Hypothesis: The investigators hypothesize that the administration of metformin in obese CKD patients will significantly improve the adipokine profiles-particularly through a reduction in LAR. Additionally, that it will improve systemic inflammation, oxidative stress and endothelial function, which may or may not be mediated by changes in adipokines. Finally, the investigators hypothesize that improvements in these markers of vascular health will translate into reduced arterial stiffness and less clinical CV events