Statin treatment increases the sialic acid content of LDL in hypercholesterolemic patients

Low density lipoprotein (LDL) with low sialic acid content has been reported to cause intracellular cholesterol accumulation, and therefore desialylation has been proposed to be an atherogenic modification of LDL. However, it is not known whether hypolipidemic treatment has any effect on LDL sialylation. Accordingly, we investigated the sialic acid/apolipoprotein (apo) B ratio of total LDL and its subfractions in 26 moderately hypercholesterolemic patients at baseline and after treatment with statins for 2-3 months. Cholesterol and triglyceride levels were reduced in all apo B-containing lipoproteins, including all LDL subfractions, while the sialic acid ratio was increased in total LDL and in all its subfractions. Cholesterol concentrations and sialic acid ratios were inversely correlated in light and dense LDL subfractions both before and during statin treatment, and the greater the decrease in cholesterol and apo B contents of dense LDL, the higher was the increase in its sialic acid ratio. Furthermore, the lower the baseline sialic acid ratio of dense LDL, the greater was the reduction in its lipid and apo B concentrations. In conclusion, inhibition of cholesterol synthesis by statin treatment increased sialic acid/apo B ratio in LDL proportionately to the decrease of LDL apo B and cholesterol.