Statin-induced Myopathy and Ubiquinone Levels in Serum - Results from a Prospective, Observational Study

It has been suggested that an impaired ubiquinone (Q10) synthesis may be responsible for muscular side effects caused by statins. The primary aim of this study was to investigate whether low Q10 levels in serum could be used as a marker to predict the risk of developing statin-induced myopathy. The secondary aim was to compare the change in Q10 levels during statin treatment and differences between men and women. Serum samples from a prospective, observational study in statin-treated patients who were thoroughly followed regarding muscular symptoms were used. In this cohort, 16 developed myopathy and 126 had no muscular symptoms related to statin treatment. Q10 levels were measured with a novel LC-MS method at baseline and after 2 months of statin treatment. Q10 levels showed no correlation with the risk of developing statin-induced myopathy. Individuals with low levels, Q10 < 200 ng/ml, at baseline had no increased risk of developing myopathy. In consistence with earlier reports, we showed that Q10 levels were reduced by 30% during statin treatment. There was no significant difference in the reduction between patients with or without myopathy. Women had approximately 30% lower Q10 levels compared to men both before and after treatment. In this study, there was no association between Q10 levels at baseline and statin-induced muscular side effects during a 2-month follow-up period, and our results indicate that Q10 levels in serum is not a useful marker to predict statin-induced myopathy.