Thrombotic risk associated with gender-affirming hormone therapy

Area of Science:

• Endocrinology
• Hematology
• Transgender Health

Background:

• Transgender and gender-expansive (TG) individuals often experience gender dysphoria, impacting health.
• Gender-affirming hormone therapy (GAHT) is a key intervention for managing gender dysphoria.
• Estrogen and testosterone are primary hormones used in GAHT for feminization and masculinization, respectively.

Purpose of the Study:

• To review alterations in hemostatic parameters due to exogenous estrogen and testosterone.
• To summarize current knowledge on thrombosis risk associated with GAHT in TG populations.
• To highlight knowledge gaps for hematologists managing TG patients.

Main Methods:

• Literature review of studies on hemostasis and thrombosis risk with exogenous estrogen and testosterone.
• Analysis of changes in prothrombotic factors, coagulation inhibitors, hemoglobin, and hematocrit.
• Examination of thrombosis risk in cisgender and transgender populations using these hormones.

Main Results:

• Estrogen use in cisgender women increases prothrombotic factors and thrombosis risk.
• Transgender women on estrogen appear to have an elevated risk of arterial and venous thrombosis.
• Testosterone use increases hemoglobin and hematocrit, potentially raising thrombosis risk, though study results are mixed.

Conclusions:

• GAHT involving estrogen and testosterone significantly impacts hemostatic parameters.
• Understanding these hormonal effects is crucial for assessing and managing thrombosis risk in TG individuals.
• Further research is needed to clarify mixed findings, particularly for testosterone therapy.