title: Cut-off values for step count and TV viewing time as discriminators of hyperglycaemia in Brazilian children and adolescents.
abstract: BACKGROUND
  The use of step count and TV viewing time to discriminate youngsters with hyperglycaemia is still a matter of debate.
  
  
  OBJECTIVE
  To establish cut-off values for step count and TV viewing time in children and adolescents using glycaemia as the reference criterion.
  
  
  METHODS
  A cross-sectional study was conducted on 1044 schoolchildren aged 6-18 years from Northeastern Brazil. Daily step counts were assessed with a pedometer over 1 week and TV viewing time by self-report.
  
  
  RESULTS
  The area under the curve (AUC) ranged from 0.52-0.61 for step count and from 0.49-0.65 for TV viewing time. The daily step count with the highest discriminatory power for hyperglycaemia was 13 884 (sensitivity = 77.8; specificity = 51.8) for male children and 12 371 (sensitivity = 55.6; specificity = 55.5) and 11 292 (sensitivity = 57.7; specificity = 48.6) for female children and adolescents respectively. The cut-off for TV viewing time with the highest discriminatory capacity for hyperglycaemia was 3 hours/day (sensitivity = 57.7-77.8; specificity = 48.6-53.2).
  
  
  CONCLUSIONS
  This study represents the first step for the development of criteria based on cardiometabolic risk factors for step count and TV viewing time in youngsters. However, the present cut-off values have limited practical application because of their poor accuracy and low sensitivity and specificity.
authors.affiliation: a Physical Education Course, Federal University of Reconcavo of Bahia , Amargosa , Bahia , Brazil .|b Faculty of Medicine , Post-Graduate Program in Medicine and Health, Federal University of Bahia , Salvador , Bahia , Brazil , and.|c Research Centre in Physical Activity Health and Leisure, Faculty of Sport Sciences, University of Porto , Porto , Portugal.
authors.forename: Alex Pinheiro
authors.initials: AP
authors.lastname: Gordia
authors.affiliation: a Physical Education Course, Federal University of Reconcavo of Bahia , Amargosa , Bahia , Brazil .|b Faculty of Medicine , Post-Graduate Program in Medicine and Health, Federal University of Bahia , Salvador , Bahia , Brazil , and.|c Research Centre in Physical Activity Health and Leisure, Faculty of Sport Sciences, University of Porto , Porto , Portugal.
authors.forename: Teresa Maria Bianchini de
authors.initials: TM
authors.lastname: Quadros
authors.affiliation: b Faculty of Medicine , Post-Graduate Program in Medicine and Health, Federal University of Bahia , Salvador , Bahia , Brazil , and.
authors.forename: Luciana Rodrigues
authors.initials: LR
authors.lastname: Silva
authors.affiliation: c Research Centre in Physical Activity Health and Leisure, Faculty of Sport Sciences, University of Porto , Porto , Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Mota
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D001519:Behavior; D001786:Blood Glucose / Q000378:metabolism; D001938:Brazil; D002648:Child; D016001:Confidence Intervals; D003710:Demography; D015444:Exercise; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000503:physiopathology*; D008297:Male; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013690:Television; D013997:Time Factors
chemical_list: D001786:Blood Glucose
keywords: Motor activity; diabetes mellitus; hyperglycaemia; pediatrics; sedentary lifestyle