0091 Sleep as a Mediator of the Relationship Between Exercise and Self-Reported Cognitive Function

Abstract

Introduction: Insufficient sleep and sedentary behavior are associated with cognitive decline. How sleep and physical activity interact to influence cognition is not fully understood?. This study sought to examine whether self-reported sleep and exercise impact subjective cognitive complaints across adulthood. Method(s): Self-report questionnaire data from 2,744 adults (mu=56.18 yrs/old; 63.8% F; mu=16.36 yrs/edu) in the University of California Irvine Consent-to-Contact Registry were analyzed. Multiple regression models, analysis of covariance, and ordinary least squares path analysis were conducted to investigate relationships among the Cognitive Function Instrument (CFI), Medical Outcome Study Sleep Scale (MOS-SS) Subscales, and exercise frequency. All models adjusted for education, sex, age, BMI, medical comorbidities, depression, cancer diagnosis, and antidepressant usage. Individuals taking medications known to affect sleep or with a diagnosis major psychiatric illness were excluded from analyses. Result(s): All MOS-SS Subscales significantly predicted CFI score (all p<0.001). Individuals who exercise >3times/week had significantly lower scores on the CFI (p<0.05), Sleep Problems Index I & II (both p<0.05), Somnolence Subscale (p<0.01), and higher scores on the Sleep Adequacy Subscale (p=0.001). Mediation analyses revealed that all subscales, aside from the Sleep Disturbance Subscale, mediated the relationship between exercise frequency and CFI Score (Bootstrapped CI's did not include zero). Conclusion(s): More self-reported sleep disturbance and greater daytime sleepiness are associated with more subjective cognitive complaints. Individuals who exercise more frequently report lower daytime sleepiness and higher quality sleep. The effects of exercise frequency on cognitive complaints appear to be mediated by the impact of exercise on sleep. These results suggest that sleep health may be a crucial consideration when evaluating outcomes of exercise-based therapies aimed at delaying the onset of cognitive impairment.