Fibrates and future PPARalpha agonists in the treatment of cardiovascular disease

Abstract

Statins lower cardiovascular risk in patients with diabetes; however, as these patients are at higher risk than other cardiovascular patients, statins merely decrease coronary event rates to the level seen in untreated nondiabetic individuals at risk for cardiovascular disease, indicating the existence of substantial residual risk. One reasonable explanation resides in the fact that statins have only limited effectiveness on hypertriglyceridemia and low HDL cholesterol, and they do not normalize the LDL size-distribution pattern. Peroxisome proliferator-activated receptor (PPAR)alpha agonists, which include fibrates, normalize this atherogenic lipid profile, as well as several cardiovascular risk markers associated with the metabolic syndrome and type 2 diabetes. In particular, hypertriglyceridemia and the ratio of small dense:large buoyant LDL particles are significantly improved. Outcome trials of PPARalpha agonists have demonstrated reductions in cardiovascular morbidity in patients with diabetes and in those with the metabolic syndrome; plaque progression is diminished, diabetic nephropathy and retinopathy are counteracted and amputation-risk decreased. The combination of fibrates with statins improves overall lipoprotein profile further. PPARalpha agonists seem particularly indicated in patients with diabetes who have residual dyslipidemia (high triglyceride and/or low HDL) despite receiving statin therapy, and patients who are nondiabetic, overweight, insulin-resistant and who have hypertriglyceridemia and/or low HDL cholesterol and chronic inflammation.