Bisschop Peter H, Toorians Arno W, Endert Erik, Wiersinga Wilmar M, Gooren Louis J, Fliers Eric
Department of Endocrinology and Metabolism, Laboratory of Endocrinology, Academic Medical, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands.
Eur J Endocrinol. 2006 Jul;155(1):11-6. doi: 10.1530/eje.1.02192.
Estrogen and androgen administration modulate the pituitary-thyroid axis through alterations in thyroid hormone-binding globulin (TBG) metabolism, but the effects of sex steroids on extrathyroidal thyroxine (T4) to triiodothyronine (T3) conversion in humans are unknown.
We studied 36 male-to-female and 14 female-to-male euthyroid transsexuals at baseline and after 4 months of hormonal treatment. Male-to-female transsexuals were treated with cyproterone acetate (CA) 100 mg/day alone (n = 10) or in combination with either oral ethinyl estradiol (or-EE) 100 microg/day (n = 14) or transdermal 17beta-estradiol (td-E) 100 microg twice a week (n = 12). Female-to-male transsexuals were treated with i.m. testosterone 250 mg twice a week. A t-test was used to test for differences within groups and ANOVA with post hoc analysis to test for differences between the groups.
Or-EE increased TBG (100 +/- 12%, P < .001) and testosterone decreased TBG (-14 +/- 4%, P = 0.01), but free T4 did not change. Td-E and CA did not affect TBG concentrations. TSH was not different between groups at baseline or after treatment. CA decreased T3/T4 ratios (-9 +/- 3%, P = 0.04), suggesting that T4 to T3 conversion was lower. Testosterone increased T3/T4 ratios (30 +/- 9%, P = 0.02), which probably reflects higher T4 to T3 conversion.
Oral but not transdermal estradiol increases TBG, whereas testosterone lowers TBG. Testosterone increases T3/T4 ratios. Estradiol does not affect T3/T4 ratios, irrespective of the route of administration.
雌激素和雄激素给药通过改变甲状腺激素结合球蛋白（TBG）代谢来调节垂体 - 甲状腺轴，但性类固醇对人体甲状腺外甲状腺素（T4）向三碘甲状腺原氨酸（T3）转化的影响尚不清楚。
我们在基线时以及激素治疗4个月后研究了36名男性变女性和14名女性变男性的甲状腺功能正常的变性者。男性变女性的变性者单独接受醋酸环丙孕酮（CA）100mg/天治疗（n = 10），或与口服炔雌醇（or-EE）100μg/天联合治疗（n = 14），或经皮17β-雌二醇（td-E）每周两次100μg治疗（n = 12）。女性变男性的变性者接受肌肉注射睾酮250mg每周两次治疗。采用t检验来检验组内差异，采用方差分析及事后分析来检验组间差异。
or-EE使TBG升高（100±12%，P <.001），而睾酮使TBG降低（-14±4%，P = 0.01），但游离T4未改变。td-E和CA不影响TBG浓度。治疗前后各组间促甲状腺激素（TSH）无差异。CA使T3/T4比值降低（-9±3%，P = 0.04），提示T4向T3的转化较低。睾酮使T3/T4比值升高（30±9%，P = 0.02），这可能反映了较高的T4向T3的转化。
口服而非经皮给予雌二醇会升高TBG，而睾酮会降低TBG。睾酮会升高T3/T4比值。无论给药途径如何，雌二醇均不影响T3/T4比值。
