Diet Can Trigger Severe Myopathy Often Blamed on Statins

— Case report showed woman didn't take statins or supplements

MedicalToday

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Immune-mediated necrotizing myopathy with antibodies against the enzyme targeted by statins, HMG-CoA reductase, was found in a woman with with their statin component.

The 57-year-old had progressively-serious weakness over 2 weeks and was tested with electromyography, muscle biopsy, the EUROIMMUN assay for possible myositis-associated antibodies, and finally an ELISA for anti–HMG-CoA reductase antibodies that turned out to be strongly positive.

Finding no obvious source for these, Ariane Barbacki, MD, of Sir Mortimer B. Davis Jewish General Hospital in Montreal, and colleagues determined that the woman's habit of eating at least 2 cups of Camargue red rice each day in the months leading up to symptom onset was to blame. While containing no known statin component — unlike red yeast rice, which the Camargue variety superficially resembles but which does contain a statin compound — that amount of Camargue rice would provide about 2 g of phytosterol that can reduce LDL levels by inhibiting HMG-CoA reductase "through a statin-like mechanism."

"We thus believe that this case supports the hypothesis that diet may be the source of statin exposure for patients who have immune-mediated necrotizing myopathy with anti–HMG-CoA reductase antibodies and no recognized exposure to a statin," the researchers concluded in the Annals of Internal Medicine. "To our knowledge, this is the first reported case with such a clear exposure."

After initial treatment with prednisone and then monthly immunoglobulin treatments, her weakness and myalgia declined, Barbacki's group noted. But her symptoms did not entirely resolve: "One year after the disease began, the patient still had dysphagia that required a pureed diet and continued to receive monthly intravenous immunoglobulin therapy."

Disclosures

Barbacki disclosed no financial relationships with industry.

One co-author disclosed consulting and honoraria from Abbvie, Pfizer, Roche, and Novartis.

Primary Source

Annals of Internal Medicine

Barbacki A, et al "Immune-mediated necrotizing myopathy and dietary sources of statins" Ann Intern Med 2018; doi:10.7326/L17-0620.