GCG and endothelial dysfunction: Otherwise, sitagliptin can effectively alleviate inflammation-related endothelial dysfunction and fibrosis in heart failure model rats by reducing cardiac DPP4 activity, increasing the expression of circulating glucagon-like peptide-1 (GLP-1) and myocardial GLP-1 receptors, and decreasing the level of pro-inflammatory cytokine C–C motif chemokine ligand 2 (CCL2) [16].