Correspondence from the world of cardiology
Dear Sirs,
We wish to comment on two recent clinical trial studies relating to the use of supplementary coenzyme Q10 (CoQ10) for the treatment and prevention of cardiovascular disease.
In the first randomised controlled trial, the Q-Symbio study by Mortensen et al,1 oral supplementation with CoQ10 (300 mg/day for two years, as an adjuvant to conventional medication) in 420 patients with chronic heart failure (New York Heart Association class III or IV) reduced the risk of cardiac related mortality by 47% compared to placebo.
In the second randomised controlled trial, the KiSel-10 study by Alehagen et al,2 oral supplementation with CoQ10 (200 mg/day) and selenium (200 µg/day) for five years in 440 normal elderly Swedish individuals reduced the risk of cardiovascular related mortality by 54%.
The Q-Symbio and KiSel-10 clinical trials represent landmark studies in the treatment and prevention of cardiovascular disease. However, what is not immediately apparent from reading the above papers is the key importance of the type of supplemental CoQ10 used and also the blood CoQ10 level subsequently achieved. The type of CoQ10 used in the Q-Symbio and KiSel-10 studies, Bio-Quinone Q10 100 mg (licensed in the EU as Myoqinon®), was chosen because of its documented bioavailability; specifically the ability of a defined dosage to raise blood CoQ10 levels above the 3 µg/ml threshold required for clinical efficacy in cardiovascular disease.3,4
In addition to the study by Mortensen et al,1 three relevant smaller-scale randomised controlled clinical trials were identified (as listed on Medline) in which changes in blood CoQ10 levels were documented together with changes in clinical status, following CoQ10 supplementation in patients with chronic heart failure. One of these studies5 reported significantly improved functional capacity, left ventricular contractility and endothelial function in NYHA class II/III patients; supplementation with CoQ10 (300 mg/day for two months) correspondingly raised mean blood CoQ10 levels to 3.6 µg/ml. In the remaining studies,6,7 supplementation with CoQ10 (100–200 mg/day for three to six months) in NYHA class II/III patients did not result in significant clinical benefit; corresponding mean blood CoQ10 levels following supplementation in these studies were 2.0 µg/ml and 2.2 µg/ml respectively.
These data illustrate the importance of dosage and bioavailability of supplemental CoQ10, and the importance of raising blood CoQ10 levels above a therapeutic threshold of 3 µg/ml, for the effective management of chronic heart failure.
Conflict of interest
DM is medical adviser to Pharma Nord (UK) Ltd.
David Mantle
Medical Adviser
Pharma Nord (UK) Ltd, Morpeth, Northumberland NE61 2DB
([email protected])
References
1. Mortensen SA, Rosenfeldt F, Kumar A, et al. The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure. J Am Coll Cardiol HF 2014;2:641–9. http://dx.doi.org/10.1016/j.jchf.2014.06.008
2. Alehagen U, Johansson P, Bjornstedt M, et al. Cardiovascular mortality and N-terminal proBNP reduced after combined selenium and CoQ10 supplementation. Int J Cardiol 2013;167:1860–6. http://dx.doi.org/10.1016/j.ijcard.2012.04.156
3. Weis M, Mortensen SA, Rassing MR, et al. Bioavailability of four oral coenzyme Q10 formulations in healthy volunteers. Mol Aspects Med 1994:15:273–80.
4. Langsjoen PH, Langsjoen AM. Overview of the use of CoQ10 in cardiovascular disease. Biofactors 1999;9:273–84. http://dx.doi.org/10.1002/biof.5520090224
5. Belardinelli R, Mucaj A, Lacalaprice F, et al. CoQ10 and exercise training in chronic heart failure. Eur Heart J 2006;27:2675–81. http://dx.doi.org/10.1093/eurheartj/ehl158
6. Watson PS, Scalia GM, Galbraith A, et al. Lack of effect of CoQ10 on left ventricular function in patients with congestive heart failure. J Am Coll Cardiol 1999;33:1549–52. http://dx.doi.org/10.1016/S0735-1097(99)00064-9
7. Khatta M, Alexander BS, Krichten CM, et al. The effect of CoQ10 in patients with congestive heart failure. Ann Intern Med 2000;132:636–40. http://dx.doi.org/10.7326/0003-4819-132-8-200004180-00006
