title: [The severity of obstructive sleep apnea and hypopnea syndrome in different sleep stage].
abstract: OBJECTIVE
  This study aimed to inspect the hypothesis that obstructive sleep apnea and hypopnea syndrome (OSAHS) was commonly worse in REM sleep than in NREM sleep stage, and also to analyze the relevance with the risk factors of OSAHS.
  
  
  METHODS
  One hundred eighteen patients diagnosed as OSAHS by overnight polysomnography (PSG) were studied retrospectively. The severity of OSAHS in REM versus NREM sleep was compared. Then the patients were divided into two groups: AHI(REM) > or = AHI(NREM) group, and AHI(REM) < AHI(NREM) group, and the two groups were compared in age, sex, BMI, AHI, AHI supine, oxygen desaturation and duration of apnea.
  
  
  RESULTS
  There was no significant difference between AHI(REM) and AHI(NREM). AHI(REM)/AHI(NREM) was 1.0 +/- 0.5. A higher AHI NREM than AHI REM group was found in 55.9% of the 118 patients with OSAHS. There were no differences between the clinical and PSG founding of two groups.
  
  
  CONCLUSIONS
  The severity of OSAHS is not greatly influenced by sleep stage.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Affiliated Hospital to Beihua University, Jilin, 132011, China. zxs781215@sohu.com
authors.forename: Xuesong
authors.initials: X
authors.lastname: Zheng
authors.forename: Nongsheng
authors.initials: N
authors.lastname: Hou
authors.forename: Rui
authors.initials: R
authors.lastname: Hao
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012189:Retrospective Studies; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D012894:Sleep Stages; D012895:Sleep, REM; D055815:Young Adult