Purpose: Raloxifene is a selective estrogen receptor modulator and an attractive alternative to estrogen replacement as it obviates the need for a progestin and does not increase C-reactive protein levels. We compared the effects of simvastatin and raloxifene treatments on the lipid profile, the levels of adhesion molecules and the endothelium dependent and independent vasoreactivity.
Subjects & methods: We treated 12 postmenopausal women with hypercholesterolemia and coronary artery disease with raloxifene 60 mg/day and simvastatin 20 mg/day in a randomized, double-blind, crossover study. Each treatment period was 8 weeks long with a 4-week washout interval. Plasma lipids and cellular adhesion molecules were evaluated and peripheral blood flow studies with venous occlusion plethysmography were performed.
Results: Both simvastatin and raloxifene significantly reduced total [33% (27-40), 12% (0-24)] and LDL [44% (36-52), 16% (0-33)] cholesterol compared to baseline values (p < 0.05) but simvastatin was more effective than raloxifene (p < 0.005). None of the treatments had any significant effect on HDL cholesterol and triglyceride levels. Only raloxifene significantly reduced Lp(a) [18% (1-36)] and ICAM-1 [17% (8-25)] and VCAM-1 [24% (15-33)] plasma levels compared to baseline (p = 0.019, p < 0.0001 and p = 0.003, respectively). Hyperemic blood flow response on raloxifene was significantly higher compared to baseline [52% (0-105)], (p < 0.05), whereas no significant change was noted on simvastatin. Endothelium independent blood flow induced by nitroglycerine was not influenced by either active treatment.
Conclusions: Raloxifene administration is associated with lower ICAM-1, VCAM-1 and Lp(a) plasma levels and enhanced endothelium dependent dilation compared to simvastatin although simvastatin is more powerful in total and LDL cholesterol reduction.