“…In vitro studies have demonstrated that unidirectional high shear stress induces the expression of antiatherogenic genes (i.e., endothelial nitric oxide synthase and superoxide dismutase) and inhibits the expression of atherogenic genes (i.e., vascular cell adhesion molecule, intercellular adhesion molecule, and endothelin-1), whereas retrograde shear and/or low mean shear promote a proatherogenic phenotype [24]. A previous follow-up study reported that decreases in mean carotid artery shear stress correlated with increases in carotid artery IMT [25]. In peripheral conduit arteries, acute and chronic increases in antegrade shear have beneficial effects on arterial function [12,13,26], whereas acute and chronic increases in retrograde shear are associated with endothelial dysfunction [14,15,27].…”