Endocrine Abstracts

Background: Male-to-female transsexual persons use estrogens + antiandrogens to adapt their physical bodies to the female sex.Estrogens are powerful stimulators of synthesis and release of prolactin and serum prolactin levels are usually somewhat increased following estrogen treatment.

Objective: To determine prolactin levels and to assess the risk of development of prolactinoma in male-to-female transgender subjects following cross-sex hormone therapy (CHT).

Materials and methods: Retrospective longitudinal study including all male-to-female transsexual persons assisted in the Gender Identity Unit from 2015 to 2017.Clinical and laboratory data were collected before and after a mean duration of CHT of 24 months.Radiologic examinations of the pituitary were performed in those patients whose prolactin levels persistently increase despite stable or reduced estrogen levels.Transgender individuals who receive psychotropic medications were excluded.

Results: Thirty-nine male-to-female transsexual persons were included (mean age 29.05±11.63 years). 68.8% with oral estradiol mean doses 17.18±5.74 mg/week, 31.2% estradiol transdermal patch mean doses 45.15±36.85 mg/week and 78.3% plus cyproterone acetate mean doses 52.13±22.99 mg/day.Prior to treatment, prolactin levels (PRL) were 13.97±9.33 ng/ml,estradiol(E2) 43.90±30.27 pg/ml,testosterone(T2) 274.88±215.41 ng/dL, LH 4.78±5.51mUI/ml and FSH 5.16±6.44 mUI/ml.After a mean follow up of 24.7±35.6 months, PRL increased to 23.54±14.19 ng/ml (P=0.02),E2 to 48.89±24.92 pg/ml (P=0.03), T2 dropped to 111.25±160.03 ng/dL (P=0.023), LH to 2.01±3.42 mUI/ml (P=0.021) and FSH to 2.60±4.34 mUI/ml (P=0.025). None prolactinomas were reported.

Conclusion: Transgender females treated with estrogens have elevations in prolactin levels although any case of prolactinoma was reported.Clinicians should measure prolactin levels in transsexual people and perform imaging techniques of the pituitary in those patients with high prolactin levels.