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Coenzyme Q10 for Patients with Parkinson's Disease: A Systematic Review and Meta-Analysis

Ahmed Negida, Ahmed Menshawy, Gehad El Ashal, Yasmin Elfouly, Yasmein Hani, Yasmin Hegazy, Samar El Ghonimy, Samar Fouda, Yomna Rashad
CNS & Neurological Disorders - Drug Targets 2016 15(1):45-53

Bibliography

PubMed
PMID 26553164
DOI
10.2174/1871527314666150821103306
Funding
A specific funding statement for the meta-analysis was not identified in the accessible PubMed record checked during this audit.
Competing interests
A specific author conflict-of-interest statement was not identified in the accessible publication record checked during this audit.

Study snapshot

DesignSystematic review and meta-analysis of randomized controlled trials
ModelPRISMA-guided systematic review and meta-analysis of randomized controlled trials comparing CoQ10 with placebo in patients with Parkinson disease.
Sample5 randomized controlled trials; 981 patients.
InterventionCoQ10 versus placebo across Parkinson-disease RCTs using different doses and disease stages; pooled outcomes focused on UPDRS and Schwab-England function.
Duration
EndpointsTotal UPDRS; UPDRS Part I; UPDRS Part II; UPDRS Part III; Schwab and England ADL score; Motor function; Quality/function

What the study showed, in plain terms

This 2016 systematic review pooled five randomized CoQ10 trials involving 981 people with Parkinson disease. Across total UPDRS, its mental, activities-of-daily-living and motor subscales, and the Schwab-England score, the pooled effects did not favor CoQ10.

The effect estimates were all close to zero: total UPDRS SMD -0.05, UPDRS I -0.03, UPDRS II -0.10, UPDRS III -0.05, and Schwab-England +0.08, with confidence intervals crossing no effect.

The pooled conclusion is consistent with the large QE3 trial: CoQ10 has not demonstrated a clinically meaningful benefit for Parkinson-disease motor/function outcomes despite plausible mitochondrial mechanisms.

Key findings

Total UPDRS: SMD -0.05, 95% CI approximately -0.10 to 0.15; no significant benefit.

UPDRS Part I: SMD -0.03, 95% CI -0.23 to 0.17; no significant benefit.

UPDRS Part II: SMD -0.10, 95% CI -0.35 to 0.15; no significant benefit.

UPDRS Part III: SMD -0.05, 95% CI approximately -0.07 to 0.17; no significant benefit.

Schwab and England score: SMD +0.08, 95% CI -0.13 to 0.29; no significant benefit.

Five RCTs/981 patients were pooled under PRISMA methodology; the review conclusion did not support CoQ10 for Parkinson-disease motor or functional outcomes.

What this study can and cannot tell us

Only five RCTs were available and they differed in CoQ10 dose, disease stage, trial duration and design.

The pooled dataset is heavily influenced by larger negative trials, especially QE3, which is appropriate for precision but means smaller mechanistically interesting studies contribute little weight.

The meta-analysis primarily addresses clinical Parkinson-disease outcomes; it does not refute every biochemical effect of CoQ10, but biochemical effects are not equivalent to clinical efficacy.

The accessible abstract does not provide detailed outcome-specific heterogeneity/risk-of-bias statistics for every pooled analysis, so those values are not invented here.

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Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology