[Current Status and Future of Lipid Examination in the Prevention and Clinical Treatment of Atherosclerotic Diseases--Chairmen's Introductory Remarks].

Measures against atherosclerotic diseases, accounting for one-third of the causes of death in the Japanese population, are critical for increasing human healthy life expectancy. In Japan, guidelines for the prevention of atherosclerotic cardiovascular diseases in 2012 and a dyslipidemia therapy guide were published by the Japan Atherosclerosis Society, and an outline of the clinical laboratory field, including serum lipid measurements, was also described in guidelines of the Japanese Society of Laboratory Medicine in 2012. Calculation using the Friedewald formula is recommended for LDL-cholesterol measurement, but the calculated LDL cholesterol values are not applicable in samples that are postprandial or with serum triglyceride (TG) levels of more than 400 mg/dL, and, if this is the case, non-HDL cholesterol (total cholesterol minus HDL cholesterol) should be evaluated. Such descriptions of LDL-cholesterol in these guidelines may be attributed to problems of homogenous LDL cholesterol assay reagents, including insufficient standardization and dispersion of LDL cholesterol values using a variety of reagents. Their accuracies have been questioned, especially in diseased subjects from the report of a joint U.S.-Japan study (Clin Chem 2010; 56: 977-86), and, subsequently, Miida T and Yoshida H et al. reported that the LDL-cholesterol homogenous assay agrees with the LDL cholesterol reference method (BQ) in non-diseased subjects, but exhibits positive bias for subjects with hypertriglyceridemia in diseased subjects with some reagents (Atherosclerosis 2012; 225: 208-15). Future improvements and advanced standardization of the LDL cholesterol homogenous assay are expected to greatly improve the credibility of serum lipid testing for the prevention and clinical treatment of atherosclerotic cardiovascular diseases.