title: Waist circumference cut-off values to predict the incidence of hypertension: an estimation from a Brazilian population-based cohort.
abstract: OBJECTIVE
  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.
  
  
  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 >or= 140/90 mmHg 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 87 cm in men and 80 cm 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Cardiology, Hospital de Clínicas de Porto Alegre, UFRGS, Brazil. mgus@terra.com.br
authors.forename: M
authors.initials: M
authors.lastname: Gus
authors.forename: F Tremea
authors.initials: FT
authors.lastname: Cichelero
authors.forename: C Medaglia
authors.initials: CM
authors.lastname: Moreira
authors.forename: G Fortes
authors.initials: GF
authors.lastname: Escobar
authors.forename: L Beltrami
authors.initials: LB
authors.lastname: Moreira
authors.forename: M
authors.initials: M
authors.lastname: Wiehe
authors.forename: S Costa
authors.initials: SC
authors.lastname: Fuchs
authors.forename: F Danni
authors.initials: FD
authors.lastname: Fuchs
mesh_terms: D000328:Adult; D000428:Alcohol Drinking; D001794:Blood Pressure; D001938:Brazil / Q000453:epidemiology; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012016:Reference Values; D012737:Sex Factors; D055105:Waist Circumference