title: Updates in weight loss surgery and gastrointestinal peptides.
abstract: OBJECTIVE
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 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.
authors.forename: Maria Saur
authors.initials: MS
authors.lastname: Svane
authors.forename: Kirstine Nyvold
authors.initials: KN
authors.lastname: Bojsen-Møller
authors.forename: Sten
authors.initials: S
authors.lastname: Madsbad
authors.forename: Jens Juul
authors.initials: JJ
authors.lastname: Holst
mesh_terms: D001066:Appetite; D001647:Bile Acids and Salts / Q000378:metabolism; D005743:Gastrectomy; D015390:Gastric Bypass; D005768:Gastrointestinal Hormones / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D009767:Obesity, Morbid / Q000601:surgery*; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D001647:Bile Acids and Salts; D005768:Gastrointestinal Hormones