Serum Apolipoprotein J in Health, Coronary Heart Disease and Type 2 Diabetes Mellitus

Apolipoprotein (apo) J, clusterin, is ubiquitously expressed in many tissues, and is a component of high-density lipoproteins (HDLs). There is experimental evidence that it may be anti-atherogenic through its effects on cholesterol transport, smooth muscle cell proliferation and lipid peroxidation. HDLs containing apo J and apo A-I carry paraoxonase (PON1), which protects low-density lipoproteins from oxidative modification; however, the extent to which apo J affects coronary heart disease (CHD) is not known. We have developed a sandwich ELISA that enables apo J to be assayed in the range of 13-200 µg/mL. Serum apo J was 52.8±0.8 µg/mL (mean±SEM; range, 36.0-84.3 µg/mL; n=92) in healthy Japanese men, and 49.3±0.5 µg/mL (34.5-72.8; n=241) in healthy Japanese women. Multiple regression of these data and results from 67 men with CHD showed that apo J concentration was unrelated to age, sex or body mass index, but was positively related to serum PON1 (p