Blood pressure control and hormone replacement therapy in postmenopausal women at risk for coronary heart disease.

BACKGROUND Coronary heart disease (CHD) in women is strongly associated with estrogen deprivation. For example, risk for CHD increases dramatically after menopause. However, the role of hormone replacement therapy (HRT) in CHD prevention currently is unresolved. To better understand CHD in women, the precise mechanisms by which estrogen affects circulatory function require clarification. Evidence suggests that exogenous estrogen may affect blood pressure (BP) control, but its interaction with other CHD risk factors has not been systematically characterized. The present study examines the role of mildly elevated resting BP, family history of CHD, and HRT on BP responses to stress in postmenopausal women. METHODS Postmenopausal women on long-term HRT were recruited along with a control group of postmenopausal women not on HRT. These women were divided into higher versus lower risk for CHD on the basis of resting BP and family history of CHD. BP control mechanisms were assessed before, during, and after a computer-controlled laboratory stressor. RESULTS Results indicate that women with elevated resting BP and positive family history of CHD have exaggerated BP reactivity to stress and that HRT inhibits this effect. CONCLUSIONS This study suggests that unmedicated postmenopausal women with mildly elevated resting BP and positive family history of CHD have altered BP control as indicated by exaggerated BP responses to stress. HRT eliminates the cumulative effect of resting BP and family history on BP reactivity, suggesting that the circulatory effects of estrogen replacement may operate, at least in part, through normalization of BP reactivity in higher-risk postmenopausal women.