| dc.description.abstract | Objectives: Sedentary behavior may be both a cause and a consequence of cognitive decline in older adults. While previous literature provides plausible explanations for the relationship between sedentary behavior and cognition, research examining the directionality of this relationship is inconclusive. Little is known about how modality of sedentary behavior (e.g., screen time and non-screen time) is related to cognition. Individuals with dementia, a population known to have executive function impairment, have been found to sit more than their age and sex based counterparts. Therefore, the primary purpose of the present study was to investigate the potential bi-directional relationship between types of sedentary behavior and executive function in older adults with and without Alzheimer’s disease. Methods: One hundred community-dwelling older adults were recruited from an existing data registry at the University of Kansas Alzheimer’s Disease Center. In the present study, sedentary behavior data were collected over a one-week period using both objective (body worn inclinometers) and subjective methods (self-report diaries). Based on combining objective with subjective data, sedentary behavior modality was categorized into seven distinct categories which included screen based behaviors (television watching, computer use, multiple types of screen use, and other types of screen use), non-screen based behaviors, a combination of screen and non-screen behaviors, and unknown sedentary behaviors. Executive function was measured by creating a factor score comprised of four tests of executive function administered in a battery of neuropsychological tests. Linear stepwise regressions were used to assess directionality of the relationship between sedentary behavior and cognitive performance with age, sex, race, education level, body mass index, and dementia status used as covariates. Results: Only one type of sedentary behavior, the engagement in a combination of both screen and non-screen activities during a given 30-minute period, uniquely predicted higher executive function scores. Higher executive function scores also predicted more time spent in sedentary behavior periods that were made of up a combination of both screen and non-screen activities. Executive function performance contributed a larger degree of variance explained to sedentary behavior made up of a combination of both screen and non-screen activities than this form of sedentary behavior contributed to executive function. Conclusion: These findings suggest that older adults with executive function deficits may not be able to engage in periods of sedentary behavior that are made up of a combination of both screen and non-screen activities. The maintenance of executive function abilities may help engagement in this form in sedentary behavior. Our results suggest that interventions to decrease sedentary behavior in older adults may need to consider the type of sedentary behavior that they aim to change as well as the person’s executive function ability. | |
