Oxidative stress : a global evaluation in patients with acute coronary syndrome and stable angina

Background. Oxidative stress has been related to several pathologies, like coronary artery disease (CAD). We recently described a comprehensive index of oxidative status (OXYSCORE),reflecting both injuries and antioxidant defences in coronary patients. Objective: This study was performed to test OXY-SCORE. Methods. We enrolled 93 healthy subjects (58% males; age 24-72) and 197 CAD patients, 118 with stable angina (SA,77% males; age 40-81) and 79 with acute coronary syndrome (ACS, 70% males; age 35-80) . Plasma free and total malondialdehyde (F- and T-MDA), glutathione disulphide/reduced forms (GSSG/GSH) and urine isoprostane (iPF2α-III) levels were measured as markers of oxidative damage, and computed in the damage score (DS). GSH, α-and γ-tocopherol (TH), and individual antioxidant capacity (IAC), measured as indexes of antioxidant defence, were computed in the protection score (PS). OXY-SCORE was computed by subtracting PS from DS. Data were analysed by ANCOVA and ROC analysis. Results. In healthy subjects, MDA was associated with age and GSH, GSSG/GSH ratio and α-TH correlated with gender. OXY-SCORE (mean±SEM 0.31±0.10), was positively associated with both age (p=0.02) and male gender (p=0.03). OXY-SCORE was significantly higher in CAD subjects even after adjusting for age and gender (p<0.0001) and was also able to discriminate between ACS and AS (mean±SEM 1.4±0.11 and 0.92±0.08 respectively, p=0.001) with an area under the ROC curve of 0.66. Conclusions. OXY-SCORE is confirmed to be a comprehensive index of oxidative stress related to age, gender and CAD status. This marker also reflects the different clinical presentation of CAD.