title: Adverse associations of increases in television viewing time with 5-year changes in glucose homoeostasis markers: the AusDiab study.
abstract: BACKGROUND
  Television viewing time is associated cross-sectionally with abnormal glucose tolerance and diabetes risk; however, the impact of changes in television viewing time on glycaemic measures is less understood. We examined relationships of 5-year change in television viewing time with 5-year change in glucose homeostasis markers.
  
  
  METHODS
  Participants in the Australian Diabetes, Obesity and Lifestyle study with data available at the 1999-2000 baseline and the 2004-2005 follow-up were included (4870; 45% men). Television viewing time (h/week) was assessed by questionnaire. Fasting plasma glucose, serum insulin and 2-h plasma glucose were obtained from an oral glucose tolerance test. Beta-cell function and insulin resistance were ascertained using the homeostasis model assessment 2-calculator. Associations of change in television viewing time with changes in glucose homeostasis markers were examined using linear regression models [β-coefficients (95% CI)]. Adjustments included baseline measures of age, television viewing time and glycaemic marker, and baseline and 5-year change in diet quality, energy intake, physical activity and waist circumference.
  
  
  RESULTS
  For every 5-h per week increase in television viewing time from baseline to 5-year follow-up, changes in glucose homeostasis markers were observed: among women there was a significant increase in fasting plasma glucose [0.01 (0.00-0.02) mmol/l] insulin resistance [0.03 (0.01-0.05)] and insulin secretion [1.07 (0.02-2.12) %]; insulin levels increased [men: 1.20 (0.30-2.09); women: 1.06 (0.32-1.80) pmol/l]; in men, 2-h plasma glucose levels increased [0.06 (0.01-0.1) mmol/l].
  
  
  CONCLUSIONS
  Five-year increases in television viewing time were associated adversely with changes in glucose homeostasis markers. These findings add to earlier cross-sectional evidence that television viewing time can be associated with biomarkers of diabetes risk.
authors.affiliation: Steno Diabetes Center A/S, Epidemiology Group, Gentofte, Denmark. asih@steno.dk
authors.forename: A L S
authors.initials: AL
authors.lastname: Hansen
authors.forename: K
authors.initials: K
authors.lastname: Wijndaele
authors.forename: N
authors.initials: N
authors.lastname: Owen
authors.forename: D J
authors.initials: DJ
authors.lastname: Magliano
authors.forename: A A
authors.initials: AA
authors.lastname: Thorp
authors.forename: J E
authors.initials: JE
authors.lastname: Shaw
authors.forename: D W
authors.initials: DW
authors.lastname: Dunstan
mesh_terms: D001315:Australia / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D015444:Exercise; D005215:Fasting; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000453:epidemiology*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D057185:Sedentary Behavior; D013690:Television; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D002784:Cholesterol; D006442:Glycated Hemoglobin; D014280:Triglycerides; C517652:hemoglobin A1c protein, human