Abstracts

Rationale: Antiepileptic treatment can alter body weight. Excess body weight has important implications for appearance of future co-morbid diseases. Body weight, skin fold thickness and body mass index offer crude estimation of body fat content and are influenced by many factors including muscle mass and weight of body organs. Bioelectrical impedance analyses are reasonable estimates for trends in body fat but are poor in measuring absolute body fat content. DEXA offers a new, non-invasive, simple and accurate determination of absolute body measurement. We utilized a DEXA technology to measure absolute body fat in children exposed to valproate, carbamazepine or lamotrigine monotherapy. Methods: 50 children (20 girls and 30 boys) ages 5-18 years exposed to montherapy with either valproate, carbamazepine or lamotrigine monotherapy had whole body fat measured using DEXA. Children exposed to other medication other than monotherapy AED were excluded. Diet, activity and exercise logs were maintained. Institutional IRB consent and assent was obtained. Results: Absolute body fat measures were highest for valproate (16.5kg) and higher than those receiving carbamazepine (14.1kg) and significantly higher than those receiving lamotrigine (9.2kg) P<0.05. As expected, body fat increased with age, however, all three groups were of similar ages, mean ages VPA=12.6 yrs, LTG=12.2 yrs and CBZ=12 yrs. Duration of therapy was longer for VPA (5.2 yrs) compared to CBZ (5 yrs) and LTG (4 yrs). Gender also influenced body fat content. There were more boys treated with VPA compared to CBZ and LTG, however, the body fat relationship was maintained even after correcting for age, gender and duration of therapy. Bivariate analysis of fat by age was higher for VPA compared to CBZ or LTG (VPA R2=0.5 compared to LTG R2=0.25 and CBZ R2=0.24). Conclusions: Correcting for gender and age, children exposed to valproate monotherapy on average had >70% more absolute body fat content than those treated with lamotrigine and 17% higher compared to carbamazepine. This difference was seen after exposure to 4 years of monotherapy. Increased body fat raises concerns for future increases in the risk of heart disease, cancer, and Type 2 diabetes.