Jeremiah Metzger Lecture: cholesterol, inflammation and atherosclerotic cardiovascular disease: is it all LDL?
Scientific investigation of the relationship between atherosclerosis, inflammation, and lipoprotein metabolism originated in the mid-19(th) century and has increased exponentially over the past 50 years. Basic research that characterized the lipoproteins and their metabolism was followed by clinical and epidemiologic studies that began to link elevated levels of cholesterol in the blood to the development of atherosclerosis and increased risk for cardiovascular disease. The link between elevated serum cholesterol levels and cardiovascular disease, known as the "lipid hypothesis," was confirmed with the discoveries of the low-density lipoprotein (LDL) receptor and of the statins. Subsequent results of multiple clinical trials, particularly with statins, have established that reductions in LDL cholesterol are associated with reduced risk for coronary heart disease (CHD). A growing body of evidence suggests that measures of inflammation, such as C-reactive protein (CRP), may enhance cardiovascular risk assessment and help guide clinical decision-making. Reductions in CRP in individuals with low serum levels of LDL cholesterol have been shown to reduce cardiovascular events. A variety of agents designed to further reduce LDL cholesterol, increase high-density lipoprotein (HDL) cholesterol, and target inflammation are currently in development. Future research can help clarify the roles of emerging biomarkers and lipid fractions other than LDL cholesterol in the prevention, diagnosis, and treatment of cardiovascular disease.