Objective: To assess whether the blood pressure is higher among women who take oral contraceptives than it is among those who do not.
Design: A cross-sectional survey of a stratified random sample of English adults (aged > or = 16 years).
Setting: Non-institutionalized households in England during 1994.
Participants: From this sociodemographically representative sample of English adults, 3545 premenopausal women, of whom 892 were current users of oral contraceptives, were evaluated.
Interventions: 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.
Main outcome measures: Systolic and diastolic blood pressures adjusted for potential confounders by oral-contraceptive-user status.
Results: 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.
Conclusions: 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.
PIP: The association between blood pressure and oral contraceptive (OC) use was investigated in 3545 randomly selected premenopausal women included in the 1994 Health Survey for England. 892 (25.2%) of these women were current OC users, 815 users of combined OCs and 77 of progestogen-only OCs. Age-adjusted mean diastolic and systolic blood pressure measurements were significantly higher among OC users (125/70 mmHg) than among non-users (123/68 mmHg) (p 0.001). This association remained significant even after adjustment for body mass index, alcohol consumption, physical activity, and hypertension treatment. Progestin-only OCs did not increase blood pressure, however. Finally, blood pressure differences between OC users and non-users tended to increase with age. Although the magnitude of the difference observed in the present study was small, these findings suggest that blood pressure should be checked before OCs are prescribed and monitored regularly throughout OC use. Women with hypertension who require OCs should be provided with progestogen-only formulations.