The effects of gastric surgery on systemic ghrelin levels in the morbidly obese.
OBJECTIVE
Circulating ghrelin, produced primarily in the stomach, is a powerful orexigen. Ghrelin levels are elevated in states of hunger, but rapidly decline postprandially. Early alterations in ghrelin levels in morbidly obese patients undergoing weight reduction surgery may be attributed to gastric partitioning.


METHODS
Thirty-four patients underwent Roux-en-Y gastric bypass with a completely divided gastroplasty to create a 15-mL vertically oriented gastric pouch. Eight other patients underwent other gastric procedures that did not involve complete division of the stomach, including 4 vertical banded gastroplasties and 4 antireflux surgical procedures. Six additional patients undergoing antireflux surgery served as lean control subjects. Plasma samples were obtained before surgery and immediately after surgery. In a substudy, plasma was collected after Roux-en-Y limb formation and after dividing the stomach to identify any changes in plasma ghrelin levels.


METHODS
Tertiary university medical center.


METHODS
Ghrelin levels at different stages of surgical intervention.


RESULTS
Mean +/- SEM preoperative and postoperative ghrelin levels in the gastric bypass group were 355 +/- 20 and 246 +/- 13 pg/mL, respectively (P<.001). In the vertical banded gastroplasty group and in all patients undergoing antireflux surgery, ghrelin levels were not significantly changed.


CONCLUSIONS
Compared with morbidly obese humans, lean controls had significantly higher plasma ghrelin levels at baseline. A divided gastroplasty creating a small proximal gastric pouch results in significant early declines in circulating ghrelin levels that are not observed with other gastric procedures. This may explain, in part, the loss of hunger sensation and rapid weight loss observed following gastric bypass surgery.
Lin
Edward
E
Section of Gastrointestinal and General Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, Ga. 30322, USA. Elin2@emory.edu
Gletsu
Nana
N
Fugate
Kim
K
McClusky
David
D
Gu
Li H
LH
Zhu
Juan-Li
JL
Ramshaw
Bruce J
BJ
Papanicolaou
Dimitris A
DA
Ziegler
Thomas R
TR
Smith
C Daniel
CD
D000328:Adult; D015390:Gastric Bypass; D005748:Gastric Fundus; D015391:Gastroplasty; D054439:Ghrelin; D006801:Humans; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery; D036361:Peptide Hormones / Q000097:blood*; D011184:Postoperative Period; D011446:Prospective Studies; D011863:Radioimmunoassay
D054439:Ghrelin; D036361:Peptide Hormones