title: Respiratory sleep disturbance in children and adolescents with cystic fibrosis.
abstract: Sleep disturbance has been described in cystic fibrosis (CF) patients as relevant to clinical and lung function predictive factors helping to improve the diagnosis and early intervention. Related paediatric studies are scarce.
  
  
  OBJECTIVE
  To describe respiratory sleep disturbance (RSD) and its association with spirometric indices in a population of CF children. A second aim was to determine if spirometric indices and wake-time SpO2 are predictors of sleep disturbance.
  
  
  METHODS
  A cross-sectional study involving 33CF paediatric patients. All participants underwent in-lab polysomnography (PSG), pulse oximetry and spirometry. A standardized sleep questionnaire was completed for each patient. Two subgroups were considered: I - Normal (FEV1>-1.64 z-score); II - Obstructed (FEV1≤-1.64 z-score).
  
  
  RESULTS
  Participant's median age was 12 (6-18) years, 16 (48.5%) were male. Twenty-nine patients (87.9%) presented sleep complaints. Sleep efficiency was reduced; sleep latency and waking after sleep onset (WASO) increased. N1 increased, N2, N3, REM and awakenings were normal. The apnoea-hypopnoea index was 0.6/h (sd 0.9); respiratory disturbance index (RDI) was 6.6/h (sd 5.2). Mean awaking (97% (sd 1.1)) and sleep SpO2 (95% (sd 2.7)) were normal; mean nocturnal oximetry desaturation index was 2.36/h; minimal nocturnal SpO2 was 89% (sd 4.1). We found associations between mean nocturnal SPO2 and mean values of FEV1 (r=0.528; p=0.002) and FEF25-75 (r=0.426; p=0.013). There were significant differences in nocturnal SpO2 between normal and obstructed patients (p<0.000). PSG data correlated with the questionnaire answers for night awakenings and WASO (p=0.985) and difficult breathing during sleep and RDI (p=0.722). This study points to most CF children having sleep complaints, and highlights the correlation between subjective assessment of sleep and PSG and spirometric results. Awake-time SpO2 and spirometric values are possible risk predictors for nocturnal desaturation.
authors.affiliation: Pediatric Lung Function and Sleep Laboratory, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: anammsilva@gmail.com.
authors.forename: A M
authors.initials: AM
authors.lastname: Silva
authors.affiliation: Pediatric Lung Function and Sleep Laboratory, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: andreiadescalco@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Descalço
authors.affiliation: Pediatric Lung Function and Sleep Laboratory, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: marisasalgueiro@hotmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Salgueiro
authors.affiliation: Respiratory Unit, Department of Pediatrics, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: mluisafpereira@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Pereira
authors.affiliation: Department of Pediatrics, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: celeste.barreto@chln.min-saude.pt.
authors.forename: C
authors.initials: C
authors.lastname: Barreto
authors.affiliation: Pediatric Lung Function and Sleep Laboratory, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal; Respiratory Unit, Department of Pediatrics, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: terb@sapo.pt.
authors.forename: T
authors.initials: T
authors.lastname: Bandeira
authors.affiliation: Pediatric Lung Function and Sleep Laboratory, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal; Respiratory Unit, Department of Pediatrics, Hospital de Santa Maria, CHLN, Lisbon Academic Medical Center, Portugal. Electronic address: rosariotferreira@sapo.pt.
authors.forename: R
authors.initials: R
authors.lastname: Ferreira
mesh_terms: D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D010092:Oximetry; D017286:Polysomnography; D011446:Prospective Studies; D012120:Respiration Disorders / Q000209:etiology* / Q000503:physiopathology; D012893:Sleep Wake Disorders / Q000209:etiology* / Q000503:physiopathology; D013147:Spirometry
keywords: Children; Cystic fibrosis; Polysomnography; Sleep disturbance; Spirometry