Lipid-lowering effects of simvastatin and gemfibrozil in CAPD patients: a prospective cross-over study

We compared the lipid-lowering effects of simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, and gemfibrozil, a fibric acid derivative, in 22 continuous ambulatory peritoneal dialysis patients whose serum total cholesterol and/or triglyceride levels were > or = 220 mg/dL after a standard diet for six months. The study group was first treated with gemfibrozil (600 mg/b.i.d.) for three months (stage 1). After a wash-out period of two months, during which no treatment was given, all of the patients became hyperlipidemic again and, therefore, were given simvastatin (10 mg/day) for three months (stage 2), which was followed by another two-month wash-out period. A control group, which served to evaluate the natural progression of pharmacologically untreated dyslipidemia, was followed during the same period. Blood determinations of triglyceride, total cholesterol, and high-density lipoprotein (HDL) cholesterol were performed after each step. Low-density lipoprotein (LDL) cholesterol and HDL ratio were calculated from the measured values. Both gemfibrozil and simvastatin improved all parameters of the lipid profile, but the effect of simvastatin was better than that of gemfibrozil (-69 vs -39 mg/dL for triglyceride and -95 vs -64 mg/dL for cholesterol), while their actions on LDL and HDL cholesterol were of equal magnitude. Two months after discontinuation of simvastatin, significant decreases of total cholesterol (-46 mg/dL) and triglyceride (-60 mg/dL) were still present, while these values had returned to pretreatment levels after stopping gemfibrozil. The HDL ratio remained markedlyhigher (p < 0.05) during the wash-out period after simvastatin, while it decreased to pretreatment values after gemfibrozil was stopped. The lipid profile of the control group did not change during the follow-up. Both drugs were well tolerated, and no serious side effects occurred.