In this chapter, Dr Schirmer and Dr Hallowell provide a detailed and comprehensive overview of the surgical management of morbid obesity. The authors appropriately point out the tremendous worldwide impact that the obesity epidemic will have in the coming years. The chapter provides excellent clinical and technical advice from two experienced bariatric surgeons, and there is little to add regarding the thoughtful approach to patient care that the authors outline. There are, however, several areas within bariatric surgery that remain controversial. The field of bariatric surgery continues to evolve, and new procedures, new technologies, and expanding indications for surgery provide excellent opportunities for research, innovation, and debate. We address several of these areas in our commentary to this excellent chapter.
As the obesity epidemic has gained recognition as a major public health issue, though, the closely associated epidemic of type 2 diabetes mellitus (T2DM) has also emerged. In fact, the number of people with diabetes mellitus worldwide has more than doubled in the last three decades.1 In 2010, an estimated 285 million people worldwide had diabetes and this is projected to increase to 439 million by the year 2030.2 This staggering number represents nearly 8% of the world population between ages 20 and 79. In addition, while there is little argument that preventative and societal measures must be taken to mitigate this crisis, the importance of having safe, effective, and durable therapies for patients who already have these diseases has taken on greater importance.
The surgical treatment of diabetes, or metabolic surgery, is now gaining acceptance even among physicians who were ardent critics of this concept several years ago. Important advances in our understanding of how these operations effect glucose homeostasis are emerging and partly account for the increased acceptance. Insulin sensitivity improves due to weight loss (visceral fat loss). In addition, several studies suggest that an enhanced incretin effect driven by increased secretion of gut hormones such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) may account for improvement in insulin secretion following bypass procedures but not purely restrictive operations.3,4 Improvements in insulin secretion occur rapidly, even before much weight loss occurs, explaining why remission of diabetes may occur so quickly after bypass surgery.5 Much more investigation into mechanisms of diabetes improvement after metabolic surgery is required to gain a clear understanding of how these operations effect glucose homeostasis.
Convincing clinical outcomes resulting in diabetes remission rates of 40–80% have provided a foundation for a more collaborative effort between medical and surgical colleagues in treating this disease. This effort began in earnest at the 2007 Diabetes Surgery Summit in Rome6 and was followed by the American Diabetes Association's recognition of the role of bariatric surgery in the treatment of diabetes in 2009.7 More recently, the International Diabetes Federation (IDF), an umbrella organization of more than 200 national diabetes associations in more than 160 countries, published a position statement on ...