Relationship Between Cognitive Performance, Physical Activity, and Socio-Demographic/Individual Characteristics Among Aging Americans.

Abstract

Physical activity (PA) has emerged as a promising approach to delay Alzheimer's disease and related dementias, but the optimal intensity of PA to improve cognitive health remains unknown. To evaluate the association between duration and intensity of PA and cognitive domains (executive function, processing speed, and memory) in aging Americans. Linear regressions in hierarchical blocks for variable adjustment and the size of effect (η2) were analyzed by using the data of 2,377 adults (age = 69.3±6.7 years) from the NHANES 2011-2014. Participants with 3-6 h/week of vigorous- and > 1 h/week of moderate-intensity PA scored significantly higher in executive function and processing speed domains of cognition compared to inactive peers (η2 = 0.005 & 0.007 respectively, p < 0.05). After adjustment, the beneficial effects of 1-3 h /week of vigorous-intensity PA became trivial for delayed recall memory domain test scores (β= 0.33; 95% CI: -0.01,0.67; η2 = 0.002; p = 0.56). There was no linear dose-response relationship between the cognitive test scores and weekly moderate-intensity of PA. Interestingly, higher handgrip strength and higher late-life body mass index were associated with a higher performance across all cognitive domains. Our study supports habitual PA with superior cognition health in some but not all domains among older adults. Furthermore, increased muscle strength and higher late-life adiposity may also impact cognition.