Background: Accurate measurement of human body composition is important in diagnosing obesity. Dual Energy X-ray Absorptiometry (DEXA) has been known as gold standard for both clinical and research purposes. Also, Bioimpedance Analysis (BIA) is also inexpensive, portable, and easy to measure body composition. The aim of this study is to compare the measurements of lean body mass and fat mass taken by DEXA and BIA using Bland-Altman Plot Analysis.
Methods: We recruited 57 obese subjects (9 males, 48 females; ages 21~45 years) who visited obesity clinic. Body fat mass (kg) and lean body mass (kg) were measured respectively by BIA and DEXA. Then, correlation was assessed by using Bland-Altman plot analysis.
Results: Mean BMI was 29.0 ± 4.4 kg/m2. Correlation between free fat mass and measured fat mass by DEXA and BIA was highly significant according to BMI group ( P < 0.001). Bland-Altman plot shows good agreement between free fat mass and fat mass measured by DEXA and BIA.
Conclusion: BIA could be useful method in measurement of body composition compared to DEXA.

Keywords: Body composition, Obesity, Dual energy X-ray absorptiometry, Bioelectrical impedance analysis, Bland-Altman plot analysis.