The comparative evaluation of patients' body dry weight under hemodialysis using two methods: Bioelectrical impedance analysis and conventional method

Background: Dry weight (DW) is an important concept related to patients undergoing hemodialysis. Conventional method seems to be time consuming and operator dependent. Bio impedance analysis (BIA) is a new and simple method reported to be an accurate way for estimating DW. In this study, we aimed to compare the conventional estimation of DW with measuring DW by BIA. Materials and Methods: This study involved 130 uremic patients, performed in Isfahan, Iran. DW was calculated by both conventional (CDW) and BIA (BIADW) method and results were compared based on different grouping factors including sex, underlying cause of renal failure (RF) (diabetic RF and non-diabetic RF), body mass index (BMI) status, and sessions of hemodialysis. We also calculated the difference between DWs of 2 methods (DW diff = CDW-BIADW). Results: The mean of BIADW was significantly lower than CDW (57.20 +/- 1.82 vs 59.36 +/- 1.77, P value < 0.001). After grouping cases according to the underlying cause, BMI, sex, and dialysis sessions BIADW was significantly lower than CDW. Conclusion: Based on the combination of problems with CDW measurement which are corrected by BIA, and more clinical reliability of CDW, we concluded that although conventional method is a time-consuming and operator-dependent way to assess DW, DW could be estimated by combining both of these methods by finding the mathematic correlation between these methods.