Warfarin use and risk for osteoporosis in elderly women. Study of Osteoporotic Fractures Research Group.
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.
Jamal
S A
SA
University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, USA. sophie_jamal@quickmail.ucsf.edu
Browner
W S
WS
Bauer
D C
DC
Cummings
S R
SR
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*
D000925:Anticoagulants; D014859:Warfarin