Atherosclerosis and cardiovascular risk reduction with PPAR agonists.

Peroxisome proliferator-activated receptors (PPARs) are transcriptional factors belonging to the nuclear receptor superfamily. Three isoforms, PPARalpha, PPARgamma, and PPARdelta, which are encoded by separate genes, have been identified. The PPARs act as gene regulators of various metabolic pathways in energy and lipid metabolism, glucose homeostasis, adipogenesis, and inflammation. Two key classes of synthetic compounds, fibrates and thiazolidinediones (glitazones), activate PPARalpha and PPARgamma, respectively. Both of these drugs have several properties that prevent atherosclerosis in the vascular wall and reduce the levels of risk factors for cardiovascular disease. However, clinical trials have not produced convincing evidence that cardiovascular disease is prevented with the use of PPARalpha and PPARgamma agonists.