THE EFFECT OF ANTICONVULSANT MEDICATION ON BONE MINERAL DENSITY AND OSTEOPOROSIS - A TWIN AND SISTER STUDY
Abstract number :
F.05
Submission category :
Year :
2003
Submission ID :
3597
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Sandra Petty, Lynda Paton, Terence J. O[apos]Brien, Christine Kilpatrick, John Wark The Department of Neurology, The Royal Melbourne Hospital, Parkville, Victoria, Australia; The Department of Medicine, RMH, The University of Melbourne, Parkville, Victori
Studies of the effect of anti-epileptic drugs (AEDs) use on bone mineral density (BMD) and the risk of osteoporosis have been limited by inadequate controls, use of cross sectional design, and lack of adjustment for other BMD determinants. In this study we utilized the University of Melbourne [italic]Twin and Sister Longitudinal Bone Health Study[/italic] to investigate this issue further. The twin/sister paired design of this study controls for genetic and environmental factors that have confounded previous studies addressing this issue.
Participants with epilepsy or AED use were identified from the database. Bone mineral density (BMD, g/cm2) was measured at the lumbar spine (LS), total hip (TH), femoral neck (FN) and 1/3 distal radius (FA). Total body bone mineral content (TB BMC, kg), fat mass (kg) and lean mass (kg) were calculated. Results were expressed as the within-pair percentage difference, relative to the non-user. All data were adjusted for age, height and weight.
Nineteen pairs (9 monozygous and 6 DZ dizygous) and 4 sibling pairs ([lt] 3 years age difference) were assessed mean (SD) age of 38.97 (14.12) years (range 18 - 66 years). Pairs were discordant for AED use, with one having [gt]12 months AED use (user) and the other no exposure (non-user), except for 1 pair that was discordant for dose. On baseline measures there was a significant within-pair difference in BMD at TH (-6.08%, p = 0.035), FN (-5.29 p = 0.048), FA (-3.97%, p = 0.036) and TB BMC (-5.18 (0.029) and a trend for LS BMD (-5.32 (0.083). 6/19 (32%) AED users vs. 2/19 (11%) non-users had a TH z-score [lt] -1.5 indicating increased risk of fracture for age.
The findings using a matched twin-sister approach indicate that patients with a history of AEDs use have significantly lower BMD at clinically relevant sites for fracture risk. Monitoring of BMD may be important in patients taking long-term AED therapy.