The effects of coenzyme Q10 supplementation on biomarkers of inflammation and oxidative stress in among coronary artery disease: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: Systemic inflammation and oxidative stress significantly contribute in developing coronary artery disease (CAD). This systematic review and meta-analysis was aimed to determine the effects of coenzyme Q10 (CoQ10) supplementation on biomarkers of inflammation and oxidative stress among patients with CAD.

METHODS: The electronic databases including MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library databases were systematically searched until Oct 2018. The quality assessment and heterogeneity of the selected randomized clinical Trials (RCTs) were examined using the Cochrane Collaboration risk of bias tool, and Q and I2 tests, respectively. Given the presence of heterogeneity, random-effects model or fixed-effect model were used to pool standardized mean differences (SMDs) as summary effect sizes.

RESULTS: A total of 13 clinical RCTs of 912 potential citations were found to be eligible for the current meta-analysis. The pooled findings for biomarkers of inflammation and oxidative stress demonstrated that CoQ10 supplementation significantly increased superoxide dismutase (SOD) (SMD 2.63; 95% CI, 1.17, 4.09, P < 0.001; I2  = 94.5%) and catalase (CAT) levels (SMD 1.00; 95% CI, 0.57, 1.43, P < 0.001; I2  = 24.5%), and significantly reduced malondialdehyde (MDA) (SMD - 4.29; 95% CI - 6.72, - 1.86, P = 0.001; I2  = 97.6%) and diene levels (SMD - 2.40; 95% CI - 3.11, - 1.68, P < 0.001; I2  = 72.6%). We did not observe any significant effect of CoQ10 supplementation on C-reactive protein (CRP) (SMD - 0.62; 95% CI - 1.31, 0.08, P = 0.08; I2  = 87.9%), tumor necrosis factor alpha (TNF-α) (SMD 0.22; 95% CI - 1.07, 1.51, P = 0.73; I2  = 89.7%), interleukin-6 (IL-6) (SMD - 1.63; 95% CI - 3.43, 0.17, P = 0.07; I2  = 95.2%), and glutathione peroxidase (GPx) levels (SMD 0.14; 95% CI - 0.77, 1.04, P = 0.76; I2  = 78.7%).

CONCLUSIONS: Overall, this meta-analysis demonstrated CoQ10 supplementation increased SOD and CAT, and decreased MDA and diene levels, but did not affect CRP, TNF-α, IL-6, and GPx levels among patients with CAD.