[Prevalence of Diabetes Mellitus in Southern Brazil: a population-based study]

To compare the prevalence of Diabetes Mellitus among the adult population of an urban area, according to self-reported diabetes and fasting glucose test results.

We carried out a population-based cross-sectional study of 1,968 subjects aged 20-69 years, living in the urban area of the city of Pelotas, Southern Brazil, in the year 2000. Sample size was calculated at 1,800 subjects. We visited the households of 40 randomly selected census sectors. We administered a standardized questionnaire to all subjects, which included questions on the presence of "blood sugar" and on medical confirmation in case of positive responses. A subsample of 367 participants was selected to donate blood samples for laboratory tests, including fasting blood glucose. We adopted as cutoff points for the detection of diabetes levels of 126 mg/dl and 140 mg/dl. Results are shown as frequencies and their respective 95% confidence intervals.

Of the subjects interviewed, 110 (5.6%; 95% CI: 4.6-6.6) referred the presence of Diabetes Mellitus diagnosed by a physician. In the subsample of 367 subjects who underwent blood testing, the prevalence of self-referred, physician-confirmed diabetes mellitus was 7.1% (95% CI: 4.5-9.7).

The prevalence estimates found in the present study are compatible with those obtained in other national surveys. Population-based studies are rare Brazil, and may contribute to the planning of health care policies.