High dose estrogen treatment increases bone mineral density in male-to-female transsexuals receiving gonadotropin-releasing hormone agonist in the absence of testosterone.
OBJECTIVE
To study the effect of estrogen (E) on the male skeleton in the absence of testosterone (T).


METHODS
Retrospective analyses of 40 middle-aged transsexuals treated with subcutaneous injections of gonadotropin-releasing hormone agonist every 4 weeks and oral 17-beta-estradiol-valerat 6 mg/day over two years until reassignment surgery.


METHODS
The bone mineral density (BMD) in the femoral neck and lumbar spine (L2-L4) was measured with dual-energy X-ray absorptiometry at the beginning of cross-sex hormone treatment, after 12 and 24 months, and serum T, E, sex hormone-binding globulin (SHBG), calcitonin (CAL), osteocalcin (OSC), and urinary free deoxypyridinoline (DPD) were measured.


RESULTS
After 12 months, a significant increase in BMD in the lumbar spine from 1.2 to 1.234 g/cm2 and after 24 months to 1.274 g/cm2 was observed. There was a significant increase in BMD in the femoral neck area from 1.068 to 1.109 g/cm(2) after 24 months. There was a significant decrease in serum T levels from 18.65 to 0.57 nmol/l after 12 months, and to 0.62 nmol/l after 24 months, a significant increase in SHBG levels from 50.09 to 125 nmol/l after 12 months, and to 130 nmol/l after 24 months, and a significant increase in serum E levels from 73.42 to 881.6 pmol/l after 12 months, and to 923.62 pmol/l after 24 months of cross-sex hormone treatment. Serum levels of CAL, OSC and urinary DPD were unchanged.


CONCLUSIONS
We conclude that high dose E treatment is able to increase BMD significantly in the femoral neck and lumbar spine independently of serum T levels in middle-aged men. There is no risk of osteoporosis developing in male-to-female transsexuals receiving GnRHa when there is an adequate E substitution.
Department of Obstetrics and Gynecology, Erlangen University Hospital, Universitätsstrasse 21-23, D-91054 Erlangen, Germany. andreas.mueller@gyn.imed.uni-erlangen.de
Andreas
A
Mueller
Ralf
R
Dittrich
Helge
H
Binder
Werner
W
Kuehnel
Theodoros
T
Maltaris
Inge
I
Hoffmann
Matthias W
MW
Beckmann
D000328:Adult; D015415:Biomarkers; D015519:Bone Density / Q000187:drug effects*; D004967:Estrogens / Q000008:administration & dosage*; D005260:Female; D005272:Femur Neck; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists*; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D013739:Testosterone / Q000097:blood*; D014189:Transsexualism / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology
D015415:Biomarkers; D004967:Estrogens; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone