Association between modified simple protein-energy wasting (PEW) score and all-cause mortality in patients receiving maintenance hemodialysis

Background Protein-energy wasting (PEW) is a frequently observed complication that leads to increased mortality in hemodialysis patients. However, a multifaceted assessment of PEW by combined objective nutritional parameters has not yet been established. Methods In total, 144 Japanese patients receiving maintenance hemodialysis at a hemodialysis center were retrospectively followed for 7 years. The primary outcome was all-cause death. The main exposure was a modified simple PEW score (0, 1, 2, 3, or 4), calculated from four parameters: serum albumin and creatinine levels, normalized protein catabolic rate, and body mass index. These parameters are included in the subcategories of PEW as defined by the International Society of Renal Nutrition and Management. The cutoff values of the modified simple PEW score components were based on the receiver operating characteristics curves determined by univariate logistic regression analyses. Risk estimates for all-cause mortality were calculated by the Cox proportional hazards model adjusted for potential confounding factors. Results During the median 5.7-years follow-up period, 37 patients died of any cause. When patients were divided into three subgroups (G1-G3) based on the modified simple PEW score, a multivariable-adjusted analysis showed that the risks of all-cause death in groups G2 and G3 were significantly higher than in the lowest score group (G1), with hazard risk (95% confidence interval) 3.10 (1.16-8.26) (P = 0.024) and 5.68 (1.85-17.45) (P = 0.002), respectively. Conclusions The modified simple PEW score is a useful composite indicator of nutritional status that stratifies the risk of all-cause mortality in patients undergoing maintenance hemodialysis.