Endocrine Abstracts

Introduction: Most adolescents with GID have no overt functional or phenotypic abnormalities to explain their presentation. Currently all female to male (FtM) persons undergo detailed evaluation of adrenal function. This study aimed to determine whether subtle abnormalities of adrenal were present and what the appropriate investigation schedule should be.

Methods: Over the past 4 years, 55 biological females aged mean age 16.54 years (13.46–18.37) were referred to the UK National GID service and underwent a standard short synacthen test (250 μg), with baseline A4, DHEAS and testosterone measurements. One additional patient with previously known non-classic 21-OH deficiency CAH was excluded. Results were compared with 15 age-matched controls, mean age 16.19 years (15.04–19.87).

Results: Baseline, 30 and 60 min mean 17OH progesterone concentrations were 1.77, 4.24 and 4.31 nmol/l respectively, ranges 1–8.4, 1–12.4, 1.2–10.7, not different from the control group means 2.1, 4.75, and 5.02 at 0, 30, 60 min (ranges 1–4.9, 2.5–7.4, and 1.8–10.9 nmol/l). Parallel cortisol concentrations were 358 (101–975), 738 (206–1228), and 880 (537–1298) nmol/l at 0, 30, 60 min compared with 273 (79–681), 694 (419–1166), and 840 (506–1426) nmol/l in the controls. The one GID adolescent with a baseline 17OHP of 8.4 nmol/l, greater than the normal laboratory range (<6) did not have an exaggerated rise on stimulation and other adrenal androgens were normal.

Conclusion: In this national cohort of FtM GID adolescents, we have not been able to demonstrate any variations, subtle or otherwise in adrenal steroid secretion to differentiate them from the control group or from predicted normal ranges. Baseline adrenal steroid profile may be evaluated but unless the androgens and precursor concentrations are elevated, synacthen testing does not appear to be indicated.