2006 Distinguished Scientist Lecture—Insights Provided by Framingham Population Research
The Framingham Study established the utility of population-based research for seeking out correctable predisposing conditions for cardiovascular disease (CVD), putting prevention at the forefront of cardiology. It established the risk factor concept of CVD evolution, recognizing that there is no single cause that is essential or sufficient by itself for CVD occurrence. It demonstrated the importance of distinguishing between usual (average) and optimal risk factor levels. It corrected clinical misconceptions about vascular disease, including: the hazard of atrial fibrillation; the relevance of diabetes as a macrovascular threat; the significance of left ventricular hypertrophy and small amounts of proteinuria; and the role of obesity, weight gain, and physical activity. Framingham investigation dispelled the concept of “benign essential hypertension” and the greater importance of diastolic blood pressure. It determined the full clinical spectrum of CVD, including sudden death, and silent coronary, stroke, and peripheral artery disease. The study determined CVD population incidence at a time when only mortality statistics were available, and now the lifetime risk. It quantified the hazard of a family history of CVD based on observations on parents and their offspring. The study provided insights on mechanisms of atherogenesis, including: LDL and HDL dyslipidemia, obesity-induced clustering of CVD risk factors, and smoking as a trigger for coronary attacks. It warned in 1985 of the lack of efficacy and danger of estrogen replacement for preventing CVD. The Framingham Study devised CVD risk profiles enabling physicians to pull together risk factor information to assess the global risk of heart attacks, failure, strokes, and peripheral artery disease. Findings of the study stimulated pharmaceutical industry development of agents for reducing blood pressure, lipids, glucose, and smoking, as well as trials demonstrating the efficacy of correcting risk factors. It also stimulated national campaigns against smoking, hypertension, hypercholesterolemia, and obesity.