Background: We examined the association between clustering of risk factors and the risk for coronary heart disease, stroke, and all-cause mortality.
Methods: Data from the First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study (N = 12,932) were used to estimate the relative risk for coronary heart disease (N = 2,255), stroke (N = 929), and death from any cause (N = 4,506) by the number of cardiovascular disease risk factors present. Risk factors included current smoking, overweight, hypertension, high blood cholesterol, and diabetes.
Results: The proportions of respondents with 0, 1, 2, 3, or > or = 4 risk factors were 25.0, 32.8, 27.8, 12.3, and 2.1%, respectively. Relative risks for coronary heart disease associated with having 1, 2, 3, and > or = 4 risk factors were 1.6 (95% confidence interval [CI] 1.4, 1.9), 2.2 (95% CI 1.9, 2.6), 3.1 (95% CI 2.6, 3.6), and 5.0 (95% CI 3.9, 6.3), respectively. Relative risks for stroke associated with the same risk levels were 1.4 (95% CI 1.1, 1.8), 1.9 (95% CI 1.5, 2.4), 2.3 (95% CI 1.7, 3.0), and 4.3 (95% CI 3.0, 6.3), respectively. Similar results were observed for all-cause mortality.
Conclusions: Risk for cardiovascular disease and all-cause mortality increased substantially with each additional risk factor. This supports the continued need for primary prevention of cardiovascular disease risk factors.