Overweight and Obesity as Determinants of Cardiovascular Risk: The Framingham Experience

BACKGROUND: To our knowledge, no single investigation concerning the long-term effects of overweight status on the risk for hypertension, hypercholesterolemia, diabetes mellitus, and cardiovascular sequelae has been reported. METHODS: Relations between categories of body mass index (BMI), cardiovascular disease risk factors, and vascular disease end points were examined prospectively in Framingham Heart Study participants aged 35 to 75 years, who were followed up to 44 years. The primary outcome was new cardiovascular disease, which included angina pectoris, myocardial infarction, coronary heart disease, or stroke. Analyses compared overweight (BMI [calculated as weight in kilograms divided by the square of height in meters], 25.0-29.9) and obese persons (BMI > or =30) to a referent group of normal-weight persons (BMI, 18.5-24.9). RESULTS: The age-adjusted relative risk (RR) for new hypertension was highly associated with overweight status (men: RR, 1.46; women: RR, 1.75). New hypercholesterolemia and diabetes mellitus were less highly associated with excess adiposity. The age-adjusted RR (confidence interval [CI]) for cardiovascular disease was increased among those who were overweight (men: 1.21 [1.05-1.40]; women: 1.20 [1.03-1.41]) and the obese (men: 1.46 [1.20-1.77]; women: 1.64 [1.37-1.98]). High population attributable risks were related to excess weight (BMI > or =25) for the outcomes hypertension (26% men; 28% women), angina pectoris (26% men; 22% women), and coronary heart disease (23% men; 15% women). CONCLUSIONS: The overweight category is associated with increased relative and population attributable risk for hypertension and cardiovascular sequelae. Interventions to reduce adiposity and avoid excess weight may have large effects on the development of risk factors and cardiovascular disease at an individual and population level.