Evaluation of bone mineral density in adult epileptic patients treated with valproate

There is increasing evidence that chronic treatment with antiepileptic drugs is associated with changes in bone metabolism, increasing the risk of fractures in patients with epilepsy. A few studies have investigated the effect of valproic acid on the bone metabolism and bone mineral density, and there are conflicting results regarding the effect of valproate on the bone mineral density with the majority of studies suggesting that valproic acid reduces bone density.

To evaluate the effect of long-term Valproate monotherapy on bone mineral density and bone biomarkers.

A case-control study was conducted in forty epileptic patients (22 females and 18 males) on a long-term valproic acid therapy. The control group included forty (22 females and 18) apparently healthy volunteers.

Bone mineral density was measured by dual energy x-ray absorptiometry scan at the lumbar spine (L1–4) and blood samples were obtained for all subjects, and analyzed for total serum calcium, phosphate, vitamin D level and parathyroid hormone.

We found a decrease in the bone mineral density T score (osteopenia and osteoporosis) of epileptic group is about 22.5% compared with its percentage in the control group which is 7% only.

We found significantly lower vitamin D level in epileptic group compared with control group (52.5% for epileptic group versus 30% for the control group; including both deficiency and insufficiency).

Bone mineral density Z-and T-score of the lumber spine in adult epileptic on long-term valproic acid therapy was decreased as compared with age-and sex-matched controls; this result was inversely correlated with the dose and duration of valproic acid therapy.