Study objective: To assess the effect of topiramate (TPM) on body mass index (BMI) in paediatric epilepsy patients and to examine predictors of weight loss.
Design: Retrospective, observational study.
Setting: University clinic epilepsy outpatient department.
Subjects: Patients below age 18 years who received TPM for at least 12 months.
Measurements and main results: Changes in BMI (kg/m2) standard deviation scores (S.D.S.) from baseline to the follow-up periods of 12, 24 and 36 months were evaluated. The repeated measures t-test for paired samples, revealed significant decreases for BMI S.D.S. at 12 months (P = 0.004; n = 53) and 24 months (P = 0.044; n = 35), but no significant decrease at 36 months (n = 21). Analysis of variance revealed a predictor value of sex for BMI S.D.S. at 12 months (females more likely to lose weight; P = 0.037) and a predictor value of baseline BMI for BMI S.D.S. at 24 months (patients with a higher baseline BMI were more likely to lose weight; P = 0.047).
Conclusion: Weight loss is common in paediatric epilepsy patients who receive TPM and is sustained for at least one year. The pattern of weight loss differs according to sex and baseline BMI.