title: Patterns of Sedentary Behavior in US Middle-Age and Older Adults: The REGARDS Study.
abstract: OBJECTIVE
  The purposes of this study were to examine patterns of objectively measured sedentary behavior in a national cohort of US middle-age and older adults and to determine factors that influence prolonged sedentary behavior.
  
  
  METHODS
  We studied 8096 participants from the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study, a population-based study of black and white adults 45 yr or older. Seven-day accelerometry was conducted. Prolonged sedentary behavior was defined as accumulating 50% or more of total sedentary time in bouts of 30 min or greater.
  
  
  RESULTS
  The number of sedentary bouts greater than or equal to 20, 30, 60, and 90 min were 8.8 ± 2.3, 5.5 ± 1.9, 1.9 ± 1.1, and 0.8 ± 0.7 bouts per day, respectively. Sedentary bouts greater than or equal to 20, 30, 60, and 90 min accounted for 60.0% ± 13.9%, 48.0% ± 15.5%, 26.0% ± 15.4%, and 14.2% ± 12.9% of total sedentary time, respectively. Several factors were associated with prolonged sedentary behavior in multivariate-adjusted models (odds ratio [95% confidence interval]): older age (65-74 yr: 1.99 [1.55-2.57]; 75 yr or older: 4.68 [3.61-6.07] vs 45-54 yr), male sex (1.41 [1.28-1.56] vs female), residence in nonstroke belt/buckle region of the United States (stroke belt: 0.87 [0.77-0.98]; stroke buckle: 0.86 [0.77-0.95] vs non-belt/buckle), body mass index (BMI) (overweight: 1.33 [1.18-1.51]; obese: 2.15 [1.89-2.44] vs normal weight), winter (1.18 [1.03-1.35] vs summer), and low amounts of moderate-to-vigorous physical activity (MVPA) [0 min·wk: 2.00 [1.66-2.40] vs ≥150 min·wk).
  
  
  CONCLUSIONS
  In this sample of US middle-age and older adults, a large proportion of total sedentary time was accumulated in prolonged, uninterrupted bouts of sedentary behavior as almost one-half was accumulated in sedentary bouts greater than or equal to 30 min. Several sociodemographic (age, sex, and BMI), behavioral (MVPA), environmental (region), and seasonal factors are associated with patterns of prolonged sedentary behavior.
authors.affiliation: 1Center for Behavioral Cardiovascular Health, Department of Medicine, Columbia University Medical Center, New York, NY; 2Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, AL; 3Prevention Research Center, Arnold School of Public Health, University of South Carolina, Columbia, SC; 4Institute for Social Research and School of Kinesiology, University of Michigan, Ann Arbor, MI; 5Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC; 6Departments of Exercise Science and Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC; and 7School of Nutrition and Health Promotion, Arizona State University, Phoenix, AZ.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Diaz
authors.forename: Virginia J
authors.initials: VJ
authors.lastname: Howard
authors.forename: Brent
authors.initials: B
authors.lastname: Hutto
authors.forename: Natalie
authors.initials: N
authors.lastname: Colabianchi
authors.forename: John E
authors.initials: JE
authors.lastname: Vena
authors.forename: Steven N
authors.initials: SN
authors.lastname: Blair
authors.forename: Steven P
authors.initials: SP
authors.lastname: Hooker
mesh_terms: D061725:Accelerometry; D001741:Black or African American; D000368:Aged; D015992:Body Mass Index; D015444:Exercise; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012621:Seasons; D057185:Sedentary Behavior; D013997:Time Factors; D014481:United States; D044465:White People