BLOOD PRESSURE CHANGES AND ORAL CONTRACEPTIVE USE: A STUDY OF 2676 BLACK WOMEN IN THE SOUTHEASTERN UNITED STATES

(BP) Blood pressure and weight were measured in 2676 black women attending a large southeastern family planning clinic. Repeat measurements were made after a minimum of 6 and up to 24 months on 673 women who continuously used nonhormonal contraceptive methods (control group) 613 women who initiated (OC) oral contraceptive therapy and 1390 who continuously used OCs. The mean change in (SBP) systolic blood pressure adjusted for initial BP and change in % ideal body weight is +1.44 mmHg in the new users of OCs. This slight increase in SBP is statistically significant (p=0.04) relative to the +0.41 mmHg increase observed in the control group. However the adjusted (DBP) diastolic blood pressure change (+0.46 mmHg in new OC users and +1.54 mmHg in the control group) fails to support the hypothesis of a greater increase in DBP in new OC users. The adjust mean rise in mean arterial BP does not differ significantly between new Oc users and the controls. The proportion of women developing a DBP> or = 90 mmHg during the average follow-up interval of 1 year is 2.4%. In the control group 1.0% in the new OC users and 0.2% in the continued OC users. These results provide evidence that OC use has no significant effect on the level of mean arterial BP in black women followed for 6-24 months; they also fail to support the hypothesis of a causal relationship between OC use and elevated BP in black women. (Authors modified)