title: Obstructive Sleep Apnea Risk, Asthma Burden, and Lower Airway Inflammation in Adults in the Severe Asthma Research Program (SARP) II.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) may worsen asthma, but large studies are lacking and the underlying mechanisms are unknown.
  
  
  OBJECTIVE
  The objective of this study was to determine the prevalence of OSA risk among patients with asthma of different severity compared with normal controls (NC), and among asthmatics, to test the relationship of OSA risk with asthma burden and airway inflammation.
  
  
  METHODS
  Subjects with severe (SA, n = 94) and nonsevere asthma (NSA, n = 161), and NC (n = 146) were recruited in an add-on substudy, to the observational Severe Asthma Research Program (SARP) II; subjects completed sleep quality, sleepiness and OSA risk (Sleep Apnea scale of the Sleep Disorders Questionnaire [SA-SDQ]) questionnaires, and clinical assessments. Sputum was induced in a subset of asthmatics.
  
  
  RESULTS
  Relative to NC, despite similar sleep duration, the subjects with SA and NSA had worse sleep quality, were sleepier, and had higher SA-SDQ scores. Among asthmatics, higher SA-SDQ was associated with increased asthma symptoms, β-agonist use, health care utilization, and worse asthma quality of life. A significant association of SA-SDQ with sputum polymorphonuclear cells% was noted: each increase in SA-SDQ by its standard deviation (6.85 units) was associated with a rise in % sputum neutrophils of 7.78 (95% CI 2.33-13.22, P = .0006), independent of obesity and other confounders.
  
  
  CONCLUSIONS
  OSA symptoms are more prevalent among asthmatics, in whom they are associated with higher disease burden. OSA risk is associated with a neutrophilic airway inflammation in asthma, which suggests that OSA may be an important contributor to the neutrophilic asthma. Further studies are necessary to confirm these findings and better understand the mechanistic underpinnings of this relationship.
authors.affiliation: James B. Skatrud Pulmonary/Sleep Research Laboratory, Medical Service, William S. Middleton Memorial Veterans Hospital, Madison, Wis; Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis; Center for Sleep Medicine and Sleep Research/Wisconsin Sleep, University of Wisconsin School of Medicine and Public Health, Madison, Wis. Electronic address: mt3@medicine.wisc.edu.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Teodorescu
authors.affiliation: James B. Skatrud Pulmonary/Sleep Research Laboratory, Medical Service, William S. Middleton Memorial Veterans Hospital, Madison, Wis; Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis.
authors.forename: Oleg
authors.initials: O
authors.lastname: Broytman
authors.affiliation: Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colo; Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Denver, Denver, Colo.
authors.forename: Douglas
authors.initials: D
authors.lastname: Curran-Everett
authors.affiliation: Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis.
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Sorkness
authors.affiliation: Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis.
authors.forename: Gina
authors.initials: G
authors.lastname: Crisafi
authors.affiliation: Department of Medicine, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: Eugene R
authors.initials: ER
authors.lastname: Bleecker
authors.affiliation: Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Serpil
authors.initials: S
authors.lastname: Erzurum
authors.affiliation: Division of Respiratory Medicine, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Gaston
authors.affiliation: Asthma Institute, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pa.
authors.forename: Sally E
authors.initials: SE
authors.lastname: Wenzel
authors.affiliation: Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis.
authors.forename: Nizar N
authors.initials: NN
authors.lastname: Jarjour
mesh_terms: D000328:Adult; D001249:Asthma / Q000453:epidemiology* / Q000276:immunology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D009765:Obesity / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology; D015995:Prevalence; D012129:Respiratory Function Tests; D012306:Risk; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology* / Q000276:immunology / Q000503:physiopathology; D013183:Sputum / Q000166:cytology; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Airway inflammation; Asthma; Obstructive; Sleep apnea