Effect of Ezetimibe/Atorvastatin Combination on Oxidized Low Density Lipoprotein Cholesterol in Patients With Coronary Artery Disease or Coronary Artery Disease Equivalent

Abstract

Ezetimibe is effective in providing additional low-density lipoprotein (LDL) cholesterol lowering when coadministered with statins, but its effect beyond LDL cholesterol lowering is unknown. Oxidized LDL (ox-LDL) is a better predictor of adverse cardiovascular events than standard lipid parameters. The objective of this study was to investigate the effect of ezetimibe on ox-LDL. A total of 100 patients with coronary artery disease or coronary artery disease equivalent were randomized to atorvastatin 40 mg/day and ezetimibe 10 mg/day or to atorvastatin 40 mg/day and placebo. LDL cholesterol, LDL cholesterol subfractions, and ox-LDL were measured at baseline and after 8 weeks of therapy. The ezetimibe group had a larger reduction in total LDL cholesterol compared to placebo. This was due mainly to a larger reduction in large buoyant LDL (24% vs 10%, p = 0.008). Ox-LDL level did not change in the placebo group (50 +/- 13 vs 51 +/- 13 U/L), while it decreased in the ezetimibe group, from 51 +/- 13 to 46 +/- 10 U/L (p = 0.01 vs baseline and p = 0.02 vs final level in placebo). The change in ox-LDL correlated significantly with those in total LDL and in large buoyant LDL (r = 0.6 and r = 0.5, respectively, p <0.01 for both), but not with that of small dense LDL, high-density lipoprotein, or very low density lipoprotein. In conclusion, this study demonstrates that ezetimibe decreases ox-LDL cholesterol through reductions in total LDL cholesterol and in large buoyant LDL cholesterol.