Body Fat Percentages by Dual-energy X-ray Absorptiometry Corresponding to Body Mass Index Cutoffs for Overweight and Obesity in Indian Children

Differential Relationship of Grip Strength with Body Composition and Lifestyle Factors Between Indian Urban and Rural Boys and Girls

OBJECTIVES

To assess grip strength and gender differences in grip strength in 9-18-y-old urban and rural Indian children, to study association of grip strength with body composition, and assess determinants of grip strength.

METHODS

This was part of a multicenter, cross-sectional, school-based study (n = 1978, mean age 13.3 ± 2.2 y) from three urban and rural states. Anthropometry, body composition, dietary intake, physical activity, sunlight exposure, and grip strength (in kg) were measured.

RESULTS

Mean grip strength increased with age but plateaued in girls after 12 y and was higher in boys (19.6 ± 9.2) than girls (14.3 ± 5.3) (p < 0.05). Mean grip strength was higher in urban (21.05 ± 9.7) than in rural boys (17.8 ± 8.2) (p < 0.05), and comparable in urban (14.9 ± 5.2) and rural girls (13.8 ± 5.5). Grip strength in girls remained lower than boys after adjusting for muscle mass. Difference between boys and girls reduced after body size [body mass index (BMI)] correction, but remained low in girls, plateauing after 15 y. Muscle mass and age were significant determinants of grip strength in all children. On addition of lifestyle factors to the model, grip strength was explained to varied degrees in the children.

CONCLUSION

In boys, nutrition through body size and composition was largely responsible for the differences in grip strength, and in girls, additionally, sociocultural factors also possibly impacted grip strength.

A pro-inflammatory diet increases the likelihood of obesity and overweight in adolescent boys: a case-control study

BACKGROUND

Obesity and Overweight at an early age can contribute with many chronic diseases such as cancers, diabetes and cardiovascular diseases. Diet-related inflammation is one of the most important underlying mechanisms that may has a key role in obesity and overweight. This paper aimed to compare the dietary inflammatory index (DII^®) in normal weight and overweight adolescent boys.

METHODS

A total of 535 adolescent boys (214 cases were overweight and obese and 321 controls with normal weight) participated in this study from two schools in Tehran, Iran. The student's weight and body composition were measured using a Bio-Impedance Analyzer (BIA) scale. A validated semi-quantitative Food Frequency Questionnaire (FFQ) was used to assess dietary inflammatory index.

RESULTS

Results obtained from modeling DII^® as a continuous variable identified a positive association between DII^® and obesity (OR = 1.08, CI 1.01-1.16). After multivariable adjustment, subjects with DII^® > 0.02 had at 1.5 times higher odds of obesity and overweight compared to subjects with DII^® ≤ 0.02 (OR = 1.52; CI 1.04-2.22).

CONCLUSION

Our study indicated the importance of dietary-induced inflammation in the obesity and overweight during adolescence. Therefore, advising adolescent to consume diet with lower DII^® with more fruits and vegetables, rich sources of fiber, flavonoids, zinc, magnesium and selenium and avoiding the consumption of saturated fatty acids (SFA), trans-fatty acids, and cholesterol may support a healthy weight.

Obesity measured as percent body fat, relationship with body mass index, and percentile curves for Mexican pediatric population

In Mexico, the increase in childhood obesity is alarming. Thus, improving the precision of its diagnosis is expected to impact on disease prevention. We estimated obesity prevalence by bioimpedance-based percent body fat (%BF) and body mass index (BMI) in 1061 girls and 1121 boys, from 3 to 17 years old. Multiple regressions and area under receiver operating curves (AUC) were used to determine the predictive value of BMI on %BF and percentile curves were constructed. Overall obesity prevalence estimated by %BF was 43.7%, and by BMI it was 20.1%; it means that the diagnosis by BMI underestimated around 50% of children diagnosed with obesity by %BF (≥30% for girls, ≥25% for boys). The fat mass excess is further underestimated in boys than in girls when using the standard BMI classification. The relationship between %BF and BMI was strong in school children and adolescents (all cases R2>0.70), but not in preschool children (girls R2 = 0.57, boys R2 = 0.23). AUCs showed greater discriminative power of BMI to detect %BF obesity in school children and adolescents (all cases AUC≥0.90) than in preschool children (girls AUC = 0.86; boys AUC = 0.70). Growth percentile charts showed that girls aged 9-17 years and boys aged 8-17 years presented fat excess from the 50th percentile and above. We suggested to change the BMI cut-off for them, considering values at the 75th percentile as overweight, and values at the 85th percentile as obesity, as previously recommended for Mexican children. Improving obesity diagnosis will allow greater efficiency when searching for comorbidities in clinical practice.

Body composition techniques

Body composition is known to be associated with several diseases, such as cardiovascular disease, diabetes, cancers, osteoporosis and osteoarthritis. Body composition measurements are useful in assessing the effectiveness of nutritional interventions and monitoring the changes associated with growth and disease conditions. Changes in body composition occur when there is a mismatch between nutrient intake and requirement. Altered body composition is observed in conditions such as wasting and stunting when the nutritional intake may be inadequate. Overnutrition on the other hand leads to obesity. Many techniques are available for body composition assessment, which range from simple indirect measures to more sophisticated direct volumetric measurements. Some of the methods that are used today include anthropometry, tracer dilution, densitometry, dual-energy X-ray absorptiometry, air displacement plethysmography and bioelectrical impedance analysis. The methods vary in their precision and accuracy. Imaging techniques such as nuclear magnetic resonance imaging and computed tomography have become powerful tools due to their ability of visualizing and quantifying tissues, organs, or constituents such as muscle and adipose tissue. However, these methods are still considered to be research tools due to their cost and complexity of use. This review was aimed to describe the commonly used methods for body composition analysis and provide a brief introduction on the latest techniques available.

Body Composition Percentiles in Urban South Indian Children and Adolescents

OBJECTIVE

This study aimed to generate age- and sex-specific percentiles for body composition indices in children and to assess the variability in these indices, in relation to BMI.

METHODS

Anthropometry and body fat were measured with the BOD POD (Cosmed; Rome, Italy) in 9,702 children from Bangalore, India. Smoothed percentile curves using the lambda-mu-sigma method were obtained for BMI, fat-free mass index (FFMI), fat mass index (FMI), and body fat percentage (% BF).

RESULTS

Percentile curves for % BF and FMI in boys increased from 6 to 12 years and declined from 13 years on, while in girls, it increased until 15 years. The FFMI percentile curves increased with age in both sexes. The mean FMI declined from 12 years on in boys, corresponding to a large increase in FFMI from that age, while in girls, both FMI and FFMI continued to increase. The 75th percentile of % BF and FMI had greater sensitivity to identify children with obesity.

CONCLUSIONS

This study developed smoothed percentile curves for body composition in Indian children and suggests FMI and FFMI as good indicators of growth in children.

Triponderal mass index rather than body mass index: An indicator of high adiposity in Italian children and adolescents

OBJECTIVE

The aims of this study were to compare body mass index (BMI) and triponderal mass index (TMI) as predictors of fat mass percentage (FM%) and to develop TMI cutoffs for screening high adiposity. Therefore, TMI- and BMI-based references against FM% criterion for indicating adiposity in Italian children and adolescents were compared.

METHODS

This was a cross-sectional study conducted at the University of Rome Tor Vergata, Human Nutrition Unit, from 2008 to 2015. The sample included 485 children and adolescents from 8 to 17 y of age from central-southern Italy. Body weight (kg) and height (m) were assessed to calculate BMI and TMI. FM% was assessed by dual-energy x-ray absorptiometry. The prevalence of high adiposity was based on the 75th percentile of FM%, according to Ogden et al. curves. Statistical tests such as Mann-Whitney, Kruskal-Wallis, polynomial regression, receiver operating characteristics curve, and Cohen's κ, were performed using SPSS version 24 and MedCalc version 18.

RESULTS

Prevalence of high adiposity according to FM% was 50.2% (95% confidence interval [CI], 43.2-57.2) in boys and 43.2% (95% CI, 37.3-49.2) in girls. TMI rather than BMI could better predict FM% for both sexes (boys R² = 0.67 and girls R² = 0.79 versus boys R² = 0.44 and girls R² = 0.74, respectively). TMI was found to present a significantly higher area under the curve than BMI for indicating high adiposity in children and adolescents. TMI sex- and age-specific cutoffs were responsible by better classification of adiposity, followed by the International Obesity Task Force, World Health Organization, and Cacciari reference curves.

CONCLUSION

TMI is a useful screening tool in pediatric clinical practice and epidemiologic studies concerning childhood obesity.

Simple tests for the diagnosis of childhood obesity: a systematic review and meta-analysis

There is a need to accurately quantify levels of adiposity in order to identify overweight and obesity in children. This systematic review aimed to identify all diagnostic accuracy studies evaluating simple tests for obesity and adiposity, including body mass index (BMI), skin-fold thickness and waist circumference, compared against high-quality reference tests. Twenty-four cohort studies including 25,807 children were included. BMI had good performance when diagnosing obesity: a sensitivity of 81.9% (95% confidence interval [CI]: 73.0 to 93.8) for a specificity of 96.0% (95% CI: 93.8 to 98.1). It was less effective at diagnosing overweight (sensitivity: 76.3%, 95% CI: 70.2 to 82.4; specificity: 92.1% 95% CI: 90.0 to 94.3). When diagnosing obesity, waist circumference had similar performance (sensitivity: 83.8%; specificity: 96.5%). Skin-fold thickness had slightly poorer performance (sensitivity: 72.5%; specificity: 93.7%). Few studies considered any other tests. There was no conclusive evidence that any test was generally superior to the others. BMI is a good simple diagnostic test for identifying childhood adiposity. It identifies most genuinely obese and adipose children while misclassifying only a small number as obese. There was no conclusive evidence that any test should be preferred to BMI, and the extra complexity of skin-fold thickness tests does not appear to improve diagnostic accuracy.

The use of measures of obesity in childhood for predicting obesity and the development of obesity-related diseases in adulthood: a systematic review and meta-analysis

BACKGROUND

It is uncertain which simple measures of childhood obesity are best for predicting future obesity-related health problems and the persistence of obesity into adolescence and adulthood.

OBJECTIVES

To investigate the ability of simple measures, such as body mass index (BMI), to predict the persistence of obesity from childhood into adulthood and to predict obesity-related adult morbidities. To investigate how accurately simple measures diagnose obesity in children, and how acceptable these measures are to children, carers and health professionals.

DATA SOURCES

Multiple sources including MEDLINE, EMBASE and The Cochrane Library were searched from 2008 to 2013.

METHODS

Systematic reviews and a meta-analysis were carried out of large cohort studies on the association between childhood obesity and adult obesity; the association between childhood obesity and obesity-related morbidities in adulthood; and the diagnostic accuracy of simple childhood obesity measures. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and a modified version of the Quality in Prognosis Studies (QUIPS) tool. A systematic review and an elicitation exercise were conducted on the acceptability of the simple measures.

RESULTS

Thirty-seven studies (22 cohorts) were included in the review of prediction of adult morbidities. Twenty-three studies (16 cohorts) were included in the tracking review. All studies included BMI. There were very few studies of other measures. There was a strong positive association between high childhood BMI and adult obesity [odds ratio 5.21, 95% confidence interval (CI) 4.50 to 6.02]. A positive association was found between high childhood BMI and adult coronary heart disease, diabetes and a range of cancers, but not stroke or breast cancer. The predictive accuracy of childhood BMI to predict any adult morbidity was very low, with most morbidities occurring in adults who were of healthy weight in childhood. Predictive accuracy of childhood obesity was moderate for predicting adult obesity, with a sensitivity of 30% and a specificity of 98%. Persistence of obesity from adolescence to adulthood was high. Thirty-four studies were included in the diagnostic accuracy review. Most of the studies used the least reliable reference standard (dual-energy X-ray absorptiometry); only 24% of studies were of high quality. The sensitivity of BMI for diagnosing obesity and overweight varied considerably; specificity was less variable. Pooled sensitivity of BMI was 74% (95% CI 64.2% to 81.8%) and pooled specificity was 95% (95% CI 92.2% to 96.4%). The acceptability to children and their carers of BMI or other common simple measures was generally good.

LIMITATIONS

Little evidence was available regarding childhood measures other than BMI. No individual-level analysis could be performed.

CONCLUSIONS

Childhood BMI is not a good predictor of adult obesity or adult disease; the majority of obese adults were not obese as children and most obesity-related adult morbidity occurs in adults who had a healthy childhood weight. However, obesity (as measured using BMI) was found to persist from childhood to adulthood, with most obese adolescents also being obese in adulthood. BMI was found to be reasonably good for diagnosing obesity during childhood. There is no convincing evidence suggesting that any simple measure is better than BMI for diagnosing obesity in childhood or predicting adult obesity and morbidity. Further research on obesity measures other than BMI is needed to determine which is the best tool for diagnosing childhood obesity, and new cohort studies are needed to investigate the impact of contemporary childhood obesity on adult obesity and obesity-related morbidities.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005711.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Concordance of obesity classification between body mass index and percent body fat among school children in Saudi Arabia

Background

In Saudi Arabia, where childhood obesity is a major public health issue, it is important to identify the best tool for obesity classification. Hence, we compared two field methods for their usefulness in epidemiological studies.

Methods

The sample consisted of 874 primary school (grade I-IV) children, aged 6–10 years, and was obtained through a multi-stage random sampling procedure. Weight and height were measured, and BMI (kg/m²) was calculated. Percent body fat was determined with a Futrex analyzer that uses near infrared reactance (NIR) technology. Method specific cut-off values were used for obesity classification. Sensitivity, specificity, positive and negative predictive values were determined for BMI, and the agreement between BMI and percent body fat was calculated.

Results

Compared to boys, the mean BMI was higher in girls whereas the mean percent body fat was lower (p-values <0.0001). According to BMI, the prevalence of overweight or obesity was significantly higher in girls (34.3% vs. 17.3%); as oppose to percent body fat, which was similar between the sexes (6.6% vs. 7.0%). The sensitivity of BMI to classify overweight or obesity was high (boys =93%, girls = 100%); and its false-positive detection rate was also high (boys = 63%, girls = 81%). The agreement rate was low between these two methods (boys = 0.48, girls =0.24).

Conclusions

There is poor agreement in obesity classification between BMI and percent body fat, using NIR method, among Saudi school children.

Assessment of body composition in Indian adults: comparison between dual-energy X-ray absorptiometry and isotope dilution technique

Dual-energy X-ray absorptiometry (DXA) and isotope dilution technique have been used as reference methods to validate the estimates of body composition by simple field techniques; however, very few studies have compared these two methods. We compared the estimates of body composition by DXA and isotope dilution (¹⁸O) technique in apparently healthy Indian men and women (aged 19–70 years, n 152, 48 % men) with a wide range of BMI (14–40 kg/m²). Isotopic enrichment was assessed by isotope ratio mass spectroscopy. The agreement between the estimates of body composition measured by the two techniques was assessed by the Bland–Altman method. The mean age and BMI were 37 (sd 15) years and 23·3 (sd 5·1) kg/m², respectively, for men and 37 (sd 14) years and 24·1 (sd 5·8) kg/m², respectively, for women. The estimates of fat-free mass were higher by about 7 (95 % CI 6, 9) %, those of fat mass were lower by about 21 (95 % CI − 18, − 23) %, and those of body fat percentage (BF%) were lower by about 7·4 (95 % CI − 8·2, − 6·6) % as obtained by DXA compared with the isotope dilution technique. The Bland–Altman analysis showed wide limits of agreement that indicated poor agreement between the methods. The bias in the estimates of BF% was higher at the lower values of BF%. Thus, the two commonly used reference methods showed substantial differences in the estimates of body composition with wide limits of agreement. As the estimates of body composition are method-dependent, the two methods cannot be used interchangeably.

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.

Arterial stiffness in obese children: Role of adiposity and physical activity

OBJECTIVE

To explore association of adiposity and physical activity with arterial stiffness and to propose optimal waist circumference cutoffs, corresponding to 90(th) percentile of NHANES (National Health and Nutrition Examination Survey) for Indian children and adolescents.

MATERIALS AND METHODS

Data on weight, height, waist circumference, physical activity and right Carotid artery Intima-Media-Thickness (CIMT), pulse wave velocity (PWV), elasticity modulus (Ep), stiffness index(β), arterial compliance (AC) were assessed in 250 children (72 normal-weight and 178 overweight/obese) aged 6-17 years from Pune city, India. Body composition was measured using Dual energy X-ray absorptiometry.

RESULTS

Total, 37.1% normal-weight and 98.2% overweight/obese children had high adiposity (>95(th) body fat percentile). Positive association of PWV and Ep (r = 0.5) also β(r = 0.25) with BMI (Body Mass Index), waist circumference and body fat (P < 0.05) was observed. Physical activity was inversely associated with PWV (r =-0.2), β(r =-0.13), Ep (r =-0.12) and positively with AC (r = 0.12) (P < 0.05). PWV significantly increased with increasing body fat for each tertile of physical activity (P < 0.05). Regression analysis revealed waist circumference, BMI, body fat and physical activity as independent associates for PWV after adjusting for age (P < 0.05). The cutoff of waist circumference yielding sensitivity and specificity for predicting the risk of high PWV was (-0.43, -0.44) for boys and girls with sensitivity in boys (girls) of 78% (87%) and specificity in boys (girls) 51% (70%). The observed cutoffs are less than the NHANES-III cutoff values of waist circumference for 90(th) percentiles according to age and sex.

CONCLUSION

High adiposity and low physical activity are adversely related to arterial stiffness in Indian children.

Metabolic risk factors and arterial stiffness in Indian children of parents with metabolic syndrome

OBJECTIVE

To investigate the possible association between metabolic syndrome (MS) and arterial stiffness in Indian children with parental MS status.

METHODS

A cross-sectional study was conducted in 140 overweight/obese and 60 normal-weight Indian children (mean age, 11.4 ± 2.8 years) along with one of their parents during 2008-2009. Data on weight, height, blood pressure, serum lipids, zinc, insulin, and glucose were collected. Intima media thickness (CIMT) and stiffness parameters were assessed in the right carotid artery. Physical activity and diet were assessed using structured questionnaires. Body composition was measured using dual-energy x-ray absorptiometry.

RESULTS

A gradual increase in the percentage of MS children with an increasing number of MS components in parents was observed. Mean values for arterial stiffness, pulse wave velocity, and elastic modulus were significantly higher in MS children of MS parents than in MS children of normal parents (p < 0.05). A significant correlation was observed for lifestyle, metabolic, and arterial parameters among child-parent pairs (p < 0.05). Multiple logistic regression revealed that children's CIMT and arterial stiffness were significantly associated (p < 0.01) with their serum levels of triglycerides, high-density lipoprotein, and zinc, as well as with parental MS-CIMT.

CONCLUSION

Parental MS status and lifestyle factors increase the risk of MS and arterial abnormalities in children.

Relationship between body mass index, fat distribution and cardiometabolic risk factors in Indian children and adolescents

BACKGROUND

Studies assessing the relationship of BMI and BF with cardiometabolic (CM) risks in Indian children are scarce.

OBJECTIVE

To assess the occurrence of cardiometabolic risk factors in Indian children and adolescents in relation to BMI and body fat and to study their association with body fat distribution.

METHODS

286 children and adolescents (mean age 11.2 ± 2.6 years, 139 boys) were recruited from routine health checks and schools. Anthropometry and blood pressure were recorded, total body fat (BF) and fat distribution (android and gynoid) were measured by Dual Energy X-ray Absorptiometry. Fasting plasma glucose, lipid profile and insulin were also measured.

RESULTS

When the study cohort was divided as per their BMI and biochemical cardiometabolic risk factors, 8% children had normal BMI with abnormal biochemical parameters while 40% children had abnormal BMI but normal biochemical parameters.

CONCLUSION

There are normal weight children with cardiometabolic risks. There was an increase in the occurrence of cardiometabolic risk factors with increased android distribution of fat (p-value < 0.05).

Carotid arterial stiffness in overweight and obese Indian children

OBJECTIVE

The aim of the study was to evaluate carotid arterial stiffness and intima media thickness (IMT) in obese children in comparison with healthy children, and to examine associations of lipid profile and blood pressure with carotid artery morphology.

METHODS

Anthropometric and blood parameters were assessed in 44 overweight, 95 obese (6-17 years) and 69 healthy age-matched normal children. Percent body fat was measured by dual-energy X-ray absorptiometry and stiffness and IMT of the common carotid artery were evaluated using Aloka alpha 10 equipment.

RESULTS

Anthropometric and lipid parameters were significantly higher in overweight and obese than in normal children (p < 0.05). Stiffness (beta), pulse wave velocity (PWV), elastic modulus (Ep) and blood pressure were significantly higher in obese and overweight children than in normal children (p < 0.05). However, overweight and obese children did not show any significant difference in IMT compared with normal children (p > 0.1). Significant positive correlation of PWV, beta and Ep and negative correlation of arterial compliance with body fat and triglyceride was noted (p < 0.05). Different multinomial regression models for each e-Tracking parameter indicated that the relative risk of hypertension was highest with high PWV, followed by LDL cholesterol, Ep and body fat.

CONCLUSION

PWV may be considered an important marker for evaluation of early functional changes of the carotid artery in children and adolescents.