title: Restoration of high-frequency glucose-entrained insulin oscillations in obese subjects with type 2 diabetes after biliopancreatic diversion.
abstract: BACKGROUND
  Minimal glucose infusions are known to entrain insulin oscillations in patients with normal glucose tolerance (NGT) but not in patients with type 2 diabetes (T2D).
  
  
  OBJECTIVE
  To investigate whether weight loss after a version of biliopancreatic diversion (BPD) can restore the glucose entrainment of high-frequency insulin oscillations in morbidly obese NGT or T2D patients.
  
  
  METHODS
  University Hospital, Greece.
  
  
  METHODS
  We prospectively studied 9 NGT controls (body mass index [BMI] 23.3±1.6 kg/m2), 9 obese NGT patients (BMI 51.1±12.7 kg/m2), and 9 obese T2D patients (BMI 56.8±11.6 kg/m2). Patients were studied before and 1.5 years after BPD. Insulin was sampled every minute for 90 minutes. Glucose (6 mg/kg weight) was infused every 10 minutes for 1 minute. Regularity of insulin pulses was estimated by autocorrelation analysis, spectral analysis, approximate entropy/sample entropy (ApEn/SampEn), and insulin pulsatility by deconvolution analysis.
  
  
  RESULTS
  Postoperatively, glucose and insulin concentrations of NGT and T2D patients decreased to control levels and BMI to 31.3±6.3 for NGT patients and 34.9±9.9 kg/m2for T2D patients. Preoperatively, glucose entrainment was absent in all T2D and in 4 NGT patients as assessed with spectral analysis and in 8 and 4, respectively, as assessed with autocorrelation and deconvolution analysis. Postoperatively, it was restored to normal in all patients. ApEn/SampEn decreased significantly only in the T2D group postoperatively.
  
  
  CONCLUSIONS
  BPD restores the glucose entrainment of high-frequency insulin oscillations in obese NGT and T2D patients after marked weight loss and normalizes glucose levels and insulin sensitivity, thus demonstrating recovery of β-cell glucose sensing.
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, University of Patras Medical School, Patras, Greece.
authors.forename: Angeliki S
authors.initials: AS
authors.lastname: Leonardou
authors.affiliation: Department of Medical Physics, University of Patras Medical School, Patras, Greece.
authors.forename: Christopher
authors.initials: C
authors.lastname: Karystianos
authors.affiliation: Department of Internal Medicine, Division of Nephrology, University of New Mexico, Albuquerque, New Mexico.
authors.forename: Christos
authors.initials: C
authors.lastname: Argyropoulos
authors.affiliation: Department of Medical Physics, University of Patras Medical School, Patras, Greece.
authors.forename: George C
authors.initials: GC
authors.lastname: Nikiforidis
authors.affiliation: Nutrition Support and Morbid Obesity Clinic, Department of Surgery, University of Patras Medical School, Patras, Greece.
authors.forename: Fotis
authors.initials: F
authors.lastname: Kalfarentzos
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, University of Patras Medical School, Patras, Greece. Electronic address: thalex@med.upatras.gr.
authors.forename: Theodore K
authors.initials: TK
authors.lastname: Alexandrides
mesh_terms: D000328:Adult; D015904:Biliopancreatic Diversion; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000601:surgery; D005215:Fasting / Q000097:blood; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D005951:Glucose Tolerance Test; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D050417:Insulin-Secreting Cells / Q000502:physiology; D008297:Male; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery; D011182:Postoperative Care; D011446:Prospective Studies; D013549:Sweetening Agents / Q000008:administration & dosage / Q000494:pharmacology; D015431:Weight Loss / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013549:Sweetening Agents; D005947:Glucose
keywords: Bariatric surgery; Glucose entrainment; Insulin oscillations; Type 2 diabetes