title: Gut hormones as mediators of appetite and weight loss after Roux-en-Y gastric bypass.
abstract: OBJECTIVE
  To evaluate the physiologic importance of the satiety gut hormones.
  
  
  BACKGROUND
  Controversy surrounds the physiologic role of gut hormones in the control of appetite. Bariatric surgery remains 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.
  
  
  METHODS
  We correlated peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) changes within the first week after gastric bypass with changes in appetite. We also evaluated the gut hormone responses of patients with good or poor weight loss after gastric bypass. Finally, we inhibited the gut hormone responses in gastric bypass patients and then evaluated appetite and food intake.
  
  
  RESULTS
  Postprandial PYY and GLP-1 profiles start rising as early as 2 days after gastric bypass (P < 0.05). Changes in appetite are evident within days after gastric bypass surgery (P < 0.05), and unlike other operations, the reduced appetite continues. However, in patients with poor weight loss after gastric bypass associated with increased appetite, the postprandial PYY and GLP-1 responses are attenuated compared with patients with good weight loss (P < 0.05). Inhibiting gut hormone responses, including PYY and GLP-1 after gastric bypass, results in return of appetite and increased food intake (P < 0.05).
  
  
  CONCLUSIONS
  The attenuated appetite after gastric bypass is associated with elevated PYY and GLP-1 concentrations, and appetite returns when the release of gut hormones is inhibited. The results suggest a role for gut hormones in the mechanism of weight loss after gastric bypass and may have implications for the treatment of obesity.
authors.affiliation: Department of Metabolic Medicine, Hammersmith Hospital, Imperial College, London, United Kingdom.
authors.forename: Carel W
authors.initials: CW
authors.lastname: le Roux
authors.forename: Richard
authors.initials: R
authors.lastname: Welbourn
authors.forename: Malin
authors.initials: M
authors.lastname: Werling
authors.forename: Alan
authors.initials: A
authors.lastname: Osborne
authors.forename: Alexander
authors.initials: A
authors.lastname: Kokkinos
authors.forename: Anna
authors.initials: A
authors.lastname: Laurenius
authors.forename: Hans
authors.initials: H
authors.lastname: Lönroth
authors.forename: Lars
authors.initials: L
authors.lastname: Fändriks
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Ghatei
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Bloom
authors.forename: Torsten
authors.initials: T
authors.lastname: Olbers
mesh_terms: D001069:Appetite Regulation / Q000502:physiology*; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass; D054439:Ghrelin / Q000097:blood; 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*; D011446:Prospective Studies; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*
chemical_list: D054439:Ghrelin; D019894:Peptide YY; D052216:Glucagon-Like Peptide 1