Endocrine Abstracts

The sex-specific sex steroid profile seems to be associated to the gender differences between males and females on metabolic and cardiovascular risk (CVR). Objetive: to examine the effects of cross-gender sex steroid exposure on metabolic and CVR parameters. We incorporated 152 women transgender (WT), age (Median) 31 yr old (16–62) and 76 male transgender (MT) age: 25 yr old (17–53), treated at least by 1 year. WT received transdermal 17ßEstradiol (E2) 50 μg/day+cyproterone acetate (up to 50 mg/day) and MT received transdermal Testosterone (T) 5 g/day or T-undecanoate (1000 mg i.m./12 weeks). Waist and hip circumference, BMI, T, E2, lipids, glucose, insulin and HOMA index, were measured at baseline and after 1-year of treatment. Group WT: No changes in the anthropometric variables were detected. T decreased from 5.1±2.3 to 0.96±1.4 ng/ml, P<0.0001. E2 and prolactin increased: 38±18.8–196.7±21 pg/ml, P<0.0001 and 19.8±19.7–27.9±17.3 ng/ml, P<0.01 respectively. HDL-c increased (49.5±11.9–54.7±15.1 mg%, P<0.02) while insulin and HOMA index decreased: 8.9±6.3 vs 8.1±3.8 uU/ml, P<0.02 and 2.14±1.7 vs 1.9±1.0, P<0.01, respectively. Group MT: T induced an increment in BMI (24.8±6.1–25.7±5.3, P<0.013), in ratio waist/hip (0.86±0.08–0.89±0.08, P<0.05), in T (0.44±0.19–5.8±3.1 ng/ml P<0.0001), and in HOMA index (1.69±1.0–2.37±1.27 P<0.03), while E2 and HDL-c decreased (6.8±79–65.2±37.7 pg/ml P<0.0001 and 59.7±13.6–52.7±12.7 P<0.02, respectively). Prolactin remains unchanged (19.3±8.3–17.3±6.8 ng/ml). There were significant correlations (Pearson) between the percentage increment of HOMA index and increment of both waist circunference (r: 0.438, P<0.037) and serum testosterone (r: 0.559, P<0.03). In this large number of transgender population treated with similar dosis and drugs, E2 seems to be protective (improvement of insulin-resistance and lipid profile) while T administration to biological women induced deletereous changes on lipid and insulin-resistance parameters.

These results seems to support the hypothesis that estrogens have beneficial effects in men and women but the dual action of T (in genetically men and women) seems to be associated to a gender-specific effect.