Cardiovascular disease is a major health risk throughout the industrialized world. Atherosclerosis, the most prevalent of cardiovascular diseases, is the principal cause of heart attack, stroke, and gangrene of the extremities. It is also the principal cause of death in the United States.

This invention portrays a method for diagnosing decreased vascular function, detecting increased cardiovascular risk and diagnosing atherosclerosis. An embodiment includes assaying the number of endothelial progenitor cells and treating a subject with decreased vascular function by administering a therapeutically effective amount of endothelial progenitor cells.