ABSTRACT
Certain types of bariatric surgery increase incretin levels, including glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP). These hormones, which are predominantly secreted from the gut, are responsible for 50-60% of insulin secretion [1], and the incretin effect has been shown to be impaired in those with type 2 diabetes [2]. It has been hypothesized that manipulation of the gastrointestinal anatomy via certain types of bariatric surgeries leads to changes in incretin levels that impact metabolism and glucose homeostasis. This chapter will briey review physiology of incretins, provide a thorough review of the impact of different types of bariatric surgeries on incretin levels and associated improvements in metabolism and glucose homeostasis, present possible mechanisms for the changes in incretin levels and favorable metabolic effects after bariatric surgery, as well as discuss the signicance of the incretins in the context of energy balance and glucose metabolism.
