Cardiovascular function in transgender women on hormone therapy: the role of circulatory Power, Rate-pressure product, and blood pressure responses to exercise

Introduction Gender-affirming hormone therapy (GAHT) may influence cardiovascular physiology in transgender women, but its impact on hemodynamic responses to exercise remains unclear. This study investigated circulatory power (CircP), rate-pressure product (RPP), and blood pressure (BP) responses during maximal exertion in transgender women compared with cisgender women and cisgender men. Methods This cross-sectional study included 51 physically active individuals (17 transgender women on GAHT for 8.1 ± 3.7 years, 17 cisgender women, 17 cisgender men), matched by age and aerobic fitness. Participants underwent maximal cardiopulmonary exercise testing (CPET). Systolic and diastolic BP were measured at rest, at the first ventilatory threshold (VT1), and at peak. CircP was defined as peak oxygen uptake (VO2) × systolic BP, and RPP as heart rate (HR) × systolic BP. Between-group differences were assessed with Analysis of Variance (ANOVA) and Bonferroni correction, and Analysis of Covariance (ANCOVA) was adjusted for hypertension. Results Transgender women exhibited significantly lower CircP than cisgender men (Δ = −2528.2; p < 0.001; η2 = 0.287) and similar values to cisgender women (Δ = −345.1; p = 1.000). Peak systolic BP was lower in transgender women (180.3 ± 20.1 mmHg) versus cisgender men (200.3 ± 32.2 mmHg; p = 0.025), despite comparable peak VO2 and HR. At VT1, transgender women resembled cisgender men in systolic BP but differed from cisgender women. RPP followed a similar gradient, with transgender women intermediate, but group differences were not significant after adjustment (p = 0.123; η2 = 0.089). Diastolic BP differed at VT1 but not at peak. Hypertension did not significantly affect CircP. Conclusion transgender women under GAHT demonstrate consistently lower CircP and attenuated systolic BP responses during exercise, suggesting a distinct cardiovascular adaptation. CircP showed stronger discriminatory power than RPP, supporting its role as a sensitive marker. CPET may assist functional evaluation and cardiovascular risk stratification in gender-diverse populations.