Changes in coagulation factors and fibrinolytic components of postmenopausal women receiving continuous hormone replacement therapy

Abstract

Objective The effect of hormone replacement therapy (HRT) on coagulation factors and fibrinolytic components in postmenopausal women was studied for 6 months to elucidate whether continuous HRT has an influence on thrombosis.Methods One hundred and thirty-four postmenopausal women were divided into three groups according to treatment: 39 women who had undergone hysterectomy and oophorectomy received 0.625 mg/day of conjugated equine estrogen (CEE) continuously (CEE therapy), 48 postmenopausal women received both 0.625 mg/day of CEE and 2.5 mg/day of medroxyprogesterone acetate (MPA) continuously (CEE/MPA therapy) and 47 postmenopausal women received placebo as control. The following variables were measured before treatment as well as after 1, 3 and 6 months of treatment: factor VII activity, protein C activity, fibrinogen level, antithrombin III activity, plasminogen activator inhibitor-1 (PAI-1) level and the plasma concentration of tissue-type plasminogen activator (t-PA).Results After 1 month of treatment, protein C activity increased by 9.6% and 11.4% of the initial value (p < 0.05), fibrinogen level decreased by 7.8% and 6.1% of the initial value (p < 0.05) and PAI-1 decreased by 19.4% and 14.3% of the initial value (p < 0.05) in the CEE therapy group and the CEE/MPA therapy group, respectively. Factor VII activity increased by 10.1% of the initial value (p < 0.05) in the CEE therapy group only. Antithrombin III and t-PA levels did not change throughout either treatment.Conclusion Except for an increase in factor VII activity in the case of continuous CEE therapy, continuous HRT had no unfavorable effects on either coagulation factors or fibrinolytic components.