The only way to detect that arteries are vulnerable to atherosclerosis is to assess endothelial function. This is a test of the endothelial cells that line all the arteries in the body. The endothelium is the single layer of cells that line various organs and cavities, especially the heart, blood and lymphatic vessels. These cells act as a shield, preventing plaque from forming inside the artery wall, and produce substances that stop blood clots from developing in the vessel.
Healthy endothelial cells release nitric oxide (NO), which is responsible for most of the protective functions of these cells in the artery.
In an at-risk individual, the endothelial cells do not produce enough NO, or the NO produced is deactivated by chemicals in the bloodstream before it can prevent deposits from forming in the arterial wall.
Dysfunction is defined as the failure of the endothelial cells to respond normally to stimulation, which can leave the artery walls unprotected and plaque can begin to accumulate as a result. This foreshadows the beginning of atherosclerosis.
Monitoring endothelial function is therefore critical to assess present and future risk of vascular disease.
To review some of the science regarding endothelial function, please review these Scientific Studies.