Differential effects of gastric bypass and banding on circulating gut hormone and leptin levels.
OBJECTIVE
To quantify plasma concentrations of hormones that regulate energy homeostasis in order to establish possible mechanisms for greater weight loss after Roux-en-Y gastric bypass (RYGBP) compared with gastric banding (BND).


METHODS
Four groups of women were studied: lean (n = 8; mean BMI, 21.6 kg/m2); BND (n = 9; BMI, 35.8; 25% weight loss), RYGBP (n = 9; BMI, 34.2; 36% weight loss), and controls matched for BMI to the surgical groups (n = 11; BMI, 34.4).


RESULTS
Fasting total peptide YY (PYY) and PYY(3-36) immunoreactivity were similar among all groups, but the postprandial response in the RYGBP group was exaggerated, such that 30 minutes after the meal, total and PYY(3-36) levels were 2- to 4-fold greater compared with all other groups. Maximal postprandial suppression of total ghrelin was blunted in the BND group (13%) compared with RYGBP (27%). Postprandial suppression of octanoylated ghrelin was also less in BND (29%) compared with RYGBP (56%). Fasting insulin was lower in RYGBP (6.6 microU/mL) compared with BND (10.0 microU/mL). Compared with lean controls, leptin concentrations were significantly higher in BND but not in RYGBP. There was a greater increase in post-meal satiety in the RYGBP group compared with BND and overweight controls.


CONCLUSIONS
The differences between RYGBP and BND subjects in postprandial concentrations of PYY and ghrelin would be expected to promote increased satiety and earlier meal termination in RYGBP and may aid in greater weight loss. The differences in insulin and leptin concentrations associated with these procedures may also reflect differences in insulin sensitivity and energy partitioning.
Korner
Judith
J
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA. jk181@columbia.edu
Inabnet
William
W
Conwell
Irene M
IM
Taveras
Carmen
C
Daud
Amna
A
Olivero-Rivera
Lorraine
L
Restuccia
Nancy L
NL
Bessler
Marc
M
D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D005260:Female; D015390:Gastric Bypass; D015391:Gastroplasty; D054439:Ghrelin; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood*; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery*; D036361:Peptide Hormones / Q000097:blood; D019894:Peptide YY / Q000097:blood*; D019518:Postprandial Period; D012528:Satiety Response / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology
D054439:Ghrelin; D007328:Insulin; D020738:Leptin; D036361:Peptide Hormones; D019894:Peptide YY