Impact of heavy proteinuria on clinical outcomes in patients on incident peritoneal dialysis

BACKGROUND: There are few reports on the nutritional status changes and residual renal function (RRF) according to proteinuria levels in patients on peritoneal dialysis (PD). METHODS: A total of 388 patients on PD were enrolled. The patients were divided into 3 groups with respect to initial proteinuria: the A (n = 119; <500 mg/day), B (n = 218; 500-3,500 mg/day), and C groups (n = 51; >3,500 mg/day). RESULTS: The patients with higher proteinuria levels had a higher incidence of male sex, diabetes mellitus, and icodextrin use than those with lower proteinuria levels. Although initial peritoneal albumin loss in C group was lower than that detected in the other groups, no significant difference was observed in peritoneal albumin loss among the 3 groups at the end of follow-up period. At the time of PD initiation, the Geriatric nutritional risk index (GNRI) was lower in the C group than in the other 2 groups. However, at the end of the follow-up period, there was no significant difference in GNRI between the 3 groups. The GNRI increased, and the proteinuria level or RRF decreased more in the C group than in the other 2 groups. There were no significant differences in lean mass index or fat mass index change from the time of PD initiation to the end of the follow-up period. However, fat mass index and nPNA showed greater increases in the C group. The multivariate analysis revealed that proteinuria was negatively correlated with GNRI at the time of PD initiation and at the end of the follow-up period. The initial RRF and proteinuria were negatively correlated with the RRF decline during the follow-up. CONCLUSION: The attenuation of the nephrotic proteinuria, along with the RRF decline, was associated with the improvement of the malnutrition.