Drug industry-funded study on statin drugs and coenzyme [Q.sub.10]

Townsend Letter for Doctors and Patients,  May, 2006  by Alan R. Gaby

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Twenty-one hypercholesterolemic patients (mean age, 56 years) who were otherwise healthy received 20 mg/day of simvastatin for six months. The mean left ventricular ejection fraction (LVEF) decreased from 61% at baseline to 58% after one month (p = 0.02), but returned to the baseline value at three and six months. The authors concluded that simvastatin treatment is not associated with impairment in left ventricular function in hypercholesterolemic patients after six months of treatment. The study was funded by Merck Sharp and Dohme (Australia).

Comment: Co[Q.sub.10] deficiency has been found in myocardial tissue of patients with congestive heart failure, and Co[Q.sub.10] supplementation improved heart failure in some but not all studies. In the new study, the authors' conclusion did not mention the significant decrease in LVEF that occurred after one month of simvastatin treatment. This decrease could be clinically significant for patients with heart failure or marginal myocardial function. There are case reports in which initiation of treatment with a statin drug was followed by cardiac decompensation in patients with previously stable heart failure.

The authors of the new study reported that plasma Co[Q.sub.10] levels decreased with simvastatin treatment, but that the ratio of Co[Q.sub.10] to LDL cholesterol actually increased. One could argue that the ratio is more important than the absolute Co[Q.sub.10] concentration, but neither of those measurements necessarily correlates closely with tissue Co[Q.sub.10] concentrations. In animal studies, administration of lovastatin or pravastatin resulted in a significant reduction in Co[Q.sub.10] concentrations in myocardial tissue.

One wonders whether statin-induced heart failure will be the next "Vioxx." Perhaps, one day, the main question in a class-action lawsuit will be, what did the drug companies know and when did they know it, regarding the potential of statins to cause heart failure and the ability of Co[Q.sub.10] to prevent it.

Colquhoun DM, et al. Effects of simvastatin on blood lipids, vitamin E, coenzyme [Q.sub.10] levels and left ventricular function in humans. Eur J Clin Invest. 2005;35:251-258.

COPYRIGHT 2006 The Townsend Letter Group
COPYRIGHT 2006 Gale Group