Endocrine effects of valproic acid therapy in girls with epilepsy: a prospective study

It is controversial whether the endocrine dysfunction in epilepsy patients is caused by the epilepsy itself, the antiepileptic therapy, or both. We prospectively evaluated the long-term impact of valproic acid monotherapy compared to other anti-epileptic drugs on anthropometric, metabolic, hormonal, and ultrasonographic parameters in girls with epilepsy.

Fifty-seven female patients with epilepsy who had started therapy at mean age of 11.5 ± 3.3 years, 42 with valproic acid (mean dose 13.1 ± 7.0 mg/kg/day and 15 with other anti-epileptic agents were followed for a mean of 3.2 years (range 1.0-8.5 years) in our center. Clinical, hormonal and transabdominal pelvic ultrasound data were collected at 3 time points: before and 6-12 months after onset of anti-epileptic drug treatment; and at the last visit while patients were still taking anti-epileptic drugs.

There were no significant between-group differences regarding changes in height, body mass index standard deviation score, levels of glucose and insulin, or lipid and endocrine profile from first to last visits. Mean thyroid-stimulating hormone level increased significantly between first and last visit only in the valproic acid group (p < 0.001), with no significant difference in free T4 level over time or between groups. The rate of clinical polycystic ovary syndrome for the valproic acid group (11%) was comparable to that reported in healthy controls (5-10%).

Administration of valproic acid had no adverse effect on body weight, metabolic status or endocrine function over an average follow-up of 3.2 years. Valproic acid appears to be safe for use in girls with epilepsy.