title: Clinical predictors of sleep apnoea in heart failure outpatients.
abstract: BACKGROUND
  Sleep-disordered breathing (SDB) is common in heart failure patients. Many of them still remain undiagnosed. The aim of this study was to detect clinical predictors of sleep apnoea which may help to identify patients with SDB at a heart failure clinic.
  
  
  METHODS
  We performed an in-home sleep study on 115 consecutive patients from our heart failure clinic. Clinical characteristics, blood samples, daytime sleepiness and quality of life were registered.
  
  
  RESULTS
  Among 115 patients, 52% had moderate to severe SDB. Body Mass Index (BMI) ≥ 30 kg/m² was the only independent predictor of moderate to severe SDB [Odds ratio (OR) = 3.62, 95% Confidence interval (CI) 1.40-9.36, p = 0.008]. Quality of life and level of sleepiness were not significantly associated with SDB. Patients with mild to moderate chronic obstructive pulmonary disease (COPD) were unlikely to have SDB compared with patients without COPD (OR = 0.10, 95% CI 0.02-0.43, p = 0.002). Hypertension was a predictor of having obstructive sleep apnoea (OR = 2.78, 95% CI 1.15-6.75, p = 0.02), while haemoglobin ≥ 15 g/dl was associated with central sleep apnoea (OR = 6.71, 95% CI 1.96-22.99, p = 0.002).
  
  
  CONCLUSIONS
  BMI ≥ 30 kg/m(2) is associated with moderate to severe SDB, both obstructive and central sleep apnoea. Thus, BMI may be used as one of the selection criteria for referral of heart failure patients to a sleep specialist.
authors.affiliation: Department of Cardiology, Lovisenberg Diakonale Hospital, Oslo, Norway.
authors.forename: T E
authors.initials: TE
authors.lastname: Herrscher
authors.forename: H
authors.initials: H
authors.lastname: Akre
authors.forename: B
authors.initials: B
authors.lastname: Overland
authors.forename: L
authors.initials: L
authors.lastname: Sandvik
authors.forename: A S
authors.initials: AS
authors.lastname: Westheim
mesh_terms: D015992:Body Mass Index; D005260:Female; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D008297:Male; D010045:Outpatients; D011788:Quality of Life; D012891:Sleep Apnea Syndromes / Q000175:diagnosis*