Combined decline in gait and cognition may better predict dementia risk than either factor alone

Declining cognitive function coupled with slowed walking speed is associated with greater dementia risk in older adults than one of these factors alone, according to an NIA-funded study published in JAMA Network Open. The findings suggest that adding walking speed assessment to dementia risk screenings may help health care providers more accurately identify at-risk individuals. The study was led by an international team of researchers from the University of Minnesota, Rush University Medical Center, the University of Melbourne, and Monash University (Australia).

Today, there are 50 million people living with dementia worldwide, and this number is projected to triple by 2050. Decades before the symptoms of memory loss appear, many molecular and cellular changes take place in the brain of a person living with dementia. These changes are challenging to detect, so scientists are searching for simple tests that can help clinicians better identify individuals at high risk of developing dementia.

One test that may help is gait (walking) speed. Previous research demonstrated that declining gait speed is associated with dementia. Further, several earlier studies showed that a dual decline in both gait speed and cognitive function is a better predictor of dementia risk than either measure alone. However, these previous studies either included a small number of participants who developed dementia or had other limitations.

For this latest study, the research team examined dementia risk by analyzing data from the ASPirin in Reducing Events in the Elderly (ASPREE) clinical trial, a longitudinal study focused on aspirin use in older adults. ASPREE followed more than 17,000 adults older than age 65 from the United States and Australia from 2010 to 2017. Every two years, ASPREE researchers measured participants’ walking speed and administered tests that measured cognitive decline. They also determined whether participants met the criteria for a diagnosis of dementia.

The researchers also considered which cognitive measure was most useful for assessing dementia risk when combined with a decline in gait speed. They looked at data from four different types of cognitive tests, measuring overall cognition, memory, processing speed, and verbal fluency. The scientists found that when the metrics were combined, declining gait speed and worsening performance on the memory test best predicted future dementia risk. Further, the dual decline was better at predicting dementia risk than either measurement alone.

These results indicate that regularly testing both gait speed and memory may help health care providers more clearly identify patients at risk for dementia. Still, the authors note several limitations to their study, including that it did not distinguish between different types of dementia, and the participants were healthier than the general population. Overall, however, these findings highlight the importance of including gait assessment in routine dementia risk screens. Future studies could explore how to implement such testing in primary health clinics.

This research was supported in part by NIA grant U01AG029824.

Reference: Collyer TA, et al. Association of dual decline in cognition and gait speed with risk of dementia in older adults. JAMA Network Open. 2022;5(5), e2214647. doi: 10.1001/jamanetworkopen.2022.14647.