title: Gastric emptying of orally administered glucose solutions and incretin hormone responses are unaffected by laparoscopic adjustable gastric banding.
abstract: BACKGROUND
  Laparoscopic adjustable gastric banding (LAGB) provides weight loss in obese individuals and is associated with improved glucose homeostasis and resolution of type 2 diabetes. However, in most available reports, potentially inappropriate methodology has been applied when measuring the impact of LAGB on glucose intolerance. In order to clarify the applicability of the diagnostic 75 g-oral glucose tolerance test (OGTT) to measure the effect of LAGB on glucose metabolism, we investigated the effect of LAGB on gastric emptying for liquids as well as pancreatic and incretin hormone responses.
  
  
  METHODS
  Eight obese patients (three with normal glucose tolerance, three with impaired glucose tolerance, and two with type 2 diabetes; age 47.5 ± 1.1 years (mean±SEM); body mass index 44 ± 1 kg/m²; HbA(1)c 6.2 ± 0.4%) underwent a 75 g-oral glucose tolerance test with 1 g acetaminophen before and ~6 weeks after LAGB.
  
  
  RESULTS
  A small weight reduction was seen after LAGB (125 ± 8 vs. 121 ± 8 kg, P = 0.014). No differences in determinants of gastric emptying were observed before and after LAGB (area under the serum acetaminophen curve 10.1 ± 0.6 vs. 9.8 ± 0.5 mM x 4 h, P = 0.8; peak acetaminophen concentration 62 ± 3 vs. 61 ± 3 μM, P = 0.8; acetaminophen peak time 98 ± 6 vs. 100 ± 6 min, P = 0.9). No differences in plasma glucose, insulin, C-peptide, glucagon, glucose-dependent insulinotropic polypeptide, or glucagon-like peptide-1 responses to the OGTT were observed before as compared to after LAGB.
  
  
  CONCLUSIONS
  OGTT can be used to evaluate glucose tolerance in obese patients before and after LAGB without bias from changes in gastric emptying. LAGB has no direct impact on incretin hormone secretion.
authors.affiliation: Department of Internal Medicine M, Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Lotte
authors.initials: L
authors.lastname: Usinger
authors.forename: Katrine B
authors.initials: KB
authors.lastname: Hansen
authors.forename: Viggo B
authors.initials: VB
authors.lastname: Kristiansen
authors.forename: Steen
authors.initials: S
authors.lastname: Larsen
authors.forename: Jens J
authors.initials: JJ
authors.lastname: Holst
authors.forename: Filip K
authors.initials: FK
authors.lastname: Knop
mesh_terms: D000082:Acetaminophen / Q000097:blood; D000328:Adult; D002096:C-Peptide / Q000097:blood; D005260:Female; D005746:Gastric Emptying; D005749:Gastric Inhibitory Polypeptide / Q000097:blood; D015391:Gastroplasty; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D018149:Glucose Intolerance / Q000175:diagnosis; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged
chemical_list: D002096:C-Peptide; D007328:Insulin; D000082:Acetaminophen; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1