Objective: To study changes in the levels of systematic and airway local oxidative stress in patients in different stages of chronic obstructive pulmonary diseases (COPD), and explore the association between oxidative stress and glucocorticoid receptor (GR) level in the peripheral blood leukocytes.
Methods: The levels of malonaldehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) in induced sputum and plasma, as well as GR levels in peripheral blood leukocytes and plasma levels of cortisol and adrenocorticotrophic hormone (ACTH), were examined in 33 patients with acute exacerbations of COPD (AECOPD, group A), 27 with stable COPD (group B), and 28 healthy volunteers (including 15 smokers as group C, and 15 nonsmokers as group D).
Results: MDA level in induced sputum and plasma decreased, whereas the levels of GSH, SOD and GSH-PX increased significantly in the order of groups A, B, C, and D (P<0.05). The activity of SOD in induced sputum and plasma were significantly lower in group C than in group D. No significant difference was noted in the other oxidative stress indices between groups C and D (P>0.05). The plasma levels of cortisol and ACTH showed no significant difference between the 4 groups, while the GR level in peripheral blood leukocytes increased significantly in the order of groups A, B, C and D (1565-/+719, 2069-/+488, 2739-/+926, and 4793 -/+1415 U, respectively, P<0.05). After controlling for the factor of smoking status, the plasma and sputum SOD activity were both positively correlated to GR, with the partial correlation coefficient of 0.512 and 0.564, respectively (P<0.001).
Conclusion: Patients in different stages of COPD, especially those with AECOPD, may sustain systematic and local oxidation and anti-oxidation imbalance. Decreased SOD activity may contribute to GR level decrement in peripheral blood leukocytes in these patients.