Abstract: 【Abstract】bjective Erythropoietin (EPO) hypo-responsiveness is not rare in maintenance hemodialysis (MHD) patients, leading to refractory anemia. Identifying its influencing factors is crucial for guiding clinical intervention. Methods Patients undergoing maintenance hemodialysis at the Hemodialysis Center of Beijing Friendship Hospital from September 2022 to September 2023 were enrolled. Based on the median erythropoietin resistance index (ERI), they were divided into an ideal response group (ERI-T1 group) and a suboptimal response group (ERI-T2 group). The impact of demographic and laboratory indicators on ERI was further analyzed. Results A total of 236 patients were included, with 117 in the ERI-T1 group and 119 in the ERI-T2 group. The proportion of females was higher in the ERI-T2 group compared to the ERI-T1 group (t=-0.396, P＜0.001). Body mass index (Z=-2.088, P=0.037), hemoglobin (Z=-4.067, P＜0.001), serum iron (Z=-3.087, P=0.002), transferrin saturation (Z=- 2.216, P=0.027), and albumin (Z=- 3.226, P=0.001) were lower in the ERI-T2 group than in the ERI-T1 group. Correlation analysis showed that serum iron (r=-0.231, P=0.012) and albumin (r=-0.186, P=0.043) were negatively correlated with ERI. Multivariate linear regression analysis revealed that serum iron (β=-0.269, P=0.003) and albumin (β=-0.218, P=0.017) were independently and negatively correlated with ERI. Logistic regression analysis indicated that albumin was an independent protective factor against EPO hypo- responsiveness in maintenance hemodialysis patients (OR=0.881, 95% CI: 0.809～ 0.959, P=0.004). Conclusions Low serum iron and low albumin are modifiable risk factors for EPO hypo-responsiveness in MHD patients. Albumin can serve as a clinical practical predictive marker for EPO hypo-responsiveness. Clinical attention to patients' nutritional status is necessary to optimize anemia management.

Key words: Maintenance hemodialysis, Erythropoietin hypo- responsiveness, Erythropoietin resistance index, Albumin, Serum iron