Overview of clinical trials of cholesterol lowering in relationship to epidemiologic studies

The results of clinical trials have produced convincing evidence of the direct relationship between total plasma cholesterol lowering and reduction in coronary heart disease risk. Quantitative overviews suggest efficacy in primary and secondary prevention of coronary heart disease, both in pharmacologic and dietary trials. Within-treatment group analyses (as observational epidemiologic studies) of the clinical trials and overview analyses of the aggregate outcome of the trials (as proper randomized experiments) are consistent with the results of population-based epidemiologic surveys: they disclose a continuous decrease in coronary heart disease risk with decreasing levels of total plasma cholesterol over a wide range of values. Integrated with knowledge of the distribution of plasma cholesterol levels in populations, these results indicate that there is a major potential for control of the contemporary epidemic of coronary heart disease by a combined high-risk individual and general population intervention approach to the reduction of plasma cholesterol levels.