The role of oxidative stress-related biomarkers in ascending aortic dilatation: malondialdehyde and paraoxonase-1 activity

Aim: This study aimed to evaluate the antioxidative and oxidative status of patients with ascending aortic dilatation using malondialdehyde, an oxidative stress marker, and paraoxonase-1 activity, an antioxidant enzyme.Methods: This cross-sectional study was conducted between August and December 2020. It included 56 consecutive patients (mean age 55.3 ± 8.6 years; range 31 to 67 years; 26 males, 30 females) with ascending aortic dilatation and 33 sex-and age-matched controls (mean age 54.5 ± 10.5 years; range 32 to 67 years; 13 males, 20 females) with normal aortic diameters. All participants were evaluated using transthoracic echocardiography. Malondialdehyde was analyzed using the thiobarbituric acid assay. Paraoxonase-1 activity was measured manually using a spectrophotometer. The relation of ascending aortic dilatation with malondialdehyde levels and paraoxonase-1 activity was identified with correlation analyses.Results: The patient group had significantly higher mean malondialdehyde than the control group (2.5 ± 1.9 μmoL/mL and 1.7 ± 0.3 μmoL/mL, respectively; p < 0.001). The patient group had significantly lower mean activity of paraoxonase-1 than the control group (18.5 ± 12.9 U/mL vs.30 ± 17.6 U/mL, respectively; p < 0.002). Serum malondialdehyde was negatively correlated with ascending aortic diameter (r = 0.293, p = 0.009). A significant negative correlation was found between the activity of serum paraoxonase-1 and ascending aortic diameter (r = -0.364, p = 0.001). Malondialdehyde levels and paraoxonase-1 activity were independent predictors of ascending aortic dilatation.Conclusion: The results are in line with the notion that increased malondialdehyde levels indicate lipid peroxidation, and decreased paraoxonase-1 activity indicates impaired antioxidant defense. Using them may help protect against the pathophysiology of ascending aortic dilatation.