Are post-treatment low-density lipoprotein subclass pattern analyses potentially misleading?

• Main Authors: Hanson Mary E, Jensen Erin, Bird Steven, Leiter Lawrence A, Conard Scott, Bays Harold, Shah Arvind, Tershakovec Andrew M
• Format: Article
• Language: English
• Published: BMC 2010-11-01
• Series: Lipids in Health and Disease
• Online Access: http://www.lipidworld.com/content/9/1/136

<p>Abstract</p> <p>Background</p> <p>Some patients administered cholesterol-lowering therapies may experience an increase in the proportion of small LDL particles, which may be misinterpreted as a worsening of atherosclerotic coronary heart disease risk. This study assessed the lipid effects of adding ezetimibe to atorvastatin or doubling the atorvastatin dose on low-density lipoprotein cholesterol (LDL-C) levels (and the cholesterol content of LDL subclasses), LDL particle number (approximated by apolipoprotein B), and LDL particle size. This was a multicenter, double-blind, randomized, parallel-group study of hypercholesterolemic, high atherosclerotic coronary heart disease risk patients. After stabilization of atorvastatin 40 mg, 579 patients with LDL-C >70 mg/dL were randomized to 6 weeks of ezetimibe + atorvastatin 40 mg or atorvastatin 80 mg. Efficacy parameters included changes from baseline in LDL-C, apolipoprotein B, non-high-density lipoprotein cholesterol (non-HDL-C), and lipoprotein subclasses (Vertical Auto Profile II) and pattern for the overall population, as well as patient subgroups with baseline triglyceride levels <150 mg/dL or ≥150 mg/dL.</p> <p>Results</p> <p>Both treatments significantly reduced LDL-C (and the cholesterol content of most LDL subfractions [LDL_1-4]) apolipoprotein B, non-HDL-C levels, but did not reduce the proportion of smaller, more dense LDL particles; in fact, the proportion of Pattern B was numerically increased. Results were generally similar in patients with triglyceride levels <150 or ≥150 mg/dL.</p> <p>Conclusions</p> <p>When assessing the effects of escalating cholesterol-lowering therapy, effects upon Pattern B alone to assess coronary heart disease risk may be misleading when interpreted without considerations of other lipid effects, such as reductions in LDL-C, atherogenic lipoprotein particle concentration, and non-HDL-C levels.</p> <p>Trial Registration</p> <p>(Registered at clinicaltrials.gov: Clinical trial # NCT00276484)</p>