title: Neck circumference percentile: A screening tool for pediatric obstructive sleep apnea.
abstract: BACKGROUND
  Large neck circumference (NC) is associated with obstructive sleep apnea (OSA) in adults, especially males. Since NC changes with age and sex, a lack of reference ranges makes neck size difficult to assess as a screening tool in children.
  
  
  METHODS
  Using a population-based dataset of 1,913 children, we developed reference ranges for NC by age and sex for children aged 6-17 years. In this study, we collected NC data on 245 children aged 6-17 years presenting to the Children's Hospital of Eastern Ontario for polysomnography. The association between NC>the 95th percentile and OSA (total apnea-hypopnea-index>5 events/hr and/or obstructive-apnea-index ≥ 1 event/hr) was explored. Thresholds of BMI percentile and waist circumference were also examined.
  
  
  RESULTS
  Individuals with NC>95th percentile for age and sex had increased risk of OSA (relative risk 1.7 [95% CI 1.0-3.0], P=0.04), compared to those with NC ≤ 95th percentile. BMI ≥ 95th percentile gave similar results (relative risk 1.8 [95% CI 1.1-2.9], P=0.02). When examined by sex, the association was significant in males ≥ 12 years (relative risk 3.3 [95% CI 1.0-10.4], P=0.04), but not females (P=0.63). Neither BMI  ≥ 95th percentile nor waist circumference>95th percentile was significant.
  
  
  CONCLUSIONS
  Children and youth with NC>95th percentile for age and sex have significantly increased risk of OSA. This effect is significant in males ≥ 12 years, whereas BMI is not. NC percentile may be an additional screening tool for OSA in children and youth.
authors.affiliation: Division of Respirology, Department of Pediatrics, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada; Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Sherri
authors.initials: S
authors.lastname: Katz
authors.forename: Kimmo
authors.initials: K
authors.lastname: Murto
authors.forename: Nicholas
authors.initials: N
authors.lastname: Barrowman
authors.forename: Janine
authors.initials: J
authors.lastname: Clarke
authors.forename: Lynda
authors.initials: L
authors.lastname: Hoey
authors.forename: Franco
authors.initials: F
authors.lastname: Momoli
authors.forename: Robert
authors.initials: R
authors.lastname: Laberge
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Vaccani
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009333:Neck / Q000033:anatomy & histology*; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*; D055105:Waist Circumference
keywords: neck circumference; obstructive sleep apnea; pediatric; percentiles; predictor