Longitudinal Association between Perceived Fatigability and Cognitive Function in Older Adults: Results from the Baltimore Longitudinal Study of Aging

Abstract

Cognitive decline is consistently associated with diminished life satisfaction and inability to live independently. Identifying early, novel markers of cognitive decline is imperative for improving clinical detection and promoting long-term quality of life. Fatigability, one's perceived exertion after a standardized walking task, has been associated with declines in physical function; however, it remains unclear as to whether these effects may also extend to cognitive function. Methods: We examined whether perceived fatigability, assessed as the rating of perceived exertion (RPE) after a 5 min slow-paced treadmill walk (0.67 m/s, 0% grade), is longitudinally associated with cognitive performance in the domains of memory, executive functions, language, and attention among 934 cognitively intact individuals aged at least 50 years participating in the Baltimore Longitudinal Study of Aging (BLSA); Mage = 69.6 ± 10.1, 51.9% female participants. Continuous associations between RPE and each domain (individual test and composite scores) were assessed using linear mixed-effect models adjusted for demographics and comorbid conditions. Results: In fully adjusted models, higher fatigability at baseline was associated with declines in all cognitive domains over an average 2.2 years of follow-up (p