Effects of Coenzyme [Q.sub.10] Supplementation on Lipid Profiles in Adults: A Meta-analysis of Randomized Controlled Trials

Context: Previous meta-analyses have suggested that the effects of coenzyme [Q.sub.10] (Co[Q.sub.10]) on lipid profiles remain debatable. Additionally, no meta-analysis has explored the optimal intake of Co[Q.sub.10] for attenuating lipid profiles in adults. Objective: This study conducted a meta-analysis to determine the effects of Co[Q.sub.10] on lipid profiles and assess their dose--response relationships in adults. Methods: Databases (Web of Science, PubMed/Medline, Embase, and the Cochrane Library) were systematically searched until August 10, 2022. The random effects model was used to calculate the mean differences (MDs) and 95% CI for changes in circulating lipid profiles. The novel single-stage restricted cubic spline regression model was applied to explore nonlinear dose--response relationships. Results: Fifty randomized controlled trials with a total of 2794 participants were included in the qualitative synthesis. The pooled analysis revealed that Co[Q.sub.10] supplementation significantly reduced total cholesterol (TC) (MD -5.53 mg/dL; 95% CI -8.40, -2.66; [I.sup.2] = 70%), low-density lipoprotein cholesterol (LDL-C) (MD -3.03 mg/dL; 95% CI -5.25, -0.81; [I.sup.2] = 54%), and triglycerides (TGs) (MD -9.06 mg/dL; 95% CI -14.04, -4.08; [I.sup.2] = 65%) and increased high-density lipoprotein cholesterol (HDL-C) (MD 0.83 mg/dL; 95% CI 0.01, 1.65; [I.sup.2] = 82%). The dose--response analysis showed an inverse J-shaped nonlinear pattern between Co[Q.sub.10] supplementation and TC in which 400-500 mg/day Co[Q.sub.10] largely reduced TC ([chi square] = 48.54, P< .01). Conclusion: Co[Q.sub.10] supplementation decreased the TC, LDL-C, and TG levels, and increased HDL-C levels in adults, and the dosage of 400 to 500 mg/day achieved the greatest effect on TC. Key Words: Co[Q.sub.10] supplementation, lipid profiles, dyslipidemia, meta-analysis