The role of glucagon after bariatric/metabolic surgery: much more than an “anti-insulin” hormone.

Abstract

Background: It has recently been proposed that biological activity of glucagon has a dual function beyond stimulating hepatic glucose production, but also showing a paradoxical insulinotropic effect, which could suppose a new role of glucagon in the pathophysiological mechanisms of type 2 diabetes mellitus (T2DM). On the other hand, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) have also been developed, with surprising effects against T2DM. The aim of this review is to collect the information about the role of glucagon in pathophysiologic events involved in T2DM improvement after these surgeries. Results: After reviewing the 160 articles included in this study, an insulinotropic role for glucagon after B/M surgery through GLP1r in the beta-cell population arises. This effect seems to be modulated by another proglucagon family members such as GLP-1, GIP or Oxintomodulin, playing a key function on the B/M surgery beneficial effects and complications. Conclusions: Glucagon has a dual role after RYGB or SG. In addition to maintain blood glucose level it shows an insulinotropic effect which leads to be more than an “anti-insulin hormone”.