Dr. Paul D. Thompson, MD, explains which muscle symptoms on a statin call for stopping it and contacting a doctor, and how a rare immune reaction to statin treatment damages muscle and is diagnosed.
Muscle Weakness on a Statin: Warning Signs and Autoimmune Myopathy
Jump To Section
- Muscle symptoms that need prompt attention
- An immune reaction against HMG-CoA reductase
- Diagnosis with a blood test
- Full Transcript
Muscle symptoms that need prompt attention
Muscle weakness is the statin symptom to worry about, cardiologist Dr. Paul D. Thompson, MD, tells Dr. Anton Titov, MD. People with weakness, especially profound weakness, should stop the statin and get in touch with their doctor right away, he says. A lot of pain on a statin can also be a sign of muscle breakdown.
He describes this as rare, one in 5,000 to one in 10,000 statin-treated people, but something to be aware of.
An immune reaction against HMG-CoA reductase
The cause lies in how statins work, Dr. Thompson explains. Statins bind to HMG-CoA reductase, the enzyme that makes cholesterol, and make it inoperative. Some people treated with a statin then make what he calls an allergy against the enzyme and start attacking their own muscle. The process does not stop, he says, and it often does not go away without suppressing the immune system.
Diagnosis with a blood test
Statin-associated autoimmune myopathy is diagnosed with a blood test. Dr. Thompson says doctors can measure anti-HMG-CoA reductase antibodies in the blood, and finding them makes the diagnosis.
Full Transcript
Dr. Anton Titov, MD: Muscle weakness on a statin, statin-associated autoimmune myopathy. You were first author of a review of statin side effects. On your blog you wrote that ordinary statin muscle symptoms do not usually cause muscle weakness. Weakness, or symptoms that persist after the statin is stopped, can signal a rare autoimmune muscle disease. Professor Thompson, which muscle symptoms on a statin need urgent medical attention? How is statin-associated autoimmune myopathy diagnosed and treated?
Dr. Paul D. Thompson, MD: The thing to worry about with a statin is that if you have muscle weakness, especially if it is profound, you need to stop the statin and get in touch with your doctor right away. Also, a lot of pain on a statin can be a sign of muscle breakdown. So those are the things I tell people to worry about.
Dr. Paul D. Thompson, MD: Now, does it happen? Rarely. One in 5,000, one in 10,000 statin-treated subjects, but it is something you at least want to be aware of.
Dr. Paul D. Thompson, MD: If you really have muscle symptoms of weakness, stop the statin and talk it over with your doctor right away. Now, it is due to the fact that statins bind with HMG-CoA reductase. HMG-CoA reductase is the enzyme that makes cholesterol.
Dr. Paul D. Thompson, MD: Statins bind to it. They make it inoperative. Some people make an allergy against HMG-CoA reductase once they are treated with a statin, and they start attacking their own muscle with this protein, with this allergic protein.
Dr. Paul D. Thompson, MD: It does not stop. It does not go away often without suppressing your immune system. How is it diagnosed?
Dr. Paul D. Thompson, MD: We actually can measure anti-HMG-CoA reductase antibodies in the blood. So it is diagnosed by a blood test showing that you have antibodies.