Co‑enzyme Q10 (Ubiquinone)

Coenzyme Q10 (ubiquinone) is a fat-soluble substance found in almost all cells. It plays a role in energy production in the mitochondria, the tiny energy factories of the cell, and acts as an antioxidant. The body makes coenzyme Q10 itself; part of it also comes from food. In the blood, it is mainly carried with cholesterol, so the value moves along with the cholesterol level and says little about the amount in muscles or other tissues.

• A low value, for example with use of cholesterol-lowering drugs (statins) or with low cholesterol, without it being proven that this causes symptoms
• Rarely: a sign of an inherited coenzyme Q10 deficiency; that diagnosis is made with muscle and DNA testing, not with this blood test

With an abnormal value and no other signs, there is usually no follow-up. With muscle symptoms during statin use, the doctor usually considers a lower dose or a different statin; a coenzyme Q10 supplement is not a standard part of this. If an inherited metabolic disease is strongly suspected, the GP refers you to a specialized center.

In people without symptoms, a low or high value has no established meaning for health; in hospital, the test is mainly used for a specific question, such as a suspected metabolic disease. The value in the blood depends strongly on the cholesterol level and says little about the amount in muscles or other tissues. An inherited deficiency is diagnosed in a specialized center with muscle and DNA testing.

• The cholesterol level largely determines the result; statins and low cholesterol lower the value, high cholesterol raises it.
• Supplements with coenzyme Q10 raise the value in the blood.
• Measurement methods and reference values differ between laboratories.

An inherited coenzyme Q10 deficiency is very rare; it is estimated to occur in fewer than 1 in 100,000 children. How often a low value in the blood occurs in healthy people or in people who use statins is not well known and has no established meaning for health.

The result says little in healthy people. Even with muscle symptoms caused by statins, the result adds little: the guideline on side effects of statins found no scientific evidence for adding a coenzyme Q10 supplement, so a low result does not change the management of statin use. If an inherited mitochondrial disorder (a disease of energy metabolism) is suspected, testing in a specialized center is needed, not this blood test on its own.

• A low value can cause unnecessary worry or lead someone to stop a statin on their own initiative, even though the statin lowers the risk of cardiovascular disease.
• A low value can lead to buying supplements whose benefit has not been shown.

• FMS Richtlijnendatabase: Erfelijke dyslipidemie in de 2e en 3e lijn, module Statinegerelateerde bijwerkingen
• Kinderneurologie.eu: Primaire co-enzym Q10 deficiëntie
• Radboudumc: Mitochondriële aandoeningen