title: Associations of overall sitting time and TV viewing time with fibrinogen and C reactive protein: the AusDiab study.
abstract: OBJECTIVE
  Sedentary behaviour is associated with increased risk for all-cause and cardiovascular mortality. Plasma fibrinogen and C reactive protein (CRP)-key inflammatory and/or haemostatic markers-may contribute to this association; however, few studies have examined their relationships with sedentary behaviours. We examined associations of overall sitting and TV viewing time with fibrinogen and high-sensitivity CRP (hsCRP).
  
  
  METHODS
  Plasma fibrinogen and hsCRP were measured in 3086 Australian adults (mean age: 55±12 years) who participated in the 2004-2005 AusDiab (Australian Diabetes, Obesity and Lifestyle) study. Multiple linear regression analyses examined cross-sectional associations of self-reported overall sitting and TV viewing time (h/day) with plasma fibrinogen and hsCRP, adjusting for sociodemographic, behavioural and medical treatments and conditions as potential covariates.
  
  
  RESULTS
  Overall sitting time and TV viewing time were positively associated with plasma fibrinogen (sitting: β: 0.02 g/L, 95% CI (0.01 to 0.02); TV time: 0.03 g/L (0.02 to 0.05)) and hsCRP (sitting: 2.4% (1.2% to 3.6%); TV time: 4.5% (1.7% to 7.4%)). Associations were independent of leisure-time physical activity, but after adjusting for waist circumference, they remained for fibrinogen, but for hsCRP were attenuated to the null. Interactions were observed for gender×TV (p=0.011) with fibrinogen (associations in women only) and for waist circumference×TV (p=0.084) with hsCRP (associations in low-risk only).
  
  
  CONCLUSIONS
  Overall sitting time was positively associated with plasma fibrinogen and hsCRP in men and women; associations of TV viewing time with fibrinogen were observed in women only. Abdominal adiposity-mediated associations for hsCRP but not for fibrinogen. Prospective and intervention studies are needed to establish likely causality and elucidate potential mechanisms.
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia School of Public Health & Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Bethany J
authors.initials: BJ
authors.lastname: Howard
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia INSERM CESP U1018, Villejuif, France Univ Paris-Sud, UMRS 1018, Villlejuif, France.
authors.forename: Beverley
authors.initials: B
authors.lastname: Balkau
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia School of Public Health & Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Alicia A
authors.initials: AA
authors.lastname: Thorp
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia School of Public Health & Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Dianna J
authors.initials: DJ
authors.lastname: Magliano
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Shaw
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia School of Population Health, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Neville
authors.initials: N
authors.lastname: Owen
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia School of Public Health & Preventive Medicine, Monash University, Melbourne, Victoria, Australia School of Population Health, The University of Queensland, Brisbane, Queensland, Australia School of Sport Science, Exercise & Health, University of Western Australia, Perth, Western Australia, Australia School of Exercise & Sports Science, Deakin University, Melbourne, Victoria, Australia.
authors.forename: David W
authors.initials: DW
authors.lastname: Dunstan
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D057185:Sedentary Behavior; D013690:Television; D013997:Time Factors; D055105:Waist Circumference
chemical_list: D015415:Biomarkers; D005340:Fibrinogen; D002097:C-Reactive Protein