Glucagon-Like Peptide-1 (7-37) Augments Insulin Release in Elderly Patients With Diabetes

Glucagon-like peptide-1 (GLP-1) is a potent stimulator of glucose-induced insulin release (1). Unlike glucose-dependent insulinotropic polypeptide (GIP), GLP-1 augments insulin release in middle-aged patients with type 2 diabetes (1) and is therefore a potentially promising agent for the treatment of type 2 diabetes. We undertook the following experiments to determine whether the effects of GLP-1 on glucose-induced insulin release are preserved in elderly patients with diabetes. These studies were conducted on 8 elderly patients with diabetes (age 77 ± 1 years, BMI 28 ± 1 kg/m2). The mean duration of diabetes was 8 ± 1 years and mean HbA1c was 7.1 ± 0.2%. All subjects were free of clinically apparent microvascular, macrovascular, or neuropathic complications. Patients with hypertension were not excluded. Three of the subjects were treated with sulfonylurea drugs, and four were being treated with angiotensin-converting enzyme inhibitors for hypertension. All medications were stopped at least 2 weeks before the test. This study was approved by the Committee on Human Investigation at the University of British Columbia. All subjects gave written informed consent before participation. Each subject underwent two hyperglycemic clamp studies in random order, separated by at least 4 weeks (2 …