Life space changes linked to cognitive decline, risk of neurodegenerative illness

Key takeaways:

• The study included 1,864 U.S.-based community-dwelling older adult men.
• Clinical assessments and wearable trackers could have a future role in measuring cognitive or physical decline.

For older adult males, negative changes in life space were associated with faster cognitive decline and increased risk for neurodegenerative disorders after 7 years, according to research from JAMA Network Open.

“There is increasing interest in life space as a more holistic measure of everyday function than typical self-reported measures of disability, which measure capacity for movement rather than actual enacted mobility,” Meredith A. Bock, MD, assistant professor in the department of neurology at the Weill Institute for Neurosciences at the University of California, San Francisco, and colleagues wrote.

Bock and colleagues aimed to evaluate the association between changes in life space and cognitive decline or incident neurodegenerative disease over 7 years in community-dwelling older men.

Their prospective cohort study drew enrollees and data from the Osteoporotic Fractures in Men Study (MrOS), which included nearly 6,000 independently living older adults recruited from six U.S.-based locations between 2007 and 2014, with follow-ups thereafter. At baseline, 3,892 participants had a life space assessment with 2,116 of those undergoing a second assessment 7 years later. A total of 1,864 adult men (mean age 77.1 years) were admitted for analysis.

Life space was measured via the University of Alabama at Birmingham Life Space Assessment, a multifaceted diagnostic tool which asks individuals to record their movement both inside and outside their homes, frequency of movement and level of independence for daily activities.

The primary outcome was scoring on a completed Modified Mini-Mental State (3MS) Test, as well as the Trail-Making Test Part B at baseline and 7 years later. During follow-up, participants were asked about any new physician-based diagnosis of dementia and Parkinson’s disease.

Logistic regression analyses were utilized to examine the association of baseline and change in life space with change in cognition unadjusted and adjusted for a host of factors. Mixed linear effects models were also employed to evaluate the association between change in life space and cognition.

Over 7 years of follow-up, researchers found that 80 participants developed dementia and 23 developed PD, while mean life space score was 92.9 points at baseline and mean change was 9.9 points over the 7-year follow up.

In the adjusted model, each standard deviation of one decrement in life space was associated with increased odds of dementia (OR = 1.59; 95% CI, 1.28-1.98) but not PD (OR = 1.48; 95% CI, 0.97-2.25). For each 1-SD decrement in life space, participants worsened by 20.6 seconds (95% CI, 19.8-21.1) in their Trails B score and declined by 1.2 points (95% CI, 1.0-1.3) in their 3MS score over 7 years.

“This study can also inform ongoing efforts to collect data with wearable electronics in older adults, as changes within the same individual over time may have higher predictive value than baseline assessments,” Bock and colleagues wrote.