Validation of Bioelectrical Impedance Analysis in Adolescents Across Different Ethnic Groups

Abstract

Adolescent obesity is difficult to assess in multi‐ethnic populations using BMI, due to variability in the BMI–fatness relationship. We aimed to describe body composition (BC), and to validate leg–leg bioelectrical impedance analysis (BIA), in adolescents from different ethnic groups using deuterium (D2O) as the reference method. Measurements were made of weight, height, total body water (TBW), and BIA (TANITA TBF‐300) in 110 white, 170 Asian, and 102 black adolescents aged 11–15 years. TBW was converted to lean mass (LM) using assumed hydration of lean tissue. General linear models were used to compare BC by D2O between the ethnic groups. BC values from D2O were compared with TANITA values, and used to generate ethnic‐specific prediction equations in the whole sample, and also in equation‐generation (group 1) and cross‐validation (group 2) subsamples. Ethnic variability in BMI did not reflect variability in adiposity. Asians had less LM than white and black adolescents, and less fat mass (FM) than white girls. TANITA in‐built equations did not predict BC accurately across ethnic groups, with significant bias in white and Asian males, and Asian and black females. The new equation generated from the entire sample removes ethnic‐specific mean biases. The group 1 equation showed no significant bias in any ethnic group when tested in group 2. We found significant variability in BC between ethnic groups that was not reflected by BMI. Manufacturers' equations are unsuitable for predicting BC in multi‐ethnic populations, and our new equations are recommended.

Body composition prediction equations based on deuterium oxide dilution method in Mexican children: a national study

“…A recent study reported ethnicity as a predictor of TBW with a leg-to-leg BIA in Caucasian, Asian and Afro-American adolescents. 21 However, most studies have found no significant contribution of ethnicity, despite differences in body composition reported in the samples. 22,23 In a study that included New Zealand European, Maori and Pacific Island children; ethnicity was not selected as a predictor in a BIA equation based on isotopic deuterium dilution.…”

“…We hypothesized that a specific regression equation might reveal with precision whether individuals from different ethnic groups and regions showed differences in the relationship between body size (BMI) and FM or FFM, as has been shown in other countries. 7 Thus, the objective of this study was to develop equations for bioelectrical impedance and anthropometry based on deuterium oxide dilution to assess body composition in Mexican school children from different geographical regions and ethnic groups.…”

Validation of bioelectrical impedance analysis for total body water assessment against the deuterium dilution technique in Asian children

“…The inclusion of ethnicity into the equation improved the estimation of FFM and TBW in Thai children. Some previous studies have shown that ignoring the ethnicity effect would result in underestimation of FFM by 1.6 kg in black girls (Going et al, 2006), 1.8 kg in Maori and Pacific boys and 1.6 kg in Pacific girls (Sluyter et al, 2009) and 1.5 kg in South Asian girls and 1.3 kg in South Asian boys (Haroun et al, 2010). Several factors can explain the ethnic difference in the relationship between BIA impedance/resistance and TBW/FFM.…”

“…Further, some previous studies have assessed whether ethnicity contributes to the relationship between bioimpedance and body composition in adolescents (Going et al, 2006;Sluyter et al, 2009;Haroun et al, 2010) rather than in children. Therefore, the validity of BIA in a multi-ethnic sample of Asian children is unknown.…”

Physical activity patterns of ethnic children from low socio-economic environments within the UK

“…The lack of relationship between moderate to vigorous physical activity in different environments and fatness could be due to a number of reasons. Firstly, fatness differences exist between white and South Asian children (Deurenberg, Chew & Deurenberg, 2002;Nightingale, Rudnicka, Owen, Cook & Whincup, 2011;Saxena, Ambler, Cole & Majeed, 2004) and the existing criteria for determining adiposity is validated in white populations, providing mean bias in ethnic populations (Haroun et al, 2010). The lack of ethnic specific cutoffs thus might make this challenging (Jebb, Cole, Doman, Murgatroyd & Prentice, 2000;Frisard et al, 2005;Sun et al, 2003).…”