Arterial stiffness and testosterone use in transgender and non-binary adults assigned female sex at birth

Context: Some studies have indicated that transgender and non-binary adults assigned female sex at birth (TNBF) who use testosterone may be at elevated cardiovascular risk. However, the mechanisms which link testosterone use to cardiovascular risk in TNBF adults remain poorly understood. Arterial stiffness, a prognostic indicator of future cardiovascular risk providing clinically relevant insight into arterial structure and function, may be a mechanism mediating elevated cardiovascular risk in TNBF adults. Purpose: We therefore compared arterial stiffness parameters including central blood pressures – central systolic (cSBP), diastolic (cDBP), and pulse pressure (cPP) – and estimates of carotid-femoral pulse-wave velocity (cf-PWV) between TNBF adults using (TNBFT; n=8; age: 25±4ys; body mass index [BMI]: 26±6kg/m2) and not using testosterone (TNBFnoT; n=7; age: 26±9ys; BMI: 23±4kg/m2). Methods: In the 4-hr post-absorptive state following ≥15 minutes of quiet supine rest, participants underwent a 20-minute assessment in which a single cuff oscillometric device (Mobil-o-Graph, IEM) placed on the left arm inflated every 2-minutes to collect 10 repeated measurements of arterial stiffness parameters. This method for quantifying components of arterial stiffness was specifically chosen due to the non-invasive nature of the measurement technique which does not require access to the pelvic region (unlike the commonly used carotid-femoral applanation tonometry technique). Results: Within the TNBFT group, 6 participants self-identified as transgender and 2 as non-binary. The average age at the onset of testosterone use was 20±3yrs (range: 17-26yrs) with an average duration of use of 3±2yrs (range: 0.3-6yrs). Seven participants reported a parenteral route of administration (subcutaneous injection; n=5, intramuscular injection; n=2) and 1 participant reported using a transdermal route of administration (gel formulation). Within the TNBFNoT group, 1 participant self-identified as transgender and 6 as non-binary. Age and BMI did not differ between TNBFT and TNBFnoT (p=0.62 and p=0.24, respectively). Oscillometric-derived cSBP did not differ between TNBFT and TNBFnoT (109±5 vs. 106±5 mmHg, respectively; p=0.21), nor did cDBP (72±6 vs. 69±5mmHg; p=0.37), or cPP (37±4 vs. 36±3mmHg; p=0.59). Likewise, estimated cf-PWV did not differ between TNBFT and TNBFnoT (5.06±0.37m/s vs. 5.09±0.55m/s; p=0.90). Conclusions: Overall, these preliminary data suggest that TNBF adults using testosterone do not present with worsened arterial stiffness relative to TNBF adults not using testosterone, challenging the notion that testosterone use exerts widespread negative effects across the cardiovascular system. Future research may seek to investigate alternative mechanisms (e.g. psycho-socio-cultural factors) which may contribute to cardiovascular risk in TNBF adults. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.