Statin Treatment May Disclose Metabolic Muscle Disorder

Taking cholesterol-lowering drugs in the statin family (such as atorvastatin, simvastatin and others) can reveal a previously hidden metabolic muscle disorder, say researchers from several collaborating institutions who published results online May 2 in Muscle & Nerve. The findings may also have implications for those who already know they have a metabolic disorder or are carriers for one and need to take statins.

When MDA-supported Georgirene Vladutiu at the State University of New York at Buffalo and colleagues performed genetic testing on 110 people taking statins and experiencing muscle pain, weakness or other symptoms, they found considerably more underlying metabolic deficiencies than they found in people taking statins who didn’t have muscle symptoms.

Among people taking statins who experienced muscle symptoms, 10 percent had at least one previously undiscovered mutation for CPT2 deficiency or phosphorylase deficiency, or two mutations for myoadenylate deaminase deficiency. Among those with no muscle symptoms, only 3 percent had these mutations.

The investigators hypothesize that statins may trigger symptoms of underlying, pre-existing conditions in muscles already compromised (even subtly) by a metabolic deficiency.

Vladutiu says she hasn’t fully explored the implications of these findings for people who already know they have a muscle-damaging condition, but she recommends a cautious approach with close monitoring of symptoms and lab values, such as serum creatine kinase (CK) levels, a rough indicator of muscle damage.

She cautions that the new study only applies to three metabolic muscle diseases, although her group plans to study other disorders soon.

“So far we have performed a pilot study with these three disorders and are trying to get at other genetic risk factors for the development of a statin myopathy,” Vladutiu said.

“We certainly would not want to frighten anyone into not taking statins, including people with pre-existing muscle abnormalities, because they are important drugs in the treatment of a number of conditions. But there must be a balance, and doctors need to be vigilant in monitoring risk factors in their patients. If they give statins to a higher risk patient, then they have to monitor dosage, symptoms and serum CK frequently.”