Associations between small dense LDL, HDL subfractions (HDL2, HDL3) and risk of atherosclerosis in Japanese-Americans.
ABSTRACT Small dense low-density lipoprotein (sdLDL) has been suggested to be more atherogenic than large buoyant LDL. High-density lipoprotein (HDL) consists of two major subfractions (HDL2, HDL3), and just as controversy remains regarding which of the two is the more powerful negative risk factor for atherosclerosis, associations between sdLDL and these HDL subfractions are unclear.
We measured sdLDL cholesterol (sdLDL-C), HDL2 cholesterol (HDL2-C) and HDL3 cholesterol (HDL3-C) by a newly developed method in 481 Japanese-Americans who were not using lipid-lowering medication, and examined the associations of these cholesterol concentrations with variables related to atherosclerosis.
In multivariate analysis, sdLDL-C was positively correlated with the body mass index (BMI), fasting glucose and insulin, 2-h glucose, HOMA-IR, high sensitivity C-reactive protein (hsCRP), and carotid artery intima-media thickness (IMT) after adjustment for age and sex. In particular, sdLDL-C was positively correlated with IMT, even after adjustment for sex, age, smoking status, hypertension, diabetes mellitus and hsCRP. HDL2-C was more closely inversely correlated than total HDL-C with BMI, fasting glucose and insulin, 2-h glucose, HOMA-IR, and hsCRP, whereas HDL3-C was not correlated with these factors. Additionally, HDL2-C was more closely correlated than total HDL-C or HDL3-C with sdLDL-C, LDL-C, triglycerides (TG), and apolipoprotein B (apoB).
SdLDL-C was closely associated with insulin resistance and glucose tolerance, lending credence to its potential as a useful risk marker in assessing carotid artery IMT and the present degree of atherosclerosis in Japanese-Americans. The findings also suggest that subjects with higher HDL2-C levels were better protected from atherosclerosis.
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ABSTRACT: Atherogenic dyslipidemia characterized by abnormal changes in plasma lipid profile such as low high-density lipoprotein (HDL) and increased triglyceride (TG) levels is strongly associated with atherosclerotic diseases. We aimed to evaluate the levels of pro- and antiatherogenic lipids and erythrocyte membrane cholesterol (EMC) content in normo- and dyslipidemic subjects to investigate whether EMC content could be a useful marker for clinical presentation of atherogenic dyslipidemia. Low-density lipoprotein (LDL), HDL and their subfraction levels and erythrocyte lipid content were determined in 64 normolipidemic (NLs), 42 hypercholesterolemic (HCs) and 42 mixed-type dyslipidemic subjects (MTDs). Plasma atherogenic lipid indices [small-dense LDL (sdLDL)/less-dense HDL (LHDL), TC/HDL-C, TG/HDL-C and Apo B/AI] were higher in MTDs compared to NLs (p < 0.001). The highest sdLDL level was observed in HCs (p < 0.01). Despite a slight increase in EMC level in dyslipidemic subgroups, the difference was not statistically significant. A significant negative correlation, however, was observed between EMC and sdLDL/LHDL in HCs (p < 0.035, r = -0.386). Receiver operating characteristic curves to predict sdLDL level showed that TG and EMC levels had higher area under curve values compared to other parameters in HCs. We showed that diameters of larger LDL and HDL particles tend to shift toward smaller values in MTDs. Our results suggest that EMC content and TG levels may be a useful predictor for sdLDL level in hypercholesterolemic patients.Journal of Membrane Biology 11/2013; · 2.48 Impact Factor