Effects of cross-sex hormone treatment on transgender women and men.

OBJECTIVE: To describe weight, body mass index (BMI), blood pressure (BP), lipids, and hormone levels in transgender women and men presenting for initiation of cross-sex hormone therapy at a community clinic in the United States.

METHODS: Twenty-three transgender women (persons assigned male at birth who identify as female and want to use estrogen to develop female secondary sex characteristics) and 34 transgender men (persons assigned female at birth who identify as male and want to use testosterone to develop male secondary sex characteristics) presenting for initiation of hormone therapy at a community health center were enrolled. Body mass index, BP, lipids, and sex hormone levels were measured at baseline and 6 months. Persistence of menses at 6 months in transgender men was recorded.

RESULTS: Sixteen transgender women and 31 transgender men completed the study. Baseline and 6-month median BPs and lipid values were within a normal clinical range. Median systolic BP in transgender women dropped from baseline 130.5 mmHg (interquartile range 11.5) to 120.5 mmHg (interquartile range 15.5) at 6 months (P=.006). Testosterone levels remained elevated in 33% and estradiol (E2) levels were supratherapeutic in 19% of transgender women at 6 months. Median BMI for transgender men was 29.1 kg/m (interquartile range 11.2) at baseline and 30.0 kg/m (interquartile range 11.4) at 6 months (P=.024). Six-month total testosterone levels were subtherapeutic in 32% and E2 levels remained elevated in 71% of transgender men.

CONCLUSION: In transgender women, estrogen therapy, with or without antiandrogen therapy, was associated with lower BP. In transgender men, testosterone therapy was associated with increased BMI. The study had insufficient power to detect other associations. Monitoring of hormone levels to guide therapy appears to be useful.

LEVEL OF EVIDENCE: III.