Research of total oxidant and antioxidant levels in autosomal dominant polycystic kidney's and its relationship with kidney functions

Aims: Autosomal dominant polycystic kidney disease (ADPKD) is a systemic, progressive disease characterized by renal and non-renal organs cysts, and is the most common inherited cause of end stage renal disease (ESRD). It is an important health problem with high mortality due to the lack of a permanent treatment and common cardiovascular complications. There are hypotheses that affect the severity and progression of the disease at the cellular level. "Oxidative stress", which is one of the predicted mechanisms, is defined as the disruption of oxidant-antioxidant balance in the body. The aim of our study is to measure total antioxidant level (TAS) and total oxidant level (TOS), to calculate the oxidative stress index (OSI) and to compare of these results with healthy volunteers. Thus, an idea about whether oxidative stress increases in the earlier stages of ADPKD, which is an important cause of hypertension (HT) and ESRD, can be obtained and precautions can be taken and a basis for determining new targets for treatment will be established. Materials and Methods:45 ADPKD (mean age 38 (39.9 ± 11.0)) and 45 healthy controls (mean age 41 (40.2 ± 11.3)) were included in the study. The mean estimated glomerular filtration (eGFR) of the study participants was preserved. TAS and TOS levels in serum were measured using the colorimetric Erel method in the participants who did not differ significantly in terms of age and eGFR. OSI was calculated (TOS / TAS * 100). The two groups were compared in terms of these parameters by nonparametric tests (Mann Whitney U). In addition, ADPKD group was evaluated in terms of differences within itself. The relationship between oxidative stress, presence of HT, nephrolithiasis, inflammation, kidney volume and drugs used were evaluated by correlation analysis. p <0.05 value was considered significant for statistical analysis. Results: There was no statistically significant difference between the two groups in terms of TAS, TOS and OSI levels. TOS and OSI levels were numerically higher in patients with ADPKD than healthy control group, they were not statistically significant (P> 0.05). No significant difference was found in ADPKD group in terms of oxidative stress and kidney volume, presence of HT, nephrolithiasis, use of renin- angiotensin aldosterone system inhibitor (RAASi). According to the correlation analysis in ADPKD group; TAS levels with Hb (r = 0.52 / p = 0.001), creatinine (r = 0.49 / p = 0.001), uric acid (r = 0.76 / p = 0.0001), ferritin (r = 0, 48 / p = 0.001) levels were significantly positively correlated. There was a significant negative correlation between serum urea (r = -0.32 / p = 0.034) and uric acid (r = -0.30 / p = 0.046) levels and OSI levels. According to the correlation analysis made in the healthy control group; the parameters showing significant positive correlation with TAS were age (r = 0.363 / p = 0.014), BMI (r = 0.420 / p = 0.004), systolic blood pressure (r = 0.523 / p = 0.000) and diastolic blood pressure (r = 0.304). / p = 0.042), Hb (r = 0.514 p = 0.000), creatinine (r = 0.443 / p = 0.002). The parameters showing significant negative correlation with TAS are eGFR (r = -0.372 / p = 0.012), ESR (r = -0.185 / p = 0.223), CRP (r = -0.295 / p = 0.049). It was shown that there was a significant positive correlation between BMI and TOS in the healthy control group (r = 0.323 / p = 0.031). Conclusion: Our study is the first study in which TAS, TOS, OSI levels and oxidative stress were investigated and compared with the healthy control group in early stage ADPKD, and the correlation of the results with other findings and patient characteristics was examined. There was no statistically significant difference in TAS, TOS, and OSI levels between patients with ADPKD with preserved renal functions and healthy control group. More clinical studies are needed in larger sample groups in order to reveal whether oxidative stress plays a role in the pathogenesis and progression of ADPKD by showing a cause and effect relationship. If the results are significant, it can be aimed to use TAS and TOS measurements, which reflect the entire oxidative balance, as a follow-up biomarker. In addition, having preventive treatment options that can be applied in the early stages of ADPKD may reduce overall cardiovascular events and mortality in individuals with potential ADPKD. The significant correlation results obtained in this study between oxidative stress markers and biochemical parameters may provide a basis for further studies to elucidate the mechanisms affecting the oxidant and antioxidant status in bioorganism.