Blood pressure in women using oral contraceptives: results from the Health Survey for England 1994.

Abstract

To assess whether the blood pressure is higher among women who take oral contraceptives than it is among those who do not. A cross-sectional survey of a stratified random sample of English adults (aged > or = 16 years). Non-institutionalized households in England during 1994. From this sociodemographically representative sample of English adults, 3545 premenopausal women, of whom 892 were current users of oral contraceptives, were evaluated. An interviewer-administered questionnaire determined details of menopausal status, use of oral contraceptives and antihypertensive agents and other sociodemographic variables. Measurements of the weight, height and blood pressure (the mean of the last two of three readings taken with a Dinamap 8100 device) were recorded. Systolic and diastolic blood pressures adjusted for potential confounders by oral-contraceptive-user status. Mean blood pressures adjusted for age were significantly higher among oral contraceptive users (125/70 mmHg) than they were among non-users (123/68 mmHg, P < 0.001 both for systolic and for diastolic blood pressures). These results remained unchanged after further adjustment for the body mass index, alcohol intake, physical activity and hypertension treatment. Blood pressure differences tended to be larger among older oral contraceptive users. Oral contraceptives containing progestogen only were not associated with higher blood pressures. Despite the fact that most combined oral contraceptives in current use in England contain low doses of oestrogen, slightly but significantly higher blood pressures were observed among oral contraceptive users. Blood pressures should be screened before oral contraceptives are supplied and should be monitored regularly during oral contraceptive use.