title: ß-cell pancreatic dysfunction plays a role in hyperglycemic peaks observed after gastric bypass surgery of obese patients.
abstract: BACKGROUND
  Early and intense hyperglycemic peaks are observed after Roux-en-Y gastric bypass (RYGB).
  
  
  OBJECTIVE
  The aim of this observational study was to compare the ß-cell pancreatic function of patients with (PEAK) and without hyperglycemic peaks (NOPEAK).
  
  
  METHODS
  Referral bariatric surgery center.
  
  
  METHODS
  Insulin secretion rate, clearance, and sensitivity and ß-cell and rate sensitivities were computed after a 75-g oral glucose tolerance test in 42 patients who underwent RYGB.
  
  
  RESULTS
  PEAK patients (n = 18; 30-min glycemia>10.4 mmol/L) did not differ from NOPEAK patients (n = 24) in their presurgery or weight loss characteristics. PEAK patients had significantly higher plasma concentrations of glucose and C-peptide than did NOPEAK patients, whereas insulin and glucagon-like peptide-1 concentrations did not differ. The insulin secretion rate and whole-body insulin clearance (208%) were significantly greater, but insulin sensitivity was significantly less (48%) in PEAK patients. Insulin secretion normalized to plasma glucose was significantly lower in PEAK patients, and the disposition index was reduced (35% to 41% of the values in NOPEAK patients).
  
  
  CONCLUSIONS
  We conclude that RYGB reveals a series of dysfunctions leading to hyperglycemia in a subset of patients. In PEAK patients, an insufficient adaptation of ß-cell function to glycemia, an increased insulin clearance, and a decreased insulin sensitivity cumulated to contribute to hyperglycemic peaks.
authors.affiliation: Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Vaurs
authors.affiliation: INSERM U1046, Heart and Muscle Pathophysiology and Experimental Medicine, Metabolic Exploration Unit (CERAMM), Service Central de Physiologie Clinique, Hôpital Lapeyronie, CHU de Montpellier, France.
authors.forename: Jean-Frédéric
authors.initials: JF
authors.lastname: Brun
authors.affiliation: Department of Epidemiology, Health Economics and Public Health, UMR1027 INSERM-University of Toulouse 3, CHU de Toulouse, Toulouse, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Bérard
authors.affiliation: Bariatric Surgery Department, CHU de Toulouse, Toulouse, France.
authors.forename: Mael
authors.initials: M
authors.lastname: Chalret du Rieu
authors.affiliation: Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Hanaire
authors.affiliation: Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France; Department of Epidemiology, Health Economics and Public Health, UMR1027 INSERM-University of Toulouse 3, CHU de Toulouse, Toulouse, France. Electronic address: patrick.ritz@wanadoo.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ritz
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology; D015390:Gastric Bypass; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D007003:Hypoglycemia / Q000097:blood / Q000209:etiology; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000502:physiology*; D009765:Obesity / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D010182:Pancreatic Diseases / Q000503:physiopathology*; D011183:Postoperative Complications / Q000097:blood / Q000503:physiopathology; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin
keywords: Bariatric surgery; C-Peptide; Continuous glucose monitoring; Diabetes; Dumping syndrome; Modeling insulin secretion