Body mass index, hypertension and 5-year coronary heart disease incidence in middle aged men: the PRIME study.

OBJECTIVE: The aim of the present study was to assess the joint contribution of hypertension and body mass index to coronary heart disease risk. DESIGN Prospective study on men aged 50-59 years free of coronary heart disease at entry recruited in three regions of France (n = 7359) and in Northern Ireland (n = 2399). PARTICIPANTS: The recruitment frame was based on industry and various employment groups, on health screening centers and general practice. MAIN OUTCOME: Incident cases of effort angina, unstable angina, myocardial infarction and coronary death were recorded over a 5-year follow-up. RESULTS: Compared with the reference group [body mass index (BMI) 25 kg/m2], the relative risk of coronary event was higher in the second (25 < or =BMI 27.6) and third BMI tertiles: 1.27 (95% confidence interval 0.94-1.70) and 1.14 (0.84-1.56) after adjustment for confounders and covariates, including diabetes, hypertension and lipoprotein levels. Further analyses revealed a significant interaction between hypertension and BMI on coronary disease risk (P <0.05), suggesting that hypertension modifies coronary heart disease (CHD) risk attributable to BMI. Among hypertensive men, the relative risk of coronary heart disease was 1.34 (0.85-2.11) and 1.61 (1.04-2.50) in the second and third BMI tertiles, respectively. In normotensive men, BMI was not associated with CHD risk; relative risk 1.25 (0.85-1.85) and 0.66 (0.40-1.09) in the second and third BMI, respectively. CONCLUSION: These results indicate that hypertension and overweight jointly increase coronary heart disease risk.