title: Sitting time and health outcomes among Mexican origin adults: obesity as a mediator.
abstract: BACKGROUND
  Sitting time and sedentary behaviors have been associated with adverse health outcomes including obesity, diabetes and cardiovascular disease (CVD) within non- Hispanic White populations. Similar associations have not been described within Hispanic populations despite their high CVD risk profile. This study aimed to assess the association between sitting time and obesity, self-reported diagnosed diabetes, hypertension and high cholesterol among a large cohort (N=11,268) of Mexican origin adults and to assess whether obesity mediated these associations.
  
  
  METHODS
  Using a cross-sectional design, data collected between 2004 and 2010 were analyzed in late 2010. Regression analyses evaluated associations between self-reported daily sitting hours and disease outcomes, controlling for demographics, employment status, family disease history, and light, moderate and strenuous physical activity.
  
  
  RESULTS
  Participants were mostly female (81.1%) Mexican origin adults. Sitting time was associated with increased odds of being obese, having diabetes and having hypertension, but not high cholesterol. Adjusted odds ratios of participants who reported sitting > 4 hours/day compared to those sitting 1-2 hours/day were for obesity OR=1.55 (95% CI 1.39, 1.73), p<.001, for diabetes OR=1.29 (95% CI, 1.09, 1.52), p=.003, for hypertension OR=1.17 (95% CI, 1.01, 1.37), p=.041. Associations controlled for physical activity and employment status. Effects on hypertension and diabetes were mediated by obesity.
  
  
  CONCLUSIONS
  Sitting time was significantly associated with detrimental health outcomes, independent of physical activity. Obesity mediated these relationships for diabetes and hypertension. Future research should assess whether interventions addressing sitting time are feasible and effective among Mexican origin populations.
authors.affiliation: Department of Physical Therapy and Athletic Training, Northern Arizona University, 208 E Pine Knoll Dr. Bldg. 66, Rm. 112, PO Box 15105, Flagstaff 86011, AZ, USA. hendrik.deheer@nau.edu
authors.forename: Hendrik D
authors.initials: HD
authors.lastname: de Heer
authors.forename: Anna V
authors.initials: AV
authors.lastname: Wilkinson
authors.forename: Larkin L
authors.initials: LL
authors.lastname: Strong
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Bondy
authors.forename: Laura M
authors.initials: LM
authors.lastname: Koehly
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000208:ethnology* / Q000209:etiology; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000208:ethnology* / Q000209:etiology; D006973:Hypertension / Q000208:ethnology* / Q000209:etiology; D008297:Male; D017058:Mexican Americans / Q000706:statistics & numerical data*; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000208:ethnology*; D011187:Posture; D036301:Qualitative Research; D012307:Risk Factors; D057185:Sedentary Behavior / Q000208:ethnology*; D057566:Self Report; D013997:Time Factors