title: Outcomes in patients with chronic obstructive pulmonary disease and obstructive sleep apnea: the overlap syndrome.
abstract: BACKGROUND
  Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) (overlap syndrome) are more likely to develop pulmonary hypertension than patients with either condition alone.
  
  
  OBJECTIVE
  To assess the relation of overlap syndrome to mortality and first-time hospitalization because of COPD exacerbation and the effect of continuous positive airway pressure (CPAP) on these major outcomes.
  
  
  METHODS
  We included 228 patients with overlap syndrome treated with CPAP, 213 patients with overlap syndrome not treated with CPAP, and 210 patients with COPD without OSA. All were free of heart failure, myocardial infarction, or stroke. Median follow-up was 9.4 years (range, 3.3-12.7). End points were all-cause mortality and first-time COPD exacerbation leading to hospitalization.
  
  
  RESULTS
  After adjustment for age, sex, body mass index, smoking status, alcohol consumption, comorbidities, severity of COPD, apnea-hypopnea index, and daytime sleepiness, patients with overlap syndrome not treated with CPAP had a higher mortality (relative risk, 1.79; 95% confidence interval, 1.16-2.77) and were more likely to suffer a severe COPD exacerbation leading to hospitalization (relative risk, 1.70; 95% confidence interval, 1.21-2.38) versus the COPD-only group. Patients with overlap syndrome treated with CPAP had no increased risk for either outcome compared with patients with COPD-only.
  
  
  CONCLUSIONS
  The overlap syndrome is associated with an increased risk of death and hospitalization because of COPD exacerbation. CPAP treatment was associated with improved survival and decreased hospitalizations in patients with overlap syndrome.
authors.affiliation: Respiratory Service, Hospital Universitario Miguel Servet, Zaragoza 50009, Spain. jmmarint@unizar.es
authors.forename: Jose M
authors.initials: JM
authors.lastname: Marin
authors.forename: Joan B
authors.initials: JB
authors.lastname: Soriano
authors.forename: Santiago J
authors.initials: SJ
authors.lastname: Carrizo
authors.forename: Ana
authors.initials: A
authors.lastname: Boldova
authors.forename: Bartolome R
authors.initials: BR
authors.lastname: Celli
mesh_terms: D000367:Age Factors; D045422:Continuous Positive Airway Pressure; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000401:mortality*; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000401:mortality* / Q000628:therapy