Trace elements as a component of oxidative stress in COPD.

Objective: The purpose of this study was to assess the serum concentrations of those trace elements that act as a component of oxidative stress in COPD patients. Clinically stable COPD outpatients (n = 26) and healthy controls (n = 24) were studied.

Methodology: Serum concentrations of copper (Cu) and zinc (Zn) were determined using a Varian Spectra AA220 flame atomic absorption spectrophotometer. Serum concentration of iron (Fe) was measured by the ferene assay, using a commercially available kit (IL Test Iron) with the ILAb 900 autoanalyser. The lipid peroxidation product malondialdehyde (MDA) in serum samples was measured spectrophotometrically in terms of TBARS (thiobarbituric acid reactive substances).

Results: The serum MDA concentration in COPD patients was found to be similar to the control group (0.68 +/- 0.15 nmol/mL vs 0.62 +/- 0.13 nmol/mL, respectively; P= 0.163). The serum concentrations of the trace elements in both study groups were in the normal reference range. There was no difference in Fe concentration between COPD patients and the control group (0.81 +/- 0.38 micro g/mL vs 0.92 +/- 0.41 micro g/mL; P= 0.360). Copper concentrations were higher (1.06 +/- 0.26 microg/mL vs 0.92 +/- 0.19 microg/mL; P <0.040); while zinc was lower in the COPD group compared to the controls (0.83 +/- 0.25 microg/mL vs 1.03 +/- 0.23 microg/mL; P= 0.006). Serum Zn concentrations were lower in the severe COPD patients compared to mild-moderate COPD patients (P = 0.038).

Conclusion: The results of this study indicate that there are alterations in serum concentrations of trace elements in COPD patients, suggesting that they may play a role in the pathophysiology of this disease by virtue of their role in oxidative stress. We recommend further studies on the role of trace elements in the pathophysiology of COPD, their association with markers of oxidant/antioxidant status and on the clinical significance of their deficiency.