Why treat dyslipidemia?

Considerable observational clinical trial data have been collected concerning abnormal lipid levels and coronary disease incidence over the past 20 years. Middle-aged men with elevated cholesterol levels have been studied the most. Affected individuals tend to experience greatly increased risk for atherosclerosis and myocardial infarction. Bile acid resins, nicotinic acid, fibrates, and statin therapies have all been associated with a decreased vascular disease incidence. In general, each percentage lowering in blood cholesterol level has been associated with a 2% lowering in coronary heart disease incidence over a 5-year follow-up interval. Complementary data from atherosclerosis regression trials have shown that-persons taking lipid lowering medication typically exhibit less progression of atherosclerotic lesions in coronary and carotid arteries. Less data is available concerning the efficacy of lipid lowering in women and the elderly, but observational data suggest some benefit might be expected. Most clinical trials have emphasized the importance of lipid intervention using medications, but dietary trials have also demonstrated efficacy, and current dietary recommendations call for middle-aged persons to consume less than 30% of their calories as fat. While the impact of dyslipidemia on coronary heart disease has been emphasized, it is also important to recognize that control of lipids may have long-term impact on other diseases, such as diabetes mellitus, carotid stenosis, and pancreatitis.