Nutritional predictors of mortality in prevalent peritoneal dialysis patients

Abstract

Malnutrition remains one of the major predictors of mortality in peritoneal dialysis (PD) patients. The aim of the study was to evaluate the nutritional status of prevalent PD patients, and to determine the best predictors of outcome among anthropometric and laboratory indices of nutrition. The study included 106 prevalent PD patients from a single university-based unit. Anthropometric assessment at baseline included: body mass, body mass index (BMI), skinfold thickness, lean body mass (LBM), content of body fat (%F), mid-arm muscle circumference (MAMC). Laboratory analysis comprised of albumin and total cholesterol. Additionally, each patient underwent a subjective global assessment (SGA). The patients were followed for 36 months. Survival analyses were made with the Kaplan-Meier survival curve and the Cox proportional hazard model. Following SGA, malnutrition was diagnosed in 30 (28%) patients. Importantly, eight of the malnourished patients (27%) were nevertheless overweight or obese. Body weight and BMI showed complete lack of association with the outcome. In Kaplan-Meier analysis low: LBM, MAMC, albumin and cholesterol were significantly related to mortality. Cox analysis revealed that, following adjustment, LBM below median was independently associated with poor outcome (hazard ratio [HR] 3.15, 95% confidence interval [CI] 1.17-8.49, p=0.02). Moreover, the lowest quartile of total cholesterol showed independent association with mortality (HR 8.68, CI 2.14-35.21, p<0.01). Malnutrition is prevalent in patients undergoing PD, and overweight/obesity does not preclude its appearance. The most valuable nutritional indices in predicting outcome in this cohort were LBM and total cholesterol concentration.