Effects of Antioxidant Therapy on Lung Clearance, Pulmonary Function Tests and Oxidant Stress in Patients With Chronic Obstructive Pulmonary Disease

To investigate the effects of antioxidant therapy on pulmonary function tests (PFTs) and oxidant-antioxidant balance on COPD patients, pulmonary function tests (PFTs), arterial blood gas (ABG) analyses, alveolo-capillary permeability measurements and plasma levels of superoxide dismutase (SOD), malondial­dehyde (MDA), vitamin E, and vitamin C at the initiation of the study and after six weeks of antioxidant therapy were assessed in 13 patients with stable COPD. Significant changes were ob­served in the PFTs and ABG after therapy, while a slight but not significant decrease was noted in lung clearance with anti­oxidant therapy (p>0.05). MDA levels decreased from 7.7+0.8 to 6.1±0.29 nmol/mL (p:0.000) whereas SOD levels increased from 20.4±2.4 to 23.7+2.7 U/mL with therapy (p<0.001). Signi­ficant increases were observed in mean vitamin E (0.76.2 vs 0.82±7.2 mg%) (p:0.000) and vitamin C (4.3±0.2 vs 5.1+0.4 mg/dL) levels (p:0.000). Our findings indicate that antioxidant therapy as an adjunct to diet is effective on oxidant-antioxidant balance but has no demonstrable effects on PFTs and alveolo­capillary permeability.