July 7, 2009
Could how fast you button your shirt be an early indicator of Alzheimer's disease?
It may. Those are the intriguing findings from researchers who developed a risk tool for Alzheimer's disease. The findings appeared in Neurology, the medical journal of the American Academy of Neurology.
Various tools have been developed by researchers over the years to assess the likelihood of somebody developing heart disease, say, or breast cancer, or diabetes. However, no such tool currently exists for Alzheimer's. Now, researchers have developed a preliminary tool that may help predict whether someone age 65 or older is at low, moderate or high risk of developing dementia over the next six years.
"This new risk index could be very important both for research and for people at risk of developing dementia and their families," said study author Deborah E. Barnes, Ph.D., M.P.H., of the University of California, San Francisco, San Francisco Veterans Affairs Medical Center. "It could be used to identify people at high risk for dementia for studies on new drugs or prevention methods."
In addition, Dr. Barnes added, "The tool could also identify people who have no signs of dementia but should be monitored closely, allowing them to begin treatment as soon as possible, and potentially helping them maintain their thinking and memory skills and quality of life longer." Such a tool could also be useful for providing predictive information to concerned patients and their family members.
The risk index was developed from findings from the ongoing Cardiovascular Health Cognition Study. People who scored eight or more points on the scale, which ranged up to 15, were at high risk of developing dementia in the next six years, the study found.
Several of the items on the scale are well-known risk factors for Alzheimer's disease. These include being an older age, having low scores on tests of thinking skills, and having a gene that has been linked to the disease.
Other factors predicting dementia risk were more surprising. People who are underweight, do not drink alcohol, have had coronary bypass surgery, or are slow at performing physical tasks like buttoning a shirt are more likely to develop dementia than people who do not have these risk factors, the researchers found.
To develop the index, researchers in the Cardiovascular Health Study examined 3,375 people whose average age was 76. None had signs or symptoms of Alzheimer's at the start of the study, and they were followed for six years. During that time, 480 of the people, or 14 percent, developed Alzheimer's or another form of dementia. The researchers then determined which factors best predicted who would develop dementia and created the point index.
A total of 56 percent of those with high scores on the index developed dementia, compared to 23 percent of those with moderate scores and 4 percent of those with low scores. Overall, the index correctly classified 88 percent of the participants.
Dr. Barnes said the risk index needs to be validated with other studies. She and her colleagues are determining whether a shorter, more simplified index could be as accurate as this index.
The study was supported by the National Institutes of Health, the National Heart, Lung, and Blood Institute, the National Institute on Aging, and the National Institute of Neurological Disorders and Stroke.
D. E. Barnes, Ph.D., M.P.H.; K. E. Covinsky, M.D., M.P.H.; R. A. Whitmer, Ph.D.; et al: "Predicting Risk of Dementia in Older Adults: The Late-Life Dementia Risk Index." Neurology, May 13, 2009.