Study of Correlation of Pulmonary Function Test with the Markers of Oxidative Stress and Non-enzymatic Antioxidants in Chronic Obstructive Pulmonary Disease (COPD) Patients

Abstract

Aims: Chronic Obstructive Pulmonary Disease (COPD) represents a major health problem. Its prevalence is increasing worldwide. The aim of our study was to assess the relationship between markers of oxidative stress (malondialdehyde (MDA) and protein carbonyl) and the non-enzymatic antioxidants (vitamin E, vitamin C and reduced glutathione (GSH) with the marker of airflow obstruction (FEV1% predicted) in COPD patients. Study Design: Case-control study. Place and Duration of Study: Department of Biochemistry, B.J. Govt. Medical College and Sassoon General Hospital, Pune. [Maharashtra]. The study period was in between Feb 2012 to Aug 2013. Methodology: Study comprised of 120 stable COPD patients of different stages were selected as per (GOLD) guidelines, each group consisting 30 patients, of age 40-75 yrs and 30 healthy controls. Pulmonary function test was done by using spirometer. Serum levels of MDA, protein carbonyl, vitamin E, vitamin C and GSH were estimated by spectrophotometric method. Statistical analysis was performed by using SPSS 17 software. Results: Lung function tests namely FEV1/FVC% ratio and FEV1 % predicted showed significant reduction in stage I: (65.28±2.78; 90.23±11.36), stage II: (59.76±6.56; 63.13±7.85), stage III: (49.16±6.17; 39.76±6.34) and stage IV: (37.44±4.78; 22.43±5.55) COPD patients as compared to healthy controls (100.33±7.471;105.03±13.08 P<0.001) respectively. The level of serum MDA and protein carbonyl was increased significantly in [stage I: (6.23±0.81nmol/ml, 5.64±2.94nmol/mg) stage II: (7.94±1.26nmol/ml, 8.1±2.33 nmol/mg), stage III: (9.42±1.51nmol/ml, 9.66±3.12nmol/mgs) and stage IV: (11.53±1.23nmol/ml, 11.13±2.17nmol/mg] COPD patients as compared to controls (4.19±1.79nmol/ml, 3.50±1.87nmol /mg) respectively. Where as a significant concomitant decreased was observed in vitamin E, vitamin C and reduced glutathione in [stage I: (1.09±0.37mg/dl; 0.98±0.34mg/dl; 28.24±6.12mg/dl), stage II: (0.806±0.27mg/dl, 0.69±0.28mg/dl, 22.42±4.50mg/dl), stage III: (0.608±0.15mg/dl, 0.53±0.09mg/dl, 17.67±4.45mg/dl) and stage IV: (0.48±0.11mg/dl, 0.43± 0.10mg/dl, 13.73±2.76mg/dl) COPD patients as compared to controls (1.51±0.40mg/dl, 1.41±0.59 mg/dl, 34.26±4.96mg/dl) respectively. We found a significant negative correlation between the MDA and protein carbonyl with the FEV1% predicted and positive correlation between the vitamin C, vitamin E and GSH with the marker of airflow obstruction (FEV1% predicted) in COPD patients. Conclusion: From this study we conclude that as the severity of disease increases FEV1% predicted decreases. These changes are associated with an increase in oxidative stress and a concomitant decrease in non-enzymatic antioxidants studied.