwise comparisons by gender and school achieved a statistically significant difference for: BHSw and EBSw, BHSm and EBSw, EBSw and ESm. Comparing the fat mass index (kg), no significant differences were observed between the analyzed schools and the school and gender of the children studied. The value of the lean body mass index differed significantly between groups by school and gender. Comparing the water content index, statistically significant differences were obtained for school and gender.

Discussion

The body mass composition of ballet school students differs from that of standard school students.

High levels of sleep disturbance across early childhood increases cardiometabolic disease risk index in early adolescence: longitudinal sleep analysis using the Health Outcomes and Measures of the Environment study

STUDY OBJECTIVES

This study examines the impact of sleep duration, bedtime, and sleep disturbance during early childhood on the risk of cardiometabolic disorder (CMD) in early adolescence.

METHODS

Within the Health Outcomes and Measures of Environment Study, we examined sleep patterns of 330 children from ages 2 to 8 years and the relationship of these sleep patterns with cardiometabolic risk measures at age 12 (N = 220). We used a group-based semi-parametric mixture model to identify distinct trajectories in sleep duration, bedtime timing, and sleep disturbance for the entire sample. We then examined the associations between sleep trajectories and CMD risk measures using general linear models using both an unadjusted model (no covariates) and an adjusted model (adjusting for child pubertal stage, child sex, duration of breastfeeding, household income, maternal education, and maternal serum cotinine).

RESULTS

In the unadjusted and adjusted models, we found significant differences in CMD risk scores by trajectories of sleep disturbance. Children in the "high" disturbance trajectory had higher CMD risk scores than those in the 'low' disturbance trajectory (p's = 0.002 and 0.039, respectively). No significant differences in CMD risk were observed for bedtime timing or total sleep time trajectories in the unadjusted or adjusted models.

CONCLUSIONS

In this cohort, caregiver-reported sleep disturbance in early childhood was associated with more adverse cardiometabolic profiles in early adolescence. Our findings suggest that trials to reduce CMD risk via sleep interventions-which have been conducted in adolescents and adults-may be implemented too late.

Association between BMI z-score and body composition indexes with blood pressure and grip strength in school-age children: a cross-sectional study

Childhood obesity is linked to diverse health outcomes, including elevated blood pressure (EBP). Emerging evidence showed that excess fat mass (FM) may have a deleterious impact on blood pressure even in normal-weight children. The primary objective of this study was to assess the association between body weight status by BMI z-score and body composition parameters by conventional bioelectrical impedance analysis (BIA) and bioelectrical impedance vector analysis (BIVA). Also, we aimed to explore the performance of BMI z-score, %FM, and FM index (FMI) in discriminating EBP in a sample of school-age Mexican children. Children were classified as having normal weight, overweight or obesity according to WHO criteria for BMI z-score. FMI was considered high when above 75th percentile, and fat free mass index (FFMI) was considered low when below 25th percentile of the reference population. Body composition was also classified according to the BIVA method and EBP was determined when systolic and/or diastolic blood pressure ≥ 90th percentile. BMI z-score groups were compared by Student´s t-test or the Mann-Whitney U test, or by the chi-square test or Fisher exact test. Receiving operating characteristic (ROC) analysis was performed. 61 children were included (52.5% boys, median age 9.8 (25th, 75th percentiles: 8.5, 11.0)) years. High FMI was observed in 32.3% of children with normal weight. Low FFMI was present in 93.5% of children with normal weight and 53.3% of those with overweight/obesity. According to BIVA, 58.1% and 43.3% of children with normal weight and overweight/obesity were classified as having cachexia. All the three adiposity indicators showed significant areas under the ROC curve (AURC) greater than 0.775 for EBP, with the largest one displayed for FM% (0.794). Hight FMI and low FFMI are common in children with normal weight. Identifying deficiency of FFM might be limited by using solely BMI indicators. Cachexia by BIVA was present in a high proportion of children with either normal weight or overweight/obesity. Both BMI z-score and FM (% and FMI) performed well at discriminating EBP, with a numerically greater AURC observed for FM%. Body composition in pediatric population is relevant for identifying body composition abnormalities at early age.

Dietary Zinc Intakes Are Associated With Skeletal Muscle Mass and Strength in Children and Adolescents: Zinc and Muscle in Children

The purpose of this study was to evaluate the relationship between dietary zinc intakes and skeletal muscle mass and strength in children and adolescents. A retrospective study was conducted using data on United States adolescents aged 8 to 19 years. Data were extracted from the National Health and Nutrition Examination Survey 2011-2014 cycles. Subjects were divided into 3 groups based on the tertiles of dietary zinc intakes. The levels of appendicular skeletal muscle mass divided by weight (ASM/Wt, %) and grip in subjects with the highest tertile were higher than those in subjects with the middle and lowest tertiles (P < .05). Dietary zinc intakes were positively correlated with ASM/Wt (r = .221, P < .001) and grip (r = 0.169, P < .001). After a multivariate analysis, dietary zinc intakes were still significantly associated with ASM/Wt (β = 0.059, P < .001) and grip (β = 0.245, P < .001). The present study demonstrates that dietary zinc intakes were positively associated with skeletal muscle mass and strength in children and adolescents.

Pubertal origin of growth retardation in inborn errors of protein metabolism: A longitudinal cohort study

OBJECTIVES

Inherited amino-acid metabolism disorders (IAAMDs) require lifelong protein-restricted diet. We aimed to investigate: 1/ whether IAAMDs was associated with growth, pubertal, bone mineral apparent density (BMAD) or body composition impairments; 2/ associations linking height, amino-acid mixture (AAM), plasma amino-acids and IGF1 concentrations.

DESIGN

Retrospective longitudinal study of 213 patients with neonatal-onset urea cycle disorders (UCD,n = 77), organic aciduria (OA,n = 89), maple syrup urine disease (MSUD,n = 34), or tyrosinaemia type 1 (n = 13).

METHODS

We collected growth parameters, pubertal status, BMAD, body composition, protein-intake, and IGF1 throughout growth.

RESULTS

Overall final height (n = 69) was below target height (TH): -0.9(1.4) vs. -0.1(0.9) SD, p < 0.001. Final height was ≤ TH-2SD in 12 (21%) patients. Height ≤ - 2SD was more frequent during puberty than during early-infancy and pre-puberty: 23.5% vs. 6.9%, p = 0.002; and vs. 10.7%, p < 0.001. Pubertal delay was frequent (26.7%). Height (SD) was positively associated with isoleucine concentration: β, 0.008; 95%CI, 0.003 to 0.012; p = 0.001. In the pubertal subgroup, height (SD) was lower in patients with vs. without AAM supplementation: -1.22 (1.40) vs. -0.63 (1.46) (p = 0.02). In OA, height and median (IQR) isoleucine and valine concentrations(μmol/L) during puberty were lower in patients with vs. without AAM supplementation: -1.75 (1.30) vs. -0.33 (1.55) SD, p < 0.001; and 40 (23) vs. 60 (25) (p = 0.02) and 138 (92) vs. 191 (63) (p = 0.01), respectively. No correlation was found with IGF1. Lean-mass index was lower than fat-mass index: -2.03 (1.15) vs. -0.44 (0.89), p < 0.001.

CONCLUSIONS

In IAAMDs, growth retardation worsened during puberty which was delayed in all disease subgroups. Height seems linked to the disease, AAM composition and lower isoleucine concentration, independently of the GH-IGF1 pathway. We recommend close monitoring of diet during puberty.

Paediatric dominant and non-dominant handgrip reference curves and the association with body composition

BACKGROUND

Lack of paediatric reference data limits the utility of handgrip strength as a measure of fitness and well-being.

AIM

To develop paediatric handgrip reference curves and evaluate associations with body size and composition and race/ethnicity group.

SUBJECTS AND METHODS

Handgrip, body size and composition data were obtained from National Health and Nutrition Examination Survey 2011-2014 participants aged 6-20 years. Densitometry-derived fat and appendicular lean soft tissue mass index Z-scores (FMIZ, ALSTMIZ) were generated in participants >8 years. Dominant and non-dominant handgrip reference curves were created using the LMS method. Analyses included sample weights to produce nationally representative estimates.

RESULTS

Differences in handgrip strength according to hand dominance increased with age. Handgrip strength was associated with height and arm length Z-scores (R = 0.42 to 0.47) and ALSTMIZ (R = 0.54). Handgrip strength was higher in the non-Hispanic Black group and lower in the Mexican American compared to non-Hispanic White group. Group differences were attenuated when adjusted for height, arm length or ALSTMIZ.

CONCLUSION

Paediatric handgrip reference curves were generated from which individual Z-scores can be calculated separately for dominant versus non-dominant hand and adjusted for body size. Association with ALSTMIZ suggests handgrip Z-score may be used as a measure of functional body composition.

Association of physical activity, sedentary behavior, diet quality with adiposity: a longitudinal analysis in children categorized by baseline weight status

BACKGROUND/OBJECTIVES

Childhood obesity rates have increased in recent years. The effectiveness of future public health interventions to reduce childhood obesity will be enhanced by a better understanding of behavioral factors that influence adiposity in children as they transition from childhood to adolescence. The purpose of this study was to examine whether initial weight status modifies the longitudinal associations of physical activity, sedentary behavior, and diet quality with changes in adiposity over time.

SUBJECTS/METHODS

A total of 658 children (45% boys) were stratified into 3 groups based on 5th grade BMI percentiles ( < 85th, 85-95th, > 95th) and followed from 5th grade to 6th and/or 7th grade. Study variables, including fat-mass-index (FMI), moderate-to-vigorous physical activity (MVPA), diet quality, and sedentary behavior, were measured at 5th, 6th, and/or 7th grades. Separate growth curve models were conducted within each weight status group to examine the associations between MVPA, sedentary behavior, diet quality and adiposity, operationalized as FMI. All models controlled for sex, maturity offset, race, and parent education.

RESULTS

Of the 658 children, 53% were classified with normal weight at baseline, 18% with overweight, and 29% with obesity. Associations between MVPA, sedentary behavior, diet quality and FMI varied within each weight status group. MVPA was negatively associated with adiposity (FMI) for all weight status groups. Diet quality and sedentary behavior were associated with adiposity only in children with obesity at baseline; neither diet quality nor sedentary behavior was associated with FMI for those with overweight.

CONCLUSIONS

MVPA was negatively associated with adiposity (FMI) in all weight status groups, suggesting that MVPA may protect against higher adiposity. Sedentary behavior and diet quality were associated with adiposity only in children with obesity at baseline; neither sedentary behavior nor diet quality was associated with FMI for children with overweight.

Cross-sectional and longitudinal associations between the 24-hour movement behaviours, including muscle and bone strengthening activity, with bone and lean mass from childhood to adolescence

BACKGROUND

This study aimed to assess whether moderate-to-vigorous physical activity (MVPA), sport and exercise as a proxy measure of muscle and bone strengthening activity, sedentary behaviour, and sleep were associated with total-body-less-head (TBLH) bone mineral content (BMC) and TBLH lean mass cross-sectionally and longitudinally from age 6 to 9 years and age 9 to 11 years to age 15 to 17 years.

METHODS

We used longitudinal data from a population sample of Finnish children from the Physical Activity and Nutrition in Children study (age 6 to 9 years: n = 478, 229 females; age 9 to 11 years: n = 384, 197 females; age 15 to 17 years: n = 222, 103 females). Linear regression analysed the cross-sectional and longitudinal associations between accelerometer-assessed MVPA, sedentary time and sleep, and questionnaire-assessed sport and exercise participation and screen time with dual-energy X-ray absorptiometry-assessed TBLH BMC and lean mass.

RESULTS

In females, MVPA at age 6 to 9 years was positively associated with TBLH BMC at age 15 to 17 years (β = 0.008, p = 0.010). Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (β = 0.020, p = 0.002) and lean mass (β = 0.343, p = 0.040) at age 15 to 17 years. MVPA at age 9 to 11 years was positively associated with TBLH lean mass (β = 0.272, p = 0.004) at age 15 to 17 years. In males, sleep at age 6 to 9 years was positively associated with TBLH lean mass (β = 0.382, p = 0.003) at age 15 to 17 years. Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (β = 0.027, p = 0.012) and lean mass (β = 0.721, p < 0.001) at age 15 to 17 years.

CONCLUSIONS

Promoting engagement in the 24-hour movement behaviours in childhood, particularly sport and exercise to strengthen muscle and bone, is important in supporting bone and lean mass development in adolescence.

TRIAL REGISTRATION

NCT01803776; first trial registration date: 04/03/2013.

Appendicular lean mass index changes in patients with Duchenne muscular dystrophy and Becker muscular dystrophy

INTRODUCTION

Mutations in the 79 exons of the dystrophin gene result in muscle wasting and weakness of varying clinical severity, ranging from severe/typical Duchenne muscular dystrophy (DMD) to intermediate DMD and mild Becker muscular dystrophy (BMD), depending on the frameshift of the mutation. We previously reported that males with DMD have progressively declining appendicular lean mass (ALM) and ALM index (ALMI) with age and worsening functional motor ability compared with healthy controls. These indices have not been studied in patients with intermediate DMD and BMD phenotypes and across DMD genotypes. In this study, we compared age-related trajectories of ALM and ALMI of patients who had (1) BMD without functional mobility deficits with patients who had DMD at different stages of disease and healthy controls; (2) a DMD intermediate phenotype with patients who had a typical DMD phenotype; and (3) DMD categorized by genotype.

METHODS

We conducted a retrospective review of ALM and ALMI data from 499 patients (ages 5-23 years) with DMD (466 typical and 33 intermediate) and 46 patients (ages 5-21 years) with BMD (without functional mobility deficits and functional mobility score of 1). Patients were grouped according to age reflecting disease stage (ages 5 to <7, 7 to <10, 10 to <14, and 14 to <20 years) and genotype (mutations in exons 1-30, 31-44, 45-62, and 63-79).

RESULTS

ALM and ALMI trajectories of patients with BMD paralleled those of healthy controls until adolescence, in contrast to patients with DMD. ALMI Z-scores of patients with BMD remained within ±2 SD without decline while those of patients with DMD fell below -2 SD around age 12 years. Patients with BMD had increasing ALM and ALMI with age, with peak accrual between ages 10 to <14 years. ALMI declined after age 14 years for those with intermediate DMD compared with 10 years for patients with typical DMD. Patients with mutations in exons 63-79 had a greater decline in ALMI as compared with those with other genotypes after age 10 years.

CONCLUSIONS

Age-related changes in ALMI in patients with BMD and intermediate DMD differ from those with typical DMD, reflecting their clinical phenotypes. ALM and ALMI should be further studied in patients with BMD and DMD subtypes for their potential value as surrogate markers to characterize the severity of BMD and DMD and inform clinical care decisions and clinical trial designs.

Adiposity is not associated with caries among youth in the United States

BACKGROUND

Body mass index has been traditionally used to determine the nutritional status of children in studies on obesity and caries. Imaging methods provide a superior assessment of body fat. This study investigated the relationship between measures of adiposity and caries in permanent teeth in children and adolescents.

METHODS

The analysis included 5,694 participants in the National Health and Nutrition Examination Survey from 2011 through 2018, aged 8 through 19 years. The body fat percentage (BF%) and fat mass index (FMI) were determined from whole-body dual-energy x-ray absorptiometry scans. Excess adiposity was defined as a sex- and age-specific value at or above the 75th percentile according to the US reference standards for BF% or FMI. Caries was measured with the decayed teeth and decayed, missing, and filled teeth indexes; prevalence of untreated dentin caries; and lifetime caries prevalence. The associations between adiposity and caries were tested in confounding variables-adjusted regression models.

RESULTS

The FMI score was associated with the decayed, missing, and filled teeth score (rate ratio, 1.03; 95% CI, 1.01 to 1.05) and lifetime caries prevalence (odds ratio, 1.06; 95% CI, 1.03 to 1.08), but the associations attenuated after adjustment for confounding variables. Neither the BF% score nor the presence of excess adiposity, defined according to the BF% or FMI reference standards, were associated with caries.

CONCLUSION

The authors found no association between measures of adiposity and caries among US children and adolescents.

PRACTICAL IMPLICATIONS

Caries is a multifactorial disease, and any observed association between obesity and caries is most likely due to the shared determinants and risk factors of both conditions.

Reference values for body composition in healthy urban Mexican children and adolescents

INTRODUCTION

Given the increasing incidence of chronic degenerative diseases related to changes in tissues, the availability of diagnostic tools with greater accuracy in the estimation of body composition (BC) has become necessary. Interpreting the BC values of individuals requires reference data obtained from a healthy population with the same ethnicity, to identify individuals at risk for the development of negative health outcomes.

OBJECTIVE

Generate reference values (RV) of body composition (BC) for Mexican children and adolescents.

METHODS

This was an urban-population-based cross-sectional study of healthy Mexican children and adolescents. BC estimations by anthropometry, multifrequency bioimpedance analysis (MF-BIA) and dual-energy X-ray absorptiometry (DXA) where used to create sex- and age-specific RV by means of generalized additive models for location, scale and shape (GAMLSS).

RESULTS

We assessed 2104 subjects, and after confirming a clinically and metabolically healthy status, we measured 1659 subjects aged 5-20 years, [806 females (49%) and 853 males (51%)] by anthropometry, MF-BIA and DXA to create sex- and age- smoothed reference centiles, lambda (L), mu (M), and sigma (S) values. We also built sex- and age-smoothed graphic curves for each variable of interest.

CONCLUSIONS

We present valid RV and curves for BC variables estimated by anthropometry, MF-BIA and DXA from clinically and metabolically healthy urban Mexican children and adolescents. These RV are different from those reported for other populations, and therefore, should be used for clinical and research purposes involving urban Mexican children and adolescents.

Differential associations between television viewing, computer use, and adiposity by age, gender, and race/ethnicity in United States youth: A cross-sectional NHANES analysis

BACKGROUND

Time spent on screens and adiposity change rapidly from childhood to adolescence, with differences by gender and race/ethnicity.

OBJECTIVE

Apply time-varying effect models (TVEMs) to a nationally representative sample of youth to identify the age ranges when the cross-sectional associations between television viewing, computer use, and adiposity are significant.

METHODS

Data from 8 to 15-year-olds (n = 3593) from the National Health and Nutrition Examination Survey (2011-2018) were extracted. TVEMs estimated the associations between television viewing, computer use, and fat mass index as dynamic functions of the participants' age, stratified by gender and race/ethnicity.

RESULTS

TVEMs revealed age-specific statistically significant associations that differed by gender and race/ethnicity. Notably, computer use was related to higher adiposity in non-Hispanic White females aged 9.3-11.4 years (slope β-range: 0.1-0.2) and in non-Hispanic Black females older than 14.8 years (β-range: 0.1-0.5). In males, these age windows were 13.5-15.0 years (non-Hispanic White, β-range: 0.1-0.2), 11.4-13.0 years (non-Hispanic Black, β-range: 0.1-0.14), and older than 13.0 years (Hispanic, β-range: 0.1-0.4).

CONCLUSIONS

More research during the specific age ranges in the demographic subgroups identified here could increase our understanding of tailored interventions in youth.

Reference ranges for body composition indices by dual energy X-ray absorptiometry from the Bone Mineral Density in Childhood Study Cohort

BACKGROUND

Body composition assessment aids evaluation of energy stores and the impact of diseases and interventions on child growth. Current United States pediatric reference ranges from the National Health and Nutrition Examination Survey (NHANES) include 20% of children with obesity, body mass index of ≥95th percentile.

OBJECTIVES

This study aimed to develop dual energy X-ray absorptiometry (DXA) based reference ranges in a diverse cohort with low-obesity prevalence from the Bone Mineral Density in Childhood Study (BMDCS).

METHODS

This is a secondary analysis of a longitudinal, prospective, observational cohort. Healthy children (height and BMI within 3rd to 97th percentiles, ages 5-19 y at enrollment), from 5 United States centers were measured annually for ≤7 visits. Whole body scans were acquired using Hologic scanners. A subsample underwent repeat measurements to determine precision. We generated reference ranges for appendicular and total lean soft tissue mass index (LSTM Index), fat mass index (FMI), and other body composition measures. Resulting curves were compared to NHANES and across subgroups. Sex and age-specific equations were developed to adjust body composition Z-scores for height Z score.

RESULTS

We obtained 9846 scans of 2011 participants (51% female, 22% Black, 17% Hispanic, 48% White, 7% Asian/Pacific Islander, and 6% with obesity). Precision (percent coefficient of variation) ranged from 0.7% to 1.96%. Median and-2 standard deviation curves for BMDCS and NHANES were similar, but NHANES +2 standard deviation LSTM Index and FMI curves were distinctly greater than the respective BMDCS curves. Subgroup differences were more extreme for appendicular LSTM Index-Z (mean ± SD: Asian -0.52 ± 0.93 compared with Black 0.77 ± 0.87) than for FMI-Z (Hispanic 0.29 ± 0.98 compared with Black -0.14 ± 1.1) and were smaller for Z-scores adjusted for height Z-score.

CONCLUSIONS

These reference ranges add to sparse normative data regarding body composition in children and adolescents and are based on a cohort with an obesity prevalence similar to current BMI charts. Awareness of subgroup differences aids in interpreting results.

Examining Whether Genetic Variants Moderate the Skeletal Effects of Selective Serotonin Reuptake Inhibitors in Older Adolescents and Young Adults

Objective: To examine whether serotonin (5-HT) related genetic variants moderate the effects of selective serotonin reuptake inhibitors (SSRIs) on skeletal outcomes. Methods: Trabecular bone mineral density (BMD) at the radius, lumbar spine (LS) BMD, total body less head (TBLH) bone mineral content (BMC) and markers of bone metabolism (osteocalcin, C-terminal telopeptide of type I collagen [CTX-1], and bone specific alkaline phosphatase to CTX-1 ratio) were examined in an observational study, enrolling 15- to 20-year-old participants, unmedicated or within a month of SSRI initiation. Variants in HTR1A (rs6295), HTR1B (rs6296), HTR1D (rs6300), HTR2A (rs6311 and rs6314), HTR2B (rs6736017), and the serotonin transporter intron 2 variable number tandem repeat (STin2 VNTR) were genotyped. Linear mixed-effects regression analysis examined associations between SSRI use, genetic variants, and skeletal outcomes. Results: After adjusting for relevant covariates, rs6295 CC and GC genotypes in 262 participants (60% female, mean ± SD age = 18.9 ± 1.6 years) were significantly associated with higher LS BMD compared to the GG genotype. Rs6311 GG SSRI users had greater LS BMD compared to nonusers (β = 0.18, p = <0.0001). Female SSRI users with the combination of rs6295 CC+GC and rs6311 GG genotypes had greater LS BMD than female SSRI nonusers (β = 0.29, p < 0.0001). SSRI users with the rs6295 GG genotype had higher trabecular BMD compared to nonusers (β = 3.60, p = 0.05). No significant interactions were found for TBLH BMC or bone turnover markers. After correcting for multiple comparisons, none of the results retained significance. Conclusions: In older adolescents and young adults, HTR1A (rs6295) and HTR2A (rs6311) variants may moderate the effect of SSRIs on BMD. Sex differences may exist and require further examination. Further research with larger sample sizes is needed to confirm our preliminary findings. Clinical Trial Registration: clinicaltrials.gov NCT02147184.

Prenatal and childhood exposure to per-/polyfluoroalkyl substances (PFASs) and its associations with childhood overweight and/or obesity: a systematic review with meta-analyses

BACKGROUND

Per-/polyfluoroalkyl substances (PFASs) are persistent organic pollutants and suspected endocrine disruptors.

OBJECTIVE

The aim of this work was to conduct a systematic review with meta-analysis to summarise the associations between prenatal or childhood exposure to PFASs and childhood overweight/obesity.

METHODS

The search was performed on the bibliographic databases PubMed and Embase with text strings containing terms related to prenatal, breastfeeding, childhood, overweight, obesity, and PFASs. Only papers describing a biomonitoring study in pregnant women or in children up to 18 years that assessed body mass index (BMI), waist circumference (WC), or fat mass in children were included. When the estimates of the association between a PFAS and an outcome were reported from at least 3 studies, a meta-analysis was conducted; moreover, to correctly compare the studies, we developed a method to convert the different effect estimates and made them comparable each other. Meta-analyses were performed also stratifying by sex and age, and sensitivity analyses were also performed.

RESULTS

In total, 484 and 779 articles were retrieved from PubMed and Embase, respectively, resulting in a total of 826 articles after merging duplicates. The papers included in this systematic review were 49: 26 evaluating prenatal exposure to PFASs, 17 childhood exposure, and 6 both. Considering a qualitative evaluation, results were conflicting, with positive, negative, and null associations. 30 papers were included in meta-analyses (19 prenatal, 7 children, and 4 both). Positive associations were evidenced between prenatal PFNA and BMI, between PFOA and BMI in children who were more than 3 years, and between prenatal PFNA and WC. Negative associations were found between prenatal PFOS and BMI in children who were 3 or less years, and between PFHxS and risk of overweight. Relatively more consistent negative associations were evidenced between childhood exposure to three PFASs (PFOA, PFOS, and PFNA) and BMI, in particular PFOS in boys. However, heterogeneity among studies was high.

CONCLUSION

Even though heterogeneous across studies, the pooled evidence suggests possible associations, mostly positive, between prenatal exposure to some PFASs and childhood BMI/WC; and relatively stronger evidence for negative associations between childhood exposure to PFASs and childhood BMI.

Body Composition Measures and N-terminal pro-B-type Natriuretic Peptide (NT-pro-BNP) in US Adults

BACKGROUND

The associations of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) with dual energy x-ray absorptiometry (DEXA)-derived measures of body mass and composition are largely unknown.

METHODS

We included participants aged ≥20 years from the 1999-2004 National Health and Nutrition Examination Survey with NT-pro-BNP and DEXA-derived body composition (fat and lean mass) measures. We used linear and logistic regression to characterize the associations of measures of body mass and composition (body mass index [BMI], waist circumference [WC], fat mass, and lean mass) with NT-pro-BNP, adjusting for cardiovascular risk factors.

RESULTS

We conducted sex-specific analyses among 9134 adults without cardiovascular disease (mean age 44.4 years, 50.8% women, and 72% White adults). The adjusted mean NT-proBNP values were lowest in the highest quartiles of BMI, WC, fat mass, and lean mass. There were large adjusted absolute differences in NT-pro-BNP between the highest and lowest quartiles of DEXA-derived lean mass, -6.26 pg/mL (95% confidence interval [CI], -8.99 to -3.52) among men and -22.96 pg/mL (95% CI, -26.83 to -19.09) among women. Lean mass exhibited a strong inverse association with elevated NT-pro-BNP ≥ 81.4 pg/mL (highest quartile) - odds ratio (OR) 0.58 (95% CI, 0.39-0.86) in men and OR 0.59 (95% CI, 0.47-0.73) in women for highest lean mass quartile vs. lowest quartile. Further adjustment for fat mass, BMI, or WC did not appreciably alter the inverse association of lean mass with NT-pro-BNP.

CONCLUSIONS

In a national sample of US adults, lean mass was inversely associated with NT-pro-BNP.

Associations of weight and body composition at birth with body composition and cardiometabolic markers in children aged 10 y: the Ethiopian infant anthropometry and body composition birth cohort study

BACKGROUND

Although birth weight (BW) has been associated with later cardiovascular disease and type 2 diabetes, the role of birth fat mass (BFM) and birth fat-free mass (BFFM) on cardiometabolic health is unclear.

OBJECTIVES

To examine associations of BW, BFM, and BFFM with later anthropometry, body composition, abdominal fat, and cardiometabolic markers.

METHODS

Birth cohort data on standardized exposure variables (BW, BFM, and BFFM) and follow-up information at age 10 y on anthropometry, body composition, abdominal fat, and cardiometabolic markers were included. A linear regression analysis was used to assess associations of exposures with outcome variables, adjusting for maternal and child characteristics at birth and current body size in separate models.

RESULTS

Among 353 children, mean (SD) age was 9.8 (1.0) y, and 51.5% were boys. In the fully adjusted model, 1-SD higher BW and BFFM were associated with 0.81 cm (95% CI: 0.21, 1.41 cm) and 1.25 cm (95% CI: 0.64, 1.85 cm) greater height at 10 y, respectively. The 1-SD higher BW and BFM were associated with 0.32 kg/m2 (95% CI: 0.14, 0.51 kg/m2) and 0.42 kg/m2 (95% CI: 0.25, 0.59 kg/m2) greater fat mass index at 10 y, respectively. In addition, 1-SD higher BW and BFFM were associated with 0.22 kg/m2 (95% CI: 0.09, 0.34 kg/m2) greater FFM index, whereas a 1-SD greater BFM was associated with a 0.05 cm greater subcutaneous adipose tissue (95% CI: 0.01, 0.11 cm). Furthermore, 1-SD higher BW and BFFM were associated with 10.3% (95% CI: 1.4%, 20.0%) and 8.3% (95% CI: -0.5%, 17.9%) greater insulin, respectively. Similarly, 1-SD higher BW and BFFM were associated with 10.0% (95% CI: 0.9%, 20.0%) and 8.5% (95% CI: -0.6%, 18.5%) greater homeostasis model assessment of insulin resistance, respectively.

CONCLUSIONS

BW and BFFM rather than BFM are predictors of height and FFM index at 10 y. Children with higher BW and BFFM showed higher insulin concentrations and homeostasis model assessment of insulin resistance at 10 y of age. This trial was registered at ISRCTN as ISRCTN46718296.

Cool executive functions and their association with body mass & fatness and the FTO gene in school-aged children

The FTO gene rs9936909 polymorphism is one of the well-documented single nucleotide polymorphisms in the context of increased risk of obesity, including in children. Few studies have tested the association of the FTO gene with cognitive functions. Deficits of "cool" executive functions (EFs) are considered a potential risk factor for excessive weight. The aims of our study were to investigate whether cool EFs are associated with the Body Mass Index, the Fat Mass Index and the risk of excess body mass and overfatness in neurotypically school-aged children, and whether the FTO gene polymorphism is involved in development of this possible association. The sample consisted of 553 children aged 6-12 years old. A body composition analysis, a neuropsychological assessment of EFs, and FTO polymorphism genotyping were performed in the children studied. The study found a significant association of an interference effect in theStroop Color-Word Interference Task and the risk of excessive body fatness, but not excessive body mass. There were no explicit associations between the FTO genotype and EFs deficits. Environmental factors, and particularly low maternal education, appeared to be the strongest contributors to the increased risk of obesity.

Adherence to a Mediterranean Diet, Body Composition and Energy Expenditure in Outpatients Adolescents Diagnosed with Anorexia Nervosa: A Pilot Study

Weight restoration is the primary goal of treatment for patients with Anorexia Nervosa (AN). This observational pilot study aims to describe adherence to the Mediterranean Diet (MD) and the consequent process of weight and functional recovery in outpatient adolescents diagnosed with AN. Eight patients with a median age of 15.1 (14.0-17.1) years were seen at baseline and after six months. Anthropometrics, body composition, and resting energy expenditure (REE) were assessed. The KIDMED questionnaire, the 24 h recall, and a quantitative food frequency questionnaire were used to evaluate adherence to the MD. The median KIDMED score increased from 5.5 (T0) to 10 (T1), which was not significant. Intakes of grams of carbohydrates, lipids, mono-unsaturated fatty acids, and fiber increased (p = 0.012, p = 0.036, p = 0.036, p = 0.025). Weight significantly increased (p = 0.012) as well as lean body mass (p = 0.036), with a resulting improvement of the REE (p = 0.012). No association between anthropometrics and body composition and the KIDMED score was found. The MD could represent an optimal dietary pattern for weight gain and nutritional restoration in patients with AN, and it could lead to an improvement in body composition and resting energy expenditure.

The association of intrauterine and postnatal growth patterns and nutritional status with toddler body composition

BACKGROUND

Growth patterns may be indicative of underlying changes in body composition. However, few studies have assessed the association of growth and body composition in poorly resourced regions experiencing the double-burden of malnutrition exists. Thus, the aims of this study were to investigate the association of intrauterine and postnatal growth patterns with infant body composition at 2 years in a middle-income country.

METHODS

Participants were from the International Atomic Energy Agency Multicentre Body Composition Reference study. Fat mass (FM), fat free mass (FFM), Fat mass index (FMI), fat free mass index (FFMI), and percentage fat mass (%FM) were measured in 113 infants (56 boys and 57 girls), from Soweto, South Africa, using deuterium dilution from 3 to 24 months. Birthweight categories were classified using the INTERGROWTH-21 standards as small (SGA), appropriate (AGA), and large-for gestational age (LGA). Stunting (> -2 SDS) was defined using the WHO child growth standards. Birthweight z-score, conditional relative weight and conditional length at 12 and 24 mo were regressed on body composition at 24 mo.

RESULTS

There were no sex differences in FM, FFM, FMI and FFMI between 3 and 24 mo. SGA and AGA both had significantly higher %FM than LGA at 12 mo. LGA had higher FM at 24 mo. Children with stunting had lower FM (Mean = 1.94, 95% CI; 1.63-2.31) and FFM (Mean = 5.91, 95% CI; 5.58-6.26) at 12 mo than non-stunting, while the reverse was true for FFMI (Mean = 13.3, 95% CI; 12.5-14.2) at 6 mo. Birthweight and conditionals explained over 70% of the variance in FM. CRW at both 12 and 24 mo was positively associated with FM and FMI. CRW at 12 mo was also positively associated with FMI, while CH at 24 mo was negatively associated with both FFMI and FMI in boys.

CONCLUSION

Both LGA and SGA were associated with higher body fat suggesting that both are disadvantaged nutritional states, likely to increase the risk of obesity. Growth patterns through infancy and toddler period (1-2 years) are indicative of body fat, while growth patterns beyond infancy are less indicative of fat-free mass.

The association between the timing, intensity and magnitude of adolescent growth and body composition in early adulthood

OBJECTIVES

There's paucity of longitudinal studies assessing the role of adolescent growth on adult body composition in developing countries. The aims of this study were to assess the association between adolescent change in height, weight and BMI and early adult height, weight, body fat and lean mass.

METHODS

Magnitude, timing and intensity of height, weight and BMI growth were modelled for participants from the Birth to Thirty (Bt30) cohort (7-23 years). Early adult height, weight, BMI and DXA-derived body composition were obtained 1881 black participants (21-24 years). Linear regression analyses were used to assess associations.

RESULTS

Adolescents with an earlier onset of puberty were heavier in childhood and had an earlier timing and faster weight gain velocity in late adolescence. The intensity of adolescent weight gain was positively associated with adult BMI and fat mass index (FMI) in females. Early timing of adolescent BMI gain was associated with increased weight and BMI in adult females and FMI in adult males. Achieving peak weight velocity around age at peak height velocity was associated with lower BMI and fat mass in both sexes.

CONCLUSION

This study confirms the adverse consequences of excessive weight gain prior to puberty, which is associated with an earlier and faster resurgence in weight gain velocity in early adulthood. Factors that contribute to an asynchronous timing of ages of peak weight and peak height velocities may accentuate the risk of adult obesity.

Accuracy and capability of tri-ponderal mass index in assessing cardio-metabolic risk factors in Chinese children and adolescents aged 3 to 17 years, compared with body mass index

BACKGROUND

Tri-ponderal mass index (TMI) has been reported to be a more accurate estimate of body fat than body mass index (BMI). This study aims to compare the effectiveness of TMI and BMI in identifying hypertension, dyslipidemia, impaired fasting glucose (IFG), abdominal obesity, and clustered cardio-metabolic risk factors (CMRFs) in 3- to 17-year-old children.

METHODS

A total of 1587 children aged 3 to 17 years were included. Logistic regression was used to evaluate correlations between BMI and TMI. Area under the curves (AUCs) were used to compare discriminative capability among indicators. BMI was converted to BMI- z scores, and accuracy was compared by false-positive rate, false-negative rate, and total misclassification rate.

RESULTS

Among children aged 3 to 17 years, the mean TMI was 13.57 ± 2.50 kg/m 3 for boys and 13.3 ± 2.33 kg/m 3 for girls. Odds ratios (ORs) of TMI for hypertension, dyslipidemia, abdominal obesity, and clustered CMRFs ranged from 1.13 to 3.15, higher than BMI, whose ORs ranged from 1.08 to 2.98. AUCs showed similar ability of TMI (AUC: 0.83) and BMI (AUC: 0.85) in identifying clustered CMRFs. For abdominal obesity and hypertension, the AUC of TMI was 0.92 and 0.64, respectively, which was significantly better than that of BMI, 0.85 and 0.61. AUCs of TMI for dyslipidemia and IFG were 0.58 and 0.49. When 85th and 95th of TMI were set as thresholds, total misclassification rates of TMI for clustered CMRFs ranged from 6.5% to 16.4%, which was not significantly different from that of BMI- z scores standardized according to World Health Organization criteria.

CONCLUSIONS

TMI was found to have equal or even better effectiveness in comparison with BMI in identifying hypertension, abdominal obesity, and clustered CMRFs TMI was more stable than BMI in 3- to 17-year-old children, while it failed to identify dyslipidemia and IFG. It is worth considering the use of TMI for screening CMRFs in children and adolescents.

Associations of urinary metabolite concentrations of phthalates and phthalate replacements with body composition from mid-childhood to early adolescence

BACKGROUND

Phthalates may adversely influence body composition by lowering anabolic hormones and activating peroxisome-proliferator activated receptor gamma. However, data are limited in adolescence when body mass distributions rapidly change and bone accrual peaks. Also, potential health effects of certain phthalate/replacements [e.g., di-2-ethylhexyl terephthalate (DEHTP)] have not been well studied.

METHODS

Among 579 children in the Project Viva cohort, we used linear regression to evaluate associations of urinary concentrations of 19 phthalate/replacement metabolites from mid-childhood (median: 7.6 years; 2007-2010) with annualized change in areal bone mineral density (aBMD) and lean, total fat, and truncal fat mass as measured by dual-energy X-ray absorptiometry between mid-childhood and early adolescence (median: 12.8 years). We used quantile g-computation to assess associations of the overall chemical mixture with body composition. We adjusted for sociodemographics and tested for sex-specific associations.

RESULTS

Urinary concentrations were highest for mono-2-ethyl-5-carboxypentyl phthalate [median (IQR): 46.7 (69.1) ng/mL]. We detected metabolites of most replacement phthalates in a relatively small number of participants [e.g., 28% for mono-2-ethyl-5-hydrohexyl terephthalate (MEHHTP; metabolite of DEHTP)]. Detectable (vs. non-detectable) MEHHTP was associated with less bone and greater fat accrual in males and greater bone and lean mass accrual in females [e.g., change in aBMD Z-score/year (95% CI): -0.049 (-0.085, -0.013) in males versus 0.042 (0.007, 0.076) in females; pinteraction<0.01]. Children with higher concentrations of mono-oxo-isononyl phthalate and mono-3-carboxypropyl phthalate (MCPP) had greater bone accrual. Males with higher concentrations of MCPP and mono-carboxynonyl phthalate had greater accrual of lean mass. Other phthalate/replacement biomarkers, and their mixtures, were not associated with longitudinal changes in body composition.

CONCLUSIONS

Concentrations of select phthalate/replacement metabolites in mid-childhood were associated with changes in body composition through early adolescence. As use of phthalate replacements such as DEHTP may be increasing, further investigation can help better understand the potential effects of early-life exposures.

The association between hydration status and body composition in healthy children and adolescents

OBJECTIVES

Children 10-20 years old in the US are currently obese, showing suboptimal hydration as 60% fail to meet the US Dietary Reference Intakes for water. Studies have shown a significant inverse association between hydration status and body composition in children, although most failed to use the Dual-X-Ray Absorptiometry Scan (DEXA), the gold standard for body composition. Limited studies used an objective marker to measure hydration, such as urine specific gravity (USG) from a 24-h urine collection. Therefore, this study aimed to examine the association between hydration status (measured from USG in a 24-h urine sample and assessed from three 24-h dietary recalls) and body fat % and lean mass (assessed from a DEXA scan) in children (10-13 years, n=34) and adolescents (18-20 years, n=34).

METHODS

Body composition was measured using DEXA, total water intake (mL/d) was assessed from three 24-h dietary recalls and analyzed using the Nutrition Data System for Research (NDSR). Hydration status was objectively measured using USG via 24-h urine collection.

RESULTS

Overall body fat % was 31.7 ± 7.31, total water intake was 1746 ± 762.0 mL/d, and USG score was 1.020 ± 0.011 uG. Linear regressions showed significance between total water intake and lean mass (B=12.2, p<0.05). Logistic regressions showed no significant association between body composition and USG and total water intake.

CONCLUSIONS

Findings showed total water intake was significantly associated with lean mass. Future research should be conducted to explore other objective markers of hydration and with a larger sample.

The Effects of 5 Years of Growth Hormone Treatment on Growth and Body Composition in Patients with Temple Syndrome

INTRODUCTION

Temple syndrome (TS14) is a rare imprinting disorder caused by maternal uniparental disomy of chromosome 14, paternal deletion of 14q32.2, or an isolated methylation defect. Most patients with TS14 develop precocious puberty. Some patients with TS14 are treated with growth hormone (GH). However, evidence for the effectiveness of GH treatment in patients with TS14 is limited.

METHODS

This study describes the effect of GH treatment in 13 children and provides a subgroup analysis of 5 prepubertal children with TS14. We studied height, weight, body composition by dual-energy X-ray absorptiometry, resting energy expenditure (REE), and laboratory parameters during 5 years of GH treatment.

RESULTS

In the entire group, mean (95% CI) height SDS increased significantly during 5 years of GH treatment from -1.78 (-2.52; -1.04) to 0.11 (-0.66; 0.87). Fat mass percentage SDS decreased significantly during the first year of GH, and lean body mass (LBM) SDS and LBM index increased significantly during 5 years of treatment. IGF-1 and IGF-BP3 levels rose rapidly during GH treatment, and the IGF-1/IGF-BP3 molar ratio remained relatively low. Thyroid hormone levels, fasting serum glucose, and insulin levels remained normal. In the prepubertal group, median (interquartile range [IQR]) height SDS, LBM SDS, and LBM index also increased. REE was normal at start and did not change during 1 year of treatment. Five patients reached adult height and their median (IQR) height SDS was 0.67 (-1.83; -0.01).

CONCLUSION

GH treatment in patients with TS14 normalizes height SDS and improves body composition. There were no adverse effects or safety concerns during GH treatment.

Overfat cutoffs and the optimal combination of body fat indices for detecting cardiometabolic risk among school-aged children

OBJECTIVE

This study aimed to develop cutoffs and the optimal combination for body fat indices for screening cardiometabolic risk (CMR) among the pediatric population.

METHODS

This cross-sectional study consisted of 8710 (50.3% boys) Chinese children aged 6 to 18 years. Body fat indices, including fat mass index (FMI), body fat percentage, trunk to leg fat ratio (TLR), and android to gynoid fat ratio, were derived from dual-energy x-ray absorptiometry scans. The area under the receiver operating characteristic curve was used to determine the best combination and optimal cutoffs of body fat indices to identify CMR.

RESULTS

Compared with anthropometry-based obesity measures, i.e., BMI and waist circumference, the FMI + TLR combination presented statistically higher area under the receiver operating characteristic curve values for discriminating CMR and its clustering. The optimal overfat cutoffs of FMI and TLR were respectively determined at the 75th percentile in boys and at the 80th percentile of FMI and the 75th percentile of TLR in girls. Moreover, simplified thresholds derived from age-group-merged cutoffs showed similar performance as optimal cutoffs in detecting CMR.

CONCLUSIONS

Both the optimal and simplified overfat cutoffs were provided for the Chinese pediatric population. The use of FMI and TLR together allows for adequate screening of CMR and its clustering.

Physical activity volume and intensity distribution in relation to bone, lean and fat mass in children

Considering physical activity (PA) volume and intensity may provide novel insights into the relationships of PA with bone, lean, and fat mass. This study aimed to assess the associations of PA volume, PA intensity distribution, including moderate-to-vigorous PA (MVPA) with total-body-less-head bone mineral content (BMC), lean, and fat mass in children. A population sample of 290 Finnish children (158 females) aged 9-11 years from the Physical Activity and Nutrition in Children (PANIC) Study was studied. PA, including MVPA, was assessed with a combined heart rate and movement sensor, and the uniaxial acceleration was used to calculate average-acceleration (a proxy metric for PA volume) and intensity-gradient (reflective of PA intensity distribution). Linear regression analyzed the associations of PA volume, PA intensity and MVPA with BMC, lean mass, and fat mass assessed by dual-energy X-ray absorptiometry. PA volume was positively associated with BMC in females (unstandardised regression coefficient [ß] = 0.26) and males (ß = 0.47), and positively associated with lean (ß = 7.33) and negatively associated with fat mass in males (ß = -20.62). PA intensity was negatively associated with BMC in males (ß = -0.13). MVPA was positively associated with lean mass in females and males (ß = 0.007 to 0.012), and negatively associated with fat mass in females and males (ß = -0.030 to -0.029). PA volume may be important for improving BMC in females and males, and increasing lean and reducing fat mass in males, whereas MVPA may be important for favorable lean and fat outcomes in both sexes.

Body composition and functional correlates of CF youth experiencing pulmonary exacerbation and recovery

BACKGROUND

Youth with cystic fibrosis (CF) and pulmonary exacerbation (PEx) often experience weight loss, then rapid weight gain. Little is known about body composition and its relationship to functional outcomes during this critical period.

METHODS

Twenty CF youth experiencing PEx were assessed on the day following admission and 7-17 days later at discharge for body mass index (BMI), fat mass index (FMI), lean mass index (LMI), skeletal muscle mass index (SMMI), and functional measures: percent predicted forced expiratory volume in 1 second (FEV1) (ppFEV1), maximal inspiratory and expiratory pressures (MIPs and MEPs), and handgrip strength (HGS). Changes from admission to discharge and correlations among body composition indices and functional measures at both times are reported.

RESULTS

Upon admission, participant BMI percentile and ppFEV1 varied from 2 to 97 and 29 to 113, respectively. Thirteen had an LMI below the 25th percentile and nine had a percent body fat above the 75th percentile. BMI and FMI increased significantly (p = 0.03, 0.003) during hospitalization. LMI and SMMI did not change. FEV1 and MIPS increased (p = 0.0003, 0.007), independent of weight gain, during treatment. HGS did not improve.

CONCLUSIONS

Many youth with CF, independent of BMI, frequently carried a small muscle mass and disproportionate fat at the time of PEx. During hospital treatment, weight gain largely represented fat deposition; muscle mass and strength did not improve. A need for trials of interventions designed to augment muscle mass and function, and limit fat mass accretion, at the time of PEx is suggested by these observations.

The relationship between obesity and bone mineral density in children and adolescents: analysis of the National Health and Nutrition Examination Survey

Childhood and puberty are important period for the skeleton grows. Fat mass, especially visceral adipose tissue, was negatively correlated with areal bone mineral density in children and adolescents. The present study suggests that fat mass, especially visceral adipose tissue, has a slightly negative association with bone development in children and adolescents.

PURPOSE

This study observed the relationship between fat mass and distribution, and areal bone mineral density (aBMD) in children and adolescents.

METHODS

A retrospective study was conducted on US children and adolescents aged 8-19 years. Whole body (less head) aBMD was evaluated. Height (Ht) adjusted Z-scores for aBMD were calculated.

RESULTS

After controlling for age, gender, race, and lean body mass index (LBMI) Z-score, there were significant negative associations between fat mass index (FMI) Z-score and aBMD Ht-Z-adjusted Z-score (β =  - 0.272, P < 0.001, R2 = 0.033). In the linear regression models with aBMD Ht-Z-adjusted Z-score as the dependent variable, the regression coefficients of android fat mass were - 0.241 (P < 0.05, R2 = 0.002), - 0.473 (P < 0.001, R2 = 0.036), and - 0.474 (P < 0.001, R2 = 0.038) for healthy weight, overweight, and obesity group, respectively. The regression coefficients of visceral adipose tissue (VAT) mass were - 0.218 (P > 0.05, R2 = 0.001), - 2.025 (P < 0.001, R2 = 0.044), and - 1.826 (P < 0.001, R2 = 0.039), and the regression coefficients of subcutaneous adipose tissue (SAT) mass were - 0.467 (P < 0.001, R2 = 0.004), - 0.339 (P < 0.01, R2 = 0.024), and - 0.347 (P < 0.001, R2 = 0.018) for healthy weight, overweight, and obesity group, respectively.

CONCLUSIONS

The present study suggests that fat mass has a slightly negative association with bone development in children and adolescents. Trunk fat accumulation, especially visceral adipose tissue, was correlated with the lower level of aBMD. This association was obvious in overweight and obese children.

Longitudinal changes in juvenile and adolescent body mass indices before, during, and after the COVID-19 lockdown in New Zealand

OBJECTIVE

This study uses longitudinal data from school children in Dunedin, New Zealand, to evaluate impacts of COVID-19 lockdown measures on changes in body mass (BMI, kg/m² ). Impacts are assessed using two non-mutually exclusive hypotheses. The "structured days" hypothesis holds that children tend to alter sleep patterns, reduce activity and increase snacking when not in structured environments. The bidirectional hypothesis proposes that over-weight or obese children are predisposed to further gains in unstructured settings.

METHODS

Juveniles and adolescents (n = 95, 60% female) were recruited from Dunedin schools. Repeated measures analyses assessed variation in intra-individual change in BMI during four periods: P1 (before summer break), P2 (during summer break), P3 (during the COVID-19 lockdown), and P4 (after the lockdown ended). The model also examined if these changes were influenced by participants' sex or body size early in the first period assessed using log-transformed BMI, log-transformed weight, height, or lower leg length.

RESULTS

Repeated measures analyses of per month gains in BMI (kg/m² ) during the four periods revealed consistent period (p ≤ .001), period by sex (p ≤ .010), and period by body size (p ≤ .001) interactions across all four body size proxies. Both sexes experienced the greatest gains during the lockdown (P3), but differed in response to their summer break (P2).

CONCLUSION

Results are mostly consistent with the "structured days" hypothesis, but challenge the bidirectional hypothesis as defined. Further research better characterizing risks of gains in adiposity are needed.

Elevated LDL-C, high blood pressure, and low peak V ˙ O2 associate with platelet mitochondria function in children-The Arkansas Active Kids Study

Purpose: To evaluate the association of platelet (PL) mitochondria respiration with markers of cardiovascular health in children ages 7-10 years. Methods: PL mitochondrial respiration (n = 91) was assessed by high resolution respirometry (HRR): Routine (R) respiration, complex (C) I linked respiration (CI), and maximal uncoupled electron transport capacity of CII (CII_E) were measured. The respiratory control ratio (RCR) was calculated as the ratio of maximal oxidative phosphorylation capacity of CI and CI leak respiration (P_CI/L_CI). Peak V ˙ O₂ (incremental bike test) and body composition (dual-energy X-ray absorptiometry) were measured. Multiple generalized linear regression analysis was used to model the association of measures by HRR with variables of interest: adiposity, low-density lipoprotein (LDL-C) and triglyceride (TG) status (normal vs. elevated) HOMA2-IR, blood pressure status (normal vs. high), and demographics. Results: R and CI-linked respiration positively associated with adiposity, high blood pressure (HBP), and peak V ˙ O₂. R and CI-linked respiration had inverse association with age and elevated LDL-C. CII_E was higher in children with elevated LDL-C (log-β = -0.54, p = 0.010). HBP and peak V ˙ O₂ interacted in relation to RCR (log-β = -0.01, p = 0.028). Specifically, RCR was lowest among children with HBP and low aerobic capacity (i.e., mean peak V ˙ O₂ -1SD). HOMA2-IR did not associate with measures of PL mitochondria respiration. Conclusion: In PL, R and CI-linked mitochondrial respiration directly associate with adiposity, peak V ˙ O₂ and HBP. Elevated LDL-C associates with lower CI-linked respiration which is compensated by increasing CII respiration. PL bioenergetics phenotypes in children associate with whole-body metabolic health status.

Association of cardiometabolic risk factors with insulin resistance in overweight and obese children

INTRODUCTION

Regarding the increased prevalence of obesity among children and adolescents, and the impact of obesity on insulin resistance (IR) and other metabolic disorders, this study was performed to determine the association of cardiometabolic risk factors (CMRFs) with IR in overweight and obese children.

METHOD

In this cross-sectional study 150 overweight and obese children (BMI ≥ 85^th and BMI ≥ 95^th age-sex specific percentile) and adolescents were selected via convenient sampling method from Endocrinology clinic in Karaj; Iran in 2020. Anthropometric indices, lipid profile, fasting blood glucose (FBG), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) were evaluated. IR was defined as HOMA-IR ≥ 2.6. Multivariable linear and logistic regression model was used to assess the association of CMRFs with insulin level and IR respectively.

RESULTS

The mean age of children was 10.37 (± 2.6) years. Fifty-four percent of the participants were girls. IR was increased through increasing age (P < 0.001). In the multivariate logistic regression model, by increasing each unit increment in waist circumference (OR: 1.03, 95% CI: 1.01-1.06), wrist circumference (OR: 1.47, 95% CI: 1.06-2.02) total cholesterol (OR: 1.01, 95% CI: 1.003-1.03) and FBG (OR: 1.11, 95% CI: 1.05-1.18) the odds of IR increased significantly. Moreover, in the adjusted linear regression model, HOMA-IR was associated significantly with waist to height ratio (β: 2.45), and FBG (β: 0.02).

CONCLUSION

There was a significant association between some CMRFS with IR in overweight and obese children.

Associations of cardiorespiratory fitness, body composition, and blood pressure with arterial stiffness in adolescent, young adult, and middle-aged women

Few studies have investigated whether higher cardiorespiratory fitness (CRF) or favourable body composition are related to lower arterial stiffness in women. We therefore investigated the associations of CRF, body fat percentage (BF%), fat free mass index (FFMI), and mean arterial pressure (MAP) with arterial stiffness in 146 women aged 16-58 years. CRF was assessed by a maximal exercise test with respiratory gas analysis either on a cycle ergometer or a treadmill. Aortic pulse wave velocity (PWVao), augmentation index (AIx%), and MAP were assessed by a non-invasive oscillometric device and BF% and FFMI by a bioelectrical impedance or DXA device. CRF was inversely associated with PWVao (β =  - 0.004, 95% CI - 0.005 to - 0.002) and AIx% (β =  - 0.075, 95% CI - 0.102 to - 0.048) and these associations remained similar after adjustment for BF% or MAP, but not after the adjustment for age. FFMI was inversely associated with PWVao (β =  - 0.010, 95% CI - 0.019 to - 0.002) and MAP directly associated with PWVao (β = 0.005, 95% CI 0.003 to 0.006) and AIx% (β = 0.092, 95% CI 0.069 to 0.116) and the associations with PWVao also remained after further adjustments for BF% and age. In conclusion, a higher FFMI and a lower MAP were independently associated with lower arterial stiffness.

Impact of an exercise program in children with inflammatory bowel disease in remission

BACKGROUND

The aim of our study was to investigate the impact of a structured exercise program on bone mineral density (BMD) and body composition parameters in children and adolescents with IBD in remission.

METHODS

Patients were recruited to participate in a 6-month exercise program. Total body less head (TLBH) dual energy X-ray absorptiometry (DXA) was used to measure BMD. The same method was used to assess fat mass (FM) and lean body mass (LBM) at baseline and at the completion of the program.

RESULTS

Based on the baseline and endpoint TBLH DXA measurements, a total of 42 study participants (25 boys; aged 15.3 ± 2.08 years) experienced an increase in BMD (from 0.959 ± 0.023 g/cm² to 0.988 ± 0.025 g/cm², p < 0.001) and LBM (from 37.12 ± 1.43 kg to 38.75 ± 1.61 kg, p = 0.012). Age- and sex-based BMD Z-score increased significantly (from -0.35 ± 0.15 to -0.28 ± 0.17, p = 0.020), whilst LBM Z-score did not significantly change (from -1.78 ± 0.23 to -1.71 ± 1.49, p = 0.908).

CONCLUSIONS

There was a significant improvement in BMD, age- and sex-based BMD Z-score, and LBM amongst study participants. Subgroup analysis showed that patients with CD and male study participants experienced significant improvement in all parameters, whilst patients with UC and IBD-U and female patients experienced improvement solely in BMD.

IMPACT STATEMENT

Children and adolescents with IBD, regardless of disease activity, are under increased risk of secondary osteoporosis and lean body mass deficits. A 6-month home-based structured exercise program leads to a significant improvement in bone mineral density and lean body mass. Exercise therapy should be explored as a potentially adjacent to standard treatment modalities.

Postoperative Osteopathic Manipulative Treatment in Children with Esophageal Atresia: Potential Benefits on the Anthropometric Parameters

Esophageal atresia (EA) is a congenital malformation that affects the normal esophageal development. Surgical treatment, although restoring the integrity of the alimentary tract, may lead to long-term sequelae-like developmental abnormalities and musculoskeletal deformities. We evaluated the effects of osteopathic manipulative treatment (OMT) on the recovery of the range of the right upper limb movement and on the rise of the auxological parameters. A case series of five children affected by type C EA were described. Six OMT sessions were performed over a 4-month period. At each treatment, height, weight, body mass index (BMI) and range of motion (ROM) in elevation of the right upper limb were assessed. OMT was applied to improve scar, larynx, rib cage, and sternum mobility. An average change of 2.3 cm in height and an average increase of 8° in the ROM of the upper limb in the period of study were detected. Additionally, OMT could improve the anthropometric data and the mobility of the right upper limb of children surgically treated for EA. Further studies that evaluate the effectiveness of OMT in post surgical treatment of congenital malformations of the thorax can be considered in the future.

Reference Ranges of Body Composition Using Dual-Energy X-Ray Absorptiometry and Its Relation to Tri-Ponderal Mass Index

Introduction/background Increased body fat is related to obesity and its comorbidities later in life. To determine the amount of body fat in children and adolescents, reference intervals should be applied. Dual-energy X-ray absorptiometry (DXA) is a good tool for accurately measuring body composition. Methodology The body composition reference ranges in Korean children and adolescents were determined using nationally representative cross-sectional data. The performances of the body mass index (BMI) and tri-ponderal mass index (TMI) in measuring body fat were compared using the reference percentiles derived from this analysis. Results A total of 1,661 subjects (891 boys and men and 770 girls and women) were included. Age- and sex-specific percentiles and the corresponding LMS variables for DXA-assessed parameters for the whole body and the trunk were determined. The coefficients of determination of the whole body FM SDS and FMI SDS for the BMI SDS were 0.783 and 0.784, respectively, and those for the TMI SDS were 0.685 and 0.769, respectively. Conclusion Based on the reference values for body composition, the correlation coefficients of TMI for adjusted FM measured by DXA were comparable to those of BMI. TMI estimated body fat levels more accurately than BMI in this study population.

External validation of a prediction model for estimating fat mass in children and adolescents in 19 countries: individual participant data meta-analysis

OBJECTIVE

To evaluate the performance of a UK based prediction model for estimating fat-free mass (and indirectly fat mass) in children and adolescents in non-UK settings.

DESIGN

Individual participant data meta-analysis.

SETTING

19 countries.

PARTICIPANTS

5693 children and adolescents (49.7% boys) aged 4 to 15 years with complete data on the predictors included in the UK based model (weight, height, age, sex, and ethnicity) and on the independently assessed outcome measure (fat-free mass determined by deuterium dilution assessment).

MAIN OUTCOME MEASURES

The outcome of the UK based prediction model was natural log transformed fat-free mass (lnFFM). Predictive performance statistics of R², calibration slope, calibration-in-the-large, and root mean square error were assessed in each of the 19 countries and then pooled through random effects meta-analysis. Calibration plots were also derived for each country, including flexible calibration curves.

RESULTS

The model showed good predictive ability in non-UK populations of children and adolescents, providing R² values of >75% in all countries and >90% in 11 of the 19 countries, and with good calibration (ie, agreement) of observed and predicted values. Root mean square error values (on fat-free mass scale) were <4 kg in 17 of the 19 settings. Pooled values (95% confidence intervals) of R², calibration slope, and calibration-in-the-large were 88.7% (85.9% to 91.4%), 0.98 (0.97 to 1.00), and 0.01 (-0.02 to 0.04), respectively. Heterogeneity was evident in the R² and calibration-in-the-large values across settings, but not in the calibration slope. Model performance did not vary markedly between boys and girls, age, ethnicity, and national income groups. To further improve the accuracy of the predictions, the model equation was recalibrated for the intercept in each setting so that country specific equations are available for future use.

CONCLUSION

The UK based prediction model, which is based on readily available measures, provides predictions of childhood fat-free mass, and hence fat mass, in a range of non-UK settings that explain a large proportion of the variability in observed fat-free mass, and exhibit good calibration performance, especially after recalibration of the intercept for each population. The model demonstrates good generalisability in both low-middle income and high income populations of healthy children and adolescents aged 4-15 years.

Markers of obesity in Danish pediatric liver transplantation recipients

BACKGROUND

Long-time survivors of pediatric liver transplantation have an increased incidence of the metabolic syndrome. Adult recipients have an increased risk of post-transplantation obesity; however, pediatric data are limited.

METHODS

The study included 42 recipients of pediatric liver transplantation in Denmark, transplanted between 1990 and 2014. The study participants were examined with anthropometric measures, dual-energy X-ray scans and blood samples. From the anthropometric measures, body mass index (BMI) and BMI standard deviation score (SDS) were calculated. From the dual-energy X-ray scans, fat percent was assessed, and body fat mass index (BFMI) was calculated.

RESULTS

The median age was 17.4 years (range 4.1-38.9) at the time of the study, and the median time since transplantation was 8.5 years (range 0.4-23.9). The prevalence of overweight and obesity was 31.0% based on BMI SDS (age below 18) and BMI (age 18 and above). When compared to the participants with normal weight, the participants with overweight and obesity had a higher BFMI (9.29 vs 5.57 kg/m² , p < .001) and fat percent (38.35% vs 29.50%, p = .006). They had higher levels of total cholesterol (4.3 vs 3.6 mmol/L, p = .023) and low-density lipoprotein (2.5 vs 1.7, p = .015), and had had longer time since transplantation (15.6 vs 8.5 years respectively, p = .045).

CONCLUSIONS

Long-time survivors of pediatric liver transplantation have a higher BMI or BMI SDS than the general pediatric population. The obesity is characterized by a higher BFMI, fat percent, and cholesterols levels, when compared to recipients without overweight or obesity.

Sex-Specific Changes in Physical Risk Factors for Anterior Cruciate Ligament Injury by Chronological Age and Stages of Growth and Maturation From 8 to 18 Years of Age

OBJECTIVE

To critically assess the literature focused on sex-specific trajectories in physical characteristics associated with anterior cruciate ligament (ACL) injury risk by age and maturational stage.

DATA SOURCES

PubMed, CINAHL, Scopus, and SPORTDiscus databases were searched through December 2021.

STUDY SELECTION

Longitudinal and cross-sectional studies of healthy 8- to 18-year-olds, stratified by sex and age or maturation on ≥1 measure of body composition, lower extremity strength, ACL size, joint laxity, knee-joint geometry, lower extremity alignment, balance, or lower extremity biomechanics were included.

DATA EXTRACTION

Extracted data included study design, participant characteristics, maturational metrics, and outcome measures. We used random-effects meta-analyses to examine sex differences in trajectory over time. For each variable, standardized differences in means between sexes were calculated.

DATA SYNTHESIS

The search yielded 216 primary and 22 secondary articles. Less fat-free mass, leg strength, and power and greater general joint laxity were evident in girls by 8 to 10 years of age and Tanner stage I. Sex differences in body composition, strength, power, general joint laxity, and balance were more evident by 11 to 13 years of age and when transitioning from the prepubertal to pubertal stages. Sex differences in ACL size (smaller in girls), anterior knee laxity and tibiofemoral angle (greater in girls), and higher-risk biomechanics (in girls) were observed at later ages and when transitioning from the pubertal to postpubertal stages. Inconsistent study designs and data reporting limited the number of included studies.

CONCLUSIONS

Critical gaps remain in our knowledge and highlight the need to improve our understanding of the relative timing and tempo of ACL risk factor development.

Gestational and childhood phthalate exposures and adolescent body composition: The HOME study

BACKGROUND

Early life phthalate exposures may disrupt metabolism but results from human studies are inconsistent and few have examined body composition during adolescence. We investigated associations of gestational and childhood urinary phthalate biomarker concentrations with body composition at age 12 years.

METHODS

We used data from 206 mother-child pairs in a prospective pregnancy and birth cohort enrolled in Cincinnati, OH from 2003 to 2006. We measured nine phthalate metabolites in spot urine samples collected twice from mothers during pregnancy and up to seven times from children at 1, 2, 3, 4, 5, 8, and 12 years. At age 12 years, we assessed fat and lean mass of the whole body and android and gynoid subregions, and visceral fat area with dual x-ray absorptiometry, and calculated android to gynoid %fat ratio and age- and sex-standardized fat and lean mass index z-scores. Using a multiple informant model, we estimated covariate-adjusted associations between urinary phthalate biomarker concentrations at each time period and outcomes at age 12 years. We assessed effect measure modification by child sex using stratified models.

RESULTS

Generally, urinary mono-benzyl phthalate (MBzP) concentrations were modestly associated with lower fat and lean mass. Each 10-fold increase in urinary MBzP concentrations during gestation and at ages 5 and 8 years was associated with a -0.34 (95%CI: -0.72, 0.05), -0.44 (95% CI: -0.83, -0.05), and -0.35 (95% CI: -0.71, 0.00) z-score difference in lean body mass index, respectively. Urinary monoethyl phthalate, mono-(3-carboxypropyl) phthalate, and summed di(2-ethylhexyl) phthalate metabolites were associated with greater lean mass at some exposure periods. Slightly weaker but similar patterns of association were found with other body composition measures; associations did not differ by child sex.

CONCLUSION

While most associations were weak, exposure to certain phthalates during gestation and childhood may be associated with adolescent body composition, particularly lean mass.