GCG and type 2 diabetes mellitus: There is some evidence from human studies that GLP-1 agonists might provide protection against heart failure: preliminary study [67] showed that GLP-1 treatment might have a trend towards improvement of cardiac function in type 2 diabetes patients with stable heart failure; intrinsic GLP-1 expression has been shown to compensatorily upregulate in patients with left heart failure [68]; and GLP-1 agonists are also shown to be associated with a modest increase of ejection fraction in diabetic patients [69].