Introduction:
Oxidative stress is among the major components of cardiovascular disease pathogenesis. Thiols play a significant role in prevention of oxidative stress in the cell. The purpose of this study is to investigate the relationship between the severity of coronary artery disease and disulphide/native thiol ratio, also determine if this ratio can be used as a marker of oxidative stress in this population.

Material and Methods:
A total number of 107 patients with angiographically established coronary artery disease and 26 control subjects with normal coronary arteries were enrolled. The mean Gensini score of patients were calculated (mean=30) and a score of 29 or below was considered as mild and a score of 30 or higher coronary artery disease as severe. Serum total, native thiol was measured and the disulphide and disulphide/native thiol ratio were calculated as described by Erel&Neselioglu.

Results:
Patients with mild and severe coronary artery disease had significantly lower native thiol levels and higher disulphide/native thiol ratio levels when compared to the control subjects. Also severe disease’s disulphide/native thiol ratio were higher than mild.

Conclusions:
The increased disulphide/native thiol ratio related with the severity of coronary artery disease, may reflect the augmented oxidative stress in coronary artery disease.