“Normalization of Fasting Hyperglycemia by Exogenous Glucagon-Like Peptide 1 (7-36 Amide) in Type 2 (non-Insulin-Dependent) Diabetic Patients”, 1993-08 (; backlinks):
Glucagon-like peptide 1 (GLP-1) (7-36 amide) is a physiological incretin hormone that is released after nutrient intake from the lower gut and stimulates insulin secretion at elevated plasma glucose concentrations. Previous work has shown that even in Type 2 (non-insulin-dependent) diabetic patients GLP-1 (7-36 amide) retains much of its insulinotropic action. However, it is not known whether the magnitude of this response is sufficient to normalize plasma glucose in Type 2 diabetic patients with poor metabolic control.
Therefore, in 10 Type 2 diabetic patients with unsatisfactory metabolic control (HbA1c 11.6±1.7%) on diet and sulphonylurea therapy (in some patients supplemented by metformin or acarbose), 1.2 pmol ×kg−1×min−1 GLP-1 (7-36 amide) or placebo was infused intravenously in the fasting state (plasma glucose 13.1±0.6 mmol/l).
In all patients, insulin (by 17.4±4.7 nmol × 1−1 × min; p = 0.0157) and C-peptide (by 228.0±39.1 nmol × 1−1 × min; p = 0.0019) increased statistically-significantly over basal levels, glucagon was reduced (by −1418±308 pmol × 1−1 × min) and plasma glucose reached normal fasting concentrations (4.9±0.3 mmol/l) within 4h of GLP-1 (7-36 amide) administration, but not with placebo.
When normal fasting plasma glucose concentrations were reached insulin returned towards basal levels and plasma glucose concentrations remained stable despite the ongoing infusion of GLP-1 (7-36 amide). Therefore, exogenous GLP-1 (7-36 amide) is an effective means of normalizing fasting plasma glucose concentrations in poorly-controlled Type 2 diabetic patients. The glucose-dependence of insulinotropic actions of GLP-1 (7-36 amide) appears to be retained in such patients.
[Keywords: Type 2 (non-insulin-dependent) diabetes mellitus, incretin hormones, glucagon-like peptide 1 (7-36 amide), pancreatic glucagon, enteroinsular axis.]