Exaggerated glucagon-like peptide-1 and blunted glucose-dependent insulinotropic peptide secretion are associated with Roux-en-Y gastric bypass but not adjustable gastric banding.
BACKGROUND
The aim of this study was to measure the circulating levels of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and glucagon in patients who had undergone adjustable gastric banding (BND) or Roux-en-Y gastric bypass (RYGB) to understand the differences in glucose and insulin regulation after these procedures.


METHODS
This was a cross-sectional study of 3 groups of women matched for age and body mass index: group 1, overweight controls (n = 13); group 2, BND (n = 10); and group 3, RYGB (n = 13). Venous blood was drawn with the patient in the fasted state and throughout a 3-hour period after a liquid meal.


RESULTS
The fasting glucose level was similar between the 2 surgery groups; however, the fasting insulin concentrations were greater in the BND (10.0 microU/mL) than in the RYGB (6.2 microU/mL; P <0.05) group. The glucose level at 60 minutes was significantly lower in the RYGB group (70 mg/dL, range 38-82) than in the BND group (83 mg/dL, range 63-98). The GLP-1 levels at 30 minutes were more than threefold greater in the RYGB group (96 pmol/L) compared with the BND and overweight control (28 pmol/L) groups. The GLP-1 and insulin concentrations correlated at 30 minutes only in the RYGB group (r = .66; P = .013). The glucose-dependent insulinotropic peptide levels at 30 minutes were lower in the RYGB group (20 pmol/L) than in the BND group (31 pmol/L) or overweight control group (33 pmol/L). The peak glucagon levels were similar among the 3 groups.


CONCLUSIONS
Exaggerated postprandial GLP-1 and blunted glucose-dependent insulinotropic peptide secretion after RYGB might contribute to the greater weight loss and improved glucose homeostasis compared with BND.
Korner
Judith
J
Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA. jk181@columbia.edu
Bessler
Marc
M
Inabnet
William
W
Taveras
Carmen
C
Holst
Jens Juul
JJ
D000328:Adult; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D015390:Gastric Bypass; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism*; D015391:Gastroplasty; D005934:Glucagon / Q000378:metabolism; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009767:Obesity, Morbid / Q000378:metabolism* / Q000601:surgery*; D019518:Postprandial Period
D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D005934:Glucagon