ck/cpk increasing every month; why?

[petepat]

I am hoping that you may be able to help me with some information.  In August my doctor tested my ck/cpk level because I was taking Lipitor and I had experienced some muscle pain.  My ck/cpk level was 211 u/l so he decided to take me off of the drug and test me again.  Three months later in November another test showed that the level was at 332 u/l.  I had been taking Niacin pills, so he told me to stop those and test again.  Just recently (December 15th) I was tested again and the ck/cpk level was up to 361 u/l.  He ran a test of my myoglobin and troponin to see if it was heart related; both results were good.  I have met with a surgeon to schedule a muscle biopsy.  I am wondering if you can shed any light on this for me.  Since August my ck/cpk scores seem to be gradually but steadily increasing at a rate of about 30-40 u/l per month.  I do have some muscle weakness/pain in my right shoulder/upper arm area, but it is very slight, not bad at all.  I am a 57 year old male.  Do you think that I should see a specialist (e.g. neurosurgeon or other?) before I get the muscle biopsy?  Also, they are planning on doing the muscle biopsy on my left thigh.  If I have been experiencing the muscle weakness in my right arm/shoulder area (although it is slight)is that the place where they should be doing the biopsy or will a biopsy of the thigh muscle tell us what we need to know about what is going on- if anything?  Any help or advice you can give would be appreciated.  Thanks.

[CCF-Neuro-M.D.-CS]

It would be reasonable to have an evaluation with a neurologist before proceeding. They can examine you and review your history. They may want to perform an EMG test (muscle and nerve test) to help determine what is occurring. Also, the last change in your CK is not dramatic, and may be within the normal variation for the lab. Let me explain, when a test is performed on the same sample at two different times, or on two different machines there is typically same variation in the result. This is the machines standard deviation. Therefore, the change from 332 to 360 may not be significant. Second, your physical activity ( excercising or hard work) prior to the test can also change the results.

Regarding the location of the biopsy, we typically try to biopsy a region of muscle which is mild-moderately involved if possible. The EMG test can be used as a guide to which muscle can be biopsied.  Good luck.

[petepat]

Thanks much for the advice.  I contacted my physcian and he agreed that it would be a good idea to consult with a neurologist before getting the biopsy.