Four-compartment model and validation of deuterium dilution technique to estimate fat-free mass in Mexican youth

Nutrition and Health in Arab Adolescents (NaHAR): Study protocol for the determination of ethnic-specific body fat and anthropometric cut-offs to identify metabolic syndrome

The prevalence of adolescent obesity in the Middle-East is considered among the highest in the world. Obesity in adolescents is associated with several cardiometabolic abnormalities, the constellation of which is referred to as the metabolic syndrome (MetS). This multi-country cross-sectional study aims to determine the optimal cut-off values for body fat (BF); body mass index (BMI) z-score; waist circumference (WC) percentile, and mid-upper arm circumference (MUAC) for the prediction of MetS among adolescents from Kingdom of Saudi-Arabia (KSA), Kuwait, Jordan, Lebanon and Syria. A secondary objective is to examine the validity of Bioelectrical Impendence Vector Analysis (BIVA) in estimating BF against the deuterium dilution technique (DDL). In each country, a sample of 210 adolescents will be recruited. Data collection will include demographics, socioeconomic, lifestyle and dietary data using a multi-component questionnaire; anthropometric measurements will be obtained and body composition will be assessed using the DDL and BIVA; blood pressure and biochemical assessment will be performed for the identification of the MetS. Receiver operating characteristic analyses will be undertaken to determine optimal cut-off values of BMI, WC, MUAC and BF in identifying those with MetS. Odds ratios (OR) and their respective 95% confidence interval (CI) for the association of the anthropometric measurements with MetS will be computed based on multiple logistic regression analysis models. The Bland and Altman approach will be adopted to compare BIVA against the reference DDL method for the determination of body composition parameters. This study responds to the need for ethnic-specific anthropometric cut-offs for the identification of excess adiposity and associated cardiometabolic risks in the adolescent population. The adoption of the generated cut-offs may assist policy makers, public health professionals and clinical practitioners in providing ethnic-specific preventive and curative strategies tailored to adolescents in the region.

Anthropometry-Based Prediction Equation of Body Composition in a Population Aged 12-88 Years

BACKGROUND

Direct anthropometric measurements to assess body composition have limited precision and/or specificity.

OBJECTIVES

The study aimed to develop a prediction equation based on anthropometric measurements for estimating total body water (TBW) in a healthy population.

METHODS

TBW was assessed using the deuterium dilution method in 398 Moroccan participants (235 women and 163 men) aged 11.6-88 y, then compared to the estimations made by previously published anthropometric equations. By sex, participants were randomly assigned into development (n = 199) and validation subgroups (n = 199). A new anthropometric equation was developed in the development subgroup from data obtained on body volume (BV), weight, and sex, where the BV was calculated from participants' height. Then the equation was validated in the validation subgroup using the Bland and Altman procedure, bias, and pure error. External validation was performed using a sample from Tunisia (n = 220, 51.8% female, 18-65 y).

RESULTS

Bias in predicting TBW showed unacceptable value for all previously published equations as it was significantly overestimated. The following new equation using anthropometric measurements [TBW (kg) = -5.249 + 107.502 BV (L) + 0.289 weight (kg) + 2.015 sex (male: 1, female: 0); (R² = 0.91, RMSE = 1.885 kg)] was developed, and its internal validation was confirmed. The generated bias and pure error values were 0.047 kg (95% CI: -0.235, 0.330) and 2.02 kg (95% CI: 1.73, 2.31), respectively. The external validation of the new TBW prediction equation on a Tunisian sample showed a bias and pure error values of 0.07 kg (95% CI: -0.289, 0.429) and 2.36 kg, respectively.

CONCLUSIONS

The results indicate that the new anthropometric-based prediction equation provides a good estimation of TBW and other body composition compartments. It could be recommended as an alternative method to assess body composition for epidemiological and clinical studies.

Body Composition in Youths Aged 10‒17 Years by Deuterium Oxide Dilution, Air Displacement Plethysmography, and DXA: Validation of the Medical Body Composition Analyzer Bioimpedance Device by a 4-Compartment Model

BACKGROUND

The medical body composition analyzer (mBCA) incorporates advances in multifrequency technology and has been validated using a 4-compartment (4C) model in adults but not in youths aged <18 y.

OBJECTIVES

This study aimed to formulate a 4C model based on 3 reference methods and develop and validate a body composition prediction equation for the mBCA in youths aged 10‒17 y.

METHODS

The body density of 60 female and male youths was measured by air displacement plethysmography, total body water by deuterium oxide dilution, and BMC by DXA. Data from the equation group (n = 30) were used to formulate a 4C model. The all-possible-regressions method was used to select variables. The model was validated in a second cohort (n = 30) in a random split design. The accuracy, precision, and potential bias were evaluated by the Bland and Altman procedure.

RESULTS

Mean age, weight (W), height (H), waist circumference, and z-score of BMI were 13.6 ± 2.3 y, 54.5 ± 15.5 kg, 156 ± 11.9 cm, 75.5 ± 10.9 cm, and 0.70 ± 1.32 z, respectively. The prediction equation was as follows: FFM in kg (FFM_kg) = ([0.2081] ∗ [W] + [0.8814] ∗ [H²_cm/R_Ω] + [0.2055 ∗ Xc_Ω])-15.343; R² = 0.96; standardized root-mean-square error (SRMSE) = 2.18 kg. FFM did not differ between the 4C method (38.9 ± 12.0 kg) and the mBCA (38.4 ± 11.4 kg) (P > 0.05). The relationship between these 2 variables did not deviate from the identity line, was not significantly different from 0, and the slope was not significantly different from 1.0. In the precision prediction model of mBCA, the R² value was 0.98 and SRMSE was 2.1. No significant bias was found when regressing differences between methods and their means (P = 0.08).

CONCLUSIONS

The equation for the mBCA was accurate, precise, had no significant bias, had substantial strength of agreement and could be used in this age group when subjects were preferentially within the constraints of a specified body size.

Development of bioelectrical impedance-based equations for the prediction of body composition of Malawian adolescents aged 10-18 years: a cross-sectional study

OBJECTIVES

The accuracy of bioelectrical impedance analysis (BIA) depends on population-specific prediction equations and there is no population-specific equation for predicting fat-free mass (FFM) in Malawian adolescents. This study aimed at determining the agreement between FFM measured by deuterium oxide dilution technique (the reference) and FFM by BIA; and propose BIA-based prediction equations to estimate FFM for Malawian adolescents.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted in Blantyre, Malawi PARTICIPANTS: 186 Malawian adolescents aged between 10 and 18 years were included in this study. Body composition was estimated by both the BodyStat BIA analyser and the deuterium oxide dilution method.

RESULTS

BIA inbuilt equation underestimated FFM compared with deuterium oxide dilution (p=0.039). The new prediction equation for FFM (kg)=-4.316+ 0.425* height²(cm)/resistance (Ω)+1.287* sex (male=1, female=0)+0.307*age(years)+0.344* weight(kg)+0.019*reactance(Ω) yielded an R2 of 0.926. The equation for total body water (TBW) (kg)=-2.152 + 0.328*height²(cm)/resistance (Ω) 0.910*sex (male=1, female=0)+0.307 *age (years)+0.249*weight(kg)+0.015*reactance(Ω) yielded an R2 of 0.922. The Bland-Altman plot illustrated a good level of concordance between the FFM and TBW predicted by the new equations and the values derived using deuterium dilution method.

CONCLUSIONS

The new BIA prediction equations for estimating FFM and TBW could be used to assess with very good accuracy and precision the body composition of Malawian and adolescents with similar characteristics.

Relevance of body mass index and bioelectrical impedance analysis vs. deuterium dilution technique to assess excess of fat among young adults

Our study aimed to assess the nutritional status by using body composition among young Tunisian adults through three measurement methods: body mass index (BMI), bioelectrical impedance analysis (BIA) and deuterium oxide dilution technique (²H₂O) and to determine the accuracy of BMI and BIA in order to evaluate the overweight and obesity among young adults in Tunisia. Our study involved 144 young adults. Anthropometric parameters were measured. The fat mass percentage (%FM) was determined by ²H₂O and BIA techniques. The analysis of deuterium enrichment was performed using a Fourier transform infrared spectrophotometer (FTIR). According to BMI, 26.4% of subjects were overweight and 5.5% were obese. The mean of %FM estimated by BIA was significantly higher than that determined by ²H₂O (29.7 ± 7.7 vs. 26.3 ± 10.6, p < .0001). Consequently, the prevalence of overweight and obesity assessed by BIA was significantly higher than by ²H₂O (51.4% vs. 34%, p < .0001). Using BMI, the prevalence of overweight and obesity was similar to that estimated by ²H₂O (31.9% vs. 34%, p = 0.544). Compared to ²H₂O, BIA overestimates the prevalence of overweight and obesity in young adults. On the other hand, the BMI showed an interesting correlation with the %FM determined by ²H₂O.

Overweight and Obesity, Cardiometabolic Health, and Body Composition: Findings From the Follow-Up Studies of the INCAP Longitudinal Study

BACKGROUND

There has been increased interest in the hypothesis that undernutrition in early life predisposes to cardiometabolic disease risk in adulthood. The Institute of Nutrition of Central America and Panama Longitudinal Study is able to address one critical aspect of this field, specifically whether improvements in nutrition can prevent this increased risk.

OBJECTIVE

To describe the main findings on obesity and body composition across 5 waves of field work (1988-1989, 1991-1994, 1998-1999, 2002-2004, and 2015-2017) and on cardiometabolic health across 3 waves (1998-1999, 2002-2004, and 2015-2017).

RESULTS

Body weight and body fat increased considerably in adulthood, especially among women with sedentary occupations. Adiposity and weight in adulthood were strongly predicted by weight gain after the first 1000 days of life. On the other hand, exposure to improved nutrition in early life reduced diabetes risk by approximately 50% but increased the risk of overweight and obesity.

CONCLUSIONS

Future research will aid in clarifying the underlying mechanisms that drive the opposite associations among diabetes and obesity with early-life nutrition.

Measuring growth and medium- and longer-term outcomes in malnourished children

Severe and moderate acute malnutrition are among the leading causes of mortality among children in low- and middle-income countries. There is strong evidence that growth assessed anthropometrically from conception to 2 years of age marks later risk of ill health. This is central to the concept of the developmental origins of adult disease and is presumed to be related to modification of developmental processes during critical "window(s)" of vulnerability. Interventions to treat acute malnutrition have resulted in dramatic increase in the number of affected children surviving. Ensuring that these children thrive to fulfil their full physical and cognitive potential is a new challenge. Integral to this challenge is the need to be able to measure how earlier insults relate to the ability to survive and thrive to productive adulthood. Despite its obvious value, routine anthropometry does not adequately indicate how earlier adverse exposures affect more refined aspects of growth. Anthropometry is inadequate for predicting how disruption of healthy growth might modulate risk of disease or any subsequent interventions that correct this risk. A clear characterisation of healthy child growth is needed for determining which component best predicts later outcomes. The extent to which postnatal acute malnutrition is a consequence of maternal factors acting preconception or in utero and their relationship to postnatal health and long-term risk of non-communicable diseases is not clear. Body-composition measurement has significant untapped potential allowing us to translate and better understand the relationship between early insults and interventions on early growth in the short-term and long-term health outcomes.

Proposal of new body composition prediction equations from bioelectrical impedance for Indonesian men

BACKGROUND/OBJECTIVES

Bioelectrical impedance analysis (BIA) is one of the most affordable and feasible body composition assessment techniques for clinical and field settings. However, it is important to use an equation appropriate for the study population. This study aimed to propose and validate prediction equations to estimate body composition using BIA for Indonesian men.

SUBJECTS/METHODS

Total body water (TBW), fat-free mass (FFM) and fat mass (FM) were determined using the deuterium dilution technique in 292 Indonesian males. Participants were divided equally into development and validation groups to develop prediction equations and to cross-validate the proposed prediction equations, respectively. In addition, selected prediction equations using BIA were cross-validated.

RESULTS

The proposed BIA equations were valid in our cross-validation samples. The best performance equations obtained from the absolute measure of body composition (TBW, FFM and FM) showed that r ranged between 0.89 and 0.91 and standard error of the estimate=1.8-2.6 kg. Cross-validation analysis indicated that the proposed equations had a bias of 0.1-0.3 kg, pure error of 1.3-1.8 kg and limits of agreement (mean difference±1.96 s.d.) of -0.26 to 0.13±4.09 to 5.59 kg. Among existing prediction equations examined, those by Deurenberg et al. (1989) and Lukaski et al. (1987) significantly overestimated FM by 4.0 and 3.2 kg, respectively, whereas the equation by Deurenberg et al. (1991) significantly (P<0.001) underestimated FFM by 5.0 kg compared with the reference FFM.

CONCLUSIONS

The new BIA prediction equations may provide more precise and accurate estimation of body composition in Indonesian men than the existing equations.

The four-compartment model of body composition in obese Chilean schoolchildren, by pubertal stage: comparison with simpler models

OBJECTIVES

We assessed the agreement of body fat and fat-free mass measured by simpler methods against the four-compartment model (4C).

METHODS

In 60 obese schoolchildren (body mass index ≥95th percentile) between the ages of 8 and 13 y who were recruited from one school in Chile, multicompartmental body composition was estimated with the use of isotopic dilution, plethysmography (BodPod), radiographic absorptiometry (DEXA), and anthropometric equations. These results were compared to those of the 4C model, which is considered the gold standard.

RESULTS

For body fat, the 4C model showed the best agreement with DEXA for boys in Tanner stages I and II (r = 0.971) and with isotopic dilution for boys in Tanner stages III and IV (r = 0.984). The best agreement in girls occurred with isotopic dilution, regardless of pubertal stage (r = 0.948 for Tanner stages I and II; r = 0.978 for Tanner stages III and IV). Both isotopic dilution and the Huang, Ellis, and Deurenberg anthropometric equations underestimated body fat in boys; by contrast, DEXA, BodPod, and the Slaughter equation overestimated body fat in boys. All of the equations underestimated body fat in girls. For fat-free mass in both boys and girls, the 4C model showed the best agreement with isotopic dilution, regardless of pubertal stage. The Huang equation showed the best agreement for boys (r = 0.730 for Tanner stages I and II; r = 0.695 for Tanner stages III and IV) and for girls in Tanner stages I and II (r = 0.884). The Ellis equation had the best agreement for girls in Tanner stages III and IV (r = 0.917).

CONCLUSIONS

For obese Chilean children of both sexes, isotopic dilution and DEXA were the two-compartment methods that had the best agreement with the gold-standard 4C model for both body fat and fat-free mass; these were followed by the Huang and Ellis anthropometric equations.

Validity of the methods to assess body fat in children and adolescents using multi-compartment models as the reference method: a systematic review

OBJECTIVE

To analyze the validity of methods to assess body fat in children and adolescents using a systematic review.

METHODS

The search was conducted by two independent researchers using the MEDLINE, BioMed Central, SciELO and LILACS electronic databases. For inclusion, the articles should be written in English or Portuguese, and must have used multi-compartment models as the criterion measure of the model, with body fat measurement of whole body in non-athlete children and adolescents.

RESULTS

A preliminary search resulted in 832 studies. After all selection steps were performed, 12 articles were included. The selected studies were published between 1997 and 2010, whose samples consisted of children and adolescents with levels of relative body fat ranging from 20.7% to 41.4%. The methods used were: dual energy X-ray absorptiometry (58.3%), isotope dilution (41.6%), skinfold thickness (33.3%), hydrostatic weighing (25%), bioelectrical impedance analysis (25%), air displacement plethysmography (16.6%), and total body electrical conductivity (8.3%).

CONCLUSIONS

Based on the analysis of the studies, isotope dilution and air displacement plethysmography methods were the most reliable, despite the limited number of studies. As for clinical use or for population-based studies, the equation of Slaughter et al. (1998), which uses the triceps and subscapular skinfolds thickness, showed the best results for assessment of body fat in this population.