Increased oxidative stress in patients with chronic obstructive pulmonary disease (COPD) as measured by redox status of plasma coenzyme Q10

The plasma %CoQ-10 of COPD-Pt was 6.3 ± 2.3, significantly higher than that of CONTROL, 4.7 ± 1.6 (p < 0.05), indicating an increased oxidative stress in the patients. In contrast, no significant difference in %CoQ-10 was observed between young healthy non/slight smokers (%CoQ-10 = 3.2 ± 0.9) and young healthy smokers (%CoQ-10 = 3.7 ± 1.3). Our observation of five COPD patients who received an oxygen supplementation revealed that their %CoQ-10 values (4.0 ± 1.5) were significantly lower than those in COPD-Pt subjects (p < 0.05), suggesting that oxygen supplementation ameliorates the oxidative stress. In contrast, our study showed that no significant difference was observed among the three groups in plasma levels of Vitamin C or E. In conclusion, plasma %CoQ-10 levels are increased in COPD patients and oxygen supplementation attenuates this increasing effect by COPD. This implies that %CoQ-10 might be used practically to assess the COPD patients systemically.