title: The gut hormone response following Roux-en-Y gastric bypass: cross-sectional and prospective study.
abstract: BACKGROUND
  Bariatric surgery is the most effective treatment option for obesity, and gut hormones are implicated in the reduction of appetite and weight after Roux-en-Y gastric bypass. Although there is increasing interest in the gut hormone changes after gastric bypass, the long-term changes have not been fully elucidated.
  
  
  METHODS
  Thirty-four participants were studied cross-sectionally at four different time points, pre-operatively (n = 17) and 12 (n = 6), 18 (n = 5) and 24 months (n = 6) after laparoscopic Roux-en-Y gastric bypass. Another group of patients (n = 6) were studied prospectively (18-24 months). All participants were given a standard 400 kcal meal after a 12-h fast, and plasma levels of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were correlated with changes in appetite over 3 h using visual analogue scores.
  
  
  RESULTS
  The post-operative groups at 12, 18 and 24 months had a higher post-prandial PYY response compared to pre-operative (p < 0.05). This finding was confirmed in the prospective study at 18 and 24 months. There was a trend for increasing GLP-1 response at 18 and 24 months, but this did not reach statistical significance (p = 0.189) in the prospective study. Satiety was significantly reduced in the post-operative groups at 12, 18 and 24 months compared to pre-operative levels (p < 0.05).
  
  
  CONCLUSIONS
  Roux-en-Y gastric bypass causes an enhanced gut hormone response and increased satiety following a meal. This response is sustained over a 24-month period and may partly explain why weight loss is maintained.
authors.affiliation: Department of Bariatric Surgery, Musgrove Park Hospital, Taunton, Somerset TA1 5DA, UK.
authors.forename: Dimitrios J
authors.initials: DJ
authors.lastname: Pournaras
authors.forename: Alan
authors.initials: A
authors.lastname: Osborne
authors.forename: Simon C
authors.initials: SC
authors.lastname: Hawkins
authors.forename: David
authors.initials: D
authors.lastname: Mahon
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Ghatei
authors.forename: Steve R
authors.initials: SR
authors.lastname: Bloom
authors.forename: Richard
authors.initials: R
authors.lastname: Welbourn
authors.forename: Carel W
authors.initials: CW
authors.lastname: le Roux
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D015390:Gastric Bypass; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery; D019894:Peptide YY / Q000097:blood*; D011184:Postoperative Period; D011446:Prospective Studies; D012528:Satiety Response / Q000502:physiology; D015431:Weight Loss / Q000502:physiology
chemical_list: D019894:Peptide YY; D052216:Glucagon-Like Peptide 1