title: Comparison of the effects of tibolone and estrogen therapy on hemostasis in surgical menopause: a randomized, double-blind, placebo-controlled study.
abstract: OBJECTIVE
  To examine the effects of unopposed estrogen (E) and tibolone therapy on coagulation and natural anticoagulant systems in surgical menopause.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled study.
  
  
  METHODS
  University hospital clinic in Turkey.
  
  
  METHODS
  Ninety healthy surgically postmenopausal women.
  
  
  METHODS
  Ninety surgically postmenopausal women were randomized into three groups: unopposed conjugated ET (0.625 mg/d, group 1), tibolone (2.5 mg/d, group 2), and identical tablets of placebo (group 3).
  
  
  METHODS
  Effects on parameters in the clotting cascade at baseline and after 24 weeks of treatment.
  
  
  RESULTS
  After 6 months, fibrinogen, lipoprotein (a), and factor VIIa were decreased, and activated partial thromboplastin time was increased significantly in the ET group compared with in the placebo group. However, tibolone significantly decreased only the serum levels of factor VIIa and factor IX and prolonged the activated partial thromboplastin time, compared with placebo group. In addition, conjugated ET caused a significantly greater decrease in serum fibrinogen level than did tibolone.
  
  
  CONCLUSIONS
  Neither E nor tibolone therapy led to activation of coagulation in the surgically menopausal women. Both preparations changed the overall hemostatic balance to a more fibrinolytic state.
authors.affiliation: Clinic for Womens' Health, Infertility, and IVF Center, Ankara, Turkey.
authors.forename: Aygul
authors.initials: A
authors.lastname: Demirol
authors.forename: Suleyman
authors.initials: S
authors.lastname: Guven
authors.forename: Emine Seda
authors.initials: ES
authors.lastname: Guvendag Guven
authors.forename: Serafettin
authors.initials: S
authors.lastname: Kirazli
authors.forename: Timur
authors.initials: T
authors.lastname: Gurgan
authors.forename: Ali
authors.initials: A
authors.lastname: Ayhan
mesh_terms: D000990:Antithrombin III / Q000032:analysis; D001779:Blood Coagulation Factors / Q000032:analysis; D004311:Double-Blind Method; D004966:Estrogens, Conjugated (USP) / Q000494:pharmacology*; D005260:Female; D006487:Hemostasis / Q000187:drug effects*; D006801:Humans; D007044:Hysterectomy; D017270:Lipoprotein(a) / Q000097:blood; D008593:Menopause; D008875:Middle Aged; D009652:Norpregnenes / Q000494:pharmacology*; D010314:Partial Thromboplastin Time; D011446:Prospective Studies; D012489:Salpingostomy; D020246:Venous Thrombosis / Q000209:etiology
chemical_list: D001779:Blood Coagulation Factors; D004966:Estrogens, Conjugated (USP); D017270:Lipoprotein(a); D009652:Norpregnenes; D000990:Antithrombin III; C027385:tibolone