OR42-1 Variable Response to Oral Estradiol Therapy in Male to Female Transgender Patients

Program: Abstracts - Orals, Poster Preview Presentations, and Posters
Session: OR42-Disorders of Sex Development and Transgender Medicine
Clinical/Translational
Tuesday, June 24, 2014: 9:30 AM-11:00 AM
Presentation Start Time: 9:30 AM
W185 (McCormick Place West Building)
Matthew C Leinung, MD
Albany Med College, Albany, NY
Objective:  Multiple therapeutic options for male to female (MTF) patients are available and the optimal regimen is unknown. The goal of this study was to characterize the hormonal response to oral estradiol (E2), with and without anti-androgens.

Methods:  Data was analyzed from a prospectively collected database of patients seen in the transgender clinic at our institution.  All MTF seen from 2008 through 2013 were included. The therapeutic approach is to titrate patients up to 4 or 6 mg E2.  Medroxyprogesterone (MP), 2.5 to 10 mg, is added if testosterone (T) levels are not well suppressed.  Spironolactone or finasteride are added primarily to lessen body hair, without regard to T levels. 

Results:  A total of 162 patients were seen. Of these, 36 were just initiating therapy or did not wish to take full dose eE2; 25 had gender reassignment surgery and lacked valid pre-surgical T levels ; and 19 were on Premarin.  This left 82 who had hormone levels measured on E2 doses meant to provide full feminization.  While on 4 mg, 7 of 21 (33%) T levels in 14 patients were suppressed (<100 ng/dL: normal male > 300).  Of the 9 patients not suppressed, 6 went to 6mg but only 2 achieved suppression.  On 6 mg E2, 54 of 112 (48%) testosterone levels in 64 patients were suppressed.  Of 31 patients not suppressed, ten were increased to 8 mg E2.  On this dose, 5 of 16 (31%) T levels were suppressed.   MP was used in 32 patients to help suppress T.  In 1 of 4 (25%) patients on 4mg E2, in 7 of 22 (32%) on 6mg E2, and in 2 of 6 (33%) on 8mg E2 it lead to T suppression.  Measured 17E2 levels (in pg/mL, normal male <44) trended up with increasing doses (means of 111±39, 130±52, and 153±92 on 4, 6, and 8 of E2 respectively) but did not correlate with T suppression.  Overall, 41 of 82 (50%) had suppressed T at their last visit on 4-8 mg E2 with or without MP.  Use of spironolactone (n=25) did not lower T and in fact there was a trend towards higher levels (130± 102 vs 108± 114). Finasteride use (n=45) was associated with higher T levels while on E2 (mean T 178 ±130 vs 107±113).

Conclusions:  Estradiol in doses of 4-8mg daily is able to increase E2 levels significantly but is incompletely effective in suppressing testosterone levels in MTF. The addition of medroxyprogesterone  can bring further suppression, but many patients remain incompletely suppressed. The use of spironolactone and finasteride do not help with T suppression.

Nothing to Disclose: MCL

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