The Association of Lipid-Modifying Medications With Mortality in Patients on Long-Term Peritoneal Dialysis

Background The effect of lipid-lowering therapy on clinical outcomes in peritoneal dialysis patients has not been carefully addressed. Study Design Secondary analysis of a retrospective cohort study. Setting & Participants Data from 1,053 incident peritoneal dialysis patients from the US Renal Data System prospective Dialysis Morbidity and Mortality Wave 2 study. Predictor Use of lipid-modifying medications (93% statins, 7% other medications). Outcomes & Measurements Cox regression with propensity score adjustment was used to evaluate time to cardiovascular or all-cause mortality during a 2-year follow-up period. Subgroups based on predefined cutoff values for serum total cholesterol or triglycerides, presence of diabetes, and comorbidity index were analyzed separately. Results Use of lipid-modifying medications was associated with decreased all-cause (hazard ratio [HR], 0.74; 95% confidence interval, 0.56 to 0.98) and cardiovascular (HR, 0.67; 95% confidence interval, 0.47 to 0.95) mortality compared with no use of lipid-modifying medications. In subgroup analyses, use of lipid-modifying medications was associated with decreased all-cause mortality (HR, 0.46; 95% confidence interval, 0.22 to 0.95) in the subgroups with cholesterol levels of 226 to 275 mg/dL (HR, 0.27; 95% confidence interval, 0.09 to 0.80) and cholesterol levels greater than 275 mg/dL and cardiovascular mortality (HR, 0.31; 95% confidence interval, 0.11 to 0.85) in the subgroup with cholesterol levels of 226 to 275 mg/dL. Use of lipid-modifying medications also was associated with decreased cardiovascular mortality (HR, 0.64; 95% confidence interval, 0.41 to 0.99) in patients with diabetes and decreased all-cause (HR, 0.65; 95% confidence interval, 0.45 to 0.94) and cardiovascular mortality (HR, 0.55; 95% confidence interval, 0.35 to 0.87) in those with Charlson Comorbidity Index score higher than 2. Limitations Observational study with retrospective design. Considerable amount of missing data and limited amount of information for the extreme values of cholesterol and triglycerides. Conclusions These observational data suggest that lipid-modifying medication therapy may be associated with improved clinical outcomes in peritoneal dialysis patients.