Commentary to: "The Effects of Coenzyme Q10 Supplementation on Blood Pressures Among Patients with Metabolic Diseases: A Systematic Review and Meta-analysis of Randomized Controlled Trials"

Effect of Coenzyme Q10 Supplementation on Vascular Endothelial Function: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Coenzyme Q10 (CoQ10) has gained attention as a potential therapeutic agent for improving endothelial function. Several randomized clinical trials have investigated CoQ10 supplementation's effect on endothelial function. However, these studies have yielded conflicting results, therefore this systematic review and meta-analysis were conducted.

AIM

This systematic review and meta-analysis were conducted to assess the effects of CoQ10 supplementation on endothelial factors.

METHODS

A comprehensive search was done in numerous databases until July 19th, 2023. Quantitative data synthesis was performed using a random-effects model, with weight mean difference (WMD) and 95% confidence intervals (CI). Standard methods were used for the assessment of heterogeneity, meta-regression, sensitivity analysis, and publication bias.

RESULTS

12 studies comprising 489 subjects were included in the meta-analysis. The results demonstrated significant increases in Flow Mediated Dilation (FMD) after CoQ10 supplementation (WMD: 1.45; 95% CI: 0.55 to 2.36; p < 0.02), but there is no increase in Vascular cell adhesion protein (VCAM), and Intercellular adhesion molecule (ICAM) following Q10 supplementation (VCAM: SMD: - 0.34; 95% CI: - 0.74 to - 0.06; p < 0.10) (ICAM: SMD: - 0.18; 95% CI: - 0.82 to 0.46; p < 0.57). The sensitivity analysis showed that the effect size was robust in FMD and VCAM. In meta-regression, changes in FMD percent were associated with the dose of supplementation (slope: 0.01; 95% CI: 0.004 to 0.03; p = 0.006).

CONCLUSIONS

CoQ10 supplementation has a positive effect on FMD in a dose-dependent manner. Our findings show that CoQ10 has an effect on FMD after 8 weeks of consumption. Additional research is warranted to establish the relationship between CoQ10 supplementation and endothelial function.

Alleviating effects of coenzyme Q10 supplements on biomarkers of inflammation and oxidative stress: results from an umbrella meta-analysis

Introduction: Although several meta-analyses support the positive effect of coenzyme Q10 (CoQ10) on biomarkers of oxidative stress and inflammation, the results of some other studies reject such effects. Methods: Therefore, in this umbrella meta-analysis, we performed a comprehensive systematic search in such databases as Web of Science, PubMed, Scopus, Embase, and Google Scholar up to January 2023. Results: Based on standardized mean difference analysis, CoQ10 supplementation significantly decreased serum C-reactive protein (CRP) (ESSMD = -0.39; 95% CI: 0.77, -0.01, p = 0.042) and malondialdehyde (MDA) (ESSMD = -1.17; 95% CI: 1.55, -0.79, p < 0.001), while it increased the total antioxidant capacity (TAC) (ESSMD = 1.21; 95% CI: 0.61, 1.81, p < 0.001) and serum superoxide dismutase (SOD) activity (ESSMD = 1.08; 95% CI: 0.37, 1.79, p = 0.003). However, CoQ10 supplementation had no significant reducing effect on tumor-necrosis factor-alpha (TNF- α) (ESSMD = -0.70; 95% CI: 2.09, 0.68, p = 0.320) and interleukin-6 (IL-6) levels (ESSMD = -0.85; 95% CI: 1.71, 0.01, p = 0.053). Based on weighted mean difference analysis, CoQ10 supplementation considerably decreased TNF-α (ESWMD = -0.46, 95% CI: 0.65, -0.27; p < 0.001), IL-6 (ESWMD = -0.92, 95% CI: 1.40, -0.45; p < 0.001), and CRP levels (effect sizes WMD = -0.28, 95% CI: 0.47, -0.09; p < 0.001). Discussion: The results of our meta-analysis supported the alleviating effects of CoQ10 on markers of inflammation cautiously. However, CoQ10 had antioxidant effects regarding the improvement of all the studied antioxidant and oxidative stress biomarkers. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=323861, identifier CRD42022323861.

Hypertension and Dyslipidemia Combined Therapeutic Approaches

Treating blood pressure (BP) alone may provide only limited benefits while it is recommendable to manage the total cardiovascular risk. To date, several studies have shown that concomitant treatment of hypertension and dyslipidemia with non-pharmacological approaches and/or metabolically neutral antihypertensive drugs and statins produce a significantly greater reduction of the risk of developing cardiovascular disease. Thus, in this review article, we summarize the available evidence regarding non-pharmacological and pharmacological approaches with a favourable effect on both BP and lipids.

Diabetes, Age, and Duration of Supplementation Subgroup Analysis for the Effect of Coenzyme Q10 on Oxidative Stress: A Systematic Review and Meta-Analysis

BACKGROUND

Coenzyme Q10 (CoQ10) has been known as ubiquinone or ubidecarenone, which is a kind of lipid-soluble and vitamin-like antioxidant. It has a potent antioxidant effect against oxidation status via various mechanisms, including its ability to regenerate other antioxidants, such as vitamin E and vitamin C, and to increase antioxidant enzymes. Moreover, CoQ10 can quench free radicals and prevent lipid peroxidation. The aim of this systematic review and meta-analysis was to evaluate the effect of CoQ10 on oxidative stress variables.

METHODS

A comprehensive electronic database search in Scopus, Web of Science, Embase, Cochrane Library, and Medline was performed to identify eligible randomized clinical trials. A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of the Cochrane risk of bias assessment tool.

RESULTS

To evaluate the effect of CoQ10 supplementation, 17 trials and 972 participants were included for the meta-analysis. The pooled analysis of primary studies showed that CoQ10 increased serum total antioxidant capacity (standardized mean difference [SMD] 0.62 mmol/L, 95% CI 0.18-1.05, I2 = 76.1%, p ˂ 0.001) and superoxide dismutase (SMD 0.40 U/mg, 95% CI 0.12-0.67, I2 = 9.6%, p ˂ 0.345) levels and decreased malondialdehyde (SMD -1.02 mmol/L, 95% CI -1.60 to -0.44, I2 = 88.2%, p ˂ 0.001) level significantly compared to the placebo group. Although the effect of CoQ10 on nitric oxide (SMD 1.01 µmol/L, 95% CI -1.53 to 3.54, p ˂ 0.001, I2 = 97.8%) and glutathione peroxidase (SMD -0.01 mmol/L, 95% CI -0.86 to 0.84, p ˂ 0.001, I2 = 88.6%) was not significant, CoQ10 can be mentioned as an improvement in antioxidant defense status against reactive oxygen species.

CONCLUSION

These supplements have positive effects on antioxidant defense against oxidizing agents and elevate antioxidant enzyme levels in the body. However, due to limited research the results should be taken with caution.

Coenzyme Q10: Clinical Applications in Cardiovascular Diseases

Coenzyme Q₁₀ (CoQ₁₀) is a ubiquitous factor present in cell membranes and mitochondria, both in its reduced (ubiquinol) and oxidized (ubiquinone) forms. Its levels are high in organs with high metabolism such as the heart, kidneys, and liver because it acts as an energy transfer molecule but could be reduced by aging, genetic factors, drugs (e.g., statins), cardiovascular (CV) diseases, degenerative muscle disorders, and neurodegenerative diseases. As CoQ₁₀ is endowed with significant antioxidant and anti-inflammatory features, useful to prevent free radical-induced damage and inflammatory signaling pathway activation, its depletion results in exacerbation of inflammatory processes. Therefore, exogenous CoQ₁₀ supplementation might be useful as an adjuvant in the treatment of cardiovascular diseases such as heart failure, atrial fibrillation, and myocardial infarction and in associated risk factors such as hypertension, insulin resistance, dyslipidemias, and obesity. This review aims to summarize the current evidences on the use of CoQ₁₀ supplementation as a therapeutic approach in cardiovascular diseases through the analysis of its clinical impact on patients' health and quality of life. A substantial reduction of inflammatory and oxidative stress markers has been observed in several randomized clinical trials (RCTs) focused on several of the abovementioned diseases, even if more RCTs, involving a larger number of patients, will be necessary to strengthen these interesting findings.