Lipoprotein subclasses-A changing landscape

The major classes of lipoproteins-low-density lipoprotein and high-density lipoprotein-are known to be heterogeneous in size, composition, and buoyant density and thus can be separated into subclasses. In recent years interest has increased in the use of lipoprotein subclasses in research and clinical laboratories as a means for assessing cardiovascular disease risk beyond conventional lipoprotein determination. This article reviews methods used in the determination of lipoprotein subclasses over the years, including ultracentrifugation, gradient gel electrophoresis, two-dimensional gel electrophoresis, and nuclear magnetic resonance spectroscopy. We also discuss the clinical utilities of such determinations and future directions of this area of research.