To investigate the effects of smoking on serum oxidative stress and inflammatory factors in patients with chronic obstructive pulmonary disease (COPD).

The male residents age ranged from 40 year old to 79 year-old of Maoming city were divided into four groups according to their lung function and smoking status including COPD smoke group, COPD non-smoke group, non-COPD smoke group , and non-COPD non-smoke group, 40 cases in each group. Oxidative stress indicators of serum (MDA, SOD) and inflammatory factors (IL-8, TNF-α) in the serum of the four groups were measured and analysis to understand their differences and relevance.

COPD: with mild non smoking group, smoking group of patients with mild COPD MDA, IL-8, TNF-α, SOD alpha level high level is low, in addition to TNF-α significant difference (P<0.05), MDA, IL-8 and SOD have no significant difference (P>0.05); compared with the non COPD smoking group, mild smoking group COPD IL-8 the high level of TNF-α, alpha (P<0.05), SOD (P<0.05), the low level of MDA is higher but the difference was not significant (P>0.05), but low levels of SOD (P<0.05), IL-8, TNF-α high level (P<0.05); mild COPD smoking group of MDA, IL-8, TNF-levels were significantly higher than non COPD group (non smoking P<0.05), and SOD (P<0.05). IL-8 and TNF-alpha were positively correlated with MDA (correlation coefficient r=0.487, 0.468, P<0.01); IL-8 was negatively correlated, TNF-alpha and SOD (correlation coefficient r=-0.463, -0.457, P all <0.01); was negatively related to IL-8, TNF-alpha and FEV₁%pred (correlation coefficient r, P the values were -0.492, P<0.01, -0.697, P<0.01). COPD: with mild non smoking group, smoking group of patients with mild COPD MDA, IL-8, TNF-α, SOD alpha level high level is low, in addition to TNF-α significant difference (P<0.05), MDA, IL-8 and SOD have no significant difference (P>0.05); compared with the non COPD smoking group, mild smoking group COPD IL-8 the high level of TNF-α, alpha (P<0.05), SOD (P<0.05), the low level of MDA is higher but the difference was not significant (P>0.05), but low levels of SOD (P<0.05), IL-8, TNF-α high level (P<0.05); mild COPD smoking group of MDA, IL-8, TNF-levels were significantly higher than non COPD group (non smoking P<0.05), and SOD (P<0.05). IL-8 and TNF-alpha were positively correlated with MDA (correlation coefficient r=0.487, 0.468, P<0.01); IL-8 was negatively correlated, TNF-alpha and SOD (correlation coefficient r=-0.463, -0.457, Pall<0.01); was negatively related to IL-8, TNF-alpha and FEV₁%pred (correlation coefficient r, P the values were -0.492, P<0.01, -0.697, P<0.01).

In non-COPD group, compared with non-smokers, MDA, IL-8, TNF-αand SOD were higher in smokers and the differences were more obvious in COPD patients. Among patients with mild COPD, IL-8 and TNF-α were positively correlated with MDA, but negatively correlated with SOD and FEV₁% pred. It suggested that the imbalance of oxidative stress caused by smoking may be caused by the reduction of antioxidants and oxidative stress imbalance can lead to increased inflammatory factors, and inflammatory factors will accelerate the decline in lung function, therefore leading to COPD.