title: Oral conjugated equine estrogen increases plasma von Willebrand factor in postmenopausal women.
abstract: OBJECTIVE
  We sought to test whether one month of daily oral conjugated equine estrogen (CEE) or transdermal estradiol alters hemostatic factors in postmenopausal subjects.
  
  
  BACKGROUND
  Estrogen replacement therapy and hormonal replacement therapy (HRT) effect an early increase in cardiovascular events in postmenopausal women. Circulating plasma von Willebrand factor (vWF) antigen is a marker of generalized endothelial dysfunction and atherothrombosis.
  
  
  METHODS
  Thirty-eight healthy postmenopausal women (average 59 +/- 7 years) were randomized to receive daily oral CEE, 0.625 mg (n = 21); transdermal estradiol, 0.1 mg/day (n = 7); or oral placebo (n = 10) for one month. Blood samples were collected at baseline and after two weeks and four weeks of therapy for measurement of circulating plasma hormones, lipid concentrations, and hemostatic factors.
  
  
  RESULTS
  Oral CEE decreased total cholesterol (p < 0.01) and low-density lipoprotein cholesterol (p < 0.01), although it increased both triglycerides (p < 0.05) and high-density lipoprotein cholesterol (p < 0.01). Transdermal estradiol had no significant effect on lipids. Plasminogen activator inhibitor-1 antigen declined in both oral CEE and transdermal estradiol users, but did not achieve statistical significance. Fibrin D-dimer antigen did not vary significantly in any group. However, oral CEE users had a significant increase in vWF from baseline to four weeks (p < 0.03) and a decrease in tissue-type plasminogen activator antigen from baseline to four weeks (p < 0.004), which was significantly different from the change observed in the transdermal estradiol group (p < 0.05).
  
  
  CONCLUSIONS
  These data suggest that the oral CEE-mediated increase in plasma vWF may have clinical relevance given the early atherothrombotic effects of HRT in postmenopausal women.
authors.affiliation: Cardiology Division and Center for Women's Health, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
authors.forename: LeRoy E
authors.initials: LE
authors.lastname: Rabbani
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Seminario
authors.forename: Robert R
authors.initials: RR
authors.lastname: Sciacca
authors.forename: Hong Jun
authors.initials: HJ
authors.lastname: Chen
authors.forename: Elsa-Grace V
authors.initials: EG
authors.lastname: Giardina
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000368:Aged; D015415:Biomarkers / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood / Q000187:drug effects; D008078:Cholesterol, LDL / Q000097:blood / Q000187:drug effects; D004311:Double-Blind Method; D004958:Estradiol / Q000008:administration & dosage; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009518:New York; D017698:Postmenopause / Q000097:blood* / Q000187:drug effects*; D016896:Treatment Outcome; D014280:Triglycerides / Q000097:blood; D016387:Women's Health; D014841:von Willebrand Factor / Q000032:analysis* / Q000187:drug effects
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004966:Estrogens, Conjugated (USP); D014280:Triglycerides; D014841:von Willebrand Factor; D004958:Estradiol