Relevance of Trace Elements and Oxidative Stress in Chronic Obstructive Pulmonary Disease

Abstract

Background and Aims: Chronic Obstructive Pulmonary Disease (COPD) is a progressive and nonreversible lung disease caused by long-term exposure to harmful particles and gases, especially cigarette smoke. Emerging evidence suggests that trace minerals, including iron, copper, zinc, and the heavy metal cadmium, may also contribute to the pathogenesis and progression of this complex disease. The study was done in a tertiary care hospital in Kerala and assessed the role of trace elements and oxidative stress in the pathophysiology of COPD. Materials and Methods: The study comprised two groups, consisting of 30 healthy controls and 30 COPD samples. Plasma samples collected from the participants were used for the analysis of oxidative stress parameters such as lipid peroxidation, superoxide dismutase (SOD) activity, catalase activity, and glutathione concentration. The oxidative stress index (OSI) was calculated from the total oxidant status (TOS)/total antioxidant status (TAS) ratio. Plasma levels of iron, copper, zinc, and cadmium were analyzed and correlated with OSI to determine the interplay of environmental exposure to toxicants and their role in inducing oxidative stress. Results: The results showed an increase in plasma iron and copper levels in COPD with respect to healthy control, whereas cadmium showed an increasing trend. The OSI values obtained from the TOS/TAS ratio were higher in COPD with respect to control and showed a positive correlation to plasma levels of copper and cadmium. Pro-oxidant TBARS concentration was higher with a concurrent decrease in antioxidant enzymes SOD and catalase activity in COPD with respect to healthy controls. Conclusion: The study, carried out in a tertiary care hospital in Kerala, shed light on the role of plasma trace element/heavy metal imbalance in inducing oxidative stress in COPD. A significant increase in plasma iron levels may activate Fenton chemistry, thereby inducing oxidative stress, playing a major role in COPD pathophysiology. Copper and cadmium levels also positively correlated with OSI in COPD, indicating that trace elements in higher levels can lead to disease progression in COPD pathophysiology.