High Blood Pressure Does Not Accelerate Age-Related Cognitive Decline
DURHAM, N.C. - Duke University Medical Center researchers have found that contrary to the classical model of aging, increased blood pressure does not accelerate the age-related decline in performing certain mental tasks.
Furthermore, the researchers reported, middle-aged subjects with high blood pressure showed more of a slowing in cognitive performance tests than did older adults with high blood pressure.
According to the researchers, past studies have been epidemiological in nature and have hinted that hypertensive patients perform worse than individuals with normal blood pressure on cognition tests, as measured by the speed of mental processing, attention, and memory tasks. However, unlike the new Duke study, which was performed in a laboratory setting, previous studies have been unable to tease out relationships between elevated blood pressures and age on specific cognitive tasks.
The results of the Duke experiments were published today (Sept. 29, 2003) in the September issue of the journal Aging, Neuropsychology and Cognition. The study was supported by the National Institutes of Health.
"While the changes in cognitive performance associated with elevated blood pressure seen in our experiments were statistically significant, they are unlikely to interfere with mental functioning during everyday life," said Duke's David Madden, Ph.D., cognitive psychologist and researcher in aging. "However, the changes we recorded in the laboratory may represent a situation that could become clinically significant when other diseases, especially those that are cardiovascular in nature, are included.
"The significance of these cognitive effects will become clearer as additional evidence is obtained regarding the changes in brain structure and function that typically accompany chronically elevated blood pressure," Madden said.
Unlike the previous studies, where patients often had other diseases and might have been on medications, the Duke team focused exclusively on participants who had high blood pressure, but who were not taking any medications. None of the participants had detectable cardiovascular disease.
"We know that in general, hypertension increases with age," Madden said. "Our goal was to determine if there was any effect of elevated blood pressure on the natural course of healthy aging."
For their experiments, the Duke team recruited 96 adult volunteers