Association between different measurements of obesity and the incidence of hypertension

Background: Obesity is a risk factor for the incidence of hypertension, but it is still unclear whether this risk can be better estimated by body mass index (BMI) or waist circumference (WC). Methods: In the baseline evaluation of a population-based cohort, 1089 adults answered a pretested questionnaire and had their baseline blood pressure (BP) and anthropometric measurements assessed according to standardized recommendations. Excluding the individuals with hypertension at baseline, and those deceased or lost during the follow-up, 592 individuals (80.5% of those eligible) were visited again. Obesity was defined as BMI greater than or equal to30 kg/m(2) for both genders, and WC greater than or equal to102 cm for men and WC greater than or equal to88 cm for women. Incident cases of hypertension were characterized by BP greater than or equal to140/90 turn Hg or use of BP medication in the follow-up visit. Results: After a mean follow-up of 5.6 +/- 1.1 years, 127 incident cases of hypertension were identified. The hazard ratios (Cox model), adjusted for age and baseline systolic BP (95% CI and P), for BMI higher than 30 kg/m(2) were 1.08 (0.52-2.24, P = .82) in men and 1.74 (0.93-3.26, P = .08) in women. The corresponding figures were 1.78 (0.76-4.09, P = .18) for men with WC greater than or equal to102, and 1.72 (1.09-2.73, P = .02) for women with WC greater than or equal to88 cm. Conclusions: We conclude that the risk for hypertension may be better identified by obesity defined by higher WC than higher BMI. (C) 2004 American Journal of Hypertension, Ltd.