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.
Demirol
A
A
Department of Obstetrics and Gynecology, Hacettepe University Faculty of Medicine, Sihhiye, Ankara, Turkey.
Baykal
C
C
Kirazli
S
S
Ayhan
A
A
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