Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


Anticonvulsant Use, Falls, Fractures and BMD: Findings From the Womens Health Initiative

Carbone1,  Laura, Johnson2,  Karen, Robbins3,  John, Larson4,  Joseph, Curb5,  J. David, Watson6,  Kathleen, Gass7,  Margery

Univ of Tenn at Memphis, Memphis, TN
University of TN, Memphis, TN
University of California, Davis, CA
Fred Hutchinson Cancer Research Center, Seattle, WA
University of Hawaii, HI
University of Washington, Seattle, WA
University of Cincinnatti
Fred Hutchinson, Seattle, WA

Purpose:

Anticonvulsants, particularly those that inhibit the cytochrome P450 enzyme- inducing system, may be associated with risks for fracture. The purpose of this study was to determine the relationship of anticonvulsant use to falls, fractures and bone mineral density (BMD) in postmenopausal women.

Methods:

We included 138,667 women (1,385 users of anticonvulsants and 137,282 non users of anticonvulsants) aged 50–79 who enrolled in the Women's Health Initiative (WHI) from 1993–1998. Women who had BMD measurements at baseline and year 3 (84 anticonvulsant users and 8,677 non users of anticonvulsants) were also examined. Incident falls and fractures were determined over an average of 7.7 years of follow-up. BMD changes from baseline to year 3 at the total hip, lumbar spine and total body were calculated.

Results:

After adjustment for covariates including age, ethnicity, BMI, calcium and vitamin D intake, prevalent fractures and falls, medication use, smoking and alcohol use, parental history of hip fractures, age of menopause, physical activity levels, physical function, self reported health, other medical conditions and WHI trial participation, use of anticonvulsants was positively associated with total fractures (HR 1.44 (95% CI 1.30,1.61), site specific fractures including hip fractures (HR 1.51 (95% CI 1.05, 2.17), clinical vertebral (HR 1.60 (95% CI 1.20, 2.12), lower arm or wrist (HR 1.40 (95% CI 1.11, 1.76) and other clinical fractures (HR 1.46 (95% CI 1.29, 1.65) and 2 or more falls ((HR 1.62 (95% CI 1.50, 1.74) but not with baseline BMD or changes in BMD at the total hip, lumbar spine or total body (p>= 0.064 for all sites). Use of more than one and use of enzyme-inducing anticonvulsants were significantly associated with total fractures (HR 1.55 (1.15, 2.09) and (HR 1.36 (95% CI 1.09, 1.69) respectively.

Conclusion:

After adjustment for potential confounders, users of anticonvulsants had an increased risk for total fractures and site specific fractures including hip, clinical vertebral and wrist fractures. The association of anticonvulsant use with fractures was stronger with use of more than one anticonvulsant, and use of enzyme-inducing anticonvulsants. Whether the association of anticonvulsants with fractures is a function of the drug itself or rather, the condition it is being prescribed for merits further study. In clinical practice, however, postmenopausal women who use anticonvulsants should be considered at increased risk for fracture, and attention to fall prevention in these women may be particularly important.

To cite this abstract, please use the following information:
Carbone, Laura, Johnson, Karen, Robbins, John, Larson, Joseph, Curb, J. David, Watson, Kathleen, et al; Anticonvulsant Use, Falls, Fractures and BMD: Findings From the Womens Health Initiative [abstract]. Arthritis Rheum 2009;60 Suppl 10 :611
DOI: 10.1002/art.25691

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