Comparison of Body Composition Assessed by Multi-Frequency Segmental Bioelectrical Impedance Analysis and Dual Energy X-Ray Absorptiometry in Hemodialysis Patients

Background: The assessment of body composition during the course of treatment of hemodialysis patients is crucial for optimal treatment. We intended to assess the diagnostic performance of bioelectrical impedance analysis (BIA), which could be used at the bedside in dialysis wards, and compare it with the results of dual-energy X-ray absorptiometry (DEXA). Methods: In a cross-sectional study, 43 patients with end-stage renal disease (ESRD) after hemodialysis sessions underwent direct segmental multi-frequency BIA. Volume status and body composition indices with eight electrodes connected to four limbs were measured at 1, 5, 50, 250, 500, and 1000 kHz frequencies. Then, the patients were sent to the nuclear ward for the corresponding assessments by DEXA. The results of the two methods were compared by a paired t-test and the correlations were assessed using general linear models and regression analyses. For the assessment of agreements, Bald-Altman plots were used. Results: The whole body values for bone, fat, and lean body mass were different between BIA (3.4, 22, and 44.5 kg, respectively) and DEXA (1.5, 28.5, and 40.4 kg, respectively). However, the results were strongly linearly correlated even after adjustment for age and sex (r = 0.67, P = 0.001 for bone mass; r = 0.93, P = 0.001 for fat mass; and r = 0.96, P = 0.001 for lean body mass). The same strong correlation was found for the segmental values. Conclusions: The results of BIA and DEXA are correlated strongly and are interchangeable. As the BIA is more easily available and less expensive, the routine use of BIA at hemodialysis departments is reasonable.