title: Factors influencing the response of psychological symptoms to continuous positive airway pressure therapy.
abstract: OBJECTIVE
  To examine whether in obstructive sleep apnea (OSA) patients the degree of sleepiness, slow-wave sleep (SWS) loss, and hypoxia influence the response of psychological symptoms to continuous positive airway pressure (CPAP) therapy.
  
  
  METHODS
  A prospectively planned cohort was assessed. Participants underwent full overnight polysomnography. All answered the Symptom Checklist-90-Revised (SCL-90) and the Epworth sleepiness scale (ESS). Only cases with an apnea-hypopnea index ≤60 events/h were 24 invited to participate. In an interview by telephone, after a follow-up period between 2 months and 1 year, patients informed whether they were in treatment with CPAP or remained voluntarily untreated. Subjects who accepted to participate answered for the second time the SCL-90 and the ESS. The baseline variables of interest were: (a) score of the ESS, (b) duration of SWS, and (c) time with arterial oxygen saturation below 90%. The outcomes were the change in SCL-90 scores in all dimensions and indices of the questionnaire.
  
  
  RESULTS
  A number of 73 patients, mostly men, were included. In uncontrolled analyses, CPAP-treated patients showed significant improvement at follow-up in 10 of the 13 SCL-90 scores. Comparing with the control group, only six scores were improved. Baseline sleepiness was the best predictor of SCL-90 improvement after CPAP treatment in the univariate analyses, and the only significant predictor of improvement in a multivariate regression model.
  
  
  CONCLUSIONS
  Sleepiness may supersede other factors that influence psychological improvement in CPAP-treated patients with severe OSA.
authors.affiliation: Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil, alicia.ufrgs@gmail.com.
authors.forename: Alicia
authors.initials: A
authors.lastname: Carissimi
authors.forename: Denis
authors.initials: D
authors.lastname: Martinez
authors.forename: Lenise J
authors.initials: LJ
authors.lastname: Kim
authors.forename: Cintia Z
authors.initials: CZ
authors.lastname: Fiori
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure / Q000523:psychology*; D006970:Disorders of Excessive Somnolence / Q000523:psychology* / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000523:psychology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000523:psychology* / Q000628:therapy*; D012892:Sleep Deprivation / Q000523:psychology / Q000628:therapy; D011795:Surveys and Questionnaires