FIBRINOLYTIC POTENTIAL IS SIGNIFICANTLY INCREASED BY ESTROGEN-TREATMENT IN POSTMENOPAUSAL WOMEN WITH MILD DYSLIPIDEMIA

Objective-To study the effects of oestrogen replacement treatment on f ibrinolytic potential in postmenopausal women. Design-Randomised, doub le blind, placebo controlled trial of oral 17 beta-oestradiol. Setting -Subjects were evaluated in the outpatient setting. Patients-Nineteen postmenopausal women with mild dyslipidaemia, aged 44 to 69 years (mea n (SD) 55.7 (6.7)). Main outcome measures-Fibrinolytic activity (fibri n plate assay) and tissue plasminogen activator (t-PA) antigen were me asured at baseline and after three, six, and nine weeks of each treatm ent. Results-After nine weeks of 2 mg oestradiol treatment, there was a significant increase in fibrinolytic potential compared with placebo , as indicated by an increase in fibrinolytic activity (mean (SEM), 80 (9) v 54 (5) mm(2) of lysis in the fibrin plate, 2 mg v placebo, p = 0.002) and a decrease in t-PA antigen (5.8 (0.9) v 8.4 (1.2) ng/ml, 2 mg v placebo, p < 0.001). There was a similar trend with the 1 mg dose but the changes were less noticeable. Conclusions-Hormone replacement treatment with 17 beta-oestradiol for nine weeks significantly increa sed fibrinolytic potential in postmenopausal women with mild dyslipida emia. This suggests that the cardioprotective effect of oestrogen may be mediated, in part, by an increase in fibrinolytic potential.