While far less studied than arteries that carry oxygen-rich blood away from the heart, veins play a critical role in the circulatory system. These vessels channel blood back to the heart, and their flexibility is a major factor affecting how much blood the heart gets.
In a two-year study, William Farquhar and colleagues at the University of Delaware College of Health Sciences and Christiana Care Health System compared vein elasticity in healthy older and younger people. "As we expected, we did find that the older subjects had less elastic veins compared with younger subjects. It's consistent with the loss of artery elasticity with age. Veins, like arteries, stiffen with as we get older."
Researchers studied the proteins that make up the vein walls and concluded that structural changes within the vein wall are responsible for that age-related loss of elasticity.
Farquhar says he is not sure what causes that change. It may be related to an increase in the protein that makes the vein wall thicker. He says other factors besides age may affect the rate at which veins stiffen. "Exercise may have an influence. Disease processes may have an influence, as it seems to accelerate in individuals with hypertension or diabetes."
University of Delaware researchers next plan to study vein elasticity in people with hypertension, a disease that affects 65 million Americans.
The current study appears in the Journal of Applied Physiology.