A common and early event in cardiovascular disease (CVD) happens when damage occurs to the vascular endothelium, the thin layer of cells that lines blood vessels. This damage impairs the function of the endothelium, a condition called endothelial dysfunction. Endothelial dysfunction can be caused by several conditions, including diabetes or metabolic syndrome, hypertension, smoking, and physical inactivity . The healthy endothelium not only arbitrates endothelium-dependent vasodilation, but also actively suppresses thrombosis, vascular inflammation, and hypertrophy.