Association of the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio and concentrations of plasma lipids with high-density lipoprotein subclass distribution in the Chinese population

Small-sized preβ1-HDL, HDL3b and HDL3a increased significantly while large-sized HDL2a and HDL2b decreased significantly as the LDL-C/HDL-C ratio increased. The subjects in low HDL-C level (< 1.03 mmol/L) who had an elevation of the LDL-C/HDL-C ratio and a reduction of HDL2b/preβ1-HDL regardless of an undesirable or high LDL-C level. At desirable LDL-C levels (< 3.34 mmol/L), the HDL2b/preβ1-HDL ratio was 5.4 for the subjects with a high HDL-C concentration (≥ 1.55 mmol/L); however, at high LDL-C levels (≥ 3.36 mmol/L), the ratio of LDL-C/HDL-C was 2.8 in subjects, and an extremely low HDL2b/preβ1-HDL value although with high HDL-C concentration.With increase of the LDL-C/HDL-C ratio, there was a general shift toward smaller-sized HDL particles, which implied that the maturation process of HDL was blocked. High HDL-C concentrations can regulate the HDL subclass distribution at desirable and borderline LDL-C levels but cannot counteract the influence of high LDL-C levels on HDL subclass distribution.Lipid abnormalities have long been suspected to contribute to atherosclerosis (As); there is overwhelming evidence [1,2] that an elevated low-density lipoprotein cholesterol (LDL-C) concentration in plasma is atherogenic, whereas a higher high-density lipoprotein cholesterol (HDL-C) level is cardioprotective [2-4]. A series of studies suggested that the use of the ratio of LDL-C to HDL-C is superior to the use of HDL-C or LDL-C alone [5] and that the ratio of LDL-C/HDL-C may provide better risk assessment by concurrently accounting for both atherogenic and protective lipid fractions.The cardioprotective effect of HDL has been largely attributed to its role in reverse cholesterol transport (RCT), wherein excessive cholesterol is conveyed from peripheral tissues to the liver and steroidogenic organs. HDL encompasses a heterogeneous class of lipoproteins. Differences in the quantitative and qualitative content of lipids, apolipoproteins (apos), and enzymes result in the pres