Endocrine Abstracts

Appetite can be better defined as hunger and fullness. Both of these change significantly after bariatric surgery. Gut hormones such as Peptide YY (PYY) and Glucagon like peptide-1 (GLP-1) are gastrointestinal peptides implicated in appetite control and glycaemic homeostasis. In non-obese individuals these satiety gut hormones may be attenuated. Given that PYY and GLP-1 are secreted from enteroendocrine L cells in the intestine, it is not surprising that manipulation of the gastrointestinal tract has been shown to alter their secretion; particularly when this intestinal manipulation is designed to aid weight reduction. PYY and GLP-1 dynamics are altered by bariatric surgery, with an improved secretory response to nutrient intake.

However, there remains a debate regarding the mechanisms responsible for the alterations in PYY and GLP-1 dynamics. We will review the evidence for gut hormone dynamics after Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB), biliopancreatic diversion (BPD) and sleeve gastrectomy (SG), and make comparisons between modalities. In addition, we will review the potential mechanisms underlying theses dynamics, other molecules that may add to the ‘incretin effect’ and other possible roles for GLP-1 following bariatric surgery. In summary the evidence presented will make the case why if patients are eligible and are interested in bariatric surgery they should be encouraged to have surgery provided they can be supported long term within multidisciplinary teams.