Monitoring improvements in memory and walking speed over time can help identify those most at risk of dementia, according to the authors of a new study.
Dementia is related primarily to advancing age. So the burden of dementia is set to increase as the average age of humans on planet Earth steadily rises.
There is currently no cure; however, better outcomes are associated with starting treatment early. For this reason, researchers are focused on finding ways to predict who will most likely develop dementia.
Also, some factors increase dementia risk including hypertension and sedentary behaviour. Knowing through groups tend to develop dementia is helping scientists and clinicians to recognize and treat additional risk factors.
Dual declines and dementia
One of the earliest dementia symptoms is memory loss; however, with age, many people experience cognitive decline, and that doesn’t necessarily progress to dementia.
As a result, memory loss alone is not a reliable way to predict the risk of dementia.
Several studies have concluded that risk of dementia may also be predicted by slower walking speed, or slow gait. Overall, however, the effect size seems to be quite small and gait speed alone is no useful diagnostic tool.
Another study concluded that the individuals most at risk of developing dementia were those whose memory and gait rate decreased together. But since this study included a relatively small group of individuals, all of whom had been admitted to geriatric clinics, it is not clear if the results are applicable to the general population.
With these findings in mind, a group of researchers set out to understand whether decreasing memory and walking speed, taken together, could be linked to increased risk of dementia.
If their theory was correct, this so-called dual decline could become a useful way to predict those at the greatest possible risk.
The researchers have published their findings in the journal Geriatrics.
A new analysis
The researchers have combined data from six large-scale studies for their investigation, including the Mayo Clinic Study of Aging and The Swedish National Study on Aging and Care in the Kungsholmen Population Study.
The guests were all over 60. Memory checks were done, and their walking speeds were evaluated.
The scientists at the start of the study ruled out anyone with pre-existing cognitive impairment or dementia. We also excluded anyone with a particularly slow gait-slower than 0.6 meters per second, or about 2 feet. Notwithstanding the exclusions there were 8,699 people.
The authors compared participants with double decline with those whose walking speeds and memory remained constant, whom they referred to as “usual agers.” Throughout the six studies, the authors found that individuals who experienced decline in memory had a 2.2 to 4.6 times greater risk of developing dementia than usual agers.
The risk of dementia increased from 2.1 to 3.6 times among those who had only decreased gait speed and this effect was only statistically significant in three of the six studies.
The findings were more clearly defined when the scientists considered people who had both walking speed and reduced memory. Investigators write:
“Participants with dual decline had 5.2 to 11.7 times higher risk of developing dementia, compared with usual agers.”
This impact remained important even after accounting for a range of factors, including existing health conditions and baseline walking velocities and memory capacity of the participants.
More work to come
Such results are significant, as early dementia care improves outcomes. Both gait speed and memory are easy to evaluate, neither measurement is technology-reliant and both cost-effectively. If further studies confirm such findings, it would be relatively simple to add those assessments to regular check-ups.
As written by the authors, dual decline could be “captured early in clinical settings by routinely administering gait speed evaluation and a free memory recall test.”
Future work should also address the issue of why — what factors underlie the double decline? The authors conclude that knowing why there is a correlation between dual loss and dementia may lead to future therapies or ways to prevent dementia from developing.
They also hope that additional research will explore “the different metabolic, vascular, and neuroimaging features that distinguish this particular group.”
Ultimately, the authors conclude that “Older people with dual memory and gait speed decline should receive additional treatment to address issues that may increase the risk of dementia, including cardiovascular and metabolic risk factor assessments.