Recovery of the Gonadal Axis in Patients with Prolactinomas

Prolactinomas are the most common functional pituitary adenomas, leading to an increased secretion of prolactin. The symptoms vary and include symptomatic as well as asymptomatic courses. Symptoms are mainly caused by hyperprolactinemia leading to a suppression of the hypothalamic-pituitary-gonadal axis. For individual therapy, planning the knowledge of influencing factors and disease progression is essential. Our goal was to examine the time period as well as the role of other influencing factors until the hypothalamic-pituitary-gonadal axis is normalized under cabergoline-therapy. We retrospectively analyzed the data of patients who were treated at Amedes in Hamburg between 2013 and 2023 from diagnosis to remission. Among initially 410 patients, 66 patients fulfilled all inclusion criteria. This large discrepancy is due to the fact that many patients had already started therapy with cabergoline before their initial endocrinology consultation. As a result, we lacked relevant information on baseline prolactin levels. Diagnosis of the suppressed hypothalamic-pituitary-gonadal axis was made by measuring diminished serum concentrations of luteinizing hormone (women: follicular phase<2.4 mIU/mL, ovulation phase<14.0 mIU/mL, luteal phase<1.0 mIU/mL, and postmenopause<7.7 mIU/mL; men:<1.7 mIU/mL), follicle stimulating hormone (women: follicular phase<3.5 mIU/mL, ovulation phase<4.7 mIU/mL, luteal phase<1.7 mIU/mL, and postmenopause<25.8 mIU/mL; men<1.5 mIU/mL), estradiol (women:<30.9 pg/mL) or testosterone (men: 20-49 y<2.49 ng/mL, from 50 y<1.93 ng/mL). We examined the average time interval until normalization of these concentrations under cabergoline therapy and assessed whether there was a significant correlation between this time interval and other influencing factors. The mean duration until normalization of the hypothalamic-pituitary-gonadal axis under cabergoline therapy was 82 days. The statistical analysis showed a significant correlation between this duration and initial prolactin levels, as well as gender and age. Thus, patients with higher initial prolactin levels, older patients, and men had longer treatment durations. There was no correlation between time period and adenoma size, cabergoline dosage, comedication and accompanying diseases.