Concurrent use of simvastatin and estrogen-progestin therapy compared with each therapy alone for hypercholesterolemia in postmenopausal women

Objective: Substantial improvements in lipoprotein-lipid profiles have previously been shown with both simvastatin and combined estrogen-progestin therapy in postmenopausal hypercholesterolemic women. Since little is known about the impact of the concomitant use of these therapies, the effects of concurrent hormone therapy and simvastatin in hypercholesterolemic postmenopausal women have been evaluated. Methods: Twenty-three postmenopausal women with fasting serum total cholesterol levels greater than 250 mg/dl received, in a randomized cross-over design, simvastatin (10 mg daily) for 8 weeks or postmenopausal hormone therapy (up to 1.25 mg of conjugated equine estrogens plus 5 mg of medroxyprogesterone acetate daily) for 8 weeks, with an 8-week wash-out interval between the two treatment periods. In a third, non-randomized treatment period after a second wash-out interval, each woman received a combination of simvastatin and postmenopausal hormone therapy in the same dosage regimens as above. Fasting blood was sampled monthly from baseline to measure total cholesterol, high- and low- density lipoprotein (HDL and LDL) cholesterol, triglycerides and lipoprotein(a). Results: For total cholesterol, the mean decreases with hormone therapy, simvastatin and combination therapy were 12% (95% confidence interval 6-17%), 26% (20-31%) and 28% (24-31%), respectively, and for LDL cholesterol 21% (14-27%), 37% (30-44%) and 46% (41-51%), respectively. Simvastatin was more effective than hormone therapy (p <0.001), while the effect of the combined therapy was even greater (total cholesterol, p = 0.012; LDL cholesterol, p <0.001). The level of HDL cholesterol increased similarly with each treatment: 4% (-3-11%), 6% (2-10%) and 7% (2-13%), respectively. Triglyceride levels increased with hormone therapy and decreased with simvastatin (p <0.001), while there was little change with the combination (effect of combined therapy vs. simvastatin, p = 0.002; vs. hormone therapy, p <0.001). Both hormone therapy and combined therapy reduced lipoprotein(a) similarly (-23% and -14%, respectively, p = 0.078). Simvastatin had no effect on lipoprotein(a) levels. Conclusion: For postmenopausal women with hypercholesterolemia, use of a statin in combination with continuous combined oral estrogen and progestin therapy can result in a more cardioprotective lipoprotein-lipid profile than that achieved with either therapy used alone.