title: GLP-1 and peptide YY secretory response after fat load is impaired by insulin resistance, impaired fasting glucose and type 2 diabetes in morbidly obese subjects.
abstract: OBJECTIVE
  Both glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are gut hormones involved in energy homoeostasis. Obesity, insulin resistance and hyperglycaemia are significant confounders when GLP-1 and PYY secretion is assessed. Thus, we evaluated GLP-1 and PYY response after fat load in morbidly obese patients with different degrees of insulin resistance and glycemic status.
  
  
  METHODS
  We studied 40 morbidly obese subjects (mean age, 40·6 ± 1·3 years; mean BMI, 53·1 ± 1·2 kg/m(2) ) divided into groups according to their glycemic status: normal fasting glucose (NFG) group, impaired fasting glucose (IFG) group and type 2 diabetes mellitus (T2D) group. NFG patients were additionally subclassified, according to the homoeostasis model assessment of insulin resistance (HOMAIR ), into a low insulin-resistance (LIR) group (HOMAIR <3·9) or a high insulin-resistance (HIR) group (HOMAIR ≥3·9).
  
  
  METHODS
  Lipid emulsion was administered orally and measurements made at baseline and 180 min postprandially of levels of GLP-1, PYY, insulin, glucose, free fatty acids, triglycerides and leptin.
  
  
  RESULTS
  At the 180-minute postprandial reading, GLP-1 and PYY had increased in LIR-NFG subjects (41·84%, P = 0·01; 35·7%, P = 0·05; respectively), whereas no changes were observed in HIR-NFG, IFG or T2D subjects.
  
  
  CONCLUSIONS
  These results suggest that in morbidly obese subjects, both insulin resistance and abnormal glucose metabolism (IFG or T2D) impair the GLP-1 and PYY response to fat load. The implications of this attenuated enteroendocrine response should be elucidated by further studies.
authors.affiliation: Department of Endocrinology, Virgen de la Victoria University Hospital, Málaga, Spain; Research laboratory, Virgen de la Victoria University Hospital, Málaga, Spain; Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBERObn CB06/003), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: José C
authors.initials: JC
authors.lastname: Fernández-García
authors.forename: Mora
authors.initials: M
authors.lastname: Murri
authors.forename: Leticia
authors.initials: L
authors.lastname: Coin-Aragüez
authors.forename: Juan
authors.initials: J
authors.lastname: Alcaide
authors.forename: Rajaa
authors.initials: R
authors.lastname: El Bekay
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Tinahones
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005215:Fasting; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006706:Homeostasis; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood*; D019894:Peptide YY / Q000097:blood*
chemical_list: D001786:Blood Glucose; D008055:Lipids; D019894:Peptide YY; D052216:Glucagon-Like Peptide 1