Updates in weight loss surgery and gastrointestinal peptides

Svane, Maria Saur^a,b; Bojsen-Møller, Kirstine Nyvold^a,b; Madsbad, Sten^a,b; Holst, Jens Juul^b

^aDepartment of Endocrinology, Hvidovre University Hospital, Hvidovre

^bDepartment of Biomedical Sciences and NNF Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark

Correspondence to Jens Juul Holst, Department of Biomedical Sciences and NNF Center for Basic Metabolic Research, Faculty of Health Sciences, Panum Institute, University of Copenhagen, DK-2200 Copenhagen, Denmark. Tel: +45 28751818; e-mail:[email protected]

Current Opinion in Endocrinology & Diabetes and Obesity22(1):p 21-28, February 2015. |DOI:10.1097/MED.0000000000000131

Abstract

Purpose of review

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy are referred to as ‘metabolic surgery’ due to hormonal shifts with impacts on diabetes remission and weight loss. The purpose of this review is to summarize recent findings in mechanisms underlying beneficial effects of weight loss surgery.

Recent findings

Importantly, gut hormone secretion is altered after RYGB and sleeve gastrectomy due to accelerated transit of nutrients to distal parts of the small intestine, leading to excessive release of L-cell peptide hormones [e.g. glucagon-like peptide-1 (GLP-1), peptide YY].

Improved glucose metabolism after RYGB and sleeve gastrectomy involves several mechanisms: early increased hepatic insulin sensitivity, resulting from reduced liver fat content in response to the postoperative caloric restriction, improved beta-cell function mediated by exaggerated postprandial GLP-1 secretion; as demonstrated by relapse of impaired glucose tolerance in studies blocking the GLP-1 receptor by exendin 9–39, and later after major weight loss increased peripheral insulin sensitivity. Gut hormone secretion changes towards a more anorectic profile and is likely important for less caloric intake and weight loss.

Summary

Changes in gut hormone secretion after RYGB and sleeve gastrectomy surgery induce the beneficial effects on weight and glycemic control through the influence on appetite regulation and insulin secretion.