E2 ModeratePreliminaryPEM unclearCross-SectionalPeer-reviewedReviewed
Coenzyme Q10 deficiency in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is related to fatigue, autonomic and neurocognitive symptoms and is another risk factor explaining the early mortality in ME/CFS due to cardiovascular disorder.
Maes, Michael, Mihaylova, Ivanka, Kubera, Marta et al. · Neuro endocrinology letters · 2009
Quick Summary
This study found that people with ME/CFS have significantly lower levels of Coenzyme Q10 (CoQ10), a substance that helps cells produce energy, compared to healthy people. Nearly 45% of ME/CFS patients had CoQ10 levels below what was found in any of the healthy control group. Low CoQ10 was connected to worse fatigue, problems with heart and blood pressure regulation, and difficulty with thinking and memory.
Why It Matters
CoQ10 deficiency may explain multiple ME/CFS symptoms and could represent a treatable contributing factor. The association with premature cardiovascular mortality in ME/CFS patients suggests CoQ10 supplementation warrants investigation as a potential intervention to prevent serious cardiac complications.
Observed Findings
- Plasma CoQ10 levels were significantly lower in ME/CFS patients compared to healthy controls (p=0.00001).
- 44.8% of ME/CFS patients had CoQ10 levels below the lowest value detected in any healthy control (490 µg/L).
- Inverse correlations existed between plasma CoQ10 and total FibroFatigue scale scores, fatigue severity, and autonomic symptom severity.
- Patients with very low CoQ10 (<390 µg/L) reported significantly more concentration and memory disturbances.
Inferred Conclusions
- CoQ10 depletion plays a role in ME/CFS pathophysiology and may contribute to fatigue, autonomic dysfunction, and cognitive symptoms.
- ME/CFS patients may benefit from CoQ10 supplementation to normalize the low CoQ10 syndrome and improve related symptoms.
- Low CoQ10 may explain the well-documented early cardiovascular mortality in ME/CFS, and statin therapy without CoQ10 replacement could be harmful in this population.
Remaining Questions
- Does correcting CoQ10 deficiency through supplementation actually improve ME/CFS symptoms and outcomes, and what dose and duration would be effective?
- Is low CoQ10 a primary disease mechanism or a secondary consequence, and how does it relate to the inflammatory and oxidative stress pathways in ME/CFS?
What This Study Does Not Prove
This study does not prove that CoQ10 deficiency causes ME/CFS symptoms—it only shows an association. It does not establish whether low CoQ10 is a primary pathological feature or a secondary consequence of the disease. The study cannot determine whether CoQ10 supplementation would actually improve symptoms or outcomes, as no intervention was tested.
Tags
Symptom:Cognitive DysfunctionOrthostatic IntoleranceFatigue
Biomarker:MetabolomicsBlood Biomarker
Method Flag:Weak Case DefinitionSmall SampleExploratory Only
Metadata
- PMID
- 20010505
- Review status
- Editor reviewed
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 12 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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