Body-composition reference data for simple and reference techniques and a 4-component model: a new UK reference child

Preservation of fat mass at the expense of lean mass in children with end-stage chronic liver disease

BACKGROUND

Sarcopenia predicts morbidity and mortality in end-stage chronic liver disease (ESCLD). Here, we describe changes in body composition in children with ESCLD before and after liver transplantation (LT).

METHODS

Retrospective analysis of whole body DXA scans performed before and after LT over 4 years. Appendicular and whole-body fat mass and lean mass were expressed as fat mass (FMI) and lean mass (LMI) index z-scores. Sarcopenia was defined as leg LMI z-score <-1.96.

RESULTS

Eighty-three DXA scans of children before or after LT were studied. Sarcopenia had a positive correlation with weight (0.8, p < .01), height (0.48, p < .05), and BMI z-score (0.77, p < .01), as well as arm, trunk, and total mean mass indices. It correlated negatively with indices of hypersplenism: PLTs (-0.57, p < .01), Neu (-0.50, p < .05), WCC (-0.44, p < .05), and days to discharge (-0.46, p < .05). At baseline: 13/25 (52%) children were sarcopenic and stayed in the hospital after LT for longer. Eight were stunted with a higher WCC and Ne/Ly ratio. All had normal FM indices. One year after LT, 12/26 children remained sarcopenic. Seven were stunted. Two years after LT, 5/15 were sarcopenic, and 5 were stunted. Three years after LT, 1/10 was sarcopenic, and 2 were stunted. By 4 years after LT, 1/7 was sarcopenic, and the same one was stunted. FM indices remained normal.

CONCLUSIONS

Sarcopenic patients stayed longer in the hospital after LT. Lean mass indices were mostly within the normal range by 4 years after LT. 32% of children were stunted, and markers of inflammation were correlated with stunting. Fat mass was preserved at the cost of lean mass.

Timing, velocity, and magnitude of pubertal changes in body composition: a longitudinal study

BACKGROUND

Pubertal changes in body composition significantly influence future health, with links to various diseases. This study aimed to evaluate the weight changes, fat-free mass (FFM), and body fat mass (BFM) during pubertal growth in Korean children and adolescents.

METHODS

We utilized mixed longitudinal data, employing bioelectrical impedance analysis for 4641 height measurements (2204 boys, 2437 girls) from 361 individuals (170 boys, 191 girls) aged 7-18 years. Utilizing the Superimposition by Translation and Rotation (SITAR) model, a shape-invariant growth curve model, reference curves for height, weight, and body composition change velocities were estimated.

RESULTS

Korean boys experience peak weight velocity (PWV) at an average age of 12.41 years, with a rate of 8.19 kg/year, peak fat-free mass velocity (PFFV) at 12.70 years (7.60 kg/year), and peak body fat mass velocity (PBFV) at 9.69 years (2.67 kg/year). Korean girls show PWV at 11.28 years (6.33 kg/year), PFFV at 11.13 years (4.86 kg/year), and PBFV at 12.33 years (2.72 kg/year). Positive correlations exist among the ages of peak height velocity, PWV, PFFV, and PBFV.

CONCLUSIONS

This research represents the groundbreaking application of the SITAR model in analyzing changes in body composition during pubertal growth in Korean children and adolescents.

IMPACT

This study utilized the SITAR model to analyze longitudinal changes in the body composition of the general pediatric population in Korea across pre- and post-pubertal stages, addressing overlooked aspects in cross-sectional studies. Examining growth parameters, including size (mean mass), tempo (timing), and velocity (compression and expansion) for each body component, revealed positive correlations among ages at peak velocities for various body composition parameters. This study can be employed for further investigations that compare the tempo, size, and velocity of various body composition parameters in pediatric disease cohorts and the general population.

Measuring body composition in pediatric patients with complex diagnoses: Acceptability, practicality, and validation of different techniques

BACKGROUND

Body composition could help identify malnutrition in pediatric patients, but there is uncertainty over which techniques are most suitable and prevailing opinion that measurements are difficult to obtain in practice. This study examined the acceptability, practicality, reliability, and validity of different anthropometric and body composition measurements in patients with complex diagnoses in a tertiary pediatric hospital.

METHODS

A total of 152 children aged 5-18 years had weight, height, body mass index (BMI), mid-upper arm circumference (MUAC), 4-site skinfold thicknesses (SFT), bioelectrical impedance analysis (BIA), and dual-energy x-ray absorptiometry (DXA) assessed on admission and discharge. Acceptability was assessed in a continuous scale, practicality with number/percentage of successful measurements, reliability with intraclass correlation coefficients and coefficients of repeatability, and validity between "simpler" techniques and DXA with Bland-Altman analysis of agreement and Cohen kappa.

RESULTS

Techniques were overall acceptable. Measurements were successful in >50%, with patient refusal uncommon. Coefficients of repeatability were good (0.3 cm MUAC and height, 0.2 kg weight, and 1.0 mm SFTs). All techniques significantly overestimated DXA fat mass, but BMI and triceps SFT better identified abnormal fat mass (κ = 0.46 and 0.49). BIA fat-free mass was not significantly different from DXA, with substantial agreement between techniques (κ = 0.65).

CONCLUSION

Body composition by a range of techniques is acceptable, practical, and reliable in a diverse group of children with complex diagnoses. BIA seems a good alternative to DXA for assessing fat-free mass, triceps SFT, and BMI for fat mass but should be used with care as it could overestimate total fat mass in individuals.

Associations of early childhood body mass index trajectories with body composition and cardiometabolic markers at age 10 years: the Ethiopian infant anthropometry and body composition (iABC) birth cohort study

BACKGROUND

Variability in body mass index (BMI) (kg/m2) trajectories is associated with body composition and cardiometabolic markers in early childhood, but it is unknown how these associations track to later childhood.

OBJECTIVES

We aimed to assess associations of BMI trajectories from 0 to 5 y with body composition and cardiometabolic markers at 10 y.

METHODS

In the Ethiopian infant anthropometry and body composition (iABC) birth cohort, we previously identified 4 distinct BMI trajectories from 0 to 5 y: stable low BMI (19.2%), normal BMI (48.8%), rapid growth to high BMI (17.9%), and slow growth to high BMI (14.1%). At 10 y, we obtained data from 320 children on anthropometry, body composition, abdominal subcutaneous and visceral fat, and cardiometabolic markers. Associations of BMI trajectories and 10-y outcomes were analyzed using multiple linear regression.

RESULTS

Compared with children with the normal BMI trajectory, those with rapid growth to high BMI had 1.7 cm (95% CI: 0.1, 3.3) larger waist circumference and those with slow growth to high had 0.63 kg/m2 (95% CI: 0.09, 1.17) greater fat mass index and 0.19 cm (95% CI: 0.02, 0.37) greater abdominal subcutaneous fat, whereas those with stable low BMI had -0.28 kg/m2 (95% CI: -0.59, 0.03) lower fat-free mass at 10 y. Although the confidence bands were wide and included the null value, children with rapid growth to high BMI trajectory had 48.6% (95% CI: -1.4, 123.8) higher C-peptide concentration and those with slow growth to high BMI had 29.8% (95% CI: -0.8, 69.8) higher insulin and 30.3% (95% CI: -1.1, 71.6) higher homeostasis model assessment of insulin resistance, whereas those with rapid growth to high BMI had -0.23 mmol/L (95% CI: -0.47, 0.02) lower total cholesterol concentration. The trajectories were not associated with abdominal visceral fat, blood pressure, glucose, and other lipids at 10 y.

CONCLUSIONS

Children with rapid and slow growth to high BMI trajectories before 5 y tend to show higher measures of adiposity and higher concentrations of markers related to glucose metabolism at 10 y.

CLINICAL TRIAL REGISTRY

ISRCTN46718296 (https://www.isrctn.com/ISRCTN46718296).

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 composition and motor function in children born large for gestational age at term

BACKGROUND

This cross-sectional study compared body composition and motor function between children who were born large for gestational age (LGA) and those born appropriate for gestational age (AGA) and to investigate the association between gait quality and other variables.

METHODS

Body composition was determined using a bioelectrical impedance analyzer. Motor functions were assessed using one-leg standing time, timed up-and-go test, five times sit-to-stand test, and three-dimensional gait analysis. We compared the results between two groups. We performed multiple regression analysis to evaluate the association between gait deviation index and variables of LGA, fat mass index, and motor functions (adjusted for age and sex).

RESULTS

Children aged 6-12 years who were born LGA at term (n = 23) and those who were born AGA at term (n = 147) were enrolled. The LGA group had a higher fat mass index (2.9 vs. 2.2, p = 0.006) and lower gait deviation index (91.4 vs. 95.4, p = 0.011) than the AGA group. On multiple regression analysis, gait deviation index was associated with being LGA and fat mass index.

CONCLUSIONS

In school-aged children who were born LGA, monitoring increased fat mass index and decreased gait deviation index could lessen the risk of metabolic syndrome and reduced gait function.

IMPACT

Children aged 6-12 years who were born large for gestational age (LGA) at term showed a higher fat mass index and lower gait deviation index than those who were born appropriate for gestational age at term. No significant differences in balance function or muscle strength were observed between groups. On multiple regression analysis, gait deviation index was associated with being LGA at birth and fat mass index. In school-aged children who were born LGA, monitoring increased fat mass index and decreased gait deviation index could lessen the risk of metabolic syndrome and reduced gait function.

Waist-circumference-to-height-ratio had better longitudinal agreement with DEXA-measured fat mass than BMI in 7237 children

BACKGROUND

The absolute agreement of surrogate measures of adiposity with dual-energy X-ray absorptiometry (DEXA)-measured body composition was examined.

METHODS

Over a 15-year follow-up, 7237 (3667 females) nine-year-old children from the Avon Longitudinal Study of Parents and Children (ALSPAC) UK birth cohort were included. Total fat mass (FM) and trunk FM were serially measured with DEXA at ages 9, 11, 15, 17, and 24 years. BMI and waist circumference-to-height ratio (WHtR) were computed. Pearson's correlations, intraclass correlations (ICC), and area under curve (AUC) analyses were conducted.

RESULTS

Over 15 years, BMI, total FM, and trunk FM, increased but WHtR was relatively stable. WHtR provided a better longitudinal absolute agreement [males ICC 0.84 (95% CI 0.84-0.85); females 0.81 (0.80-0.82)] than BMI [(males (0.65 (0.64-0.66); females 0.72 (0.71-0.73)] with total FM as well as trunk FM from ages 9-24 years. WHtR cut-point for predicting excess total FM (75th-95th percentile) was 0.50-0.53 in males [AUC 0.86-0.94, sensitivity 0.51-0.79 and specificity 0.93-0.95]. WHtR cut-point for predicting excess total FM (75th-95th percentile) was 0.52-0.54 in females [AUC 0.83-0.95, sensitivity 0.38-0.68 and specificity 0.92-0.95]. Results were similar with trunk FM.

CONCLUSION

WHtR is an inexpensive alternative to BMI for predicting FM in pediatrics.

IMPACT

Waist circumference-to-height ratio (WHtR) is a better adiposity surrogate measure than body mass index (BMI) in predicting fat mass and discriminating lean mass from childhood through young adulthood. BMI has been used as an inexpensive surrogate measure of adiposity in children for several decades. However, emerging findings suggest that BMI fails to discriminate between fat mass adiposity and lean mass. This is the first-ever longitudinal study in over 7000 children followed up for 15 years that identified WHtR as an inexpensive accurate measure that discriminates fat mass from lean mass that could replace BMI measure of obesity in pediatrics.

Body Composition Evaluation and Clinical Markers of Cardiometabolic Risk in Patients with Phenylketonuria

Cardiovascular diseases are the main cause of mortality worldwide. Patients with phenylketonuria (PKU) may be at increased cardiovascular risk. This review provides an overview of clinical and metabolic cardiovascular risk factors, explores the connections between body composition (including fat mass and ectopic fat) and cardiovascular risk, and examines various methods for evaluating body composition. It particularly focuses on nutritional ultrasound, given its emerging availability and practical utility in clinical settings. Possible causes of increased cardiometabolic risk in PKU are also explored, including an increased intake of carbohydrates, chronic exposure to amino acids, and characteristics of microbiota. It is important to evaluate cardiovascular risk factors and body composition in patients with PKU. We suggest systematic monitoring of body composition to develop nutritional management and hydration strategies to optimize performance within the limits of nutritional therapy.

The relative contributions of soft tissue mass components as risk or protective factors of non-alcoholic fatty liver disease in children

BACKGROUND/OBJECTIVE

Several body components are known to be associated with non-alcoholic fatty liver disease (NAFLD) in children. However, the relative contributions of soft tissue mass components as risk or protective factors of NAFLD are largely unknown because measurements of these components are often highly correlated. Therefore, we aimed to estimate levels of association between soft tissue mass components and NAFLD.

SUBJECTS/METHODS

We collected the medical records of 555 Chinese children (aged 3-18 years). Five mutually exclusive and exhaustive components of soft tissue mass were measured using dual energy X-ray absorptiometry. NAFLD was diagnosed with abdominal B-ultrasound scan. We fit Dirichlet regression and multivariate linear regression models wherein age and NAFLD were used as predictors of the proportional measurements of soft tissue mass components.

RESULTS

The proportion of android fat was significantly higher in children with NAFLD than in those without NAFLD (ratio of proportions ranged from 1.18 to 1.30), whereas proportions of trunk lean and limb lean were significantly lower (ratio of proportions ranged from 0.87 to 0.92 for trunk lean and from 0.82 to 0.91 for limb lean). The proportion of gynoid fat was slightly higher in boys with NAFLD than in those without NAFLD (ratio = 1.05), but this proportion was not significantly higher in girls. The association between the proportion of android fat and NAFLD appeared to be somewhat greater than the associations between proportions of trunk lean or limb lean components and NAFLD.

CONCLUSION

Our findings suggest that lowering fat mass and increasing lean mass can both be used to combat NAFLD in children and that more studies are needed to determine the association between gynoid fat and NAFLD.

The Associations of Breastfeeding Status at 6 Months with Anthropometry, Body Composition, and Cardiometabolic Markers at 5 Years in the Ethiopian Infant Anthropometry and Body Composition Birth Cohort

(1) Background: Breastfeeding (BF) has been shown to lower the risk of overweight and cardiometabolic disease later in life. However, evidence from low-income settings remains sparse. We examined the associations of BF status at 6 months with anthropometry, body composition (BC), and cardiometabolic markers at 5 years in Ethiopian children. (2) Methods: Mother-child pairs from the iABC birth cohort were categorised into four BF groups at 6 months: 1. "Exclusive", 2. "Almost exclusive", 3. "Predominantly" and 4. "Partial or none". The associations of BF status with anthropometry, BC, and cardiometabolic markers at 5 years were examined using multiple linear regression analyses in three adjustment models. (3) Results: A total of 306 mother-child pairs were included. Compared with "Exclusive", the nonexclusive BF practices were associated with a lower BMI, blood pressure, and HDL-cholesterol at 5 years. Compared with "Exclusive", "Predominantly" and "Almost exclusive" had shorter stature of -1.7 cm (-3.3, -0.2) and -1.2 cm (-2.9, 0.5) and a lower fat-free mass index of -0.36 kg/m2 (-0.71, -0.005) and -0.38 kg/m2 (-0.76, 0.007), respectively, but a similar fat mass index. Compared with "Exclusive", "Predominantly" had higher insulin of 53% (2.01, 130.49), "Almost exclusive" had lower total and LDL-cholesterol, and "Partial or none" had a lower fat mass index. (5) Conclusions: Our data suggest that children exclusively breastfed at 6 months of age are overall larger at 5 years, with greater stature, higher fat-free mass but similar fat mass, higher HDL-cholesterol and blood pressure, and lower insulin concentrations compared with predominantly breastfed children. Long-term studies of the associations between BF and metabolic health are needed to inform policies.

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.

Cross-sectional assessment of body composition and detection of malnutrition risk in participants with low body mass index and eating disorders using 3D optical surface scans

BACKGROUND

New recommendations for the assessment of malnutrition and sarcopenia include body composition, specifically reduced muscle mass. Three-dimensional optical imaging (3DO) is a validated, accessible, and affordable alternative to dual X-ray absorptiometry (DXA).

OBJECTIVE

Identify strengths and weaknesses of 3DO for identification of malnutrition in participants with low body mass index (BMI) and eating disorders.

DESIGN

Participants were enrolled in the cross-sectional Shape Up! Adults and Kids studies of body shape, metabolic risk, and functional assessment and had BMI of <20 kg/m2 in adults or <85% of median BMI (mBMI) in children and adolescents. A subset was referred for eating disorders evaluation. Anthropometrics, scans, strength testing, and questionnaires were completed in clinical research centers. Lin's Concordance Correlation Coefficient (CCC) assessed agreement between 3DO and DXA; multivariate linear regression analysis examined associations between weight history and body composition.

RESULTS

Among 95 participants, mean ± SD BMI was 18.3 ± 1.4 kg/m2 in adult women (N = 56), 19.0 ± 0.6 in men (N = 14), and 84.2% ± 4.1% mBMI in children (N = 25). Concordance was excellent for fat-free mass (FFM, CCC = 0.97) and strong for appendicular lean mass (ALM, CCC = 0.86) and fat mass (FM, CCC = 0.87). By DXA, 80% of adults met the low FFM index criterion for malnutrition, and 44% met low ALM for sarcopenia; 52% of children and adolescents were <-2 z-score for FM. 3DO identified 95% of these cases. In the subset, greater weight loss predicted lower FFM, FM, and ALM by both methods; a greater percentage of weight regained predicted a higher percentage of body fat.

CONCLUSIONS

3DO can accurately estimate body composition in participants with low BMI and identify criteria for malnutrition and sarcopenia. In a subset, 3DO detected changes in body composition expected with weight loss and regain secondary to eating disorders. These findings support the utility of 3DO for body composition assessment in patients with low BMI, including those with eating disorders. This trial was registered at clinicaltrials.gov as NCT03637855.

Magnetic Resonance Imaging Can Be Used to Assess Sarcopenia in Children with Newly Diagnosed Crohn's Disease

BACKGROUND

This study aimed to determine the proportion of patients with sarcopenia diagnosed by MRI and compare these results to bioelectrical impedance analysis (BIA).

METHODS

Children with newly diagnosed Crohn's disease (CD) who had MRI enterography (MRE) and BIA and had at least 12 months of follow-up were included. Total psoas muscle area (TPMA) and total paravertebral muscle (TPVM) were measured and compared to subjects' lean mass and the lean mass body index (LMBI) was assessed by BIA.

RESULTS

30 newly diagnosed children with CD were included (mean age 14.2 years, 53% male). Sarcopenia was found in 13 (43%) children; mean TPMA was 15.2 (1.1 SD) cm2 and TPVM 30.95 (1.7 SD) cm2. A highly positive correlation was shown for lean mass assessed by BIA and TPMA (0.706, p < 0.001) and TPVM (0.75, p < 0.001). Sarcopenia was more prevalent in boys (77% vs. 24%, p = 0.004), patients with the perianal disease (69% vs. 29%, p = 0.03), and children with sarcopenia were likely to receive anti-TNF (77% vs. 41%, p = 0.05). During the follow-up period, 16 (53%) children experienced a relapse. TPMA (HR 0.99, p = 0.018) and TPVM (HR 0.99, p = 0.031) values were statistically significant risk factors for relapse.

CONCLUSION

A high proportion of patients with CD have sarcopenia at the time of the diagnosis. There is a good correlation between muscle mass assessed by MRI and BIA. Because MRI is performed in a great proportion of newly diagnosed CD patients it can also be used to assess the presence of sarcopenia.

Association Between Adipokine Profile, Systemic Inflammation, Muscle and Protein Energy Wasting in Children With Chronic Kidney Disease

OBJECTIVES

This cross-sectional study explores the association of adipokines and interleukin-6 (IL-6) with muscle and protein energy wasting (PEW) in children with chronic kidney disease (CKD).

METHODS

We measured serum adiponectin, leptin, resistin and IL-6 in 53 patients with CKD stage 3-5. Lean tissue (LTI) and fat tissue index (FTI) were estimated by bioimpedance analysis spectroscopy. PEW was defined as muscle wasting [LTI adjusted to height age (LTI HA) z-score < -1.65 SD) and at least 2 of the following: reduced body mass [body mass index adjusted to height age (BMI HA) z-score < -1.65 SD), poor growth [height z-score < -1.88 SD], questionnaire-based decreased appetite, and serum albumin ≤3.8 g/dL.

RESULTS

PEW, observed in 8 (15.1%) patients, was more prevalent in CKD stage 5 (P = .010). Among the adipokines, adiponectin, and resistin levels were significantly higher in CKD stage 5 (P < .001, P = .005). Adiponectin was correlated to LTI HA z-score (Rs = -0.417, P = .002), leptin to FTI z-score (Rs = 0.620, P < .001), while no correlation was observed between resistin and body composition parameters. Resistin was the only adipokine correlated to IL-6 (Rs = 0.513, P < .001). After adjustment for CKD stage and patient age, PEW was associated with adiponectin and IL-6 rise by 1 μg/mL and 10 pg/mL respectively (odds ratio (OR) 1.240, 95% confidence interval (CI) 1.040, 1.478 and OR 1.405, 95% CI 1.075-1.836) but not with leptin, while resistin association with PEW lost its significance.

CONCLUSIONS

In pediatric CKD, adiponectin is associated with muscle wasting, leptin with adiposity and resistin with systemic inflammation. Adiponectin and cytokine IL-6 may serve as PEW biomarkers.

Assessment of body composition in pediatric intestinal failure: A comparison study

BACKGROUND

The objective of the study was to compare bioelectrical impedance analysis (BIA) and skinfolds with dual energy x-ray absorptiometry (DXA) in the assessment of body composition of children with intestinal failure. DXA is the reference method for body composition assessment in clinical settings.

METHODS

Children aged 1-18 years with intestinal failure whohave DXA as part of routine clinical monitoring were eligible. BIA measured total body water on the same day as DXA. Skinfold measurements were taken at four sites: triceps, biceps, subscapular, and suprailiac. Percentage of fat mass (%FM) and fat-free mass (%FFM) were derived from resistance and reactance measured by BIA by using age-specific equations. Percentage of FM was calculated from skinfold measures by using age-specific equations. Data on patient characteristics, intestinal failure-related factors, and feeding method were collected. Paired t test examined differences in %FM and %FFM and Bland-Altman analysis determined the agreement between BIA, skinfolds, and DXA. Marginal linear model assessed the effect of age, sex, and feeding method on the difference in body composition obtained between DXA and BIA and between DXA and skinfolds.

RESULTS

Sixty-eight children with intestinal failure, mean age 8.9 ± 4.2 years, were studied. There was no difference between %FFM and %FM obtained by DXA and BIA (P = 0.26), with a mean bias (95% CI) of -0.69 (-1.9 to 0.5) for %FFM. Sex and age were individually and jointly associated with the bias observed between DXA and BIA (P < 0.05). Skinfold and DXA measurements were significantly different (P < 0.05).

CONCLUSIONS

BIA is an acceptable clinical tool for assessing body composition in pediatric intestinal failure.

Body composition and body mass index measures from 8 to 18 years old in children with cystic fibrosis

BACKGROUND

Historically, body mass index (BMI) >50th percentile has represented optimal nutritional status in children with cystic fibrosis (CF) due to its positive association with lung function. Body composition parameters including fat-free mass index (FFMI) have been suggested as a more physiological nutrition benchmark.

AIMS

(1) describe changes in body composition with age and gender; (2) assess the correlation between measures of nutritional status (FFMI-z, FMI-z, BMI-z) and lung function (forced expiratory volume in one second predicted; FEV1pp).

METHODS

This retrospective, mixed cross-sectional and serial measures study consisted of children with CF (8 to 18 years) attending Sydney Children's Hospital (2007-2020). FFMI and fat mass index (FMI) were taken from biennial dual energy x-ray absorptiometry (DXA) scans. Z-scores were derived using Well's reference population [1]. Repeated measures correlation analyses assessed correlations between FFMI-z, FMI-z, and BMI-z with FEV1pp.

RESULTS

339 DXA reports were analysed from 137 patients. There were slight downwards trends in BMI-z and FMI-z, and an upwards trend in FFMI-z with increasing age and across both genders. Females had higher FMI-z and FFMI-z than males from 12.5 years. There was a weak, positive correlation between FEV1pp and BMI-z (r = 0.14, p = 0.04), and FFMI-z (r = 0.25, p<0.001). FMI-z had no correlation with FEV1pp (r=-0.06, p = 0.41).

CONCLUSION

Deficits in FFMI exist despite increasing trends with age. FFMI-z and BMI-z had a weak, positive correlation with FEV1pp. In contemporary cohorts, nutritional status (reflected by surrogate markers such as FFMI and BMI) may be less influential upon lung function than in previous decades. [1]: Wells, J.C., et al. Body-composition reference data for simple and reference techniques and a 4-component model: a new UK reference child. Am. J. Clin. Nutr.96, 1316-1326 (2012).

Validity of the neck circumference for the diagnosis of obesity in school children living at high altitude

Introduction

Background: body mass index (BMI) is commonly used to diagnose overweight and obesity, and waist circumference (WC) is used to estimate visceral fat. The measurement of WC is demanding, therefore, different studies proposed the use of neck perimeter. Objective: exploring diagnostic validity of neck perimeter to diagnose overweight and obesity in 10-12 years old children in La Paz (Bolivia). Methods: this is a cross-sectional study with a random sample of school children in El Alto (Bolivia). Weight, height, abdominal circumference and neck perimeter were measured, classifying the nutritional status with BMI-z according to the cut-off point of the World Health Organization (WHO) classification. The sample size was calculated for 95 % confidence level, an alpha level of 0.05 and 80 % power for diagnosis test design. To evaluate neck perimeter validity for diagnosing obesity, sensibility, specificity and positive and negative ratio likelihood were calculated using BMI gold standard according to age and sex. Results: a number of 371 school children between 10-12 years old were included and 34 % of them presented malnutrition by excess. Sensibility and specificity of the neck perimeter to diagnose overweight and obesity were 87.5-100 % and 75.7-86.3 %, respectively. Conclusion: neck perimeter in 10-12-year-old school children is a valid indicator for carrying out obesity diagnosis.

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.

Centile reference chart for resting metabolic rate through the life course

OBJECTIVE

Reference centile charts are widely used for the assessment of growth and have progressed from describing height and weight to include body composition variables such as fat and lean mass. Here, we present centile charts for an index of resting energy expenditure (REE) or metabolic rate, adjusted for lean mass versus age, including both children and adults across the life course.

DESIGN, PARTICIPANTS AND INTERVENTION

Measurements of REE by indirect calorimetry and body composition using dual-energy X-ray absorptiometry were made in 411 healthy children and adults (age range 6-64 years) and serially in a patient with resistance to thyroid hormone α (RTHα) between age 15 and 21 years during thyroxine therapy.

SETTING

NIHR Cambridge Clinical Research Facility, UK.

RESULTS

The centile chart indicates substantial variability, with the REE index ranging between 0.41 and 0.59 units at age 6 years, and 0.28 and 0.40 units at age 25 years (2nd and 98th centile, respectively). The 50th centile of the index ranged from 0.49 units (age 6 years) to 0.34 units (age 25 years). Over 6 years, the REE index of the patient with RTHα varied from 0.35 units (25th centile) to 0.28 units (<2nd centile), depending on changes in lean mass and adherence to treatment.

CONCLUSION

We have developed a reference centile chart for an index of resting metabolic rate in childhood and adults, and shown its clinical utility in assessing response to therapy of an endocrine disorder during a patient's transition from childhood to adult.

[Adaptation in Spanish and validation in Mexico of the Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP]

BACKGROUND

pediatric malnutrition is one of the main causes of complications in hospitalized children. Nutritional screening at admission is essential. The Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP) is a simple, reproducible and easy-to-interpret tool, but it is not validated in Mexico. The objective of the study was to validate and adapt the STAMP nutritional screening tool to the Mexican population.

METHODS

the validation was carried out in two phases: firstly, the translation and cultural adaptation was carried out; and secondly, a cross-sectional study was performed comparing the STAMP tool with a complete nutritional assessment (CNA). A pediatrician specialized in nutrition performed the CNA with the evaluation of anthropometric, clinical and dietary parameters; later, two nutritionists carried out the same evaluation with the STAMP tool. Finally, the patients were graded as low risk and moderate or severe malnutrition risk.

RESULTS

of the 300 patients included in the study, 160 were boys (53.3 %) and 140 were girls (46.7 %), with a mean age of 9.44 ± 5.73 years. The assessments made by with the STAMP tool had a 100 % concordance. Compared with CNA, a kappa index of 0.480 (p < 0.01) was obtained. The STAMP test showed a sensitivity of 92 %, a specificity of 75 %, positive predictive value (PPV) of 45 %, negative predictive value (NPV) of 97 %, RVN of 3,68, and RVN of 0,10.

CONCLUSIONS

the STAMP screening tool has the necessary elements to objectively assess the risk of malnutrition in Mexican children and is a highly sensitive and specific test. test.

Recreational screen time trajectories during early childhood and imaging-measured body composition at age 7 in the Odense child cohort

BACKGROUND

Children spend increasing amounts of time on recreational screen media, which may lead to an obesogenic environment.

OBJECTIVES

We investigated the association of trajectories of screen time across ages 3, 5 and 7 years with body composition at age 7 in the Odense Child Cohort.

METHODS

Data were collected in the Municipality of Odense, Denmark, between 2010 and 2019. Group-based trajectory modelling was applied to group participants into four trajectories of prospective parent-reported screen time. Body composition was assessed using dual-energy x-ray absorptiometry with calculated fat-mass index (FMI) as the primary outcome. Primary models were linear multivariable regression models adjusted for participants' sex, age, birthweight, maternal origin, maternal education, maternal body-mass-index, and maternal age. Further models were adjusted for additional possible confounders. Selection bias was addressed by inverse probability weighting.

RESULTS

In total, 803 children (48.2% female) were included in the primary analysis. Participants with screen time at all time points were assigned to four trajectory groups [constant low screen time (12.7%), low increase (36.3%), high increase between ages 3 and 5 (33.5%) and high increase in screen time (17.5%)]. Sample characteristics differed across missing data status and trajectories. Mean FMI (kg/m² ) and standard deviation (SD) were 3.7 (SD 1.3) and 3.9 (SD 1.6) for the constant low versus high screen time, respectively. No differences in FMI were found between screen time trajectory groups at age 7 (adjusted mean difference 0.1 kg/m² , 95% confidence interval -0.3, 0.5 for constant low versus high screen time). No consistent associations between screen time groups and secondary body composition outcomes were found.

CONCLUSIONS

Results from this study do not suggest that recreational screen time from age 3 to 7 years is associated with adiposity or other measures of body composition.

Physical activity and liver disease affect the fat-free mass in adolescents with cystic fibrosis

Cystic fibrosis (CF) is predominantly a lung disease but is also characterised by impaired skeletal muscularity and a reduction in fat-free mass. We aimed to test the hypothesis that clinical and anthropometric parameters would determine fat-free mass impairment in adolescents with CF. We measured the fat-free mass index (FFMI) using bioelectrical impedance, the lung function using spirometry, the number of shuttles as a measure of exercise tolerance and the reported physical activity in children and young people with CF in a tertiary centre at King's College Hospital, London, UK. CF-related liver disease was diagnosed by abnormal liver enzymes and/or ultrasonography. We studied 28 children and young people (11 male) with a median (interquartile range (IQR)) age of 15 (13-17) years. They had a median (IQR) FFMI of 13.5 (11.6-15.1) kg/m². The FFMI significantly correlated with age (rho = 0.568, p = 0.002), number of shuttles (rho = 0.691, p < 0.001) and reported hours of activity per day (rho = 0.426, p = 0.024). The median (IQR) FFMI was significantly higher in male [15.1 (13.1-18.6) kg/m²] compared to female participants [12.7 (11.6-14.1) kg/m², p = 0.008]. The median (IQR) FFMI was significantly lower in the 10 (36%) participants with liver disease [11.9 (11.5-13.4) kg/m²] compared to the FFMI in the remaining 18 participants without liver disease [14.4 (12.5-15.9) kg/m², p = 0.027].

CONCLUSION

Fat-free mass increases with increasing age and growth in adolescents with CF. Physical activity exerts a beneficial effect on fat-free mass, and CF-related liver disease negatively affects fat-free mass in adolescents with CF.

WHAT IS KNOWN

• Health behaviours in adolescence influence lifelong health in cystic fibrosis (CF). • A normal body mass index in CF might fail to reveal a low fat-free mass (FFM), and quality of life in CF is strongly associated with a reduced FFM.

WHAT IS NEW

• FFM increases with increasing age and growth in adolescents with CF. • Physical activity exerts a beneficial effect, and liver disease negatively affects FFM in adolescents with CF.

Influence of Vitamin D Supplementation on Growth, Body Composition, and Pubertal Development Among School-aged Children in an Area With a High Prevalence of Vitamin D Deficiency: A Randomized Clinical Trial

Importance

Vitamin D deficiency (defined as 25-hydroxyvitamin D [25(OH)D] <20 ng/mL) is prevalent among children living in temperate climates and has been reported to associate independently with stunting, obesity, and early activation of the hypothalamic-pituitary-gonadal axis. Phase 3 randomized clinical trials to investigate the influence of long-term vitamin D replacement on growth, body composition, and pubertal development of school-aged children with vitamin D deficiency are lacking.

Objective

To determine whether weekly oral vitamin D supplementation influences linear growth, body composition, or pubertal development in school-aged children living in a setting where vitamin D deficiency is highly prevalent.

Design, Setting, and Participants

This secondary analysis of a double-blind, placebo-controlled randomized clinical trial was conducted from June 2016 to June 2019 at 18 grade schools in Ulaanbaatar, Mongolia. School-aged children (6 to 13 years at baseline) attending participating schools were included. Exclusion criteria included a positive QuantiFERON-TB Gold in-tube assay result, conditions or medications associated with altered vitamin D metabolism, use of vitamin D supplements, signs of rickets, or intention to move from Ulaanbaatar within 4 years. Of 11 475 children invited to participate in the study, 9814 underwent QFT testing, and 8851 with negative results were included in the study. All but 1 participant in the placebo group completed follow-up and were included in the present analysis. Data were analyzed from November 2021 to February 2022.

Interventions

Weekly oral doses of vitamin D3, 14 000 IU, (n = 4418), or placebo (n = 4433) for 3 years.

Main Outcomes and Measures

Mean z scores for height for age, body mass index for age, and waist-to-height ratio; mean percentage body fat, fat mass, and fat-free mass; and mean Tanner scores for pubertal development.

Results

Of 8851 participants, 4366 (49.3%) were female, and 8165 (92.2%) were of Khalkh ethnicity; the mean (SD) age was 9.4 (1.6) years. A total of 8453 participants (95.5%) were vitamin D deficient at baseline, and mean end-of-study 25(OH)D concentrations among participants randomized to vitamin D vs placebo were 31.0 vs 10.7 ng/mL (mean difference, 20.3; 95% CI; 19.9-20.6). However, vitamin D supplementation did not influence mean height for age, body mass index for age, waist-to-height ratio, percentage body fat, fat mass, fat-free mass, or Tanner scores, either overall or within subgroups defined by baseline 25(OH)D concentration less than 10 ng/mL vs 10 ng/mL or greater, estimated calcium intake less than 500 mg/d vs 500 mg/d or greater, or male vs female sex.

Conclusions and Relevance

In school-aged children in this study with low baseline vitamin D status, oral vitamin D3 supplementation at a dose of 14 000 IU per week for 3 years was effective in elevating 25(OH)D concentrations but did not influence growth, body composition, or pubertal development.

Trial Registration

ClinicalTrials.gov Identifier: NCT02276755.

Do maternal grandmothers influence breastfeeding duration and infant nutrition? Evidence from Merida, Mexico

OBJECTIVES

Breast-feeding is sensitive to somatic, hormonal, behavioral and psychological components of maternal capital. However, through grandmothering, older women may also influence breast-feeding by transferring informational resources to their daughters. We hypothesized that mothers with prolonged instrumental support from their own mother are more likely to have received advice and to have favorable attitudes/practices regarding breastfeeding, compared to those lacking such support, with implications for the grandchild's somatic capital.

METHODS

We recruited 90 mother-infant dyads (52 with grandmaternal support, 38 without) in Merida, Yucatan, Mexico. All children were first-borns, aged ~2 years. Anthropometry and body composition were assessed. Data on grandmother's breastfeeding advice and maternal breastfeeding duration were obtained by questionnaire. Maternal attitudes to breast-feeding were assessed using the Iowa Infant Feeding Attitude Scale.

RESULTS

Women with instrumental support were more likely to have received grandmaternal advice during pregnancy/infancy on exclusive breast-feeding duration (60% vs. 37%, p = 0.033) and the type of first complementary food (81% vs. 47%, p = 0.001). However, women with support had a less favorable attitude to breastfeeding than those without and breastfed their children for less time (median 5 vs. 10.5 months, p = 0.01). No group differences were found in children's length, weight, skinfolds or lean mass z-score.

DISCUSSION

Although grandmothers providing instrumental support provided advice regarding breastfeeding, their attitudes may reflect issues beyond nutritional health. Advice of maternal grandmothers did not promote extended breastfeeding, however the differences in breastfeeding attitudes were not associated with the children's nutritional status. Grandmothers should be included in public health interventions promoting breastfeeding.

Towards standardised and valid anthropometric indicators of nutritional status in middle childhood and adolescence

Recognition of the importance of nutrition during middle childhood (age 5-9 years) and adolescence (age 10-19 years) is increasing, particularly in the context of global food insecurity and rising overweight and obesity rates. Until now, policy makers have been slow to respond to rapidly changing patterns of malnutrition across these age groups. One barrier has been a scarcity of consistent and regular nutrition surveillance systems for these age groups. What should be measured, and how best to operationalise anthropometric indicators that have been the cornerstone of nutrition surveillance in younger children and in adults, has been the topic of ongoing debate. Even with consensus on the importance of a given anthropometric indicator, difficulties arise in interpreting trends over time and between countries owing to the use of different terminologies, reference data, and cutoff points. In this Viewpoint we highlight the need to revisit anthropometric indicators across middle childhood and adolescence, a process that will require WHO and UNICEF coordination, the engagement of national implementors and policy makers, and partnership with research communities and donors.

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.

Estimation of body fat in children with intellectual disability: development and cross-validation of a simple anthropometric method

OBJECTIVE

Population-level monitoring of body composition requires accurate, biologically-relevant, yet feasible methods for estimating percent body fat (%BF). The aim of this study was to develop and cross-validate an equation for %BF from Body Mass Index (BMI), age, and sex among children with intellectual disability (ID). This study further aimed to examine the performance of an existing BMI-based equation (Deurenberg equation) for %BF in children with ID.

METHOD

Participants were 107 children (63 boys; aged 6-15 years) with ID randomly allocated to development (n = 81) and cross-validation (n = 26) samples. Dual-Energy X-Ray Absorptiometry provided the criterion %BF.

RESULTS

The model including BMI, age, and sex (0 = male; 1 = female) had a significant goodness-of-fit in determining %BF (p < 0.001; R² = 0.69; SEE =5.68%). The equation was: %BF = - 15.416 + (1.394 × BMI) + (4.538 × age) - (0.262 × age²) + (5.489 × sex). The equation was cross-validated in the separate sample based on (i) strong correlation (r = 0.82; p < 0.001) and non-significant differences between actual and predicted %BF (28.6 ± 9.6% and 30.1 ± 7.1%, respectively); (ii) mean absolute error (MAE) = 4.4%; and (iii) reasonable %BF estimations in Bland-Altman plot (mean: 1.48%; 95% CI: 12.5, -9.6). The Deurenberg equation had a large %BF underestimation (mean: -7.1%; 95% CI: 5.3, -19.5), significant difference between actual and estimated %BF (28.6 ± 9.7% and 21.5 ± 7.0%, respectively; p < 0.001), and MAE = 8.1%.

CONCLUSIONS

The developed equation with BMI, sex, and age provides valid %BF estimates for facilitating population-level body fat screening among children with ID.

Bioelectrical Impedance Analysis (BIA)- Derived Phase Angle in Children and Adolescents: A Systematic Review

Phase angle (PhA), a directly-measured bioelectrical impedance analysis variable, is suggested to be a proxy of body cell mass as well as extracellular/intracellular water ratio, and is related to cellular integrity and functions. The aim of this systematic review was to evaluate PhA in healthy youths in relation to sex, age, weight status, physical fitness, and sports activities. A systematic literature search (preferred reporting items for systematic reviews and meta-analyses criteria) until January 2022 was performed using PubMed, Embase, Scopus, and Web of Science regarding studies on PhA in healthy children and adolescents 4-18 years of age. Quality was assessed according to the National Institute of Health. After removing duplicates and studies not fulfilling the inclusion criteria, 22 cross-sectional and 1 longitudinal were considered appropriate. As for quality, 14 articles were rated fair and 9 good. Ten studies found that PhA increases with age: the increase was more marked after puberty, whereas changes in younger subjects are by far less defined. A clear sex difference was found in adolescents, likely due to pubertal development. Limited evidence suggests that PhA increases in participants with very high BMI. Limited data were reported on physically active youths without convincing findings. Positive associations of PhA with physical fitness and fat-free mass were found in few studies. In conclusion, partial and limited evidence suggests that changes in PhA over the first 2 decades of life reflect modification in body composition and fat-free mass composition. Further studies are needed for confirming PhA as a relevant marker of nutritional status in youths.

Sarcopenia and Fat Mass in Children With Chronic Liver Disease and Its Impact on Liver Transplantation

In adults, weight loss and sarcopenia are prognostic indicators of poor outcomes for patients awaiting liver transplant (LT). We tested the hypothesis that sarcopenia in children awaiting LT was related to poor outcomes.

Methods

Children with end-stage chronic liver disease undergoing assessment for LT were recruited into an observational longitudinal study. Anthropometry and body composition (BC; whole-body dual-energy x-ray absorptiometry scan) were assessed before and, on average, 1 year after LT.

Results

Eleven children (6 females:5 males) were assessed (4.7 to 17.2 years; median, 9.9) at baseline. Nine children went on to have an LT. The aspartate aminotransferase-to-platelet ratio index had a significant positive correlation with trunk lean mass and trunk lean mass index (LMI) SD score (SDS). At baseline, 4 patients were sarcopenic with appendicular LMI SDS less than -1.96. All fat mass and fat mass index (FMI) SDSs were within the normal range (above -1.96). There was a strong negative correlation between FMI SDS and height SDS. After transplant, there was a significant reduction in trunk LMI from 1.20 to -0.51 (95% CI, 1.03-2.4; P < 0.01). Body mass index SDS had a negative correlation with days to discharge after transplant. The majority of patients discharged after 16 days were sarcopenic. One year after transplantation, all patients were alive with normal graft function regardless of BC before LT.

Conclusion

FMIs were normal regardless of LMIs and correlated negatively with height. BC was related to days to discharge after LT but not to outcomes a year after LT.

Body Composition Assessment in Mexican Children and Adolescents. Part 1: Comparisons between Skinfold-Thickness, Dual X-ray Absorptiometry, Air-Displacement Plethysmography, Deuterium Oxide Dilution, and Magnetic Resonance Imaging with the 4-C Model

The evaluation of body composition (BC) is relevant in the evaluation of children’s health-disease states. Different methods and devices are used to estimate BC. The availability of methods and the clinical condition of the patient usually defines the ideal approach to be used. In this cross-sectional study, we evaluate the accuracy of different methods to estimate BC in Mexican children and adolescents, using the 4-C model as the reference. In a sample of 288 Mexican children and adolescents, 4-C body composition assessment, skinfold-thickness (SF), dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), and deuterium dilution (D₂O) were performed, along with MRI in a subsample (52 participants). The analysis of validity was performed by correlation analysis, linear regression, and the Bland–Altman method. All methods analyzed showed strong correlations for FM with 4-C values and between each other; however, DXA and MRI overestimated FM, whereas skinfolds and ADP under-estimated FM. Conclusion: The clinical assessment of BC by means of SF, ADP, DXA, MRI and D₂O correlated well with the 4-C model and between them, providing evidence of their clinical validity and utility. The results from different methods are not interchangeable. Preference between methods may depend on their availability and the specific clinical setting.

Body composition data show that high BMI centiles overdiagnose obesity in children aged under 6 years

BACKGROUND

Most authorities define childhood overweight/obesity as a BMI exceeding the same high centile cutoff at all ages, but it seems unlikely that true obesity prevalence (excess body fat) is constant throughout childhood.

OBJECTIVES

We investigated how fat mass (FM) and lean mass (LM), adjusted for height, relate to BMI and each other across childhood, using a uniquely large database of body composition measures, estimated using gold standard methods.

METHODS

Cross-sectional and cohort data were collated from representative samples of healthy children aged 6 wk to 20 y and children attending obesity clinics aged 7-16 y. Body composition was measured by deuterium dilution up to age 4 y, and by either deuterium or the criterion 4-component model from 4 to 20 y. FM and LM were expressed, respectively, as fat mass index (FMI; FM/height2) and lean mass index (LMI; LM/height2).

RESULTS

There were 2367 measurements of weight, height, and body composition from 1953 individuals. Before age 6 y, the variability in FMI, LMI, and BMI was much less than after; FMI was low (mainly <8 kg/m2) and FMI and LMI were weakly negatively correlated. From mid-childhood, upper limits for both BMI and FMI rose, but FMI in children with BMI <91st centile still rarely exceeded 8. With increasing age, the correlation of FMI with LMI rose to 0.5-0.7, driven mainly by children with a high FMI also having a high LMI.

CONCLUSIONS

Raised fat levels are much less common at younger than older ages, and young children with a high BMI centile have lower FMI than older children with the same BMI centile. Current BMI centile cutoffs thus overdiagnose obesity in younger groups. More stringent cutoffs are required for children aged <6 y, matching the WHO recommendation for 0-5 y.

Causative Mechanisms of Childhood and Adolescent Obesity Leading to Adult Cardiometabolic Disease: A Literature Review

The past few decades have shown a worrisome increase in the prevalence of obesity and its related illnesses. This increasing burden has a noteworthy impact on overall worldwide mortality and morbidity, with significant economic implications as well. The same trend is apparent regarding pediatric obesity. This is a particularly concerning aspect when considering the well-established link between cardiovascular disease and obesity, and the fact that childhood obesity frequently leads to adult obesity. Moreover, most obese adults have a history of excess weight starting in childhood. In addition, given the cumulative character of both time and severity of exposure to obesity as a risk factor for associated diseases, the repercussions of obesity prevalence and related morbidity could be exponential in time. The purpose of this review is to outline key aspects regarding the current knowledge on childhood and adolescent obesity as a cardiometabolic risk factor, as well as the most common etiological pathways involved in the development of weight excess and associated cardiovascular and metabolic diseases.

Body Composition Characteristics of a Load-Capacity Model: Age-Dependent and Sex-Specific Percentiles in 5- to 17-Year-Old Children

INTRODUCTION

Body composition assessment is superior to the use of body mass index (BMI) to characterize the nutritional status in pediatric populations. For data interpretation, suitable reference data are needed; hence, we aimed to generate age-dependent and sex-specific body composition reference data in a larger population of children and adolescents in Germany.

METHODS

This is a cross-sectional study on a representative group of 15,392 5- to 17-year-old children and adolescents. Body composition was assessed by bioelectrical impedance analysis using a population-specific algorithm validated against air displacement plethysmography. Age- and sex-specific percentiles for BMI, fat mass index (FMI), fat-free mass index (FFMI), and a "load-capacity model" (characterized by the ratios of fat mass [FM]/ fatt-free mass [FFM] and FM/FFM2) were modeled using the LMS method.

RESULTS

BMI, FMI, FFMI, FM/FFM, and FM/FFM2 curves showed similar shapes between boys and girls with steady increases in BMI, FMI, and FFMI, while FM/FFM2-centiles decreased during early childhood and adolescence. Sex differences were observed in FMI and FM/FFM percentiles with increases in FMI up to age 9 years followed by a steady decrease in FM/FFM during and after puberty with a fast-growing FFMI up to age 17 in boys. The prevalence of low FFM relative to FM reached more than 60% in overweight children and adolescents.

CONCLUSION

These pediatric body composition reference data enable physicians and public health scientists to monitor body composition during growth and development and to interpret individual data. The data point out to an early risk of sarcopenia in overweight children and adolescents.

Reference values of fat mass index and fat-free mass index in healthy Spanish adolescents

Introduction

Introduction: body mass index (BMI) does not allow to discriminate the composition of the different body compartments. The aim of this study was to develop reference values for the fat mass index (FMI) and fat-free mass index (FFMI) in healthy adolescents using anthropometric techniques in order to provide reference standards for daily clinical practice. Methods: a cross-sectional study in 1,040 healthy Caucasian adolescents (470 boys and 570 girls) aged 10.1 to 14.9 years. Weight, height, and skinfold thickness were recorded, and BMI, percentage of total body fat, FMI and FFMI, and FMI and FFMI percentiles were calculated. Results: FFMI and FMI percentiles for healthy adolescents (both sexes) categorized by age are displayed. In boys a significant increase in FFMI is observed, and both the percentage of total body fat and FMI significantly decreased. In contrast, in girls the percentage of body fat mass, FMI, and FFMI significantly increased. Except at 10 years of age, FMI was higher (p < 0.05) in girls at all ages. FFMI was higher (p < 0.05) in boys at all ages. Conclusions: reference values of FMI and FFMI would be a very useful instrument in clinical practice for the diagnosis and, especially, the analysis of body composition changes during the treatment of childhood obesity.

Assessment of nutritional status in paediatric outpatients using bioelectrical impedance analysis and anthropometric z-scores

AIM

To investigate paediatric outpatients' nutritional status using bioelectrical impedance analysis and anthropometric z-scores.

METHODS

A retrospective data analysis of tertiary paediatric hospital outpatients from 2017 to 2019 was conducted. Patients were categorised into three groups (non-illness, illness and simple obesity) according to clinical diagnoses. The nutritional status was evaluated using anthropometric and bioelectrical impedance analysis. In addition, body composition measurements of patients in three subgroups of the illness group and age- and gender-matched healthy controls were compared.

RESULTS

A total of 2015 paediatric outpatients were enrolled. According to body mass index z-scores, undernutrition prevalence among participants was 14.0% (non-illness group, 21.3%; illness group, 11.4%). Body composition measurements indicated that 41.6% of participants had a low fat-free mass index, and the proportions of participants with a low fat-free mass index in the non-illness, illness and simple obesity groups were 48.4, 47.0 and 10.7%, respectively. Compared with healthy controls, the haematology and oncology subgroup had a significantly lower fat-free mass index and fat mass index; the nephrology and rheumatology subgroup had significantly lower height-for-age z-scores but higher fat mass index; and the gastroenterology subgroups had lower fat mass index, fat-free mass index and body mass index z-scores.

CONCLUSIONS

The results suggested the low fat-free mass index prevalence was greater than the low body mass index z-score prevalence among paediatric outpatients, and body composition parameters varied across different illnesses. Body composition analysis is recommended in nutrition clinics for accurate paediatric outpatient nutritional assessment, thereby providing timely individualised nutritional interventions.

Association between insulin growth factor-1, bone mineral density, and frailty phenotype in children with chronic kidney disease

BACKGROUND

This cohort study investigates the association between insulin growth factor-1 (IGF-1), bone mineral density, and frailty phenotype in children with chronic kidney disease (CKD).

METHODS

Forty-six patients (median age 14.5 years) were prospectively enrolled. Frailty phenotype was defined as the presence ≥ 3 of the following indicators: suboptimal growth/weight gain (body mass index height age < 5th percentile or height < 3rd percentile or loss of ≥ 10 percentiles/year in at least one parameter), low muscle mass (lean tissue mass height age < 5th percentile or loss of ≥ 10 percentiles/year), general fatigue reported by parent or child, and C-reactive protein > 3 mg/l. Lumbar bone mineral apparent density (LBMAD) was measured by dual-energy X-ray absorptiometry, body composition by bioimpedance spectroscopy, and IGF-1 by enzyme-labeled chemiluminescent immunometric assay.

RESULTS

Frailty phenotype (seven patients) was more frequent in advanced CKD (estimated glomerular filtration rate < 30 ml/min/1.73m²) (p = 0.014). IGF-1 and LBMAD z-scores were lower in patients with suboptimal growth/weight gain (14 patients) (p = 0.013, p = 0.012), low muscle mass (nine patients) (p = 0.001, p = 0.009), and general fatigue (eight patients) (p < 0.001, p = 0.004). IFG-1 and LBMAD z-scores were associated with frailty phenotype (OR 0.109, 95% CI 0.015-0.798 and OR 0.277, 95% CI 0.085-0.903) after adjustment for CKD stage. IGF-1 z-score was associated with LBMAD < 5th percentile (six patients) (OR 0.020, 95% CI 0.001-0.450) after adjustment for CKD stage. The association between LBMAD and frailty phenotype lost significance after adjustment for IGF-1.

CONCLUSION

Frailty phenotype is more frequent in advanced pediatric CKD. IGF-1 is negatively associated with frailty phenotype and interferes in the association between frailty and LBMAD.

Growth and Body Composition in PKU Children-A Three-Year Prospective Study Comparing the Effects of L-Amino Acid to Glycomacropeptide Protein Substitutes

Protein quality and quantity are important factors in determining lean body (muscle) mass (LBM). In phenylketonuria (PKU), protein substitutes provide most of the nitrogen, either as amino acids (AA) or glycomacropeptide with supplementary amino acids (CGMP-AA). Body composition and growth are important indicators of long-term health. In a 3-year prospective study comparing the impact of AA and CGMP-AA on body composition and growth in PKU, 48 children were recruited. N = 19 (median age 11.1 years, range 5–15 years) took AA only, n = 16 (median age 7.3 years, range 5–15 years) took a combination of CGMP-AA and AA, (CGMP50) and 13 children (median age 9.2 years, range 5–16 years) took CGMP-AA only (CGMP100). A dual energy X-ray absorptiometry (DXA) scan at enrolment and 36 months measured LBM, % body fat (%BF) and fat mass (FM). Height was measured at enrolment, 12, 24 and 36 months. No correlation or statistically significant differences (after adjusting for age, gender, puberty and phenylalanine blood concentrations) were found between the three groups for LBM, %BF, FM and height. The change in height z scores, (AA 0, CGMP50 +0.4 and CGMP100 +0.7) showed a trend that children in the CGMP100 group were taller, had improved LBM with decreased FM and % BF but this was not statistically significant. There appeared to be no advantage of CGMP-AA compared to AA on body composition after 3-years of follow-up. Although statistically significant differences were not reached, a trend towards improved body composition was observed with CGMP-AA when it provided the entire protein substitute requirement.

Anthropometric Markers and Iron Status of 6-12-Year-Old Thai Children: Associations and Predictors

Introduction

Obesity may be associated with poor iron status. The objective of this study was to investigate the association between different indices of iron status and anthropometric measurements in Thai children.

Materials and Methods

Anthropometry (weight, height, waist circumference (WC), and body composition assessed by bioelectrical impedance analysis) and iron indices were measured in 336 Thai children aged 6-12 years. Iron deficiency (ID) was defined using two or more of the following: (1) %transferrin saturation (%Tsat) < 16%; (2) serum ferritin (SF) < 15 μg/mL; and (3) soluble transferrin receptor (sTfR) > 5 mg/L. Iron deficiency anaemia (IDA) was defined as haemoglobin < WHO age cutoff combined with ID. Overweight and obesity were defined as body mass index (BMI) standard deviation score (SDS) ≥ +1 SDS or +2 SDS, respectively (WHO growth reference).

Results

BMI SDS was significantly positively correlated with sTfR and SF (sTfR, r: 0.209, p < 0.001; SF, r: 0.214, p < 0.001) and negatively correlated with %Tsat (r: -0.132, p = 0.013). Correlations between WC SDS and %fat mass and each iron marker were similar. The percentage with low SF was significantly lower than that using other individual markers. ID prevalence was not significantly different between normal-weight and overweight/obesity groups although a significantly higher proportion of overweight/obese children had sTfR >5 mg/L. Puberty and menarche were significant predictors of ID (puberty adjusted OR: 2.20, 95% CI: 0.43, 11.25; menarche adjusted OR: 6.11, 95% CI: 1.21, 30.94).

Conclusion

Greater adiposity was associated with poorer iron status. However, SF may not be a good indicator of iron status in Thai children, particularly in those who are overweight/obese, whereas sTfR merits further investigation.

Comparison of Bioelectrical Impedance-Based Methods on Body Composition in Young Patients with Obesity

(1) Background: The determination of body composition is an important method to investigate patients with obesity and to evaluate the efficacy of individualized medical interventions. Bioelectrical impedance-based methods are non-invasive and widely applied but need to be validated for their use in young patients with obesity. (2) Methods: We compiled data from three independent studies on children and adolescents with obesity, measuring body composition with two bioelectrical impedance-based devices (TANITA and BIACORPUS). For a small patient group, additional data were collected with air displacement plethysmography (BOD POD) and dual-energy X-ray absorptiometry (DXA). (3) Results: Our combined data on 123 patients (age: 6–18 years, body mass index (BMI): 21–59 kg/m²) and the individual studies showed that TANITA and BIACORPUS yield significantly different results on body composition, TANITA overestimating body fat percentage and fat mass relative to BIACORPUS and underestimating fat-free mass (p < 0.001 for all three parameters). A Bland–Altman plot indicated little agreement between methods, which produce clinically relevant differences for all three parameters. We detected gender-specific differences with both methods, with body fat percentage being lower (p < 0.01) and fat-free mass higher (p < 0.001) in males than females. (4) Conclusions: Both bioelectrical impedance-based methods provide significantly different results on body composition in young patients with obesity and thus cannot be used interchangeably, requiring adherence to a specific device for repetitive measurements to ascertain comparability of data.

Association of Childhood Fat Mass and Weight With Adult-Onset Type 2 Diabetes in Denmark

IMPORTANCE

Childhood obesity, defined by cutoffs based on the weight-based marker of body mass index, is associated with adult type 2 diabetes (T2D) risk. Whether childhood fat mass (FM) is the driver of these associations is currently unknown.

OBJECTIVE

To quantify and compare height-independent associations between childhood FM and weight with adult T2D risk in a historic Danish cohort.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study included schoolchildren from The Copenhagen School Health Records Register born between January 1930 and December 1985 with follow-up to adulthood through December 31, 2015. Analyses were based on 269 913 schoolchildren aged 10 years with 21 896 established adult T2D cases and 261 192 children aged 13 years with 21 530 established adult T2D cases for whom childhood height and weight measurements, as well as predicted FM, were available. Statistical analyses were performed between April 2019 to August 2020.

EXPOSURES

Childhood FM and weight at ages 10 and 13 years.

MAIN OUTCOMES AND MEASURES

Diagnoses of T2D were established by linkage to national disease registers for adults aged at least 30 years. Sex-specific Cox regression quantified associations, adjusted for childhood height, which were evaluated within 5 birth-cohort groups. Group-specific results were pooled using random-effects meta-analyses accounting for heterogeneity across group-specific associations.

RESULTS

This cohort study analyzed data from 269 913 children aged 10 years (135 940 boys [50.4%]) with 21 896 established adult T2D cases and 261 192 children aged 13 years (131 025 boys [50.2%]) with 21 530 established adult T2D cases. After adjusting for childhood height, increases in FM and weight (per kilogram) among boys aged 10 years were associated with elevated T2D risks at age 50 years of 12% (hazard ratio [HR], 1.12; 95% CI, 1.10-1.14) and 7% (HR, 1.07; 95% CI, 1.05-1.09), respectively, and among girls aged 10 years of 15% (HR, 1.15; 95% CI, 1.13-1.17) and 10% (HR, 1.10; 95% CI, 1.08-1.11), respectively. Among children aged 13 years, increases in FM and weight (per kilogram) were associated with increased T2D risks at age 50 years of 10% (HR, 1.10; 95% CI, 1.09-1.10) and 6% (HR, 1.06; 95% CI, 1.05-1.07) for boys, respectively, and of 10% (HR, 1.10; 95% CI, 1.10-1.11) and 7% (HR, 1.07; 95% CI, 1.06-1.08), respectively, for girls.

CONCLUSIONS AND RELEVANCE

This cohort study found that a 1-kg increase in childhood FM was more strongly associated with increased adult T2D risk than a 1-kg increase in weight, independent of childhood height. Information on FM, rather than weight-based measures, focuses on a modifiable component of weight that may be associated with adult T2D risk. These findings support the assessment of childhood FM in adiposity surveillance initiatives in an effort to reduce long-term T2D risk.

Bioelectrical Impedance Phase Angle and Its Determinants in Patients with Classic Congenital Adrenal Hyperplasia

BACKGROUND

Patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH21OHD) have increased fat mass and metabolic alterations. The bioelectrical impedance phase angle (PhA) is an indicator of cellular integrity in several diseases. This study aimed to determine the influence of adiposity levels, sex, CAH21OHD, pubertal development, body composition, and treatment on the PhA of patients with CAH21OHD.

METHODS

Forty girls and 30 boys with CAH21OHD aged 15.3 ± 5.8 years were evaluated. Sexual maturation was assessed by a pediatrician. The PhA was assessed using bioelectrical impedance, percentage of fat mass (% FM), and lean soft tissue (LST) with dual-energy X-ray absorptiometry. Adiposity levels were compared using % FM tertiles and body mass index (BMI). Glucocorticoid dosage was converted using hydrocortisone dose equivalent (HDE).

RESULTS

No differences were found in the PhA values among the clinical form (p = 0.103), BMI (p = 0.498), and % FM (p = 0.654) groups. High PhA values were observed in boys (p = 0.011) and postpubertal (p < 0.001) patients. LST, HDE, and height in girls (r² = 0.68, p < 0.001) and age, HDE, and FM in boys (r² = 0.82, p < 0.001) determined the PhA variations. BMI explained 14% (p = 0.032) of the PhA variations, whereas LST, height, HDE, and FM (kg) explained 66% (p < 0.001) in the prepubertal, pubertal, and postpubertal groups, respectively.

CONCLUSION

LST determined the PhA variations in girls and the postpubertal group. Age and BMI were determinants in boys and the pre- and pubertal groups, respectively.

Micronutrient status influences clinical outcomes of paediatric cancer patients during treatment: A prospective cohort study

BACKGROUND

Research reporting plasma micronutrient status and its impact on clinical outcomes in paediatric cancer is scarce. Therefore, we investigated the prevalence of plasma micronutrient abnormalities and their impact on clinical outcomes and treatment complications.

METHODS

A multicentre prospective-cohort study of children aged <18 years diagnosed with cancer was performed between Aug 2010-Jan 2014. Clinical and nutritional data were collected at diagnosis, 3, 6, 9, 12 and 18 months. Micronutrient status was established using in-house laboratory references (vitamin B12, vitamin A and Vitamin E/Ch) and aged adjusted Z-scores (Mg, Se, Zn and Cu) generated from a cohort of healthy Scottish children. Clinical outcomes were classified as "event free survival (EFS)" or "event" (relapse, death, new metastasis or becoming palliative) and treatment complications. Descriptive statistics, logistic regression and multilevel analysis were performed.

RESULTS

Eighty-two patients [median (IQR) 3.9 (1.9-8.8) years, 56% males] were recruited. Of these, 72 (88%) samples were available, 74% (53/72) patients had micronutrient abnormalities at baseline; deficiencies (25%, 18/72), excesses (19%, 14/72) and a combination of both (29%, 21/72), which continued for 18 months. Vitamin A deficiency (15%, 3/20) and excess (50%, 10/20) were most prevalent at 18 months, whilst vitamin E/Cholesterol and vitamin B12 were mostly within the normal range. Prevalence of Zn deficiency at diagnosis was 36% (16/44 adjusted for CRP), which remained at these levels throughout the study. Reduction in each selenium concentration unit increased the odds of an event by 2% (OR 0.02) and lower Se predicted higher complications at diagnosis [β (-1.2); t (-2.1); 95% CI (-2.9 - (-0.04)); p = 0.04], 3 months [β (-3.9); t (-4.2); 95% CI (-5.57 - (-2.02)); p < 0.001] and 12 months [β (-2.3); t (-2.4); 95% CI (-4.10 - (-0.34)); p = 0.02].

CONCLUSIONS

Given the prevalence of micronutrient abnormalities and the negative impact of low selenium on clinical outcome, micronutrient status should be assessed and monitored in paediatric cancer patients. Larger multicentre population based studies and clinical trials are now warranted.

Growth, body composition, and cardiovascular and nutritional risk of 5- to 10-y-old children consuming vegetarian, vegan, or omnivore diets

BACKGROUND

Plant-based diets (PBDs) are increasingly recommended for human and planetary health. However, comprehensive evidence on the health effects of PBDs in children remains incomplete, particularly in vegans.

OBJECTIVES

To quantify differences in body composition, cardiovascular risk, and micronutrient status of vegetarian and vegan children relative to omnivores and to estimate prevalence of abnormal micronutrient and cholesterol status in each group.

METHODS

In a cross-sectional study, Polish children aged 5-10 y (63 vegetarian, 52 vegan, 72 matched omnivores) were assessed using anthropometry, deuterium dilution, DXA, and carotid ultrasound. Fasting blood samples, dietary intake, and accelerometry data were collected.

RESULTS

All results are reported relative to omnivores. Vegetarians had lower gluteofemoral adiposity but similar total fat and lean mass. Vegans had lower fat indices in all regions but similar lean mass. Both groups had lower bone mineral content (BMC). The difference for vegetarians attenuated after accounting for body size but remained in vegans (total body minus the head: -3.7%; 95% CI: -7.0, -0.4; lumbar spine: -5.6%; 95% CI: -10.6, -0.5). Vegetarians had lower total cholesterol, HDL, and serum B-12 and 25-hydroxyvitamin D [25(OH)D] without supplementation but higher glucose, VLDL, and triglycerides. Vegans were shorter and had lower total LDL (-24 mg/dL; 95% CI: -35.2, -12.9) and HDL (-12.2 mg/dL; 95% CI: -17.3, -7.1), high-sensitivity C-reactive protein, iron status, and serum B-12 (-217.6 pmol/L; 95% CI: -305.7, -129.5) and 25(OH)D without supplementation but higher homocysteine and mean corpuscular volume. Vitamin B-12 deficiency, iron-deficiency anemia, low ferritin, and low HDL were more prevalent in vegans, who also had the lowest prevalence of high LDL. Supplementation resolved low B-12 and 25(OH)D concentrations.

CONCLUSIONS

Vegan diets were associated with a healthier cardiovascular risk profile but also with increased risk of nutritional deficiencies and lower BMC and height. Vegetarians showed less pronounced nutritional deficiencies but, unexpectedly, a less favorable cardiometabolic risk profile. Further research may help maximize the benefits of PBDs in children.

Body composition assessment after pediatric liver transplant

BACKGROUND

Pediatric liver transplantation generally restores metabolic function; yet after transplantation, some children remain malnourished, have increased adiposity, and develop obesity. Measurement of body composition in the assessment of nutrition status could reduce adverse consequences in children.

METHODS

Anthropometric measurements, multiple-frequency bioelectrical impedance analysis, air displacement plethysmography, and ultrasound measurements were conducted on children recruited from the liver transplant program at the University of Minnesota Masonic Children's Hospital. A cross-sectional study was conducted to describe the quality of weight gain in post-liver transplant children between the ages of 2 and 17 years using multiple assessment tools (air displacement plethysmography, multiple-frequency bioelectrical impedance analysis, and ultrasound) and to determine whether multiple-frequency bioelectrical impedance analysis and ultrasound accurately describe body composition and quality of weight gain.

RESULTS

Mean percent body fat by air displacement plethysmography and multiple-frequency bioelectrical impedance analysis was 18.4% (±3.3) and 19.0% (±3.9), respectively (P > .99). There were insufficient data to examine the relationship between summed muscle and adipose thickness measures by ultrasound and percent body fat determined by air displacement plethysmography or multiple-frequency bioelectrical impedance analysis.

CONCLUSION

Percent body fat, fat mass, and fat-free mass measures determined by air displacement plethysmography and multiple-frequency bioelectrical impedance analysis were not statistically different, which suggests the stand-on device used in this study could be a useful body composition assessment tool for the pediatric population.

Can skinfold thickness equations be substituted for bioimpedance analysis in children?

OBJECTIVE

The aim of the present study was to evaluate the agreement between the most used skinfold thickness equations with multi-frequency bioimpedance analysis in the prediction of body fat levels in children.

METHOD

A cross-sectional study of healthy Brazilian community-dwelling individuals. The anthropometric assessment included height, body mass, arm circumference, and waist circumference. The percentage of body fat was obtained by measuring skinfold thickness equations and using bioimpedance analysis, and skinfold thickness was measured using a scientific skinfold caliper. Bland-Altman plot analysis was used to verify the agreement between the methods.

RESULTS

There were 439 children and adolescents evaluated, with a mean age of 11.6±3.7 years. The mean body fat by bioimpedance analysis was 22.8%±10.4%, compared to 22.4%±8.8% by Slaughter (1), 20.4%±9.2% by Slaughter (2), 19.6%±4.4% by Goran, and 24.7%±10.0% by Huang equations. Bland-Altman plot analysis revealed limits of agreement greater than 8% between the bioimpedance analysis approach and equations, exceeding the clinically acceptable limit predefined a priori. None of the equations had good agreement with bioimpedance analysis.

CONCLUSION

It was concluded that skinfold thickness and bioimpedance analysis should not be used interchangeably in children and adolescents.

Association Between Secondary Hyperparathyroidism and Body Composition in Pediatric Patients With Moderate and Advanced Chronic Kidney Disease

Objective: This single center cross-sectional study aims to investigate the association between secondary hyperparathyroidism and body composition in pediatric patients with moderate (stage 3) and advanced (stage 4-5) chronic kidney disease (CKD). Methods: 61 patients (median age: 13.4 years) were included. Body composition indices, including lean tissue index (LTI) and fat tissue index (FTI), were measured using multi-frequency bio-impedance spectroscopy. Muscle wasting was defined as LTI adjusted to height-age (HA) z-score < -1.65 SD and high adiposity as FTI z-score > 1.65 SD. Serum mineral metabolism parameters, including serum intact parathormone (iPTH), calcium, phosphorus and 25-hydroxyvitamin D, as well as serum leptin were measured in each patient. In advanced CKD patients, the mean values of serum mineral laboratory parameters of the 6 months prior to body composition assessment were recorded, and alfacalcidol index, defined as weekly alfacalcidol dose (mcg/week) per pg/ml of iPTH × 1,000, was calculated. Results: In moderate CKD (31 patients), high iPTH (>90 ng/ml) was observed in 10 (32.3%) patients and was associated with higher FTI z-score (p = 0.022). Moreover, serum iPTH was negatively correlated to LTI HA z-score (rs = -0.486, p = 0.006), and positively correlated to serum leptin levels (rs = 0.369, p = 0.041). The positive correlation between FTI z-score and iPTH (rs = 0.393, p = 0.039) lost significance after adjustment for serum leptin. iPTH was positively associated with high adiposity (12 patients, 38.7%) after adjustment for the other mineral metabolism parameters (OR 1.023, 95% CI 1.002-1.045, p = 0.028). In advanced CKD (30 patients), no significant correlation was observed between iPTH and body composition indices and serum leptin levels. Eleven (36.7%) patients with muscle wasting presented lower alfacalcidol index (p = 0.017). Alfacalcidol index ≤ 24 was strongly associated with muscle wasting after adjustment for CKD stage and other mineral metabolism parameters (OR 7.226, 95% CI 1.150-45.384, p = 0.035). Conclusion: Secondary hyperparathyroidism is associated with high adiposity in moderate but not in advanced CKD, with leptin acting as a potential contributive factor. In advanced CKD, targeting higher alfacalcidol weekly dose per each unit of serum PTH seems beneficial for preventing muscle wasting.

Body composition monitoring in children and adolescents: reproducibility and reference values

There is an increasing need for suitable tools to evaluate body composition in paediatrics. The Body Composition Monitor (BCM) shows promise as a method, but reference values in children are lacking. Twenty children were included and measured twice by 4 different raters to asses inter- and intra-rater reproducibility of the BCM. Reliability was assessed using the Bland-Altman method and by calculating intraclass correlation coefficients (ICCs). The intra-rater ICCs were high (≥ 0.97) for all parameters measured by BCM as were the inter-rater ICCs for all parameters (≥ 0.98) except for overhydration (0.76). Consequently, a study was set up in which BCM measurements were performed in 2058 healthy children aged 3-18.5 years. The age- and gender-specific percentile values and reference curves for body composition (BMI, waist circumference, fat mass and lean tissue mass) and fluid status (extracellular and intracellular water and total body water) relative to age were produced using the GAMLSS method for growth curves.Conclusion: A high reproducibility of BCM measurements was found for fat mass, lean tissue mass, extracellular water and total body water. Reference values for these BCM parameters were calculated in over 2000 children and adolescents aged 3 to 18 years. What is Known • The 4-compartment model is regarded as the 'gold standard' of body composition methods, but is inappropriate for regular follow-up or screening of large groups, because of associated limitations. • Body Composition Monitor® is an inexpensive field method that has the potential to be an adequate monitoring tool. What is New • Good reproducibility of BCM measurements in children provides evidence to use the device in longitudinal follow-up, multicentre and comparative studies. • Paediatric reference values relative to age and sex for the various compartments of the body are provided.

Use of standardized body composition measurements and malnutrition screening tools to detect malnutrition risk and predict clinical outcomes in children with chronic conditions

BACKGROUND

Better tools are needed to diagnose and identify children at risk of clinical malnutrition.

OBJECTIVES

We aimed to compare body composition (BC) and malnutrition screening tools (MSTs) for detecting malnutrition on admission; and examine their ability to predict adverse clinical outcomes [increased length of stay (LOS) and complications] in complex pediatric patients.

METHODS

This was a prospective study in children 5-18 y old admitted to a tertiary pediatric hospital (n = 152). MSTs [Pediatric Yorkhill Malnutrition Score (PYMS), Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP), and Screening Tool for Risk of Impaired Nutritional Status and Growth (STRONGkids)] were completed on admission. Weight, height, and BC [fat mass (FM) and lean mass (LM) by DXA] were measured (n = 118). Anthropometry/BC and MSTs were compared with each other and with clinical outcomes.

RESULTS

Subjects were significantly shorter with low LM compared to reference data. Depending on the diagnostic criteria used, 3%-17% were classified as malnourished. Agreement between BC/anthropometric parameters and MSTs was poor. STAMP and STRONGkids identified children with low weight, LM, and height. PYMS, and to a lesser degree STRONGkids, identified children with increased LOS, as did LM compared with weight or height. Patients with complications had lower mean ± SD LM SD scores (-1.38 ± 1.03 compared with -0.74 ± 1.40, P < 0.05). In multivariable models, PYMS high risk and low LM were independent predictors of increased LOS (OR: 3.76; 95% CI: 1.36, 10.35 and OR: 3.69; 95% CI: 1.24, 10.98, respectively). BMI did not predict increased LOS or complications.

CONCLUSIONS

LM appears better than weight and height for predicting adverse clinical outcomes in this population. BMI was a poor diagnostic parameter. MSTs performed differently in associations to BC/anthropometry and clinical outcomes. PYMS and LM provided complementary information regarding LOS. Studies on specific patient populations may further clarify the use of these tools and measurements.

Growth, Body Composition, and Lung Function in Prepubertal Children with Cystic Fibrosis Diagnosed by Newborn Screening

BACKGROUND

Children with cystic fibrosis (CF) are at risk of altered body composition (BC). Newborn screening (NBS) may lead to improved BC outcomes. We investigated BC and its relationship with lung function in prepubertal children diagnosed with CF by NBS. Secondary aims explored predictors of fat-free mass (FFM) and lung function.

METHODS

Thirty-seven screened (non-meconium ileus) children with CF (20 boys) born 2007-2012 had a dual-energy x-ray absorptiometry scan at 5-8 years to determine whole-body (WB) and appendicular BC. Anthropometry was performed and routine spirometry recorded. Results were converted to z-scores, height-adjusted (fat mass index [FMI] and FFM index [FFMI]) and compared with population mean values. Predictors of forced expiratory volume in 1 second (FEV₁ ) were assessed using linear regression.

RESULTS

Height, body mass index (BMI), and FEV₁ were within normal limits, however, weight and BC were significantly low compared with reference data (weight, P = .03; WB FMI, P = .001; WB FFMI, P = .009). Gender differences were detected, with lower appendicular BC in boys and lower weight, BMI, and BC in girls. The association between FEV₁ and WB FFMI (r = 0.38; P = .02) was stronger than with BMI (r = 0.29; P = .08). WB FFMI was the only significant predictor of FEV₁ in a multivariable model (95% CI, 0.11-0.99; P = .016).

CONCLUSION

In this NBS CF population, gender differences in growth and BC were apparent despite preserved lung function. These results support BC assessment in prepubertal children, particularly girls, with an opportunity to direct interventions to optimize FFM.