1st Signs of Dementia May Be Physical
Mental Declines Come Later, Study Suggests
May 22, 2006 - The first signs of Alzheimer’s disease and other forms of dementiadementia among older people may be physical rather than mental, new research suggests.
The findings are a strong indicator that physical and mental performance among the elderly are interconnected, researcher Eric B. Larson, MD, tells WebMD.
“If we expect the earliest sign of dementia to be subtle changes in cognition, we are probably going to be wrong,” he says.
The study by Larson and colleagues at the University of Washington and the VA Puget Sound Health Care System included 2,288 older people followed for six years.
All the participants were members of a Seattle-based managed care cooperative, and all were aged 65 or older at study entry. None was diagnosed with dementia or Alzheimer’s disease at enrollment in the trial, based on standardized cognitive testing, which was repeated every two years.
Physical function testing was also conducted -- evaluating for walking, standing balance, hand grip, and the time needed to stand from being seated in a chair repeated five times.
At the beginning of the study, people with lower baseline physical-performance scores also had lower baseline cognitive test scores. During the six years of follow-up, 319 study participants developed dementia, with 221 of these having a diagnosis of Alzheimer’s disease.
Each 1-point decline in physical-performance score was associated with an increased risk for developing dementia -- with 16 points representing the best physical function and 0 representing the worst. People who scored higher than 10 were far less likely to develop dementia than those with scores of 10 or lower.
Gait slowing and poor balance were more common in people later diagnosed with Alzheimer’s or some other dementia. Poor handgrip seemed to be associated with later dementia in people who already showed early signs of mild cognitive decline.
Can Exercise Delay Alzheimer’s?
The new study, supported by a grant from the National Institute on Aging, is published in the May 22 issue of the Archives of Internal Medicine. In another study published earlier this year, Larson and colleagues concluded that regular exercise may reduce the risk of Alzheimer’s among older adults.
Older people in the earlier study who reported exercising three times a week or more developed Alzheimer’s a third less often during the six-year-old study than people who exercised less.
Larson says an older person who does not exercise and is declining physically should be encouraged to become more physically active.
“Many people just sit down and accept the inevitable, and if you accept the inevitable you will get it,” he says.
Dallas Anderson, PhD, of the National Institute on Aging, agrees that regular exercise is important for the elderly for a host of reasons. But he adds that it is not yet clear if delaying the onset of Alzheimer’s is one of them.