Validation of body composition using bioelectrical impedance analysis in children according to the degree of obesity

The Influence of Body Composition on Sagittal Plane Posture among Elementary School-Aged Children

Proper posture, characterized by the appropriate alignment of the cervical, thoracic, and lumbar segments of the spine, enables these regions to maintain their normal curvature. Body composition is recognized as one of the factors that can influence overall postural alignment of the spine. The objective of this study was to determine the influence of the parameters of body composition on the prevalence of postural disorders in the sagittal plane. The cross-sectional study was conducted on 152 children of both genders (78 boys), at a mean age of 11 years ± 6 months. In order to evaluate postural disorders, the Formetric 4D System, a tool manufactured by Diers, Schlangenbad, Germany was used. Based on its output data, the following variables were obtained: hyperkyphosis, hyperlordosis, kypholordosis, flatback, and normal alignment of the body in the sagittal plane. The evaluation of body composition parameters was conducted using the InBody 770 device. To determine how body composition influences the postural status of the spinal column, a discriminant analysis was employed. The results showed that approximately 65.8% of children exhibit various types of postural disorders when assessing the alignment of the spine in the sagittal plane. The most prevalent disorder observed was hyperkyphosis, affecting 34.2% of the subjects, followed by kypholordosis at 16.4%. Moreover, the results demonstrated that body composition significantly influences body posture (p = 0.004). An increase in fat mass corresponds to a deviation from normal body posture, whereas an increase in the percentage of skeletal muscle mass and fat-free mass is associated with a reduction in postural abnormalities in the sagittal plane. Considering the results, it is clear that body composition parameters serve as more reliable predictors of the influence on body posture compared to simply calculating the body mass index. Furthermore, it can be concluded that there are consistent patterns of influence by specific body composition parameters, including fat mass, percentage of skeletal muscle, and fat-free mass, on body posture among children from various climates. These results underscore the significance of implementing strength exercises in children, particularly during periods of rapid growth and development, as a means of preventing and correcting postural disorders.

Obesity and Body Composition in Relation to Liver and Kidney Ultrasound Elastography in Paediatric Patients with Either Hypertension or Chronic Kidney Disease

(1) Background: Ultrasound elastography is a novel ultrasound technique for evaluating tissue elasticity. One of the key factors influencing the measurement in children is excess weight. This study aimed to evaluate the effect of body composition, namely, fat mass, on liver and kidney ultrasound elastography in paediatric patients. (2) Methods: 114 participants, in whom bioimpedance, along with liver and kidney ultrasound elastography, were performed, were included (37 patients with chronic kidney disease, 46 patients with hypertension, and 31 healthy subjects). (3) Results: Bioimpedance analysis showed a significant correlation between liver elastography parameters and the phase angle (p = 0.002), fat-free mass (p = 0.001), body cell mass (p = 0.001), total body water (p = 0.001), extracellular water (p = 0.006), and, to lesser extent, fat mass (p = 0.041). On the contrary, kidney elastography parameters strongly correlated only with fat mass (p < 0.001 for both kidneys). (4) Conclusions: Liver and kidney stiffness increased in overweight participants and showed significant correlation with fat mass, particularly in the case of kidney elastography.

Similarities and discrepancies between commercially available bioelectrical impedance analysis system and dual-energy X-ray absorptiometry for body composition assessment in 10-14-year-old children

A variety of easy-to-use commercial bioelectrical impedance appliances are available. The aim of this study was to examine the usefulness of a commercially available body composition meter using bioelectrical impedance analysis (BIA) by comparing its measurement results with those obtained from dual-energy X-ray absorptiometry (DXA). The participants were 443 children aged from 10 to 14 years (226 boys and 217 girls). Fat mass, fat-free mass, lean body mass, percentage of body fat, and bone mineral contents were evaluated for all participants using BIA and DXA. The agreement in the anthropometric data obtained from both devices was analyzed using correlation analysis, intraclass correlation coefficient (ICC), Lin's concordance correlation coefficient (CCC), Bland-Altman plots, and ordinary least products regression analysis. Equivalence between both devices was tested by two one-sided t-test. All measured indicators showed strong linear correlations between the two measurement systems (r, 0.853-1.000). Fat mass, fat-free mass, and lean body mass showed absolute concordance (ICC, 0.902-0.972; Lin's CCC, 0.902-0.972). BIA overestimated bone mineral content (62.7-66.5%) and underestimated percentage of body fat (- 8.9 to - 0.8%), lean body mass (- 3.5 to - 1.8%), and body mass (- 0.8 to - 0.5%). For fat mass and fat-free mass, the overestimate or underestimate varied according to the sex and statistical analysis test. Bland-Altman analysis and ordinary least products analysis showed fixed bias and proportional bias in all indicators. Results according to quartiles of body mass index showed poor agreement for fat mass and percentage of body fat in both boys and girls in the lowest body mass index quartile. The present results revealed strong linear correlations between BIA and DXA, which confirmed the validity of the present single-frequency BIA-derived parameters. Our results suggest that BIA cannot provide the exact same values as DXA for some body composition parameters, but that performance is sufficient for longitudinal use within an individual for daily health management and monitoring.

Association between Maternal Body Composition in Second Trimester and Risk of Fetal Macrosomia: A Population-Based Retrospective Study in China

(1) Background: Female body composition undergoes significant changes to support fetal growth and development during pregnancy. This study investigated the association of maternal body composition in the second trimester and macrosomia and explored whether body-composition-related indicators could be used to predict macrosomia. (2) Methods: This study was conducted in China from December 2016 to December 2021. Women with singleton pregnancies, gestational ages between 37 and 42 weeks, and an absence of pregnancy complications were included. In the second trimester, bioelectric impedance analysis (BIA) was used to measure body-composition-related indicators. Logistic regression analysis was performed to explore the risk factors for macrosomia. The predictive performance of maternal body composition and clinical indicators for macrosomia were assessed using the area under the receiver-operating-characteristics curve (AUC). (3) Results: This retrospective study involved 43,020 pregnant women; we collected 2008 cases of macrosomia. Gravidity, gestational age, body mass index (BMI), gestational weight gain (GWG), total body water, fat mass, fat-free mass (FFM), skeletal muscle mass, and visceral fat level were risk factors for macrosomia (p < 0.05 for all). In the prediction model, the AUC of FFM for predicting macrosomia was the largest (0.742). (4) Conclusions: Body-composition-related indicators associated with macrosomia and body composition measurements in the second trimester can predict the risk of macrosomia, enabling clinicians to implement interventions earlier to reduce adverse perinatal outcomes.

Effect of obesity and excessive body fat on glycaemic control in paediatric type 1 diabetes

OBJECTIVES

Excessive adiposity is believed to contribute to insulin resistance, resulting in more complex metabolic outcomes and poorer glycaemic control. This study aimed to determine the prevalence of overweight/obese, excessive adiposity, and metabolic syndrome in type 1 diabetes mellitus (T1DM) children, who were from a relatively overweight/obese population, and to assess the effects on glycaemic control.

METHODS

A cross-sectional study was conducted from November 2019 to August 2020 on T1DM children between 6 and 18 years old who attended the Paediatric Endocrine Clinic Putrajaya Hospital. Anthropometry and bioelectrical impedance analysis (Inbody 720) were measured to analyse their effects towards glycated haemoglobin (HbA_1c) via SPSS 21.

RESULTS

A total of 63 T1DM were recruited with an equal male-to-female ratio. The mean age was 12.4 ± 3.3 years old with a mean HbA_1c of 9.8 ± 2.0%. The prevalence of overweight/obese and excessive body fat was 17.5 and 34.9%, respectively. Only 3 (6.8%) fulfilled the metabolic syndrome criteria. The waist circumference had a significant relationship with HbA_1c. Every 10 cm increment of waist circumference was predicted to raise HbA_1c by 0.8. The odds ratio of having abdominal obesity among T1DM with excessive body fat was 9.3 times.

CONCLUSIONS

Abdominal obesity is significantly associated with a poorer glycaemic control in T1DM children. Monitoring of waist circumference should be considered as part of the routine diabetic care.

Changes in body mass index during treatment of childhood acute lymphoblastic leukemia with the Nordic ALL2008 protocol

OBJECTIVES

Children with acute lymphoblastic leukemia (ALL) have a tendency to gain weight during treatment. As overweight and obesity associate with health problems, prophylactic interventions are warranted. Therefore, it is important to identify the children most prone to gain weight.

METHODS

Patients aged 2.0-17.9 years at ALL diagnosis were identified from the NOPHO ALL2008 registry. Registry data was complemented with height and weight at the end of therapy from questionnaires. Body mass index (BMI) was classified according to international age- and sex-adjusted International Obesity Task Force BMI cut-offs. BMI values were transformed into standard deviation scores (SDS) to calculate the difference in BMISDS during treatment.

RESULTS

Data on BMI change were available for 765 children. Overweight and obesity doubled during treatment: 9.7% were overweight and 2.1% obese at diagnosis and 21.8% and 5.4% at the end of therapy, respectively. The mean BMISDS change was +0.64. Younger (2.0-5.9 years) and healthy weight children were most prone to become overweight (mean change in BMI SDS +0.85 and + 0.65, respectively).

CONCLUSIONS

Younger children (2.0-5.9 years) with healthy weight at diagnosis were most prone to becoming overweight and therefore are an important group to target while considering interventions.

Safety and efficacy of exercise training in children and adolescents with congenital heart disease: A systematic review and descriptive analysis

BACKGROUND

While exercise training is beneficial in the prevention and management of many chronic diseases, the role of exercise training in children and adolescents with congenital heart disease is less understood. We sought to determine the safety and efficacy of exercise training in children and adolescents with congenital heart disease.

METHODS

We conducted a systematic search of the following databases: PubMed, CINAHL, EMBASE, Web of Science and SportDiscus. We included randomised controlled trials that incorporated an exercise intervention compared with a non-exercising comparator group and examined safety and efficacy in children and adolescents with congenital heart disease. A descriptive analysis of the included trials was then conducted.

RESULTS

A total of 9 articles from 6 trials (642 participants with varying conditions and disease severity) were included. Significant variability of study participants and outcomes were observed across the trials. No adverse events linked to the exercise interventions were stated. The articles reported numerous positive changes to clinically relevant fitness measures. Exercise capacity improved with exercise training in 3 of 4 trials in which it was measured. Cardiorespiratory fitness showed improvements in 3 of 4 trials. Neuromuscular fitness increased in 1 of 2 trials. Physiological and metabolic parameters were improved, and negative changes were not observed to several clinically important measures (e.g. muscular oxygenation, cardiac measures) in 2 of 2 trials. Physical activity increased in 1 of 3 trials. No articles reported on changes in measures of body composition. Outcomes are varied with little consensus on measurements or assessment methods.

CONCLUSIONS

Exercise training appears to be safe and efficacious for improving physical fitness in children and adolescents with congenital heart disease who have been appropriately screened by their medical team. However, the certainty of the evidence for these findings is low to moderate.

The Role of Dietary Patterns and Dietary Quality on Body Composition of Adolescents in Chinese College

There is limited evidence regarding the effects of dietary pattern and dietary quality on the risk of unhealthy weight status and related body composition in Chinese adolescence. In particular, studies using bioelectrical impedance analyzer (BIA) in these subjects are rare. The aim of this study was to evaluate the role of diet in body composition, to find a healthy dietary pattern for Chinese youth, and to promote the application of BIA among this population. A total of 498 participants aged from 18 to 22 years old were included. Dietary patterns were identified by principal components analysis. Energy-adjusted dietary inflammatory index (DII) and diet balance index (DBI) were calculated based on semi-quantitative food frequency questionnaire. Multivariate linear regression and logistic regression analysis were used to examine the relationship of dietary patterns, dietary quality with body mass index (BMI), fat mass index (FMI), fat-free mass index (FFMI), and the effect of dietary factors on BMI levels. The majority of participants with overweight and obesity had abdominal obesity, and there was 3.7% abdominal obesity in normal BMI individuals. Four dietary patterns were detected in the subjects. The pattern with the higher energy intake, which was close to the Western diet, was positively correlated with BMI (β = 0.326, p = 0.018) and FMI (β = 0.201, p = 0.043), while being negatively correlated with FFMI (β = −0.183, p = 0.021). Individuals who followed the pattern similar to the Mediterranean diet had a higher basal metabolic rate (BMR), and the highest fat free mass, soft lean mass, and skeletal muscle mass (p < 0.05) but the lowest FMI, visceral fat area (VFA), waist−hip ratio, and FMI/FFMI ratio (p < 0.05). Higher energy-adjusted DII was associated with high BMI. Higher bound score (HBS) (β = −0.018, p = 0.010) and diet quality distance (DQD) (β = −0.012, p = 0.015) were both negatively correlated with FFMI. In conclusion, fat or muscle indexes, such as BMR, FMI, and FFMI, had an important role in predicting overweight and obesity, which suggested the importance of applying BIA among Chinese college students. Students who followed healthful dietary patterns or the high-quality diet that is similar to the Mediterranean diet but not close to the Western diet were more likely to have a healthy BMI and normal body composition.

The impact of an early intervention home-based program on body composition in preterm-born preschoolers with very low birth weight

Background and aims

Early child interventions focused on the family prevented neurodevelopmental and behavioral delays and can provide more knowledge regarding responsive feeding, thus creating learning opportunities to promote better quality nutrition and preventing failure to thrive. The aim is to verify the impact of a continuous program of early home-based intervention on the body composition of preschool infants who were born preterm with very low birth weight (VLBW).

Methods

This is a longitudinal analysis from a randomized controlled trial, including VLBW preterm children, born in a tertiary hospital in Southern Brazil and followed up at the high-risk institutional ambulatory clinic. Participants were divided into the intervention group (IG): skin-to-skin care with the mother (kangaroo care), breastfeeding policy, and tactile-kinesthetic stimulation by mothers until hospital discharge. Subsequently, they received a program of early intervention with orientation and a total of 10 home visits, independently from the standard evaluation and care that was performed following the 18 months after birth; conventional group (CG): standard care according to the routine of the newborn intensive care unit (NICU), which includes kangaroo care, and attending to their needs in the follow-up program. Body composition estimation was performed using bioelectrical impedance analyses (BIA), and physical activity and feeding practices questionnaires were evaluated at preschool age, as well as anthropometric measurements and biochemical analysis.

Results

Data of 41 children at 4.6 ± 0.5 years old were evaluated (CG n = 21 and IG n = 20). Body weight, height, body mass index, waist and arm circumferences, and triceps and subscapular skinfold did not differ between groups. The IG presented higher segmented fat-free mass (FFM) when compared to the CG (right arm FFM: 0.74 vs. 0.65 kg, p = 0.040; trunk FFM: 6.86 vs. 6.09 kg, p = 0.04; right leg FFM: 1.91 vs. 1.73 kg, p = 0.063). Interaction analyses showed that segmented FFM and FFM Index were associated with higher iron content in the IG. In the CG, interaction analyses showed that increased visceral fat area was associated with higher insulin resistance index.

Conclusion

An early intervention protocol from NICU to a home-based program performed by the mothers of VLBW preterm children of low-income families presents a small effect on FFM.

Body Composition and Anthropometric Indicators in Children and Adolescents 6-15 Years Old

The problem of overweight and obesity among children and adolescents has now become a major public health challenge worldwide. The aim of this study was to assess the effect of age and gender on body composition components and anthropometric indices of children and adolescents aged 6-15 years; in addition, the study aimed to assess body composition indices in relation to BMI (Body Mass Index) levels. The study was conducted at the end of 2019 and in the first quarter of 2020 among 181 pupils attending primary schools. Waist circumference, hip circumference, body weight, and body height were measured. The collected data were used to calculate and then to analyse BMI, WHR (Waist-Hip Ratio), and WHtR (Waist to Height Ratio) indices. Body composition was determined with the use of the Bioelectrical Impedance Analysis (BIA). The analyses' statistics were performed using IBM SPSS Statistics 24 and Excel. The statistical methods used included Chi² tests of independence, one-factor analysis of variance, and two-factor analysis of variance taking into account the level of α = 0.05. Based on the results, there were no statistically significant differences in the gender and age distributions of the BMI groups. However, the analysis of interaction effects confirmed that there were statistically significant differences according to pubertal age and gender in body fat, muscle mass, hydration, and WHR. Body composition in boys and girls before the age of 12 is similar while, after the age of 12, there are differences between boys and girls in terms of body composition so there is a need to deepen the assessment of body mass, especially in adolescents at the age of puberty, by body composition analysis using the BIA method.

The relevance of left ventricular functions to clinical and metabolic characteristics of prepubertal children with obesity

BACKGROUND

Paediatric obesity is a worldwide health burden, with growing evidence linking obesity to myocardial function impairments. The study aims to evaluate left ventricular functions among prepubertal obese children to obesity-related clinical and metabolic parameters.

METHODS

Between June 2019 and March 2020, 40 prepubertal children with obesity were recruited and compared to 40 healthy controls. Patients were assessed for body mass index z scores, waist circumference, body adiposity by bioimpedance analysis, and obesity-related laboratory tests, for example, serum chemerin. Left ventricular functions were assessed using variable echocardiographic modalities, such as M-mode, tissue Doppler, and two-dimensional speckle tracking.

RESULTS

Mean patients' age was 9.25 ± 1.05 years. Left ventricular mass index, E/E', and myocardial performance index were significantly increased in obese children than controls. Although M-mode-derived ejection fraction was comparable in both groups, two-dimensional speckle tracking-derived ejection fraction, global longitudinal strain, and global circumferential strain were significantly lower in cases than controls. Left ventricular mass index displayed a positive correlation with body mass index z score (p = 0.003), fat mass index (p = 0.037), and trunk fat mass (p = 0.021). Global longitudinal strain was negatively correlated with body mass index z score (p = 0.015) and fat mass index (p = 0.016). Serum chemerin was positively correlated with myocardial performance index (p = 0.01).

CONCLUSION

Alterations of left ventricular myocardial functions in prepubertal obese children could be detected using different echocardiographic modalities. Chemerin, body mass index z score, fat mass index, and trunk fat mass were correlated with subclinical left ventricular myocardial dysfunction parameters before puberty. Our results reinforce early and strict management of childhood obesity upon detection of changes in anthropometric and body adiposity indices.

Predictors of non-alcoholic fatty liver disease in children

OBJECTIVE

Abdominal obesity is strongly associated with the development of non-alcoholic fatty liver disease (NAFLD). Early identification and intervention may reduce the risk. We aim to improve pediatric NAFLD screening by comparing discriminative performance of six abdominal obesity indicators.

METHODS

We measured anthropometric indicators (waist circumference [WC], waist-to-hip ratio [WHR], waist-to-height ratio [WHtR]), body composition indicators (trunk fat index [TFI], visceral fat area [VFA]), and endocrine indicator (visceral adiposity index [VAI]) among 1350 Chinese children aged 6-8 years. Using Spearman correlation, receiver operating characteristic (ROC) curves, and Logistic regression, we validated their ability to predict NAFLD.

RESULTS

All six indicators can predict NAFLD robustly, with area under the curve (AUC) values ranged from 0.69 to 0.96. TFI, WC, and VFA rank in the top three for the discriminative performance. TFI was the best predictor with AUC values of 0.94 (0.92-0.97) and 0.96 (0.92-0.99), corresponding to cut-off values of 1.83 and 2.31 kg/m² for boys and girls, respectively. Boys with higher TFI (aOR = 13.8), VFA (aOR = 11.1), WHtR (aOR = 3.1), or VAI (aOR = 2.8), and girls with higher TFI (aOR = 21.0) or VFA (aOR = 17.5), were more likely to have NAFLD.

CONCLUSION

User-friendly body composition indicators like TFI can identify NAFLD and help prevent the progress of liver disease.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR) ( www.chictr.org.cn/enIndex.aspx , No. ChiCTR2100044027); retrospectively registered on 6 March 2021.

IMPACT

Abdominal obesity increases the risk of pediatric non-alcoholic fatty liver disease (NAFLD). This study compared the discriminative performance of multiple abdominal obesity indicators measured by different methods in terms of accuracy and fastidious cut-off values through a population-based child cohort. Our results provided solid evidence of abdominal obesity indicators as an optimal screening tool for pediatric NAFLD, with area under the curve (AUC) values ranged from 0.69 to 0.96. User-friendly body composition indicators like TFI show a greater application potential in helping physicians perform easy, reliable, and interpretable weight management to prevent the progress of liver damage.

Analysis of Dietary Habits and Nutritional Status of Children with Down Syndrome in the Context of Lipid and Oxidative Stress Parameters

Introduction: The risk of obesity in children with Down syndrome is high. Undoubtedly, proper nutrition plays an important role in the prevention of excess body weight and is associated with a reduction of metabolic complications. The aim of the study was to assess the problem of disturbances in the nutritional status and eating habits of children with DS. Methods: A total of 39 patients were included in the study. The nutritional status was assessed by anthropometric tests and Dual X-ray Absorptiometry. Eating habits were assessed using the Child Eating Behavior Questionnaire and the Food Frequency Questionnaire. Blood samples were taken to determine the oxidative stress and lipid parameters. Results: Obesity was recognized in 15% of subjects and 23% were overweight. Children that were overweight were characterized by higher levels of triglycerides, atherogenic index of plasma, and apoA2 and apoE levels. Fat mass, fat mass/height² index, and visceral fat mass correlated with thiobarbituric acid reactive substances and advanced oxidative protein product level. The analysis of the Child Eating Behavior Questionnaire showed that children struggling with being overweight were more interested in food compared to those with normal body weight. A positive correlation was identified between waist circumference and food interest categories. Insufficient consumption of dairy products, vegetables, whole grain products, as well as fruits, seeds, nuts, and fatty fish was noted. Patients were less likely to consume products that are a good source of mono- and polyunsaturated fatty acids. Conclusions: In children with Down syndrome and obesity, disturbances in lipid and oxidative stress parameters are observed. Abnormal eating habits in all children with Down syndrome regardless of their nutritional status were noted. Proper nutritional education, nutritional control, and management of metabolic problems are essential in this group of patients.

Association between Cardiopulmonary Capacity and Body Mass Composition in Children and Adolescents with High Body Weight: A Cross-Sectional Study

(1) Background: Excessive body weight is a global problem in the 21st century. Children and adolescents, in particular, are at risk. Recently, there has been an increasing interest in the relationship between aerobic capacity and body composition. Therefore, this study aimed to determine the association between the individual parameters of cardiopulmonary capacity obtained in cardiopulmonary exercise testing (CPET) and selected parameters of body mass composition in high-BMI children and children over the 85th percentile according to the WHO growth reference. (2) Materials and Method: The research included 100 children of school-age (7–15 years) with an excessive BMI, i.e., over the 85th percentile as per the WHO Growth Reference (BMI percentile 95.21 ± 4.65; Z-score BMI: 2.07 ± 0.94). The study consisted of three parts: anthropometric measurements, measurement of body mass composition using a body composition analyzer (TANITA MC-780 S MA) using the bioimpedance method, and a cardiopulmonary exercise test on a pediatric cycle ergometer (Corival Pediatric, Lode BV) using the Godfrey protocol; (3) Results: The correlation between BMI and fat mass (FM) was very high (rho = 0.83; p = 0.00) with moderate body fat percentage (BF%) (rho = 0.48; p = 0.00). There was a relevant correlation between the amount of fat-free mass in total body mass and cardiopulmonary capacity expressed as the absolute aerobic capacity (VO_2peak) (rho = 0.55; p = 0.00). (4) Conclusions: In the case of children and youth with higher BMI, there was a correlation between the amount of fat-free mass in total body mass and cardiopulmonary capacity in terms of absolute aerobic capacity.

Sedentary Time and Fast-Food Consumption Associated With Weight Gain During COVID-19 Lockdown in Children and Adolescents With Overweight or Obesity

BACKGROUND

The coronavirus disease pandemic is predicted to have adverse health effects on children and adolescents who are overweight or obese due to restricted school activity and stay-at-home orders. The purpose of this observational study was to determine the factors associated with weight gain in children and adolescents with overweight and obesity during coronavirus disease 2019 (COVID-19) lockdown.

METHODS

Ninety-seven participants (sex- and age-specific body mass index (BMI) ≥ 85th percentile) were included. A baseline examination was conducted pre-COVID-19 (August 2019 to January 2020), and re-examination was performed post-lockdown (June to September 2020) and the results were compared. Correlation and regression analyses were conducted to investigate the association among changes in cardiometabolic markers and lifestyle behaviors with changes in BMI z-score.

RESULTS

During the COVID-19 pandemic, an increase in BMI z-score (2.56 [2.01-2.94] to 2.62 [2.03-3.18]) was noticed in children and adolescents with obesity. Changes in cardiometabolic markers including liver enzymes, triglycerides (r = 0.398), leptin (r = 0.578), and adiponectin (r = -0.326), as well as muscular strength (r = -0.212), were correlated with the increase in BMI z-score. According to a multivariate regression analysis, changes in sedentary time (B = 0.016; 95% confidence interval [CI], 0.001-0.032) and fast-food consumption (B = 0.067; 95% CI, 0.013-0.122) were the lifestyle variables associated with BMI z-score increase.

CONCLUSION

Changes in lifestyle behaviors including fast-food consumption and sedentary time during the COVID-19 pandemic may be associated with weight gain. In order to prevent health-related risks in children and adolescents with obesity during the pandemic, it is important to maintain the level of physical activity and healthy dietary habits.

Metabolomic Signatures for the Effects of Weight Loss Interventions on Severe Obesity in Children and Adolescents

Childhood obesity has increased worldwide, and many clinical and public interventions have attempted to reduce morbidity. We aimed to determine the metabolomic signatures associated with weight control interventions in children with obesity. Forty children from the “Intervention for Children and Adolescent Obesity via Activity and Nutrition (ICAAN)” cohort were selected according to intervention responses. Based on changes in body mass index z-scores, 20 were responders and the remaining non-responders. Their serum metabolites were quantitatively analyzed using capillary electrophoresis time-of-flight mass spectrometry at baseline and after 6 and 18 months of intervention. After 18 months of intervention, the metabolite cluster changes in the responders and non-responders showed a difference on the heatmap, but significant metabolites were not clear. However, regardless of the responses, 13 and 49 metabolites were significant in the group of children with obesity intervention at 6 months and 18 months post-intervention compared to baseline. In addition, the top five metabolic pathways (D-glutamine and D-glutamate metabolism; arginine biosynthesis; alanine, aspartate, and glutamate metabolism; TCA cycle (tricarboxylic acid cycle); valine, leucine, and isoleucine biosynthesis) including several amino acids in the metabolites of obese children after 18 months were significantly changed. Our study showed significantly different metabolomic profiles based on time post obesity-related intervention. Through this study, we can better understand and predict childhood obesity through metabolite analysis and monitoring.

Degree of Accuracy of the BMI Z-Score to Determine Excess Fat Mass Using DXA in Children and Adolescents

Obesity is caused by fat accumulation. BMI Z-score is used to classify the different degrees of weight status in children and adolescents. However, this parameter does not always express the true percentage of body fat. Our objective was to determine the degree of agreement between the fat mass percentage measured by DXA and the stratification of weight according to BMI Z-score in the pediatric age group. We designed a descriptive cross-sectional study. The patients were classified as underweight/normal weight with Z-scores between −2 and +0.99, overweight from 1 to 1.99, obese from 2 to 2.99, and very obese ≥3. We included 551 patients (47% girls), with a mean age of 11.5 ± 2.8 years (3.7–18 years). Higher BMI Z-scores were associated with a higher percentage of total fat (p < 0.001). However, there were important overlaps between both parameters, such that the BMI Z-score classified patients with the same percentage of total fat mass as having a different nutritional status classification. In conclusion, the stratification of weight status according to BMI Z-score revealed that 46.7% of patients had a fat percentage that did not correspond to their classification. For a more accurate weight assessment in clinical practice, we recommend combining anthropometric indices with diagnostic tools that better correlate with DXA, such as electrical bioimpedance.

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.

New bioelectrical impedance analysis equations for children and adolescents based on the deuterium dilution technique

BACKGROUND AND AIMS

Body composition in childhood is not only a marker of the prevalence of obesity, but it can also be used to assess associated metabolic complications. Bioelectrical impedance analysis (BIA) shows promise as an easy to use, rapid, and non-invasive tool to evaluate body composition. The objectives of this study were to: (a) develop BIA prediction equations to estimate total body water (TBW) and fat-free mass (FFM) in European children and early adolescents and to validate the analysis with the deuterium dilution as the reference technique and (b) compare our results with previously published paediatric BIA equations.

METHODS

The cohort included 266 healthy children and adolescents between 7 and 14 years of age, 46% girls, in five European countries: Bosnia and Herzegovina, Latvia, Montenegro, North Macedonia, and Portugal. TBW and FFM were the target variables in the developed regression models. For model development, the dataset was randomly split into training and test sets, in 70:30 ratio, respectively. Model tuning was performed with 10-fold cross-validation that confirmed the unbiased estimate of its performance. The final regression models were retrained on the whole dataset.

RESULTS

Cross-validated regression models were developed using resistance index, weight, and sex as the optimal predictors. The new prediction equations explained 87% variability in both TBW and FFM. Limits of agreement between BIA and reference values, were within ±17% of the mean, (-3.4, 3.7) and (-4.5, 4.8) kg for TBW and FFM, respectively. BIA FFM and TBW estimates were within one standard deviation for approximately 83% of the children. BIA prediction equations underestimated TBW and FFM by 0.2 kg and 0.1 kg respectively with no proportional bias and comparable accuracy among different BMI-for-age subgroups. Comparison with predictive equations from published studies revealed varying discrepancy rates with the deuterium dilution measurements, with only two being equivalent to the equations developed in this study.

CONCLUSIONS

The small difference between deuterium dilution and BIA measurements validated by Bland-Altman analysis, supports the application of BIA for epidemiological studies in European children using the developed equations.

Validation of bioelectrical impedance analysis for body composition assessment in children with obesity aged 8-14y

BACKGROUND & AIMS

The aim was to generate a predictive equation to assess body composition (BC) in children with obesity using bioimpedance (BIA), and avoid bias produced by different density levels of fat free mass (FFM) in this population.

METHODS

This was a cross-sectional validation study using baseline data from a randomized intervention trial to treat childhood obesity. Participants were 8 to 14y (n = 315), underwent assessments on anthropometry and BC through Air Displacement Plethysmography (ADP), Dual X-Ray Absorptiometry and BIA. They were divided into a training (n = 249) and a testing subset (n = 66). In addition, the testing subset underwent a total body water assessment using deuterium dilution, and thus obtained results for the 4-compartment model (4C). A new equation to estimate FFM was created from the BIA outputs by comparison to a validated model of ADP adjusted by FFM density in the training subset. The equation was validated against 4C in the testing subset. As reference, the outputs from the BIA device were also compared to 4C.

RESULTS

The predictive equation reduced the bias from the BIA outputs from 14.1% (95%CI: 12.7, 15.4) to 4.6% (95%CI: 3.8, 5.4) for FFM and from 18.4% (95%CI: 16.9, 19.9) to 6.4% (95% CI: 5.3, 7.4) for FM. Bland-Altman plots revealed that the new equation significantly improved the agreement with 4C; furthermore, the observed trend to increase the degree of bias with increasing FM and FFM also disappeared.

CONCLUSION

The new predictive equation increases the precision of BC assessment using BIA in children with obesity.

A cross-sectional study of the impact of school neighbourhood on children obesity and body composition

Schools' neighbourhoods provide an important environmental context that may influence the risk of obesity among children. The aim of this study was to assess the effect of neighbourhood surrounding schools on obesity and body composition in schoolchildren. Data on 845 children aged 7 to 12 years old from 20 primary schools were considered. Anthropometric measurements and bioelectrical impedance analysis were performed to assess body mass index (BMI) and characterize body composition. Land use characteristics were quantified within a 500-m buffer zone around schools. Mixed-effect models measured the effects of school neighbourhood on obesity and body composition. The results showed a tendency between green urban areas around schools and lower values of BMI and better body composition parameters compared with built areas, being BMI z-scores CDC, and body fat percentage significantly higher in-built than in green urban areas (β = 0.48, 95% CI 0.05; 0.90, and β = 2.56, 95% CI 0.39; 4.73, respectively).Conclusion: Our findings suggest that the school neighbourhood has an effect on BMI and body fat percentage in schoolchildren. These results may contribute to the creation of healthier cities and help reduce health expenses by focusing on prevention programmes towards the expansion of green spaces. What is Known: • Living in greener areas has been associated with healthy weight outcomes and to the lower impact of obesogenic urban environments. • The school environment may be especially important for youth health outcomes. What is New: • Neighbourhoods around schools may affect child health, specifically the development of obesity. • The presence of urban green areas around school may promote a framework of lifestyle or behaviours conducive to achieving a healthy weight.

Effects of circuit training or a nutritional intervention on body mass index and other cardiometabolic outcomes in children and adolescents with overweight or obesity

Objective

We aimed to assess the effectiveness of the first 6 months of a 24 month multidisciplinary intervention program including circuit training and a balanced diet in children and adolescents with obesity.

Methods

A quasi-experimental intervention trial included 242 participants (age [mean±standard deviation]: 11.3±2.06 years, 97 girls) of at least 85th percentile of age- and sex-specific body mass index (BMI). Participants were grouped into three to receive usual care (usual care group), exercise intervention with circuit training (exercise group), or intensive nutritional and feedback intervention with a balanced diet (nutritional group). Primary outcome was BMI z-score, while secondary outcomes included body composition, cardiometabolic risk markers, nutrition, and physical fitness.

Results

Among the participants, 80.6% had a BMI ≥ the 97th percentile for age and sex. The BMI z-score of the overall completers decreased by about 0.080 after 6 months of intervention (p < 0.001). After the intervention, both exercise and nutritional groups had significantly lower BMI z-scores than the baseline data by about 0.14 and 0.075, respectively (p < 0.05). Significant group by time interaction effects were observed between exercise versus usual care group in BMI z-score (β, -0.11; 95% confidence interval (CI), -0.20 to -0.023) and adiponectin (β, 1.31; 95% CI, 1.08 to 1.58); and between nutritional versus usual care group in waist circumference (β, -3.47; 95% CI, -6.06 to -0.89). No statistically significant differences were observed in any of the other secondary outcomes assessed.

Conclusion

Multidisciplinary intervention including circuit training and a balanced diet for children and adolescents with obesity reduced the BMI z-score and improved cardiometabolic risk markers such as adiponectin and waist circumference.

Body Composition and Exercise Performance in Youth With a Fontan Circulation: A Bio-Impedance Based Study

Background Adults with a Fontan circulation tend to have myopenia and elevated adiposity when measured by dual energy x-ray absorptiometry. Bioelectrical impedance analysis is an alternative validated approach to assess body composition. We used bioelectrical impedance analysis to compare body composition between pediatric patients with a Fontan circulation and control individuals without heart disease. Methods and Results A retrospective chart review identified all patients aged <22 years with a Fontan circulation who presented for cardiopulmonary exercise testing and bioelectrical impedance analysis from April 2019 to January 2020. Data were compared with control subjects tested during the same period. We studied 47 patients with a Fontan circulation (53% boys; 15±3.1 years) and 165 controls (48% boys; 14.4±2.5 years). Fontan status was associated with shorter height, but similar age, sex, and overall body mass. Patients with Fontan had lower lean body mass (-12.0±22%, Z-score -0.5±1, P=0.005), skeletal muscle mass (-13.6±1.4%; Z-score, -0.5±1; P=0.004), skeletal muscle indexed to height (-10.3±13.3%; Z-score, -0.5±1; P=0.005), and higher percent body fat (+13.8±18.6%; Z-score, 0.4±1.2; P=0.03). Greater skeletal muscle mass was associated with higher peak oxygen consumption (r2=0.52, P<0.0001) and oxygen pulse (r2=0.68, P<0.0001). Patients who had suffered a late complication (ie, heart transplant referral or evidence of extracardiac organ dysfunction) of the Fontan operation (13 of 47, 27.7%) had lower skeletal muscle mass (P=0.048) and higher body fat percentage (P=0.003). Conclusions The Fontan circulation is associated with marked myopenia and increased adiposity. Higher muscle mass was associated with better exercise capacity. Fontan complications are associated with lower muscle mass and increased adiposity.

A multidisciplinary weight loss intervention in obese adolescents with and without sleep-disordered breathing improves cardiometabolic health, whether SDB was normalized or not

OBJECTIVES

Pediatric obesity and sleep-disordered breathing (SDB) are strongly associated, and both promote metabolic impairments. However, the effects of a lifestyle intervention on the overall metabolic syndrome (MetS) are unknown. The objectives were i) to evaluate the effects of a lifestyle intervention on cardiometabolic risk (CMR), assessed with a dichotomous (MetS) and a continuous (MetScore_FM) instrument, in obese adolescents with and without SDB and ii) to compare the post-intervention cardiometabolic responses between adolescents with persistent (apnea-hypopnea index; AHI≥2) or normalized-SDB (AHI<2).

METHODS

Seventy-six adolescents with obesity recruited from two specialized institutions underwent a 9-12month diet and exercise intervention. Sleep and SDB (AHI≥2) were studied by polysomnography. Anthropometric parameters, fat mass (FM), glucose, insulin, lipid and leptin profiles, blood pressure (BP), MetScore_FM and MetS were assessed pre- and post-intervention. We performed comparisons between Non-SDB and SDB groups and between Normalized-SDB and Persistent-SDB subgroups.

RESULTS

Fifty participants completed the study. Pre-intervention, twenty youth had SDB (40%) with higher insulin concentrations and systolic BP than Non-SDB participants (p < 0.01), for a similar degree of obesity. Post-intervention, MetScore_FM (p < 0.001) and MetS prevalence (p < 0.05) were decreased in both groups. Eleven participants (55%) normalized SDB along with a decrease in insulin concentrations and BP (p < 0.05). Triglycerides, total cholesterol and LDL-cholesterol concentrations (p < 0.01) improved equally in the Normalized and Persistent-SDB subgroups.

CONCLUSION

SDB was associated with lower insulin sensitivity and higher BP but did not affect the lipid profile. A diet and exercise lifestyle intervention is effective in decreasing the CMR whether or not SDB was normalized in obese adolescents.

Reference values and secular trends for cardiorespiratory fitness in children and adolescents with obesity

AIM

To present specific reference values for cardiorespiratory fitness (CRF) in children with obesity and to analyse secular trends of CRF in the studied population.

METHODS

Cardiorespiratory fitness, the maximal oxygen uptake (VO₂ max), was estimated with the Åstrand-Rhyming submaximal bicycle test, in 705 Swedish children (356 girls, 8-20 years) with obesity according to the International Obesity Task Force (IOTF). Data were collected from 1999 to 2013. Secular trends, analysed with multiple linear regression, were adjusted for age, height and body mass index standard deviation score (BMI SDS).

RESULTS

All children had low CRF compared with normal weight standards but there was a marked variability of CRF in children with obesity, which was possible to quantify with the developed obesity specific CRF reference values. The mean value of absolute VO₂ max (L/min) increased with age and relative VO₂ max (mL/kg/min) decreased with age in both boys and girls. There was a negative secular trend in both sexes (P < .001).

CONCLUSION

These are the first obesity specific reference values of CRF in children enabling clinical evaluation in childhood obesity treatment. Cardiorespiratory fitness in children with obesity has declined the last decades, indicating that also within this vulnerable group physical activity has gone down.

Assessment of body composition in pediatric overweight and obesity: A systematic review of the reliability and validity of common techniques

Accurate measurement of body composition is required to improve health outcomes in children and adolescents with overweight or obesity. This systematic review aimed to summarize the reliability and validity of field and laboratory body composition techniques employed in pediatric obesity studies to facilitate technique selection for research and clinical practice implementation. A systematic search in MEDLINE (via PubMed), EMBASE, CINAHL, and SPORTDiscus from inception up to December 2019 was conducted, using a combination of the following concepts: body composition, pediatric overweight/obesity, and reliability/validity. The search strategy resulted in 66 eligible articles reporting reliability (19.7%), agreement between body composition techniques cross sectionally (80.3%), and/or diagnostic test accuracy (10.6%) in children and adolescents with overweight or obesity (mean age range = 7.0-16.5 years). Skinfolds, air-displacement plethysmography (ADP), dual-energy X-ray absorptiometry (DXA), and ultrasound presented as reliable techniques. DXA, ADP, and isotope dilution showed similar and the best agreement with reference standards. Compared with these laboratory techniques, the validity of estimating body composition by anthropometric equations, skinfolds, and BIA was inferior. In conclusion, the assessment of body composition by laboratory techniques cannot be replaced by field techniques due to introduction of measurement errors, which potentially conceal actual changes in body components.

Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health?

BACKGROUND AND AIMS

Pediatric obesity and sleep-disordered breathing (SDB) are associated with cardiometabolic risk (CMR), but the degree of severity at which SDB affects cardiometabolic health is unknown. We assessed the relationship between the CMR and the apnea-hypopnea index (AHI), to identify a threshold of AHI from which an increase in the CMR is observed, in adolescents with obesity. We also compared the clinical, cardiometabolic and sleep characteristics between adolescents presenting a high (CMR+) and low CMR (CMR-), according to the threshold of AHI.

METHODS AND RESULTS

114 adolescents with obesity were recruited from three institutions specialized in obesity management. Sleep and SDB as assessed by polysomnography, anthropometric parameters, fat mass (FM), glucose and lipid profiles, and blood pressure (BP) were measured at admission. Continuous (MetScore_FM) and dichotomous (metabolic syndrome, MetS) CMR were determined. Associations between MetScore_FM and AHI adjusted for BMI, sex and age were assessed by multivariable analyses. Data of 82 adolescents were analyzed. Multivariable analyses enabled us to identify a threshold of AHI = 2 above which we observed a strong and significant association between CMR and AHI (Cohen's d effect-size = 0.57 [0.11; 1.02] p = 0.02). Adolescents with CMR+ exhibited higher MetScore_FM (p < 0.05), insulin resistance (p < 0.05), systolic BP (p < 0.001), sleep fragmentation (p < 0.01) and intermittent hypoxia than CMR- group (p < 0.0001). MetS was found in 90.9% of adolescents with CMR+, versus 69.4% in the CMR- group (p < 0.05).

CONCLUSIONS

The identification of a threshold of AHI ≥ 2 corresponding to the cardiometabolic alterations highlights the need for the early management of SDB and obesity in adolescents, to prevent cardiometabolic diseases.

CLINICAL TRIALS

NCT03466359, NCT02588469 and NCT01358773.

Validity of Slaughter Equations and Bioelectrical Impedance Against Dual-Energy X-Ray Absorptiometry in Children

OBJECTIVE

This study aimed to 1) analyze the criterion validity of the Slaughter equations (Slg-Eq) and bioelectrical impedance analysis (BIA) to estimate body fat percentage (BFP) and fat mass index (FMI) at different degrees of obesity in children compared with dual-energy x-ray absorptiometry (DXA) and 2) determine their agreement over time.

METHODS

Ninety-two children with overweight or obesity (10.0 [SD 1.2] years; 34.8% girls) participated in this 20-week study. Anthropometric, BIA, and DXA measurements were performed.

RESULTS

Both Slg-Eq and BIA methods underestimated BFP and FMI against DXA, and the bias was markedly larger with BIA (mean absolute percentage error = 11% for Slg-Eq vs. 18%-21% for BIA); a larger underestimation was observed in girls compared with boys for Slg-Eq (P ≤ 0.001), and the observed underestimation in adiposity was reduced as weight status increased. Systematic errors were kept constant over time, so no large differences between methods were observed in the change in adiposity.

CONCLUSIONS

At the group level, Slg-Eq provides a more valid estimation of BFP and FMI than BIA. At the individual level, Slg-Eq shows larger estimation errors. The validity of these methods might differ in sex and weight status. Nevertheless, both methods seem to be valid for monitoring changes in adiposity.