Objective: This study aimed to determine the frequency and factors associated with obesity in a cohort of children and adolescents with newly diagnosed untreated epilepsy.

Methods: Body mass index (BMI) Z-scores and percentiles, both adjusted for age, were used as measures for obesity. Potential covariates associated with these BMI measures included age, etiology (cryptogenic, idiopathic, symptomatic), seizure type (generalized, partial, unclear), concomitant medications (stimulants, nonstimulants, none), and insurance status (privately insured, Medicaid). The primary analysis compared the epilepsy patients' BMI Z-scores to Centers for Disease Control and Prevention data for healthy children. The secondary analysis compared the epilepsy patients' BMI Z-scores to those of a regional healthy control group. Additional analyses incorporated the secondary outcome measure BMI percentiles indexed for age.

Results: Children with newly diagnosed untreated epilepsy had higher BMI Z-scores compared to standard CDC growth charts (p < 0.0001) and the healthy control cohort (p = 0.0002) specifically at both of the 2 tail ends of the distribution. Overall, 38.6% of the epilepsy cohort were overweight or obese (BMI 85th percentile for age). Differences in age, etiology, and concomitant nonepilepsy medications were significantly associated with variability in age-adjusted BMI Z-score. Patients in adolescence had higher adjusted BMI Z-scores than younger patients. Patients with symptomatic epilepsy had lower adjusted BMI Z-scores than patients with idiopathic epilepsy. Patients on stimulant psychotropics exhibited lower adjusted BMI Z-scores than patients on no medication.

Conclusion: Obesity is a common comorbidity in children with newly diagnosed untreated epilepsy and correlates with increasing age, idiopathic etiology, and absence of concomitant medication.