[Changes of body weight and galanin in epileptic children treated with topiramate]

Topiramate is a new broad-spectrum anti-epileptic drug. Decreased body weight and appetite are common side effects of topiramate. The side effect affects the growth and development in children greatly. Little is known about the mechanisms of topiramate-induced weight loss and decreased appetite in children with epilepsy in China and abroad. galanin is one of factors that affect appetite. It is a neuroendocrine peptide and play an important role in the control of appetite and body weight in the mechanism of hormone release. The purpose of this study was to explore the mechanism of topiramate-induced weight loss in children with epilepsy and the relation of weight loss with change of galanin, thereby to provide evidences for improvement of quality of life, compliance to treatment and reduce side effects of growth and development in children with epilepsy.

Totally 61 patients with especial epilepsy were enrolled into this study and the disease was defined by clinical manifestations and electroencephalography (EEG). Among them 32 cases had generalized seizures and 29 had local seizures. Sixteen normal children were enrolled as control group. The patients' age ranged from 0.5 to 14 (4.76 +/- 4.05) years and the patients were instructed to take 0.5 - 1 mg/kg of topiramate per day, with 0.5 - 1 mg/kg every 3 - 5 d increased to maximum of 3 - 8 mg/kg per day. Patients continued receiving the doses for 4 months. All patients' serum galanin levels and body height and weight and hepatic function were detected before and after antiepileptic drugs treatment. The galanin was detected by using radioimmunoassay.

After treatment with topiramate (61 cases) for 4 months, plasma galanin [(22.01 +/- 8.12) pg/ml] declined as compared with baseline [(26.56 +/- 9.35) pg/ml, t = 2.85, P < 0.01] in children with epilepsy. Twenty-two of 61 patients lost weight, their plasma galanin concentration was significantly lower [(26.51 +/- 10.00) pg/ml vs. (20.45 +/- 8.09) pg/ml, t = 2.91, P < 0.01], but there was no significant change in the weight-gained patients (39/61) and control group (n = 16). In children with epilepsy, the mean value of body weight decreased as compared with the pre-treatment values, but the difference was not significant; however, the body-mass index (BMI) was significantly lower than that obtained before treatment (t = 8.628, P < 0.01). Eighteen of 22 patients who lost weight had decreased appetite, but only five of 39 patients who gained weight showed decreased appetite (chi(2) = 28.50, P < 0.001). The mean value of plasma galanin declined after treatment in patients (23 cases) with decreased appetite [(18.35 +/- 7.80) pg/ml vs. (27.28 +/- 6.90) pg/ml, t = 4.84, P < 0.001]; while plasma galanin did not change significantly after treatment in patients (38 cases) without decreased appetite [(24.23 +/- 7.66) pg/ml vs. (26.12 +/- 5.49) pg/ml, t = 1.04, P > 0.05].

Topiramate treatment may lower the body weight and reduce appetite in part of children with epilepsy which may be mediated by the reduced plasma galanin level.