Overall and central obesity incidence in an urban Portuguese population.

OBJECTIVE To provide overall and central obesity incidence estimates by gender, age and educational level in an urban Portuguese population. METHODS As part of the EPIPorto study, 1,621 Porto, Portugal adult residents were evaluated in 1999-2003 and 2005-2008. Overall obesity was defined by a BMI > or = 30.0 kg/m(2) and central obesity by a WC >88.0 cm in women and >102.0 cm in men. Relative risks (RR) and 95% confidence intervals (95% CI) were computed using Poisson regression. Survival analysis was also performed. RESULTS The age-adjusted incidence rates/100 person-years of overall and central obesity were, respectively, 1.70, 95% CI: 1.34-2.19 and 5.97, 95% CI: 5.09-7.03 in women; 1.08, 95% CI: 0.73-1.64 and 2.38, 95% CI: 1.81-3.20 in men. In multivariate analysis, older women presented a higher risk of overall obesity. Moreover, a significant inverse association was found between obesity and education in women (>11 vs. <5 years: RR=0.43, 95% CI: 0.22-0.84, for overall obesity; RR=0.45 95% CI: 0.29-0.69, for central obesity). For overall obesity, 10.1% of women and 5.1% of men became obese during the 5-year study period. Higher proportions were observed regarding central obesity, 29.1% and 11.4% for women and men, respectively. CONCLUSIONS Over time, individuals developed central obesity faster than overall obesity. Our results support that increasing levels of education limit this ongoing development of obesity, particularly among women.