Histomorphometry was performed in iliac crest
biopsies from 15 female-to-male (F-M) transsexuals with a mean age of 30 ±
6.1 (SD) years. At the time of study, they had been treated with parenteral
testosterone esters (250 mg/2 weeks) or oral testosterone undecanoate (160
mg/day). The median androgen treatment duration was 39 months. The patients
had undergone hysterectomy and bilateral ovariectomy. The bone biopsy was
obtained after double tetracycline labelling.
Histomorphometric results were compared
with data from 8 postmenopausal women and with data from 11 healthy men who
had died suddenly. Dynamic parameters were compared with data from the
literature. The biochemical picture was characterized by serum testosterone
concentrations lower than in eugonadal men and estradiol concentrations
lower than in eugonadal women and elevated gonadotrophin levels.
The bone mineral density in the F-M
transsexuals was as expected for age (Z-score -0.31 ± 1.49). Cortical
thickness was significantly higher in F-M transsexuals than in both control
groups. Trabecular bone structure was similar in F-M transsexuals and both
control groups.
The bone formation parameters were
generally lower in F-M transsexuals than in the control groups. The eroded
surface was lower in F-M transsexual than in postmenopausal women. The low
bone turnover and preservation of trabecular bone is consistent with the
assumption that testosterone treatment protects bone in these F-M
transsexuals from the deleterious effects of estrogen deficiency.
The increased cortical thickness suggests
an anabolic effect of the testosterone treatment.
Citation:
J Bone Miner Res 1996; 11: 1769-1773
an article published on the Internet by The International Journal of
Transgenderism <http://www.symposion.com/ijt/>