Also, the severity of COPD exacerbation was associated with elevated levels of zinc (Zn), Cu and lipid peroxidation (malondialdehyde, MDA); in COPD patients, serum Cu and MDA concentration were higher than in the controls,16 whereas serum paraoxonase (PON1) activity was lower. This evidence concerns the gene PON1 and chronic obstructive pulmonary disease.