title: Insulin response to oral stimuli and glucose effectiveness increased in neuroglycopenia following gastric bypass.
abstract: OBJECTIVE
  Hyperinsulinemic hypoglycemia with neuroglycopenia is a rare complication following Roux-en-Y gastric bypass (RYGB) surgery for weight management. Insulin secretion and action in response to oral and intravenous stimuli in persons with and without neuroglycopenia following RYGB are evaluated in this study.
  
  
  METHODS
  Cross-sectional cohort studies were performed at a single academic institution to assess insulin secretion and action during oral mixed meal tolerance test and intravenous glucose tolerance test (IVGTT).
  
  
  RESULTS
  Insulin secretion was increased more following oral mixed meal than intravenous glucose in individuals with neuroglycopenia compared to the asymptomatic group. Reduced insulin clearance did not contribute to higher insulinemia. Glucose effectiveness at zero insulin, estimated during the IVGTT, was also higher in those with neuroglycopenia. Insulin sensitivity did not differ between groups.
  
  
  CONCLUSIONS
  Increased beta-cell response to oral stimuli and insulin-independent glucose disposal may both contribute to severe hypoglycemia after RYGB.
authors.affiliation: Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Mary Elizabeth
authors.initials: ME
authors.lastname: Patti
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Allison B
authors.initials: AB
authors.lastname: Goldfine
mesh_terms: D001786:Blood Glucose; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D005951:Glucose Tolerance Test; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery
chemical_list: D001786:Blood Glucose; D007328:Insulin