TUESDAY, Oct. 5, 2004 (HealthDayNews) -- For years, experts have known that high blood pressure is related to poor cognitive performance in older adults and can lead to adverse changes in the brain.
Now, researchers report that young adults with high blood pressure are just as susceptible to decreased mental function as are older people are.
The study appears in the November issue of Hypertension.
Younger people aged 18 to 46, as well as those above 47, had a decline in cognitive function as their blood pressures rose.
"Although they perform better than older people in general, young people showed a decline over time in relation to rising blood pressure," said Merrill F. Elias, study co-author with his wife, Penelope K. Elias, both psychologists at the University of Maine, Orono.
"The message is simply, we can't avoid treating younger people because one of the side benefits of treating is to prevent this kind of cognitive decline," he said.
High blood pressure boosts the risk of stroke and heart attack, and it's been tied to dementia as well. While it's known that high blood pressure causes vascular dementia, the second most common type of dementia after Alzheimer's disease, experts aren't certain of the relationship between blood pressure and Alzheimer's itself.
In the study, the researchers evaluated 529 participants in the Maine-Syracuse Longitudinal Study of Hypertension, in which the first patients were enrolled in 1976. Blood pressure readings were evaluated at entry to the study and again during up to four follow-up visits.
During the first measure and at each follow-up, participants took a test of cognitive function. The subjects were divided into two age groups, those from 18 to 46 and those from 47 to 83.
Regardless of age, higher blood pressures over time correlated with a decrease in the ability to react and respond to novel information, what researchers call "visualization/fluid abilities."
An example of this, Elias said, is you might be presented with complex visual material that you have not seen before and be asked to organized it in a certain way.
"Over 20 years, those who were at stage one hypertension at baseline [defined for this study as pressures of 140 to 159 over 90 to 99] had a 8.12 percent decline in cognitive tests compared to those who were normal [defined for the study as less than 120 over 80] at baseline." Pressures of less than 120 systolic (measured as the heart beats) over less than 80 diastolic (as the heart relaxes between beats) are now recommended.
The study confirms what has been suspected, said Dr. Daniel Jones, dean of the School of Medicine at the University of Mississippi Medical Center and an American Heart Association spokesman. "This confirms that the subtle damage from high blood pressure that may lead to dementia begins at an early age," he said. "This is the first study that has been reported in a young age group."
"It's not so much that it's a new idea, but that it's important confirmation," he continued, adding that young people need to be concerned about their blood pressure status. "This is clear evidence that the damage to the blood vessels slowly evolves over time, and that management of high blood pressure in young adults is not just beneficial for older age people but has real-time benefits in the preservation of cognitive function."
To learn more about high blood pressure, visit the National Heart, Lung, and Blood Institute.