Association between prognostic nutritional index and peritoneal dialysis discontinuation: a retrospective cohort study

Abstract Background Malnutrition is associated with discontinuing peritoneal dialysis (PD). The prognostic nutritional index (PNI), composed of serum albumin level and total lymphocyte count, has been suggested as a prognostic marker for mortality in patients undergoing PD. However, the relationship between PNI and PD discontinuation has not yet been well addressed. We evaluated the relationship between PNI and PD discontinuation in patients with end-stage kidney disease who initiated PD treatment. Methods This retrospective cohort study included patients who underwent PD at a single academic hospital between 2007 and 2022. We examined the association between PNI (< 40 vs. ≥ 40) and PD discontinuation using Cox proportional hazards regression models. We used restricted cubic spline analysis to examine the continuous associations between the PNI and outcomes. Results The mean age (and standard deviation) of the 91 patients was 57.1 ± 13.4 years; 72 (79.1%) discontinued PD during the median follow-up period of 25.0 months. Lower PNI was associated with an increased risk of PD discontinuation. The hazard ratios (95% confidence intervals) with three levels of adjustments were 1.74 (1.08, 2.79), 2.21 (1.32, 3.66), and 1.81 (1.01, 3.24) (reference: PNI ≥ 40). Restricted cubic spline analysis showed that a PNI < 40 was continuously associated with a higher risk of PD discontinuation. Conclusion A lower PNI (< 40) was associated with a higher risk of PD discontinuation. Our findings suggest that evaluating the PNI may help identify patients at high risk of PD discontinuation and lead to appropriate nutritional management for dialysis maintenance.