Evaluation of the relationship of serum oxLDL and sLOX-1 levels with endothelial dysfunction in dyslipidemic individuals with different lipid content

Dyslipidemia is one of the most important risk factors for atherosclerotic cardiovascular disease (ASCVD). Oxidized low-density lipoprotein (oxLDL) is formed in the process of atherosclerosis. oxLDL is taken into the cell by scavenger receptors such as lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and foam cell is formed. Endothelial dysfunction results in increased endocan synthesis. This study was conducted to investigate the relationship between serum oxLDL and soluble LOX-1 (sLOX-1) levels and endocan in dyslipidemic individuals with different lipid content. The study group consisted of dyslipidemic (n=118) and normolipidemic (n=39) individuals. Serum samples obtained from blood samples taken after 12 hours of fasting were stored at -80 °C until use. The levels of oxLDL and its receptors sLOX-1 and CD36, inflammation markers interleukin-6 (IL-6), endocan and vascular cell adhesion molecule-1 (VCAM-1) levels associated with endothelial dysfunction were determined by enzymelinked immunosorbent assay (ELISA). In the dyslipidemic group and its subgroups: oxLDL, sLOX-1, CD36, IL-6, CRP, endocan and VCAM-1 parameters showed a significant increase (p<0.05). In dyslipidemic individuals, sLOX-1 showed a higher fold increase compared to CD36 more than healthy individuals. The product of the fold increase in oxLDL and sLOX-1 was used to evaluate the relationship with endothelial damage. In this parameter, a progressive increase was observed in the quartiles formed according to endocan in the other quartiles compared to the first quartile. The strongest correlation between parameters was observed in the total study group (n=157). In conclusion, the levels of oxLDL and its receptors were significantly increased in dyslipidemic individuals compared to healthy individuals and this change was closely associated with endothelial dysfunction. This relationship was more pronounced in combined hyperlipidemic individuals.