Rapid gastric and intestinal transit is a major determinant of changes in blood glucose, intestinal hormones, glucose absorption and postprandial symptoms after gastric bypass.
OBJECTIVE
To evaluate the effect of modulating pouch emptying (PE) and SI transit of glucose after Roux-en-Y gastric bypass (RYGB) on blood glucose, incretin hormones, glucose absorption and gastrointestinal (GI) symptoms.


METHODS
Ten RYGB patients were studied twice in random order, receiving either a 150 ml glucose drink (200 kcal) or the same solution infused into the proximal Roux-limb at 4 kcal/min. Data were compared with 10 healthy volunteers who received a 4 kcal/min duodenal infusion. PE, cecal arrival time (CAT), blood glucose, plasma 3-O-methylglucose (3-OMG), insulin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-1 (GLP-1), and GI symptoms were measured.


RESULTS
In RYGB subjects, the glucose drink emptied very rapidly (PE t50 = 3 ± 1 min) and intestinal glucose infusion was associated with higher blood glucose and plasma 3-OMG, but lower plasma GLP-1, GIP, insulin, and GI symptoms than oral glucose (all P < 0.001), and comparable to volunteers. In RYGB subjects, CAT correlated inversely with peak GLP-1 (r = -0.73, P = 0.01), and plasma 3-OMG correlated tightly blood glucose (r = 0.94, P < 0.0001).


CONCLUSIONS
After RYGB, reducing intestinal glucose delivery to 4 kcal/min is associated with higher blood glucose, greater glucose absorption, lower incretin responses, and less GI symptoms, supporting rapid transit contribution to the exaggerated incretin responses and "dumping symptoms".
Department of Gastroenterology and Hepatology, Level 7, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia, 5000, Australia; Discipline of Medicine, University of Adelaide, Royal Adelaide Hospital, Level 6 Eleanor Harrold Building, North Terrace, Adelaide, South Australia, 5000, Australia.
Nam Q
NQ
Nguyen
Tamara L
TL
Debreceni
Jenna E
JE
Bambrick
Max
M
Bellon
Judith
J
Wishart
Scott
S
Standfield
Chris K
CK
Rayner
Michael
M
Horowitz
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D004377:Dumping Syndrome / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects / Q000534:rehabilitation; D005768:Gastrointestinal Hormones / Q000097:blood*; D005772:Gastrointestinal Transit / Q000502:physiology*; D005947:Glucose / Q000493:pharmacokinetics*; D006801:Humans; D007328:Insulin / Q000097:blood; D007408:Intestinal Absorption; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D013997:Time Factors
D001786:Blood Glucose; D005768:Gastrointestinal Hormones; D007328:Insulin; D005947:Glucose