Total antioxidant capacity as a marker in predicting severity of chronic obstructive pulmonary diseases

Abstract

Abstract Background The pathogenesis of chronic obstructive pulmonary disease (COPD) is multifactorial; oxidative stress is suggested to be one of the pathogenetic factors. Objective The aim of this study was to assess the role of antioxidant status in pathogenesis of COPD and in predicting the severity of airway obstruction. Patients and methods This case-controlled study was carried on 60 patients with COPD, and on 15 apparently healthy age-matched smokers and 15 apparently healthy age-matched nonsmokers, which served as control groups. Bronchoscopy with bronchoalveolar lavage was carried out for 10 COPD patients. Chest radiography, pulmonary function testing, and arterial blood gases were carried out for all groups. Serum level of total antioxidant (TAO) was also measured in all groups by using the enzyme-linked immunosorbent assay kit. Results Serum TAO level was significantly reduced in COPD patients and healthy smokers compared with healthy nonsmokers (P<0.001, respectively); moreover, serum TAO level was significantly reduced in COPD compared with healthy smokers (P<0.001), and serum TAO was significantly reduced in severe and very severe COPD compared with mild and moderate COPD (P=0.01 and 0.006, respectively). TAO level significantly negatively correlated with each of PaCO2 and HCO3 in COPD patients, and it was significantly positively correlated with each of forced expiratory volume in 1 s/forced vital capacity and forced expiratory volume in 1 s %. TAO had a sensitivity and specificity of 86.67 and 93.33, respectively, as a biomarker for identification and predicting the severity of COPD with an area under the curve of 0.921. Conclusion Serum TAO is a valuable biomarker in identifying and predicting the severity of COPD.

Keywords

• antioxidants
• chronic obstructive pulmonary disease
• pulmonary function tests