Immunogenic lipid oxidation by oxidative stress in young people and the risk of early atherogenic endotelial dysfunction
Authors: Bezna M C , Pisoschi C , Bezna M , Danoiu S , Tudorascu I R , Ungureanu L M , Negroiu C E , Melinte P R 
Published: October 2022

Abstract

Introduction
The high presence of oxygen free radicals and low antioxidant enzymes values, trigger oxidative stress imbalance and lipid oxidation, with immunogenic potential, thus the occurrence of autoantibodies, with endothelial lesional effect, accelerating the onset of early atherogenesis. A high oxidative stress level in young people may also be involved in the development of non-lesional cardiac arrhythmias.

Purpose
Assessment of early atherogenic risk in young people with cardiac arrhythmias, with and without dyslipidemia, by determining oxidative stress profile, through specific antioxidant biomarkers (superoxide dismutase – SOD, glutathione peroxidase – GPx, and total antioxidant status – TAS), in relation to the development of lipid oxidation (oxidized low density lipoprotein – oxLDL) and autoantibodies anti-oxidized lipoprotein – anti-oxLDL), with a role in endothelial dysfunction.

Patients and methods
The research was conducted on 120 young subjects, 18–45 years old, divided into three equal groups: two groups (I, II) – subjects who presented non-lesional cardiac arrhythmic manifestations, 40 of them with dyslipidemia, 40 without dyslipidemia and a control group. SOD, GPx, TAS, as well as the lipid profile, oxLDL and anti-oxLDL antibodies were determined, in serum. Electrocardiogram and investigations were performed, in order to exclude a pre-existing cardiovascular pathology or conditions that may alter oxidative status and lipid profile.

Results
A decrease of antioxidant enzymes – SOD and GPx, as well as TAS was found, in patients with cardiac arrhythmias, with and without dyslipidemia. It was associated with an increased oxLDL level, as well as with the occurrence of anti-oxLDL autoantibodies. Compared to controls, both in arrhythmic patients with and without dyslipidemia, the mean values were reduced at 62–64% of the SOD activity, 68–74% of GPx and 52–54% of TAS, with increased mean values for oxLDL up to 206% in those with dyslipidemia and 161% in those without. OxLDL autoantibodies were also increased, 176% – 140%. Highly statistical correlations (p&lt;0.001) were found between decreased SOD, GPx, TAS and increased oxLDL and anti-oxLDLox autoantibodies. The decrease of oxidative stress biomarkers was also correlated with the presence of non-lesional cardiac arrhythmias.

Conclusions
1. Decreased antioxidant level is associated with accelerated lipid oxidation and the occurrence of anti-oxLDL autoantibodies. 2. Increased values of oxLDL and anti-oxLDL autoantibodies promote the onset of early endothelial lesions, triggering subclinical atherosclerosis.
3. The presence of oxidative stress associates the occurrence of non-lesional arrrhythmias in young people, as well as the risk of autoimmunity through anti-oxLDL antibodies. 4. Oxidized LDL increased to 206% and anti-oxLDL autoantibodies to 176% in both dyslipidemic and non-dyslipidemic patients, trigger a highly increased atherogenic risk.

Funding Acknowledgement
Type of funding sources: None.