title: Prospective association of TV viewing with acute phase reactants and coagulation markers: English Longitudinal Study of Ageing.
abstract: OBJECTIVE
  Inflammatory processes are putative mechanisms underlying the detrimental health effects of sedentary behaviour but no long-term prospective data are available. We examined the longitudinal association between TV viewing, physical activity and inflammatory markers over a 4-year follow-up period.
  
  
  METHODS
  Participants were 3612 men and women (mean age 64.1 ± 8.2 years) from the English Longitudinal Study of Ageing. Self-reported daily TV viewing was measured at baseline and 2 years follow up. Inflammatory markers (serum high-sensitivity C-reactive protein [CRP], white blood cell count [WBC], and fibrinogen) were measured at baseline (2008/09) and 4 years follow-up (2012/13).
  
  
  RESULTS
  On average, participants viewed TV for 5.1 ± 4.0 h/d, and there was an increase of 1.9 h/wk TV viewing over 2 years. In linear models adjusted for covariates including physical activity, TV viewing was not associated with logeCRP at follow-up (B = 0.004, 95% CI, -0.001, 0.009, p = 0.09) but was associated with WBC (B = 0.018, 95% CI, 0.005, 0.031, p = 0.006), and fibrinogen (B = 0.004, 95% CI, 0.00, 0.008, p = 0.035). In contrast, physical activity was inversely associated with CRP (p = 0.047) and WBC (p = 0.026), but not fibrinogen (p = 0.22). An increase in TV viewing (of at least 1 h/d) was associated with higher concentrations of CRP (p = 0.015) and WBC (p = 0.05) at follow up after adjustment for covariates and baseline TV viewing.
  
  
  CONCLUSIONS
  Physical activity and sedentary behaviour have contrasting associations with markers of low grade inflammation over 4 years of follow-up. These behaviours may be important in influencing the pro-inflammatory state seen with ageing.
authors: Physical Activity Research Group, Department of Epidemiology and Public Health, University College London, UK. Electronic address: m.hamer@ucl.ac.uk.
authors: Mark
authors: M
authors: Hamer
authors: Physical Activity Research Group, Department of Epidemiology and Public Health, University College London, UK; Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK.
authors: Lee
authors: L
authors: Smith
authors: Physical Activity Research Group, Department of Epidemiology and Public Health, University College London, UK; Prevention Research Collaboration, Sydney School of Public Health, University of Sydney, Australia; Charles Perkins Centre, University of Sydney, Australia; Exercise and Sports Science, Faculty of Health Sciences, University of Sydney, Australia.
authors: Emmanuel
authors: E
authors: Stamatakis
mesh_terms: D000210:Acute-Phase Reaction; D000368:Aged; D000375:Aging; D001777:Blood Coagulation; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000503:physiopathology*; D004739:England; D015444:Exercise; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D007962:Leukocytes / Q000166:cytology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D057185:Sedentary Behavior; D013690:Television
chemical_list: D005340:Fibrinogen; D002097:C-Reactive Protein
keywords: Adiposity; Blood coagulation; Exercise; Inflammation; Sedentary lifestyle