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Updated: Jul 12, 2026
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Changes in hemostatic variables induced by estrogen replacement therapy: comparison of transdermal and oral
Tomas Fait1, Michal Vrablik, Zdenek Zizka
1Department of Obstetrics and Gynecology, General Faculty Hospital and 1st Faculty of Medicine, Charles University, Prague, Czech Republic. tfait@seznam.cz
Aim:
The purpose of this study was to determine the changes of biochemical risk factors for thromboembolisms using different administration routes of early estrogen replacement therapy.
Methods:
In a 12-week prospective, randomized crossover trial, estradiol was administered orally (2 mg daily) or transdermally (0.05 mg daily). Forty-five healthy early postmenopausal women were included into the study within 12 weeks after hysterectomy and oophorectomy. Forty-one women (age 49 +/- 6 years) completed the study, and their data were analyzed. The hemocoagulation parameters were determined prior to beginning of the study and at the end of each treatment period, separated by a 1-week washout period.
Results:
After oral therapy, the average tissue factor pathway inhibitor levels decreased statistically significantly (p < 0.0001) from 87.5 +/- 39.1 to 68 +/- 37.49 ng/ml. The plaminogen activator inhibitor-1 levels also decreased statistically significantly (p = 0.001) after the oral estrogen therapy from 11.39 +/- 12.02 to 5.0 +/- 5.27 IU/l. These changes were also significant when compared with the nonsignificant changes after the transdermal therapy. No significant changes occurred in the levels of D-dimers. After both treatment methods, the antithrombin III and fibrinogen levels decreased, but within their physiological ranges.
Conclusions:
Oral administration of estrogen statistically significantly reduced the tissue factor pathway inhibitor and plasminogen activator inhibitor-1 levels when compared with the transdermal route. These changes cannot be unambiguously considered risky, and the zero change of D-dimers suggests that there was no activation of the coagulation cascade. We consider the neutral effect of the transdermal therapy more beneficial.
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