Abstract
BACKGROUND: Oxidative stress is highly prevalent in patients with end-stage renal disease and is linked to excess cardiovascular risk. Identifying therapies that reduce oxidative stress has the potential to improve cardiovascular outcomes in patients undergoing maintenance dialysis. STUDY DESIGN: Placebo-controlled, 3-arm, double-blind, randomized, clinical trial. SETTING & PARTICIPANTS: 65 patients undergoing thrice-weekly maintenance hemodialysis. INTERVENTION: Patients were randomly assigned in a 1:1:1 ratio to receive once-daily coenzyme Q(10) (CoQ(10); 600 or 1,200mg) or matching placebo for 4 months. OUTCOMES: The primary outcome was plasma oxidative stress, defined as plasma concentration of F(2)-isoprotanes. Secondary outcomes included levels of plasma isofurans, levels of cardiac biomarkers, predialysis blood pressure, and safety/tolerability. MEASUREMENTS: F(2)-isoprostanes and isofurans were measured as plasma markers of oxidative stress, and N-terminal pro-brain natriuretic peptide and troponin T were measured as cardiac biomarkers at baseline and 1, 2, and 4 months. RESULTS: Of 80 randomly assigned patients, 15 were excluded due to not completing at least 1 postbaseline study visit and 65 were included in the primary intention-to-treat analysis. No treatment-related major adverse events occurred. Daily treatment with 1,200mg, but not 600mg, of CoQ(10) significantly reduced plasma F(2)-isoprostanes concentrations at 4 months compared to placebo (adjusted mean changes of -10.7 [95% CI, -7.1 to -14.3] pg/mL [P<0.001] and -8.3 [95% CI, -5.5 to -11.0] pg/mL [P=0.1], respectively). There were no significant effects of CoQ(10) treatment on levels of plasma isofurans, cardiac biomarkers, or predialysis blood pressures. LIMITATIONS: Study not powered to detect small treatment effects; difference in baseline characteristics among randomized groups. CONCLUSIONS: In patients undergoing maintenance hemodialysis, daily supplementation with 1,200mg of CoQ(10) is safe and results in a reduction in plasma concentrations of F(2)-isoprostanes, a marker of oxidative stress. Future studies are needed to determine whether CoQ(10) supplementation improves clinical outcomes for patients undergoing maintenance hemodialysis.