GCG and obesity due to melanocortin 4 receptor deficiency: It is also worthy of interest the recent report demonstrating that three months of exenatide therapy had similar effects on microvascular endothelial function, markers of inflammation, oxidative stress, and vascular activation, as metformin, in patients with obesity and pre-diabetes [28], which could question the specific role of GLP-1 analogues in preserving endothelial function.