Abstracts

Rationale: The cornerstones of osteoporosis prevention are calcium, vitamin D and exercise. The contribution of Vitamin D deficiency to Anti-epileptic Drug (AED) induced osteoporosis is unclear. We investigated concurrent Vitamin D1 (D1) status and DEXA bone scan bone mineral density (BMD) to measure the impact of D1 on BMD. Methods: We screened a database of 169 subjects with vitamin D levels to identify 51 patients with both D1 and DEXA results. Only those aged 50 or younger (n=20) were included to minimize impact of age-related osteoporosis. Spearman's rank-sum measure correlated categories of D1 levels (0-10, 11-20, 21-30, 31-40 and 41-50 ng/mL) with BMD. The association of D1 deficiency (normal>20ng/mL) with bone health (normal, osteopenia, osteoporosis) was analyzed by Chi-square/Fisher’s method. Results: The mean age was 35.9(SD 9.4) years with male:female=9:11. Seven patients (35%) had normal DEXA, 11 (55%) had osteopenia and 2 (10%) had osteoporosis. D1 deficiency was present in 16 (50%) patients. D1 deficiency was not associated with a diagnosis of osteopenia/porosis at the hip (p=0.95) or spine (p=0.68). There was no correlation of D1 levels to BMD at the hip (p=0.32), spine (p=0.52) or combined (p=0.27). Conclusions: Our results demonstrate lack of correlation between Vitamin D1 level and osteoporosis in AED-treated young ambulatory patients. We conclude that AED-induced osteoporosis likely involves other pathophysiologic mechanisms in addition to Vitamin-D deficiency. A larger trial is underway to confirm these preliminary observations.