title: Haemostatic risk factors in healthy postmenopausal women taking hormone replacement therapy.
abstract: OBJECTIVE
  To compare changes in haemostatic parameters in healthy postmenopausal women taking either tibolone or 17beta-oestradiol/norethisterone acetate.
  
  
  METHODS
  Factor VIIc, antithrombin, fibrinogen, thrombin-antithrombin complex (TAT), FDP (D-Dimer), tissue plasminogen activator (tPA) and plasminogen activator inhibitor I (PAI-1) were measured in 80 healthy postmenopausal women after 3, 6 and 12 months therapy with either 17beta-oestradiol/norethisterone acetate or tibolone.
  
  
  RESULTS
  Both treatments significantly reduced fibrinogen, factor VIIc, antithrombin, tPA and PAI-1 antigen. Significantly lower levels of factor VIIc activity were observed on treatment with tibolone compared with 17beta-oestradiol/norethisterone acetate. TAT was unchanged with both treatments as was tPA activity. FDP (D-dimer) was increased on treatment with both preparations.
  
  
  CONCLUSIONS
  The enhanced fibrin turnover and reduced antithrombin activity may play a role in the increased risk of venous thromboembolism in some susceptible women taking hormone replacement therapy (HRT) and could explain the lack of benefit of HRT in the secondary prevention of cardiovascular disease. The decreased levels of fibrinogen and factor VIIc found during treatment with 17beta-oestradiol/norethisterone acetate or tibolone may offer some degree of cardioprotection in healthy woman without pre-existing disease.
authors.affiliation: Department of Obstetrics and Gynaecology, Trinity Centre for Health Sciences, St James's Hospital, 8, Dublin, Ireland. lnorris@tcd.ie
authors.forename: L A
authors.initials: LA
authors.lastname: Norris
authors.forename: M
authors.initials: M
authors.lastname: Joyce
authors.forename: N
authors.initials: N
authors.lastname: O'Keeffe
authors.forename: B L
authors.initials: BL
authors.lastname: Sheppard
authors.forename: J
authors.initials: J
authors.lastname: Bonnar
mesh_terms: D004958:Estradiol / Q000627:therapeutic use; D005260:Female; D006487:Hemostasis; D020249:Hormone Replacement Therapy; D006801:Humans; D008875:Middle Aged; D009640:Norethindrone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000077563:Norethindrone Acetate; D009652:Norpregnenes / Q000627:therapeutic use; D017698:Postmenopause; D012307:Risk Factors; D013997:Time Factors
chemical_list: D009652:Norpregnenes; D004958:Estradiol; D000077563:Norethindrone Acetate; C027385:tibolone; D009640:Norethindrone