Clinical prognostic role of bioimpedance phase angle in diabetic and non-diabetic hemodialysis patients

Background and Objectives: Bioelectrical-impedance analysis (BIA) is frequently used to estimate dry weight in hemodialysis (HD) patients. However, the clinical prognostic significance of BIA indicators is unclear. As a nutritional index, low phase angle (PA) might be an independent risk factor for predicting death in multiple chronic diseases. We performed this study to find relative influence factors of PA and other clinical prognostic significance. Methods and Study Design: The study involved 87 HD patients, 33 of whom were diabetic and 54 of whom were not. We measured body composition index, body water index and nutritional indicators and collected biochemical criteria. Then, we statistically analyzed the associations of these indices. After 1 year of follow- up, we recorded death, heart failure, hospitalization, cerebrovascular and cardiovascular events and other clinical outcomes. Results: We found a significant difference between the two groups in visceral-fat area, extracellular water/total body water (ECW/TBW) ratio and PA value. Two factors were negatively associated with PA: ECW/TBW ratio and HCO3− before HD. At 1 year, we noted that PA was associated with events such as heart failure or hospitalization. By further stratification and multivariate analysis adjusting for age, sex and months of dialysis, we found that low PA was an independent predictor of heart failure for diabetic HD patients. Conclusions: PA value was lower in Diabetic nephropathy (DN) HD patients, than that in non-DN HD patients. PA was mainly negatively associated with ECW/TBW ratio. It is a useful index for predicting heart failure in diabetic HD patients.