Short-term patterns of pulsatile luteinizing hormone secretion do not differ between male-to-female transsexuals and heterosexual men.

This study tested whether there is a difference in the pulsatile LH secretion between male-to-female transsexuals and eugonadal heterosexual men. The mean serum LH concentrations, the LH pulse frequency, and the LH pulse amplitude were compared between a group of eight male-to-female transsexuals and a group of 22 heterosexual men. Blood samples for LH determinations were collected every 10 min for seven hours. 17-beta-estradiol and testosterone were measured at the beginning of each test. There were no significant differences between the heterosexual and transsexual group in LH pulse frequency (3.9 +/- 1.3 vs. 3.9 +/- 1.7), LH pulse amplitude (3.7 +/- 1.3 U/l vs. 3.0 +/- 0.5 U/l), mean serum LH concentration (5.2 +/- 1.4 U/l vs. 5.4 +/- 1.1 U/l), 17-beta-estradiol (0.07 +/- 0.01 nmol/l vs. 0.08 +/- 0.02 nmol/l), or testosterone (22.9 +/- 3.7 nmol/l vs. 21.8 +/- 8.0 nmol/l). We conclude that the pulsatile release characteristics of LH do not allow a distinction between eugonadal heterosexual men and eugonadal male-to-female transsexuals.