Abstract
Context: The mechanism by which glucagon-like peptide-1 (GLP-1) suppresses glucagon secretion is uncertain, and it is not determined whether endogenous insulin is a necessary factor for this effect. Objective: To characterize the α- and β-cell responses to GLP-1 in type 1 diabetic patients without residual β-cell function. Methods: Nine type 1 diabetic patients, classified as C-peptide negative by a glucagon test, were clamped at plasma glucose of 20 mmol/liter for 90 min with arginine infusion at time 45 min and concomitant infusion of GLP-1 (1.2 pmol/kg · min) or saline. Results: Infusion with GLP-1 increased C-peptide concentration just above the detection limit of 33 pmol/liter in one patient, but C-peptide remained immeasurable in all other patients. In the eight remaining patients, total area under the curve of glucagon was significantly decreased with GLP-1 compared with saline: 485 ± 72 vs. 760 ± 97 pmol/liter · min (P < 0.001). In addition, GLP-1 decreased the arginine-stimulated glucagon release (incremental AUC of 103 ± 21 and 137 ± 16 pmol/liter · min, with GLP-1 and saline, respectively, P < 0.05). Conclusions: In type 1 diabetic patients without endogenous insulin secretion, GLP-1 decreases the glucagon secretion as well as the arginine-induced glucagon response during hyperglycemia. GLP-1 induced endogenous insulin secretion in one of nine type 1 diabetic patients previously classified as being without endogenous insulin secretion.
| Original language | English |
|---|---|
| Journal | Journal of Clinical Endocrinology and Metabolism |
| Volume | 95 |
| Issue number | 5 |
| Pages (from-to) | 2492-6 |
| Number of pages | 5 |
| ISSN | 0021-972X |
| DOIs | |
| Publication status | Published - May 2010 |
Keywords
- Arginine
- Blood Glucose
- C-Peptide
- Diabetes Mellitus, Type 1
- Glucagon
- Glucagon-Like Peptide 1
- Glucagon-Secreting Cells
- Humans
- Hyperglycemia
- Insulin-Secreting Cells
- Serum Albumin
