ESPE Abstracts

Background: Male to female (MtF) gender dysphoric adolescents with advanced pubertal development can be treated with antiandrogenic progestins such as cyproterone acetate (CA). CA is much cheaper and easier to administer than GnRHa and can later be combined with cross-sex hormones (17β-estradiol) (CA+E). To date, few data exist on the (side) effects of progestins for this indication.

Objective and hypotheses: To report the effects of consecutive CA and CA+E in MtF adolescents on antropometrics, biochemical, hormonal parameters and side effects.

Method: Retrospective analysis of clinical and biochemical data in 27 MtF adolescents treated with CA monotherapy for 11 months and CA+E for 12 months. Statistical analysis: Shapiro-Wilk, paired Student-T or Wilcoxon signed-ranks test (as appropriate). All participants were advised to take vitamin D supplements and a calcium-enriched diet.

Results: Most patients reported a reduction in facial shaving (CA:54.2%, CA+E:62.5%). Breast development was induced by CA monotherapy in 28% (B2-3), reaching B3-4 in 77.8% during CA+E. Side effects (breast tenderness, emotionality, fatigue, flushes) were reported during CA in 36% and during CA+E in 66.6%. Hemoglobin, hematocrit and creatinin levels reached the female reference range under CA and remained stable thereafter. Transient (limited) elevation of liver enzymes was noted in four adolescents. HDL/LDL ratio became more unfavourable during CA, but restored with addition of E; glucose metabolism was unaffected. Androgens (total and free testosterone, DHEAS, androstenedione) decreased under CA, with a further decrease during CA+E. Estradiol, SHBG and inhibine B decreased during CA but increased during CA+E. Prolactin levels increased under CA.

Conclusion: CA is effective in suppressing endogenous hormones and initiating feminisation within the first six months of treatment. Furthermore, it is safe and inexpensive. Addition of estrogens are needed for further feminisation.