Pirog M, et al. – A randomized controlled study is done to evaluate the impacts of different doses of oral hormone therapy (HT) on thrombin generation and fibrinolysis. In contrast to the standard HT, ultra–low–dose HT may enhance fibrinolysis through decreased PAI–1 levels.

Methods

• For this research, they designed a randomized controlled study.
• Total a 150 postmenopausal women were assigned in this study.
• In this study, the effect of standard dose (1 mg 17β–estradiol/5 mg dydrogesterone), ultra–low–dose HT (0.5 mg 17β–estradiol/2.5 mg dydrogesterone) on fibrinolysis and coagulation was compared to controls.
• Factors measured included plasma clot lysis time (CLT), fibrinolysis activators and inhibitors, thrombin generation (prothrombin fragments 1 + 2 [F1 + 2], endogenous thrombin potential [ETP]), normalized activated protein C sensitivity ratio (nAPCsr), and factor (F)VIII activity and were ascertained before and after 24 weeks of HT.

Results

• In ultra–low–dose group post treatment CLT tended to be shorter when compared to standard HT (–7%) and control group (–4%) with decreased plasminogen activator inhibitor–1 (PAI–1) antigen (by –16% vs both groups).
• Higher mean changes from baseline between ultra–low–HT group and standard group in CLT (–7.4 vs 3.05) and PAI–1 antigen concentration (–5.1 vs 0.9) were found.
• Standard HT, compared with the ultra–low–dose HT, led to higher F1 + 2 (+9%) and FVIII activity (+37%).