Bariatric surgery and its impact on sleep architecture, sleep-disordered breathing, and metabolism.

Over the last several decades, the prevalence of obesity has increased significantly worldwide. This has translated into an increased prevalence of obesity-associated morbidities including sleep-disordered breathing and metabolic disorders. While the medical management of obesity is relatively ineffective, bariatric surgery is the most successful method for sustained weight loss and markedly reduces obesity-related morbidity and mortality. The anatomical changes created with different types of procedures lead to variable weight loss and improvement of co-morbidities; however the latter does not appear to be exclusively dependent on the amount of weight loss. Bariatric surgery does not always lead to complete resolution of obstructive sleep apnea and age, gender and severity of the obstructive sleep apnea predict the residual disease after peak weight loss. Metabolic disorders and specifically diabetes often improve dramatically early after the procedure, before any significant weight loss has occurred. The modified gastrointestinal anatomy and physiology may explain this phenomenon.