Plasma coenzyme Q10 concentrations are not decreased in male patients with coronary atherosclerosis

Coenzyme Q(10) (CoQ(10)) is an important mitochondrial electron transfer component and has been postulated to function as a powerful antioxidant protecting LDL from oxidative damage. It could thus reduce the risk of cardiovascular disease. Thus far, beneficial effects of supplementation with CoQ(10) have been reported. To study the relation between unsupplemented concentrations of plasma CoQ(10) and coronary atherosclerosis, we performed a case-control study among 71 male cases with angiographically documented severe coronary atherosclerosis and 69 healthy male controls free from symptomatic cardiovascular disease and without atherosclerotic plaques in the carotid artery. Plasma CoQ(10) concentrations (mean +/- SE) were 0.86 +/- 0.04 vs. 0.83 +/- 0.04 mu mol/l for cases and controls, respectively. The CoQ(10)/LDL-cholesterol ratio (mu mol/mmol) was slightly lower in cases than in controls (0.22 +/- 0.01 vs. 0.26 +/- 0.03). Differences in CoQ(10) concentrations and CoQ(10)/LDL-cholesterol ratio did not reach significance. The odds ratios (95% confidence interval) for the risk of coronary atherosclerosis calculated per mu mol/l increase of CoQ(10) was 1.12 (0.28-4.43) after adjustment for age, smoking habits, total cholesterol and diastolic blood pressure. We conclude that an unsupplemented plasma CoQ(10) concentration is not related to risk of coronary atherosclerosis.