Oxidative stress is thought to play a critical role in the pathogenesis of essential hypertension. Oxidized low-density lipoprotein (ox-LDL) has an important role during the atherosclerosis process and paraoxonase can significantly inhibit lipid peroxidation. We aimed to examine serum oxidized LDL, TNFa, LL-6 levels and paraoxonase (P0N1) activity as a biomarkers of oxidative stress in hypertensive patients. Thirty-eight hypertensive patients and twenty-two healthy control subjects were included in the study. Clinical assessment and blood pressure measurement were performed in patients. Serum Ox-LDL, TNF-a and LL-6 levels were measured by Enzyme-linked immunosorbent assay (ELLSA) method. P0N1 activities were measured by spectrophotometric method. Ox-LDL and LL-6 levels were significantly higher in hypertensive patients compared to controls ((p<0.01, p<0.01, respectively). P0N1 activities were found higher in dipper patients than those of non-dipper patients ((p<0.05). Increased OxLDL, LL-6 levels and decreased P0N1 activities in hypertensive patients might indicate increased oxidative stress, which plays an important role in the development of cardiovascular diseases. Dipper patients had mild signs of oxidative stress compared with non-dipper patients.

Keywords: Oxidized LDL, Paraoxonase, Inflammatory cytokines, Hypertension, Oxidative stress