The Normalized Protein Catabolic Rate and Mortality Risk of Patients on Hemodialysis by Frailty Status: The Japanese Dialysis Outcomes and Practice Pattern Study

Abstract

The appropriate protein intake for patients on hemodialysis complicated with frailty remains highly controversial. We conducted a prospective cohort study using data from Japanese Dialysis Outcomes and Practice Pattern Study. The patients were separated by their baseline of normalized protein catabolic rate (nPCR) into 3 categories: low (nPCR<1.0), medium (1.0≤nPCR <1.2), and high (nPCR ≥1.2). The frailty score was calculated based on the 12-item Short Form, and frailty was defined in cases with a total score of ≥2 points. The all-cause mortality was compared between groups using a Cox proportional hazard model. A total of 2,404 patients were included in the longitudinal analysis, 1,096 (45.6%) of whom had frailty. Patients in the low-nPCR group showed a higher prevalence of frailty than those in the other groups. In the Cox proportional hazard model, no significant differences in the all-cause mortality were noted between the low-nPCR and medium-nPCR groups or the high-nPCR and medium-nPCR groups. Furthermore, no significant differences were noted among any groups when subjects were limited to patients with frailty. Patients with a low nPCR have a higher prevalence of frailty and incidence of mortality than those with a medium nPCR. Patients with a high nPCR did not show a lower survival rate than those with a medium nPCR in this study. To clarify the appropriate protein intake for patients on hemodialysis with frailty, an intervention study or large-scale, long-term cohort study will be needed.