title: Sleep pressure score: a new index of sleep disruption in snoring children.
abstract: OBJECTIVE
  Excessive daytime sleepiness (EDS), as measured by objective criteria, is infrequent in snoring children despite a high prevalence of EDS-related behavioral manifestations. We hypothesized that sleep architecture and arousal indexes may be altered relative to the severity of sleep-disordered breathing (SDB).
  
  
  METHODS
  Retrospective and prospective study.
  
  
  METHODS
  Questionnaires were distributed through sleep clinic or school program; polysomnograms were performed at Kosair Children's Hospital in Louisville, Kentucky.
  
  
  METHODS
  To examine this issue, 182 children with SDB, 163 children with primary snoring, and 214 control children with a mean age of 6.9 +/- 2.6 years underwent polysomnographic evaluation in the laboratory.
  
  
  RESULTS
  Significant increases in slow-wave sleep (percentage of total sleep time) and decreases in rapid eye movement sleep (percentage of total sleep time) occurred in the SDB group (P < .0001). Spontaneous and respiratory arousal indexes and the apnea-hypopnea index (AHI) displayed negative and positive correlations, respectively, suggesting reciprocal interactions. Based on these observations, a sleep pressure score (SPS) was derived as a surrogate numeric measure for disrupted sleep homeostasis. The SPS exhibited linear increases relative to AHI, reaching a plateau at an AHI of 30 to 40 per hour of total sleep time. Furthermore, SPS values were significantly higher among African American and obese children (P < .0001).
  
  
  CONCLUSIONS
  Sleep architecture is not preserved in children with SDB. An algorithm allowing for calculation of sleep propensity and disturbed sleep homeostasis in children who snore is proposed and may be of practical value in the assessment of sleepiness.
authors.affiliation: Kosair Children's Hospital Research Institute, Division of Pediatric Sleep Medicine, Department of Pediatrics, University of Louisville, Kentucky 40202, USA.
authors.forename: Riva
authors.initials: R
authors.lastname: Tauman
authors.forename: Louise M
authors.initials: LM
authors.lastname: O'Brien
authors.forename: Cheryl R
authors.initials: CR
authors.lastname: Holbrook
authors.forename: David
authors.initials: D
authors.lastname: Gozal
mesh_terms: D015992:Body Mass Index; D002648:Child; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D015995:Prevalence; D011446:Prospective Studies; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000453:epidemiology; D012894:Sleep Stages / Q000502:physiology; D012913:Snoring / Q000175:diagnosis* / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014851:Wakefulness / Q000502:physiology