Physical Limitations in the Oldest Old Increase Odds of Dementia

Just published Online First by Archives of Neurology, a study led by Szofia Bullain, M.D., a Fellow in Geriatric Neurology at UCI MIND and a Clinical Instructor in the Department of Neurology, has shown that difficulty performing activities like walking at age 90 and older greatly increases the odds of having dementia.

Dr. Szofia Bullain, Lead Author

Using a cross-sectional design, Bullain and her colleagues found that the oldest old who performed poorly on measures of walking, rising from a chair, standing balance and grip strength were more likely to have dementia than their more able peers.  Odds of developing dementia increased for every unit decrease in physical performance score.  Participants were over twice as likely to have dementia as their performance declined on the four-meter walk (OR = 2.1) and chair stands (OR = 2.1).  Only slightly less so, declining performance on standing balance (OR = 1.9) and grip strength (OR = 1.7) also increased the odds of having dementia.

Among all physical performance measures, walking had the greatest effect on the odds of dementia. Participants who could no longer walk were nearly 30 times more likely to have dementia than those with the fastest walking time.  Minimal slowing itself increased odds of having dementia fourfold.

Consistent with prior research showing a relationship between physical decline and poor cognitive functioning among the younger old, this study points to the possibility that subtle changes in gait and other physical abilities may serve as early markers of cognitive decline.  Additionally, this study highlights the importance of maintaining walking ability into old age to protect against cognitive decline.  Interestingly, one of the possible explanations the authors offer for their findings is that physical decline may lead to physical inactivity, which in turn, precipitates cognitive impairment.  As Dr. Bullain and her co-authors noted, establishing a link between poor physical performance and dementia “may serve as a major stepping stone to further investigate whether poor physical performance is in the causal pathway and a potentially modifiable risk factor for late-age dementia.”

A unique segment of the aging population, the oldest old are the focus of The 90+ Study on aging and dementia being conducted at UCI under the leadership of Dr. Claudia Kawas, Professor in the Departments of Neurology, and Neurobiology and Behavior at UCI.  Participants in the current study included 629 participants of The 90+Study.  The average age of participants was 94 and nearly three-quarters (72.5%) were women.

Dr. Bullain received her M.D. at Semmelweis University, College of Medicine, in Budapest, Hungary.  She completed her post-doctoral research fellowship at Massachusetts General Hospital, followed by an internship in the Department of Internal Medicine at the State University of New York in Buffalo, where she also started her neurology residency.  She came to UCI in 2009, where she completed her neurology residency and is now a fellow in geriatric neurology.

To read the full article, go to the Archives of Neurology, where it was published online on October 22, 2012. doi:10.1001/jamaneurol.2013.583.