title: [Relationship between excessive daytime sleepiness and oxygen saturation in obstructive sleep apnea-hypopnea syndrome].
abstract: OBJECTIVE
  To investigate polysomnographic determinants of excessive daytime sleepiness (EDS) and potential relationship in Chinese patients with obstructive sleep apnea-hypopnea syndrome (OSAS).
  
  
  METHODS
  A total of 410 patients with obstructive sleep apnea-hypopnea syndrome were analyzed retrospectively who were obtained in Sleep medicine center of West China hospital from January to April in 2010. All of the patients with an apnea-hypopnea index (AHI) greater than 5 h(-1) were evaluated using the Epworth Sleepiness Scale (ESS) and sleep disorders questionnaire. The patients who ESS score was more than 10 were defined as EDS; otherwise, the other was considered to without EDS.
  
  
  RESULTS
  A total of 176 patients with EDS (ESS: 15 ± 3) and 234 without EDS (ESS: 6 ± 3) were studied. Patients with EDS were slightly higher BMI (28 ± 4 vs 26 ± 4) and shorter REM sleep latency (99 ± 65 vs 125 ± 81) than patients without EDS. Furthermore, there were significant difference in awake SaO2, AHI, minimum SaO2, oxygen desaturation index and arousal index between EDS group were No-EDS group (P < 0.001). There was a significant difference in waking SaO2 of severe OSAS between both groups.
  
  
  CONCLUSIONS
  Long-term chronic hypoxia already exists in severe OSAS patients with prominent sleepiness. Waking SaO2 may play a role as a predictor in evaluation and diagnosis in patients with OSAS.
authors.affiliation: Department of Sleep Medicine, West China Hospital of Sichuan University, Chengdu 610041, China.
authors.forename: Ze-Qi
authors.initials: ZQ
authors.lastname: Zhong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tao
authors.forename: Zong-Ping
authors.initials: ZP
authors.lastname: Zhang
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Zhou
authors.forename: Fei
authors.initials: F
authors.lastname: Lei
authors.forename: Li-Na
authors.initials: LN
authors.lastname: DU
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Tang
mesh_terms: D000328:Adult; D006970:Disorders of Excessive Somnolence / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D012894:Sleep Stages; D011795:Surveys and Questionnaires; D014851:Wakefulness