title: Potential underdiagnosis of obstructive sleep apnoea in the cardiology outpatient setting.
abstract: BACKGROUND
  Consistent evidence suggests that obstructive sleep apnoea (OSA) is associated with increased cardiovascular risk. However, it is unclear whether OSA is underdiagnosed in the cardiology outpatient setting. In the present study, we prospectively evaluated the potential underdiagnosis of OSA in several subspecialties from a tertiary cardiology university hospital.
  
  
  METHODS
  Consecutive outpatients from five subspecialties (hypertension, coronary, arrhythmia, heart failure (HF), valvular heart disease) were studied. We performed anthropometric measurements, assessed the risk of OSA using the Berlin Questionnaire and evaluated the prior diagnosis and treatment for OSA. In a subset of patients randomly selected, we performed portable sleep monitoring to objectively evaluate the presence of OSA (defined by an apnoea-hypopnoea index ≥15 events/h of sleep).
  
  
  RESULTS
  We evaluated 500 patients (100 from each subspecialty). The mean age and body mass index (BMI) were 59±13 years and 28.2±5.3 kg/m(2), respectively. We found that 51.6% (258 patients) had a high risk for OSA (Berlin Questionnaire). However, only 13 (3.1%) of these patients had a previous diagnosis of OSA. Of those, only six patients were receiving specific OSA treatment. Fifty patients (10 from each specialty) participated in sleep studies. No differences were found in patients who underwent sleep monitoring and those who did not. We found a high frequency of OSA (66%), varying from 50% (hypertension group) to 80% (HF group).
  
  
  CONCLUSIONS
  Despite significant scientific evidence pointing to OSA as an emerging cardiovascular risk factor, OSA is still underdiagnosed in several cardiology subspecialties.
authors.affiliation: Hypertension Unit, Cardiology Division, Heart Institute (InCor), Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Lucas E
authors.initials: LE
authors.lastname: Costa
authors.affiliation: Hypertension Unit, Cardiology Division, Heart Institute (InCor), Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Carlos Henrique G
authors.initials: CH
authors.lastname: Uchôa
authors.affiliation: Hypertension Unit, Cardiology Division, Heart Institute (InCor), Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Rebeca R
authors.initials: RR
authors.lastname: Harmon
authors.affiliation: Hypertension Unit, Cardiology Division, Heart Institute (InCor), Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Bortolotto
authors.affiliation: Sleep Laboratory, Pulmonary Division, Heart Institute (InCor), Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Geraldo
authors.initials: G
authors.lastname: Lorenzi-Filho
authors.affiliation: Hypertension Unit, Cardiology Division, Heart Institute (InCor), Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil.
authors.forename: Luciano F
authors.initials: LF
authors.lastname: Drager
mesh_terms: D000368:Aged; D000886:Anthropometry / Q000379:methods; D001145:Arrhythmias, Cardiac / Q000453:epidemiology*; D003327:Coronary Disease / Q000453:epidemiology*; D003951:Diagnostic Errors / Q000517:prevention & control*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology*; D006349:Heart Valve Diseases / Q000453:epidemiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010045:Outpatients / Q000706:statistics & numerical data; D017286:Polysomnography / Q000379:methods*; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000628:therapy