Effect of variations in small intestinal glucose delivery on plasma glucose, insulin, and incretin hormones in healthy subjects and type 2 diabetes.
The determinants of postprandial blood glycemia are controversial. We assessed the effects of variations in the initial rate of small intestinal glucose delivery on blood glucose, plasma insulin, and incretin responses in both health and type 2 diabetes. Eight controls and eight patients with type 2 diabetes managed by diet alone underwent paired studies. On both days subjects received an intraduodenal glucose infusion (t = 0-120 min); on one day the infusion rate was variable, being more rapid initially (3 kcal/min) between t = 0 and 15 min and slower (0.71 kcal/min) subsequently (t = 15-120 min), whereas on the other day, the infusion rate was constant (1 kcal/min) from t = 0 to 120 min (i.e. on both days 120 kcal of glucose were administered). Between t = 0-180 min blood glucose, plasma insulin and plasma glucose-dependent insulin-releasing polypeptide were greater with the variable, compared with the constant, infusion. Between t = 0 and 30 min the magnitude of the rise in plasma glucagon-like peptide-1 was greater with the variable, compared with the constant infusion (P < 0.01, both groups). We conclude that modest variations in the initial rate of duodenal glucose entry may have profound effects on subsequent glycemic, insulin, and incretin responses.
O'Donovan
Deirdre G
DG
Department of Medicine, University of Adelaide, Royal Adelaide Hospital, North Terrace, Adelaide, SA 5000, Australia.
Doran
Selena
S
Feinle-Bisset
Christine
C
Jones
Karen L
KL
Meyer
James H
JH
Wishart
Judith M
JM
Morris
Howard A
HA
Horowitz
Michael
M
D001682:Biological Availability; D001786:Blood Glucose / Q000032:analysis*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy / Q000378:metabolism*; D004386:Duodenum; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000097:blood*; D005934:Glucagon / Q000097:blood*; D052216:Glucagon-Like Peptide 1; D005947:Glucose / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D007328:Insulin / Q000097:blood*; D007421:Intestine, Small / Q000378:metabolism*; D008875:Middle Aged; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*
D001786:Blood Glucose; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D005947:Glucose