title: Hepatic and peripheral insulin sensitivity do not improve 2 weeks after bariatric surgery.
abstract: OBJECTIVE
  Bariatric surgery has rapid metabolic effects on glucose metabolism before the occurrence of clinically significant weight loss. This suggests an acute effect of the surgery itself, e.g., resulting from bypassing the nutrient flow from the proximal gastrointestinal tract. Rapid effects of Roux-en-Y gastric bypass surgery (RYGB) on glucose metabolism were defined.
  
  
  METHODS
  Glucose metabolism and total triglyceride hydrolysis in the basal state and during a hyperinsulinemic euglycemic clamp using stable isotopes 2 weeks were studied before and after RYGB.
  
  
  RESULTS
  Eighteen pre-menopausal women scheduled for RYGB were included. 2 weeks after RYGB median weight loss was 7.8 kg. Basal insulin and glucose levels decreased after surgery. Endogenous glucose production (EGP) was lower after surgery. In addition, insulin levels were lower during the clamp after surgery, suggesting enhanced clearance. Hepatic and peripheral insulin sensitivity did not change. Free fatty acid (FFA) levels increased after surgery both in the basal state and during the first step of the clamp. Total triglyceride hydrolysis did not change in the basal state and tended to be higher during hyperinsulinemia.
  
  
  CONCLUSIONS
  Within 2 weeks, RYGB reduces basal EGP as well as insulin and glucose levels without an acute beneficial effect on hepatic or peripheral insulin sensitivity. The latter may be explained by higher rates of lipolysis and exposure to FFA induced by the hypocaloric state.
authors.affiliation: Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. B.A.deWeijer@amc.uva.nl
authors.forename: B A
authors.initials: BA
authors.lastname: de Weijer
authors.forename: E
authors.initials: E
authors.lastname: Aarts
authors.forename: I M C
authors.initials: IM
authors.lastname: Janssen
authors.forename: F J
authors.initials: FJ
authors.lastname: Berends
authors.forename: A
authors.initials: A
authors.lastname: van de Laar
authors.forename: K
authors.initials: K
authors.lastname: Kaasjager
authors.forename: M T
authors.initials: MT
authors.lastname: Ackermans
authors.forename: E
authors.initials: E
authors.lastname: Fliers
authors.forename: M J
authors.initials: MJ
authors.lastname: Serlie
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005260:Female; D015390:Gastric Bypass; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008875:Middle Aged; D009765:Obesity / Q000601:surgery; D017697:Premenopause; D012146:Rest; D014280:Triglycerides / Q000378:metabolism; D015431:Weight Loss
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D014280:Triglycerides