Usefulness of the LDL-C/apoB ratio in the overall evaluation of atherogenicity of lipid profile.

Context: The ratio of low-density lipoprotein cholesterol to apolipoprotein-B (LDL-C/apoB) conventionally represents an alternative index of LDL particle size.

Objective: This study was undertaken to determine the importance of LDL-C/apoB ratio in the overall evaluation of atherogenicity of lipid profile.

Methods: The plasma levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) A-I, apoB and apoE were measured in 186 apparently healthy men using enzymatic and immunoturbidimetric methods.

Results: The subjects with low values of the LDL-C/apoB ratio, indicating a predominance of small dense LDL (sd-LDL) particles in plasma, were characterized by higher TG levels and lower apoE levels.

Conclusion: Low levels of apoE are most likely a cause of reduced clearance of TG-rich lipoproteins, which promotes the formation of sd-LDL. Determination of the LDL-C/apoB ratio can be used for monitoring qualitative changes in lipid profile, in addition to traditional lipid variables indicating quantitative changes.