title: Effect of weight loss by diet or gastric bypass surgery on peptide YY3-36 levels.
abstract: OBJECTIVE
  To examine the effect of an equivalent weight loss, by gastric bypass surgery (GBP) or by diet, on peptide YY3-36 (PYY3-36), ghrelin, and leptin levels and to determine the effect of diabetes status on PYY3-36 levels.
  
  
  BACKGROUND
  The increased PYY3-36 levels after GBP may be involved in the magnitude and the sustainability of weight loss after surgery.
  
  
  METHODS
  Of the 30 morbidly obese women who participated in the study, 21 had type 2 diabetes mellitus, and were studied before and after equivalent weight loss of 10 kg by either GBP (n = 11) or by diet (n = 10).
  
  
  RESULTS
  : PYY3-36 levels were higher in obese diabetic as compared with nondiabetic individuals (64.1 +/- 34.4 pg/mL vs. 39.9 +/- 21.1 pg/mL; P < 0.05). PYY3-36 levels increased markedly in response to oral glucose after GBP (peak: 72.3 +/- 20.5 pg/mL-132.7 +/- 49.7 pg/mL; P < 0.001; AUC0-180: 51.5 +/- 23.3 pg/mL x min-91.1 +/- 32.2 pg/mL x min P < 0.001), but not after diet (peak: 85.5 +/- 51.9 pg/mL-84.8 +/- 41.13 pg/mL; P = NS; AUC0-180: 68.3 +/- 38.5 pg/mL x min-61.1 +/- 42.2 pg/mL.min P = NS). Fasting ghrelin levels increased after diet (425 +/- 91 pg/mL-519 +/- 105 pg/mL; P < 0.05), but did not change after GBP (506 +/- 121 pg/mL-482 +/- 196 pg/mL; P = NS).
  
  
  CONCLUSIONS
  Diabetes status seems to be a determinant of PYY3-36 levels. GBP, but not diet-induced weight loss, resulted in markedly increased glucose-stimulated PYY3-36 levels. The increase in stimulated PYY3-36 levels after GBP is likely a result of the surgery rather than a secondary outcome of weight loss. Changes in PYY3-36 levels and ghrelin could contribute to the success of GBP in sustaining weight loss.
authors.affiliation: Obesity Research Center, St Luke's-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, NY, USA.
authors.forename: Blanca
authors.initials: B
authors.lastname: Oliván
authors.forename: Julio
authors.initials: J
authors.lastname: Teixeira
authors.forename: Mousumi
authors.initials: M
authors.lastname: Bose
authors.forename: Baani
authors.initials: B
authors.lastname: Bawa
authors.forename: Tangel
authors.initials: T
authors.lastname: Chang
authors.forename: Heather
authors.initials: H
authors.lastname: Summe
authors.forename: Hongchan
authors.initials: H
authors.lastname: Lee
authors.forename: Blandine
authors.initials: B
authors.lastname: Laferrère
mesh_terms: D000328:Adult; D015992:Body Mass Index; D031204:Caloric Restriction; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D005260:Female; D015390:Gastric Bypass; D054439:Ghrelin / Q000097:blood; D006801:Humans; D020738:Leptin / Q000097:blood; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000150:complications / Q000628:therapy*; D010446:Peptide Fragments; D019894:Peptide YY / Q000097:blood*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D054439:Ghrelin; D020738:Leptin; D010446:Peptide Fragments; D019894:Peptide YY; C061785:peptide YY (3-36)