Assessing vascular health by measuring arterial stiffness in response to hemodynamic load

Arterial stiffness, a well established cardiovascular risk factor, is accelerated in metabolic conditions such as diabetes and chronic kidney disease. It is typically assessed by measuring pulse transit time along an arterial path in the supine position. We hypothesized that introducing a hydrostatic pressure gradient by changing body position could reveal additional vascular biomechanical properties. This study aimed to quantify the increase in finger-to-toe pulse wave velocity (Δft-PWV) from supine to sitting and identify its determinants across varying cardiovascular risk profiles.

In this cross-sectional study, 248 adults were recruited, and 210 had reliable ft-PWV measurements in both positions. Ft-PWV was determined from pulse transit time between the finger and toe using two photoplethysmographic sensors.

The mean age of participants was 55 ± 19 years; 112 (53%) were male, 104 (50%) had hypertension, 76 (36%) had diabetes, and 75 (36%) were on hemodialysis. Mean SBP and DBPs were 127 ± 17 and 77 ± 12 mmHg (mean ± standard deviation). Ft-PWV increased significantly from 8.5 ± 3.3 m/s (supine) to 14.3 ± 9.1 m/s (sitting; P  < 0.001). In univariable analyses, Δft-PWV was significantly associated with supine ft-PWV ( r  = 0.405, P  < 0.001), age ( r  = 0.337, P  < 0.001), diabetes ( r  = 0.219, P  < 0.001), and cardiovascular disease ( r  = 0.188, P  = 0.006). Sex, dialysis status, weight, height, and mean BP changes were not significantly associated with Δft-PWV. In stepwise multivariable regression, Δft-PWV was independently associated with supine ft-PWV (β = 0.379, P  < 0.001) and diabetes (β = 0.154, P  = 0.016).

Ft-PWV increased significantly from supine to sitting. The magnitude of change was independently associated with supine ft-PWV and diabetes, highlighting biomechanical insights from postural change.