title: Bariatric Surgery or Non-Surgical Weight Loss for Obstructive Sleep Apnoea? A Systematic Review and Comparison of Meta-analyses.
abstract: BACKGROUND
  Obstructive sleep apnoea (OSA) is a well-recognised complication of obesity. Non-surgical weight loss (medical, behavioural and lifestyle interventions) may improve OSA outcomes, although long-term weight control remains challenging. Bariatric surgery offers a successful strategy for long-term weight loss and symptom resolution.
  
  
  OBJECTIVE
  To comparatively appraise bariatric surgery vs. non-surgical weight loss interventions in OSA treatment utilising body mass index (BMI) and apnoea-hypopnoea index (AHI) as objective measures of weight loss and apnoea severity.
  
  
  METHODS
  A systematic literature review revealed 19 surgical (n = 525) and 20 non-surgical (n = 825) studies reporting the primary endpoints of BMI and AHI before and after intervention. Data were meta-analysed using random effects modelling. Subgroup analysis, quality scoring and risk of bias were assessed.
  
  
  RESULTS
  Surgical patients had a mean pre-intervention BMI of 51.3 and achieved a significant 14 kg/m(2) weighted decrease in BMI (95%CI [11.91, 16.44]), with a 29/h weighted decrease in AHI (95%CI [22.41, 36.74]). Non-surgical patients had a mean pre-intervention BMI of 38.3 and achieved a significant weighted decrease in BMI of 3.1 kg/m(2) (95%CI [2.42, 3.79]), with a weighted decrease in AHI of 11/h (95%CI [7.81, 14.98]). Heterogeneity was high across all outcomes.
  
  
  CONCLUSIONS
  Both bariatric surgery and non-surgical weight loss may have significant beneficial effects on OSA through BMI and AHI reduction. However, bariatric surgery may offer markedly greater improvement in BMI and AHI than non-surgical alternatives. Future studies must address the lack of randomised controlled and comparative trials in order to confirm the exact relationship between metabolic surgery and non-surgical weight loss interventions in OSA resolution.
authors.affiliation: The Department of Surgery and Cancer, Imperial College London. 10th Floor, Queen Elizabeth the Queen Mother (QEQM) Building, Imperial College Healthcare NHS Trust at St Mary's Hospital, Praed Street, London, W2 1NY, UK, h.ashrafian@imperial.ac.uk.
authors.forename: Hutan
authors.initials: H
authors.lastname: Ashrafian
authors.forename: Tania
authors.initials: T
authors.lastname: Toma
authors.forename: Simon P
authors.initials: SP
authors.lastname: Rowland
authors.forename: Leanne
authors.initials: L
authors.lastname: Harling
authors.forename: Alan
authors.initials: A
authors.lastname: Tan
authors.forename: Evangelos
authors.initials: E
authors.lastname: Efthimiou
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
mesh_terms: D050110:Bariatric Surgery; D015992:Body Mass Index; D006801:Humans; D008019:Life Style; D009767:Obesity, Morbid / Q000150:complications / Q000601:surgery / Q000628:therapy*; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000601:surgery / Q000628:therapy*; D016896:Treatment Outcome; D015431:Weight Loss