Secondhand smoking and matrix metalloproteinase-2 and -9 gene expression in saphenous veins of women nonsmokers

Abstract

Background: Active smoking upregulated matrix metalloproteinase-2 (MMP-2) and MMP-9 gene expression in saphenous veins (SVs) before coronary operation. However, little is known about the effects of secondhand smoke (SHS), a smoking status that is more widely harmful to the general population, on MMP gene expression in SVs. Health effects of SHS were investigated mainly in nonsmokers married to smokers. Because the vast majority of women are nonsmokers in China, we had an opportunity to evaluate the relations between SHS and MMP gene expression in SVs of women patients before operation.

Methods: A total of 258 woman patients were divided into three groups: control group, nonsmokers; SHS group, patients exposed to SHS until operation; active smoking group, patients who smoked a minimum of 1 package of cigarettes every day for more than 20 years. Messenger RNA and protein levels of MMP-2 and MMP-9 were analyzed. Saphenous vein graft patency after coronary operation was evaluated.

Results: The clinical backgrounds in the three groups were comparable. Compared with the control group, MMP-2 and MMP-9 gene expression was significantly increased in the SHS and active smoking groups (p<0.05). The degree of MMP gene expression changed by SHS or active smoking was comparable. A significant difference of SV graft patency was found among the three groups. An association of increased MMP gene expression with lowered SV graft patency was found in follow-up.

Conclusions: Our data revealed that SHS had similar power as active smoking to affect MMP gene expression in SVs before operation and SV graft patency after coronary operation in women nonsmokers.