Comparison of Total Antioxidant Capacity in COPD, Asthma, and Asthma-COPD Overlap Patients

Background and Objectives: Asthma, COPD, and asthma-COPD overlap are obstructive lung diseases with inflammation at their core. Oxidative stress and impaired antioxidant balance play a significant role in etiopathogenesis. This study aimed to determine whether there are differences in total antioxidant capacity (TAC) between asthma, COPD, and asthma-COPD overlap. Materials and Methods: A total of 76 patients participated in this prospective cross-sectional study. TAC levels in fasting venous blood samples were measured using a biochemistry analyzer and the total antioxidant activity method (Architect C1600, Abbott Laboratories, IL, USA). Results: TAC levels were lower in COPD patients compared to asthma and ACO patients (p = 0.049 and 0.026, respectively). TAC levels were lower in current and former smokers compared to never smokers (p = 0.033). There was no significant correlation between TAC level and eosinophil count (p = 0.597) and FEV1 and FEV1/FVC (p = 0.372 and p = 0.189). Conclusions: Our results suggest that TAC levels may serve as a marker to differentiate COPD from asthma or ACO.