title: Gastric bypass does not normalize obesity-related changes in ghrelin profile and leads to higher acylated ghrelin fraction.
abstract: OBJECTIVE
  Gastric bypass (GBP) lowers food intake, body weight, and insulin resistance in severe obesity (SO). Ghrelin is a gastric orexigenic and adipogenic hormone contributing to modulate energy balance and insulin action. Total plasma ghrelin (T-Ghr) level is low and inversely related to body weight and insulin resistance in moderately obese patients, but these observations may not extend to the orexigenic acylated form (A-Ghr) whose plasma concentration increase in moderate obesity.
  
  
  METHODS
  We investigated the impact of GBP on plasma T-, A-, and A/T-Ghr in SO patients (n = 28, 20 women), with measurements at baseline and 1, 3, 6, and 12 months after surgery. Additional cross-sectional comparison was performed between nonobese, moderately obese, and SO individuals before GBP and at the end of the follow-up period.
  
  
  RESULTS
  Before GBP, SO had lowest T-Ghr and highest A/T-Ghr profile compared with both nonobese and moderately obese individuals. Lack of early (0-3 months from GBP) T-Ghr changes masked a sharp increase in A-Ghr and A/T-Ghr profile (P < 0.05) that remained elevated following later increments (6-12 months) of both T- and A-Ghr (P < 0.05). Levels of A-Ghr and A/T-Ghr at 12 months of follow-up remained higher than in matched moderately obese individuals not treated with surgery (P < 0.05).
  
  
  CONCLUSIONS
  The data show that following GBP, early T-Ghr stability masks elevation of A/T-Ghr, that is stabilized after later increments of both T- and A-hormones. GBP does not normalize the obesity-associated elevated A/T-Ghr ratio, instead resulting in enhanced A-Ghr excess. Excess A-Ghr is unlikely to contribute to, and might limit, the common GBP-induced declines of appetite, body weight, and insulin resistance.
authors.affiliation: Department of Medical, Surgical and Health Sciences, Internal Medicine Clinics, University of Trieste, Trieste, Italy. barazzon@units.it
authors.forename: Rocco
authors.initials: R
authors.lastname: Barazzoni
authors.forename: Michela
authors.initials: M
authors.lastname: Zanetti
authors.forename: Carlo
authors.initials: C
authors.lastname: Nagliati
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Cattin
authors.forename: Clara
authors.initials: C
authors.lastname: Ferreira
authors.forename: Michela
authors.initials: M
authors.lastname: Giuricin
authors.forename: Silvia
authors.initials: S
authors.lastname: Palmisano
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Edalucci
authors.forename: Franca
authors.initials: F
authors.lastname: Dore
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Guarnieri
authors.forename: Nicolò
authors.initials: N
authors.lastname: de Manzini
mesh_terms: D000215:Acylation; D000328:Adult; D001786:Blood Glucose; D015992:Body Mass Index; D001835:Body Weight; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000379:methods*; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000601:surgery*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D054439:Ghrelin; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol