title: Predicting sleep-disordered breathing in patients with cystic fibrosis.
abstract: OBJECTIVE
  To examine predictors of sleep-disordered breathing in patients with cystic fibrosis (CF) and moderate-to-severe lung disease using a comprehensive evaluation of both sleep and daytime function.
  
  
  METHODS
  Cross-sectional analysis of sleep studies, lung function, respiratory muscle strength, and evening and morning arterial blood gas measurements in patients with stable CF. A questionnaire addressing sleep quality was administered. Forward stepwise regression analysis was used to identify the parameters that best predict sleep-related desaturation, hypercapnia, and respiratory disturbance.
  
  
  METHODS
  Sleep investigation unit and lung function laboratory.
  
  
  METHODS
  Thirty-two patients with CF and FEV(1) < 65% predicted, in stable clinical condition. Patients were aged 27 +/- 8 years (mean +/- 1 SD) with FEV(1) of 36 +/- 10% predicted, evening PaO(2) of 68 +/- 8 mm Hg, and PaCO(2) of 43 +/- 5 mm Hg.
  
  
  RESULTS
  Evening PaO(2) (p < 0.0001) and morning PaCO(2) (p < 0.01) were predictive of the average minimum oxyhemoglobin saturation per 30-s epoch of sleep (r(2) = 0.74; p < 0.0001). Evening PaO(2) (p < 0.001) was predictive of the rise in transcutaneous carbon dioxide (TcCO(2)) seen from non-rapid eye movement (NREM) to rapid eye movement (REM) sleep (r(2) = 0.37; p < 0.001). In addition, there was some relationship between expiratory respiratory muscle strength and the REM respiratory disturbance index (r(2) = 0.22; p < 0.01).
  
  
  CONCLUSIONS
  Evening PaO(2) was found to contribute significantly to the ability to predict both sleep-related desaturation and the rise in TcCO(2) from NREM sleep to REM sleep in this subgroup of patients with CF.
authors.affiliation: Department of Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, Sydney.
authors.forename: M A
authors.initials: MA
authors.lastname: Milross
authors.forename: A J
authors.initials: AJ
authors.lastname: Piper
authors.forename: M
authors.initials: M
authors.lastname: Norman
authors.forename: G N
authors.initials: GN
authors.lastname: Willson
authors.forename: R R
authors.initials: RR
authors.lastname: Grunstein
authors.forename: C E
authors.initials: CE
authors.lastname: Sullivan
authors.forename: P T
authors.initials: PT
authors.lastname: Bye
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D002940:Circadian Rhythm / Q000502:physiology; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology
chemical_list: D010108:Oxyhemoglobins