Objective: To investigate the possible role of valproic acid therapy in the development of the weight gain and hyperinsulinemia of epileptic patients.
Methods: The weight and fasting insulin levels were measured in 43 epileptic patients treated with valproic acid (VPA) alone and 39 patients with carbamazepine (CBZ) alone for at last 2 years. The body mass index (BMI) and homeostasis model assessment (HOMA) index were studied in the two groups.
Result: BMI was higher in the VPA-treated group (23.47+/-1.45) than that in the CBZ-treated group (22.27+/-2.10, P<0.05). Fasting insulin level and HOMA index in the VPA group were also higher [(6.64+/-0.79)mU/L and 1.33+/-0.21] than those in the CBZ group [(5.52+/- 0.52)mU/L, P<0.01; 1.15+/-0.12, P<0.01]. While BMI in the VPA group showed no significant correlation with plasma concentration and dose of valproate.
Conclusion: VPA therapy is associated with significantly greater weight gain and hyperinsulinemia, suggesting development of insulin resistance.