According to recent research from the Johns Hopkins Bloomberg School of Public Health, wearable movement-tracking technologies may one day be helpful in giving older persons early signs of cognitive loss.

This study was published in the Journal of Alzheimer s Disease. Nearly 600 participants in a long-running community-based health study of older persons wore ActiGraph activity monitors, which use an activity-tracking sensor similar to those found in Fitbits and Apple watches.

Between people with normal cognition and those who had mild cognitive impairment or Alzheimer's disease, they discovered substantial variations in movement patterns. Among the subjects with mild cognitive impairment/ Alzheimer's, these variations included less activity during waking hours and more fragmented activity during afternoons.

According to study lead author Amal Wanigatunga, PhD, MPH, assistant scientist in the Department of Epidemiology at the Bloomberg Sackler School of Public Health, "We tend to think of the physical activity as a potential therapy to slow cognitive decline, but this study reminds us that cognitive decline may in turn slow physical activity and we might someday be able to monitor and detect such changes for earlier and more efficient testing to delay and maybe prevent cognitive impairment that leads to Alzheimer's."

Health researchers now have a critical chance to measure and follow changes in physical movement because of the recent advent of wearable activity-tracking devices, which are being used by tens of millions of individuals worldwide.

The gadgets may automatically and objectively assess a user's blood oxygen levels, heart rate, sleep patterns, and physical activity levels during the day. They are often Internet-connected, which enables their creators to compile databases of millions of users. A significant volume of easily accessible health-related data was not previously available to researchers.

The objective of the current study was to ascertain whether activity-tracker patterns recorded from a sample of older persons who were cognitively normal and cognitively impaired differed significantly.

Researchers usually anticipate that future disease-modifying therapies will be more effective when initiated earlier in the disease course because Alzheimer's disease, the most prevalent form of dementia, is known to be a debilitating process that takes decades to develop.

In theory, older people who exhibit this change in activity could receive additional cognitive testing and, when available, earlier treatment--if researchers could pinpoint a distinct change in activity that predicts the progression into mild cognitive impairment and, eventually, Alzheimer's and other forms of dementia.

The National Institute on Aging has been researching thousands of adults in the Baltimore area since 1958 as part of a broader, continuing health research effort known as the Baltimore Longitudinal Study of Aging (BLSA). Based on 585 BLSA participants for whom sufficient activity-tracker data and cognitive evaluations were available between July 2015 and December 2019, the study was conducted.

These included 36 participants who had been given an Alzheimer's or mild cognitive impairment diagnosis. The researchers discovered that overall disparities in all-day activity measures between the moderate cognitive impairment/and Alzheimer's normal cognition groups were not significantly different after adjusting for variances based on age, sex, and race. However, some variations were found when the researchers concentrated on activity patterns at particular times of the day.

The mild cognitive impairment/group Alzheimer's had significantly lower levels of activity throughout the morning (6 a.m. to noon) and much more so during the afternoon (noon to 6 p.m.) than the normal group.

The most startling result was that the mild cognitive impairment/individuals with Alzheimer's experienced activity "fragmentation" a breaking-up of activities into smaller time periods--3.4 per cent more frequently in the afternoon.

"Seeing this difference in the afternoons was interesting--one of the key symptoms of Alzheimer's dementia is the sundowning phenomenon, which involves increased confusion and mood swings that begin in the afternoon, and it might be that these activity markers are catching some movement related to these symptoms," Wanigatunga says.

He points out that although the results are preliminary due to the cross-sectional, "snapshot" nature of the study design, they do support the notion that changes in activity patterns occur together with a cognitive decline into mild cognitive impairment and dementia.

To determine whether detectable yet subtle changes in daily activity patterns can help identify early symptoms of mild cognitive impairment and future Alzheimer's disease dementia, he and his colleagues are planning more research that will track participants over time.