Gender Difference in Orthostatic Vascular Stiffness Increase in Young Subjects

<b>Background/Objectives:</b> Early detection of increased vascular stiffness in young populations may facilitate the development of more effective strategies for the primary prevention of arterial hypertension and other age-related cardiovascular diseases. To examine gender differences in orthostatic increases in vascular stiffness during the head-up tilt test (HUTT), standardized by hydrostatic column height. <b>Materials and Methods:</b> A total of 133 healthy adults aged 18-20 years (93 females and 40 males) were evaluated. Blood pressure and pulse wave velocity at the brachial-ankle artery site (baPWV) were measured using an ABI system 100 PWV multichannel sphygmomanometer. Orthostatic changes in arterial stiffness were assessed during a head-up tilt test (HUTT) using the Luanda protocol, which standardizes hydrostatic column height. The functional reserve coefficient (FRC) of orthostatic circulatory regulation was introduced as a measure of adaptive capacity: FRC = ΔbaPWV/baPWVb. This coefficient accounts for both structural (baPWVb) and functional (ΔbaPWV = baPWVt - baPWVb) components influencing cardiovascular system adaptation, which exhibit multidirectional changes with age. <b>Results:</b> Baseline baPWV (baPWVb) values in the horizontal position showed no significant differences between genders and were within normal age ranges. However, baPWV values in the upright HUTT position (baPWVt) were significantly higher in men (<i>p</i> = 0.0007). Dynamic biomarkers of vascular reserve, including ΔbaPWV and FRC, were also significantly elevated in men (<i>p</i> = 0.0009 and <i>p</i> = 0.0064, respectively). <b>Conclusions:</b> While baseline baPWVb values were comparable between genders, dynamic biomarkers of vascular reserve, such as ΔbaPWV and FRC, were significantly higher in men. Prospective studies are needed to establish optimal reference values for these dynamic biomarkers, enabling the assessment of individual trends in vascular aging and evaluating the effects of treatment, lifestyle modifications, and other preventive measures on vascular health.