Effects of coenzyme Q10 supplementation on inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

The aims of this meta-analysis were to evaluate the effects of coenzyme Q10 (CoQ10) supplementation on inflammatory mediators including C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) by analyzing published randomized controlled trials (RCTs). A systematic search in PubMed, Cochrane Library and Clinicaltrials.gov was performed to identify eligible RCTs. Data synthesis was performed using a random- or a fixed-effects model depending on the results of heterogeneity tests, and pooled data were displayed as weighed mean difference (WMD) and 95% confidence interval (CI). Seventeen RCTs were selected for the meta-analysis. CoQ10 supplementation significantly reduced the levels of circulating CRP (WMD: −0.35 mg/L, 95% CI: −0.64 to −0.05, P = 0.022), IL-6 (WMD: −1.61 pg/mL, 95% CI: −2.64 to −0.58, P = 0.002) and TNF-α (WMD: −0.49 pg/mL, 95% CI: −0.93 to −0.06, P = 0.027). The results of meta-regression showed that the changes of CRP were independent of baseline CRP, treatment duration, dosage, and patients characteristics. In the meta-regression analyses, a higher baseline IL-6 level was significantly associated with greater effects of CoQ10 on IL-6 levels (P for interaction = 0.006). In conclusion, this meta-analysis of RCTs suggests significant lowering effects of CoQ10 on CRP, IL-6 and TNF-α. However, results should be interpreted with caution because of the evidence of heterogeneity and limited number of studies.

Meta-analysis of CoQ10 intervention on net changes (95% CI) of CRP.CI, confidence interval.WMD, weighted mean difference; The horizontal lines denote the 95% CIs, some of which extend beyond the limits of the scales. The square represents the point estimate of each study. The diamond represents the overall pooled estimate of the treatment effect.106