title: The effect of vagal nerve blockade using electrical impulses on glucose metabolism in nondiabetic subjects.
abstract: OBJECTIVE
  Vagal interruption causes weight loss in humans and decreases endogenous glucose production in animals. However, it is unknown if this is due to a direct effect on glucose metabolism. We sought to determine if vagal blockade using electrical impulses alters glucose metabolism in humans.
  
  
  METHODS
  We utilized a randomized, cross-over study design where participants were studied after 2 weeks of activation or inactivation of vagal nerve blockade (VNB). Seven obese subjects with impaired fasting glucose previously enrolled in a long-term study to examine the effect of VNB on weight took part. We used a standardized triple-tracer mixed meal to enable measurement of the rate of meal appearance, endogenous glucose production, and glucose disappearance. The 550 kcal meal was also labeled with (111)In-diethylene triamine pentaacetic acid (DTPA) to measure gastrointestinal transit. Insulin action and β-cell responsivity indices were estimated using the minimal model.
  
  
  RESULTS
  Integrated glucose, insulin, and glucagon concentrations did not differ between study days. This was also reflected in a lack of effect on β-cell responsivity and insulin action. Furthermore, fasting and postprandial endogenous glucose production, integrated meal appearance, and glucose disposal did not differ in the presence or absence of VNB. Similarly, gastric emptying and colonic transit were unchanged by VNB.
  
  
  CONCLUSIONS
  In this pilot study in nondiabetic humans, electrical vagal blockade had no acute effects on glucose metabolism, insulin secretion and action, or gastric emptying. It remains to be determined if more pronounced effects would be observed in diabetic subjects.
authors: Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors: Matheni
authors: M
authors: Sathananthan
authors: Division of General Surgery, University of Minnesota, Minneapolis, MN, USA.
authors: Sayeed
authors: S
authors: Ikramuddin
authors: Division of General Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA ; Scottsdale Healthcare Bariatric Center, Scottsdale, AZ, USA.
authors: James M
authors: JM
authors: Swain
authors: Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors: Meera
authors: M
authors: Shah
authors: Department of Information Engineering, University of Padua, Padua, Italy.
authors: Francesca
authors: F
authors: Piccinini
authors: Department of Information Engineering, University of Padua, Padua, Italy.
authors: Chiara
authors: C
authors: Dalla Man
authors: Department of Information Engineering, University of Padua, Padua, Italy.
authors: Claudio
authors: C
authors: Cobelli
authors: Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors: Robert A
authors: RA
authors: Rizza
authors: Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors: Michael
authors: M
authors: Camilleri
authors: Division of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors: Adrian
authors: A
authors: Vella
keywords: endogenous glucose production; insulin action; insulin secretion; vagotomy