title: Sedentary behaviour and risk of mortality from all-causes and cardiometabolic diseases in adults: evidence from the HUNT3 population cohort.
abstract: BACKGROUND
  Sedentary behaviour is a potential risk factor for chronic-ill health and mortality, that is, independent of health-enhancing physical activity. Few studies have investigated the risk of mortality associated with multiple contexts of sedentary behaviour.
  
  
  OBJECTIVE
  To examine the prospective associations of total sitting time, TV-viewing time and occupational sitting with mortality from all causes and cardiometabolic diseases.
  
  
  METHODS
  Data from 50,817 adults aged ≥20 years from the Nord-Trøndelag Health Study 3 (HUNT3) in 2006-2008 were linked to the Norwegian Cause of Death Registry up to 31 December 2010. Cox proportional hazards models examined all-cause and cardiometabolic disease-related mortality associated with total sitting time, TV-viewing and occupational sitting, adjusting for multiple potential confounders including physical activity.
  
  
  RESULTS
  After mean follow-up of 3.3 years (137,315.8 person-years), 1068 deaths were recorded of which 388 were related to cardiometabolic diseases. HRs for all-cause mortality associated with total sitting time were 1.12 (95% CI 0.89 to 1.42), 1.18 (95% CI 0.90 to 1.57) and 1.65 (95% CI 1.24 to 2.21) for total sitting time 4-<7, 7-<10 and ≥10 h/day, respectively, relative to <4 h/day after adjusting for confounders (p-trend=0.001). A similar pattern of associations was observed between total sitting time and mortality from cardiometabolic diseases, but TV-viewing time and occupational sitting showed no or borderline significant associations with all-cause or cardiometabolic disease-related mortality over the same follow-up period.
  
  
  CONCLUSIONS
  Total sitting time is associated with all-cause and cardiometabolic disease-related mortality in the short term. However, prolonged sitting in specific contexts (ie, watching TV, at work) do not adversely impact health in the same timeframe. These findings suggest that adults should be encouraged to sit less throughout the day to reduce their daily total sitting time.
authors.affiliation: Prevention Research Collaboration, Sydney School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: Josephine Y
authors.initials: JY
authors.lastname: Chau
authors.affiliation: Prevention Research Collaboration, Sydney School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: Anne
authors.initials: A
authors.lastname: Grunseit
authors.affiliation: HUNT Research Centre, Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Levanger, Norway.
authors.forename: Kristian
authors.initials: K
authors.lastname: Midthjell
authors.affiliation: HUNT Research Centre, Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Levanger, Norway.
authors.forename: Jostein
authors.initials: J
authors.lastname: Holmen
authors.affiliation: HUNT Research Centre, Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Levanger, Norway.
authors.forename: Turid Lingaas
authors.initials: TL
authors.lastname: Holmen
authors.affiliation: Prevention Research Collaboration, Sydney School of Public Health, University of Sydney, Sydney, Australia.
authors.forename: Adrian E
authors.initials: AE
authors.lastname: Bauman
authors.affiliation: Prevention Research Collaboration, Sydney School of Public Health, University of Sydney, Sydney, Australia Department of Public and Occupational Health, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Hidde P
authors.initials: HP
authors.lastname: Van der Ploeg
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D008659:Metabolic Diseases / Q000401:mortality*; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D016272:Occupational Health / Q000706:statistics & numerical data; D011446:Prospective Studies; D012307:Risk Factors; D057185:Sedentary Behavior; D017678:Sex Distribution; D055815:Young Adult
keywords: Epidemiology; Health promotion through physical activity