Sedentary behaviours and cognitive function in the older population
thesisposted on 2023-08-30, 20:26 authored by Olawale Olanrewaju
Older adults engage in high levels of sedentary behaviour. Average sedentary time ranges between 8-10 hours per day. High sedentary levels are associated with an increased risk of all-cause mortality, cardiovascular disease, cancer, and diabetes incidences. However, the link between sedentary behaviour and cognitive health is unclear with research showing mixed findings and a lack of intervention studies. It is particularly important to understand the association between sedentary behaviour and cognition because modifying risky behaviour and lifestyle could be pivotal to delay the onset of cognitive decline and ultimately dementia. The objectives of this thesis were to explore the associations between sedentary behaviour and cognitive function in older people using multi-method research designs: (1) Systematic review of extant studies to explore associations (2) Analyses of The Irish Longitudinal Study of Ageing (TILDA) to ascertain cross-sectional and longitudinal associations between sitting time and television viewing and three different cognitive outcomes (global, executive and memory) (3) Feasibility trial to assess the acceptability of a sedentary reducing intervention delivered via remote health coaching in an at-risk population, with a view to conducting a future full-scale trial. Findings from the systematic review informed the TILDA data analysis, which subsequently informed the intervention study. The systematic review demonstrated the need for more longitudinal studies and analysis. Findings from the TILDA analyses underlined the need for intervention studies and provided a rationale for elements of the feasibility trial design such as the choice of cognitive and device-measured sedentary outcome measures. Varying associations between different sedentary behaviours and cognitive function were found. However, television viewing was consistently related to poorer cognition. The intervention study demonstrated that the remote delivery of a sedentary reducing intervention underpinned by behavioural theory was feasible and acceptable in community-dwelling older adults living with Mild Cognitive Impairment. This thesis extends the work of others by confirming the detrimental association between excessive television viewing and cognition in older people and that a full-scale trial of complex behavioural intervention is feasible in a high-risk group. Public health policies aimed at discouraging the uptake of high sedentary levels, especially 2-3 hours / day of TV viewing, to promote good cognitive health among the older population should be promoted. A full-scale trial is now needed to confirm the effectiveness of reducing sedentary levels on health outcomes and related biomarkers.
InstitutionAnglia Ruskin University
- Accepted version