Physical activity attenuates the effect of poor sleep quality on cognitive function in adults with chronic stroke

Abstract

AbstractBackgroundGood sleep quality is important for cognitive health. Individuals with chronic stroke are at an increased risk for dementia and about half have insomnia. Stroke survivors are a target population in need of intervention strategies to promote sleep quality to preserve cognitive function. Physical activity is a promising approach. Hence, in this cross‐sectional analysis, we examined whether physical activity moderates the effect of poor sleep quality on cognitive function in adults with chronic stroke.MethodThis is a cross‐sectional analysis of baseline data acquired from 121 community‐dwelling older adults with chronic stroke (age: 70.73 ± 8.56 years; 38.30% female) enrolled in a 6‐month randomized control trial. Sleep quality was assessed with the MotionWatch8 (MW8) and physical activity was measured with the Life Space Questionnaire (LSQ; 0‐120). Participants were split into higher or lower physical activity by the median LSQ score (median = 64.00). Cognitive performance was measured with the 13‐item Alzheimer’s Disease Assessment Scale (ADAS‐Cog; 0‐85), with higher scores indicating worse cognitive performance. A linear regression was performed to first assess the independent association of MW8‐measures of sleep quality (i.e., sleep duration, fragmentation, efficiency, latency, and awakenings) and ADAS‐Cog score, after accounting for age and Montreal Cognitive Assessment score (MoCA) score. Based on the results of this linear regression, we performed a second linear regression with ADAS‐Cog score as the dependent variable, and sleep latency (minutes), physical activity level, and the interaction of sleep latency * physical activity level as independent variables, controlling for age and MoCA score.ResultGreater sleep latency (β1 = 0.22, p = 0.017) was significantly associated with greater ADAS‐Cog score, after controlling for age and MoCA (R2 = .50, F(3, 105) = 34.74, p<.01). Physical activity significantly moderated the association between sleep latency (β1 = 0.38, p = 0.033) and ADAS‐Cog score (R2 = .53, F(5, 103) = 22.93, p<.01). Specifically, those in the higher physical activity group showed lower ADAS‐Cog scores with higher sleep latency (r = .67, p = .627) and those in the lower physical activity group showed higher ADAS‐Cog scores with higher sleep latency (r = .75, p = .007).ConclusionPhysical activity attenuates the effect of poor sleep quality on cognitive function in adults with chronic stroke.