The effects of glucose-dependent insulinotropic polypeptide infused at physiological concentrations in normal subjects and type 2 (non-insulin-dependent) diabetic patients on glucose tolerance and B-cell secretion.
The effects of porcine glucose-dependent insulinotropic polypeptide given by continuous intravenous infusion in normal subjects (n = 6) and Type 2 (non-insulin-dependent) diabetic patients (n = 6) have been investigated. The subjects were studied on 2 separate days after overnight fasts. On each day 25 g of glucose was infused from 0-30 min plus an infusion of either porcine glucose-dependent insulinotropic polypeptide (0.75 pmol . kg-1 . min-1) or control solution. During the glucose-dependent insulinotropic polypeptide infusion plasma glucose values were reduced in normal subjects from 30-60 min (p less than 0.01) and in Type 2 diabetic patients at 45 and 60 min (p less than 0.05). In the normal subjects insulin concentrations were greater from 10-35 min (p less than 0.01) following glucose-dependent insulinotropic polypeptide infusion and peak values were increased by 123%. In the Type 2 diabetic patients following glucose-dependent insulinotropic polypeptide infusion insulin levels were increased from 4-40 min (p less than 0.01) but peak values were only increased by 27%. In the normal subjects C-peptide values were greater from 25-45 min (p less than 0.01) following glucose-dependent insulinotropic polypeptide infusion and peak C-peptide levels were increased by 82%. In the Type 2 diabetic patients following the glucose-dependent insulinotropic polypeptide infusion C-peptide levels were increased from 6-55 min (p less than 0.01) and peak values were increased by 20%. Plasma glucose-dependent insulinotropic polypeptide levels were within the physiological post prandial range during the glucose-dependent insulinotropic polypeptide infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
Jones
I R
IR
Department of Medicine, University of Wales College of Medicine, Cardiff, UK.
Owens
D R
DR
Moody
A J
AJ
Luzio
S D
SD
Morris
T
T
Hayes
T M
TM
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000628:therapy*; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000008:administration & dosage* / Q000097:blood; D005951:Glucose Tolerance Test; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood*; D008297:Male
D001786:Blood Glucose; D007328:Insulin; D005749:Gastric Inhibitory Polypeptide