Hormone changes affecting energy homeostasis after metabolic surgery

Worldwide, there is an epidemic of obesity and its associated diseases. The past decade of research has brought about a paradigm shift in our understanding of both the mechanisms underlying energy homeostasis and the multiple factors contributing to the pathophysiology of obesity. Metabolic surgery is currently far more effective than diet and exercise or pharmacotherapy in achieving durable weight loss. Moreover, the remarkable results of surgery in achieving a rapid remission of type 2 diabetes mellitus has sparked tremendous excitement and research into the mechanisms through which metabolic surgery has its dramatic effect. As opposed to the traditional understanding of "restriction" and "malabsorption," current evidence suggests that metabolic surgery alters the expression of multiple hormones that affect both short-term and long-term signals of energy balance. We review the hormonal changes following the most common types of metabolic operations currently being performed. The profile of hormonal changes provides a guide to tailor the choice of operation for each individual patient toward achieving the desired metabolic result. In the future, individualized metabolic surgery alone or modulated by targeted pharmacological therapy may achieve the most reliable and effective results with the highest safety and lowest side effect profile.