Effects of fat on gastric emptying of and the glycemic, insulin, and incretin responses to a carbohydrate meal in type 2 diabetes.
BACKGROUND
Gastric emptying (GE) is a major determinant of postprandial glycemia. Because the presence of fat in the small intestine inhibits GE, ingestion of fat may attenuate the glycemic response to carbohydrate.


OBJECTIVE
The objective of this study was to evaluate the effect of patterns of fat consumption on GE and glucose, insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) concentrations after a carbohydrate meal in type 2 diabetes.


METHODS
This was a randomized, cross-over study in which GE of a radioisotopically labeled potato meal was measured on 3 d.


METHODS
The study was performed at the Royal Adelaide Hospital.


METHODS
Six males with type 2 diabetes were studied.


METHODS
Subjects ingested 1) 30 ml water 30 min before the mashed potato (water), 2) 30 ml olive oil 30 min before the mashed potato (oil), or 3) 30 ml water 30 min before the mashed potato meal that contained 30 ml olive oil (water and oil).


METHODS
GE, blood glucose, plasma insulin, GLP-1, and GIP concentrations were the main outcome measures.


RESULTS
GE was much slower with oil compared with both water (P < 0.0001) and water and oil (P < 0.05) and was slower after water and oil compared with water (P < 0.01). The postprandial rise in blood glucose was markedly delayed (P = 0.03), and peak glucose occurred later (P = 0.04) with oil compared with the two other meals. The rises in insulin and GIP were attenuated (P < 0.0001), whereas the GLP-1 response was greater (P = 0.0001), after oil.


CONCLUSIONS
Ingestion of fat before a carbohydrate meal markedly slows GE and attenuates the postprandial rises in glucose, insulin, and GIP, but stimulates GLP-1, in type 2 diabetes.
University of Adelaide, Department of Medicine, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000, Australia.
Diana
D
Gentilcore
Reawika
R
Chaikomin
Karen L
KL
Jones
Antonietta
A
Russo
Christine
C
Feinle-Bisset
Judith M
JM
Wishart
Christopher K
CK
Rayner
Michael
M
Horowitz
D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D005746:Gastric Emptying; D005749:Gastric Inhibitory Polypeptide / Q000097:blood*; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D007328:Insulin; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1