Doctoral Thesis
Investigating the influence of physical activity and sleep on cognitive function in older adults
Doctor of Philosophy (PhD), Murdoch University
2023
Abstract
Dementia is one of the most feared illnesses in ageing, and with the prevalence of dementia set to increase, prevention of the disease is a public health priority. Up to 40% of dementia risk can be attributed to lifestyle factors; in particular, physical activity is associated with better cognition in ageing and a lower risk for developing dementia. Similarly, older adults with suboptimal sleep are at an increased risk for cognitive decline and Alzheimer’s disease (AD; the most common form of dementia). However, very little research has examined whether physical activity and sleep may interact to influence cognitive function. Further understanding the nature of the physical activity-sleep and cognition relationship is crucial for the development of effective, multi-modal lifestyle interventions for dementia prevention. Thus, this thesis aimed to further elucidate associations between physical activity, sleep and cognition. Based on a critical literature review, our first aim was to examine whether physical activity, exercise and sleep jointly, or independently influence cognition, and the nature of this relationship. We addressed this aim in all three studies, and our results indicated that there are some independent pathways through which sleep and cognition are associated (i.e., regardless of exercise; Study 2); however, physical activity and exercise may also compensate for some negative effects of suboptimal sleep on cognitive function (Studies 1 and 3). Our second aim was to examine whether these associations related to Alzheimer’s disease pathology, specifically levels of brain beta-amyloid (A), and we found that sleep and physical activity may interact to influence A (Study 1), however further research is required. Finally, we aimed to examine whether sleep is a mechanism through which exercise may influence cognition, and our results indicated that this effect did not exist within our sample, nor was there any effect of exercise on sleep or cognition (Study 2). Taken together, results from studies one and three indicate that physical activity and exercise may compensate for negative effects of suboptimal sleep on cognitive function. This thesis demonstrates that together, sleep and physical activity may play an important role in cognition in ageing, and highlight the need for further research in this area. Ultimately, results presented in this work may contribute to the development of individualised, targeted intervention strategies for dementia prevention.
Details
- Title
- Investigating the influence of physical activity and sleep on cognitive function in older adults
- Authors/Creators
- Kelsey Sewell
- Contributors
- Belinda Brown (Supervisor) - Murdoch University, Centre for Healthy AgeingJeremiah Peiffer (Supervisor) - Murdoch University, Centre for Healthy AgeingHamid Sohrabi (Supervisor) - Murdoch University, Centre for Healthy AgeingStephanie Rainey-Smith (Supervisor) - Murdoch University, Centre for Healthy AgeingKirk I. Erickson (Supervisor) - University of Pittsburgh
- Awarding Institution
- Murdoch University; Doctor of Philosophy (PhD)
- Identifiers
- 991005598469407891
- Murdoch Affiliation
- School of Allied Health
- Resource Type
- Doctoral Thesis
Metrics
113 File views/ downloads
217 Record Views