Performance of bioelectrical impedance analysis compared to dual X-ray absorptiometry (DXA) in Veterans with COPD

We examined the performance of a commercially-available handheld bioimpedance (BIA) device relative to dual X-ray absorptiometry (DXA) to assess body composition differences among Veterans with chronic obstructive pulmonary disease (COPD). Body composition was measured using DXA and BIA (Omron HBF-306C) at a single time point. Correlations between BIA- and DXA-assessed percent fat, fat mass, and fat-free mass were analyzed using Spearman (ρ) and Lin Concordance Correlation Coefficients (ρ_c). Mean differences in fat mass were visualized using Bland-Altman plots. Subgroup analyses by obesity status (BMI < 30 versus ≥ 30) were performed. Among 50 participants (96% male; mean age: 69.5 ± 6.0 years), BIA-assessed fat mass was strongly correlated (ρ = 0.94) and demonstrate excellent concordance (ρ_c = 0.95, [95%CI: 0.93-0.98]) with DXA, with a mean difference of 2.7 ± 3.2 kg between BIA and DXA. Although Spearman correlations between BIA- and DXA-assessed percent fat and fat-free mass were strong (ρ = 0.8 and 0.91, respectively), concordance values were only moderate (ρ_c = 0.67 and 0.74, respectively). Significantly stronger correlations were observed for obese relative to non-obese subjects for total percent fat (ρ_obese = 0.85 versus ρ_non-obese = 0.5) and fat mass (ρ_obese = 0.96 versus ρ_non-obese = 0.84). A handheld BIA device demonstrated high concordance with DXA for fat mass and moderate concordance for total percent fat and fat-free mass.ClinicalTrials.gov: NCT02099799.