Effects of hormone replacement on hemostasis in spontaneous menopause.
OBJECTIVE
To examine the effects of continuous combined estrogen-progesterone replacement therapy on coagulation and natural anticoagulant systems in spontaneous menopause.


METHODS
A randomized, double-blind, placebo-controlled study was conducted during a 6-month period to examine the effect of hormone replacement therapy (HRT) on blood coagulation parameters. One hundred-ten healthy postmenopausal women were randomized into two groups. Those in group 1 were given conjugated estrogen (0.625 mg/d, Premarin) and medroxyprogesterone acetate (5 mg/d, Farlutal), and those in group 2 were given identical tablets of placebo for 6 months. Serum levels of modified activated protein C resistance, antithrombin III, fibrinogen, factor VIIIa, factor VIII, factor IX, activated partial thromboplastin time, prothrombin time, thrombin time, and lipoprotein (a) were measured before and 6 months after the treatment and analyzed for changes in extrinsic and intrinsic coagulation parameters.


RESULTS
At the end of the 6-month period, fibrinogen, lipoprotein (a), and activated protein C resistance levels were decreased significantly in the HRT group compared with the control group. Antithrombin III levels were increased, indicating antithrombin activity. Activated partial thromboplastin time, as a measure for intrinsic coagulation cascade, was prolonged in concert with decreased intrinsic coagulation factors, factor VIII, and factor IX (p < 0.05). In the extrinsic coagulation system, prothrombin time was significantly increased, although factor VIIa level was not changed (p > 0.05).


CONCLUSIONS
Significant changes were observed in the coagulation parameters, which may further explain the cardioprotective effect of HRT.
Department of Obstetrics and Gynecology, Hacettepe University Faculty of Medicine, Sihhiye, Ankara, Turkey.
A
A
Demirol
C
C
Baykal
S
S
Kirazli
A
A
Ayhan
D020016:Activated Protein C Resistance; D000328:Adult; D000990:Antithrombin III / Q000032:analysis; D001779:Blood Coagulation Factors / Q000032:analysis; D004311:Double-Blind Method; D015914:Estrogen Replacement Therapy; D005164:Factor IX / Q000032:analysis; D005169:Factor VIII / Q000032:analysis; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006487:Hemostasis / Q000187:drug effects*; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000627:therapeutic use; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D010919:Placebos; D011517:Prothrombin Time
D001779:Blood Coagulation Factors; D017270:Lipoprotein(a); D010919:Placebos; D000990:Antithrombin III; D005169:Factor VIII; D005164:Factor IX; D005340:Fibrinogen; D017258:Medroxyprogesterone Acetate