Effect of Antiepileptic Drugs on Bone Mineral Density and Bone Metabolism in Epileptic Patients

J Korean Neurol Assoc > Volume 22(4); 2004 > Article

Journal of the Korean Neurological Association 2004;22(4): 310-314.

항간질약물의 복용이 간질 환자의 골밀도 및 골대사에 미치는 영향

박상원, 조용원 허재훈 신용억 이현아 이 준 이 형 임정근 이상도

계명대학교 의과대학 신경과학교실

Effect of Antiepileptic Drugs on Bone Mineral Density and Bone Metabolism in Epileptic Patients

Sang-Won Park

Department of Neurology, Keimyung University School of Medicine, Daegu, Korea

Abstract

Background: Bone mineral density (BMD) is influenced by genetic, hormonal, and environmental factors. Long-term antiepileptic drug (AED) use also causes osteopenia or osteoporosis that have been most extensively described in institutionalized patients. But, the mechanism of these abnormalities is unclear. The objective of this study is to determine the effect of AED on bone density and to explain the pathophysiologic mechanisms by analyzing bone related factors.
Methods: We prospectively examined BMD by dual-energy X-ray absorptiometry in 45 patients with epilepsy. We measured the serum calcium, phosphorus, protein, alkaline phosphatase (ALP), bone specific ALP, vitamin D and osteocalcin to analyze the factors that influence bone metabolism.
Results: BMD was significantly lower in the patient group than in the control group (p<0.05). 13% of patients had osteopenia and 3% of patients had osteoporosis. The level of bone specific ALP was higher in the patient group, but the level of vitamin D was not different, implying that BMD is decreased by the direct effect of antiepileptic drugs. There was a weak negative correlation and marginal significance between BMD and the duration of therapy in the patient group (r=-0.407, p<0.05).
Conclusions: Long-term antiepileptic drug therapy in patients who have seizures causes significant bone loss in the lumbar spine even in the absence of vitamin D deficiency. In addition, the degree of bone mineral density was weakly related with the therapeutic duration of antiepileptic drugs. The regular evaluation of BMD in patients with long-term antiepileptic drugs might be helpful to prevent decreases in BMD. Key Words: Epilepsy, Antiepileptic drugs, Bone mineral density, Osteoporosis, Alkaline phosphatase