Bone mineral metabolism changes in epileptic children receiving valproic acid

Abstract

OBJECTIVE: The aim of this study was to evaluate bone mineral density (BMD) in epileptic children receiving valproic acid (VPA) and to determine differences between osteopenic and non-osteopenic children. METHODS: Thirty-three epileptic children, receiving VPA for at least 6 months, were compared with 33 healthy children for BMD. BMD was measured by dual-energy X-ray absorptiometry at lumbar vertebrae, femoral neck and greater trochanter. Serum calcium, phosphorus, alkaline phosphates, osteocalcin and VPA levels were also determined. RESULTS: Patient's osteocalcin levels were significantly higher (P = 0.02) and femur and trochanter BMD values were significantly lower (P = 0.04 and P = 0.03, respectively). Duration of VPA therapy was significantly longer and doses of VPA were significantly higher in seven osteopenic patients compared with 26 non-osteopenic patients. Osteopenic patients (4.6 +/- 2.4 years) were younger than non-osteopenic patients (7.8 +/- 3.2 years) (P = 0.01). CONCLUSION: Long-term and high dose VPA therapy may cause osteopenia, primarily in younger epileptic children. These patients should be followed closely by BMD measurements.