PPARgamma agonists and vascular risk factors: potential effects on cardiovascular disease.

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily comprising four subtypes designated PPARalpha, PPARgamma1, PPARgamma2, and PPARdelta. These are transcription factors that regulate gene expression, thereby controlling energy metabolism. PPARgamma has widespread distribution in the adipose tissue, skeletal muscle, heart, liver, kidney, gut, macrophages, and vascular tissues. PPARgamma has a key role in adipogenesis, insulin sensitivity, and glucose and lipid metabolism, and also plays a major role in vascular biology, modulating atherosclerosis progression and vascular endothelial function. Thiazolidinediones (TZDs) are the ligands of PPARgamma, and growing evidence suggests that they might both directly and indirectly influence cardiovascular risk in type 2 diabetes patients by favorably altering several pro-atherogenic metabolic processes.