Test Catalog

Test ID: Q10    
Coenzyme Q10, Reduced and Total, Plasma

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosis of primary CoQ10 deficiencies in some patients who are not supplemented with CoQ10


Diagnosis of coenzyme Q10 (CoQ10) deficiency in mitochondrial disorders


Monitoring CoQ10 status during treatment of various degenerative conditions including Parkinson and Alzheimer disease


This test is not useful for distinguishing primary CoQ10 deficiencies from acquired CoQ10 deficiencies.

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request

This test is appropriate for the diagnosis of secondary coenzyme Q10 (CoQ10) deficiency, and in some patients with primary CoQ10 deficiency who are not supplemented with CoQ10. It is also used to monitor CoQ10 status in patients with mitochondrial cytopathies, patients receiving statin therapy, or during treatment of various degenerative conditions including Parkinson and Alzheimer diseases.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Coenzyme Q10 (CoQ10) is an essential cofactor in the mitochondrial respiratory chain responsible for oxidative phosphorylation where it functions as an electron carrier and acts as an antioxidant. It is found in all cell membranes and is carried by lipoproteins in the circulation. Approximately 60% of CoQ10 is associated with low-density lipoprotein (LDL), 25% with high-density lipoprotein (HDL), and 15% with other lipoproteins. CoQ10 is present in the body in both the reduced and oxidized forms, with the antioxidant activity of CoQ10 dependent on both its concentration and its reduction-oxidation (redox) status.


CoQ10 deficiencies, which are clinically and genetically diverse, can occur due to defects in genes involved in the biosynthesis of ubiquinone (primary CoQ10 deficiency) or due to other causes such as mitochondrial disorders (secondary or CoQ10 deficiency).


Five major clinical phenotypes of CoQ10 deficiency have been described:

-Encephalomyopathy (elevated serum creatine kinase [CK], recurrent myoglobinuria, lactic acidosis)

-Cerebellar ataxia and atrophy (neuropathy, hypogonadism)

-Severe multisystemic infant form (nystagmus, optic atrophy, sensorineural hearing loss, dystonia, rapidly progressing nephropathy)


-Isolated myopathy (exercise intolerance, fatigue, elevated serum CK)


Treatment with CoQ10 in patients with mitochondrial cytopathies can improve mitochondrial respiration in both brain and skeletal muscle.


CoQ10 has been implicated in other disease processes, including Parkinson disease, diabetes, and Alzheimer disease, as well as in aging and oxidative stress. CoQ10 may also play a role in hydroxymethylglutaryl-CoA reductase inhibitor (statin) therapy; changes in CoQ10 may be relevant to statin-induced myalgia. Additionally, the redox status of CoQ10 may be a useful early marker for the detection of oxidative LDL modification.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


<18 years: 320-1,376 mcg/L

> or =18 years: 415-1,480 mcg/L



<18 years: 320-1,558 mcg/L

> or =18 years: 433-1,532 mcg/L



<18 years: 93-100%

> or =18 years: 92-98%


Miles MV, Horn PS, Tang PH, et al: Age-related changes in plasma coenzyme Q10 concentrations and redox state in apparently healthy children and adults. Clin Chim Acta 2004;34:139-144

Interpretation Provides information to assist in interpretation of the test results

Abnormal results are reported with a detailed interpretation including an overview of the results and their significance, a correlation to available clinical information provided with the specimen, differential diagnosis, and recommendations for additional testing when indicated and available.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Coenzyme Q10 (CoQ10) is sensitive to specimen handling and transport temperature. Failure to follow the specimen handling and transportation recommendations may lead to false-positive results.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Salviati L, Trevisson E, Doimo M, et al: Primary Coenzyme Q10 Deficiency. In GeneReviews. Edited by MP Adam, HH Ardinger, RA Pagon, et al. University of Washington, Seattle. 1993-2019. 2017 Jan 26. Accessed 05/07/2019. Available at https://www.ncbi.nlm.nih.gov/books/NBK410087/

2. Desbats MA, Lunardi G, Doimo M, et al: Genetic bases and clinical manifestations of coenzyme Q10 (CoQ 10) deficiency. J Inherit Metab Dis 2015 Jan;38(1):145-156

3. Littarru GP, Tiano L: Clinical aspects of coenzyme Q10: An update. Nutrition 2010;26:250-254

4. Steele PE, Tang PH, DeGrauw AJ, Miles MV: Clinical laboratory monitoring of coenzyme Q10 use in neurologic and muscular diseases. Am J Clin Pathol 2004 June;121:S113-S120

5. Banach M, Serban C, Ursoniu S, et al; Lipid and Blood Pressure Meta-analysis Collaboration (LBPMC) Group. Statin therapy and plasma coenzyme Q10 concentrations-A systematic review and meta-analysis of placebo-controlled trials. Pharmacol Res 2015 Sep;99:329-336