Blood pressure response to orthostatic and mental challenge in African-American women taking oral contraceptives.
BACKGROUND
Contraceptive use among women with an elevated risk of cardiovascular disease and stroke has generated little concern among primary care physicians. African Americans in the southeastern region of the United States are particularly vulnerable to hypertension but are often neglected in research studies of cardiovascular disease. The current study examines the effect of oral contraceptive use by African-American women on blood pressure response to orthostatic and mental challenges.


METHODS
One hundred African-American women between the ages of 19 and 29 years were recruited from the student populations of Meharry Medical College and Flask University in Tennessee for a study of oral contraceptive use and blood pressure. Of 95 subjects on whom complete data were collected, 31 were taking oral contraceptives (OCs). As a measure of orthostatic challenge, each subject's blood pressure was monitored by a Dinamap automated instrument while she moved from a supine to sitting to standing position. To test blood pressure reactivity to mental challenge, a subset of 34 subjects (10 OC users and 24 nonusers) were monitored while they attempted to perform a frustrating cognitive task on a computer.


RESULTS
There were no differences between users and nonusers of oral contraceptives with respect to the amount of change in blood pressure associated with either the orthostatic or mental challenge. Levels of systolic blood pressure and mean arterial pressure, however, were consistently higher in subjects using oral contraceptives (P < .05) under both testing conditions. Systolic blood pressure levels were 6.7 mm Hg to 9.7 mm Hg higher in OC users during each of the three conditions of orthostatic challenge and 4.4 mm Hg to 7.4 mm Hg higher during each of the four periods of mental challenge. Among OC users, mean arterial pressure levels were 2.9 mm Hg to 4.7 mm Hg higher during orthostatic challenge and 5.0 mm Hg to 8.3 mm Hg higher during mental challenge.


CONCLUSIONS
While absolute levels of systolic blood pressure never exceeded 126 mm Hg under either testing condition, the difference in blood pressure levels between the OC users and nonusers warrants concern about the long-term effects of oral contraceptive use among African-American women. Although all OC users in this study were taking low-dose formulations, OC use did not eliminate the risk of elevated blood pressure in this population. Our findings suggest that caution is warranted and that alternative birth control methods should be advised for African-American women who have additional risk factors for cardiovascular disease.
McDermott
D S
DS
Department of Family and Preventive Medicine, Meharry Medical College, Nashville, TN 37208, USA.
Ernst
F A
FA
Nevels
H
H
Robertson
R M
RM
D000328:Adult; D044383:Black People; D001794:Blood Pressure / Q000187:drug effects*; D003276:Contraceptives, Oral / Q000009:adverse effects* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000139:chemically induced* / Q000503:physiopathology; D012307:Risk Factors; D013315:Stress, Psychological / Q000503:physiopathology; D013714:Tennessee; D001741:Black or African American
D003276:Contraceptives, Oral