Sex-specific responses of central artery stiffness to cold pressor test-mediated sympathetic activation.

Considerable attention has been devoted to investigating whether acute activation of the sympathetic nervous system, triggered by daily life stressors, increases central artery stiffness (CAS). Overt sex differences in sympathetic neurovascular transduction lead to distinct cardiovascular responses to sympathoexcitation in men versus women. Our study aimed to determine if the cold pressor test (CPT), chosen to simulate highly painful stressors individuals encounter daily, would induce CAS augmentation in a sex-balanced cohort of young individuals and whether any observed CAS increase would differ between sexes. Twenty-eight participants (14 men, 14 women) provided baseline and CPT measurements of carotid-femoral pulse wave velocity (cf-PWV), mean arterial pressure (MAP), cardiac output (CO), total peripheral resistance (TPR), and heart rate (HR). CPT involved immersing participants' feet in 5 °C ice-water slurry. Data were analyzed using 2-way analysis of variance and post hoc testing, where applicable. CPT significantly increased (p < 0.01) cf-PWV values in our population, with women showing lower collective CAS values compared to men across baseline and CPT conditions. CPT augmented (p < 0.01) MAP, HR, and CO without altering stroke volume (SV), but increased (p = 0.002) TPR only in men. Men collectively exhibited higher (p < 0.01) CO and SV values across baseline and CPT conditions, as well as lower (p < 0.01) TPR values compared to women. These results support the notion that CPT increases CAS in a healthy young population. Despite observed sex differences in peripheral vascular responses to CPT, these variances did not differently impact the central pressor response or central artery stiffening between sexes. Given the well-documented sex differences in cardiovascular risk and incidence, these findings deepen understanding of how cardiocirculatory responses differ between sexes under stress. These findings support sex-specific approaches in cardiovascular medicine and prevention, including tailored coping strategies for managing stress.