Loss of elasticity in blood vessels occurs for a number of reasons, including the rising level of persistent cross-links that glue together important structural proteins, effects of chronic inflammation on mechanisms needed for blood vessel elasticity, and so forth. This form of structural failure has material consequences, raising the risk of life-threatening events such as stroke.
Exercise has been shown to slow the progression of blood vessel stiffening, and here a new technique for assessing blood vessel stiffness in the brain adds more data in support of that view. More importantly, this sort of technology will be very useful as a means of rapidly assessing the effectiveness of near future rejuvenation treatments, such as means to break glucosepane cross-links presently funded by the SENS Research Foundation:
[Researchers] have developed a new technique that can noninvasively image the pulse pressure and elasticity of the arteries of the brain, revealing correlations between arterial health and aging. The [researchers] routinely record optical imaging data by shining near-infrared light into the brain to measure neural activity. Their idea to measure pulse pressure through optical imaging came from observing in previous studies that the arterial pulse produced strong signals in the optical data, which they normally do not use to study brain function. Realizing the value in this overlooked data, they launched a new study that focused on data from 53 participants aged 55-87 years.
"When we image the brain using our optical methods, we usually remove the pulse as an artifact - we take it out in order to get to other signals from the brain. But we are interested in aging and how the brain changes with other bodily systems, like the cardiovascular system. When thinking about this, we realized it would be useful to measure the cerebrovascular system as we worry about cognition and brain physiology."
The initial results using this new technique find that arterial stiffness is directly correlated with cardiorespiratory fitness: the more fit people are, the more elastic their arteries. Because arterial stiffening is a cause of reduced brain blood flow, stiff arteries can lead to a faster rate of cognitive decline and an increased chance of stroke, especially in older adults. "Noninvasive optical methods can provide estimates of arterial elasticity and brain pulse pressure in different regions of the brain, which can give us clues about the how different regions of the brain contribute to our overall health. For example, if we found that a particular artery was stiff and causing decreased blood flow to and loss of brain cells in a specific area, we might find that the damage to this area is also associated with an increased likelihood of certain psychological and cognitive issues."