[LDL-cholesterol homogeneous assays versus Friedewald's equation].

Low-density lipoprotein (LDL) is an important risk factor for coronary artery disease as well as ischemic stroke. In clinical practice, LDL-cholesterol (LDL-C) is calculated by Friedewald's equation or determined by homogeneous assays for LDL-C. Although Friedewald's equation has some limitations, it has been widely used for LDL-C measurement for nearly 40 years. On the other hand, the first LDL-C homogeneous assay was developed in the late 1990s. New reagents have appeared on the market one after another, and 12 homogeneous assays are now available in Japan; however, they measure LDL-C by different principles, which are not disclosed to the public. There is some debate about which method is superior for LDL-C measurement of clinical samples.