Safety and efficacy of simvastatin in hypercholesterolemic patients undergoing chronic renal dialysis

Abstract

Dyslipidemia is universal but hypercholesterolemia per se is present in around 50% of dialysis patients. Although dietary therapy is of benefit in some, the majority require drug therapy. We compared the efficacy and safety of simvastatin plus an optimized lipid-lowering dialysis diet with placebo plus diet in a randomized, double-blind trial stratified for dialysis modality. Patients treated with hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) for at least 9 months and with serum non-high-density lipoprotein (HDL) cholesterol greater than 135 mg/dL, low-density lipoprotein (LDL) greater than 116 mg/dL, and triglyceride less than 600 mg/dL after a 6-week dietary treatment phase and an 8-week diet plus placebo run-in phase, were enrolled in the 24-week double-blind treatment phase. Fifty-seven patients (16 men, 41 women, median age 63 years, range 22-75 yr) were randomized 2:1 to diet plus 5 mg/day simvastatin (n = 38: 22 HD, 16 CAPD) or diet plus placebo (n = 19: 12 HD, 7 CAPD) for 24 weeks. Dose was doubled bimonthly (maximum 20 mg/day) if non-HDL cholesterol was greater than 135 mg/dL. Forty-two patients (73.7%) completed the trial. Comparing baseline and 24 weeks, simvastatin (median 10 mg/day) was significantly more effective than placebo in reducing serum non-HDL cholesterol concentrations. For HD, the median percentage changes for total cholesterol (TC) (simvastatin versus placebo) were -21.4% and -12.1% (P = 0.011), respectively; for LDL cholesterol, -33.0% and -8.8% (P = 0.023); for non-HDL cholesterol, -25.2% and -14.0% (P = 0.008); and for TC:HDL, -17.65% and -1.67% (P = 0.008). For CAPD, changes for TC were -22.1% and -1.5% (P = 0.003), respectively; for LDL, -36.4% and 0.0% (P = 0.001); for non-HDL cholesterol, -24.9% and -3.6% (P = 0.002); and for TC:HDL ratio, -21.49% and +9.74% (P = 0.045). Changes with CAPD in apolipoprotein (Apo) A1 were -4.7% and +4.0% (P = 0.031); and for ApoB, -19.9% and +2.6%, respectively (P = 0.031). There were no significant changes in ApoA1 or ApoB with HD. Compared with placebo, triglyceride levels fell 10.2% with HD and 6.2% with CAPD. HDL cholesterol was unchanged with HD but rose 8.5% with CAPD. These trends, however, did not reach statistical significance (P > 0.05). There was no effect on Lp (a). The incidence of clinical and laboratory adverse experiences were not increased in the simvastatin-treated patients compared with placebo. Simvastatin appears to be a safe and effective treatment for the reduction of serum non-HDL cholesterol levels in both HD and, particularly, CAPD patients.