Changes in sex steroid levels in women with epilepsy on treatment: Relationship with antiepileptic therapies and seizure frequency

Purpose:   Reproductive dysfunction in epilepsy is attributed to the seizures themselves and also to antiepileptic drugs (AEDs), which affect steroid production, binding, and metabolism. In turn, neuroactive steroids may influence neuronal excitability. A previous study in this cohort of consecutive women with epilepsy showed that patients with more frequent seizures had higher cortisol and lower dehydroepiandrosterone sulfate levels than those with rare or absent seizures. The present study was aimed at evaluating, in these same women, the possible relationship between some clinical parameters, seizure frequency, AED therapies, and sex hormone levels.
Methods:   Estradiol (E2), progesterone (Pg), sex hormone-binding globulin (SHBG), and free estrogen index (FEI) were measured during the luteal phase in 113 consecutive females, 16–47 years old, with different epilepsy syndromes on enzyme-inducing AED (EIAED) and/or non–enzyme-inducing AED (NEIAED) treatments, and in 30 age-matched healthy women. Hormonal data were correlated with clinical parameters (age, epilepsy syndrome, disease onset, and duration), seizure frequency assessed on the basis of a seizure frequency score (SFS), and AED therapies.
Results:   E2, Pg, and FEI were lower, whereas SHBG levels were higher in the epilepsy patients than in the controls. However, sex steroid and SHBG levels were not different between groups of patients categorized according to SFS. Therapies with EIAEDs accounted for changes in E2 levels and FEI.
Conclusions:   Despite globally decreased sex steroid levels in serum, actual hormone titers were not significantly correlated with SFS in consecutive epilepsy women; rather, these hormonal changes were explained by AED treatments, mainly when EIAED polytherapies were given.