title: Effects of salmeterol on sleeping oxygen saturation in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Sleep is associated with important adverse effects in patients with chronic obstructive pulmonary disease (COPD), such as disturbed sleep quality and gas exchange, including hypoxemia and hypercapnia. The effects of inhaled long-acting beta(2)-agonist therapy (LABA) on these disturbances are unclear.
  
  
  OBJECTIVE
  The aim of the study was to assess the effect of inhaled salmeterol on nocturnal sleeping arterial oxygen saturation (SaO(2)) and sleep quality.
  
  
  METHODS
  In a randomized, double-blind, placebo-controlled, crossover study of moderate/severe stable COPD patients, we compared the effects of 4 weeks of treatment with salmeterol 50 microg b.d. and matching placebo on sleeping SaO(2) and sleep quality. Overnight polysomnography (PSG) was performed at baseline, and after 4 and 8 weeks in addition to detailed pulmonary function testing. Of 15 patients included, 12 completed the trial (median age 69 years, forced expiratory volume in 1 s, FEV(1): 39%).
  
  
  RESULTS
  Both mean SaO(2) [salmeterol vs. placebo: 92.9% (91.2, 94.7) vs. 91.0% (88.9, 94.8); p = 0.016] and the percentage of sleep spent below 90% of SaO(2) [1.8% (0.0, 10.8) vs. 25.6% (0.5, 53.5); p = 0.005] improved significantly with salmeterol. Sleep quality was similar with both salmeterol and placebo on PSG. Static lung volumes, particularly trapped gas volume, tended to improve with salmeterol.
  
  
  CONCLUSIONS
  We conclude that inhaled LABA therapy improves sleeping SaO(2) without significant change in sleep quality.
authors.affiliation: Sleep Research Laboratory, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Silke
authors.initials: S
authors.lastname: Ryan
authors.forename: Liam S
authors.initials: LS
authors.lastname: Doherty
authors.forename: Clare
authors.initials: C
authors.lastname: Rock
authors.forename: Geraldine M
authors.initials: GM
authors.lastname: Nolan
authors.forename: Walter T
authors.initials: WT
authors.lastname: McNicholas
mesh_terms: D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D017286:Polysomnography; D011653:Pulmonary Diffusing Capacity; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000188:drug therapy / Q000503:physiopathology; D000068299:Salmeterol Xinafoate; D012890:Sleep; D013147:Spirometry
chemical_list: D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents; D000068299:Salmeterol Xinafoate; D000420:Albuterol; D010100:Oxygen