Effect of atorvastatin on the concentration, relative distribution, and chemical composition of lipoprotein subfractions in patients with dyslipidemias of type IIA and IIB.

The authors investigated the effect of atorvastatin (40 mg qd) on low-density lipoprotein (LDL) particle distribution in patients with dyslipidemias of type IIA (n = 55) and IIB (n = 21). Atorvastatin therapy induced a significant decrease in total and LDL cholesterol in both patient groups. A significant reduction in triglyceride values, which was more profound in type IIB patients, was also observed. In type IIA patients, LDL-3 was the predominant subfraction. Atorvastatin therapy induced a significant reduction in total LDL mass in this group of patients that was mainly due to the reduction in large and intermediate subspecies (LDL-1 to LDL-3), whereas the mass of dense LDL particles (LDL-4 and LDL-5) remained unchanged. As a consequence, the percentage contribution of dense subfractions to the total LDL mass increased significantly after atorvastatin therapy. The dense LDL-4 subfraction was the predominant one in type IIB patients. In this group, atorvastatin therapy resulted in a significant reduction in the total LDL mass, which was due to the reduction in all LDL subfractions. Thus, the percentage mass distribution of LDL particles remained unaffected. These results suggest that the effect of atorvastatin on LDL subfractions is affected by the underlying genetic defect.