Domain-specific physical activity and sedentary behaviour in relation to colorectal cancer risk and survival
Year: 2019
Type: dissertation
Abstract: To my late mother She will always be in my thoughts and prayers analysis (Study 2).In CRC survivors (Study 4), the adjusted EMRRs comparing highest versus the lowest categories of pre-diagnosis recreational physical activity were 0.83 (95% CI: 0.42-1.64)and for higher recreational sedentary behaviour were 1.25 (95% CI:0.67-2.32).An inverse association was found between transport-related physical activity and colon cancer risk (RR= 0.66; 95% CI: 0.45-0.98) in my meta-analysis (Study 1).However, within the MCCS data (Study 2), a non-statistically significant association was noted with CRC risk when comparing highest versus the lowest physical activity (HR= 0.90; 95% CI: 0.68-1.19).Survival analyses (Study 4) suggest that CRC survivors who were active in transport-related activity before their diagnosis had a non-statistically significant 43% lower risk of excess mortality (EMRR= 0.57; 95% CI: 0.31-1.07).Higher household-related physical activity was not associated with lower risk of colon (RR= 0.85; 95% CI: 0.71-1.02)or rectal (RR= 1.01; 95% CI: 0.80-1.27)cancers in my metaanalysis (Study 1) and in the MCCS relative risk analysis (HR= 1.07; 95% CI: 0.82-1.40)(Study 2).Moreover, no reduction in mortality risk was found for higher pre-diagnosis activity in this domain for CRC survivors (Study 4).The quantitative bias analysis (Study 3) indicated that the estimated HRs for colorectal cancer risk (for high versus low levels of self-reported physical activity) in the MCCS before and after bias adjustment were HR= 0.95 (95% CI: 0.87-1.05)and HR= 0.78 (95% CI: 0.47-1.28),respectively. ConclusionsIncreasing the level of physical activity across multiple domains (occupation, recreation, transport) is associated with lower risk of CRC, whereas household activity had little or no association.Summary estimates also suggest that reducing sitting time within workplace could help lower the risk of CRC.In my validation study, it was demonstrated that the overvii estimation of self-reported physical activity attenuates measures of association.There may be survival benefits for increasing physical activity and reducing recreational sedentary behaviour, but estimates derived from MCCS are imprecise.viii
Author: Shahid Mahmood
Language: English
Topic: Physical Activity and Health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2951091134