Kuhn, Tara2025-08-202025-08-202025-08-202025-08-07https://hdl.handle.net/10012/22205Introduction: Sleep disturbance is not only associated with increased risk of dementia but is common after dementia onset and is a noted stressor for care partners. Physical activity may reduce dementia risk, as well as promote sleep for people with dementia. However, it is unclear whether physical activity and sleep interact to mitigate dementia risk or promote quality of life in people with dementia. This thesis aims to: 1A) understand the relationship between sleep, physical activity and cognitive function in people without dementia, and 1B) understand how sleep and physical activity relate to cognitive function and functional abilities among people with dementia, and 2) adapt a lifestyle-focused sleep intervention for Canadians with dementia. Aim 1: Data from the Rush Memory and Aging Project —which utilized accelerometers, a cognitive battery, and clinical expertise— was used to examine: how sleep and physical activity were associated with cognitive decline and dementia risk in people without cognitive impairment (Study 1); and how sleep and physical activity were associated with cognitive and physical function in people with dementia (Study 2). In Study 1, greater physical activity was associated with slower cognitive decline and reduced dementia risk. Additionally, more fragmented sleep was associated with worse baseline global cognition, but not cognitive trajectory or dementia incidence. In Study 2, physical activity was associated with better functional abilities, but not with cognitive trajectory or sleep fragmentation in people with dementia. Sleep fragmentation was not associated with global cognition or functional abilities among people with dementia. Aim 2: A lifestyle intervention for sleep (NITE-AD) that included sleep education, physical activity, and light therapy was adapted to be s appropriate for use in Canada (NITE-CAD). Based on the Knowledge to Action cycle, we approached this program adaptation in three steps. Step 1: identify the knowledge gap and determine availability of sleep programs for people with dementia in Canada. Step 2: assess the barriers and facilitators to knowledge use (Study 3) and determine which aspects of the program required requires modification. Using a qualitative descriptive design, semi-structured interviews were carried out with people with dementia and their care partners. Interviews were coded with a deductive content analysis, using the Behaviour Change Wheel as the guiding framework. Findings indicated winter conditions exacerbated previous challenging circumstances for people with dementia and winter physical activity participation was facilitated when people with dementia had appropriate equipment, access to facilities or cleared trails, and had their preferences met (e.g. indoor vs. outdoor activities, risk tolerance). Step 3 (Study 4) tailored the NITE-AD program with an advisory team using the results from Study 3 to create the NITE-CAD program. Changes included flexible physical activity options to support participation of people with dementia with diverse needs, contexts, and preferences, and minor wording and formatting changes. Conclusion: Sleep and physical activity were independently associated with cognitive functioning, with physical activity reducing cognitive decline and dementia risk in adults without dementia. However, the positive effect to cognitive function was not evident after dementia onset, although physical activity benefited functional abilities. Several barriers and facilitators for engaging in winter physical activity were identified for people with dementia, which should be kept in mind for future dementia interventions utilizing physical activity. Flexible options may be needed to accommodate the diverse preferences, abilities, and resources of people with dementia and care partners.ensleepphysical activitydementiaAlzheimer's diseaseco-designDoctoral Thesis