Rapid Effects Linagliptin on Monocyte Polarization and Endothelial Progenitor Cells in Type 2 Diabetes

Diabetes mellitus is characterized by chronic low grade inflammation, which is worsened by the co-existence of renal failure. One key aspect of chronic inflammatory diseases is the alteration in the polarization profile of circulating monocyte-macrophage cells. Namely, monocytes-macrophages can exist in a pro-inflammatory (M1) polarized form or an anti-inflammatory (M2) polarized state. Alterations in the M1/M2 balance is thought to contribute to inflammation within atherosclerotic lesions and visceral adipose tissue which, in turn, can worsen cardiovascular disease and metabolic features in type 2 diabetic patients. M1 and M2 are regulated by a complex interplay of soluble signaling molecules, many of which are substrate of the enzyme DPP-4 (dipeptidyl peptidase-4). Therefore, inhibition of DPP-4 can affect the M1/M2 polarization balance. In this clinical trial, the investigators will test whether the DPP-4 inhibitor Linagliptin, compared to placebo, modifies the M1/M2 balance in type 2 diabetic patients with and without chronic renal failure. In addition, we will test whether DPP-4 inhibition with Linagliptin acutely affects endothelial progenitor cells (EPCs), which are vasculoprotective cells implicated in the pathobiology of diabetic complications.