Study of more than 16,800 older Australians and Americans reveals slowing of gait and cognitive decline together is a predictor of dementia

A landmark study of more than 16,800 older people has found that a decline in both walking speed and cognition is a strong predictor of future dementia. The authors of the study, published in the prestigious Journal of the American Medical Association (JAMA) Open, suggest simple memory and walking speed testing, done in health clinics, may allow early preventive measures to be put in place to prevent the individual and global cost of diseases such as Alzheimer’s.

The study, led by Dr Taya Collyer and Associate Professor Michele Callisaya, from The National Centre for Healthy Ageing (NCHA) and Monash University Central Clinical School, along with the investigators from  the ASPirin in Reducing Events in the Elderly (ASPREE) Study used data from 16,855 Australian and US healthy people over the age of 65. Their gait, or walking speed, was measured at zero, two, four and six years after beginning the study, together with measurements of their cognition such as memory and verbal fluency tests.

Compared to those in the study for whom neither cognition nor gait declined, the risk of dementia was greatest in those whose gait and performance on cognition tests both declined compared to those with these individual declines.

There will be more than 150 million people living with dementia by 2050, at a cost of $1.6 trillion US so it is important to be able to predict those at risk of the disease and to provide them with preventive interventions such as exercise, controlling blood pressure and a healthy diet.

While slow gait speed has been associated with cognitive decline and an increased risk of dementia, and, some studies linking slow gait and subjective cognitive decline with dementia, according to Associate Professor Callisaya “This is the largest study to test the synergistic impact of both cognitive decline and reduction in gait as a predictor of dementia – specifically comparing objective measures of global cognition, processing speed, memory and verbal fluency,” she said.

The participants, over 70 or over 65 if from a minority, were recruited from 2010-2014 in the US and Australia. All were free of cardiovascular disease, dementia or physical disability at the start of the study. Gait speed was measured at face-to-face visits at zero, two, four, six and at a close out visit at the end of the study. Each participant completed two walks of three metres at usual pace from a standing start with an additional one meter at the end to prevent slowing.

The study measured annual changes in cognition and gait across the study period as well as a rigorous assessment of dementia. “We examined associations between dual (combined) decline in gait speed and measures of cognition together with a diagnosis of dementia,” Dr Collyer said. “We found that the dual decline of gait speed and cognitive measurements is associated with a higher risk of dementia compared to non-decliners, or cognitive decliners only or gait decliners only.”

The authors, who include Professor Anne Murray, from the Berman Center for Outcomes and Clinical Research at the University of Minnesota, state that serial measurement of gait along with a simple tests of memory may be a more sensitive predictor for future dementia than either measure alone, with such testing feasible in primary health clinics, with a view to introducing early preventative measures.

About The National Centre for Healthy Ageing (NCHA)

The National Centre for Healthy Ageing (NCHA) is Australia's premier healthy ageing research centre committed to the transformation of health and care of our ageing communities.

A partnership between Monash University and Peninsula Health, the NCHA brings together the very best researchers from a variety of health disciplines to co-design research to help solve some of the greatest challenges facing our ageing population.

A  new research agenda will see the centre invest over $7 million dollars in new healthy ageing research over the coming year.