High Blood Pressure Linked to Disability, Dementia

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"People with stiffening of their arteries show a decline in memory and concentration as they grow older," Waldstein said.

The Maryland researchers collected data on 1,749 people in the Baltimore Longitudinal Study of Aging, which was started by the U.S. National Institute on Aging in 1958.

During the study, participants were screened for increased pulse pressure, which is the difference between the maximum and minimum blood pressures produced during one heartbeat. In addition, their brain function was tested. This was done through tests of verbal and non-verbal memory, working memory, and attention.

In addition, Waldstein's team looked at additional data on 582 people who had their pulse wave velocity measured. Measuring pulse wave velocity is a new method for analyzing pulse pressure. Rising pulse pressure is an indicator of arterial stiffness.

The researchers found that increases in pulse pressure and pulse wave velocity affected memory. However, arterial stiffness wasn't linked to attention, hand-eye coordination, the ability to name objects, and speech fluency.

"Arterial stiffening negatively impacts cognitive performance before people have a stroke or develop dementia," Waldstein noted.

The findings suggest that arterial stiffness may be a potential target for drugs to help preserve mental function, Waldstein said. "Early treatment of cardiovascular risk factors that lead to arterial stiffening may help to preserve brain functioning as people age," she suggested.

One expert isn't sure whether high blood pressure is a cause of disability and dementia, or whether it's a marker associated with these conditions.

"Whether reducing blood pressure reduces disability and dementia isn't really known," said Dr. Harlan M. Krumholz, a professor of medicine at Yale University School of Medicine.

"It's part of a complex syndrome," he said. "Having high blood pressure is associated with having small sub-clinical strokes and heart disease, and there can be other complications from medications that don't interact well with each other."

Krumholz thinks that for any given patient, the reasons for dementia and disability are complex. "But, even as we are trying to sort out what these studies mean, the clear and unequivocal recommendation for people is to get high blood pressure under control," he said.

More information

For more on high blood pressure, visit the American Heart Association.