Coenzyme Q10 and vitamin E deficiency in Friedreich's ataxia: predictor of efficacy of vitamin E and coenzyme Q10 therapy

Eur J Neurol. 2008 Dec;15(12):1371-9. doi: 10.1111/j.1468-1331.2008.02318.x.


Background and purpose: A pilot study of high dose coenzyme Q(10) (CoQ(10))/vitamin E therapy in Friedreich's ataxia (FRDA) patients resulted in significant clinical improvements in most patients. This study investigated the potential for this treatment to modify clinical progression in FRDA in a randomized double blind trial.

Methods: Fifty FRDA patients were randomly divided into high or low dose CoQ(10)/ vitamin E groups. The change in International Co-operative Ataxia Ratings Scale (ICARS) was assessed over 2 years as the primary end-point. A post hoc analysis was made using cross-sectional data.

Results: At baseline serum CoQ(10) and vitamin E levels were significantly decreased in the FRDA patients (P < 0.001). During the trial CoQ(10) and vitamin E levels significantly increased in both groups (P < 0.01). The primary and secondary end-points were not significantly different between the therapy groups. When compared to cross-sectional data 49% of all patients demonstrated improved ICARS scores. This responder group had significantly lower baseline serum CoQ(10) levels.

Conclusions: A high proportion of FRDA patients have a decreased serum CoQ(10) level which was the best predictor of a positive clinical response to CoQ(10)/vitamin E therapy. Low and high dose CoQ(10)/vitamin E therapies were equally effective in improving ICARS scores.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antioxidants / administration & dosage
  • Dose-Response Relationship, Drug
  • Electron Transport Chain Complex Proteins / genetics
  • Electron Transport Chain Complex Proteins / metabolism
  • Endpoint Determination
  • Energy Metabolism / drug effects
  • Energy Metabolism / physiology
  • Female
  • Friedreich Ataxia / drug therapy*
  • Friedreich Ataxia / metabolism
  • Friedreich Ataxia / physiopathology
  • Humans
  • Male
  • Mitochondria / genetics
  • Mitochondria / metabolism
  • Muscle, Striated / metabolism
  • Muscle, Striated / physiopathology
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology
  • Predictive Value of Tests
  • Treatment Outcome
  • Ubiquinone / administration & dosage
  • Ubiquinone / analogs & derivatives*
  • Ubiquinone / blood
  • Ubiquinone / deficiency
  • Up-Regulation / drug effects
  • Up-Regulation / physiology
  • Vitamin E / administration & dosage*
  • Vitamin E Deficiency / blood
  • Vitamin E Deficiency / drug therapy*
  • Vitamin E Deficiency / physiopathology
  • Young Adult


  • Antioxidants
  • Electron Transport Chain Complex Proteins
  • Ubiquinone
  • Vitamin E
  • coenzyme Q10