ANTICONVULSANT USE IN ELDERLY WOMEN INCREASES THE RATE OF HIP BONE LOSS
Abstract number :
F.02
Submission category :
Year :
2002
Submission ID :
2551
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
K. E. Ensrud, T. S. Walczak, T. L. Blackwell, P. J. Bowman, E. R. Ensrud, K. L. Stone. Medicine & Epidemiology, VA Medical Center & University of Minnesota, Minneapolis, MN; Research, MINCEP[reg] Epilepsy Care, Minneapolis, MN; Epidemiology & Biostatistic
RATIONALE: Anticonvulsant drug (ACD) use may result in lower bone mineral density (BMD). Available studies are compromised by use of cross sectional design, selection bias, lack of adequate controls, and lack of adjustment for other determinants of BMD. We tested the hypothesis that continuous ACD use in elderly women increases rates of hip bone loss even after adjustment for other determinants of bone loss.
METHODS: We assessed current ACD use using an interviewer-administered questionnaire at the 4th, 5th, and 6th exams in a cohort of 4202 elderly women participating in the Study of Osteoporotic Fractures. We verified use from medication containers and classified type of medication from product brand or generic names obtained from containers using a computerized medication dictionary. We categorized women according to their reported ACD use as continuous users (use at all 3 exams), partial users (use at 1 or 2 exams) or nonusers (no use at any exam). Hip BMD was measured at the 4th exam and an average of 4.4 years later at the 6th exam by dual X-ray absorptiometry. Mean annual percent change in total hip BMD (THBMD) and its 4 subregions was calculated by category of ACD use. All results were adjusted for the following characteristics measured at the 4th exam: age, health status, total calcium intake (dietary plus supplemental), Vitamin D supplement use, estrogen use, body mass index and THBMD.
RESULTS: 40 (0.92%) women were continuous ACD users, 68 (1.6%) partial users and 4094 nonusers. All continuous ACD users took phenytoin, carbamazepine, phenobarbital, or primidone; three took additional valproate. The average rate of decline in THBMD in the overall cohort steadily increased from [ndash]0.70%/yr in nonusers to [ndash]0.94%/yr in partial users to [ndash]1.17%/yr in continuous users (p for trend =0.006). Findings were similar at subregions of the hip, though results reached significance only at the intertrochanteric region.[table1]
CONCLUSIONS: Anticonvulsant use in elderly women is associated with increased rates of hip bone loss, even after adjustment for other determinants of bone loss. Continuous users have the highest rates of loss. Assessment of anticonvulsant use should be included in the clinical evaluation of osteoporosis risk in older women.
[Supported by: grants AG05407, AR35582, AG05394, AR35584 and AR35583 from the Public Health Service.]