Oxidation of LDL plays an important role in atherogenesis. The aim of our study was to determine the relation between ox-LDL, carotid intima-media thickness and other biochemical and clinical risk factors of atherosclerosis. We investigated 125 subjects, 64 patients with isolated hypercholesterolaemia, 30 with combined hyperlipidaemia, 31 subjects with normal plasma lipid levels. The study population was divided into two age-adjusted groups of 25 healthy controls and 34 patients with hyperlipidaemia. We measured plasma levels of ox-LDL, total cholesterol, TAG, LDL-cholesterol, HDL-cholesetrol, apo-A, apo-B, age, waist circumference, BMI and IMT. There was a correlation of ox-LDL with apo-B (r=0.733, p<0.0001), LDL-cholesterol (r=0.711, p<0.0001), total cholesterol (r=0.57, p<0.0001), age (r=0.475, p<0.0001), IMT (r=0.404, p<0.0001), TAG (r=0.252, p<0.005), waist circumference (r=0.238, p<0.007) and BMI (r=0.173, p=0.05). There was no correlation of ox-LDL with apo-AI and HDL-cholesterol.IMTcorrelated with age (r=0.706,p<0.0001), apo-B(r=0.447,p<0.0001),ox-LDL(r=0.404,p<0.0001), LDL-cholesterol (r=0.39, p<0.0001), total cholesterol (r=0.348, p<0.0001), waist circumference (r=0.326, p<0.0001), BMI (r=0.217, p<0.015) and TAG (r=0.2, p<0.025). There was no correlation between IMT and apo-AI, HDL-cholesterol. Comparing the two age-adjusted groups no significant differences in age, BMI, waist, apo-A and HDL-cholesterol were found. We observed significantly higher plasma levels of total cholesterol (7.2±1.08 vs. 4.813±0,84), LDL-cholesterol (4.566±1.14 vs. 2.79±0.79), TAG (2.434±1.31 vs. 1.032±0.44), apo-B (1.38±0.17 vs. 0.91±0.18), ox-LDL (76.26±26.93 vs. 52.15±15.32), ox-LDL/apo-B ratio (71.19±15.42 vs. 57.13±12.99), increased IMT (0.684±0.086 vs. 0.607±0.086) in patients with hyperlipoproteinaemia than in individuals with normal plasma lipid levels. In conclusion, elevated ox-LDL is associated with increased IMT. Ox-LDL may present useful marker of atherosclerosis.

        Key words: oxidized LDL, intima-media thickness, atherosclerosis, risk factors of atherosclerosis.