Coenzyme Q(10) dose-escalation study in hemodialysis patients: safety, tolerability, and effect on oxidative stress

BACKGROUND: Coenzyme Q(10) (CoQ(10)) supplementation improves mitochondrial coupling of respiration to oxidative phosphorylation, decreases superoxide production in endothelial cells, and may improve functional cardiac capacity in patients with congestive heart failure. There are no studies evaluating the safety, tolerability and efficacy of varying doses of CoQ(10) in chronic hemodialysis patients, a population subject to increased oxidative stress. METHODS: We performed a dose escalation study to test the hypothesis that CoQ(10) therapy is safe, well-tolerated, and improves biomarkers of oxidative stress in patients receiving hemodialysis therapy. Plasma concentrations of F(2)-isoprostanes and isofurans were measured to assess systemic oxidative stress and plasma CoQ(10) concentrations were measured to determine dose, concentration and response relationships. RESULTS: Fifteen of the 20 subjects completed the entire dose escalation sequence. Mean CoQ(10) levels increased in a linear fashion from 704 ± 286 ng/mL at baseline to 4033 ± 1637 ng/mL, and plasma isofuran concentrations decreased from 141 ± 67.5 pg/mL at baseline to 72.2 ± 37.5 pg/mL at the completion of the study (P = 0.003 vs. baseline and P < 0.001 for the effect of dose escalation on isofurans). Plasma F(2)-isoprostane concentrations did not change during the study. CONCLUSIONS: CoQ(10) supplementation at doses as high as 1800 mg per day was safe in all subjects and well-tolerated in most. Short-term daily CoQ(10) supplementation decreased plasma isofuran concentrations in a dose dependent manner. CoQ(10) supplementation may improve mitochondrial function and decrease oxidative stress in patients receiving hemodialysis. TRIAL REGISTRATION: This clinical trial was registered on clinicaltrials.gov [NCT00908297] on May 21, 2009.