Is there a Blood Test for Post-Polio Muscle Pain?

Richard L. Bruno, HD, PhD
Director, International Centre for Polio Education

Question: Recently I had arm and chest pain. I went to the ER. The only abnormal blood tests showed high C-reactive protein and high creatine kinase. My blood pressure and cholesterol are normal, I have never smoked and I'm thin. My EKG showed that I hadn’t had a heart attack. Could high CRP and high CK be related to PPS?

Dr. Bruno’s Response: C-reactive protein is a blood marker for inflammation somewhere in the body. High CRP can be seen with type 2 diabetes, autoimmune diseases and cancers. Could inflammation somewhere in your body, as indicated by your elevated CRP, be related to PPS? Fifty consecutive patients evaluated at The Post-Polio Institute had CRP measured. The patients were on average 59 years old and 55% were women. Only 13% had an elevated CRP, 66% of whom were men. CRP was on average nearly three times the normal value. However, there was no significant difference between those with high versus normal CRP on self-ratings of daily fatigue, difficulty with self-care or ability to perform activities inside or outside of the home. So, there is no evidence that elevated CRP or inflammation is related to PPS, either to post-polio fatigue or difficulty in functioning.

Recent studies have found that elevated CRP can be related to having a heart attack or stroke. The theory is that a bacterial or viral infection (although definitely not a poliovirus infection) somehow inflames arteries and causes them to clog. Our 1985 National Survey found no more heart disease or high blood pressure in polio survivors than in the general population. But two studies found that 5% more male post-polio patients had abnormally elevated cholesterol as compared to the general population. In one study only 33% of those with high cholesterol had been given a cholesterol- screening test by their local doctor and not even 25% were on cholesterol-lowering medications, like the statin drugs such as Lipitor, Zetia and Zocor. This is not good, since reducing “bad” cholesterol reduces heart attack risk and may increase survival even after having a first heart attack.

Statins provide a connection between elevated CRP and CK in polio survivors. CK is an enzyme released when muscle is damaged; only 0.5% of anyone taking a statin develops muscle damage, which causes muscle pain (especially in the calves), muscle weakness and an increase in CK. Even without muscle breakdown or an elevated CK, some polio survivors report muscle pain or weakness when taking a statin, usually one of the older statins like Lipitor.

But polio survivors can have an elevated CK without taking a statin. Two studies found that 40% of polio survivors had abnormally elevated CK, with men having significantly higher CK than did women. In one study CK increased with the number of steps polio survivors walked in a day. In 50 Post-Polio Institute patients, 21% had abnormally elevated CK levels (on average about 33% higher than normal) with men also having higher CK than women. But, as with CRP, there was no significant difference between those with high and normal CK on self-ratings of daily fatigue, difficulty with self- care or the ability to perform activities inside or outside of the home. However, an elevated CK may mean that polio survivors are making their muscles work too hard and are causing them to break down.

So, neither CRP nor CK is related to fatigue or loss of functional abilities in polio survivors. However, all polio survivors need to have their cholesterol and CRP measured to assess heart disease risk.

And since an elevated CK indicates muscle breakdown, either from taking a statin or from muscle overuse, polio survivors should have CK measured before taking a statin. If you are worried about possible muscle weakness or breakdown with the statins, ask your doctor about using older medications, like slow-acting niacin or bile acid sequestrants, or newer drugs such as Zetia and Zocor. Besides medication, polio survivors need to eat high fiber foods, reduce saturated fat, treat high blood pressure and stop smoking to keep their tickers ticking.

(For more information, see the topics “Drugs and Medications” and “Muscle Pain” in the Index of the ENCYCLOPEDIA of POLIO & PPS).