Pittsburgh, PA—When older adults show high risk for developing mental deficiencies, the common assumption is that little or nothing can be done to keep them from developing full-fledged dementia.

A new study in Journal of Alzheimer's Disease argues against that view, however, pointing out that medications can modify risk factors in patients with arterial stiffness.

University of Pittsburgh researchers reveal that arterial stiffness is a good indicator for who is likely to go on to develop dementia, better even than minor signs of brain disease. The good news, they add, is that arterial stiffness can be reduced by antihypertensive drugs, and possibly lifestyle interventions—preventing, or at least delaying, dementia.

“As the large arteries get stiffer, their ability to cushion the pumping of blood from the heart is diminished, and that transmits increased pulsing force to the brain, which contributes to silent brain damage that increases dementia risk,” explained senior author Rachel Mackey, PhD, MPH, assistant professor of epidemiology, University of Pittsburgh Graduate School of Public Health. “Although arterial stiffness is associated with markers of silent, or subclinical, brain damage and cognitive decline, until now, it was not clear that arterial stiffness was associated with the risk of dementia.”

For the study, researchers analyzed the association between arterial stiffness and dementia among 356 older adults with an average age of 78 years . They were part of the Cardiovascular Health Study Cognition Study (CHS-CS), a long-term study to identify dementia risk factors, and the findings are especially significant because CHS-CS participants had almost complete follow-up of cognitive status and outcomes for 15 years.

Aortic stiffness reduces the buffering of pulsatile blood flow, exposing cerebral small arteries to microvascular damage. The condition can be measured using carotid-femoral pulse wave velocity (cfPWV), high levels of which are related to white-matter hyperintensities and brain amyloid deposition, and to cognitive decline.

The study team determined that cfPWV was significantly associated with increased risk of dementia, but systolic blood pressure, mean arterial pressure, and pulse pressure were not. What remained unclear, however, was whether interventions to slow arterial stiffening could reduce the risk of dementia.

“It's very surprising that adjusting for subclinical brain disease markers didn’t reduce the association between arterial stiffness and dementia at all,” points out first author Chendi Cui, MS, a doctoral student at Pitt Public Health. “We expect that arterial stiffness increases the risk of dementia partly by increasing subclinical brain damage. However, in these older adults, arterial stiffness and subclinical brain damage markers appeared to be independently related to dementia risk.”

Researchers consider that promising because, while it probably isn’t currently possible to reverse subclinical brain disease, arterial stiffening can be reduced by antihypertensive medication and perhaps also healthy lifestyle changes such as exercise. In fact, the study indicates that exercise at an average age of 73 years was associated with lower PWV 5 years later.

“What’s exciting to think about is that the strong association of arterial stiffness to dementia in old age suggests that even at age 70 or 80, we might still be able to delay or prevent the onset of dementia,” Mackey emphasized.

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