title: Modeling how substitution of sedentary behavior with standing or physical activity is associated with health-related quality of life in colorectal cancer survivors.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Epidemiology, GROW School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. eline.vanroekel@maastrichtuniversity.nl.
authors.forename: Eline H
authors.initials: EH
authors.lastname: van Roekel
authors.affiliation: Department of Epidemiology, GROW School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors.forename: Martijn J L
authors.initials: MJ
authors.lastname: Bours
authors.affiliation: Department of Epidemiology, GROW School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors.forename: José J L
authors.initials: JJ
authors.lastname: Breedveld-Peters
authors.affiliation: Department of Human Movement Science, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University, Maastricht, The Netherlands.
authors.forename: Paul J B
authors.initials: PJ
authors.lastname: Willems
authors.affiliation: Department of Human Movement Science, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University, Maastricht, The Netherlands.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Meijer
authors.affiliation: Department of Epidemiology, CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands.
authors.forename: Ijmert
authors.initials: I
authors.lastname: Kant
authors.affiliation: Department of Epidemiology, GROW School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors.forename: Piet A
authors.initials: PA
authors.lastname: van den Brandt
authors.affiliation: Department of Surgery, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Geerard L
authors.initials: GL
authors.lastname: Beets
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht, The Netherlands.
authors.forename: Silvia
authors.initials: S
authors.lastname: Sanduleanu
authors.affiliation: Department of Epidemiology, GROW School for Oncology and Developmental Biology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors.forename: Matty P
authors.initials: MP
authors.lastname: Weijenberg
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000534:rehabilitation*; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009426:Netherlands; D011788:Quality of Life; D057185:Sedentary Behavior; D017741:Survivors
keywords: Colorectal cancer survivor; Health-related quality of life; Isotemporal substitution modeling; Physical activity; Sedentary behavior; Standing