title: Post-prandial hypoglycemia results from a non-glucose-dependent inappropriate insulin secretion in Roux-en-Y gastric bypassed patients.
abstract: BACKGROUND
  After Roux-en-Y gastric bypass (RYGB), hypoglycemia can occur and be associated with adverse events such as intense malaise and impaired quality of life.
  
  
  OBJECTIVE
  To compare insulin secretion, sensitivity, and clearance between two groups of patients, with or without hypoglycemia, after an oral glucose tolerance test (OGTT 75-g), and also to compare real-life glucose profiles within these two groups.
  
  
  METHODS
  Bariatric surgery referral center.
  
  
  METHODS
  This study involves a prospective cohort of 46 consecutive patients who complained of malaise compatible with hypoglycemia after RYGB, in whom an OGTT 75-g was performed. A plasma glucose value of lower than 2.8 mmol/L (50 mg/dl) between 90 and 120 min after the load was considered to be a significant hypoglycemia. The main outcome measures were insulin sensitivity, beta-cell function, and glycemic profiles during the test. Glucose parameters were also evaluated by continuous glucose monitoring (CGM) in a real-life setting in 43 patients.
  
  
  RESULTS
  Twenty-five patients had plasma glucose that was lower than 2.8 mmol/L between 90 and 120 from the load (HYPO group). Twenty-one had plasma glucose that was higher than 2.8 mmol/L (NONHYPO group). The HYPO patients were younger, had lost more weight after RYGB, were less frequently diabetic before surgery, and displayed higher early insulin secretion rates compared with the NONHYPO patients after the 75-g OGTT, and they had lower late insulin secretion rates. The HYPO patients had lower interstitial glucose values in real life, which suggests that a continuum exists between observations with an oral glucose load and real-life interstitial glucose concentrations.
  
  
  CONCLUSIONS
  This study suggests that HYPO patients after RYGB display an early increased insulin secretion rate when tested with an OGTT. CGM shows that HYPO patients spend more time below 3.3 mmol/L when compared with NONHYPO patients. This phenotype of patients should be monitored carefully after RYGB.
authors.affiliation: Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France. Electronic address: vaurscharlotte@yahoo.fr.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Vaurs
authors.affiliation: U1046 INSERM "Physiopathologie & Médecine Expérimentale du Cœur et des Muscles", Metabolic explorations Unit, Clinical Physiology Department, CHU Montpellier, Montpellier, France.
authors.forename: Jean-Frederic
authors.initials: JF
authors.lastname: Brun
authors.affiliation: Cardiovascular and Metabolic Disease Department, CHU de Toulouse, Toulouse, France.
authors.forename: Monelle
authors.initials: M
authors.lastname: Bertrand
authors.affiliation: UMR1048 INSERM-University of Toulouse III, Toulouse, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Burcelin
authors.affiliation: Bariatric Surgery Department, CHU de Toulouse, Toulouse, France.
authors.forename: Mael Chalret
authors.initials: MC
authors.lastname: du Rieu
authors.affiliation: Bariatric Surgery Department, Clinique des Cèdres, Cornebarieu, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Anduze
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 III, Toulouse University Hospital (CHU), Toulouse, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ritz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects* / Q000523:psychology; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006801:Humans; D007003:Hypoglycemia / Q000097:blood*; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D011446:Prospective Studies; D015431:Weight Loss; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose
keywords: Continuous glucose monitoring; Gastric bypass; Hypoglycemia; Insulin secretion