title: Physical activity, sedentary behaviors and the incidence of type 2 diabetes mellitus: the Multi-Ethnic Study of Atherosclerosis (MESA).
abstract: BACKGROUND
  The association between physical activity (PA), sedentary behavior, and incident diabetes has been assessed in whites but is less well investigated in multiethnic populations.
  
  
  OBJECTIVE
  To assess the association between PA, sedentary behavior, and incident diabetes in the Multi-Ethnic Study of Atherosclerosis.
  
  
  METHODS
  Incident diabetes was assessed among adults without prevalent baseline diabetes (2000-2002) at 5 in-person examinations between 2002 and 2012. Baseline PA (moderate, vigorous, and exercise-specific; metabolic equivalents of task-hours/week) and sedentary behaviors (television watching, reading; hours/day) were assessed by questionnaire. HRs were estimated using Cox proportional hazard models.
  
  
  RESULTS
  Among 5829 adults (mean age 61.8 years, 54% female, 42% white, 12% Chinese-American, 26% African-American, 21% Hispanic-American), there were 655 incident diabetes cases (median follow-up 11.1 years). After adjustment, diabetes risk was lower in those with brisk or striding compared with none or casual walking pace (HR 0.67; 95% CI 0.54 to 0.84), higher levels of exercise PA (HR for highest vs lowest quartile 0.79; 95% CI 0.63 to 0.98), and any compared with no vigorous PA (HR 0.79; 95% CI 0.66 to 0.95). Race/ethnicity influenced the association of walking pace, exercise PA, and any vigorous PA on diabetes risk, which was only significant among whites. Total leisure sedentary behaviors (HR for highest vs lowest quartile 1.65; 95% CI 1.26 to 2.14) and television watching (HR for highest vs lowest quartile 2.68; 95% CI 1.38 to 5.21) were significantly associated with diabetes risk in multiethnic analyses and were influenced by race/ethnicity.
  
  
  CONCLUSIONS
  These results confirm the importance of PA and sedentary behavior on diabetes risk in a multiethnic population and demonstrate potential variations across race/ethnic groups.
authors.affiliation: Johns Hopkins University School of Medicine , Baltimore, Maryland , USA.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Joseph
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, Georgia, USA; Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.
authors.forename: Justin B
authors.identifier: 0000-0002-8460-1617
authors.initials: JB
authors.lastname: Echouffo-Tcheugui
authors.affiliation: Johns Hopkins University School of Medicine , Baltimore, Maryland , USA.
authors.forename: Sherita H
authors.initials: SH
authors.lastname: Golden
authors.affiliation: Division of Public Health Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA; Department of Biostatistical Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.
authors.forename: Haiying
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Pathology and Laboratory Medicine , University of Vermont College of Medicine , Burlington, Vermont , USA.
authors.forename: Nancy Swords
authors.initials: NS
authors.lastname: Jenny
authors.affiliation: Department of Preventive Medicine , Feinberg School of Medicine, Northwestern University , Chicago, Illinois , USA.
authors.forename: Mercedes R
authors.initials: MR
authors.lastname: Carnethon
authors.affiliation: Division of Epidemiology and Community Health , School of Public Health, University of Minnesota , Minneapolis, Minnesota , USA.
authors.forename: David
authors.initials: D
authors.lastname: Jacobs
authors.affiliation: Division of Public Health Sciences , Wake Forest University Health Sciences , Winston-Salem, North Carolina , USA.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Burke
authors.affiliation: Johns Hopkins University School of Medicine , Baltimore, Maryland , USA.
authors.forename: Dhananjay
authors.initials: D
authors.lastname: Vaidya
authors.affiliation: Johns Hopkins University School of Medicine , Baltimore, Maryland , USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Ouyang
authors.affiliation: Division of Public Health Sciences , Wake Forest University Health Sciences , Winston-Salem, North Carolina , USA.
authors.forename: Alain G
authors.initials: AG
authors.lastname: Bertoni
keywords: Physical Activity Epidemiology; Racial Differences; Sedentary Behaviors; Type 2 Diabetes