Lack of valproic acid-associated weight gain in prepubertal children.

We evaluated whether prepubertal children treated with valproic acid did not gain excessive weight. This retrospective study of children with epilepsy, aged <12 years at enrollment, examined weight gain associated with valproic acid or carbamazepine monotherapy. There was no significant difference between the valproic acid (n = 31) and carbamazepine (n = 49) treated groups in average duration of therapy or mean age. Body mass index scores at the beginning and end of the study were used to evaluate weight gain, while compensating for gains in height. For valproic acid, the linear mixed model detected no gain in body mass index z-scores over time (T = 0.25, DF = 17.3, P = 0.80), though it detected a significant gain in body mass index z-scores for carbamazepine (T = 2.32, DF = 36.7, P = 0.02). Results for McNemar chi-square tests were similar. No significant proportion change occurred among children on valproic acid (chi(2) = 2.0, P = 0.15), whereas a significant increase in the proportion of overweight children occurred on carbamazepine (chi(2) = 4.5, P = 0.03). We detected no excessive weight gain for children on valproic acid, whereas this was demonstrated for a similar socioeconomic group on carbamazepine.