A NEW prospective study found that 12 months of gender-affirming hormone therapy (GAHT) shifts levels of Cardiac Troponin I in transgender adults toward their affirmed gender, suggesting potential effects of GAHT on cardiac mass or function.
Evaluating Heart Biomarkers in Transition
Cardiac Troponin I, a protein used to detect cardiac injury, predicts cardiovascular events even when within normal limits. Because men generally show higher levels due to greater heart muscle mass, current guidelines recommend sex-specific reference ranges. Yet until now, there has been uncertainty about which cutoff values apply to transgender people receiving hormone therapy.
To address this knowledge gap, researchers in Australia followed 152 adults (transgender and cisgender) over a 12-month period, assessing Cardiac Troponin I alongside testosterone and oestradiol levels.
Hormone Changes and Cardiac Troponin I
In transgender women, oestradiol increased while testosterone fell sharply, accompanied by a decrease in Cardiac Troponin I that aligned more closely with cisgender women (ratio of geometric means = 2.24; P = 0.21) but significantly lower than cisgender men (RGM = 0.22; P = 0.01). Conversely, transgender men experienced higher testosterone and lower oestradiol, with Cardiac Troponin I levels approaching cisgender male ranges (RGM = 0.56; P = 0.32) but remaining well above those of cisgender women (RGM = 7.39; P = 0.003).
These results suggest that Cardiac Troponin I levels evolve with gender-affirming therapy, potentially linked to changes in cardiac mass or ventricular function. The findings build upon previous cross-sectional research by providing longitudinal evidence in healthy adults.
Clinical Implications for Gender-Specific Ranges
By demonstrating measurable changes after one year of therapy, this study supports using affirmed gender reference ranges for interpreting Cardiac Troponin I after 12 months of GAHT. Clinicians should consider these biomarker patterns when assessing cardiac risk or diagnosing myocardial injury in transgender patients. Future work incorporating imaging and longer-term follow-up could clarify the structural mechanisms driving these shifts and refine cardiovascular monitoring practices.
Reference
Cheung AS et al. High-sensitivity cardiac troponin I following gender-affirming hormone therapy in transgender adults. JAMA Netw Open. 2025;8(10):e2537205.
