Relation of Increased Prebeta-1 High-Density Lipoprotein Levels to Risk of Coronary Heart Disease

Pre beta-1 high-density lipoprotein (HDL) plays a key role in reverse cholesterol transport by promoting cholesterol efflux. Our aims were (1) to test previous associations between pre beta-1 HDL and coronary heart disease (CHD) and (2) to investigate whether pre beta-1 HDL levels also are associated with risk of myocardial infarction (MI). Plasma pre beta-1 HDL was measured by an ultrafiltration isotope dilution technique in 1,255 subjects recruited from the University of California-San Francisco Lipid and Cardiovascular Clinics and collaborating cardiologists. Pre beta-1 HDL was significantly and positively associated with CHD and MI even after adjustment for established risk factors. Inclusion of pre beta-1 HDL in a multivariable model for CHD led to a modest improvement in reclassification of subjects (net reclassification index 0.15, p = 0.01; integrated discrimination improvement 0.003, p = 0.2). In contrast, incorporation of pre beta-1 HDL into a risk model of MI alone significantly improved reclassification of subjects (net reclassification index 0.21, p = 0.008; integrated discrimination improvement 0.01, p = 0.02), suggesting that pre beta-1 HDL has more discriminatory power for MI than for CHD in our study population. In conclusion, these results confirm previous associations between pre beta-1 HDL and CHD in a large well-characterized clinical cohort. Also, this is the first study in which pre beta-1 HDL was identified as a novel and independent predictor of MI above and beyond traditional CHD risk factors. (C) 2011 Published by Elsevier Inc. (Am J Cardiol 2011;108: 360-366)