OR42-2 Efficacy of Testosterone (T) or Estradiol (E2) Therapy without a GnRH Agonist or Progestin to Suppress Endogenous Gonadal Activity in Transsexual Patients

Program: Abstracts - Orals, Poster Preview Presentations, and Posters
Session: OR42-Disorders of Sex Development and Transgender Medicine
Tuesday, June 24, 2014: 9:30 AM-11:00 AM
Presentation Start Time: 9:45 AM
W185 (McCormick Place West Building)
Lindsey v. Spratt1, Erin Reardon1, Jerrold S. Olshan, MD2 and Toni Eimicke, MS, CPNP2
1Maine Medical Center, Portland, ME, 2The Barbara Bush Children's Hospital @ Maine Medical Center, Portland, ME
Although both the Endocrine Society guidelines and the World Professional Association for Transgender Health agree that suppression of endogenous gonadal function is an important goal of transsexual hormonal therapy, neither endorse specific regimens of hormonal therapy for female-to-male (FTM) or male-to-female (MTF) patients. Both guidelines cite a lack of evidence.  How often a GnRH agonist or progestin is necessary for effective suppression of endogenous gonadal activity has not been reported. We evaluated gonadal suppression with T or E2 alone in 31 adult transsexual patients from our clinic (21 FTM and 10 MTF).  Inclusion criteria were:  1) age 18-40 for FTM and age 18-50 for MTF, 2) normal reproductive function prior to therapy, 3) normal renal and hepatic function, 4) serum free T within the normal adult male range in FTM (at least 10% above lower and 10% below upper limits of normal) and serum E2 100-200 pg/mL in MTF while on therapy and 5) no concurrent therapy with a progestin or GnRH agonist. FTM patients received intramuscular (IM) or subcutaneous ( SC) T cypionate injections and MTF patients received oral E2.  Consistent with Endocrine Society guidelines, effective suppression of ovarian function in FTM patients was assessed by absence of menses and serum E2 <50 pg/mL and testicular suppression in MTF patient was assessed by serum free T within the adult female normal range (1.1-6.3 pg/mL). Serum free T (equilibrium dialysis following determination of total T by tandem mass spectrometry), E2 and LH (MTF) or FSH (FTM) were measured in all patients. All FTM patients were amenorrheic and 18/21 had serum E2 <50 pg/mL (mean 30.0±2.1 SE pg/mL) with T therapy alone. 7/10 MTF patients had serum free T within the normal adult female range (2.3±1.6 SE pg/mL). LH and FSH demonstrated variable degrees of suppression. These results suggest that most transgender patients may not need GnRH agonist or progestin treatment in addition to T or E2 therapy suppress endogenous gonadal activity. Thus, suppression on T or E2 therapy alone should be assessed before adding additional endocrine therapies to suppress ovarian or testicular activity to avoid unnecessary expense or side effects.

Nothing to Disclose: LVS, ER, JSO, TE

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