Evaluating the Accuracy and Clinical Utility of Bioelectrical Impedance Analysis (BIA) Devices for Body Composition Measurements in Clinical Practice: Comparison of Four Types of BIA Equipment and Dual-Energy X-ray Absorptiometry

Background: This study aimed to evaluate whether Bioelectrical Impedance Analysis (BIA) can serve as a practical alternative to Dual- Energy X-ray Absorptiometry (DEXA) for measuring body composition in clinical settings.Methods: BIA (InBody970, InBody770, InBody770C, and InBody270C) and DEXA were repeatedly used for measurements on the same day (n=100). Participants fasted for at least 4 hours and stood upright for 10 minutes before the measurements to stabilize body water composition.Results: All four BIA devices (InBody970, InBody770, InBody770C, and InBody270C) showed a high correlation with DEXA, with Pearson correlation coefficients (r) of ≥0.97 for both muscle mass and body fat mass. Among them, the InBody770C demonstrated a slightly higher correlation in body fat mass measurements (P<0.05). However, Lin’s Concordance Correlation Coefficient ranged from 0.939 to 0.941, indicating only moderate agreement. In addition, Bland–Altman analysis revealed statistically significant mean biases and wide limits of agreement across all devices, suggesting that strong correlation does not necessarily imply measurement equivalence.Conclusions: Given the high correlation between BIA and DEXA, BIA may serve as a useful tool for tracking body composition. However, moderate agreement levels suggest that caution is warranted when interpreting BIA as a substitute for DEXA in clinical practice.