Impact of Transaffirmative Hormone Therapy on Hormonal and Metabolic Parameters in Chilean Transgender Individuals:...

Transgender individuals are becoming increasingly visible and have specific healthcare needs. There is very limited information regarding the metabolic effects of gender-affirming hormone therapy, particularly in Latin American populations.

To evaluate the endocrine and metabolic effects of gender-affirming hormone therapies (GAHT) in transgender individuals in Chile, as well as their safety and achievement of treatment targets.

This ambispective observational cohort study assessed endocrine and metabolic laboratory parameters in transgender individuals over 18 years of age receiving masculinizing or feminizing GAHT over 24 months.

124 individuals met the inclusion criteria (58 transfeminine [TF], mean age 25 years, and 66 transmasculine [TM], mean age 22 years). TF participants had a mean height of 170 cm, weight of 72.9 kg, and BMI of 25 kg/m2; TM participants had a mean height of 161 cm, weight of 71.5 kg, and BMI of 28 kg/m2. Among TF participants, 38% were living with HIV, and 31% were receiving PrEP. Regarding anthropometric and laboratory changes during follow-up, TF individuals showed significant increases in weight (1.5 kg, p= 0.035) and estradiol (42 pg/mL, p= 0.001), and a decrease in testosterone (78 ng/dL, p= 0.014). TM individuals showed significant increases in weight (2 kg, p= 0.02), testosterone (359 ng/dL, p= 0.03), LDL cholesterol (7.4 mg/dL, p= 0.004), and hematocrit (5.8%, p= 0.02), as well as decreases in estradiol (31 pg/mL, p= 0.002), LH (9.2 uIU/mL, p= 0.02), prolactin (3.8, p= 0.009), and HDL cholesterol (7.3 mg/dL, p= 0.026). No changes were observed in blood pressure, and no thrombotic events occurred. Hyperprolactinemia was observed in 48% of TF and 34% of TM participants, with spontaneous resolution in 83% of cases. Polycythemia occurred only in TM individuals (39%), and 5% required a phlebotomy. No participants reported regret or discontinuation related to gender identity.

In our population, GAHT was safe, with no treatment discontinuations due to adverse effects. Transmasculine individuals showed greater variation in the measured parameters.