Physical activity may reduce dementia in oldest seniors
A regular exercise program has many benefits. A new study has found that regular physical exercise may ward off dementia in oldest seniors. Researchers affiliated with the Department of Neurology, University of California, Irvine (UCI) published their findings online on October 22 in the journal Archives of Neurology.
The researchers noted that a study on the oldest seniors, the 90+ Study is a population-based, longitudinal, epidemiologic study of aging and dementia was conducted at UCI from January 1, 2003, through November 30, 2009. The researchers selected 629 participants from The 90+ Study for review. The average age was 94 years, and most (72.5%) were women. The main outcome measure was all-cause dementia, based on Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria. The independent variables were physical performance measures, including 4 meter walk (4.1 yards), 5 chair stands, standing balance, and grip strength; each variable was scored from 0 to 4 (0: unable to perform; 4: best performance).
The odds of dementia in relation to the physical performance measures were estimated by logistic regression after adjustment for age and sex. Logistic regression measures the relationship between a categorical dependent variable (age in this case) and one or more independent variables (In this case, a 4 meter walk, 5 chair stands, standing balance, and grip strength. The dependent variable is converted to a probability scores.
The researchers found that poor physical performance in all measures was significantly associated with increased odds of dementia. Odds ratios for every unit decrease in physical performance score were 2.1 for the 4 meter walk, 2.1 for chair stands, 1.9 for standing balance, and 1.7 for grip strength. The study found a strong relationship between poor physical performance and dementia; the most notable effect was the 4-meter walk test. Those who were unable to walk (score 0) were almost 30 times more likely to have dementia than participants with the fastest walking time (score 4). Even a minimal decrease in walking speed ( about 1.5 seconds, from score 4 to score 3) resulted in a 4 times greater odds of dementia.
The next highest odds of dementia were associated with poor performance in the 5 chair stands, which required participants to stand from a sitting position with their arms folded across their chest, followed by grip strength in the dominant hand, and standing balance in various positions.
The authors concluded that they found a strong cross-sectional relationship between poor physical performance and dementia in individuals 90 years of age and older. They noted that their findings suggest that dementia is a complex neurodegenerative process that may affect physical performance and cognition. They recommended that additional research should be conducted to determine the temporal relationship between poor physical performance and cognitive dysfunction.
Take home message:
Obviously, as dementia increases, the ability to engage in physical activity decreases. Thus, the more demented seniors performed at a lower level in this study. However, it is likely that in some cases, increased physical activity played a role in decreased dementia. Exercise stimulates the circulation, including blood flow to the brain.
Archives of neurology