Renal anemia and hyporesponsiveness to ESA for preservation of residual kidney function in patients undergoing peritoneal dialysis.

Preservation of residual kidney function (RKF) is important in patients undergoing peritoneal dialysis (PD). We aimed to examine the association between anemia management and residual urine output using data from a nationwide survey of dialysis patients. After excluding patients with anuria at baseline from the Total cohort of 2,712, 659 of 1,640 patients developed anuria during a median follow-up of 2.5 (interquartile range: 1.5-4.2) years. Urine volume decreased more rapidly as hemoglobin decreased or as the erythropoiesis-stimulating agent (ESA) resistance index (ERI) increased. The hazard ratios with 95% confidence intervals for the development of anuria, defined as residual urine volume ≤ 100 mL/day, were 1.65 (1.20-2.27), 1.39 (1.08-1.77), and 1.32 (1.07-1.63) for hemoglobin levels of < 9.0, 9.0-9.9, and 10.0-10.9 g/dL compared with 11.0-11.9 g/dL, and 1.35 (1.10-1.66) and 1.41 (1.14-1.73) for the second and third tertiles of ERI compared with the first tertile. In conclusion, patients with a low hemoglobin level or a high ERI were more likely to experience a decline in residual urine output and to develop anuria. Further studies are needed to investigate the effects of interventions that could improve renal anemia and/or ESA hyporesponsiveness on RKF preservation.