Abstract
Previous studies have suggested that glucagon-like peptide-1 (GLP-1) (7-36 amide) may have the direct effect of increasing insulin sensitivity in healthy man. To evaluate this hypothesis we infused GLP-1 in seven lean healthy men during a hyper insulinaemic (0.8 mU.kg-1.min-1), euglycaemic (5 mmol/l) clamp. Somatostatin (450 micrograms/h was infused to suppress endogenous insulin secretion, and growth hormone (3 ng.kg-1.min-1) and glucagon (0.8 ng.kg-1.min-1) were infused to maintain basal levels. GLP-1 (50 pmol.kg-1.h-1) or 154 mmol/l NaCl (placebo) was infused after 3 h of equilibration, i.e. from 180-360 min. GLP-1 infusion resulted in GLP-1 levels of approximately 40 pmol/l. Plasma glucose, insulin, growth hormone, and glucagon levels were similar throughout the clamps. The rate of glucose infusion required to maintain euglycaemia was similar with or without GLP-1 infusion (7.69 +/- 1.17 vs 7.76 +/- 0.95 mg kg-1.min-1 at 150-180 min and 8.56 +/- 1.13 vs 8.55 +/- 0.68 mg.kg-1.min-1 at 330-360 min) and there was no difference in isotopically determined hepatic glucose production rates (-0.30 +/- 0.23 vs -0.16 +/- 0.22 mg.kg-1.min-1 at 330-360 min). Furthermore, arteriovenous glucose differences across the forearm were similar with or without GLP-1 infusion (1.43 +/- 0.23 vs 1.8 +/- 0.29 mmol/l), (ANOVA; p > 0.60, in all instances). In conclusion, GLP-1 (7-36 amide) administered for 3 h, leading to circulating levels within the physiological range, does not affect insulin sensitivity in healthy man.
Original language | English |
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Journal | Diabetologia |
Volume | 39 |
Issue number | 10 |
Pages (from-to) | 1227-32 |
Number of pages | 6 |
ISSN | 0012-186X |
Publication status | Published - Oct 1996 |
Keywords
- 3-Hydroxybutyric Acid
- Adult
- Alanine/blood
- Analysis of Variance
- Blood Glucose/drug effects
- C-Peptide/blood
- Calorimetry, Indirect
- Fatty Acids, Nonesterified/blood
- Glucagon/blood
- Glucagon-Like Peptide 1
- Glucagon-Like Peptides
- Glucose Clamp Technique
- Humans
- Hydroxybutyrates/blood
- Infusions, Intravenous
- Insulin/blood
- Lactates/blood
- Male
- Neurotransmitter Agents/pharmacology
- Peptide Fragments/administration & dosage
- Reference Values
- Somatostatin/administration & dosage
- Time Factors