Prior oral contraceptive use is associated with higher blood pressure in older women

Studies of young, premenopausal women suggest that changes in coronary risk factors do not persist after discontinuation of oral contraceptive use. However, little is known about longterm effects of past oral contraceptive use in older, postmenopausal women, who typically have a more atherogenic profile. This study examines the relation of past oral contraceptive use (including duration) to heart disease risk factors in postmenopausal women. Subjects were 517 women aged 50-69 from the Rancho Bernardo Study who attended follow-up clinic visits. Past oral contraceptive use was reported by 24.2% and two thirds had used oral contraceptives less than or equal to 5 years. After adjustment for covariates, the only significant difference was that past users had higher diastolic blood pressures than never users (p < 0.01). Among older women, the diastolic blood pressure of past users was 3.9 mm Hg higher than that of never users (p < 0.01). Women who used oral contraceptives for less than or equal to 5 years had diastolic blood pressures 3.6 mm Hg higher than those of never users (p < 0.01). No differences were found among younger women or those who used oral contraceptives greater than or equal to 6 years. Past oral contraceptive users may be at increased risk for heart disease because of a small but significant elevation in diastolic blood pressure that persists many years after discontinuing oral contraceptive use.