In one study that added ezetimibe to statin therapy, for instance, LDL levels were reduced, HDL levels were increased, and triglyceride levels were lowered compared to statin plus placebo therapy.
Combination therapy also can have an additive effect on lowering LDL levels. The addition of the bile acid sequestrant colesevelam to statin therapy has been shown to result in an 8% to 12% greater reduction in LDL levels than statin therapy alone.
Niacin is also used with statin therapy, because the two drugs have complementary effects. A combination drug that contained both extended-release niacin and lovastatin (Advicor) was put to the test against atorvastatin and simvastatin in the Advicor Versus Other Cholesterol-modulating Agents Trial Evaluation (ADVOCATE). The combination drug lowered LDL levels, increased HDL levels, and decreased triglyceride levels better than atorvastatin or simvastatin alone.
Niacin plus statin combination therapy was also explored in the HDL-Atherosclerosis Treatment Study (HATS). Subjects who had already had coronary artery disease were given either placebo or niacin and simvastatin, with or without antioxidant vitamins. The group on niacin and simvastatin that did not receive antioxidants achieved a 42% reduction in LDL levels, a 36% decrease in triglycerides, a 26% increase in HDL levels, and a 90% reduction in coronary events. (The group taking antioxidants with niacin and simvastatin had slightly lesser improvements in cholesterol, but more important, the reduction in cardiovascular events disappeared.) LDL levels in the placebo groups were unchanged.
The goal of lipid therapy in diabetes is to return the levels of all lipids to as close to normal as possible. (See “Metabolic Sydrome and Lipid Goals.”) It is achievable in nearly every person, and the arsenal of drugs that can add to the benefits of diet and exercise is growing steadily.