Patient selleck chemicals suffering from CAD might suffer loss of coenzyme Q10 under higher oxidative stress [11�C14]. Subjects in the case group showed a significant higher lipid peroxide (MDA) level than control (Figure 2, P < 0.01), which is an indicator of free radical-induced damage during myocardial ischemia [24, 25]. There was a significant negatively correlations between the plasma coenzyme Q10 and MDA levels (Table 2, Model 1), but the statistical significance disappeared after adjusting for the potential confounders of CAD (Table 2, Models 2 and 3). In addition to oxidative stress, we assessed the activities of the major antioxidant enzymes directly involved in the neutralization of ROS. The activities of CAT and GPx were significantly lower in the case group compared to those of the control group (Figure 2).

As shown in Table 2, there was a significantly positive relationship between the levels of plasma coenzyme Q10 and CAT or GPx (Model 1), which disappeared after adjusting for age, gender or other potential confounders of CAD (Model 2 and 3). On the other hand, the activities of SOD were significantly higher in the case group and negative correlated with the concentration of plasma coenzyme Q10, even after adjusting for the potential confounders. The role of antioxidant enzymes defense against the ROS is controversial. In CAD patients, SOD activity may increase to protect against lipid peroxidation and against ROS [15, 26]. Coenzyme Q10 may assist SOD in the uptake of superoxide radical to form oxygen and hydrogen peroxide.

Traditional CAD risk factors such as gender [23] and age [20, 21, 23, 27] may also influence the plasma coenzyme Q10 concentration. In present study, males (�� = ?0.11, P < 0.01) and older patients (�� = ?0.01, P < 0.01) had significantly lower levels of plasma coenzyme Q10 in the case group compared to those in the control group. Other CAD risk factors such as blood pressure [28], obesity [21, 29], and smoking [30] may also affect coenzyme Q10 concentration. We have examined the correlations between the plasma coenzyme Q10 concentration and blood pressure, waist to hip ratio, or smoking habits (data Batimastat not shown). There was a significantly negative correlation between the plasma coenzyme Q10 concentration and systolic blood pressure (�� = ?0.00, P = 0.01), smoking (�� = ?0.10, P = 0.04), and waist to hip ratio (�� = ?0.26, P = 0.09). Therefore, we presume that the plasma coenzyme Q10 level was lower in the case group due to oxidative stress and the traditional CAD risk factors. Coenzyme Q10 is a lipid-soluble antioxidant, that is, transported by lipids and lipoprotein (especially LDL-C, 58%) in the blood [31].