Changes in apolipoprotein E-containing high-density lipoprotein (HDL) have little impact on HDL-cholesterol measurements using homogeneous assays in normolipidemic and dyslipidemic subjects.

Background: High-density lipoprotein-cholesterol (HDL-C) is generally measured using several homogeneous assays. We aimed to clarify whether apolipoprotein E-containing HDL (apoE-HDL) subfractions are altered during storage, and if so, whether such changes affect the HDL-C concentration measured using homogeneous assays.

Methods: We stored serum from normolipidemic (n=32) and dyslipidemic (n=17) subjects at 4°C for up to 7days.

Current smokers with hyperlipidemia lack elevated preβ1-high-density lipoprotein concentrations.

Background: Preβ1-high-density lipoprotein (HDL) is an efficient acceptor of cell-derived free cholesterol, which is converted into lipid-rich HDL by lecithin-cholesterol acyltransferase. Previous studies have shown that preβ1-HDL is significantly higher in individuals with hyperlipidemia. Preβ1-HDL concentrations may be altered in smokers, who are at high risk for atherosclerosis.