The role of the endothelial glycocalyx in advanced age and cardiovascular disease

•The endothelial glycocalyx is a gel-like structure that lines the endothelium.•In advanced age and cardiovascular disease (CVD), the glycocalyx is deteriorated.•An intact glycocalyx is critical to a properly functioning endothelium.•Glycocalyx deterioration may initiate age-related CVD pathology. The endothelial glycocalyx is a gel-like structure that is bound to the luminal surface of the vascular endothelium. At the interface between flowing blood and endothelial cells, the glycocalyx has several functions that are critical for the maintenance of a healthy vasculature, particularly in regard to the vascular endothelium. Within the vasculature, the glycocalyx modulates vascular resistance to maintain blood flow homogeneity in the microcirculation, mechanotransduces fluid shear stress to the endothelium, and buffers endothelial cells from plasma oxidants, cytokines, and circulating immune cells. In advanced age and cardiovascular disease (CVD), the glycocalyx is deteriorated. Moreover, glycocalyx deterioration may precede traditional measurements of age-related vascular dysfunction, such as impaired endothelium-dependent dilation and large artery stiffness, suggesting that a deteriorated glycocalyx could initiate age-related CVD pathology.