Cholesterol, Atherosclerosis, and Coronary Heart Disease

Coronary Heart Disease affects close to 60 million Americans, leads to nearly half of all deaths, and costs society billions of dollars each year. One factor that contributes to coronary heart disease (CHD) is cholesterol. Cholesterol is an essential component of cell membranes and a precursor for a range of hormones; however, it is also involved in atherosclerotic plaque formation within the arterial intima. Patients with elevated levels of cholesterol, in particular, low-density lipoprotein cholesterol (LDL-C), have an increased risk for both fatal and nonfatal heart attacks. Reducing cholesterol levels with diet, exercise, and drugs has been shown to slow (and even reverse) the progression of atherosclerosis and to reduce the risk of myocardial infarction (MI). After 5 years, a 10% reduction in LDL-C results in a decrease in CHD of up to 50%.

Cholesterol circulates in the bloodstream with triglycerides and phospholipids (mostly lecithin) in small aggregates containing proteins. There are four "lipoprotein" classes: chylomicrons, very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL).