title: Sedentary time and cardio-metabolic biomarkers in US adults: NHANES 2003-06.
abstract: OBJECTIVE
  Prolonged sedentary time is ubiquitous in developed economies and is associated with an adverse cardio-metabolic risk profile and premature mortality. This study examined the associations of objectively assessed sedentary time and breaks (interruptions) in sedentary time with continuous cardio-metabolic and inflammatory risk biomarkers, and whether these associations varied by sex, age, and/or race/ethnicity.
  
  
  RESULTS
  Cross-sectional analyses with 4757 participants (≥ 20 years) from the 2003/04 and 2005/06 US National Health and Nutrition Examination Survey (NHANES). An Actigraph accelerometer was used to derive sedentary time [< 100 counts per minute (cpm)] and breaks in sedentary time. Independent of potential confounders, including moderate-to-vigorous exercise, detrimental linear associations (P for trends < 0.05) of sedentary time with waist circumference, HDL-cholesterol, C-reactive protein, triglycerides, insulin, HOMA-%B, and HOMA-%S were observed. Independent of potential confounders and sedentary time, breaks were beneficially associated with waist circumference and C-reactive protein (P for trends <0.05). There was limited evidence of meaningful differences in associations with biomarkers by age, sex, or race/ethnicity. Notable exceptions were sex-differences in the associations of sedentary time and breaks with HDL-cholesterol, and race/ethnicity differences in the association of sedentary time with waist circumference with associations detrimental in non-Hispanic whites, null in Mexican Americans, and beneficial in non-Hispanic blacks.
  
  
  CONCLUSIONS
  These are the first population-representative findings on the deleterious associations of prolonged sedentary time with cardio-metabolic and inflammatory biomarkers. The findings suggest that clinical communications and preventive health messages on reducing and breaking up sedentary time may be beneficial for cardiovascular disease risk.
authors.affiliation: Cancer Prevention Research Centre, School of Population Health, The University of Queensland, Herston, QLD 4006, Australia. g.healy@uq.edu.au
authors.forename: Genevieve N
authors.initials: GN
authors.lastname: Healy
authors.forename: Charles E
authors.initials: CE
authors.lastname: Matthews
authors.forename: David W
authors.initials: DW
authors.lastname: Dunstan
authors.forename: Elisabeth A H
authors.initials: EA
authors.lastname: Winkler
authors.forename: Neville
authors.initials: N
authors.lastname: Owen
mesh_terms: D000054:Acceleration; D000328:Adult; D017677:Age Distribution; D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000208:ethnology / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D057185:Sedentary Behavior; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D055105:Waist Circumference
chemical_list: D015415:Biomarkers