MONDAY, May 22, 2006 (HealthDay News) -- Poor physical function may be a warning sign of increased risk of Alzheimer's disease and other dementias, a new study suggests.
"Our point is that you don't want to separate the mind from the rest of the body," said study co-author Dr. Eric Larson, director of the Group Health Center for Health Studies, in Seattle. "The two are inextricably linked in older people," he added.
"Even the mildest degree of physical disability is going to predict a heightened risk for Alzheimer's," added Dr. Gary Kennedy, a geriatric psychiatrist and chairman of the Geriatric Mental Health Foundation at Montefiore Medical Center in New York City. "This adds a little to diagnostic precision when we're looking for who's at risk and who's not, so we can provide interventions that prevent," he said.
While some previous studies have found a relationship between physical function and cognitive ability, they haven't explored how physical performance is linked to the development of dementia or cognitive impairment, which is often a precursor to dementia.
For the new study, which appears in the May 22 issue of the Archives of Internal Medicine, investigators looked at 2,288 men and women aged 65 and older who did not have dementia when the study began.
Cognitive abilities were assessed and ranked at the beginning of the study. Physical function was assessed, according to several established tests: a timed, 10-foot walk; a "chair-stand test" that timed participants as they stood from a seated position five times; a standing balance assessment; and a measurement of grip strength in the dominant hand.
Assessments were updated every other year for an average of six years.
At the beginning of the study, individuals with lower physical-performance scores also had lower cognitive scores.
As the study progressed, people with higher physical-performance scores were three times less likely to develop dementia than those with lower scores.
The first physical indicators of a risk for dementia in people without cognitive impairment seemed to be problems with walking and balance. And among people with apparent mild cognitive impairment, a weak handgrip suggested they would progress to dementia, the study found.
In other words, balance and walking problems may occur during an earlier stage while a weak handgrip may occur during a later stage.
The good news is that stepping up physical activity levels may also have a stalling effect on dementia.
The same research team had earlier found that seniors who engage in some form of minimal exercise at least three days a week can cut their risk of developing Alzheimer's and other forms of dementia by as much as 30 percent to 40 percent. The message from that study, Larson said, was "use it even after you start to lose it."
And that message may be equally applicable here.
"If you notice physical function declining, it's arguably a good idea to rehab yourself or have a strong physical exercise program early on," Larson said. "I'm very excited about this," he said. "Something as simple as regular walking may lessen the rate of dementia."
Kennedy added: "If you think the person has very subtle decrements in motor performance, it might be worthwhile to get them up and out and more physically active. It's never too late to start exercise."
For more on Alzheimer's, visit the National Institute on Aging.