EFFECTS OF ESTROGEN REPLACEMENT THERAPY ON THROMBIN GENERATION

Abstract

The aim of this study was to investigate the hemostatic system in menopausal women before and after three months of treatment with transdermal estradiol (TTS 50, 50 μg/die, n=13) or conjugated equine estrogen (CEE, 0.625 mg/die, n=9) by evaluating : beta-thromboglobulin, platelet factor 4, factor VIIag, factor VIIc, fibrinopeptide A-FPA-, thrombin-antithrombin-TAT-complexes, antithrombin-AT-activity, protein C, plasma fibrinolytic activity (euglobulin clot lysis time), plasminogen and antiplasmin activity. FPA levels significantly increased during TTS 50 treatment (p<0.001) while protein C showed a slight but significant decrease in both treatments (TTS 50 p<0.001, CEE p< 0.05). TAT complexes and AT were found unaltered. Platelet function and fibrinolytic activity did not significantly change. A significant relationship between FPA and estradiol levels, which were significantly increased during TTS 50 therapy, was found (r = 0.40, p<0.05). These findings indicate that unopposed estradiol given by transdermal route induces a slight but significant blood clotting activation, which seems strictly related to its biological activity. Copyright © 1997 Elsevier Science Ltd