Oxidized LDL and C-Reactive Protein Level in Relation to Carotid Intima-Media Thickness in Population with Risk Factors for Atherosclerosis

Introduction Elevated levels of oxidized LDL cholesterol (OxLDL)are considered to be a key factor of initiating and accelerating atherosclerosis. It promotes atherosclerosis through inflammatory and immunologic mechanisms that lead to the formation of macrophage foam cells. Objective To determine the relationship among OxLDL, C-reactive protein (CRP) level and carotid intima-media thickness (IMT) in population with risk factors for atherosclerosis. Methods The study group consisted of 125 clinically healthy, hypercholesterolaemic subjects (49.3 +/- 5.7 years; 75 females and 50 males) compared with 100 age-matched population-based control subjects. The study group was divided into two subgroups: subgroup A (the levels of LDL cholesterol > 5 mmol/L) and subgroup B (the levels of LDL cholesterol <5 mmol/L). None of the subjects had history of cerebrovascular, ischaemic heart disease, hypertension or diabetes mellitus. Lipid profiles were measured by enzymatic methods. OxLDL was measured by using a specific monoclonal antibody, mAb4E6. CRP was measured using hemiluminescent methods (Immulite - DPC). The common carotid IMT was measured by the B-mode ultrasound. Results Compared to controls, the study group had higher levels of OxLDL (119.97 +/- 43.15 vs. 82.03 +/- 25.99 IU/L; p<0.01) and CRP (6.20 +/- 3.55 vs. 2.68 +/- 3.04 mg/ml; p<0.05). IMT was significantly higher in study subjects (1.14 +/- 0.38 vs. 0.72 +/- 0.24 mm; p<0.05). We also found that, in the whole study group, IMT significantly positively correlated with OxLDL (r=0.442; p<0.05). We found that in the study subgroup A, IMT positively correlated with CRP (r=0.792; p<0.01). In controls, we found a significantly positive association between IMT and OxLDL (r=0.781; p<0.01) and CRIP (r=0.748; p<0.01). Conclusion The elevated levels of OxLDL and CRP are associated with higher common carotid intima-media thickness in population with risk factors for atherosclerosis.