title: Surgical vs conventional therapy for weight loss treatment of obstructive sleep apnea: a randomized controlled trial.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is strongly related to obesity. Weight loss is recommended as part of the overall management plan for obese patients diagnosed with OSA.
  
  
  OBJECTIVE
  To determine whether surgically induced weight loss is more effective than conventional weight loss therapy in the management of OSA.
  
  
  METHODS
  A randomized controlled trial of 60 obese patients (body mass index: >35 and <55) with recently diagnosed (<6 months) OSA and an apnea-hypopnea index (AHI) of 20 events/hour or more. These patients had been prescribed continuous positive airway pressure (CPAP) therapy to manage OSA and were identified via accredited community sleep clinics. The trial was conducted between September 2006 and March 2009 by university- and teaching hospital-based clinical researchers in Melbourne, Australia. Patients with obesity hypoventilation syndrome, previous bariatric surgery, contraindications to bariatric surgery, or significant cardiopulmonary, neurological, vascular, gastrointestinal, or neoplastic disease were excluded.
  
  
  METHODS
  Patients were randomized to a conventional weight loss program that included regular consultations with a dietitian and physician, and the use of very low-calorie diets as necessary (n = 30) or to bariatric surgery (laparoscopic adjustable gastric banding; n = 30).
  
  
  METHODS
  The primary outcome was baseline to 2-year change in AHI on diagnostic polysomnography scored by staff blinded to randomization. Secondary outcomes were changes in weight, CPAP adherence, and functional status.
  
  
  RESULTS
  Patients lost a mean of 5.1 kg (95% CI, 0.8 to 9.3 kg) in the conventional weight loss program compared with 27.8 kg (95% CI, 20.9 to 34.7 kg) in the bariatric surgery group (P < .001). The AHI decreased by 14.0 events/hour (95% CI, 3.3 to 24.6 events/hour) in the conventional weight loss group and by 25.5 events/hour (95% CI, 14.2 to 36.7 events/hour) in the bariatric surgery group. The between-group difference was -11.5 events/hour (95% CI, -28.3 to 5.3 events/hour; P = .18). CPAP adherence did not differ between the groups. The bariatric surgery group had greater improvement in the Short Form 36 physical component summary score (mean, 9.3 [95% CI, 0.5 to 18.0]; P = .04).
  
  
  CONCLUSIONS
  Among a group of obese patients with OSA, the use of bariatric surgery compared with conventional weight loss therapy did not result in a statistically greater reduction in AHI despite major differences in weight loss.
  
  
  BACKGROUND
  anzctr.org Identifier: 12605000161628.
authors.affiliation: Obesity Research Unit, Department of General Practice, Monash University, Melbourne, Victoria, Australia. john.dixon@bakeridi.edu.au
authors.forename: John B
authors.initials: JB
authors.lastname: Dixon
authors.forename: Linda M
authors.initials: LM
authors.lastname: Schachter
authors.forename: Paul E
authors.initials: PE
authors.lastname: O'Brien
authors.forename: Kay
authors.initials: K
authors.lastname: Jones
authors.forename: Mariee
authors.initials: M
authors.lastname: Grima
authors.forename: Gavin
authors.initials: G
authors.lastname: Lambert
authors.forename: Wendy
authors.initials: W
authors.lastname: Brown
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Naughton
mesh_terms: D000328:Adult; D045422:Continuous Positive Airway Pressure; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000601:surgery*; D020181:Sleep Apnea, Obstructive / Q000150:complications*; D016896:Treatment Outcome; D015431:Weight Loss