Oxidized low-density lipoproteins, autoantibodies against oxidized low-density lipoproteins and carotid intima media thickness in a clinically healthy population

Background: Oxidized low-density lipoproteins (oxLDLs) play an important role in the progress of atherosclerosis. Autoantibodies (oxLDL Ab) against oxLDLs may reflect the extent of LDL oxidation in vivo. Our aim was to investigate the correlation between oxLDLs, oxLDL Ab and intima media thickness of the common carotid arteries (CCA-IMT) in a clinically healthy population. Methods: Two hundred subjects were recruited, and demographic and clinical characteristics of the subjects were recorded. By use of tertile classification of plasma oxLDLs and oxLDL Ab, 9 groups including 4 extreme subject groups were generated. CCA-IMT was measured as an indicator of carotid atherosclerosis. Results: Age and plasma LDL concentration contributed significantly to CCA-IMT (p < 0.05). Body mass index, smoking index and plasma LDL concentration were significantly positively related to the plasma oxLDLs concentration; by contrast, plasma oxLDL Ab were significantly negatively related to the plasma oxLDL concentration (p < 0.05). Subjects in the group with low oxLDL Ab/high oxLDLs had the greatest CCA-IMT and the highest level of LDL; by contrast, subjects in the group with high oxLDL Ab/low oxLDLs had the least CCA-IMT and the lowest level of LDL. Conclusions: Both plasma oxLDLs and oxLDL Ab contribute, although in opposite ways, to the LDL metabolism and development of atherosclerosis. Immune response to oxLDLs may exert a protective role at an early stage of atherosclerosis. Copyright (c) 2007 S. Karger AG, Basel.