Agreement and Validity Between 2 Bioimpedance Devices Including Portable Device, DXA, and Isotope Dilution for Estimating Body Composition in Women

Body composition is an important metric for evaluating metabolic health. The InBody (IB) 720 and the portable and more affordable InBody 230 (InBody, Seoul, South Korea) are multi-frequency bioelectrical impedance analysis (BIA) devices used to estimate body composition. The gold standard for estimating lean mass and fat mass is dual-energy X-ray absorption (DXA), and the gold standard for body water is isotope dilution with deuterium oxide (D2O). However, the gold standards are more expensive and require technically-trained personnel. Hence, we set out to see if BIA devices can match the standards. Forty-five women (21.56±2.82 years; BMI 26.71±6.39; 27.6% Caucasian) were evaluated using the IB720, IB230, DXA, and D2O for total body water (TBW), lean body mass (LBM), and total fat mass (TFM). Validity and agreement were determined by correlation statistics and Bland-Altman plots of differences between measures versus mean. Both LBM and TFM were strongly correlated between the BIA devices and DXA, as were TBW measures by D2O and the BIA devices (r\u3e0.90, p2O were in agreement, while LBM and TFM measures by both BIA devices and DXA were not in agreement. Our findings suggest that the IB720 and IB230 can be used in place of D2O method to measure TBW; however, they cannot be used in place of DXA for fat mass and regional lean mass. The IB720 and IB230 were in agreement and can be used interchangeably for TBW and TFM