Physical activity and sleep are each independently associated with brain function during an inhibitory task: Cross‐sectional results from the monitor‐OA study

Abstract

AbstractBackgroundThere is a growing body of evidence that sleep and physical activity (PA) are critical for the maintenance of brain functions that decline with age. However, few studies have examined how these lifestyle factors are independently associated with brain function. To this end, we investigated the associations of objectively‐measured PA and sleep with patterns of activation in the brain during an executive performance task using baseline data from a randomized controlled trial (RCT).MethodsAt baseline, we measured PA and sleep for 7 days using the SenseWear Mini in 61 participants. A subset of the RCT participants (n= 29) underwent a 3T MRI scan, during which we examined brain activation patterns using the Go/No‐Go executive performance task. We contrasted brain activation patterns during the GO and NOGO conditions (i.e., NOGO – Go) of accurate trials. We then performed three separate models (each controlling for age, sex, and education) wherein we examined the associations of brain activation during an inhibitory task with: 1) PA; 2) sleep duration; and 3) sleep efficiency (i.e., ratio of time spent sleeping to time spent trying to sleep). Significant clusters were corrected for multiple comparisons (p< 0.05) to determine region‐specific activation patterns.ResultsTable 1 describes our participants at baseline. Participants had a mean age of 61 years (SD= 9 years), and 79% were female. We determined that greater PA was associated with greater blood‐oxygen‐level dependent (BOLD) signal activity in the insular cortex (Figure 1A). Longer sleep duration was associated with increased BOLD signal activity in the precuneus, lingual gyrus, and lateral occipital cortex (Figure 1B). However, we did not find that sleep efficiency was associated with greater BOLD signal activity in any brain region.ConclusionsPA and sleep duration are each associated with greater brain activation in regions which are 1) associated with executive performance; and 2) susceptible to age‐associated decline. However, sleep efficiency does not appear to be related to brain activity patterns associated with executive functions.