title: Twelve-Year Television Viewing Time Trajectories and Physical Function in Older Adults.
abstract: The purposes of this study were to identify trajectories of older adults' television viewing (TV) time for 12 yr and to examine their associations with performance-based measures of physical function.
  
  
  
  Data on TV time (h·wk) and sociodemographic factors were collected at each assessment of the Australian Diabetes, Obesity and Lifestyle Study (1999/2000, 2004/2005, and 2011/2012), with objective measures of physical function (2.44 m timed up and go [TUG, s] and knee extensor strength [KES, kg] tests) collected at the final (2011/2012) assessment. Regression analyses examined predictors of trajectory membership and associations with TUG and KES in those 60+ yr of age in 2011/2012.
  
  
  
  Six TV time trajectories were identified among the 1938 participants (age, 60-97 yr; 54% female): consistently low (9.7%), low-increasing (22.3%), moderate-decreasing (13.5%), moderate-increasing (30.3%), consistently high (18.9%), and high-increasing (5.2%). There were no statistically significant relationships with TUG (P > 0.05). In the fully adjusted model, KES performance was significantly better in the consistently low, low-increasing, and consistently high trajectories, compared with the moderate-increasing trajectory (P < 0.001, R = 0.33).
  
  
  
  Twelve-year trajectories of TV time were associated with muscle strength in older adults. These findings suggest that patterns of sedentary behavior can be a determinant of muscle strength in later life.
authors.affiliation: 1School of Public Health, The University of Queensland, Brisbane, AUSTRALIA; 2School of Physiotherapy, Curtin University, Perth, AUSTRALIA; 3Baker IDI Heart and Diabetes Institute, Melbourne, AUSTRALIA; 4Mary MacKillop Institute of Health Research, Australian Catholic University, Melbourne, AUSTRALIA; 5Institute for Physical Activity and Nutrition, Deakin University, Burwood, AUSTRALIA; 6Department of Medicine, Alfred Hospital, Monash University, Melbourne, AUSTRALIA; 7School of Public Health and Preventive Medicine, Monash University, Melbourne, AUSTRALIA; 8School of Sport Science, Exercise and Health, The University of Western Australia, Perth, AUSTRALIA; 9Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, AUSTRALIA; 10Swinburne University of Technology, Melbourne, AUSTRALIA; 11Centre for Health Services Research, The University of Queensland, Brisbane, AUSTRALIA; and 12Mater Research Institute, The University of Queensland, South Brisbane, AUSTRALIA.
authors.forename: Natasha
authors.initials: N
authors.lastname: Reid
authors.forename: Genevieve N
authors.initials: GN
authors.lastname: Healy
authors.forename: Robin M
authors.initials: RM
authors.lastname: Daly
authors.forename: Peter
authors.initials: P
authors.lastname: Baker
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Eakin
authors.forename: David W
authors.initials: DW
authors.lastname: Dunstan
authors.forename: Neville
authors.initials: N
authors.lastname: Owen
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gardiner
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007717:Knee / Q000502:physiology; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D057185:Sedentary Behavior; D013690:Television; D013997:Time Factors