title: Impaired secretion of glucagon-like peptide 1 during oral glucose tolerance test in patients with newly diagnosed type 2 diabetes mellitus.
abstract: OBJECTIVE
  To assess glucagon-like peptide 1 (GLP-1) secretion after oral glucose tolerance tests (OGTTs) in subjects with newly diagnosed type 2 diabetes mellitus (T2DM), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT) to clarify changes in GLP-1 secretion during the course of T2DM.
  
  
  METHODS
  In this cross sectional study, 80 subjects were divided into the NGT, IGT, and T2DM groups after undergoing a 75 g OGTT from March to December 2014 at the School of Medicine, First Affiliated Hospital, Shihezi University, Xinjiang, China. Plasma total GLP-1 was measured at 0, 30, 60, 120, and 180 minutes. Homeostasis model assessment of insulin resistance (HOMA-IR), islet β-cell function (HOMA-β), Gutt index, Matsuda index, incremental GLP-1 (ΔGLP-1), and areas under the curves of GLP-1 (AUCglp-1), glucose (AUCg), and insulin (AUCins) were calculated.
  
  
  RESULTS
  Plasma total GLP-1 at 30-120 minutes and ΔGLP-1 at 30-120 minutes were lower in the T2DM group than in the IGT and NGT groups (p less than 0.05). Peak GLP-1 levels were 35% lower in the T2DM group than in the NGT group. Plasma total GLP-1, ΔGLP-1, and AUCglp-1 correlated negatively with HOMA-IR and AUCg, and positively with HOMA-β, Gutt index, Matsuda index, and AUCins (p less than 0.05).
  
  
  CONCLUSIONS
  The GLP-1 secretion after 75 g OGTT was impaired in newly diagnosed T2DM patients, inversely proportional to IR and hyperglycemia, and positively correlated with β-cell function and insulin sensitivity.
authors.affiliation: Department of Endocrinology and Metabolism, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. E-mail. wxldoctor@126.com.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Ye
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Ling-Yun
authors.initials: LY
authors.lastname: Zhu
authors.forename: Gang
authors.initials: G
authors.lastname: Feng
authors.forename: Xiang-Yun
authors.initials: XY
authors.lastname: Chang
authors.forename: Kan
authors.initials: K
authors.lastname: Sun
mesh_terms: D000328:Adult; D019540:Area Under Curve; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D018149:Glucose Intolerance / Q000175:diagnosis / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged
chemical_list: D052216:Glucagon-Like Peptide 1