Link Between Arterial Stiffness and Cognitive Function Persists in Diverse Groups

Arterial stiffness has been associated with cognitive performance, and the gold standard for measuring vascular stiffness is pulse-wave velocity using arterial tonometry. In a study presented at the American Academy of Neurology annual meeting, researchers looked to determine whether estimated pulse-wave velocity is associated with cognition in a racially and ethnically diverse sample of older adults.

In this exclusive MedPage Today video, investigator Botagoz Aimagambetova, MD, of the McKnight Brain Institute in Miami, offers the results and conclusions of the study.

Following is a transcript of her remarks:

Hi everyone. My name is Botagoz Aimagambetova. I’m a cardiologist and currently a student of Master of Science at the University of Miami. I want to talk about an association between arterial stiffness and cognitive function. So this presentation is about the association between estimated pulse-wave velocity and cognitive function in the Northern Manhattan Study.

So the goal of our study was to determine this association among racially and ethnically diverse older adults. So NOMAS or Northern Manhattan Study is an ongoing prospective registry of stroke incidents: 1,290 participants were included in our study. All of them underwent MRI, all of them had neuropsychological assessments, and all of them had calculated estimated pulse-wave velocity. So the average age of our population was 64 years, 60% were women, and 46% of our population had completed high school level.

The most important of our study is several facts. First is race/ethnic distribution. So our population was represented by 66% of Hispanics, 17% of Blacks, 15% of whites, and 2% of other. Currently, only two studies are available, and one of them was done on a Korean population and another one was done on white and Blacks. So our study considers Hispanics and is closer to a real distribution among Americans.

This formula was generated first by reference values in 2010, and later in 2016 it was modified by collaborators of Sara Greve for subjects with cardiovascular risk factors and without. Definitely in our study we used the formula, which was modified for cardiovascular risk factors.

So another important fact of our study is that the Northern Manhattan Study used a very wide list of neurocognitive tests. So global cognition was grouped into four cognitive domains as episodic memory, executive function, process speed, and semantic memory.

And every cognitive domain underwent a long list of multiple cognitive tests, which is very important because only few studies has a long list of these kind of assessments. Brain damage marker were assessed via MRI.

Cognitive performance scores were regressed on estimated pulse-wave velocity in three models: so model 1 was adjusted for demographics; model 2 was adjusted for demographics and vascular risk factors such as high blood pressure, high cholesterol, diabetes, and so on; and model 3 included the previous two models — demographics, vascular risk factors — as well as brain damage markers, such as white matter hyperintensity, silent brain infarct, and cardiovascular spaces.

In this table, we can see the vascular markers and brain damage markers. Also in our study, we consider the number of APOE ε4 allele carriers, which is important that every four individuals was an APOE ε4 allele carrier, which explains why they have atherosclerosis.

And the most important fact from this study is this line — estimated pulse-wave velocity. So the recommended threshold was at the level of 10 units and our study shows increased level. Our population was aging, but cognitively intact. So this number at this point already shows us that aging individuals, which have hypertension and increased cholesterol has stiff vasculature, and that’s why the vascular burden may explain why this population will have any kind of cognitive decline.

So the results of our study suggest that estimated pulse-wave velocity plays an important role in global cognitive function, in processing speed, and memory. The association between estimated pulse-wave velocity and cognitive performance persists among all age and race/ethnic groups, which is also very important. And last but not least is that fact that estimated pulse-wave velocity can serve as a important clinical marker of cognitive function in aging individuals before symptoms appears.