Endocrine Abstracts

Introduction: Anti-epileptic drugs (AED) adversely affecting bone health. However, individual variations between different AEDs exist and not all AEDs are equally toxic to the bone. There is almost equipoise about the effect of valproate on bone.

Methods: We conducted a cross-sectional study assessing bone mineral density with dual energy X-ray absorptiometry at the hip and lumbar spine in 33 outpatients receiving valproate for ≥1 year and 36 healthy adults. Plasma total calcium, phosphate, intact parathyroid hormone, total alkaline phosphatase and 25 hydroxy vitamin D were determined in both groups. All participants were evaluated for daily dietary calcium intake by dietary recall method.

Results: Patients had taken 1020±575.06 g (cumulative dose) of valproate over 6.46±3.83 years of epilepsy. The mean (±S.D.) bone density in patients, as compared to controls, treated with antiepileptic drugs was 0.987±0.121 vs 0.940±0.094 g/cm² at the spine and femoral neck 0.858±0.146 vs 0.818±0.136 g/cm^2.. Difference between two groups was not significant statistically. Osteopenia was present in 90.62% of controls and 85.71% of controls. Osteoporosis was present in 6.25% of patients and 14.29% of controls. Serum intact parathyroid hormone was significantly higher in patients (60.32±29.16 vs 45.16±20.00 pg/ml, P=0.01), but the total calcium, 25-hydroxy vitamin D, alkaline phosphatase and dietary intake of calcium did not differ significantly between patients and controls. But, both groups displayed grossly low serum vitamin D (patients: 12.44±9.91 ng/dl, controls: 13.87±8.57 ng/dl) and dietary calcium intake below recommended daily allowance.

Conclusion: Our results suggest that chronic therapy with valproate does not result in significant decrease in bone density. Widespread vitamin D deficiency is still prevalent in our country.