DO disease stages affect oxidative stress in stable COPD?

Background: Detection of oxidative stress level may lead us to understand the pathogenesis of COPD better and to search for new treatments. Oxidative stress levels have also been shown to be elevated in stable COPD patients. We aimed to investigate whether the stage of COPD affects the severity of inflammation-induced oxidative stress in patients with stable COPD. Methods: Between June 2019 and March 2020, all consecutive patients admitted to COPD-specific outpatient clinics were included. Patients were classified A, B, and E according to the GOLD guideline. Results: The median age of 98 patients (Male: 92 (93.9 %)) was 65 (min-max: 49-86). A statistically significant difference was found between the groups in FEV1, FVC, and FEV1/FVC (p < 0.001). age, and thiols (r = -0.168, p = 0.049; r = -0.184, p = 0.035) and DS (r = -0.209, p = 0.019) were found to be negatively correlated at a low level. When adjusted for age, oxidative stress parameters were similar between stages. Conclusion: No difference between stages and oxidative stress parameters according to GOLD classification in stable COPD patients. Our results may be a guide for not using anti-inflammatory therapy except for attacks.