Body fat reference curves for healthy Turkish children and adolescents

First body fat reference curves for Macedonian children and adolescents: the MAKFIT study

Introduction

Introduction: childhood obesity is a worldwide chief health problem. Along with body mass index, body fat percentile values can also be used to predict future cardiovascular and metabolic health risks. Objective: the study's aim is to define the percentile values and curves about the fat tissue percentage through which the childhood and adolescent overweight/obesity in the Republic of North Macedonia will be diagnosed. Methods: the research was conducted on a sample of 15,075 children and adolescents aged six to 14 years (7,627 boys and 7,448 girls). Body fat percentage was established by bioelectrical impedance. The LMS method was used in percentile values and curves' construction. Results: the boys' 50th percentile curve shows that the body fat percentage average value has a slight growth from seven to ten years of age, but after their 10th it begins to drop continuously until the age of 14 years. At the same time, the girls' body fat percentage average value increases continuously from six to 14 years of age. Conclusion: since body mass index cannot always establish body fat content, the direct assessment of body fat by bioelectrical impedance would be of great advantage for pediatric and clinical decisions. Therefore, the study provides referent percentile norms for the body fat percentage of healthy Macedonian children and adolescents. For this purpose, a practical and clinically applicable method was used. The obtained referent percentile norms can be useful in assessing overweight and obesity in Macedonian children and adolescents.

The potential of the Mediterranean diet to improve metabolic control and body composition in youths with Type 1 Diabetes Mellitus

BACKGROUND

A chronic autoimmune disease with an increasing incidence rate, type 1 diabetes mellitus (T1DM) is typified by the degeneration of the pancreatic beta cells. Diabetes management is significantly impacted by nutrition. Although it has been demonstrated that following the Mediterranean diet (MD) improves metabolic control with type 2 diabetes in children and adults, its effects on children with T1DM have not received much attention.

OBJECTIVE

Therefore, the purpose of this study was to assess whether adherence to Mediterranean diet is associated with better metabolic control and body composition in youths with Type 1 Diabetes Mellitus. The study recruited T1DM patients aged 6-18 years at İstanbul University Cerrahpaşa Medical Faculty Hospital's Pediatric Endocrinology and Diabetes Outpatient Clinic for follow-up.

METHODS

In addition to demographic variables, some anthropometric measurements, body composition and biochemical parameters such as: Trygliceride(TG), Total cholesterol (TC), High density lipoprotein cholesterol (HDL-C), Low density lipoprotein cholesterol (LDL-C), (Aspartate aminotransferase) AST, Alanine transaminase (ALT) and glycated hemoglobin (HbA1c) was analyzed. The time in range (TIR) is a value obtained from continuous glucose monitoring. KIDMED was used to assess the participants' adherence with the MD.

RESULTS

Good adherence to the MD resulted in much larger height SDS than poor adherence. Poor adherence to MD resulted in higher body fat than moderate and good adherence. There is positivite correlation between TIR and KIDMED score. Adherence to MD is negatively associated with HbA1c. The regression anaylsis showed that a one-point rise in the KIDMED score would result in a 0.314-unit reduction in the HbA1c value (p < 0.01).

CONCLUSIONS

In conclusion, this study found that adhering to MD led to improved anthropometric measurements, biochemistry, and diabetes outcomes. Awareness among children, adolescents with T1DM, and their parents about the benefits of MD compliance for glycemic and metabolic control should be raised.

Aromatase Inhibitors May Increase the Risk of Cardiometabolic Complications in Adolescent Boys

INTRODUCTION

Aromatase inhibitors (AIs) are increasingly used in children and adolescents to augment adult height. The aim of this study was to investigate the effects AIs have on cardiac morphology, functions and their relation to several metabolic parameters in adolescent boys.

METHODS

Three groups matched for sex (boys, n = 67), age (median age 13.5 years), weight, height, body mass index, and puberty stages were enrolled: (i) Group 1: 23 patients using AIs (only AI (n = 6) or in combination with growth hormone (GH) (n = 17)) for at least 6 months; (ii) Group 2: 22 patients using only GH, and (iii) Group 3: 22 healthy boys. Two-dimensional, M-mode conventional Doppler and tissue Doppler examinations of the left ventricle (LV) were performed. Bioelectrical bioimpedance analyses was conducted and follicle-stimulating hormone, luteinizing hormone, total testosterone, lipid, and hemogram parameters were obtained.

RESULTS

Patients in Group 1 had significantly higher serum total testosterone (p < 0.001) and hemoglobin (p < 0.001) levels, fat free mass (p = 0.005), LV mass (LVM) (p = 0.002), as well as increased LV posterior wall diameter (LVPWD) (p = 0.002), interventricular septum diameter (IVSD) (p = 0.019), and myocardial systolic wave velocity (Sm) (p = 0.020) compared to the two other control groups. No significant differences were observed in terms of diastolic and systolic functions and lipid profiles (p > 0.05). There were positive correlations between total testosterone, hemoglobin levels, LVM, LVPWD and IVSD (p < 0.05).

CONCLUSION

Increased LVM, LVPWD, IVSD and Sm of patients receiving AI therapy in comparison to the control groups, and the significant correlations of these parameters with total testosterone and hemoglobin levels were determined as potential side effects of AIs. These findings emphasize the need of routine cardiac follow-up in patients using AIs.

Evaluation of the effect of obesity, dietary glycemic index and metabolic profiles on the cardiovascular risk in children with classical phenylketonuria

OBJECTIVES

To compare the glycemic index(GI),obesity,echocardiographic,and arterial stiffness measurements with the healthy control group to evaluate the cardiovascular risk of pediatric classical phenylketonuria(PKU).

METHODS

The study was a prospective observational,involving 104 pediatric volunteers between 2019 and 2020.Two groups were formed:the PKU patient group and the healthy control group.These two groups were further divided into three subgroups:obese,overweight,and normal weight.The patients' anthropometric measurements,body fat analysis,biochemical analysis, GI and glycemic load(GL),arterial stiffness measurements,and echocardiographic findings were recorded.

RESULTS

The PKU patient group's glucose,total cholesterol,LDL,and HDL values were significantly lower than the healthy control group(p = 0.010 for glucose and p = 0.001 for total cholesterol,LDL and HDL).Triglyceride levels were higher in the PKU patient group than in the healthy controls(109.6 vs. 76.7 mg/dl,p = 0.001). GI and GL were significantly lower in the PKU patient group than in the healthy control group(GI 453 vs. 392.9,p = 0.017 and GL 101.1 vs. 85.5,p = 0.036).Left ventricular mass(LVM)-z-score and LVM index were significantly higher in the PKU group than in the healthy control group(LVM z-score 0.9 vs. 0.5,p = 0.014 and LVM index 38.9 vs. 32.7 g/m2.7,p = 0.001). A moderately statistically significant positive correlation was found between the mean phenylalanine(phe) value and pulse wave velocity(PWV) among the PKU patient groups(R: 0.477,p < 0.001).A moderately statistically significant positive correlation was also found between waist circumference and PWV in the PKU patient group(R:0.541, p < 0.001).

CONCLUSIONS

Our study found that close follow-up of phe levels and PWV is more critical than obesity, GI, and GL in the cardiovascular evaluation of classical PKU patients.A large number of multicenter pediatric studies are needed in this area.

Performance of triponderal mass index, body mass index z scores, and body mass index performance in the diagnosis of obesity in children and adolescents

OBJECTIVES

Childhood obesity is a global health problem that affects millions of children and causes obesity-related adverse health outcomes in both childhood and adulthood. Although body mass index (BMI) z scores and percentiles are used in the diagnosis of obesity in children, it has been emphasized in recent years that the triponderal mass index (TMI) may be more accurate for this purpose. We aimed to compare TMI with BMI in the diagnosis of obesity in Turkish children and adolescents.

METHODS

The records of 3540 children who applied to Gülhane Training and Research Hospital were retrospectively scanned and the data of 1161 children were included in the study. The body fat percentage (BF%) was calculated by a formula, and children with body fat in the ≥95th percentile were classified as obese. Receiver study characteristics analysis was performed to compare the effectiveness of TMI and BMI in the diagnosis of obesity.

RESULTS

TMI correlated more with BF% (r = 0.863) than fat mass (r = 0.664); BMI correlated more with fat mass (r = 0.957) than BF% (r = 0.714) (P < 0.001). TMI had the highest area under the curve (AUC) in boys at diagnosis of obesity (6-11 y = 0.981; 12-15 y = 0.994). Girls ages 6 to 11 y had the same AUC for all 3 indexes (AUC = 0.977), whereas girls ages 12 to 15 y had the highest AUC for TMI (AUC = 0.967). However, the AUC values between all indices were very close.

CONCLUSIONS

TMI can be used to diagnose obesity in Turkish children and adolescents in both boys and girls similarly and with good performance. The correlation with BF% and stability of TMI makes this index more advantageous. However, it should be noted that the performance of each of the 3 indices is very close to that of the others, and adjustments should be made according to age and sex.

Body-Fat-Percentile Curves for Thai Children and Adolescents

This study aimed to generate sex-specific percentile curves for the percentage of body fat (PBF) in Thai children using a bioelectrical impedance analysis (BIA). The secondary objective of this study was to determine the association between body fat and other anthropometric measurements. A cross-sectional study was conducted on 3455 Thai school children aged 6-18 years. The body-fat contents were measured using BIA. Smoothed percentile curves of PBF were derived using a scatter plot with a smooth curve fitted by the Loess method. The correlations between the body fat and the anthropometric measurements were assessed using the Spearman's rank correlation. The 50th and lower body-fat-percentile curves of the boys slowly increased until age 12, after which they slightly decreased until age 15 and then slightly increased until age 18. In the higher boys' percentiles, the body fat sharply increased until age 11 and then decreased until age 18. In the girls, the PBF percentiles increased steadily from 6 to 18 years. The body-mass index was strongly correlated with PBF and fat mass in both sexes. The waist-to-height ratios showed strong correlations with PBF and fat mass in the boys but were moderate in the girls. The use of PBF percentile curves can be an additional metric for the evaluation of obesity in Thai children.

Triponderal mass index is as strong as body mass index in the determination of obesity and adiposity

OBJECTIVE

In determining obesity and body adiposity, triponderal mass index (TMI) is as strong an anthropometric measurement as body mass index (BMI). The aim of this study was to develop TMI reference values for Turkish children and adolescents and compare TMI with BMI according to body adiposity and obesity indices.

METHODS

Data from the DAMTCA-II (Determination of Anthropometric Measurements of Turkish Children and Adolescents II) study were used in this cross-sectional study. Data from 4330 children (1931 boys, 2399 girls) ages 6 to 17 y were evaluated, and the TMI percentile values were produced. The predictive power of TMI and BMI for obesity and overweight were done for waist circumference, waist/height ratio, body fat percentage, and upper arm fat area, which are different parameters used to determine body adiposity.

RESULTS

The 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th, and 97th TMI percentiles and mean values were calculated for all children's age and sex. TMI cutoff values were calculated by receiver operating characteristic analysis regarding waist/height ratio 0.5, waist circumference ≥90 percentile, arm fat area ≥85 percentile, and body fat percentage ≥85. TMI and BMI area under the curve values were similar for each of these four measurements. TMI was as robust an index as BMI in demonstrating obesity and adiposity for all age groups in boys and girls. It was concluded that the values >90th percentile (median 15.8 kg/m³) in girls aged ≤10 y, 95th percentile (median 16.2 kg/m³) in girls aged >10 y, >85th percentile (median 14.9 kg/m³) in boys aged ≤12 y and 75th percentile (median value 14.5 kg/m³) in boys aged >12 y are critical values for TMI when evaluating adiposity and obesity.

CONCLUSIONS

We considered that TMI is as effective as BMI in terms of waist/height ratio, waist circumference, arm fat area, and body fat percentage in determining overweight and obesity in children. The ages at which TMI showed distinct variation were determined for both sexes.

Reference percentiles for bioimpedance body composition parameters of healthy individuals: A cross-sectional study

OBJECTIVES

The aim of this study was to estimate the percentage distribution of body composition parameters for healthy people at different ages from the assessment of electrical bioimpedance.

METHODS

A cross-sectional study of healthy Brazilian aged 5 years and older. Were evaluated: total body fat; percent body fat; fat-free mass; percent lean mass; fat mass index; and fat-free mass index.

RESULTS

Of 1240 participants, with a median age of 27.0 years, 52.5% were female, and 73.7% were Caucasian. Most of the body composition variables were associated with age. The fat-free mass increased from youth to adult and decreased in the elderly in both sexes, with higher values in males than in females. In males, the percentage of lean mass has higher values in adolescence compared to childhood, and in adults compared to the elderly, when analyzed from the 50^th percentile. In women, fat-free mass compared to adulthood, values were higher in childhood and lower in older ages.

CONCLUSIONS

The study is the first to describe the Brazilian reference values for most clinical parameters of bioimpedance in percentiles stratified by different life cycles and sex. These findings can be very useful in clinical practice for health promotion and monitoring the nutritional status of the individual.

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.

Reference Data for Fat Mass and Fat-Free Mass Measured by Bioelectrical Impedance in Croatian Youth

Fat mass and fat-free mass have become useful clinical indices in determining healthy growth and physical development during critical periods of childhood and adolescence; however, despite a wide range of nutritional surveillance its study is limited by a lack of reference data. The purpose of this study was to establish sex-specific and age-specific standards for fat mass and fat-free mass in a large sample of Croatian children and adolescents. In this cross-sectional study, we collected data from 12,678 participants aged 11 to 18 years old (mean age ± standard deviation (SD): 14.17 ± 2.25 years; height 164.56 ± 11.31 cm; weight: 57.45 ± 13.73 kg; body mass index: 21.24 ± 3.67 kg/m²; 53% girls). Fat mass and fat-free mass were measured three times by bioelectrical impedance. The Lambda, Mu and Sigma methods were used to create percentile charts for fat mass index (FMI) and fat-free mass index (FFMI; fat mass and fat-free mass divided by height²). Sex and age differences were calculated using an analysis of variance (ANOVA) with post hoc comparisons. Boys had lower FMI (from 2.66 to 3.89) and higher FFMI values (from 16.90 to 17.80) in all age groups, compared to girls (for FMI from 2.79 to 5.17 and for FFMI from 14.50 to 14.90, p < 0.001). In boys, FMI slightly declined until the age of 14, after which an increase from the age of 15 to 18 was observed. In girls, FMI gradually increased from the age of 11 to 18 (p < 0.001). In general, FFMI increased by age in boys [F(7,5440) = 52.674, p < 0.001], while girls had more stable FFMI across all age groups [F(7,7222) = 2.728, p = 0.057]. The newly established sex-specific and age-specific reference data could be used for national surveillance and to screen for children and adolescents with high FMI and low FFMI.

Body Fat Mass, Percent Body Fat, Fat-Free Mass, and Skeletal Muscle Mass Reference Curves for Czech Children Aged 6-11 Years

Background: Negative lifestyle trends are reflected in overweight and obese children, in which their lack of physical activity results in decreased muscle mass. This study aimed to define age- and sex-specific reference curves for body fat mass (BFM), skeletal muscle mass (SMM), fat-free mass (FFM), and percent body fat (%BF) in Czech children. Methods: Body composition was measured by segmental bioelectrical impedance (BIA, InBody 720). The research sample included 2093 children aged 6–11 years (1008 boys and 1085 girls). Only children whose parents provided informed consent were included. Statistical analysis was performed using SPSS v. 22. The statistical analysis was performed separately by age and sex. Anthropometric data were summarized as means and standard deviation. The percentile curves (P3, P10, P25, P50, P75, P90, and P97) of BFM, FFM, %BF, and SMM were calculated using the gamlss package in R 3.4.2 (R Foundation for Statistical Computing, Vienna, Austria). Results: This study developed age- and gender-specific percentile curves of SMM, FFM, BFM, and %BF for Czech children aged 6–11 years. During childhood, BFM and %BF increased in boys, peaking at approximately 11 years of age. Girls displayed a different pattern of age-related changes in BFM and %BF compared to that in boys. These parameters gradually increased during childhood. This pattern was also observed for SMM and FFM in both sexes. Conclusions: The purpose of this study was to serve as a reference to improve methods to evaluate body composition in Czech children and for comparison with studies worldwide.

Physical Fitness in Young Padel Players: A Cross-Sectional Study

This study aimed to examine the fitness characteristics and to identify the influence of gender and practice experience between young amateur padel players. A total of thirty-four padel players (n = 19 boys and 15 girls) aged 13 to 17 years old (age 14.6 ± 1.5 years; body mass 63.4 ± 14.5 kg; height 166.6 ± 9.8 cm; 6.2 ± 2.5 padel experience) volunteered to participate. Body composition was assessed by bioimpedance. Change of direction and agility were evaluated by two padel-adapted tests. Upper-limb strength measurement included overhead and side medicine ball throws with dominant and non-dominant hands. One-way ANCOVA was used to determine whether there were significant differences between gender and experience on fitness variables adjusting for age as a covariate. Male and female young padel players presented an apparently healthy body composition and exhibited similar performance in all fitness tests except for jumping ability. Practice experience seemed to influence upper-limb throwing strength, however, sub-analyses revealed no conclusive results. These results contribute to the existing knowledge in padel by providing new data about the fitness status of amateur young players aged 13 to 17 years old and open a window for future interventions using padel as a health promotion tool among youths.

Association between relative fat mass, uric acid, and insulin resistance in children with chronic kidney disease

INTRODUCTION

This cross-sectional study investigates the association between insulin resistance (IR) and serum uric acid (sUA) and relative fat (RFM) and lean mass (RLM) profiles in children with chronic kidney disease (CKD).

MATERIAL AND METHODS

RLM and RFM were assessed by bioimpedance spectroscopy in 41 children and adolescents. Normal weight obesity (NWO) was defined as normal height-age body mass index and RFM >85th percentile, according to age and sex. Homeostatic model assessment of insulin resistance (HOMA-IR) level >95th percentile, according to sex and pubertal stage, and sUA >7 mg/dl were used to define IR and hyperuricemia, respectively.

RESULTS

High RFM (15 patients) and NWO (7 patients) were associated with higher HOMA-IR in total (p < 0.001) and normal-weight patients (p = 0.004), respectively. RFM was positively and RLM negatively correlated to HOMA-IR (rs = 0.500, p = 0.001 and rs = -0.539, p < 0.001, respectively) and sUA (rs = 0.370, p = 0.017 and rs = -0.325, p = 0.038, respectively), while sUA was positively correlated to HOMA-IR (rs = 0.337, p = 0.031). Hyperuricemia (16 patients) was positively associated with higher RFM and HOMA-IR (p = 0.001 and p = 0.010, respectively). The correlation between sUA and HOMA-IR lost significance after adjustment for RFM. In logistic regression analysis, a 5% increase in RFM was associated with IR (11 patients) independently of the age, sex, sUA, and CKD stage in both total (OR 2.174, 95% CI 1.115-4.225) and normal-weight (OR 3.504, 95% CI 1.110-11.123) patients.

CONCLUSION

Children with high RFM, including those presenting NWO, are at risk for IR regardless of CKD stage. RFM is probably the mediator of the link between sUA and IR.

The relationship between body fat ratio and blood pressure in school-age children

Hypertension (HTN) and obesity prevalences are rising in childhood and it is important to evaluate associations of these situations. The objective of this study is to investigate the relationship between HTN and body fat ratios (BFR) in children. This cross-sectional study was conducted among 134 participants who were directed to pediatric nephrology outpatient clinic with the prediagnosis of primary HTN. Weight, height, body fat ratio, blood pressure, and ambulatory blood pressure monitor (ABPM) was carried out for all the participants. Of the participants, 70 of them were diagnosed as hypertension with ABPM and included in the patient group, 64 of them had elevated office blood pressure (BP) but normotensive according to ABPM were included in the control group. Body fat ratio (BFR) levels of the patient group were higher than the control group (p < 0.05). There were significant linear correlation between night systolic blood pressure (SBP), night diastolic blood pressure (DBP), night mean arterial pressure (MAP), and BFR in the patient group (p < 0.05). There was a negative correlation between BFR and dipper (p = 0.022; p < 0.05) in the patient group. There was no correlation between BFR and blood pressures or dipper in the control group. According to our results BFR levels have significant association with HTN. According to our findings high BFR especially effects night BP, pulses, nondipping, and nighttime values can be evaluated only with ABPM. For prevention of HTN in children, caution should be given to monitor and lower BFR values.

Fat and fat-free mass index references in children and young adults: assessments along racial and ethnic lines

BACKGROUND

Fat-free mass index (FFMI) and fat mass index (FMI) are superior to BMI and fat percentage in evaluating nutritional status. However, existing references fail to account for racial/ethnic differences in body composition among children.

OBJECTIVES

Our goal was to produce age-based normative references for FFMI and FMI in children for specific racial/ethnic groups.

METHODS

Body composition, weight, and height were measured in 1122 normal healthy children aged 2-21 y. Bone mineral content measured by DXA, total body water by deuterium dilution, and total body potassium by whole-body γ counting were combined to calculate fat-free mass (FFM) and fat mass (FM) using equations based on the Reference Child and Adolescent models. FFMI and FMI were calculated by dividing FFM and FM by height squared, respectively. After outlier removal, the LMS (Lambda-Mu-Sigma) function within R's GAMLSS package was used to produce age-based FFMI and FMI growth curves for black (B), white (W), and Hispanic (H) children for each sex. Combined models were produced in cases where outcomes did not differ by race/ethnicity. Resulting models were compared with previously published FFMI and FMI models.

RESULTS

FFMI and FMI models based on 1079 children, aged 2-21 y, were created for both sexes. FFMI models for B children showed higher values throughout. W and H children were combined to produce FFMI models for each sex. H boys were modeled individually for FMI, whereas W and B boys were combined. FMI models for girls were created for each race/ethnicity. Models agreed well with those based on children from the United Kingdom of comparable race/ethnicity.

CONCLUSIONS

Race/ethnicity-specific references for FFMI and FMI will increase the accuracy of health and nutrition status assessment in children over race/ethnicity-generic references. The models allow the calculation of SD scores to assess health and nutrition status in children.

Association between pubertal development stages and body adiposity in children and adolescents

Background

The study aimed to analyze the association between pubertal development stages and adiposity in children and adolescents.

Methods

Cross-sectional study conducted in 2007 in Florianópolis, Brazil, with 2339 schoolchildren 32 aged 8 to 14 years old (1107 males). The outcome (adiposity) was evaluated using Z score and 33 percentilee values > = 85 of four skinfolds (triceps, subscapular, suprailiac and calf) and waist 34 circumference. Total body adiposity (Z score of the sum of skinfolds), central adiposity (Z score 35 of waist circumference) and peripheral adiposity (Z scores of triceps and calf skinfolds) were 36 estimated. Pubertal development stages was self-assessed according to Tanner stages of development. Thirty-seven Children and adolescents were classified according to tertiles of age for each pubertal development stages 38 stage - early, normal and late. Statistical analysis was performed using univariate and 39 multivariate Poisson regression models.

Results

Children and adolescent from both sexes with early pubertal development stages presented higher prevalence of central adiposity (waist circumference), with adjusted prevalence ratio (CI 95%) of 2.21 (1.12; 4.35) for males and 2.18 (1.04; 4.57) for females (reference group: normal pubertal development stages). Among females, there was a reduction in the prevalence of excess adiposity with decreased occurrence of early pubertal development stages. There was a strong relationship between adiposity and pubertal development stages.

Conclusions

Excess adiposity was higher in both sexes for those with early pubertal development stages.

Comparison of bioimpedance body composition in young adults in the Russian Children's Study

BACKGROUND & AIMS

Body mass index is a simple anthropometric measure (kg/m²) used as an indirect estimate of body fat in individuals, and in assessments of population health and comparisons between populations. Bioelectrical impedance analysis (BIA) is often used to provide additional information on body fat and fat-free mass, and has been used to generate body composition reference data in national health surveys. However, BIA measurements are known to be device-specific and there are few published studies comparing results from different BIA instruments. Therefore, we compared the performance of two BIA instruments in the Russian Children's Study (RCS) of male growth, pubertal development and maturation.

METHODS

Paired BIA measurements were obtained using the Tanita BC-418MA (Tanita Corp., Tokyo, Japan) and ABC-01 'Medas' (Medas Ltd, Moscow, Russia) BIA instruments. Cross-sectional data on 236 RCS subjects aged 18-22 years were used for the BIA comparison and the development of a conversion formula between measured resistances; follow-up data (n = 96) were used for validation of the conversion formula.

RESULTS

Whole-body resistances were highly correlated (Spearman rho = 0.95), but fat mass (FM) estimates were significantly higher with the Medas than the Tanita device (median difference 3.3 kg, 95% CI: 2.9, 3.6 kg) with large limits of agreement (LoA) for the FM difference (-2.0, 8.6 kg). A conversion formula between the resistances (Res) was obtained: Medas Res = 0.882 × Tanita Res+26.2 (r² = 0.91, SEE = 17.6 Ohm). After applying the conversion formula to Tanita data and application of the Medas assessment algorithm, the 'converted' Tanita FM estimates closely matched the Medas original estimates (median difference -0.1 kg, 95% CI: -0.3, 0.2 kg), with relatively small LoA for the FM difference (-2.3 to 2.1 kg), suggesting potential interchangeability of the ABC-01 'Medas' and Tanita BC-418MA data at the group level.

CONCLUSIONS

Our results support the importance of cross-calibration of BIA instruments for population comparisons and proper data interpretation in clinical and epidemiological studies.

The Relationship between the Waist Circumference and Increased Carotid Intima Thickness in Obese Children

Background: This study aimed to evaluate the cardiometabolic risk factors in normotensive obese and hypertensive obese (HT-obese) children by comparison of anthropomorphic measurements, fat distribution, carotid artery intima-media thickness (CIMT), and inflammatory markers. Methods: Fifty-three obese patients 10-18 years of age with a BMI-for-age/gender >95th percentile and 20 age- and gender-matched healthy volunteers enrolled in the study. Obese patients were divided into two groups according to the presence of hypertension (HT), as follows: HT-obese subgroup (n = 30) and nonhypertensive obese (non-HT-obese) subgroup (n = 23). Results: Weight standard deviation score (SDS), BMI-SDS, waist circumference (WC) SDS, and the fat tissue z-score were significantly higher (p < 0.001 for all) in the obese patients than the control groups. Obese patients had higher 24-hour systolic blood pressure (SBP) SDS and leptin, high-sensitivity C-reactive protein, tumor necrosis factor-alpha, and interleukin-6 levels. Furthermore, CIMT and CIMT-SDS were significantly higher in them. HT-obese patients (n = 30) had significantly higher WC-SDS and lower serum leptin and adiponectin levels than those of non-HT-obese group (n = 23). Finally, an association between increased CIMT-SDS and WC-SDS (β = 0.399, p = 0.002) and 24-hour SBP-SDS (β = 0.272, p = 0.009) was shown. Conclusions: Association between increased WC and HT implies the importance of central obesity in atherosclerosis. We concluded that WC measurement could be used to define risk groups since it is related to cardiometabolic complications.

Body composition reference charts for UK infants and children aged 6 weeks to 5 years based on measurement of total body water by isotope dilution

Background

Until recently, pediatric body composition reference data were very limited, hindering interpretation of measurements. In the last decade, such data emerged for several techniques for children ≥ 5 years, but equivalent data for younger age groups remain lacking, due to their poor compliance with most techniques.

Objectives

To provide reference data for use in clinical practice and research from 6 weeks to 5 years, that are based on measurements of total body water (TBW) by isotope dilution.

Design

The data on anthropometry and TBW were available from studies of 463 infants and children aged 6 weeks to 7 years, conducted between 1988 and 2010. Both breast-fed and formula-fed infants were included. TBW was measured by ²H- or ¹⁸O-labeled water, and converted to fat-free mass (FFM) using published hydration coefficients. Reference charts and SD scores (SDS) were constructed for FFM, fat mass (FM), FFM index and FM index for each sex, using the lambda-mu-sigma method.

Results

Both sexes were significantly heavier and longer than UK 1990 reference data (p < 0.01), but did not differ in body mass index SDS. Breast-fed infants were longer than formula-fed infants but did not differ in body composition.

Conclusions

These reference data will enhance the ability of clinicians to assess and monitor body composition and FFM/FM accretion in clinical practice in younger age groups. Total body water can be measured in most patients, though abnormalities of hydration must be addressed. However, the centiles do not overlap exactly with those published for older age groups, limiting comparability between younger and older children.

Representative body composition percentiles from bioelectrical impedance analyses among children and adolescents. The MoMo study

BACKGROUND & AIMS

With high prevalence of overweight and obesity in developed countries, the assessment of body composition in children and adolescents is of growing interest. The aim of this study was (i) to provide up-to-date population wide percentiles for meaningful diagnostic bioelectrical impedance outcome parameters and (ii) to specify reference values for these measures in a normal weight subpopulation.

METHODS

A representative nationwide sample of 4 to 24-year-old children and adolescents (n = 3593) was drawn out of 167 primary sample points across Germany from 2009 to 2012 (Motorik-Modul study wave 1). Fat free mass index (FFMI), fat mass index (FMI), body cell mass index (BCMI) and phase angle (PA) were derived from four electrodes 50 kHz bioelectrical impedance analyses. Sex-specific percentiles were calculated using the LMS-method for the total study population and a normal weight subsample (defined according to the international BMI-standard by Cole).

RESULTS

Percentile curves for body composition parameters are similar between boys and girls until puberty. Subsequently, girls show a higher FMI than boys, and boys increase their FFM, BCM, and PA time-shifted, in that order. Differences in FMI between the overall and the normal weight sample increase with age, showing an age-dependent prevalence for overweight and obesity among the representative German sample.

CONCLUSIONS

Results from the normal weight sample can be used as reference values to define a healthy body composition. Differences in body composition between the representative German sample and the normal weight subsample reveal a high prevalence of elevated fat mass in the population of children and adolescents living in Germany.

Long-term changes in fat distribution in children and adolescents aged 3-18 from Krakow (Poland), within the last 30 years (from 1983 to 2010)

In Poland, even in the late twentieth century, the problem of obesity was not significant. However, recent studies have shown an increase in the prevalence of overweight and obesity. Socioeconomic changes, in last decades, approached Poland to Western Europe. A lifestyle of Poles (physical activity and diet) have changed radically. The aim of the study was to investigate changes in adiposity in children and adolescents over the last decades. Two cross-sectional studies were made in 1983 and 2010. The analysis included 10,324 children and adolescents aged 3-18 living in Krakow (Poland). Data on selected skinfolds (triceps, subscapular, abdominal, suprailiac, calf) were collected and compared between the series of studies. The total body fat (sum of 5 skinfolds) was higher in contemporary boys. In girls, there were not noticed such changes. In both sexes, the adiposity of triceps and supscapular region decreased. In the case of abdominal skinfold - there were no significant changes in boys, while contemporary girls had a smaller abdominal adiposity. In boys, there were noticed reduction in suprailiac skinfold thickness. In the case of girls, the reverse trend was reported - contemporary girls were characterized by higher suprailiac adiposity. Children studied in 2010 were characterized by greater calf skinfold. Changes in adiposity are worrying, especially in boys. The priority should therefore be effective prevention and intervention programs. They can prevent further deepening of the problem among Polish children, by the time it will be as severe as in Western Europe.

Growth and development in school-age children from Rostov region, Russia: Comparison between urban and rural settings

The purposes of the current study were: (1) to describe growth and physical development and establish norms for schoolchildren from Rostov region in Russia; (2) to compare major characteristics of development between urban and rural children by sex and age. Nearly 200,000 children (198,712) aged between 7 and 17 years from 232 urban and rural schools of Rostov region (Southern Federal District of Russia) participated in the study. School age is a period of intensive growth and physiological and psychological development. Irregularities of personal development are caused by a multitude of factors, such as sex differences, heredity, socio-economic status of a family, standard of living, particular environmental conditions, and lifestyle. It has been established that children from the Southern Federal District of Russia had body mass index values higher than age-appropriate norms for all Russians (Total Russian, Rudnev et al., 2014) and World Health Organization charts. Children from urban settings were taller and heavier than children from rural settings. Sex is one of the most influential factors which play key role in determining specific characteristics of growth and personal development. According to our results, boys and girls both had similar age-related changes in weight and height, but their respective dynamics differed. Girls' height and weight values accelerated at the age 10 to 12 years and plateaued after the age fourteen, whereas in boys height and weight steadily increased with age, showing slight acceleration at the age 12 to 13 years, and reached a plateau by the age of seventeen.

Changes in inflammatory markers in estonian pubertal boys with different BMI values and increments: A 3-Year Follow-Up Study

OBJECTIVE

Serum inflammatory markers could help to identify those boys with overweight (OWB) who gain weight more extensively during puberty. This study aimed to examine the longitudinal changes in different serum inflammatory markers through puberty in boys with different BMI values and increments.

METHODS

Twenty-six OWB and 29 normal-weight boys (NWB) were followed yearly for 3 years to measure changes in BMI and serum concentrations of 12 inflammatory markers.

RESULTS

OWB had higher (P < 0.033) baseline interleukin (IL)-6, IL-8, interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-1α concentrations in comparison with NWB. Over the 3-year period, IFN-γ (P = 0.0001) and TNF-α (P = 0.0042) decreased more in OWB compared to NWB. Serum IL-8, monocyte chemoattractant protein (MCP)-1, and leptin increased further in those OWB who gained BMI more extensively through puberty compared to OWB who gained weight at slower rates (P < 0.033).

CONCLUSIONS

Serum IFN-γ and TNF-α levels decreased more during pubertal years in OWB compared to NWB, indicating that pubertal maturation itself may have a favorable impact on the inflammation of obesity. Serum IL-8, MCP-1, and leptin could help to identify OWB who gain BMI more extensively during pubertal years.

Endoglin and obestatin levels, cardiometabolic risk factors and subclinical atherosclerosis in children aged 10-18 years

BACKGROUND

The aim of this study was to investigate the early signs of atherosclerosis and to evaluate serum endoglin and obestatin levels as predictors of subclinical atherosclerosis in obese children.

METHODS

A total of 95 children (60 obese and 35 controls) aged 10-18 years were included in the study. Their endoglin and obestatin levels and biochemical parameters were measured. The carotid intima media thickness (cIMT) and brachial artery flow-mediated dilatation (FMD) responses were evaluated.

RESULTS

The cIMT values were higher (p < 0.001) and FMD responses were lower (p = 0.003) in the obese group than in the control group. A logistic regression multivariate analysis revealed that cIMT was independently associated with the body mass index (BMI) Z-score (β = 0.323, p = 0.003) and low density lipoprotein (LDL) (β = 0.29, p = 0.008), while FMD % was independently associated with waist circumference (β = -0.36, p = 0.002). The obese and control groups were similar in endoglin (p = 0.67) and obestatin levels (p = 0.70). The endoglin level was inversely correlated with the cholesterol and LDL levels (r = -0.23, p = 0.032; rho = -0.25, p = 0.019).

CONCLUSIONS

The cIMT and brachial artery FMD response in obese children are significantly different compared to healthy controls. Circulating endoglin and obestatin levels are not predictive markers for subclinical atherosclerosis in obese children aged 10-18 years old.

Gender Difference in Body Fat for Healthy Chinese Children and Adolescents

BACKGROUND

This study aimed to establish gender-related differences and the percentile curves for total body fat mass percentage (Total FM%), trunk/appendicular fat mass ratio (TrAppFMR), and fat mass ratio as % fat trunk/% fat lower limb (TrLLFMR) in Chinese children and adolescents using dual-energy X-ray absorptiometry (DXA).

METHODS

Children (n = 1541; 764 girls) and adolescents aged 5 to 19 years were recruited from southern China. Total FM% and regional FM were measured by DXA. TrAppFMR values were calculated as trunk FM divided by appendicular FM, and TrLLFMR values were calculated as the ratio between the percentage of trunk FM and the percentage of lower limb FM.

RESULTS

Total FM% peaks for boys were at approximately age 11 years and continued to increase for girls throughout adolescence. Median Total FM% at the age of 19 years was 15.53% and 28.06% for boys and girls, respectively. Median TrAppFMR and TrLLFMR increases were 61% and 81% from 5 to 19 years of age in boys compared with those in girls, 31% and 54%. The curves for median TrAppFMR and TrLLFMR in girls were relatively flat, with TrAppFMR and TrLLFMR remaining near 1.0 after 16 years of age, whereas in boys, median TrAppFMR and TrLLFMR increased with age until approximately 19 years.

CONCLUSIONS

Gender differences in the patterns of proportion and distribution of body fat were found. We present sex-specific percentile curves for Total FM%-age, TrAppFMR-age, and TrLLFMR-age relationships in this population.

The utility of bioimpedance analysis for monitoring the children with nutcracker syndrome

We aimed to evaluate anthropometric and bioimpedance analysis (BIA) indices of children with nutcracker syndrome (NCS). Eighteen patients and 20 age-gender matched controls were enrolled. Weight, height, body mass index (BMI), mid-arm circumference (MAC), waist circumference (WC), waist/hip ratio measurements, and BIA results were assessed. Laboratory parameters and Doppler sonographic findings were recorded. The weight, BMI, MAC, WC, body fat z scores, and waist/hip ratio were significantly lower in patients than in controls (p < 0.05). Serum creatinine (Scr), albumin, HDL cholesterol, and urine protein (Up) were significantly increased in NCS patients compared to controls (p < 0.05). On multivariate analysis, body fat z score was independently related to Up and the degree of superior mesenteric artery (SMA) angle (beta = -0.965, p = 0.018 and beta = 0.841, p = 0.04, respectively).

CONCLUSION

NCS might be considered in slim proteinuric patients with unproven etiology. Serial anthropometric measurements and BIA analysis would estimate the severity of entrapment in LRV. Long-term follow-up of Scr might be required in NCS.

WHAT IS KNOWN

• Nutcracker syndrome (NCS) is very rare and characterized by the compression of LRV between aorta and SMA. What is new: • Patients with NCS have a slimmer body feature with lower anthropometric and BIA indices. • Fat percentage indicates the degree of LRV entrapment and amount of proteinuria in NCS.

Body mass index and body composition scaling to height in children and adolescent

Childhood obesity prevalence has been increased and known to be related to various diseases and mortality in adult and body mass index (BMI) has been widely used as a screening tool in children with obesity. It is important to understand what BMI is and its limitations. BMI is a measure of weight adjusted for height. Weight scales to height with a power of about 2, is the basis of BMI (weight/height(2)) as the scaling of body weight to height across adults provides powers rounded to 2. BMI has the advantage of a simple and noninvasive surrogate measure of body fat, but it has limitation in differentiating body fat from lean (fat free) mass and low-moderate sensitivity is problematic for clinical applications. Among overweight children higher BMI levels can be a result of increased either fat or fat-free mass. BMI could be divided into fat-free mass index and fat mass index. Monitoring of the changes in body composition is important as distinguishing changes in each component occur with rapid growth in adolescents as it is occur in concert with changes in the hormonal environment. Reference values for each body composition indexes and chart created with selected percentiles of a normal adolescent population could be helpful in growth assessment and health risk evaluation.

Reference curves of the body fat index in adolescents and their association with anthropometric variables

OBJECTIVES

To develop reference curves for the body fat index (BFI) in the pediatric population, in adolescents from the city of São Paulo, Brazil, and verify their association with body mass index and body fat percentage.

METHODS

The study is part of the research project "Nutritional Profile of Adolescents from Public and Private Schools of São Paulo" that was performed in 2004-2005. A total of 4,686 adolescents (2,130 boys and 2,556 girls) aged 10-15 years were divided into two groups: 10-12 and 13-15 years of age. Body mass, height, body mass index, hip circumference, body fat percentage, body fat index, and sexual maturation performed by the self-assessment method (prepubertal, pubertal, and postpubertal) were analyzed. ANOVA was performed, as well as percentile distribution, Pearson's correlation, and Bland-Altman plot.

RESULTS

In boys, there was an increase in body mass, height, body mass index, and hip circumference with advancing age and Tanner stage. In girls, there was an increase in body fat index and body fat percentage with advancing age and stage of sexual maturation. An association was found between body fat index and body mass index (r = 0.67 in boys and 0.80 in girls, p < 0.001) and body fat percentage (r = 0.71 in boys and 0.68 in girls, p<0.001).

CONCLUSION

The body fat index seems to reflect well the phenomena of sexual dimorphism in adolescence, is easy to perform, and represents a method that should be used in population samples.

Reference values of body composition indices: the Korean National Health and Nutrition Examination Surveys

PURPOSE

An increase in the prevalence of obesity has been observed in children and adolescents. As remarkable changes in body composition occur with growth during the adolescent period, it is important that changes in body composition be monitored. The purpose of this study was to propose reference percentile values for body composition indices including body mass index (BMI) in children and adolescents in Korea.

MATERIALS AND METHODS

This study was performed using data from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys. Body composition data were obtained using dual-energy X-ray absorptiometry. The percentile curves of body composition indices were constructed by the LMS method.

RESULTS

A total of 2123 children and adolescents between the ages of 10 and 19 years were included in this study. We obtained the percentile curves for BMI and body composition indices.

CONCLUSION

The reference values for body composition from this study could help with assessing body composition in Korean adolescents.

Skeletal muscle mass reference curves for children and adolescents

BACKGROUND

Skeletal muscle is key to motor development and represents a major metabolic end organ that aids glycaemic regulation.

OBJECTIVES

To create gender-specific reference curves for fat-free mass (FFM) and appendicular (limb) skeletal muscle mass (SMMa) in children and adolescents. To examine the muscle-to-fat ratio in relation to body mass index (BMI) for age and gender.

METHODS

Body composition was measured by segmental bioelectrical impedance (BIA, Tanita BC418) in 1985 Caucasian children aged 5-18.8 years. Skeletal muscle mass data from the four limbs were used to derive smoothed centile curves and the muscle-to-fat ratio.

RESULTS

The centile curves illustrate the developmental patterns of %FFM and SMMa. While the %FFM curves differ markedly between boys and girls, the SMMa (kg), %SMMa and %SMMa/FFM show some similarities in shape and variance, together with some gender-specific characteristics. Existing BMI curves do not reveal these gender differences. Muscle-to-fat ratio showed a very wide range with means differing between boys and girls and across fifths of BMI z-score.

CONCLUSIONS

BIA assessment of %FFM and SMMa represents a significant advance in nutritional assessment since these body composition components are associated with metabolic health. Muscle-to-fat ratio has the potential to provide a better index of future metabolic health.

Validation of a BMI cut-off point to predict an adverse cardiometabolic profile with adiposity measurements by dual-energy X-ray absorptiometry in Guatemalan children

OBJECTIVE

To identify a body fat percentage (%BF) threshold related to an adverse cardiometabolic profile and its surrogate BMI cut-off point.

DESIGN

Cross-sectional study.

SETTING

Two public schools in poor urban areas on the outskirts of Guatemala City.

SUBJECTS

A convenience sample of ninety-three healthy, prepubertal, Ladino children (aged 7-12 years).

RESULTS

Spearman correlations of cardiometabolic parameters were higher with %BF than with BMI-for-age Z-score. BMI-for-age Z-score and %BF were highly correlated (r=0·84). The %BF threshold that maximized sensitivity and specificity for predicting an adverse cardiometabolic profile (elevated homeostasis model assessment-insulin resistance index and/or total cholesterol:HDL-cholesterol ratio) according to receiver operating characteristic curve analysis was 36 %. The BMI-for-age Z-score cut-off point that maximized the prediction of BF ≥ 36 % by the same procedure was 1·5. The area under the curve (AUC) for %BF and for BMI data showed excellent accuracy to predict an adverse cardiometabolic profile (AUC 0·93 (sd 0·04)) and excess adiposity (AUC 0·95 (sd 0·02)).

CONCLUSIONS

Since BMI standards have limitations in screening for adiposity, specific cut-off points based on ethnic-/sex- and age-specific %BF thresholds are needed to better predict an adverse cardiometabolic profile.

Toward body composition reference data for infants, children, and adolescents

Growth charts for weight and height have provided the basis for assessment of children's nutritional status for over half a century, with charts for body mass index (BMI) introduced in the 1990s. However, BMI does not provide information on the proportions of fat and lean mass; and within the past decade, growth charts for children's body composition have been produced by using techniques such as skinfold thicknesses, body circumferences, bioelectrical impedance analysis (BIA), and dual-energy X-ray absorptiometry (DXA). For public health research, BIA and skinfold thicknesses show negligible average bias but have wider limits of agreement than specialized techniques. For patients, DXA is the best individual method, but multicomponent models remain ideal because they address perturbations in lean mass composition. Data can be expressed in age- and sex-specific SD scores, in some cases adjusting for height. Most such reference data derive from high-income countries, but techniques such as air-displacement plethysmography allow infant body composition growth charts to be developed in low- and middle-income settings, where the data may improve understanding of the effects of low birth weight, wasting, and stunting on body composition. Recent studies suggest that between-population variability in body composition may derive in part from genetic factors, suggesting a universal human body composition reference may not be viable. Body composition growth charts may be extended into adult life to evaluate changes in fat and lean mass through the entire life course. These reference data will improve the understanding of the association between growth, body composition, health, and disease.

Body fat throughout childhood in 2647 healthy Danish children: agreement of BMI, waist circumference, skinfolds with dual X-ray absorptiometry

BACKGROUND/OBJECTIVES

Total body fat percentage (%BF) evaluated by dual energy X-ray absorptiometry (DXA) scans (DXA %BF) is widely recognized as a precise measure of fatness. We aimed to establish national reference curves for DXA %BF, %BF calculated from skinfolds (SF %BF) and waist circumference (WC) in healthy children, and to compare agreement between the different methods.

SUBJECTS/METHODS

Based on 11 481 physical examinations (anthropometry) and 1200 DXA scans from a longitudinal cohort of Danish children (n=2647), we established reference curves (LMS-method) for SF %BF, WC (birth to 14 years) and DXA %BF (8-14 years). Age- and sex-specific Z-scores for body mass index (BMI), WC and SF %BF were compared. Sensitivity and specificity were calculated for agreement of WC, SF %BF and BMI with DXA %BF to identify obese children (>+1 s.d.).

RESULTS

%BF differed with age, sex, pubertal stage and social class. SF %BF correlated strongly with DXA %BF (r=0.86). BMI and WC also correlated positively with DXA %BF (Z-scores; r= 0.78 and 0.69). Sensitivity and specificity were 79.5 and 93.8 for SF %BF, 75.9 and 90.3 for BMI and 59.2 and 95.4 for WC.

CONCLUSIONS

SF %BF showed the highest correlation and best agreement with DXA %BF in identifying children with excess fat (+1 s.d.).

Measuring growth and obesity across childhood and adolescence

The dramatic rise in childhood obesity has driven the demand for tools better able to assess and define obesity and risk for related co-morbidities. In addition, the early life origins of non-communicable diseases including type 2 diabetes are associated with subtle alterations in growth and body composition, including total and regional body fatness, limb/trunk length and skeletal muscle mass (SMM). Consequently improved tools based on national reference data, which capture these body components must be developed as the limitations of BMI as a measure of overweight and obesity and associated cardiometabolic risk are now recognised. Furthermore, waist circumference as a measure of abdominal fatness in children is now endorsed by the International Diabetes Federation and National Institute for Clinical and Health Excellence for diagnostic and monitoring purposes. The present paper aims to review the research on growth-related variations in body composition and proportions, together with how national references for percentage body fat, SMM and leg/trunk length have been developed. Where collection of these measures is not possible, alternative proxy measures including thigh and hip circumferences are suggested. Finally, body ratios including the waist:height and muscle:fat ratios are highlighted as potential measures of cardiometabolic disease risk. In conclusion, a collection of national references for individual body measures have been produced against which children and youths can be assessed. Collectively, they have the capacity to build a better picture of an individual's phenotype, which represents their risk for cardiometabolic disease beyond that of the capability of BMI.

Malnutrition and its association with inflammation and vascular disease in children on maintenance dialysis

BACKGROUND

Malnutrition is associated with both inflammation and atherosclerotic cardiovascular disease in adults with chronic kidney disease. We studied the prevalence of malnutrition and its possible associations with inflammation and vascular disease in children on chronic dialysis.

METHODS

Thirty-three patients on maintenance dialysis (18 peritoneal dialysis, 15 hemodialysis) and 19 age- and gender- matched healthy controls were studied. Nutritional status was assessed by anthropometric measurements including body mass index (BMI), upper arm measurements, multifrequency bioimpedance analysis (BIA) and serum levels of albumin, prealbumin, and cholesterol. Inflammation was assessed by serum levels of C-reactive protein (CRP), interleukin (IL)-6, and tumor necrosis factor (TNF)-alpha. The carotid artery intima thickness (cIMT) was measured to assess vascular disease.

RESULTS

Compared with healthy children, patients had lower anthropometric measurements (P < 0.05) and serum albumin level (P < 0.001), and higher CRP and TNF-alpha (P = 0.030 and P = 0.007, respectively), and higher cIMT-SDS (P < 0.001). Malnutrition was present in 8 (24%) and lower BIA-based fat mass was independently associated with higher IL-6 levels (P = 0.035). An increased cIMT was present in 16 (48.5%); however, there was no difference in cIMT-SDS between patients with and without malnutrition. Carotid IMT did not show any association with nutritional indices; but positively correlated with serum IL-6 (P = 0.037), CRP (P = 0.012), and iPTH (P = 0.009), and independently associated with only iPTH (P = 0.018).

CONCLUSIONS

Children on dialysis are at an increased risk of malnutrition, inflammation, and vascular disease. Although each of these three conditions exists, there is no interaction among them all. We postulate that the malnutrition-inflammation-atherosclerosis (MIA) complex might not exist in pediatric dialysis patients.

Body fat percentiles of Brazilian adolescents according to age and sexual maturation: a cross-sectional study

BACKGROUND

The objective of this study was to determine body fat percentiles of adolescents in the city of São Paulo, Brazil, according to gender, age, and sexual maturation.

METHODS

This study involved 4,690 adolescents aged 10-15 years across 31 schools in the city of São Paulo. Sexual maturation was assessed in terms of Tanner stage. The body fat percentage was calculated using skinfold thickness. Percentile curves were calculated using the LMS (curve, mean, and coefficient of variation) method.

RESULTS

The mean body fat percentages were lower in boys aged 10-12 and 13-15 years than in girls. Body fat percentages decreased progressively with sexual maturation in boys, but increased in girls. The 85th, 95th, and 97th percentiles represent the cutoff points for moderately elevated, elevated, and very elevated body fat percentages, respectively, in pre-pubescent boys (85th, 95th, and 97th percentiles: 32.54, 95 41.04, and 97, respectively) and pubescent boys (31.09, 36.30, and 44.33, respectively). These cutoff points were lower in pre-pubescent girls (29.52, 35.01, and 41.82, respectively) and in the 97th percentile in pubescent girls (31.55, 36.20, and 41.86, respectively).

CONCLUSION

To our knowledge, these are the first body fat percentages cutoff points according to sexual maturation for adolescents aged 10-15 years in Brazil. Our results provide a significant contribution to the assessment of body composition in this population.

Use of fat mass and fat free mass standard deviation scores obtained using simple measurement methods in healthy children and patients: comparison with the reference 4-component model

Background

Clinical application of body composition (BC) measurements for individual children has been limited by lack of appropriate reference data.

Objectives

(1) To compare fat mass (FM) and fat free mass (FFM) standard deviation scores (SDS) generated using new body composition reference data and obtained using simple measurement methods in healthy children and patients with those obtained using the reference 4-component (4-C) model; (2) To determine the extent to which scores from simple methods agree with those from the 4-C model in identification of abnormal body composition.

Design

FM SDS were calculated for 4-C model, dual-energy X-ray absorptiometry (DXA; GE Lunar Prodigy), BMI and skinfold thicknesses (SFT); and FFM SDS for 4CM, DXA and bioelectrical impedance analysis (BIA; height²/Z)) in 927 subjects aged 3.8–22.0 y (211 healthy, 716 patients).

Results

DXA was the most accurate method for both FM and FFM SDS in healthy subjects and patients (mean bias (limits of agreement) FM SDS 0.03 (±0.62); FFM SDS −0.04 (±0.72)), and provided best agreement with the 4-C model in identifying abnormal BC (SDS ≤−2 or ≥2). BMI and SFTs were reasonable predictors of abnormal FM SDS, but poor in providing an absolute value. BIA was comparable to DXA for FFM SDS and in identifying abnormal subjects.

Conclusions

DXA may be used both for research and clinically to determine FM and FFM SDS. BIA may be used to assess FFM SDS in place of DXA. BMI and SFTs can be used to measure adiposity for groups but not individuals. The performance of simpler techniques in monitoring longitudinal BC changes requires investigation. Ultimately, the most appropriate method should be determined by its predictive value for clinical outcome.

Body fat percentile curves for Korean children and adolescents: a data from the Korea National Health and Nutrition Examination Survey 2009-2010

A valid assessment of obesity in children and adolescents is important due to significant change in body composition during growth. This study aimed to develop percentile curves of body fat and fat free mass using the Lambda, Mu, and Sigma method, and to examine the relationship among body mass index (BMI), fat mass and fat free mass in Korean children and adolescents, using the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. The study subjects were 834 for boys and 745 for girls aged between 10 and 18 yr. Fat mass and fat free mass were measured by dual-energy x-ray absorptiometry. The patterns of development in body fat percentage, fat mass and fat free mass differed for boys and girls, showing a decreased fat mass with an increased fat free mass in boys but gradual increases with age in girls. The considerable proportion of boys and girls with relatively normal fat mass appeared to be misclassified to be at risk of overweight based on the BMI criteria. Therefore, the information on the percentiles of body fat and fat free mass with their patterns would be helpful to complement assessment of overweight and obesity based on BMI for Korean children and adolescents.

Percentiles of percentage body fat in german children and adolescents: an international comparison

Background:

Age- and gender-specific percentiles of body mass index in children and adolescents are a cornerstone categorizing overweight and obesity in youths worldwide. Since corresponding worldwide growth curves of percent body fat (% BF) are missing, the purpose was to contribute smoothed percentiles of percentage body fat from a large urban sample of German youths and to include them in actual national and international percentile curves.

Methods:

We estimated % BF in 22 113 German youths aged 3 to 18 years participating in yearly cross-sectional surveys of the PEP Family Heart Study Nuremberg between 1993 and 2007. Percentage body fat was calculated from skinfold thickness using Slaughter equations. Ten smoothed percentile curves were constructed for % BF using the LMS method significant.

Results:

The age- and gender-specific reference curves demonstrate a continuous age-dependent increase of percentage body fat from age 3 to 18 years in girls; whereas in boys, the percentile curves steeply increase from 5 to 11 years and thereafter slightly decrease. The shape of the percentile curves, the maxima among boys at puberty and the median % BF at age 18 years are consistent with most of the current growth curves. % BF in urban studies seems to be lower than in national surveys .

Conclusions:

More than these nine studies should contribute to worldwide-standardized growth charts for % BF to better define overweight and obesity in youth.

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

BACKGROUND

A routine pediatric clinical assessment of body composition is increasingly recommended but has long been hampered by the following 2 factors: a lack of appropriate techniques and a lack of reference data with which to interpret individual measurements. Several techniques have become available, but reference data are needed.

OBJECTIVE

We aimed to provide body-composition reference data for use in clinical practice and research.

DESIGN

Body composition was measured by using a gold standard 4-component model, along with various widely used reference and bedside methods, in a large, representative sample of British children aged from 4 to ≥20 y. Measurements were made of anthropometric variables (weight, height, 4 skinfold thicknesses, and waist girth), dual-energy X-ray absorptiometry, body density, bioelectrical impedance, and total body water, and 4-component fat and fat-free masses were calculated. Reference charts and SD scores (SDSs) were constructed for each outcome by using the lambda-mu-sigma method. The same outcomes were generated for the fat-free mass index and fat mass index.

RESULTS

Body-composition growth charts and SDSs for 5-20 y were based on a final sample of 533 individuals. Correlations between SDSs by using different techniques were ≥0.68 for adiposity outcomes and ≥0.80 for fat-free mass outcomes.

CONCLUSIONS

These comprehensive reference data for pediatric body composition can be used across a variety of techniques. Together with advances in measurement technologies, the data should greatly enhance the ability of clinicians to assess and monitor body composition in routine clinical practice and should facilitate the use of body-composition measurements in research studies.

Adiposity in children and adolescents: correlates and clinical consequences of fat stored in specific body depots

The 2011 Pennington Biomedical Research Center's Scientific Symposium focused on adiposity in children and adolescents. The symposium was attended by 15 speakers and other invited experts. The specific objectives of the symposium were to (i) integrate the latest published and unpublished findings on the laboratory and clinical assessment of depot-specific adiposity in children and adolescents, (ii) understand the variation in depot-specific adiposity and related health outcomes associated with age, sex, maturation, ethnicity and other factors and (iii) identify opportunities for incorporating new markers of abdominal obesity into clinical practice guidelines for obesity in children and adolescents. This symposium provided an overview of important new advances in the field and identified directions for future research. The long-term goal of the symposium is to aid in the early identification of children and adolescents who are at increased health risk because of obesity and obesity-related conditions.

SECULAR TRENDS IN BODY COMPOSITION AND FREQUENCY OF OVERWEIGHT AND OBESITY IN BOYS AGED 3–18 FROM KRAKOW, POLAND, WITHIN THE LAST 30 YEARS (FROM 1983 TO 2010)

The aim of this study was to examine the changes in body composition (fatness and muscle and bone mass) and BMI in three cohorts of boys living in Krakow, Poland, over the last 30 years, and to assess how overweight and obesity frequencies have developed over the period. The anthropological survey was conducted in 2010, and comprised 1863 boys from Krakow aged 3–18 years. The analysis compared the latest measurements of selected skinfold thicknesses, BMI, total body muscle mass and bone mass with the results of surveys from 1983 (N=1934) and 2000 (N=2323). The frequency of overweight and obesity was assessed for the last survey series, and their trends determined for the years 1983–2000 and 2000–2010. The analysis of fat tissue distribution showed that the boys from the 2010 cohort, as compared with those examined in 2000, had a higher trunk adiposity, as manifested by greater thickness of subscapular and suprailiac skinfold thicknesses, and boasted a larger muscle mass and lower bone mass. The survey results also showed that, from 1983 to 2000, the percentage of overweight boys increased slightly (from 11.69% to 12.48%), whereas the frequency of obesity did not change. Over the last decade, the percentage of overweight people has increased to 15.94%, and the frequency of obesity has doubled, equalling 4.94% in 2010. The last decade has seen a minor trend in boys towards increased trunk adiposity, muscle mass, BMI and prevalence of overweight and obesity, and a slight decrease in bone mass.

Body fat percentiles for German children and adolescents

OBJECTIVE

The aim of this study was to define body fat percentiles for German children and adolescents aged 3-16 years using the largest German database.

METHODS

The study population included 11,632 girls and 11,604 boys. Data were pooled from: i) Kiel Obesity Prevention Study (KOPS), acquisition period: 1996-2008, n = 12,237; ii) 'Better diet. More exercise. KINDERLEICHT-REGIONS', acquisition period: 2007, n = 9,405; and iii) examination of Jena schoolchildren, acquisition period: 2005, n = 1,594. Body fat mass was measured by bioelectrical impedance analysis using a population-specific algorithm. Data were weighted to achieve a representative sample for Germany. Percentile curves were constructed by the LMS method and proved by Worm plots and Q-statistic.

RESULTS

In both genders, the higher body fat percentile curves sloped downwards to age 7 years, whereas the lower percentiles declined up to 8.5 years. Thereafter fat mass remained nearly constant with age in boys and increased in girls. The 10th percentile achieved a minimum of 10-11% body fat in both genders, whereas the 90th percentile curve fluctuated between 29 and 44% in boys or 30-43% in girls. The association between fat mass and blood pressure was too weak to define disease-related cut-offs.

CONCLUSION

These body fat percentiles are suitable reference values for German children and adolescents.