title: Effect of continuous positive airway pressure vs placebo continuous positive airway pressure on sleep quality in obstructive sleep apnea.
abstract: OBJECTIVE
  Continuous positive airway pressure (CPAP) therapy has become the treatment of choice for obstructive sleep apnea (OSA). However, the efficacy of CPAP therapy has not been evaluated against a suitable control. We investigated the effectiveness of CPAP therapy in improving sleep quality in patients with OSA. We hypothesized that CPAP improves sleep quality.
  
  
  METHODS
  Forty-eight CPAP-naive OSA patients were evaluated. None were receiving antihypertensive medications, and none had major medical illnesses.
  
  
  METHODS
  Patients were randomized to receive either CPAP or placebo CPAP (CPAP at an ineffective pressure) for 7 days in a double-blind fashion. Forty-one patients completed the protocol. Sleep quality variables, arousals, sleep arterial oxygen saturation (SaO(2)), and respiratory disturbance index (RDI) were assessed at baseline, after 1 day of treatment, and after 7 days of treatment. Repeated measures analysis of variance was used to evaluate the effects of treatment, time, and the interaction of the two.
  
  
  RESULTS
  As expected, CPAP lowered RDI and number of arousals, and increased SaO(2) over time (p = 0.001). Contrary to expectations, both CPAP and placebo CPAP had comparable effects on sleep quality as assessed by sleep architecture, sleep efficiency, total sleep time, and wake after sleep onset time.
  
  
  CONCLUSIONS
  This study confirms the effectiveness of CPAP in lowering the number of arousals and the RDI, and in raising SaO(2). However, our data suggest that short-term CPAP is no different than placebo in improving sleep architecture. Further evaluation of the effectiveness of CPAP using a suitable placebo CPAP in prospective randomized studies is needed
authors.affiliation: Department of Medicine, University of California San Diego, 92103-8378, USA. jloredo@ucsd.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Loredo
authors.forename: S
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: J E
authors.initials: JE
authors.lastname: Dimsdale
mesh_terms: D000328:Adult; D001143:Arousal; D004311:Double-Blind Method; D006801:Humans; D008875:Middle Aged; D017286:Polysomnography; D011175:Positive-Pressure Respiration; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D016896:Treatment Outcome