The serum levels of the trace element Cu, Zn, Cd and Pb and progression of COPD – a preliminary study

Abstract

There are evidence that high levels of heavy metals can play a key role in the development of COPD due to the induction of chronic inflammation and oxidative stress. Previous studies have reported that serum and urinary cadmium and lead concentrations were significantly associated with obstructive pulmonary disease. In the current preliminary study we assessed the serum levels of 4 trace elements (Cu, Zn, Cd, and Pb) in the serum of 30 COPD patients by аtomic absorption spectroscopy and evaluated their possible role as marker s in progression of the disease. The COPD patients were followed up for 2 years and clinical data for the progression of the disease were collected. The mean values of Cu was 152.2±34.8 (SEM) µg/l, Zn 1591.7±165.2 µg/l, Cd 0.414±0.02 µg/l and Pb 0.077±0.01 µg/l. Surprisingly, the levels of Pb were significantly lower in current smokers (n=6) than the “current non-smokers” (never smoked or ex-smokers, n=24) (p=0.040). Among the current non-smokers, the levels of Pb was significantly higher in patients which during the follow-up period increased the CAT score (p=0.005), and had worsening of the spirometric indexes (FEV1% pr., p=0.004; and FEV1%/FVC%, p=0.004) in comparison to those with decreased CAT scores and improved spirometric indexes. Similar relations were observed for the serum levels of Cd, but the results were significant only for FEV1% (p=0.011). The results of our study suggest that the trace elements Pb and Cd might be involved in deterioration of the COPD in non-and ex-smokers and might be used as prognostic biomarkers for progression. Further studies are warranted to confirm these preliminary results. Funded by projects 3AF/2019 and IUP3/2017, TrU.