Serum β2-Microglobulin Predicts Mortality in Peritoneal Dialysis Patients: A Prospective Cohort Study

Background/Aims: beta(2)-Microglobulin (beta(2)-M) is a surrogate marker of middle-molecule uremic toxins and is associated with mortality in chronic hemodialysis patients. However, the impact of serum beta(2)-M levels on mortality in peritoneal dialysis (PD) patients is uncertain. The purpose of this study was to examine the association of serum beta(2)-M levels with allcause mortality in PD patients. Methods: A total of 771 PD patients were selected from the Clinical Research Center registry for end-stage renal disease cohort in Korea. Patients were categorized into 3 groups by tertiles of serum beta(2)-M levels. The primary outcome was all-cause mortality. Results: The median value of serum beta(2)-M was 23.6 mg/l (interquartile range 14.8-33.4 mg/l), and the median follow-up period was 39 months. The Kaplan-Meier analysis showed that the allcause mortality rate was significantly different according to tertiles of serum beta(2)-M in PD patients (p = 0.03, log-rank). Multivariate Cox proportional analysis showed that the hazards ratio for all-cause mortality was 1.02 (95% CI 1.01-1.04, p = 0.006) per 1 mg/l increase in beta(2)-M after adjustment for multiple confounding factors that relate to malnutrition and inflammation marker. However, serum beta(2)-M was not associated with all-cause mortality after adjustment for residual renal clearance. Conclusions: These results are supportive of the potential role of the serum beta(2)-M level as a predictor of mortality in PD patients. (C) 2015 S. Karger AG, Basel