Changes in daily activity patterns may help predict cognitive decline in older adults

Wearable motion-tracking devices may one day be useful in providing early warnings of cognitive decline in older adults, new findings from researchers at the Johns Hopkins Bloomberg School of Public Health suggest.

Researchers analyzed data from ActiGraph activity monitors, which use an activity-tracking sensor similar to those found in Fitbits and Apple watches, worn by nearly 600 participants in a long-running community-based study on the health of older adults. .

They found significant differences in movement patterns between participants with normal cognition and those with mild cognitive impairment or Alzheimer’s disease. These differences included less activity during waking hours and more fragmented afternoon activity in participants with mild cognitive impairment/Alzheimer’s disease.

The results were published on July 19 in the Alzheimer’s Disease Journal.

We tend to think of physical activity as a potential therapy to slow cognitive decline, but this study reminds us that cognitive decline can in turn slow physical activity; and we may one day be able to monitor and detect these changes for earlier and more effective testing. to delay and possibly prevent cognitive impairment that leads to Alzheimer’s disease.”

Amal Wanigatunga, PhD, MPH, Study Lead Author and Adjunct Scientist, Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health

The recent introduction of wearable activity tracking devices, which are now used by tens of millions of people around the world, has presented health researchers with an important opportunity to measure and track changes in physical movement.

The devices can provide automatic, objective measurements of daytime physical activity, sleep patterns, heart rate, and blood oxygen levels; and they are usually connected to the internet, which allows their makers to create datasets covering millions of users. Previously, researchers did not have such an easy way to access such health-relevant data on such a large scale.

The aim of the new study was to determine whether activity tracking patterns recorded from a cohort of older adults differ significantly between cognitively normal and cognitively impaired people. Alzheimer’s disease, the most common form of dementia, is known to be a decades-long process, and researchers generally expect future disease-modifying interventions to be more effective when started earlier. early in the course of the disease.

If scientists could identify a distinct change in activity that predicts the slide into mild cognitive impairment and, eventually, Alzheimer’s disease and other forms of dementia, then, in principle, older people who exhibit this change in activity could undergo additional cognitive testing – and, when available, earlier treatment.

The study used data from a larger, ongoing health research project known as the Baltimore Longitudinal Study of Aging (BLSA), in which the National Institute of Aging studied thousands of people in the Baltimore area since 1958. The analysis was based on 585 BLSA participants for whom sufficient activity tracking data and cognitive assessments were available during the period July 2015 through December 2019. There were 36 participants with mild cognitive impairment or a diagnosis of Alzheimer’s disease.

Adjusting for differences for age, gender, and race, the researchers found that overall differences in daily activity measures were not significantly different between the mild cognitive impairment/Alzheimer’s and Alzheimer’s groups. normal cognition. However, when the researchers focused on activity patterns at certain times of the day, some differences were revealed.

In the morning (6 a.m. to noon) and even more so in the afternoon (noon to 6 p.m.), the mild cognitive impairment/Alzheimer’s group had significantly lower activity measures compared to the normal group. The most striking finding was that activity “fragmentation” – a breakdown of activity into shorter periods – was 3.4% higher for participants with mild cognitive impairment/Alzheimer’s over the period. of the afternoon.

“Seeing this difference in the afternoon was interesting – one of the main symptoms of Alzheimer’s dementia is the ‘sunset’ phenomenon involving increased confusion and mood swings that start in the afternoon, and it may be that these activity markers are capturing some movement related to these symptoms,” says Wanigatunga.

The results, he notes, are preliminary due to the cross-sectional and “instantaneous” nature of the study design, although they support the idea that cognitive decline to mild cognitive impairment and dementia s accompanies changes in business patterns.

He and his colleagues plan additional studies that will follow participants over time, to see if measurable but mild changes in daily activity patterns help capture the early symptomatology of mild cognitive impairment and subsequent dementia of the Alzheimer’s disease.


Journal reference:

Wanigatunga, AA, et al. (2022) Patterns of daily physical activity as a window to cognitive diagnosis in the Baltimore Longitudinal Study of Aging (BLSA). Alzheimer’s Disease Journal.

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