The UCLA team measured the volume of cerebral arteries using a technique called arterial spin labeling. They measured once at the systolic phase of the cardiac cycle, when the heart is pumping blood into the brain, and again at the diastolic phase, when the heart is relaxing.
The stiffer the arteries they tested, the smaller the change in the arterial blood volume between the two cardiac phases, because stiff arteries are less able to change shape or comply with blood pressure changes, said Danny Wang, the study’s senior author and an associate professor of neurology at UCLA.
“Vascular compliance is a useful marker for a number of cardiovascular diseases, such as hypertension and diabetes,” said Wang, who is also a researcher in UCLA’s Ahmanson-Lovelace Brain Mapping Center.
The researchers found that elderly people have much stiffer arteries than do young people. They also found that increased arterial stiffness is associated with reduced cerebral blood flow, suggesting stiff arteries impair the blood supply to the brain.
- Kim Irwin