Objective: To compare the effects of simvastatin alone versus simvastatin plus ezetimibe on small dense low-density lipoprotein cholesterol (sdLDL-C) concentration in subjects with primary hypercholesterolemia.
Research design and methods: Patients with LDL-C levels above those recommended by the National Cholesterol Education Program Adult Treatment Panel III were randomized to open-label simvastatin 40 mg (n = 50) or simvastatin/ezetimibe 10/10 mg as a fixed combination (n = 50) daily. LDL particle size (estimated by electrophoresis), sdLDL-C levels, and lipid profile were blindly assessed at baseline and 3 months.
Clinical trial registration: clinicaltrials.gov NCT00932620.
Results: Both simvastatin 40 mg and simvastatin/ezetimibe 10/10 mg decreased total cholesterol (-31% and -36%, respectively), LDL-C (-43% and -49%, respectively), triglycerides (-17% and -19%, respectively), non-high-density lipoprotein cholesterol (non-HDL-C; -40% and -46%, respectively), large LDL-C (-40 and -44%, respectively) and sdLDL-C levels (-42% and -46%, respectively, all p < 0.000 vs baseline) and increased LDL particle size (+0.5% and +0.7%, respectively, both p < 0.05 vs baseline). The changes in total cholesterol, LDL-C and non-HDL-C were greater in the simvastatin/ezetimibe group (all p < 0.05). Changes in triglycerides, large LDL-C, sdLDL-C levels and LDL particle size were similar in the two groups. In multivariate analysis, baseline sdLDL-C and triglyceride levels, but not the choice of treatment, were significantly and independently correlated with the changes in sdLDL-C levels.
Conclusion: The combination of simvastatin 10 mg plus ezetimibe 10 mg is similarly effective to simvastatin 40 mg in improving sdLDL-C concentration and LDL particle size in subjects with primary hypercholesterolemia.