Stroke Risks Associated with Reduced Mental Functioning
Contact: Nick Houtman at 207-581-3777
ORONO, Maine — Personal health factors that contribute to a higher risk of stroke can also lead to reduced cognitive functioning, according to a study released today by the American Medical Association at a meeting in New York City. A research team led by Merrill “Pete” Elias of the University of Maine and Boston University has found that the more at risk a person is for having a stroke within the next ten years, the lower that person is likely to score on cognitive tests involving abstract reasoning, visual spatial planning, organization and concentration, scanning and tracking.
“Changes in cognitive function can be a very sensitive indicator of changes in the brain,” says Elias. “The bottom line is that people at higher risk for stroke perform less well on cognitive tests. The practical outcome is additional support for prevention of stroke risks in the first place and then early intervention when changes in cognitive function are detected.”
The study is based on data from 2,175 participants of the Framingham Offspring Study (offspring of the Framingham Heart Study participants) who were free from stroke and dementia and had taken a battery of neuropsychological tests at Examination 7 in a series of longitudinal examinations. The subjects ranged in age from 33 to 88 years old, and 54 percent were women.
The report is due to be published online today in Stroke: Journal of the American Heart Association. Co-authors include Lisa M. Sullivan, Ph.D., and Alexa Beiser, Ph.D., of the BU School of Public Health; Ralph B. D’Agostino, Ph.D., and P. K. Elias, Ph.D., of the BU Statistics and Consulting Unit; Rhoda Au, Ph.D., Sudha Seshadri, M.D., and Philip A. Wolf, M.D. of the BU Department of Neurology and Charles DeCarli, M.D. of the University of California-Davis.
The Framingham Heart Studies are supported by the National Heart, Lung, and Blood Institute (NHLBI) and the National Institute on Aging.
“Using the Framingham Stroke Risk Profile, we assessed the probability of each individual experiencing a stroke within ten years, and we found that the higher the probability of stroke, the lower the level of cognitive function,” says Elias.
None of the subjects in the study had ever experienced a stroke. In addition, the data were controlled for other factors that are associated with lower cognitive function such as age, education, high blood pressure and a diagnosis of dementia. The Framingham and other studies have established that factors such as smoking, high systolic blood pressure, diabetes, cardio-vascular disease, atrial fibrillation, and left ventricular hypertrophy increase the chances of having a stroke within ten years. These risk factors are included as weighted predictors of stroke in the Framingham Stroke Risk Profile.
“People don’t just wake up one morning and find that they are demented,” Elias adds. “They progress over time. It is important to note that there are treatments that can improve cognitive function, including new drugs that are in development as well as diet and exercise.”
The study presents a snapshot in time of stroke risk factors and cognitive function for participants in the study. It does not follow individuals over time to determine how mental functioning might change relative to such risk factors. Since 1974, Elias has led the Maine-Syracuse Studies of Hypertension and Cognitive Functioning that are designed to assess changes in mental functioning over time. Elias has been a Framingham Heart Study Investigator since 1990.