MO798: Impact of Body Composition on Erythropoietin Resistance Index in Patients Receiving Chronic Hemodialysis

Abstract

Abstract BACKGROUND AND AIMS Erythropoietin resistance index (ERI) seems to be a predictor for adverse outcomes in patients receiving chronic hemodialysis. Despite the role of erythropoietin in non-hematopoietic tissues such as skeletal muscle or fat, clinical studies investigating the association between body composition and ERI are still lacking. The aim of this study was to examine the longitudinal impact of body composition on ERI in patients on chronic hemodialysis. METHOD This study included outpatients on chronic hemodialysis who received body composition analysis, which was performed every 6 months. The ERI was calculated by dividing the weekly body weight-adjusted erythropoietin dose by the hemoglobin concentration, and the values were averaged every 3 months period. The relationship between body composition and baseline ERI was evaluated in the multiple linear regression analysis, and the trend of ERI over time according to the changes in body composition was analyzed using a linear mixed effect model. RESULTS There were 65 (52.8%) men and 58 (47.2%) women, and they were followed up for 24 (5, 75) months. Subjects with higher mean ERI during the study period had increased risks for all-cause death, cardiovascular events and infection requiring hospitalization, compared with those with lower mean ERI (P = .009, .076 and .051). Linear regression analyses found that the ERI was negatively correlated to body mass index, % body fat, arm circumference, arm muscle circumference, and visceral fat area (P = .067, .065, .002, .021 and .040). However, the ratio of extracellular water to total body water and skeletal muscle mass index was not related to ERI. The longitudinal trend of ERI was compared according to the slope of body composition parameters over time. The increase in ERI was associated with the increase in the ratio of extracellular water to total body water (P = .007). On the other hand, the trajectory of ERI was inversely related to the longitudinal changes in arm circumference, arm muscle circumference and visceral fat area (P = .002, P < .001 and P = .026). CONCLUSION The ERI seems to be associated with body composition; therefore, body composition analysis can be useful to predict erythropoietin resistance in patients receiving chronic hemodialysis. Further studies are needed to investigate whether lifestyle modifications, including nutrition and exercise, can result in positive effects on body composition and responsiveness to erythropoietin.