title: Obesity-associated intestinal insulin resistance is ameliorated after bariatric surgery.
abstract: OBJECTIVE
  The intestine is the main site for glucose absorption and it has been suggested that it exhibits insulin resistance. Bariatric surgery has been shown to reverse insulin resistance and type 2 diabetes, but its effects on human intestinal metabolism are unknown. Our aim was to evaluate the effects of insulin on intestinal glucose metabolism before and after bariatric surgery.
  
  
  METHODS
  Twenty-one morbidly obese individuals undergoing bariatric surgery and ten age-matched healthy individuals were recruited and intestinal and skeletal muscle glucose uptake (GU) was measured using [(18)F]fluoro-2-deoxyglucose and positron emission tomography at fast and during hyperinsulinaemia. MRI was used as anatomical reference. Obese participants were studied again 6 months postoperatively.
  
  
  RESULTS
  In contrast to healthy individuals, insulin had no effect on intestinal GU in obese participants with or without diabetes, suggesting that intestinal insulin resistance is present early in morbid obesity. Postoperatively, jejunal GU increased in line with whole-body and muscle GU. Postoperative GU values in the intestine correlated with whole-body insulin sensitivity, indicating that the intestinal mucosa may reflect the overall glycaemic state and potentially mediate obesity-associated insulin resistance.
  
  
  CONCLUSIONS
  This study shows that insulin is a potent stimulator of GU in the healthy intestine and that intestinal insulin resistance is ameliorated after bariatric surgery. In our study, obese individuals had intestinal insulin resistance regardless of their glycaemic status. Persistent changes in intestinal glucose metabolism are likely to influence both local processes in the gut and systemic glucose homeostasis.
authors: Turku PET Centre, University of Turku, PL 52, FIN-20520, Turku, Finland.
authors: Jaakko
authors: J
authors: Mäkinen
authors: Jarna C
authors: JC
authors: Hannukainen
authors: Anna
authors: A
authors: Karmi
authors: Heidi M
authors: HM
authors: Immonen
authors: Minna
authors: M
authors: Soinio
authors: Lassi
authors: L
authors: Nelimarkka
authors: Nina
authors: N
authors: Savisto
authors: Mika
authors: M
authors: Helmiö
authors: Jari
authors: J
authors: Ovaska
authors: Paulina
authors: P
authors: Salminen
authors: Patricia
authors: P
authors: Iozzo
authors: Pirjo
authors: P
authors: Nuutila
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery*; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology
chemical_list: D001786:Blood Glucose
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