Abstract: 【Abstract】Objective To investigate the relationship between serum 25- hydroxyvitamin D (25(OH)D) level and erythropoietin (EPO) hyporesponsiveness in maintenance hemodialysis (MHD) patients. Methods A total of 80 MHD patients were recruited and divided into three groups according to serum 25(OH)D level, severe deficiency group (＜5ng/ml, n=14), mild deficiency group (5～15ng/ml, n=38) and normal group (＞15ng/ml, n=28). Gender, age, body mass index (BMI), EPO dose, serum 25(OH)D, hemoglobin (Hb), highsensitivity C reactive protein (hsCRP), urea clearance rate (kt/V), creatinine clearance rate (Ccr) and other biochemical indexes were collected and analyzed. EPO resistance index (ERI) was used for the evaluation of EPO responseness. The difference of ERI and its correlation with serum 25(OH)D level were analyzed among the groups. Results The mean ERI was 13.514IU/(w?kg?g?dl) in all the MHD patients. EPO resistance was found in 15% of the patients. ERI was significantly different among the 3 groups (F=21.212, P＜0.001). Pearson correlation analysis showed that ERI was correlated with 25(OH)D (r=- 0.633, P=0.013), albumin (r=-0.330, P=0.003) and hsCRP (r=0.238, P=0.032). Multivariate logistic regression demonstrated that adjusted age, gender, dialysis vantage, Kt/V, intact parathyroid (iPTH), BMI, hsCRP, serum albumin and 25(0H)D deficiency were the independent factors for EPO hyporesponsiveness (HR: 3.355, 95% CI: 0.136～43.731, P=0.016). Conclusion Serum 25(OH)D deficiency is an independent risk factor for EPO hyporesponsiveness in MHD patients.

Key words: Maintenance hemodialysis, 25-hydroxyvitamin D, Erythropoietin, Renal anemia, Erythropoietin resistance index