Does obesity increase risk of childhood epilepsy?
A new Swedish study in JAMA Neurology looks at the impact of overweight or obesity in early pregnancy on the risk of childhood epilepsy.
The researchers looked at 1,441,623 live single births that occurred at 22 or more completed gestational weeks from January 1997 to December 2011. The Sweden Medical Birth Register and National Patient Register provided the information on epilepsy diagnoses and obesity-related pregnancy and neonatal complications. Following adjustment for maternal age, country of origin, education level, cohabitation with partner, height, smoking, maternal epilepsy, and year of delivery, multivariate Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs).
Of the 1,421,551 children with covariate information, 7592 (0.5%) were diagnosed with epilepsy. Overall incidence of epilepsy in children aged 28 days to 16 years was 6.79 per 10,000 child-years. When compared to offspring of normal-weight mothers (body mass index [BMI] 18.5 to < 25.0), adjusted HRs of epilepsy by maternal BMI categories were overweight (BMI 25.0 to <30.0), 1.11 (95% CI, 1.04-1.17); obesity grade I (BMI 30.0 to <35.0), 1.20 (95% CI, 1.10-1.31); obesity grade II (BMI 35.0 to <40.0), 1.30 (95% CI, 1.12-1.50); and obesity grade III (BMI ≥ 40.0), 1.82 (95% CI, 1.46-2.26).
Rates of epilepsy were significantly increased in children with malformation of the nervous system (adjusted HR, 46.4; 95% CI, 42.2-51.0), neonatal convulsions (adjusted HR, 33.5; 95% CI, 30.1-37.4), and with hypoxic ischemic encephalopathy (adjusted HR, 23.6; 95% CI, 20.6-27.1). Neonatal jaundice was associated with a more than 50% increased risk of epilepsy (adjusted HR, 1.47; 95% CI, 1.33-1.63). Among children with respiratory distress syndrome (adjusted HR, 2.43; 2.21-2.66) and neonatal hypoglycemia (adjusted HR, 2.10; 95% CI, 1.90-2.33), the rates of epilepsy were doubled. Obesity-related pregnancy or neonatal complications could not explain the elevated risk of epilepsy in the children of overweight or obese mothers.
The investigators concluded that childhood epilepsy increases when mothers are overweight or obese, in a dose-response manner. They argued that preventing or reducing obesity could be an important way to reduce the incidence of childhood epilepsy.