Plaque formation in your arteries is called atherosclerosis. The condition can potentially lead to serious heart problems.
For years, it has been known that exercise and age affect the formation of plaques through a process known as atherosclerosis. However, it remains elusive how the geometrical features of the arteries affect plaque formation, although a dilated region in the inner carotid branch, the sinus, appears to be a vulnerable site.
In a new study, engineers in China used fluid dynamics simulations to study the effect of exercise at various ages on plaque formation. They considered two arterial geometries, one with a bulging outer artery and the other without.
They then modeled the effect of exercise and age on blood flow through the two model arteries.
Two main arteries carrying blood to the head and neck, known as the carotid arteries, branch off from a single large artery at a position near the thyroid gland. One branch, the internal carotid artery, or ICA, carries blood inside the cranium to the brain. In contrast, the external carotid artery remains outside the cranium and brings blood to the neck, face, and scalp.
ICA bulges outward just above the bifurcation, forming a sinus sensitive to blood pressure changes and helps regulate blood flow and heart rate.
Author Xiaolei Yang said, “Our work investigated the patterns of disturbed blood flow in two different model carotids, one with high-risk geometrical factors and the other without.”
“High-risk factors include high flare and low proximal curvature in the sinus. Flare is defined as the ratio of the maximum cross-section in the sinus bulb to its minimal value. At the same time, proximal curvature measures how much the artery curves above the bifurcation point.”
Scientists modeled exercise by using digitized blood flow measurements from individuals in three different age groups: 32-34, 54-55, and 62-63.
Yang said, “Overall, the effects of exercise are different for different people. Particularly, we show that exercising decreases the reversed flow volume for the 62-63 age group with the low-risk carotid, which is probably related to the decrease of systolic time interval.”
“This suggests that evaluating the effect of exercise on atherosclerosis requires consideration of patient-specific geometries and ages.”
“For the current findings to become helpful, the analysis should be coupled to physiological and chemical processes occurring at the cellular level.”
- Xinyi He et al. Effects of exercise on flow characteristics in human carotids. DOI: 10.1063/5.0078061