title: Sleep findings and predictors of sleep desaturation in adult cystic fibrosis patients.
abstract: OBJECTIVE
  Questions remain about the polysomnographic findings and the predictors for sleep desaturation in cystic fibrosis (CF) patients. Our study aimed to evaluate sleep parameters in a sample of adult CF patients comparing them with healthy controls and to determine the best predictors of sleep desaturation in CF patients with awake resting peripheral oxygen saturation (SpO(2)) ≥90%.
  
  
  METHODS
  In a cross-sectional study, with data collected prospectively, 51 clinically stable adult CF patients (mean age 25.1 ± 6.7 years) and 25 age-matched controls underwent an overnight polysomnography and answered sleep questionnaires. CF patients had their pulmonary function, 6-min walk test, and echocardiography assessed.
  
  
  RESULTS
  CF patients and control subjects had similar sleep architecture. However, CF patients had impaired subjective sleep quality and a higher arousal index than controls. The apnea-hypopnea index was similar in both groups, and only two CF patients (3.9%) fulfilled the criteria for obstructive sleep apnea syndrome. Sleep desaturation was more common in CF patients (29.4% vs 0%; p < 0.001). In a logistic regression model, we observed that awake resting SpO(2) was the single best variable associated with sleep desaturation in CF population (p < 0.001). The awake SpO(2) <94% had a sensitivity, specificity, positive and negative predictive value for sleep desaturation of, respectively, 93.3%, 100%, 100%, and 97.3%.
  
  
  CONCLUSIONS
  CF patients had a worse subjective sleep quality and small changes in sleep architecture. In nonhypoxic, adult CF patients, sleep desaturation is common, is not associated with obstructive sleep events, and can be accurately predicted by awake resting SpO(2) <94%.
authors.affiliation: Division of Pulmonology, Hospital de Clinicas de Porto Alegre (HCPA) and Postgraduate Program in Pulmonology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. perinpoa@terra.com.br
authors.forename: Christiano
authors.initials: C
authors.lastname: Perin
authors.forename: Simone C
authors.initials: SC
authors.lastname: Fagondes
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Casarotto
authors.forename: Antônio F F
authors.initials: AF
authors.lastname: Pinotti
authors.forename: Sérgio S
authors.initials: SS
authors.lastname: Menna Barreto
authors.forename: Paulo de Tarso R
authors.initials: Pde T
authors.lastname: Dalcin
mesh_terms: D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000453:epidemiology; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood*; D017286:Polysomnography; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D010100:Oxygen