ESPE Abstracts

Background: Adolescents presenting with persistent gender dysphoria (GD) may undergo pubertal suspension via the use of GnRH analogues such as triptorelin (Gonapeptyl Depot) to allow further consideration of the dysphoria. Locally, a standard monthly dose of this drug is administered for an initial target duration of 12 months prior to re-assessment.

Objective and hypotheses: The need to obtain full gonadotrophin and sex hormone suppression to ensure accurate decision making is unknown. Should the standard dose be individualised?

Method: Serum LH, FSH, testosterone and oestradiol were measured in 74 adolescents with GD (15–18y) before and after 6 months triptorelin 3.75 mg 4 weekly. Results are presented as medians and undetectable measurements were analysed using the assay’s limit of quantitation.

Results: 25 natal males & 49 natal females were treated initially for a mean of 7 months (range 3–13). Endogenous gonadotrophins were significantly (P<0.0001) reduced in both males (LH by 88%, FSH 64%) and females (LH 94%, FSH 42%). LH was completely suppressed in six females but both LH and FSH were measurable in all other instances. Post-treatment serum testosterone in males was reduced overall by an average of 94% and was undetectable in five patients. In females, testosterone was measurable in 33 of 42 individuals. Serum oestradiol was undetectable in 77% of patients post-treatment but was measureable in one male and 14 females (≤101 pmol/L). There was no correlation between age, duration of treatment, or body surface area with the response to triptorelin.

Conclusion: LH, FSH, testosterone, and oestradiol were all significantly reduced following initial triptorelin treatment. However, LH and/or FSH remained detectable in nearly all adolescents suggesting continued gonadal stimulation. This is supported by measurable testosterone, but not oestradiol, in most subjects. The effect of measurable sex hormones on long term decision making is unclear. The lack of direct correlation with auxologic measurements means greater attention to individual treatment responsiveness is required.