Metabolic Effects of Thiazolidinediones in Chronic Kidney Disease

The substantially increased cardiovascular morbidity and mortality rates in chronic kidney disease (CKD) patients cannot be sufficiently explained by traditional coronary risk factors. It is apparent that inflammation of the vessel wall plays an essential role in the pathophysiology of atherosclerosis, and the strong association between elevated inflammatory biomarkers and cardiovascular death further supports this mechanism. Approximately 50% of the mortality in this population of patients is attributable to cardiovascular disease. Insulin resistance is also a common problem in uremic patients. It has been shown that insulin resistance may contribute to atherosclerotic cardiovascular disease. An intriguing observation in CKD patients with advanced uremia is that the metabolic profile of these patients is characterized by persistent low-grade inflammation, a state of insulin resistance, and significantly increased prevalence of atherosclerosis. It is possible that these metabolic derangements can be the inciting factors for development and progression of uremic atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a ligand-activated nuclear transcription factor found in cells of the immune system and the vasculature, where it exerts an overall protective effect on the development of atherosclerosis, in part through modulation of inflammation. The agonists for PPAR-gamma improve not only the insulin resistance, but also have profound beneficial effects on inflammation, oxidative stress, endothelium, and lipid metabolism. In this proposal, the investigators hypothesize that short-term administration of a PPAR-gamma agonist (pioglitazone) will improve the inflammatory state, insulin resistance, and endothelial dysfunction in chronic kidney disease patients with advanced uremia.