Altered oxidant-antioxidant levels in the disease prognosis of chronic obstructive pulmonary disease

BACKGROUND It is well known that oxidant-antioxidant imbalance plays a key role in the pathophysiology of chronic obstructive pulmonary disease (COPD). OBJECTIVES To examine the role of altered levels of oxidant-antioxidants in disease severity of COPD and correlate it with the degree of airflow obstruction. METHODS We assessed malondialdehyde (MDA), total protein carbonyl and sulfhydryl levels in blood plasma and examined the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in erythrocytes. We also evaluated the level of total blood glutathione in whole blood and ferric ion reducing antioxidant power (FRAP) in plasma. RESULTS Levels of MDA (P < 0.001) and total protein carbonyls (P < 0.01) were significantly increased, while total protein sulfhydryl (P < 0.01) was decreased in COPD patients. We also observed decreased SOD (P < 0.05), GPx (P < 0.01) and catalase (P < 0.05) activity. FRAP (P < 0.001) in plasma was also decreased, whereas total blood glutathione was increased (P < 0.01). Correlations between oxidative stress and antioxidant markers with forced expiratory volume in 1 second (FEV1%) in COPD were negative with plasma TBARS and total blood glutathione, whereas a positive correlation was noticed with erythrocyte GPx and FRAP. CONCLUSION These results support the hypothesis that an oxidant-antioxidant imbalance, associated with oxidative stress in COPD patients, plays an important role in the progression of disease severity.