Clinical aspects of coenzyme Q10: An update

The fundamental role of coenzyme Q10 (CoQ10) in mitochondrial bioenergetics and its well-acknowledged antioxidant properties constitute the basis for its clinical applications, although some of its effects may be related to a gene induction mechanism. Cardiovascular disease is still the main field of study and the latest findings confirm a role of CoQ10 in improving endothelial function. The possible relation between CoQ10 deficiency and statin side effects is highly debated, particularly the key issue of whether CoQ10 supplementation counteracts statin myalgias. Furthermore, in cardiac patients, plasma CoQ10 was found to be an independent predictor of mortality. Studies on CoQ10 and physical exercise have confirmed its effect in improving subjective fatigue sensation and physical performance and in opposing exercise-related damage. In the field of mitochondrial myopathies, primary CoQ10 deficiencies have been identified, involving different genes of the CoQ10 biosynthetic pathway; some of these conditions were found to be highly responsive to CoQ10 administration. The initial observations of CoQ10 effects in Parkinson's and Huntington's diseases have been extended to Friedreich's ataxia, where CoQ10 and other quinones have been tested. CoQ10 is presently being used in a large phase III trial in Parkinson's disease. CoQ10 has been found to improve sperm count and motility on asthenozoospermia. Moreover, for the first time CoQ10 was found to decrease the incidence of preeclampsia in pregnancy. The ability of CoQ10 to mitigate headache symptoms in adults was also verified in pediatric and adolescent populations.