Is the association of hypertension with cardiovascular events stronger among the lean and normal weight than among the overweight and obese? The multi-ethnic study of atherosclerosis.

Previous studies that suggest the association of hypertension with cardiovascular disease (CVD) events is stronger in the lean/normal weight than in the obese have either included smokers, diabetics, or cancer patients, or did not account for central obesity. This study examines the interaction of adiposity with hypertension on CVD events using body mass index (BMI)-based definitions of overweight and obesity, as well as waist circumference (WC) to assess adiposity. In the Multi-Ethnic Study of Atherosclerosis, we classified 3657 nonsmoking men and women, free of baseline clinical CVD, diabetes mellitus and cancer, into 7 BMI-WC combinations defined by ethnicity-specific BMI (normal, overweight, class 1 obese, and class 2/3 obese) and ethnicity- and sex-specific WC categories (optimal or nonoptimal). Adjusted absolute event rates per 1000 person-years and relative risks (95% confidence intervals) for CVD events for hypertension (blood pressure ≥140/90 or taking medication) versus no hypertension computed within adiposity categories were 9.3 versus 1.9 and 4.96 (2.56-9.60) for normal BMI/optimal WC, 13.2 versus 4.2 and 3.13 (0.99-9.86) for normal BMI/nonoptimal WC, 9.0 versus 4.5 and 2.00 (1.19-3.36) for overweight BMI/optimal WC, 8.4 versus 5.6 and 1.50 (0.88-2.54) for overweight BMI/nonoptimal WC,14.1 versus 2.1 and 6.75 (0.69-65.57) for class 1 obese/optimal WC, 10.1 versus 3.7 and 2.69 (1.41-5.16) for class 1 obese/nonoptimal WC, and 9.9 versus 6.9 and 1.45(0.60-3.52) for class 2/3 obese/WC pooled. This study found a large relative risk of CVD events associated with hypertension for normal BMI participants and more importantly similarly high absolute risks for both normal and obese BMI with hypertension.