Prediction of body-fat percentage from skinfold and bio-impedance measurements in Indian school children

Comparison of Several Prediction Equations Using Skinfold Thickness for Estimating Percentage Body Fat vs. Body Fat Percentage Determined by BIA in 6-8-Year-Old South African Children: The BC-IT Study

Body composition measurement is useful for assessing percentage body fat (%BF) and medical diagnosis, monitoring disease progression and response to treatment, and is essential in assessing nutritional status, especially in children. However, finding accurate and precise techniques remains a challenge. The study compares %BF determined by bioelectrical impedance analysis (BIA) and calculated from available prediction equations based on skinfolds in young South African children. A cross-sectional study performed on 202 children (83 boys and 119 girls) aged 6-8 years. Height and weight, triceps and subscapular skinfolds were determined according to standard procedures. %BF was determined with BIA and three relevant available equations. SPSS analyzed the data using paired samples tests, linear regression, and Bland-Altman plots. Significant paired mean differences were found for BIA and Slaughter (t₂₀₁ = 33.896, p < 0.001), Wickramasinghe (t₂₀₁ = 4.217, p < 0.001), and Dezenberg (t₂₀₁ = 19.910, p < 0.001). For all of the equations, the standards for evaluating prediction errors (SEE) were above 5. The Bland-Altman plots show relatively large positive and negative deviations from the mean difference lines and trends of systematic under- and over-estimation of %BF across the %BF spectrum. All three equations demonstrated a smaller %BF than the %BF measured by BIA, but the difference was smallest with the Wickramasinghe equation. In comparison, a poor SEE was found in the three %BF predicted equations and %BF derived from BIA. As such, an age-specific %BF equation incorporating criterion methods of deuterium dilution techniques or 'gold-standard' methods is needed to refute these findings. However, in the absence of developed %BF equations or 'gold-standard' methods, the available prediction equations are still desirable.

Validity and accuracy of body fat prediction equations using anthropometric measurements in children 7 – 10 years old

abstract Children with a deficit of growth because of perinatal malnutrition present specificities in the percentage of body fat (%BF) that could not be detected by previous fat mass-based equations. This study developed and validated predictive equations of the %BF derived from anthropometric variables in children aged 7 to 10 living in Northeast Brazil, using dual-energy x-ray absorptiometry (DXA) as a reference. Body composition data from 58 children were utilized. DXA was used as a reference. A stepwise (forward) multiple regression statistical model was used to develop the new equations. The Bland-Altman analysis (CI: 95%), paired Student's t-test, and the intraclass correlation coefficient (ICC) was used to validate and compare the developed equations. Two new equations were developed for either gender: boys: %BF: 13.642 + (1.527*BMI) + (-0.345*Height) + (0.875*Triceps) + (0.290* Waist Circumference) and girls: %BF: -13.445 + (2.061*Tight). The Bland-Altman analysis showed good agreement, with limits ranging from -1.33 to 1.24% for boys and -3.35 to 4.08% for girls. The paired Student’s t-test showed no difference between %BF-DXA and the two new equations (p> 0.05), and the ICC was 0.948 and 0.915, respectively. DXA-based anthropometric equations provide an accurate and noninvasive method to measure changes in the %BF in children.

Development of population-specific prediction equations for bioelectrical impedance analyses in Vietnamese children

There is a need for accurate, inexpensive and field-friendly methods to assess body composition in children. Bioelectrical impedance analysis (BIA) is a promising approach; however, there have been limited validation and use among young children in resource-poor settings. We aim to develop and validate population-specific prediction equations for estimating total fat mass (FM), fat free-mass (FFM) and percentage body fat (PBF) in Vietnamese children (4-7 years) using reactance and resistance from BIA, anthropometric variables and demographic information. We conducted a cross-sectional survey of 120 children. Body composition was measured using dual-energy X-ray absorptiometry (DXA), BIA and anthropometry. To develop prediction equations, we split all data into development (70 %) and validation datasets (30 %). The model performance was evaluated using predicted residual error sum of squares, root mean squared error (RMSE), mean absolute error (MAE) and R2. We identified a top performing model with the least number of parameters (age, sex, weight and resistance index or resistance and height), low RMSE (FM 0·70, FFM 0·74, PBF 3·10), low MAE (FM 0·55, FFM 0·62, PBF 2·49), high R2 (FM 0·95, FFM 0·92, PBF 0·82) and the least difference between predicted values and actual values from DXA (FM 0·03 kg or 0·01 sd, FFM 0·06 kg or 0·02 sd, PBF 0·27 % or 0·04 sd). In conclusion, we developed the first valid and highly predictive equations to estimate FM, FFM and PBF in Vietnamese children using BIA. These findings have important implications for future research on the double burden of disease and risks associated with overweight and obesity in young children.

Predictive anthropometric models of total and truncal body fat in Chilean children

OBJECTIVES

This study aimed to develop predictive anthropometric models for total and truncal body fat in Chilean children using the following anthropometric measurements: weight, height, skinfold thickness, and circumference.

METHODS

This cross-sectional study included 669 Chilean children (12.0 y ± 1.3) in Tanner stage IV from the Growth and Obesity Chilean Cohort Study. Anthropometric measurements and dual-energy X-ray absorptiometry were determined to calculate total and truncal body fat. Prediction models were fitted by linear regression analysis.

RESULTS

The predictive equation for log total body fat (kg) was 0.449 + 0.049 (body mass index in kg/m²) + 0.018 (triceps skinfold in mm) + 0.012 (biceps skinfold in mm) + 0.019 (brachial circumference in cm) + 0.091 (sex: 1 = boy, 2 = girl) + 0.018 (age in y). The predictive equation for log truncal fat (kg) was -2.107 + 0.046 (waist circumference in cm) + 0.010 (subscapular skinfold in mm) + 0.259 (sex: 1 = boy, 2 = girl) + 0.006 (age in y). The test of concordance between the predictive equations of total and truncal body fat with gold standard was r = 0.85 and 0.91, respectively.

CONCLUSIONS

In Chilean children, the high correlation between observed and predicted values enabled us to develop predictive equations for total and truncal body fat for children.

Utility of published skinfold thickness equations for prediction of body composition in very young New Zealand children

Measurement of body composition is increasingly important in research and clinical settings but is difficult in very young children. Bioelectrical impedance analysis (BIA) and air displacement plethysmography (ADP) are well-established but require specialist equipment so are not always feasible. Our aim was to determine if anthropometry and skinfold thickness measurements can be used as a substitute for BIA or ADP for assessing body composition in very young New Zealand children. We used three multi-ethnic cohorts: 217 children at a mean age of 24·2 months with skinfold and BIA measurements; seventy-nine infants at a mean age of 20·9 weeks and seventy-three infants at a mean age of 16·2 weeks, both with skinfold and ADP measurements. We used Bland-Altman plots to compare fat and fat-free mass calculated using all potentially relevant equations with measurements using BIA or ADP. We also calculated the proportion of children in the same tertile for measured fat or fat-free mass and tertiles (i) calculated using each equation, (ii) each absolute skinfold, and (iii) sum of skinfold thicknesses. We found that even for the best equation for each cohort, the 95 % limits of agreement with standard measures were wide (25-200 % of the mean) and the proportion of children whose standard measures fell in the same tertile as the skinfold estimates was ≤69 %. We conclude that none of the available published skinfold thickness equations provides good prediction of body composition in multi-ethnic cohorts of very young New Zealand children with different birth history and growth patterns.

Active children are less adipose and insulin resistant in early adolescence; evidence from the Mysore Parthenon Cohort

Background

The aim of this study was to determine whether physical activity volume and intensity in mid-childhood and early adolescence were associated with cardiometabolic risk factors at 13.5 years.

Methods

Participants were recruited from the Mysore Parthenon observational birth cohort. At ages 6–10 and 11–13 years, volume and intensity of physical activity were assessed using AM7164 or GT1M actigraph accelerometers worn for ≥4 days, and expressed as mean counts per day and percentage time spent in light, moderate and vigorous physical activity according to criteria defined by Evenson et al. At 13.5 years, fasting blood samples were collected; lipids, glucose and insulin concentrations were measured and insulin resistance (HOMA) was calculated. Systolic and diastolic blood pressure were measured at the left arm using a Dinamap (Criticon). Anthropometry and bio-impedance analysis were used to assess body size and composition. Metabolic and anthropometric measures were combined to produce a metabolic syndrome risk score.

Results

At 6–10 years, boys and girls respectively spent a median (IQR) of 1.1 (0.5, 2.0) % and 0.8 (0.4, 1.3) % of recorded time vigorously active. At 11–13 years, boys and girls respectively spent a median (IQR) of 0.8 (0.4, 1.7) % and 0.3 (0.1, 0.6) % of time vigorously active. All of the physical activity parameters were positively correlated between the 6–10 year and the 11–13 year measurements indicating that physical activity tracked from childhood to early adolescence. There were no associations between physical activity at 6–10 years and individual 13.5 year risk factors but % time vigorously active was inversely associated with metabolic syndrome score (B = −0.40, 95% CI −0.75, 0.05). Volume of physical activity at 11–13 years was inversely associated with 13.5 year HOMA and fat percentage and vigorous physical activity was associated with HOMA, fat percentage, sum of skinfolds, waist circumference and total: HDL cholesterol ratio. Vigorous physical activity was inversely associated with metabolic syndrome score (B = −0.51, 95% CI −0.94, −0.08).

Conclusions

Volume and intensity of physical activity in early adolescence were negatively associated with metabolic and anthropometric risk factors. Interventions that aim to increase adolescent physical activity, especially vigorous, may prevent cardiometabolic disease in later life.

A Comparative Study on Fat Pattern between Tribal and Non-tribal Girls of Tripura, North-East India

OBJECTIVE

To examine the body composition including fat patterning among 744 school going Chakma tribal and non- tribal Bengali girls (366 Chakma tribal and 378 Bengali girls), aged 6-12y from North, Unokoti, Dhalai and South District of Tripura.

METHODS

The subjects were selected using cluster-random sampling method. The anthropometric measurements of height, weight, triceps and subscapular skinfold were recorded. The body mass index (BMI) was also calculated. The measurements were used to estimate percent body fat (PBF) and fat-free mass (FFM) from skinfolds. Fat mass (FM) and FFM were each divided by height squared to produce the fat-mass index (FMI) and fat-free mass index (FFMI). Body composition was assessed using FM, FFM, FMI and FFMI.

RESULTS

Age-specific mean values of FM ranged from 2.65-6.75 kg (tribal) and 1.92-6.45 kg (non-tribal). Age-specific mean values of FFM ranged from 17.19-29.61 kg for tribals and 15.41-28.44 kg for non-tribals respectively. PBF of tribals was significantly (p < 0.01) higher (except 10 y) than non-tribals. FFM and PBF significantly (p < 0.01) related with all anthropometric variables.

CONCLUSIONS

This study suggested a clear evidence of ethnic variation in fat patterning; Chakma tribal girls showing a greater subcutaneous adiposity in comparison with Bengali girls. These results are important for future investigations in clinical and epidemiological studies to identify the risk of lower or higher adiposity and body composition.

Effect of Ramadan Fasting on Weight and Body Composition in Healthy Non-Athlete Adults: A Systematic Review and Meta-Analysis

Background: Ramadan involves one month of fasting from sunrise to sunset. In this meta-analysis, we aimed to determine the effect of Ramadan fasting on weight and body composition. Methods: In May 2018, we searched six databases for publications that measured weight and body composition before and after Ramadan, and that did not attempt to influence physical activity or diet. Results: Data were collected from 70 publications (90 comparison groups, 2947 participants). There was a significant positive correlation between starting body mass index and weight lost during the fasting period. Consistently, there was a significant reduction in fat percentage between pre-Ramadan and post-Ramadan in people with overweight or obesity (−1.46 (95% confidence interval: −2.57 to −0.35) %, p = 0.010), but not in those of normal weight (−0.41 (−1.45 to 0.63) %, p = 0.436). Loss of fat-free mass was also significant between pre-Ramadan and post-Ramadan, but was about 30% less than loss of absolute fat mass. At 2–5 weeks after the end of Ramadan, there was a return towards, or to, pre-Ramadan measurements in weight and body composition. Conclusions: Even with no advice on lifestyle changes, there are consistent—albeit transient—reductions in weight and fat mass with the Ramadan fast, especially in people with overweight or obesity.

Comparing BMI with skinfolds to estimate age at adiposity rebound and its associations with cardio-metabolic risk markers in adolescence

Background

Body mass index (BMI) reaches a nadir in mid-childhood, known as the adiposity rebound (AR). Earlier AR is associated with a higher risk of cardio-vascular diseases in later life. Skinfolds, which are a more direct measure of adiposity, may give better insight into the relationship between childhood adiposity and later obesity and cardio-metabolic risk.

Objective

We aimed to assess whether AR corresponds to a rebound in skinfolds, and compare associations of BMI-derived AR and skinfold-derived AR with cardio-metabolic risk markers in adolescence.

Methods

We used penalised splines with random coefficients to estimate BMI and skinfold trajectories of 604 children from the Mysore Parthenon Birth Cohort. Age at AR was identified using differentiation of the BMI and skinfold growth curves between 2 and 10 years of age. At 13.5 years, we measured blood pressure, and glucose, insulin and lipid concentrations.

Results

BMI and skinfolds had different growth patterns. Boys reached BMI-derived AR earlier than skinfold-derived AR (estimated difference: 0.41 years; 95% CI:[0.23, 0.56]), whereas the opposite was observed in girls (estimated difference: −0.71 years; 95% CI:[−0.90, −0.54]). At 13.5 years, children with earlier BMI-derived AR had higher BMI (−0.58 SD per SD increase of AR; 95%CI:[−0.65, −0.52]), fat mass (−0.44; 95%CI:[−0.50, −0.37]), insulin resistance (HOMA-IR: −0.20; 95%CI:[−0.28, −0.12]) and systolic blood pressure (−0.20; 95%CI:[−0.28, −0.11]), and lower HDL-cholesterol (0.12; 95%CI:[0.04, 0.21]). The associations were independent of BMI at time of rebound, but were fully explained by fat mass at 13.5 years. Similar associations were found for skinfold-derived AR.

Conclusion

BMI-derived adiposity rebound predicts later cardio-metabolic risk markers similarly to that derived from skinfolds, a direct measure of adiposity.

Equations based on anthropometry to predict body fat measured by absorptiometry in schoolchildren and adolescents

OBJECTIVE

To develop and validate equations to estimate the percentage of body fat of children and adolescents from Mexico using anthropometric measurements.

METHODS

A cross-sectional study was carried out with 601 children and adolescents from Mexico aged 5-19 years. The participants were randomly divided into the following two groups: the development sample (n=398) and the validation sample (n=203). The validity of previously published equations (e.g., Slaughter) was also assessed. The percentage of body fat was estimated by dual-energy X-ray absorptiometry. The anthropometric measurements included height, sitting height, weight, waist and arm circumferences, skinfolds (triceps, biceps, subscapular, supra-iliac, and calf), and elbow and bitrochanteric breadth. Linear regression models were estimated with the percentage of body fat as the dependent variable and the anthropometric measurements as the independent variables.

RESULTS

Equations were created based on combinations of six to nine anthropometric variables and had coefficients of determination (r²) equal to or higher than 92.4% for boys and 85.8% for girls. In the validation sample, the developed equations had high r² values (≥85.6% in boys and ≥78.1% in girls) in all age groups, low standard errors (SE≤3.05% in boys and ≤3.52% in girls), and the intercepts were not different from the origin (p>0.050). Using the previously published equations, the coefficients of determination were lower, and/or the intercepts were different from the origin.

CONCLUSIONS

The equations developed in this study can be used to assess the percentage of body fat of Mexican schoolchildren and adolescents, as they demonstrate greater validity and lower error compared with previously published equations.

Body composition estimation in children and adolescents by bioelectrical impedance analysis: A systematic review

BACKGROUND

Bioelectrical impedance analysis (BIA) has commonly been used to assess the body composition of children and adolescents. BIA validation studies have found distinct correlation values with reference methods.

OBJECTIVES

To assess the reproducibility, correlation and mean differences in body composition estimated by BIA and reference methods, we systematically reviewed the literature in the pediatric population.

METHOD

The search for articles was conducted in March 2016 and was limited to articles published from 2005 to 2015 in the PubMed, Embase, EBSCO, Web of Science, Scopus and SciELO databases. Two reviewers independently performed data selection and extraction of studies that investigated the BIA validity, responsiveness, reliability and/or measurement error (reproducibility) to estimate body composition in children and adolescents with an average age ≤ 18 years.

RESULTS

The search produced 48 articles. Almost perfect reproducibility was found in the body fat percentage estimated by BIA, and there was almost perfect correlation between the BIA ratings and reference methods for fat mass and fat-free mass. Regarding component estimates, BIA underestimated the fat mass in both sexes.

CONCLUSIONS

The body fat percentage estimated by BIA exhibited almost perfect reproducibility. The fat mass and fat-free mass estimated by BIA correlated almost perfectly with the reference methods in both sexes. BIA underestimated the fat mass in both sexes.

Baseline Body Composition in Prepubertal Short Stature Children with Severe and Moderate Growth Hormone Deficiency

Objective. To compare body composition parameters in short children with severe versus moderate and no growth hormone deficiency (GHD). Design and Method. 61 children (40 boys) were studied. Height SDS, BMI Z-score, waist/height ratio (W/HtR), and body composition parameters (BIA) as fat tissue (FAT%), fat-free mass (FFM%), predicted muscle mass (PMM%), and total body water (TBW%) were evaluated. GH secretion in the overnight profile and two stimulation tests and insulin-like growth factor 1 (IGF-1) level were measured. Results. Overall, in 16 (26%) moderate (7.0 > peak GH < 10 ng/mL) and in 11 (18%) severe (GH ≤ 7.0 ng/mL) GHD was diagnosed. In children with sGHD BMI Z-score, W/HtR and FAT% were significantly higher, while FFM%, PMM%, and TBW% were significantly lower versus mGHD and versus noGHD subgroups. No significant differences between mGHD and noGHD were found. There were no differences in height SDS and IGF-1 SDS between evaluated subgroups. Night GH peak level correlated significantly with FAT%, FFM%, PMM%, and TBW%, (p < 0.05) in the entire group. Conclusions. Only sGHD is associated with significant impairment of body composition. Body composition analysis may be a useful tool in distinguishing between its severe and moderate form of GHD.

Differences in the anthropometry of Asian children and its role in metabolic health in later life: A narrative review

BACKGROUND

The increasing incidence of childhood obesity in Asia could be a reflection of early life programming in which environmental/nutritional challenges during pregnancy and first two years of life (the so-called first 1000 days) influence later health.

OBJECTIVE OF NARRATIVE REVIEW

To assess differences/similarities of anthropometric measures in early life and their influences on metabolic health risk in later life among children in Asia.

METHODS

Literature search for publication in English using selected key words from Medline (PubMed), Scopus, Science Direct and Google Scholar published from 1994 to October 2014. Some comparisons with Caucasian setting were made when relevant.

RESULTS

From 152 publications selected for this narrative review, differences in foetal growth and birth weight were deducted between Asian and Caucasian children. Infants in India and Hong Kong had increased fat mass at birth and early infancy as compared to those from other parts of the world. Pre- and during pregnancy conditions influenced birth weight; feeding practices and gender influenced post-natal growth and body composition development. High and low birth weights followed by rapid postnatal growth were linked to increased risks of obesity, insulin resistance and high blood pressure in later life.

CONCLUSION

Foetal and postnatal growth trajectories are different between countries within and outside Asia. Extremes in birth weight followed by rapid postnatal growth were linked to increased risks of metabolic health of children in this region. As there is limited evidence in Asia, it is important to conduct thorough investigations by using longitudinal studies on early life programming.

Comparison of methods to measure body fat in 7-to-10-year-old children: a systematic review

OBJECTIVE

To investigate methodological aspects in body fat (BF) measurements in 7-to-10-year-old children.

STUDY DESIGN

Systematic review of the literature.

METHODS

The studies were chosen from the PubMed and Scielo databases according to a protocol that defined: inclusion criteria; a search and quality-assessment strategy; and information extraction.

RESULTS

27 studies published from 2004 to 2014 were included. The literature describes skinfold measurements and dual energy X-ray absorptiometry (DEXA) as being the reference methods most widely used in the assessment of the ability of methods to identify BF. The most commonly-used statistical analyses were the Pearson correlation coefficient, and sensitivity and specificity performance analyses. The comparison between the tested methods and the references showed that body mass index (BMI) and waist circumference (WC) are strongly correlated to BF as calculated by bioelectrical impedance or skinfolds, and that there is a moderate positive correlation with percent body fat as calculated by DEXA, air-displacement plethysmography (ADP) or isotope dilution. There was a moderate positive correlation between waist-to-height ratio (WHtR) and BF, as estimated by ADP and skinfolds. Performance studies suggest that BMI and WC are very specific but less sensitive methods.

CONCLUSIONS

The results of this systematic review show favourable evidence for the use of anthropometric indicators - above all BMI and WC- in the measurement of BF, when more accurate techniques such as DEXA and ADP are not feasible. They also demonstrate features that make them advantageous for epidemiological studies in a child population, since they are easy and safe to obtain and well tolerated by the children.

Linear Growth and Fat and Lean Tissue Gain during Childhood: Associations with Cardiometabolic and Cognitive Outcomes in Adolescent Indian Children

Background

We aimed to determine how linear growth and fat and lean tissue gain during discrete age periods from birth to adolescence are related to adolescent cardiometabolic risk factors and cognitive ability.

Methods

Adolescents born to mothers with normal glucose tolerance during pregnancy from an Indian birth cohort (N = 486, age 13.5 years) had detailed anthropometry and measurements of body fat (fat%), fasting plasma glucose, insulin and lipid concentrations, blood pressure and cognitive function. Insulin resistance (HOMA-IR) was calculated. These outcomes were examined in relation to birth measurements and statistically independent measures (conditional SD scores) representing linear growth, and fat and lean tissue gain during birth-1, 1–2, 2–5, 5–9.5 and 9.5–13.5 years in 414 of the children with measurements at all these ages.

Results

Birth length and linear growth at all ages were positively associated with current height. Fat gain, particularly during 5–9.5 years was positively associated with fat% at 13.5 years (0.44 SD per SD [99.9% confidence interval: 0.29,0.58]). Greater fat gain during mid-late childhood was associated with higher systolic blood pressure (5–9.5 years: 0.23 SD per SD [0.07,0.40]) and HOMA-IR (5–9.5 years: 0.24 [0.08,0.40], 9.5–13.5 years: 0.22 [0.06,0.38]). Greater infant growth (up to age 2 years) in linear, fat or lean components was unrelated to cardiometabolic risk factors or cognitive function.

Conclusion

This study suggests that factors that increase linear, fat and lean growth in infancy have no adverse cardiometabolic effects in this population. Factors that increase fat gain in mid-late childhood may increase cardiometabolic risk, without any benefit to cognitive abilities.

Body composition in Nepalese children using isotope dilution: the production of ethnic-specific calibration equations and an exploration of methodological issues

Background. Body composition is important as a marker of both current and future health. Bioelectrical impedance (BIA) is a simple and accurate method for estimating body composition, but requires population-specific calibration equations.

Objectives. (1) To generate population specific calibration equations to predict lean mass (LM) from BIA in Nepalese children aged 7–9 years. (2) To explore methodological changes that may extend the range and improve accuracy.

Methods. BIA measurements were obtained from 102 Nepalese children (52 girls) using the Tanita BC-418. Isotope dilution with deuterium oxide was used to measure total body water and to estimate LM. Prediction equations for estimating LM from BIA data were developed using linear regression, and estimates were compared with those obtained from the Tanita system. We assessed the effects of flexing the arms of children to extend the range of coverage towards lower weights. We also estimated potential error if the number of children included in the study was reduced.

Findings. Prediction equations were generated, incorporating height, impedance index, weight and sex as predictors (R² 93%). The Tanita system tended to under-estimate LM, with a mean error of 2.2%, but extending up to 25.8%. Flexing the arms to 90° increased the lower weight range, but produced a small error that was not significant when applied to children <16 kg (p 0.42). Reducing the number of children increased the error at the tails of the weight distribution.

Conclusions. Population-specific isotope calibration of BIA for Nepalese children has high accuracy. Arm position is important and can be used to extend the range of low weight covered. Smaller samples reduce resource requirements, but leads to large errors at the tails of the weight distribution.

Analysis of body composition among children and adolescents - a cross-sectional study of the Polish population and comparison of body fat measurement methods

OBJECTIVE

The first aim of the present study was to analyze the body composition of Polish children ages 7-17 years old to add to the current body of literature. The second aim was to compare two body fat measurement methods (bioimpedance vs. Slaughter equation) on the abovementioned population.

METHODS

Height (cm) and weight (kg) of 308 (161 males and 147 females) participants, ages 7-17, were measured, and body mass index (BMI) scores were calculated. Skinfold thickness (SFT) was measured for the triceps, subscapular, abdominal, suprailiac, thigh, and medial thigh skin folds on the left side of the body. Fat mass, fat percentage in the whole body (%BF), fat-free mass, and total body water were assessed using bioelectrical impedance analysis (BIA).

RESULTS

In the present sample, 29.5% of males were overweight, and 11.3% of these were obese. Among females, 27.2% were classified as overweight, and 6.8% of these were obese. Males had a higher total body water (median=27.25 vs. 24.8 kg, p<0.001) and fat-free mass (median=37.25 vs. 33.90 kg, p<0.001), while females showed a higher total body fat percentage (median=22 vs. 14.55%, p<0.001) and fat mass (median=9.1 vs. 5.9 kg, p<0.001). %BF calculated using Slaughter equations overestimated those obtained by BIA in both genders (p<0.0001).

CONCLUSIONS

The percent of youths classified as overweight and obese has increased in Krakow (Poland). Calculation of body fat percent derived from bioimpedance provides better estimates than the use of Slaughter equations, which tended to overestimates the values.

Effect of hyperglycaemia in pregnancy on adiposity in their infants in India: a protocol of a multicentre cohort study

INTRODUCTION

The carbohydrate 'fuel' metabolism in a pregnant woman may have a long-term impact on the development of her offspring ('fuel-mediated teratogenesis' hypothesis) including in utero exposure to maternal hyperglycaemia leading to fetal hyperinsulinaemia, and the consequent increase in fetal fat cells. Therefore, a feed-forward loop can exist of rising adiposity and hyperinsulinaemia throughout childhood, perhaps leading to obesity and diabetes in later life. There is a need for prospective examination of body fat distribution in children born to mothers with different glycaemic levels to understand the plausible association between glucose metabolism and future risk of diabetes in offspring. The hypothesis is that maternal glucose levels in pregnant women are related to skinfold thickness in their infants.

METHODS AND ANALYSIS

Hyperglycaemia in pregnancy and adiposity in infants is a multicentre cohort study to evaluate the effects of glucose levels in pregnancy on the risk of adverse infant outcomes, especially in predicting the risk of chronic diseases in infants. The study aims to recruit 1045 participants over a period of 1 year, who will be followed up irrespective of their glycaemia status for a period of 15 months, beginning in the 24th week of gestation. The glucose levels in pregnant women would be obtained through oral glucose tolerance testing. The primary outcome of our study was skinfold thickness in infants at the age of 6 weeks, 3rd and 9th month (as a proxy for fat distribution/adiposity).

ETHICS AND DISSEMINATION

The institutional review board at The Indian Institute of Public Health (IIPH)-Hyderabad, Public Health Foundation of India has approved the protocol. All participants are required to provide written informed consent.

Association of Metabolic Syndrome with Body Fat Percent, Anthropometric Indices in 10 To 18 Year Old Adolescents

BACKGROUND

Our aim was to evaluate the association of metabolic syndrome (MetS) and its components with body fat percentage (BFP) and anthropometric indicesin10 to 18year old adolescents.

METHODS

This was a cross-sectional study conducted on 134 Tehranian adolescents, aged 10 to 18 years (66 boys and 68 girls) in 2007. The MetS definition proposed by Cook et al. was used. Logistic regression was used to determine the relationship of MetS and its components with body mass index (BMI), waist circumference (WC), waist to height ratio (WHtR), and BFP. Using the areas under the receiver operating characteristic (ROC) curve, the discriminatory ability of anthropometric measurements and BFP was evaluated.

RESULTS

The mean±SD forage of boys and girls was14.5±2.3and13.0±2.9 years, respectively (P=0.001); the prevalence of MetS in these groups was 32.3 and6.5%, respectively (P=0.001). After adjusting for sex and physical activity, the highest odds ratios (95% CI) for MetS and hypertriglyceridemia were found for WC, 6.27 (2.63-14.94; P<0.05)and 3.14 (1.87-5.27; P<0.05), respectively, and those for low HDL-C and hypertension were found for BMI, 2.91 (1.73-4.90; P<0.05)and 2.26 (1.27-4.02; P=0.05), respectively. After adjusting for sex and physical activity, the highest area under ROC curve for MetS and hypertriglyceridemia was seen for WC (P=0.001), for hypertension it was seen for BMI (P=0.001), and for low HDL-C it was observed for both WC and BMI (P=0.001).

CONCLUSIONS

In adolescents, WC was the best predictor of MetS and hypertriglyceridemia, BMI was the best predictor of hypertension, and WC and BMI were the best predictors for low HDL-C.

Bioelectrical impedance analysis to estimate body composition in children and adolescents: a systematic review and evidence appraisal of validity, responsiveness, reliability and measurement error

Bioelectrical impedance analysis (BIA) is a practical method to estimate percentage body fat (%BF). In this systematic review, we aimed to assess validity, responsiveness, reliability and measurement error of BIA methods in estimating %BF in children and adolescents.We searched for relevant studies in Pubmed, Embase and Cochrane through November 2012. Two reviewers independently screened titles and abstracts for inclusion, extracted data and rated methodological quality of the included studies. We performed a best evidence synthesis to synthesize the results, thereby excluding studies of poor quality. We included 50 published studies. Mean differences between BIA and reference methods (gold standard [criterion validity] and convergent measures of body composition [convergent validity]) were considerable and ranged from negative to positive values, resulting in conflicting evidence for criterion validity. We found strong evidence for a good reliability, i.e. (intra-class) correlations ≥0.82. However, test-retest mean differences ranged from 7.5% to 13.4% of total %BF in the included study samples, indicating considerable measurement error. Our systematic review suggests that BIA is a practical method to estimate %BF in children and adolescents. However, validity and measurement error are not satisfactory.

The association between growth response to growth hormone and baseline body composition of children with growth hormone deficiency

OBJECTIVE

We wanted to examine the relationship between initial growth response to recombinant human Growth Hormone (rhGH) treatment and body composition in children with growth hormone deficiency (GHD).

DESIGN AND METHODS

Forty-two patients (21 boys and 21 girls) aged between 5.7-15.5 years (mean age: 10.8 ± 2.6 years) with isolated GHD. The auxological and laboratory data (GH and IGF-I levels) and results of bioelectrical impedance analyses were evaluated. Children with GHD were followed up for 12 months and categorized according to growth response to rhGH into good and poor responders (change in height of > 0.7 SDS or < 0.7 SDS over one year respectively). Mean doses of rhGH per kg of fat free mass (FFM) were calculated.

RESULTS

Forty-eight percent of patients showed a good growth response to rhGH therapy. At study entry, mean age, height SDS, weight SDS, serum IGF-1 SDS, IGFBP-3 SDS, growth velocity prior to rhGH therapy, GH after clonidine and l-dopa were similar in the two groups. At baseline, BMI SDS and waist-hip ratio were significantly higher in good responders (p = 0.02 and p = 0.006, respectively). Good responders had lower percentages of FFM (73.4 ± 8.9 vs. 83.1 ± 5.9) and total body water (TBW) (56.5 ± 5.3 vs. 63.1 ± 4.4), compared to poor responders (p < 0.05). There were significant correlations between changes in height SDS over one year and baseline body composition in children with GHD on rhGH treatment (r = -0.617 for percentage of FFM, r = -0.629 for percentage of TBW, p < 0.001). A correlation between BMI SDS, waist-hip ratio, mean rhGH dose per FFM and growth response was observed only in prepubertal subjects.

CONCLUSION

Baseline body composition data in children with GHD can be used to predict the growth response to rhGH treatment. A management strategy that involves titrating rhGH dose according to FFM as a means of optimizing the growth response to intervention requires further study.

Body fat in Singaporean infants: development of body fat prediction equations in Asian newborns

BACKGROUND/OBJECTIVES

Prediction equations are commonly used to estimate body fat from anthropometric measurements, but are population specific. We aimed to establish and validate a body composition prediction formula for Asian newborns, and compared the performance of this formula with that of a published equation.

SUBJECTS/METHODS

Among 262 neonates (174 from day 0, 88 from days 1-3 post delivery) from a prospective cohort study, body composition was measured using air-displacement plethysmography (PEA POD), with standard anthropometric measurements, including triceps and subscapular skinfolds. Using fat mass measurement by PEA POD as a reference, stepwise linear regression was utilized to develop a prediction equation in a randomly selected subgroup of 62 infants measured on days 1-3, which was then validated in another subgroup of 200 infants measured on days 0-3.

RESULTS

Regression analyses revealed subscapular skinfolds, weight, gender and gestational age were significant predictors of neonatal fat mass, explaining 81.1% of the variance, but not triceps skinfold or ethnicity. By Bland-Altman analyses, our prediction equation revealed a non-significant bias with limits of agreement (LOA) similar to those of a published equation for infants measured on days 1-3 (95% LOA: (-0.25, 0.26) kg vs (-0.23, 0.21) kg) and on day 0 (95% LOA: (-0.19, 0.17) kg vs (-0.17, 0.18) kg). The published equation, however, exhibited a systematic bias in our sample.

CONCLUSIONS

Our equation requires only one skinfold site measurement, which can significantly reduce time and effort. It does not require the input of ethnicity and, thus, aid its application to other Asian neonatal populations.

Cardiometabolic risk markers in Indian children: comparison with UK Indian and white European children

OBJECTIVE

UK Indian adults have higher risks of coronary heart disease and type 2 diabetes than Indian and UK European adults. With growing evidence that these diseases originate in early life, we compared cardiometabolic risk markers in Indian, UK Indian and white European children.

METHODS

Comparisons were based on the Mysore Parthenon Birth Cohort Study (MPBCS), India and the Child Heart Health Study in England (CHASE), which studied 9-10 year-old children (538 Indian, 483 UK Indian, 1375 white European) using similar methods. Analyses adjusted for study differences in age and sex.

RESULTS

Compared with Mysore Indians, UK Indians had markedly higher BMI (% difference 21%, 95%CI 18 to 24%), skinfold thickness (% difference 34%, 95%CI 26 to 42%), LDL-cholesterol (mean difference 0.48, 95%CI 0.38 to 0.57 mmol/L), systolic BP (mean difference 10.3, 95% CI 8.9 to 11.8 mmHg) and fasting insulin (% difference 145%, 95%CI 124 to 168%). These differences (similar in both sexes and little affected by adiposity adjustment) were larger than those between UK Indians and white Europeans. Compared with white Europeans, UK Indians had higher skinfold thickness (% difference 6.0%, 95%CI 1.5 to 10.7%), fasting insulin (% difference 31%, 95%CI 22 to 40%), triglyceride (% difference 13%, 95%CI 8 to 18%) and LDL-cholesterol (mean difference 0.12 mmol/L, 95%CI 0.04 to 0.19 mmol/L).

CONCLUSIONS

UK Indian children have an adverse cardiometabolic risk profile, especially compared to Indian children. These differences, not simply reflecting greater adiposity, emphasize the need for prevention strategies starting in childhood or earlier.