Cholesterol and cardiovascular disease. An overview of Lipid Research Clinics (LRC) epidemiologic studies as background for the LRC Coronary Primary Prevention Trial.

The Lipid Research Clinics (LRC) Program has implemented an integrated series of observational epidemiologic, community-based studies that provide a frame of reference for the results of the LRC Coronary Primary Prevention Trial (CPPT). The observational studies were performed in 16 populations sampled in the United States, Canada, the Soviet Union and Israel. Findings based on data from more than 80,000 study participants indicate that atherogenic profiles of plasma total, low-density lipoprotein and high-density lipoprotein cholesterol levels are highly prevalent in middle-aged adults. The lipoprotein cholesterol fraction components are related to a wide range of demographic, behavioral, anthropometric, medical status, drug utilization and hormonal factors, in addition to the well known major dietary and genetic determinants. The results of the LRC CPPT are directly applicable to high-risk, high total cholesterol, and high low-density lipoprotein cholesterol levels in middle-aged men. Considered jointly with the observational finding that the major burden of ischemic heart disease is associated with moderately elevated lipid levels, the LRC studies suggest that 2 concurrent approaches are necessary to achieve community control: approaches for high-risk person through individualized medical intervention and hygienic, population-oriented approaches toward achieving less atherogenic distributions of lipids and lipoproteins. With this combined approach, the current epidemic of ischemic heart disease can be controlled.