Abstract
Context: Glucagon-like peptide-1 (GLP-1) and GLP-1 receptor agonists provide beneficial cardiovascular effects by protecting against ischemia and reperfusion injury. Type 2 diabetes mellitus patients have reduced glycolysis in the heart. Objective: We hypothesized that cardioprotection by GLP-1 is achieved through increased glucose availability and utilization and aimed to assess the effect of exenatide, a synthetic GLP-1 receptor agonist, on myocardial glucose uptake (MGU), myocardial glucose transport, and myocardial blood flow (MBF). Design and Methods: We conducted a randomized, double-blinded, placebo-controlled crossover study in eight male, insulin-naive, type 2 diabetes mellitus patients without coronary artery disease. Positron emission tomography was used to determine the effect of exenatide on MGU and MBF during a pituitary-pancreatic hyperglycemic clamp with 18F-fluorodeoxyglucose and 13N-ammonia as tracers. Results: Overall, exenatide did not alter MGU. However, regression analysis revealed that exenatide altered initial clearance of glucose over the membrane of cardiomyocytes and MGU, depending on the level of insulin resistance (P±0.017 and 0.010, respectively). Exenatide increased MBF from 0.73 ± 0.094 to 0.85 ± 0.091 ml/g ± min (P ± 0.0056). Except for an increase in C-peptide levels, no differences in circulating hormones or metabolites were found. Conclusions: The action of exenatide as an activator or inhibitor of the glucose transport and glucose uptake in cardiomyocytes is dependentonbaseline activity of glucose transport and insulin resistance. Exenatide increases MBF without changing MGU.
Original language | English |
---|---|
Journal | The Journal of clinical endocrinology and metabolism |
Volume | 97 |
Issue number | 7 |
Pages (from-to) | E1165-9 |
Number of pages | 5 |
ISSN | 0021-972X |
DOIs | |
Publication status | Published - Jul 2012 |
Keywords
- Biological Transport
- Coronary Circulation
- Cross-Over Studies
- Diabetes Mellitus, Type 2
- Double-Blind Method
- Glucose
- Heart
- Humans
- Hypoglycemic Agents
- Insulin Resistance
- Male
- Middle Aged
- Myocardium
- Peptides
- Placebos
- Positron-Emission Tomography
- Regional Blood Flow
- Up-Regulation
- Venoms