Variability in cholesteryl ester transfer protein in healthy Japanese hyper-HDL-cholesterolemic subjects

Hyper-high density lipoprotein (HDL)-cholesterolemia has been considered to be anti-atherogenic and is referred to as longevity syndrome. However, hyper-HDL-cholesterolemia induced by a cholesteryl ester transfer protein (CETP) deficiency may not be athero-protective, rather being atherogenic in nature. In a rural area in central Japan, the incidence of hyper-HDL-cholesterolemia has been found to be rather high (3.1% of healthy people). We studied healthy Japanese people in this area with hyper-HDL-cholesterolemia, particularly in relation to CETP.

Serum lipids were analyzed, and CETP mass was determined with an enzyme immunoassay method.

Blood was drawn after an overnight fast from 17 Japanese (5 males and 12 females) with serum HDL-cholesterol (C) > or =100 mg/dl.

Serum CETP mass in hyper-HDL-cholesterolemic subjects was distributed in a wide range. Serum CETP mass was positively correlated with low-density lipoprotein (LDL)-C, apolipoprotein (Apo) B, and LDL-C/HDL-C, with statistical significance. CETP was also positively correlated with LDL-C/Apo B.

These results suggest that hyper-HDL-cholesterolemia may not be a single clinical entity, but a mixture of various pathophysiological conditions, and that the ratio of LDL-C to HDL-C and the size of LDL may be important factors in classifying these conditions.