study of statin myopathy with RRF

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Statin-associated myopathy with normal creatine kinase levels.

PS, Haas RH, Bannykh S, Hathaway S, Gray NL, Kimura BJ,

Vladutiu GD, England JD; Scripps Mercy Clinical Research Center.

BACKGROUND: Muscle symptoms in patients who are treated with statins

and have normal creatine kinase levels are not well understood.

OBJECTIVE: To report biopsy-confirmed myopathy and normal creatine

kinase levels associated with statin use.

DESIGN: Case reports from preliminary analysis of an ongoing

clinical trial.

SETTING: Clinical research center in a community hospital.

PATIENTS: Four patients with muscle symptoms that developed during

statin therapy and reversed during placebo use.

MEASUREMENTS: 1) Patients' ability to identify blinded statin

therapy and 2) standard measures of functional capacity and muscle

strength.

RESULTS: All four patients repeatedly distinguished blinded statin

therapy from placebo. Strength testing confirmed weakness during

statin therapy that reversed during placebo use. Muscle biopsies

showed evidence of mitochondrial dysfunction, including abnormally

increased lipid stores, fibers that did not stain for cytochrome

oxidase activity, and ragged red fibers. These findings reversed in

the three patients who had repeated biopsy when they were not

receiving statins. Creatine kinase levels were normal in all four

patients despite the presence of significant myopathy.

CONCLUSION: Some patients who develop muscle symptoms while

receiving statin therapy have demonstrable weakness and

histopathologic findings of myopathy despite normal serum creatine

kinase levels.