Onodera's prognostic nutritional index as a risk factor for mortality in peritoneal dialysis patients

The aim of this study was to evaluate the clinical relevance and usefulness of the Onodera's prognostic nutritional index (OPNI) as a prognostic and nutritional indicator in peritoneal dialysis (PD) patients. Patients were divided into 3 groups based on the initial OPNI score: group A (n = 186, < 40), group B (n = 150, 40-45), and group C (n = 186, > 45). Group A was associated with a higher grade according to the Davies risk index than the other groups. Serum creatinine and albumin levels, total lymphocyte count, and fat mass increased with an increase in OPNI. According to the edema index, the correlation coefficient for OPNI was -0.284 and for serum albumin was -0.322. Similarly, according to the C-reactive protein (CRP), the correlation coefficient for OPNI was -0.117 and for serum albumin was -0.169. Multivariate analysis adjusted for age, Davies risk index, CRP, and edema index revealed that the hazard ratios for low OPNI, serum albumin, and CRP were 1.672 (P = 0.003), 1.308 (P = 0.130), and 1.349 (P = 0.083), respectively. Our results demonstrate that the OPNI is a simple method that can be used for predicting the nutritional status and clinical outcome in PD patients.