Higher Redox State of Coenzyme Q10 Is Associated with Higher Risk of All-Cause Mortality in a Sample from the Northern German General Population

Coenzyme Q10 (CoQ10) plays an important role in human health; for example, through the antioxidant function of its reduced form (ubiquinol). As the long-term health effects of circulating CoQ10 remain largely unknown, we examined the association of total CoQ10, ubiquinol, ubiquinone (oxidized CoQ10), and CoQ10 redox state (percentage of ubiquinone in total CoQ10) with all-cause mortality in a sample from the northern German general population. In <i>n</i> = 1333 individuals (60.1% females, median baseline age: 48.0 years [37.7; 58.0]), serum total CoQ10, ubiquinol, ubiquinone, and CoQ10 redox state were measured at baseline and found to be related to all-cause mortality using Cox regression models (adjusted for sex, age, body mass index, smoking, systolic blood pressure, total cholesterol, diabetes, and C-reactive protein). After 12.9 years [12.4; 17.1], <i>n</i> = 123 deaths had occurred. A higher CoQ10 redox state was independently associated with a higher risk of all-cause mortality after multivariable adjustment (HR: 1.18 [95% CI 1.02-1.36] per 1-SD increment, HR: 1.92 [95% CI 1.16-3.17] for tertile 3 vs. tertile 1), while higher ubiquinone levels were associated with greater all-cause mortality risk only in the unadjusted model. A higher CoQ10 redox state was associated with a higher risk of all-cause mortality in a population-based sample, possibly indicating detrimental long-term health effects of the lower antioxidant capacity of CoQ10.