title: Obesity-hypoventilation syndrome: increased risk of death over sleep apnea syndrome.
abstract: OBJECTIVE
  To study whether mortality and cardiovascular morbidity differ in non-invasive ventilation (NIV)-treated patients with severe obesity-hypoventilation syndrome (OHS) as compared with CPAP-treated patients with obstructive sleep apnea syndrome (OSAS), and to identify independent predictors of mortality in OHS.
  
  
  METHODS
  Two retrospective cohorts of OHS and OSAS were matched 1:2 according to sex, age (± 10 year) and length of time since initiation of CPAP/NIV therapy (± 6 months).
  
  
  RESULTS
  Three hundred and thirty subjects (110 patients with OHS and 220 patients with OSAS) were studied. Mean follow-up time was 7 ± 4 years. The five year mortality rates were 15.5% in OHS cohort and 4.5% in OSAS cohort (p< 0.05). Patients with OHS had a 2-fold increase (OR 2; 95% CI: 1.11-3.60) in the risk of mortality and 1.86 fold (OR 1.86; 95% CI: 1.14-3.04) increased risk of having a cardiovascular event. Diabetes, baseline diurnal SaO2 < 83%, EPAP < 7 cmH2O after titration and adherence to NIV < 4 hours independently predicted mortality in OHS.
  
  
  CONCLUSIONS
  Mortality of severe OHS is high and substantially worse than that of OSAS. Severe OHS should be considered a systemic disease that encompasses respiratory, metabolic and cardiovascular components that require a multimodal therapeutic approach.
authors: Respiratory Division and Sleep Disorders Unit, Lucus Augusti University Hospital, Galician Health Service, Lugo, Spain.
authors: Olalla
authors: O
authors: Castro-Añón
authors: Respiratory Division and Sleep Disorders Unit, Lucus Augusti University Hospital, Galician Health Service, Lugo, Spain.
authors: Luis A
authors: LA
authors: Pérez de Llano
authors: Lucus Augusti University Hospital, Galician Health Service, Lugo, Spain.
authors: Sandra
authors: S
authors: De la Fuente Sánchez
authors: Respiratory Division and Sleep Disorders Unit, Lucus Augusti University Hospital, Galician Health Service, Lugo, Spain.
authors: Rafael
authors: R
authors: Golpe
authors: Respiratory Division and Sleep Disorders Unit, Lucus Augusti University Hospital, Galician Health Service, Lugo, Spain.
authors: Lidia
authors: L
authors: Méndez Marote
authors: Galician Health Service, Lugo, Spain.
authors: Julián
authors: J
authors: Castro-Castro
authors: Department of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors: Arturo
authors: A
authors: González Quintela
mesh_terms: D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010845:Obesity Hypoventilation Syndrome / Q000401:mortality* / Q000628:therapy; D012189:Retrospective Studies; D012306:Risk; D020181:Sleep Apnea, Obstructive / Q000401:mortality* / Q000628:therapy