Coenzyme Q10 supplementation reduces oxidative stress and increases antioxidant enzyme activity in patients with coronary artery disease.

OBJECTIVE The purpose of this study was to investigate the effect of coenzyme Q10 supplementation on oxidative stress and antioxidant enzyme activity in patients with coronary artery disease (CAD). METHODS This was an intervention study. Patients who were identified by cardiac catheterization as having at least 50% stenosis of one major coronary artery or receiving percutaneous transluminal coronary angioplasty (n = 51) were randomly assigned to the placebo group (n = 14) or one of the two coenzyme Q10-supplemented groups (60 mg/d, n = 19 [Q10-60 group]; 150 mg/d, n = 18 [Q10-150 group]). Intervention was administered for 12 wk. Patients' blood samples were analyzed every 4 wk for plasma coenzyme Q10 concentrations, malondialdehyde (MDA), and antioxidant enzyme (catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase) activity. RESULTS Forty-three subjects with CAD completed intervention study. Plasma coenzyme Q10 concentration increased significantly after coenzyme the Q10-150 intervention (P < 0.01). The MDA levels were significantly lower than baseline in the Q10-150 group at week 4 (P = 0.03). The Q10-150 group had significantly lower MDA levels than the placebo group at week 8 (P = 0.03). With respect to antioxidant enzyme activity, subjects in the Q10-150 group had significantly higher CAT (P = 0.03) and SOD (P = 0.03) activity than the placebo group at week 12. The plasma coenzyme Q10 concentration was significantly correlated with MDA levels (r = -0.35, P = 0.02) and CAT (r = 0.43, P = 0.01) and SOD activity (r = 0.39, P = 0.01). The ratio of plasma coenzyme Q10 to total cholesterol was significantly correlated with SOD activity (r = 0.39, P = 0.02). The ratio of plasma coenzyme Q10 to low-density lipoprotein was significantly correlated with CAT (r = 0.35, P = 0.04) and SOD (r = 0.45, P = 0.01) activity. However, there was no relation between coenzyme Q10 concentration and glutathione peroxidase activity. CONCLUSION Coenzyme Q10 supplements at a dose of 150 mg can decrease oxidative stress and increase antioxidant enzyme activity in patients with CAD. A higher dose of coenzyme Q10 supplements (>150 mg/d) might promote rapid and sustainable antioxidation in patients with CAD.