Abstract: Objective This study was carried out to identify the factors that contribute to the erythropoietin hyporesponsiveness in patients on maintenance hemodialysis (MHD). Methods Demographic data, hemoglobin, dose of erythropoietin, biochemical and other related indicators were collected from 80 MHD patients and analyzed retrospectively. They were followed up for 12 months. Erythropoietin resistance index (ERI) calculated by means of dividing the weekly weight (kg) adjusted dose of ESA (IU) by the hemoglobin level (g/dL) was used to evaluate the response to erythropoietin in MHD patients. Logistic regression was used to determine the key variables that might be independently involved in the erythropoietin hyporesponsiveness in MHD patients. Results The mean ERI for the entire study population was 16 IU/kg/week/g/dl, and 20% of the patients had erythropoietin hyporesponsiveness. Patients were them divided into two groups
according to ERI: ERI ＜25 IU/week/kg/g/dl group and ERI ≥25 IU/week/kg/g/dl group. In ERI ≥25 group, the proportion of female was higher (χ2=3.972, P=0.046), and hemoglobin and 25(OH)D were significantly lower than those in ERI ＜25 group (t=3.123 vs. 2.606; P=0.003 vs. 0.011). In addition, body mass index (BMI) and serum cholesterol were lower in ERI ≥25 group than in ERI ＜25 group (t=1.969, P=0.053). Logistic regression demonstrated that adjusted gender, dialysis vintage, BMI, Kt/V, serum cholesterol, serum albumin, alkaline phosphatase, and 25(OH)D deficiency were the independent factors for erythropoietin hyporesponsiveness (HR: 4.590; 95% CI: 1.277～16.503). Conclusion The prevalence of erythropoietin hyporesponsiveness was higher among MHD patients in our hemodialysis center. Female gender and malnutrition correlated to erythropoietin hyporesponsiveness, and 25(OH)D deficiency was the main risk factor for erythropoietin hyporesponsiveness. Improving 25(OH)D deficiency and malnutrition will raise erythropoietin respon siveness in MHD patients.

Key words: hemadialysis, anemia, erythropoietin, erythropoietin resistence index(ERI)