title: Bone Mineral Changes in Epilepsy Patients During Initial Years of Antiepileptic Drug Therapy.
abstract: Antiepileptic drug (AED) therapy is associated with decreased bone mineral density; however, the time course for this development is unclear. The aim of this study was to evaluate bone mineral changes during the initial years of AED therapy in AED-naive, newly diagnosed epilepsy patients compared with non-AED users. In 49 epilepsy patients newly started on AEDs and in 53 non-AED users of both genders, bone mineral density (BMD) and bone mineral content were measured using dual-energy X-ray absorptiometry at baseline (within the first year of therapy) and at least 1 yr later. Bone changes between the 2 assessments, adjusted for age, height, and weight, were calculated as the annual rate of change. The median duration of AED therapy was 3.5 mo at baseline and 27.6 mo at follow-up. No overall difference was found in mean BMD and bone mineral content measures between user and nonuser cohorts in both cross-sectional baseline and the annual rate of change (p > 0.05). However, users on carbamazepine monotherapy (n = 11) had an increased annual rate of total hip (-2.1% vs -0.8%, p = 0.020) and femoral neck BMD loss (-2.1% vs -0.6%, p = 0.032) compared to nonusers. They also had a marginally higher rate of femoral neck BMD loss (-2.1%, p = 0.049) compared with valproate (-0.1%, n = 13) and levetiracetam users (+0.6%, n = 13). During the initial years of AED treatment for epilepsy, no difference was found in bone measures between AED users as a group and nonuser cohorts. However, the data suggested that carbamazepine monotherapy was associated with increased bone loss at the hip regions, compared to users of levetiracetam or valproate and nonusers. Larger studies of longer duration are warranted to better delineate the bone effects of specific AEDs, with further consideration of the role of early dual-energy X-ray absorptiometry scanning and careful AED selection in potentially minimizing the impact on bone health in these patients.
authors.affiliation: Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Victoria, Australia; Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Baemisla
authors.initials: B
authors.lastname: Shiek Ahmad
authors.affiliation: Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Terence John
authors.initials: TJ
authors.lastname: O'Brien
authors.affiliation: Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Victoria, Australia; Melbourne EpiCentre, The Royal Melbourne Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gorelik
authors.affiliation: School of Physiotherapy and Exercise Science, Curtin University, Western Australia, Australia.
authors.forename: Keith David
authors.initials: KD
authors.lastname: Hill
authors.affiliation: Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Victoria, Australia; Bone and Mineral Medicine, The Royal Melbourne Hospital, Victoria, Australia. Electronic address: jdwark@unimelb.edu.au.
authors.forename: John Dennis
authors.initials: JD
authors.lastname: Wark
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects*; D003430:Cross-Sectional Studies; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged
chemical_list: D000927:Anticonvulsants
keywords: Antiepileptic drugs; bone mineral density; dual-energy X-ray absorptiometry (DXA); epilepsy/seizures; longitudinal study