Search

Introduction: Given the growing population of colorectal cancer (CRC) survivors, identifying ways to enhance health-related quality of life (HRQoL) and alleviate complaints of fatigue and chemotherapy-induced peripheral neuropathy (CIPN) is essential., Purpose: We aimed to assess longitudinal associations of sedentary behavior (SB) and moderate to vigorous physical activity (MVPA) independently, as well as their joint association, with HRQoL, fatigue, and CIPN in CRC survivors., Methods: In a prospective cohort among stage I-stage III CRC survivors (n = 396), five repeated home visits from diagnosis up to 24 months posttreatment were executed. SB was measured using triaxial accelerometers, and MVPA, HRQoL, fatigue, and CIPN were measured by validated questionnaires. We applied confounder-adjusted linear mixed models to analyze longitudinal associations from 6 wk until 24 months posttreatment., Results: Average time in prolonged SB (accumulated in bouts of duration ≥30 min) was 5.3 ± 2.7 h·d-1, and approximately 82% of survivors were classified as sufficiently active (≥150 min·wk-1 of MVPA) at 6 wk posttreatment. Decreases in SB and increases in MVPA were independently associated with better HRQoL and less fatigue over time. No associations were found for CIPN complaints. A synergistic interaction was observed between prolonged SB and MVPA in affecting functioning scales. Relative to CRC survivors with low prolonged SB and high MVPA, survivors with high prolonged SB and low MVPA reported a stronger decrease in physical functioning and role functioning over time than expected based on the independent associations of prolonged SB and MVPA., Conclusion: Our longitudinal results show that less SB and more MVPA are beneficial for CRC survivors' HRQoL and fatigue levels. Our findings regarding interaction underscore that joint recommendations to avoid prolonged sitting and accumulate MVPA are important., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Sports Medicine.)

Background: Recent updates to physical activity guidelines highlight the importance of reducing sedentary time. However, at present, only general recommendations are possible (ie, "Sit less, move more"). There remains a need to investigate the strength, temporality, specificity, and dose-response nature of sedentary behavior associations with chronic disease, along with potential underlying mechanisms., Methods: Stemming from a recent research workshop organized by the Sedentary Behavior Council themed "Sedentary behaviour mechanisms-biological and behavioural pathways linking sitting to adverse health outcomes," this paper (1) discusses existing challenges and scientific discussions within this advancing area of science, (2) highlights and discusses emerging areas of interest, and (3) points to potential future directions., Results: A brief knowledge update is provided, reflecting upon current and evolving thinking/discussions, and the rapid accumulation of new evidence linking sedentary behavior to chronic disease. Research "action points" are made at the end of each section-spanning from measurement systems and analytic methods, genetic epidemiology, causal mediation, and experimental studies to biological and behavioral determinants and mechanisms., Conclusion: A better understanding of whether and how sedentary behavior is causally related to chronic disease will allow for more meaningful conclusions in the future and assist in refining clinical and public health policies/recommendations.

Introduction: Physical activity may affect health via DNA methylation. The epigenetic influences of sedentary behaviors such as television viewing are unknown. We performed a genomewide study of DNA methylation in peripheral blood in relation to physical activity and television viewing time., Methods: DNA methylation was measured using the Illumina Infinium HumanMethylation450K BeadChip array in blood samples collected at baseline (N = 5513) and follow-up (N = 1249) from participants in the Melbourne Collaborative Cohort Study. At baseline, times per week of leisure-time physical activity were self-reported. At follow-up, the International Physical Activity Questionnaire was used to assess MET-hours per week of total and leisure-time physical activity and hours per day of television viewing time. Linear mixed models were used to assess associations between physical activity and television viewing measures and DNA methylation at individual CpG sites, adjusted for potential confounders and batch effects., Results: At follow-up, total physical activity was associated with DNA methylation at cg10266336 (P = 6.0 × 10), annotated to the SAA2 gene. Weaker evidence of associations (P < 1.0 × 10) were observed for an additional 14 CpG sites with total physical activity, for 7 CpG sites with leisure-time physical activity, and for 9 CpG sites with television viewing time. Changes in leisure-time physical activity between baseline and follow-up were associated with methylation changes (P < 0.05) at four of the seven CpG sites with weaker evidence of cross-sectional associations with leisure-time physical activity., Conclusion: Physical activity and television viewing may be associated with blood DNA methylation, a potential pathway to chronic disease development. Further research using accelerometer data and larger sample sizes is warranted.

Purpose: Previous research indicates that sedentary behavior is unfavorably associated with health-related quality of life (HRQoL) of colorectal cancer (CRC) survivors. Using isotemporal substitution modeling, we studied how substituting sedentary behavior with standing or physical activity was associated with HRQoL in CRC survivors, 2-10 years post-diagnosis., Methods: A cross-sectional study was conducted in stage I-III CRC survivors (n = 145) diagnosed at Maastricht University Medical Center+, the Netherlands (2002-2010). Sedentary, standing, and physical activity time were measured by the thigh-mounted MOX activity monitor. HRQoL outcomes comprised global quality of life, physical, role, and social functioning, and disability (scales: 0-100), fatigue (20-140), and depression and anxiety (0-21). Isotemporal substitution modeling was applied to analyze associations with HRQoL of substituting sedentary time with equal time in standing or physical activity., Results: On average, participants spent 10.2 h/day sedentary (SD, 1.7), 3.4 h/day standing (1.3), and 1.7 h/day in physical activity (0.8). In confounder-adjusted isotemporal models, substituting sedentary time with standing or with physical activity was associated with significantly better physical functioning (regression coefficient [β], i.e., difference in outcome score per 1 h/day of sedentary time substituted with standing or physical activity, 3.1; 95% confidence interval [CI] 0.5, 5.7; and 5.6; 0.7, 10.6, respectively). Substituting sedentary time with standing was also associated with significantly lower disability (β, -3.0; 95% CI -4.9, -1.1) and fatigue (-4.0; -7.6, -0.3)., Conclusions: Our results suggest that substituting sedentary behavior with standing or physical activity may be beneficially associated with certain HRQoL outcomes in CRC survivors. Prospective studies are warranted to confirm whether actual substitution of sedentary behavior with these activities may improve HRQoL in CRC survivors.