title: Warfarin use and risk for osteoporosis in elderly women. Study of Osteoporotic Fractures Research Group.
abstract: BACKGROUND
  Vitamin K deficiency may be associated with osteoporosis.
  
  
  OBJECTIVE
  To assess the effects of warfarin on bone.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Four centers in the United States.
  
  
  METHODS
  6201 elderly, postmenopausal women.
  
  
  METHODS
  Self-reported warfarin use, bone mineral density at the hip and the heel, hip bone loss over 2 years, and fractures during 3.5 years of follow-up. Analyses were adjusted for baseline differences, age, weight, and estrogen use.
  
  
  RESULTS
  Compared with warfarin nonusers (n = 6052), warfarin users (n = 149) more frequently had poor health, involuntary weight loss, nonthiazide diuretic use, and frailty but had similar bone mineral density at the hip (difference, 1.6% [95% CI, -0.7% to 4.1%]) and heel (difference, 2.1% [CI, -1.6% to 5.6%]). Users and nonusers had similar rates of bone loss (1.1% and 0.8%; P = 0.18) and fractures (relative hazard, 1.0 [CI, 0.60 to 1.71).
  
  
  CONCLUSIONS
  In this population, warfarin use did not decrease bone mineral density or increase fracture rates.
authors.affiliation: University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, USA. sophie_jamal@quickmail.ucsf.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Jamal
authors.forename: W S
authors.initials: WS
authors.lastname: Browner
authors.forename: D C
authors.initials: DC
authors.lastname: Bauer
authors.forename: S R
authors.initials: SR
authors.lastname: Cummings
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000209:etiology*; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000150:complications*; D012307:Risk Factors; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin