Is Non-smoker COPD similar to Smoker COPD based on their oxidative damage?

<bold>Background:</bold> Chronic obstructive pulmonary disease (COPD), known to be a smoking-mediated disease, is highly prevalent among non-smokers in India. Oxidative stress remains a significant mechanism for COPD development. However, the pathophysiology of the disease in etiologically heterogenous non-smoker COPD remains relatively unexplored. <bold>Aim:</bold> To evaluate and compare the oxidative stress status in the serum of non-smokers COPD to that of smoker-COPD and ‘healthy’ subjects. <bold>Materials and methods:</bold> Consecutive COPD patients were recruited from our out-patient-department along with ‘healthy’ subjects (asymptomatic, normal spirometry & chest X-ray). The serum of all the subjects was isolated and used to measure the total oxidant status, total antioxidant status and oxidative stress index by Rel Assay kits following the manufacturer’s protocol. GraphPad Prism version-8 was used for statistical comparison among the groups. <bold>Results:</bold> Sixty COPD patients (30 smokers/ex-smokers and 30 non-smokers) were selected along with 29 normal subjects (12 smokers and 17 non-smokers) for comparison. The results revealed that non-smoker COPD patients have equally severe oxidative damage as compared to smoker COPD. The COPD (smoker and non-smoker) subjects have significantly higher (p <0.01) total oxidant status compared to the ‘healthy’ subgroup. Non-smoker COPD has significantly lower (p<0.05) total antioxidant status as compared to other groups. Oxidative stress index for smoker and non-smoker COPD were similar and they were significantly higher (p<0.01) than ‘healthy’ subjects. <bold>Conclusion:</bold> Oxidative stress plays a similar role in both non-smoker and smoker COPD subjects, but non-smoker COPD has a lower overall antioxidant activity.