title: Effects of sleeve gastrectomy and medical treatment for obesity on glucagon-like peptide 1 levels and glucose homeostasis in non-diabetic subjects.
abstract: BACKGROUND
  The effects of medical and surgical treatments for obesity on glucose metabolism and glucagon-like peptide 1 (GLP-1) levels independent of weight loss remain unclear. This study aims to assess plasma glucose levels, insulin sensitivity and secretion, and GLP-1 levels before and after sleeve gastrectomy (SG) or medical treatment (MED) for obesity.
  
  
  METHODS
  This study is a prospective, controlled, non-randomised study. Two groups of non-diabetic obese patients with similar BMIs, including a SG group (BMI, 35.5 ± 0.9 kg/m(2); n = 6) and a MED group (BMI, 37.7 ± 1.9 kg/m(2); n = 6) and a group of lean subjects (BMI, 21.7 ± 0.7 kg/m(2); n = 8).
  
  
  RESULTS
  Plasma glucose, insulin, and total GLP-1 levels at fasting and after the intake of a standard liquid meal at baseline and at 2 months post-intervention. At baseline, total GLP-1 levels were similar, but obese patients had lower insulin sensitivity and higher insulin secretion than lean subjects. At 2 months post-intervention, SG and MED patients achieved similar weight loss (14.4 ± 0.8%, 15.3 ± 0.9%, respectively). Insulin sensitivity increased in SG and MED patients; however, postprandial insulin secretion decreased after MED, but not after SG. The incremental area under the curve of GLP-1 increased after SG (P = 0.04), but not after MED.
  
  
  CONCLUSIONS
  Weight loss by medical or surgical treatment improved insulin sensitivity. However, only MED corrected the hyperinsulinemic postprandial state associated to obesity. Postprandial GLP-1 levels increased significantly after SG without duodenal exclusion, which may explain why insulin secretion did not decrease following this surgery.
authors.affiliation: Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Catolica de Chile, Marcoleta 367, 6510260, Santiago, Chile.
authors.forename: Juan Patricio
authors.initials: JP
authors.lastname: Valderas
authors.forename: Veronica
authors.initials: V
authors.lastname: Irribarra
authors.forename: Lorena
authors.initials: L
authors.lastname: Rubio
authors.forename: Camilo
authors.initials: C
authors.lastname: Boza
authors.forename: Manuel
authors.initials: M
authors.lastname: Escalona
authors.forename: Yessica
authors.initials: Y
authors.lastname: Liberona
authors.forename: Andrea
authors.initials: A
authors.lastname: Matamala
authors.forename: Alberto
authors.initials: A
authors.lastname: Maiz
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D004038:Diet, Reducing; D005081:Exercise Therapy; D005260:Female; D005743:Gastrectomy / Q000379:methods; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000097:blood / Q000601:surgery / Q000628:therapy*; D011446:Prospective Studies; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D001786:Blood Glucose; D007328:Insulin; D052216:Glucagon-Like Peptide 1