Waist circumference cut-off values to predict the incidence of hypertension: An estimation from a Brazilian population-based cohort☆
Received 5 September 2007; received in revised form 11 March 2008; accepted 17 March 2008. published online 01 August 2008.
Abstract
Background and aims
Central obesity is a key component in the definition of the metabolic syndrome, but the cut-off values proposed to define abnormal values vary among different guidelines and are mostly based on cross-sectional studies. In this study, we identify the best cut-off values for waist circumference (WC) associated with the incidence of hypertension.
Methods and results
Participants for this prospectively planned cohort study were 589 individuals who were free of hypertension and selected at random from the community of Porto Alegre, Brazil. Hypertension was defined by a blood pressure measurement≥140/90mmHg or the use of blood pressure lowering drugs. A logistic regression model established the association between WC and the incidence of hypertension. A receiver operating characteristics (ROC) curve analysis was used to select the best WC cut-off point to predict the incidence of hypertension. During a mean follow-up of 5.5±0.9 years, 127 subjects developed hypertension. The hazard ratios for the development of hypertension, adjusted for age, baseline systolic blood pressure, alcohol consumption, gender and scholarship were 1.02 (95% CI; 1.00–1.04; P=0.02) for WC. The best cut-off WC values to predict hypertension were 87cm in men and 80cm in women, with an area under the curve of 0.56 (95% CI; 0.47–0.64; P=0.17) and 0.70 (95% CI; 0.63–0.77; P<0.001), respectively.
Conclusion
Excess visceral adiposity is a major risk factor for hypertension in individuals living in communities in Brazil, and this risk begins at lower values of WC that those recommended by some guidelines.
aDivision of Cardiology, Hospital de Clínicas de Porto Alegre, UFRGS, Brazil
bDivision of Clinical Pharmacology, Hospital de Clínicas de Porto Alegre, UFRGS, Brazil
cDepartment of Social Medicine, Faculdade de Medicina, UFRGS, Brazil
Corresponding author. Serviço de Cardiologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcelos, 2350, 90.035-903, Porto Alegre, RS, Brazil. Tel./fax: +55 51 2101 8420.
☆ Supported by grants from: Conselho Nacional de Pesquisa (CNPq) and Fundação de Amparo a Pesquisa do Rio Grande do Sul.
ABSTRACT