title: Prolonged sitting may increase diabetes risk in physically inactive individuals: an 11 year follow-up of the HUNT Study, Norway.
abstract: We examined the association between sitting time and diabetes incidence, overall and by strata of leisure-time physical activity and BMI.
  
  
  
  We followed 28,051 adult participants of the Nord-Trøndelag Health Study (the HUNT Study), a population-based study, for diabetes incidence from 1995-1997 to 2006-2008 and estimated HRs of any diabetes by categories of self-reported total daily sitting time at baseline.
  
  
  
  Of 28,051 participants, 1253 (4.5%) developed diabetes during 11 years of follow-up. Overall, sitting ≥8 h/day was associated with a 17% (95% CI 2, 34) higher risk of developing diabetes compared with sitting ≤4 h/day, adjusted for age, sex and education. However, the association was attenuated to a non-significant 9% (95% CI -5, 26) increase in risk after adjustment for leisure-time physical activity and BMI. The association between sitting time and diabetes risk differed by leisure-time physical activity (pInteraction= 0.01). Among participants with low leisure-time physical activity (≤2 h light activity per week and no vigorous activity), sitting 5-7 h/day and ≥8 h/day were associated with a 26% (95% CI 2, 57) and 30% (95% CI 5, 61) higher risk of diabetes, respectively, compared with sitting ≤4 h/day. There was no corresponding association among participants with high leisure-time physical activity (≥3 h light activity or >0 h vigorous activity per week). There was no statistical evidence that the association between sitting time and diabetes risk differed by obesity (pInteraction= 0.65).
  
  
  
  Our findings suggest that total sitting time has little association with diabetes risk in the population as a whole, but prolonged sitting may contribute to an increased diabetes risk among physically inactive people.
authors.affiliation: HUNT Research Centre, Department of Public Health and General Practice, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Forskningsveien 2, N-7600, Levanger, Norway. bjorn.o.asvold@ntnu.no.|Department of Endocrinology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway. bjorn.o.asvold@ntnu.no.
authors.forename: Bjørn O
authors.initials: BO
authors.lastname: Åsvold
authors.affiliation: HUNT Research Centre, Department of Public Health and General Practice, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Forskningsveien 2, N-7600, 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, NTNU, Norwegian University of Science and Technology, Forskningsveien 2, N-7600, Levanger, Norway.
authors.forename: Steinar
authors.initials: S
authors.lastname: Krokstad
authors.affiliation: HUNT Research Centre, Department of Public Health and General Practice, Faculty of Medicine, NTNU, Norwegian University of Science and Technology, Forskningsveien 2, N-7600, Levanger, Norway.
authors.forename: Vegar
authors.initials: V
authors.lastname: Rangul
authors.affiliation: School of Public Health, Sydney University, Sydney, NSW, Australia.
authors.forename: Adrian
authors.initials: A
authors.lastname: Bauman
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000378:metabolism; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D015994:Incidence; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D057185:Sedentary Behavior
keywords: Epidemiology; Sedentary lifestyle; Type 2 diabetes mellitus