Effects Of Body Position On Carotid-femoral Pulse Wave Velocity

Pulse wave velocity (PWV) serves as index of arterial stiffness and is typically measured with individuals in a supine position. The increased arterial stiffness assessed with cfPWV could be a risk of total cardiovascular events and all-cause mortality. A previous study reported that cfPWV elevates during the upright posture compared with the supine position. If a seated position acutely increases arterial stiffness, it would potentially heighten the risk of cardiovascular disease, especially during an upright seated position. PURPOSE: The purpose of this study was to examine whether arterial stiffness progresses in the sitting position by comparing the supine and sitting positions. METHODS: Twenty young healthy subjects (Female; n = 6) underwent the measurement of arterial stiffness at the supine and seated positions to validate the credibility of alteration in cfPWV especially. At supine and seated position, arterial stiffness was assessed by cfPWV using applanation tonometry and carotid artery compliance and β-stiffness index using applanation tonometry and ultrasound. RESULTS: cfPWV values significantly increased in seated compared to supine (supine vs seated; 5.41 ± 0.62 cm/s vs 6.19 ± 0.77 cm/s, P < 0.001). However, there were no significant differences in carotid artery compliance and β-stiffness index between the two positions (P = 0.380 and P = 0.209, respectively). CONCLUSIONS: In contrast to the result of cfPWV, this finding indicates that an acute change in body position did not alter arterial stiffness at the carotid artery. The findings of the present study suggest that changes in body position do not lead to an acute alteration in arterial stiffness at the carotid artery. Despite this, the mechanism behind the variation in cfPWV during postural changes remains elusive. One possible explanation might involve differences in hydrostatic pressure, as the assessment of arterial stiffness through blood flow velocity could be affected. However, additional research is required to precisely identify this discrepancy in measurements.