ELN and endothelial dysfunction: At the level of the arterial wall, aging is associated with inflammation and oxidative stress leading to the reduced bioavailability of nitric oxide (NO), increased production of elastase and collagenase, hyperplasia, and cross-differentiation of vascular smooth muscle cells that result in functional (i.e., endothelial dysfunction) and structural changes in the arterial wall (i.e., disruption of normal elastin and collagen and substitution with altered proteins) and arterial stiffening [22].