Time spent in physical activities, TV watching and sleep and its association with cognitive performance in middle age and older adults: an isotemporal substitution analysis

Introduction:  Physical activities, sedentary behavior and sleep time are interrelated across the 24-hour day cycle and are differentially associated with cognitive performance (CP).
Methods: Baseline data (≥40y) from Lifelines Cohort Study (n=58,582) was used to assess the association between self-reported TV-watching, diverse physical activities, and sleep with CP (Ruff Figural Fluency Test) using multivariable linear regression. Isotemporal substitution analyses were applied to estimate the impact of replacing time TV-watching by any other activity. Analyses were stratified by age (40-59y, and ≥60 years) and sleep duration (<7/7-8/>8 hours).
Results: Among normal sleepers (n=43,996) TV-watching was inversely associated with CP in middle-aged and older adults, and its 30 minutes substitution with either leisure, sports, household, or work significantly increased CP. Associations were less pronounced in short sleepers and absent among long sleepers ≥60 years.
Discussion: Replacing TV-watching time with other movement activities was beneficial for CP, but these associations were conditional upon age and sleep duration.