GCG and type 2 diabetes mellitus: BD indicates twice daily; CO, cardiac output; GLP, glucagon-like peptide-1; HF, heart failure; MP, myocardial perfusion; MBF, myocardial blood flow; MGU, myocardial glucose uptake; MVO2, myocardial oxygen consumption; NYHA, new York heat association; OD, once daily; SV, stroke volume; T2D, type 2 diabetes.