Effect of niacin and atorvastatin on lipoprotein subclasses in patients with atherogenic dyslipidemia

This study was conducted to determine the efficacy of atorvastatin and niacin on lipoprotein subfractions in patients with atherogenic dyslipidemia. This was a multicenter, randomized, open-label, parallel-design study of patients with total cholesterol >200 mg/dl, triglycerides between 200 and 800 mg/dl, and apolipoprotein B >110 mg/dl. Patients were randomly assigned to atorvastatin 10 mg or immediate release niacin 3,000 mg daily for 12 weeks following a low-fat diet stabilization period. Lipoprotein subclasses were measured by nuclear magnetic resonance spectroscopy. Atorvastatin and niacin both significantly reduced the concentrations of very low-density lipoprotein (VLDL) particles (−31% and −29%, respectively) and small low-density lipoprotein (LDL) particles (−44% and −35%, respectively). Niacin increased the concentration of large LDL (+75%). Atrovastatin reduced the number of LDL particles more than niacin (31% vs 14%). In patients with atherogenic dyslipidemia, both drugs had important effects on lipoprotein subfractions, which contributed to a reduction in coronary heart disease risk. The drugs equally reduced VLDL subclass levels. Niacin shifted the LDL subclass distribution toward the larger particles, more effectively converted patients from LDL phenotype B to phenotype A, and increased levels of the larger and perhaps more cardioprotective high-density lipoprotein particles. In contrast, atorvastatin preferentially lowered the concentration of small LDL particles without increasing levels of large LDL, and more effectively, reduced LDL particle numbers. Atorvastatin had a preferred LDL effect, whereas niacin had a preferred high-density lipoprotein effect.