Glucagon-like peptide-1 (GLP-1), produced mainly in enteroendocrine cells, participates in energy homeostasis and glucose metabolism by regulating islet hormone secretion, gastrointestinal motility, and food intake, making GLP-1 agonist a treatment for diabetes and obesity. Pre-clinical and clinical studies have demonstrated that GLP-1 also has cardio-protection effects. GLP-1 agonists is able to improve markers of cardiac function, reduce myocardial infarct size and post-myocardial infarction remodeling in experimental myocardial infarction. And GLP-1 infusion improved left ventricular function and increases myocardial salvage in patients with acute myocardial infarction (AMI). The investigators' previous study found that GLP-1 analogues attenuated ischemia-reperfusion induced apoptosis of stem- and myocardial microvascular endothelial cells, and liraglutide (a GLP-1 analog) usage during hospital stay can prevent no-reflow and improve heart function in AMI. Therefore, the investigators carried out a cohort study to evaluate the association between plasma GLP-1 and in-hospital complications in patients with ST-segment elevation myocardial infarction.