MO790PREDICTORS OF ERYTHROPOIETIN HIPORESPONSIVENESS IN PREVALENT PATIENTS ON PERITONEAL DIALYSIS: A CROSS-SECTIONAL STUDY

Background and Aims Anemia resistant to recombinant human erythropoietin (EPO) is a risk factor for mortality in dialyzed patients with chronic kidney disease. Identifying the causes of hyporesponsiveness may help overcome this resistance. The aim of this study was to investigate the risk factors of EPO hyporesponsiveness in a prevalent population of patients on peritoneal dialysis (PD). Method Cross-sectional study involving 50 prevalent DP patients. To evaluate the dose–response effect of EPO therapy, we used the erythropoietin resistance index (ERI), calculated as the average weekly weight-adjusted dose of EPO (U/Kg per week) divided by the average hemoglobin level (g/dL), over a 3-month period. Patients were classified in two groups according to ERI: ERI ≤ 10 and ERI > 10. We compared clinical, analytical and demographic data among groups. Body composition and fluid volume were evaluated by bioimpedance using the body composition monitor (BCM). Logist regression analysis was performed to identify predictors of EPO hyporesponsiveness. Statistical analysis was executed using SPSS (Version 23 for Mac OSX). Results The average age of 50 prevalent DP patients was 52.04 ± 15.98 years, 29 (58%) were male, 29 (58%) were diabetic and 31 (64%) were treated with angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). Average hemoglobin level (Hb) was 10.99 ± 0.81g/dL and average ERI was 7.64 ± 7.25. Eleven patients (22%) had hyporesponsiveness to EPO therapy (ERI>10). There was no age, gender, cause of chronic kidney disease or PD modality difference among groups. There was also no difference in the use of ACEIs or ARBs. Hyporesponsive patients had lower body mass index (BMI) (22.94 ± 2.89 vs 26.74 ± 4.53Kg/m2, p=0.01) and lower lean tissue index (LTI) (9.96 ± 1.94 vs 16.23 ± 18.51Kg/m2, p=0.02), but not fat tissue index (FTI). Weekly creatinine clearance (peritoneal plus urinary), but not Kt/V, was also significantly lower in this group (68.76 ± 37.29 vs 87.84 ± 35.35L/1.73m2, p=0.028). Hyporesponsive patients had lower urine volume (0.73 ± 0.63 vs 1.39 ± 0.67L, p=0.005) and residual kidney function (3.43 ± 3.04 vs 6.13 ± 3.69mL/min/1.73m2, p=0.044). The proportion of patients with fluid overload, defined as overhydration (OH)/extracellular water (ECW) > 15%, was significantly higher in this group (p=0.04). No difference was observed in albumin, c-reactive protein, serum iron, serum ferritin, transferrin saturation index or parathormone among groups. In a logist regression analysis, BMI [(OR) 0.56 (CI: 0.364-0.849)] and LTI [(OR) 0.315 (CI: 0.130-0.767)] were predictors of hyporesponsiveness to EPO therapy. Conclusion Lower BMI and lower LTI were predictors of resistance to EPO therapy in our study. Body composition, fluid status and residual kidney function seem to be the main factors influencing the response to EPO therapy in prevalent patients on PD, emphasizing the importance of strategies oriented to preserve residual kidney function in these patients.