A new study published Tuesday in JAMA Network Open found that a dual decline in walking speed and cognitive function "may be the best combination of clinical measures to identify people at risk of future dementia," Judy George reports for MedPage Today.

Study details and key findings

For the study, researchers analyzed data from 16,885 individuals who participated in the ASPREE trial of low-dose aspirin from 2010 to 2017 in the United States and Australia. The average age of study participants was 75, and 56% were women.

For each participant, the researchers measured a baseline gait speed when the trial began, then again at years two, four, six, and at the end of the study. They measured gait speed by asking participants to complete two walks of three meters each. A decline in gait speed was defined as a decrease in speed of at least 0.05 meters/second/year across the study.

At baseline and years one, three, five, and at the end of the study, each participant underwent four different cognitive assessments, including:

• The Modified Mini-Mental State Examination to gauge their global cognitive function
• The Hopkins Verbal Learning Test Revised to assess their memory
• The Controlled Oral Word Association Test to test verbal fluency
• The Symbol Digit Modalities Test to measure processing speed

Any measure that fell into the lowest tertile of annual change was considered cognitive decline.

When compared with individuals who did not experience any decline, dementia occurred most frequently in people who had declines in both gait speed and memory, followed by gait and global cognition, gait and verbal fluency, and gait and processing speed.

Commentary

According to the study authors, the analysis had some limitations. Gait and cognition were measured at separate points throughout the study, and ASPREE participants were generally healthier than many older adults, meaning the study's results might not translate well to other populations.

However, Taya Collyer of Monash University in Australia, an author of the study, and her co-authors, wrote, "Importantly, we answer the question as to whether dual decline in gait speed and a test of processing speed or verbal fluency exhibits a similar association with progression to dementia as decline in memory (delayed recall) or global cognition."

"Slowing gait and failing memory may be the best combination of clinical measures to identify people at risk of future dementia," said co-author Michele Callisaya of the National Center for Healthy Aging at Monash University and Peninsula Health.

"By the time a diagnosis of dementia is made, there's already been a substantial buildup of pathology in the brain," Callisaya said. "It's important to identify at-risk individuals early to address modifiable risk factors for dementia prevention and start new treatments as they become available."

"Gait speed is quick to measure and only requires a measured distance and a stopwatch," she noted. "Slowing of more than 0.05 meters per second per year should trigger a more comprehensive assessment."

According to Joe Verghese of Albert Einstein College of Medicine, gait evaluations are not typically performed in clinics.

"Despite the established predictive validity of gait assessments for geriatric syndromes, an implementation barrier for routine gait assessment in clinics exists that needs to be addressed to improve care of older patients," Verghese said.

"However, systematic longitudinal studies and finer-grain analysis of gait performance in the context of cognitive decline is calling this view into question," he wrote. (George, MedPage Today, 6/1; Collyer et al., JAMA Network Open, 5/31)