#2432 DNA damage analysis with oxidative stress index in patients developing contrast nephropathy after coronary angiography
Authors: Demirkiran Ozge , Kocaturk Evin , Demiryurek Bahar , Murat Selda , Tezcan Neslihan , Bal Cengiz , Mutluay Rüya 
Published: May 2024

Abstract

Background and Aims
Contrast Nephropathy (KN) is acute kidney injury that occurs after exposure to contrast material. Advanced age, chronic kidney disease, heart failure, anemia, hypertension, diabetes mellitus, and hyperuricemia have been reported in the literature to increase the risk of KN development. In addition, oxygen radicals have an important place in the pathogenesis of contrast nephropathy development. Specific biomarkers are used in clinics to determine oxidative stress and antioxidant status. In particular, measurement of total antioxidant status (TAS) and total oxidant status (TOS) can provide useful information about an individual's overall serum antioxidative status. The ratio of TOS to TAS level gives the oxidative stress index (OSI). One of the most investigated metabolites for DNA damage is 8-hydroxy-2-deoxyguanosine (8-OhdG), which is accepted as a biomarker of oxidative damage to DNA. In our study, we planned to investigate DNA damage and important predisposing factors for contrast nephropathy using oxidative stress markers.

Method
Between February 2021 and April 2022, blood was taken from 191 patients who underwent coronary angiography (CAG) by the Cardiology Department at ESOGU before CAG and at 72 hours after CAG. Patients who met the criteria for contrast nephropathy development (those with a serum creatinine increase of 25% or more compared to baseline or an increase of 0.5 mg/dl or more) were included as the case group in our study. Our study is a prospective study consisting of 85 cases and 106 controls, totaling 191 participants. TAS, TOS, OSI, and 8-OhDG levels were compared between both groups and before-after procedure. This study was supported by ESOGU BAP project number 1621.

Results
The mean age of the developing group was calculated as 68.13 ± 10.37, while it was calculated as 61.03 ± 9.97 in the control group (p = 0.00). In the case group, there were 30 (35.3%) without heart failure, while there were 75 (70.8%) without heart failure in the control group (p = 0.00). In univariate analyzes, we found that advanced age and heart failure were the most important indicators for KMN. When we compared those with and without KMN, we saw that TOS values decreased less in the group with post-angiography nephropathy than in those without it. We found a positive correlation between uric acid and TAS. In the KMN group, it was found that there was a statistically significant increase in TAS value after CAG, while there was a decrease in OSI value, and no statistically significant difference was found for TOS and 8-OhDG. In patients who underwent percutaneous intervention, it was found that there was a statistically significant increase in TAS value after CAG, while TOS and OSI decreased, and no significant difference was found for 8-OhDG.

Conclusion
Although previous studies have shown that oxidative stress plays an important role in contrast nephropathy pathogenesis, a strong relationship between KMN development and oxidative stress could not be found in our study. Our study is the first study to examine DNA damage with 8-OhDG in KMN, and it has been shown that there is no increase in DNA damage with KMN development. It is thought that one of the reasons leading to this result may be that contrast agents used today are selected as less toxic substances used in less volumes during processing, which may prevent DNA damage from occurring. Another result reached in our study is that TAS level increased in patients undergoing percutaneous intervention, while TOS and OSI decreased; that is, revascularization can reduce TOS and ultimately oxidative status.”