Plasma Protein Lipofuscin-like Fluorophores in Men with Coronary Artery Disease Treated with Statins

Background

Lipid oxidation products react with protein to produce lipofuscin-like fluorophores (P-LLF) and modified apolipoprotein B that is an important element of the atherogenic properties of oxidized low-density lipoprotein (oxLDL). The aim of this study was to compare plasma concentrations of P-LLF between men with coronary artery disease (CAD) treated with statin drugs and healthy controls and to identify determinants of P-LLF.

Methods

Plasma markers of protein modification including P-LLF and oxidized low-density lipoprotein-4E6 (oxLDL-4E6), low-density lipoprotein-conjugated dienes (LDL-CD), lipid peroxides, apolipoprotein B, and serum albumin were measured in 24 men with CAD who were receiving statin therapy and 20 healthy men in the same age range.

Results

Plasma P-LLF (+23%, p = 0.001) was significantly higher and plasma oxLDL-4E6 (–33%, p <0.001) and apolipoprotein B (apoB) (–30%, p <0.001) concentrations were significantly lower in men with CAD compared with controls. Plasma P-LLF concentration was correlated significantly with plasma apoB (r = −0.596, p <0.001), serum albumin (r = 0.518, p <0.001), and age (r = 0.390, p = 0.009) and these variables were independent predictors of P-LLF in the study population. Plasma P-LLF was no longer significantly higher in men with CAD when plasma apoB concentration was taken into account.

Conclusions

Plasma P-LLF concentration is abnormally high and appears to be closely associated with lower levels of apoB in men with CAD receiving statin therapy. ApoB may be a preferential target of reactive aldehydic lipid oxidation products and a decrease in apoB may increase the quantity of these products available for condensation with albumin.

Key Words: Lipofuscin-like fluorophores, Oxidized LDL, Apolipoprotein B, Albumin, Oxidative stress, Coronary artery disease, Statins