Malnutrition and inflammation as predictors of mortality in peritoneal dialysis patients

Nutritional status is associated with clinical outcomes in dialysis patients. Inflammation may cause malnutrition and increases the risk of poor outcomes. We have investigated the relationship between nutritional markers, an inflammatory marker, and survival in 177 peritoneal dialysis (PD) patients, enrolled from 1991 to 2005. In 53 patients, bioimpedance analysis (BIA) measurements were conducted from November 2000. In a subgroup of 42 patients, we measured high-sensitivity C-reactive protein (CRP) and various nutritional markers including prealbumin serially from May 2003. All the patients were followed to April 2006. Mean enrollment albumin and prealbumin levels were 3.61±0.51 g/dl and 35.8±11.3 mg/dl, respectively. Mean and median enrollment CRPs were 13.53±20.81 (s.d.) and 7.15 mg/l, respectively. Higher enrollment levels of nutritional markers such as albumin (P<0.0001), prealbumin (P<0.0001), and creatinine (P=0.08) were associated with better survival. Single enrollment level of prealbumin was a significant predictor of mortality (relative risk (RR)=0.977, P=0.032) in PD patients followed up to 15 years. The BIA parameter phase angle, a nutritional marker, was independently and inversely associated with mortality risk (RR=0.536, P=0.01). Enrollment CRP was a significant independent risk factor for mortality (RR=1.025, P=0.035). CRP was inversely correlated with nutritional markers in PD patients. Malnutrition and inflammation are highly prevalent and often coexist in PD patients and each may additionally contribute to the high mortality in these patients. Dietary and therapeutic interventions to improve nutritional and chronic inflammatory status in these patients need further exploration.