Hemostatic factors according to menopausal status and use of hormone replacement therapy

Abstract

The rise in cardiovascular disease (CVD) risk after menopause may be reduced by hormone replacement therapy (HRT) although the mechanism is unclear. Because little is known about the potential role of hemostatic factors, fibrinogen level and other coagulation parameters were measured in a study on the change in CVD risk factors through the climacteric (the Healthy Women Study). Of 239 subjects measured to date, 32 taking aspirin or other medications thought to alter coagulation were excluded from analyses. Results (adjusted for age and obesity) showed that women taking HRT had lower plasma concentrations of fibrinogen and higher levels of plasminogen and factor VIIc than did postmenopausal subjects not taking HRT. Pre- as compared with postmenopausal women had lower plasma levels of fibrinogen, factor VIIc, and antithrombin III. Adjusting for cigarette smoking did not change the findings. Thus, among women aged 49 to 55, selected hemostatic measures varied (within normal ranges) by menopausal status and were altered by HRT. These findings generally support a hypothesis of hemostatic change contributing to the increase of CVD after menopause. The fact that subjects taking HRT showed no increase in fibrinogen relative to premenopausal women is consistent with an observed decreased risk of CVD among women taking HRT, while the implication of an elevation in factor VIII among these women is uncertain.