Introduction and purpose. Endothelial cells are subjected to biomechanical stress produced by the bloodstream and tunica media of the vessel. Vascular stiffness and endothelial shear stress have cooperative effects on the endothelial structure and function. However, the relationship of shear stress and arterial stiffness is still poorly understood. The purpose of the study was to assess the relationship of endothelial shear rate and both local and regional vascular stiffness in patients at different stages of the development of atherosclerosis. Methods. The study included 60 patients, 33 men and 27 women. The average age of patients was 54.8±11.7 years. Regional arterial stiffness was assessed by measurement of the pulse wave velocity in the arteries of elastic and muscular types. Local stiffness of the carotid arteries was characterized by Peterson elastic modulus, Young's modulus, stiffness index β, the deformation of the common carotid artery. Endothelial shear rate was measured at the site of the common carotid artery. Results. Average values of carotid endothelial shear rate were equal to 433±127 s-1. Reduced endothelial shear rate in the carotid arteries was associated with an increased Peterson modulus (r = -0.289; p = 0.025) and the stiffness index β (r = -0.280; p = 0.037), and moreover - with decreasing vascular distensibility (r = 0.288; p = 0.026) and deformation (r = 0.296; p = 0.024). Assessment of the relationship between endothelial shear rate and regional vascular stiffness showed weak statistically significant negative correlation of shear rate and PWVcf (r = -0.367; p = 0.014). Conclusion. In study subjects endothelial shear rate reduction in the area of the common carotid artery was associated with an increased Peterson modulus, stiffness index β, decreasing deformation of carotid arteries and increase in aortic stiffness.
Ultrasonographic strain imaging is superior to conventional non-invasive measures of vascular stiffness in the detection of age-dependent differences in the mechanical properties of the common carotid artery