RESUMO
Oral contraceptive use has been increasing in Brazil since the late 1970s, and oral contraceptives have been associated with higher incidence of cardiovascular diseases, including hypertension, since their release in the United States and Europe. We examined the association between oral contraceptive use and blood pressure levels in 1457 workers from 10 sectors of the economy, between the ages of 15 and 49 years, in São Paulo, Brazil. Oral contraceptive use was associated with higher age, lower parity, higher income, white ethnic group, and administrative occupations. Using multiple linear regression and logistic regression techniques, we evaluated blood pressure and hypertension differences between users and nonusers. Oral contraceptive users had a mean systolic blood pressure 2.6 mm Hg higher than nonusers after adjustment for multiple potential confounders, including age, income, parity, ethnicity, body mass index, and occupation. There was a statistically significant positive trend between length of time on oral contraceptives and mean systolic blood pressure levels. After adjustment for demographic and social variables, there were no differences between whites and blacks. Oral contraceptive users have an adjusted odds ratio for hypertension of 2.66 (95% CI: 1.51-4.70). The finding of an increasingly positive association between oral contraceptive use and mean systolic blood pressure level suggests cause and effect. This observation has substantial importance because systolic blood pressure is considered the primary predictor of blood pressure-associated morbidity and mortality. This may pose a particular problem in Brazil, since most women on oral contraceptives are not under medical supervision.