Methods: The TAC and TOS levels were assessed in the plasma of 30 coronary artery endarterectomy patients and compared to 30 control samples. Atherosclerotic plaque TAC and TOS levels were also evaluated in the patients’ group. The severity of coronary artery disease was calculated with the Gensini score index.

Results: The plasma TAC and TOS values were significantly lower in patients than in controls (p=0.008 and p=0.004 respectively). The TAC level was significantly lower in tissue than in plasma (0.11±0.03 mmol Trolox Equiv./L versus 0.65±0.25 mmol Trolox Equiv./L, p<0.001). The level of TOS was significantly higher in plasma than in tissue (0.80±0.46 μmol H2O2 equiv./L versus 10.9±3.7 μmol H2O2 equiv./L, p<0.001). Multiple linear regression analyses show that the Gensini score index was independently associated with plasma TAC levels (r=-0.898, p<0.001) and age (r=0.258, p=0.023).

Conclusion: The plasma TAC value, rather than tissue oxidative stress and antioxidant status, is related to atherosclerosis.