Metabolic surgery and obstructive sleep apnoea: the protective effects of bariatric procedures
- Hutan Ashrafian1,2,
- Carel W le Roux2,
- Simon P Rowland1,
- Mariam Ali1,
- Andrew R Cummin3,
- Ara Darzi1,
- Thanos Athanasiou1
- 1The Department of Surgery and Cancer, Imperial College London, London, UK
- 2Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, UK
- 3National Heart and Lung Institute, Imperial College London, London, UK
- Correspondence to Hutan Ashrafian, Clinical Lecturer in Surgery and Wellcome Trust Research Fellow, 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;
- Received 11 September 2010
- Accepted 8 March 2011
- Published Online First 27 June 2011
The global epidemic of obesity and the worldwide prevalence of obstructive sleep apnoea (OSA) are both increasing. Epidemiological studies reveal an association between obesity, weight gain and OSA. Metabolic or bariatric operations provide sustained weight loss and resolve or improve the symptoms of OSA in the majority of morbidly obese individuals. These operations also modulate the metabolic profile to improve glycaemic control, to decrease cardiovascular risk and obesity-related mortality. The beneficial effects of metabolic operations on OSA include mechanical weight-dependent and metabolic weight-independent effects that are achieved through the BRAVE effects: (Bile flow alteration; Reduction of gastric size; Anatomical gut rearrangement and altered flow of nutrients; Vagal manipulation; and Enteric gut hormone modulation). These result in an improvement in insulin resistance, adipokines, cytokines and systemic inflammation. A literature analysis was performed with statistical pooling of available surgical and medical studies to determine whether the weighted mean decrease in body mass index and sleep apnoea severity (measured by the apnoea-hypopnoea index) are larger in metabolic surgical studies than in non-surgical weight loss studies (diet, exercise and medication). However, heterogeneity across available trials, poor follow-up measures and a deficiency in comparative studies between surgical and non-surgical therapy precludes definitive statements regarding the relative benefits of surgical therapy. Further research is required to quantify robustly the effects and mechanisms of sleep apnoea resolution by metabolic surgery, which may reveal novel non-surgical treatments or enhanced surgical strategies in the management of this multisystem sleep disorder.
Funding Wellcome Trust.
Provenance and peer review Not commissioned; externally peer reviewed.