title: Occurrence and duration of various operational definitions of sedentary bouts and cross-sectional associations with cardiometabolic health indicators: the ENERGY-project.
abstract: OBJECTIVE
  This study examined the occurrence and duration of sedentary bouts and explored the cross-sectional association with health indicators in children applying various operational definitions of sedentary bouts.
  
  
  METHODS
  Accelerometer data of 647 children (10-13 years old) were collected in five European countries. We analyzed sedentary time (<100 cpm) accumulated in bouts of at least 5, 10, 20 or 30 min based on four operational definitions, allowing 0, 30 or 60s ≥100 cpm within bouts. Health indicators included anthropometrics (i.e. waist circumference and body mass index (BMI)) and in a subsample from two European countries (n=112) fasting capillary blood levels of glucose, C-peptide, high-density- and low-density cholesterol, and triglycerides. Data collection took place from March to July 2010. Associations were adjusted for age, gender, moderate-to-vigorous physical activity, total wear time and country.
  
  
  RESULTS
  Occurrence of sedentary bouts varied largely between the various definitions. Children spent most of their sedentary time in bouts of ≥5 min while bouts of ≥20 min were rare. Linear regression analysis revealed few significant associations of sedentary time accumulated in bouts of ≥5-30 min with health indicators. Moreover, we found that more associations became significant when allowing no tolerance time within sedentary bouts.
  
  
  CONCLUSIONS
  Despite a few significant associations, we found no convincing evidence for an association between sedentary time accumulated in bouts and health indicators in 10-13 year old children.
authors.affiliation: VU University Medical Center, EMGO Institute for Health and Care Research, Department of Public and Occupational Health, Amsterdam, The Netherlands. Electronic address: t.altenburg@vumc.nl.
authors.forename: T M
authors.initials: TM
authors.lastname: Altenburg
authors.affiliation: Science Support, Utrecht, The Netherlands. Electronic address: markdeniet@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: de Niet
authors.affiliation: Ghent University, Department of Movement and Sport Sciences, Ghent, Belgium. Electronic address: Maite.Verloigne@Ugent.be.
authors.forename: M
authors.initials: M
authors.lastname: Verloigne
authors.affiliation: Ghent University, Department of Movement and Sport Sciences, Ghent, Belgium. Electronic address: Ilse.Debourdeaudhuij@UGent.be.
authors.forename: I
authors.initials: I
authors.lastname: De Bourdeaudhuij
authors.affiliation: Department of Nutrition-Dietetics, School of Health Science and Education, Harokopio University Athens, Athens, Greece. Electronic address: oandrou@hua.gr.
authors.forename: O
authors.initials: O
authors.lastname: Androutsos
authors.affiliation: Department of Nutrition-Dietetics, School of Health Science and Education, Harokopio University Athens, Athens, Greece. Electronic address: manios@hua.gr.
authors.forename: Y
authors.initials: Y
authors.lastname: Manios
authors.affiliation: Department of Paediatrics, University of Pécs, Pécs, Hungary. Electronic address: kovacs.eva.katalin@pte.hu.
authors.forename: E
authors.initials: E
authors.lastname: Kovacs
authors.affiliation: Department of Epidemiology and Public Health, Swiss TPH, Basel, Switzerland; University of Basel, Basel, Switzerland. Electronic address: Bettina.Bringolf@unibas.ch.
authors.forename: B
authors.initials: B
authors.lastname: Bringolf-Isler
authors.affiliation: VU University Medical Center, EMGO Institute for Health and Care Research, Department of Epidemiology & Biostatistics, Amsterdam, The Netherlands. Electronic address: j.brug@vumc.nl.
authors.forename: J
authors.initials: J
authors.lastname: Brug
authors.affiliation: VU University Medical Center, EMGO Institute for Health and Care Research, Department of Public and Occupational Health, Amsterdam, The Netherlands. Electronic address: m.chinapaw@vumc.nl.
authors.forename: M J M
authors.initials: MJ
authors.lastname: Chinapaw
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D000886:Anthropometry; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D000067576:Child Health; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D016014:Linear Models; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D050177:Overweight / Q000453:epidemiology; D057185:Sedentary Behavior; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
chemical_list: D002096:C-Peptide; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002784:Cholesterol
keywords: Body composition; Fasting blood; Sedentary bout; Sedentary time; Youth