idiopathically elevated CK patient (paging Rheum?)

[DrMetal]

Approach to asymptomatic creatine kinase elevation - PMC

What's your approach to the idiopathically elevated CK patient, who's entire workup (including muscle biopsy, genetic testing) is negative? Patient's main complaint/symptom is exercise intolerance.

Would you consider a low dose daily steroid (Prednisone 5, or 10 mg Daily), to see if it alleviates symptoms ?

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[dozitgetchahi]

Approach to asymptomatic creatine kinase elevation - PMC

What's your approach to the idiopathically elevated CK patient, who's entire workup (including muscle biopsy, genetic testing) is negative? Patient's main complaint/symptom is exercise intolerance.

Would you consider a low dose daily steroid (Prednisone 5, or 10 mg Daily), to see if it alleviates symptoms ?

How high is the CK? And what exactly do you mean by “exercise intolerance”?

Isolated CK elevations don’t usually raise my eyebrow unless 1) the CK is consistently over 1000, without other symptoms or 2) the CK is more mildly elevated, but the pt has CLEAR manifestations or lab evidence of some sort of inflammatory myositis, metabolic myopathy, etc etc.

Most of these “mildly elevated CK” consults consist (after workup) of reassuring the patient that there is nothing actually wrong. Studies show that CK levels of 500+ can sometimes be totally physiologic, especially in men (particularly African American men).

Check an aldolase too.

Make sure the patient isn’t doing cocaine or meth, or guzzling coffee. I’m also assuming the pt isn’t on any prescription medication associated with myopathy (colchicine, statins, other cholesterol meds, etc etc).

If the patient has no real exam manifestations of inflammatory or metabolic myopathy (rashes, dyspnea, dysphagia, or the rest of the ANA-associated symptom list) and top to bottom workup (including ENA panels, myositis panel, etc etc…which if you’ve gotten to the point of a muscle biopsy, metabolic genetic testing, etc you’ve almost certainly done) is negative, then my usual next move is to discharge the patient from clinic. Prednisone won’t help these “exercise intolerance” people (I’ve seen it done by PCPs, never with any benefit) and long term prednisone use is going to cause muscle wasting and make symptoms worse anyway.

If you want to torture the neurologists at your local tertiary center, you can send this patient for a neuromuscular consult. But probably 99% of these “exercise intolerance, elevated CK, negative workup” people have fibro, or something similar. Some tiny fraction maybe have a metabolic issue which has not been categorized.

(The last patient I saw like this had a million dollar workup between myself and a neuromuscular guy at the local tertiary center. At the end of the day, he had fibromyalgia, and sleep apnea, and nothing else aside from a spurious positive ANA of no consequence.)

 

[NewYorkDoctors]

well if I were referred this patient for "exercise intolerance" and I saw elevated CPK (not knowing any other workup), I would think about mitochondrial myopathy and do a CPET test. But noninvasive CPET does not really lead to the diagnosis. The patient would need invasive CPET with the A line and q2 minute ABGs / lactate to calculate A-VO2 difference .

But I would first do noninvasive CPET, try to get a good effort out of the patient, find decreased peak VO2 and decreased OUES , have a negative cardiac workup, then would send to my academic colleagues for the invasive CPET testing.

though that algorithm ultimately leads to the neuromuscular specialist anyway for EMG, muscle biopsy, genetic testing etc...

though this is not the exact scenario you outlined. but just wanted to point out how I would have started this evaluation tarting from chief complaint of "exercise intolerance."

 

[DrMetal]

How high is the CK? And what exactly do you mean by “exercise intolerance”?

Isolated CK elevations don’t usually raise my eyebrow unless 1) the CK is consistently over 1000, without other symptoms or

1100-1200s, exercise intolerance = extreme fatigue and soreness lasting 1-2 days after a light workout (walking fast on a treadmill for 15-20 minutes, light weightlifting). It bothers the patient, he's an otherwise young fit person, wants to workout. All of the above checked and negative.

So not even a light 5 or 10 mg daily prednisone? Would you try it to see if any benefit? I agree to be cautious, side-effects of steroids notwithstanding. I figure we have plenty of patients (chronic asthma, COPD, transplant patient) on a chronic low dose prednisone, albeit they're a lot older and less of a life expectancy. Maybe try it in these cases for chronic inflammatory conditions?

 

[dozitgetchahi]

1100-1200s, exercise intolerance = extreme fatigue and soreness lasting 1-2 days after a light workout (walking fast on a treadmill for 15-20 minutes, light weightlifting). It bothers the patient, he's an otherwise young fit person, wants to workout. All of the above checked and negative.

So not even a light 5 or 10 mg daily prednisone? Would you try it to see if any benefit? I agree to be cautious, side-effects of steroids notwithstanding. I figure we have plenty of patients (chronic asthma, COPD, transplant patient) on a chronic low dose prednisone, albeit they're a lot older and less of a life expectancy. Maybe try it in these cases for chronic inflammatory conditions?

Prednisone is unlikely to be helpful because what you’re describing sounds much more like a metabolic myopathy than inflammatory myositis. Reducing inflammation (which is what prednisone does) isn’t going to help a mitochondrial/metabolic defect.

Is the CK elevated at baseline, or just after exercise?

If you want to work up further, consider repeat muscle biopsy. Or make sure the previous biopsy gets read by a good tertiary center (CCF is a good choice), not some local yokel pathologist. Could also consider getting an MRI of the proximal thigh or arm to see if there are inflamed regions of muscle. This potentially helps guide a repeat biopsy to ensure inflamed tissue gets biopsied (doesn’t help if just metabolic). Does pt describe a lot of myalgias?

If the pt hasn’t seen a neuromuscular specialist, they should. Does he have a family history of this sort of issue?

 

[DrMetal]

Prednisone is unlikely to be helpful because what you’re describing sounds much more like a metabolic myopathy than inflammatory myositis. Reducing inflammation (which is what prednisone does) isn’t going to help a mitochondrial/metabolic defect.

Is the CK elevated at baseline, or just after exercise?

If you want to work up further, consider repeat muscle biopsy. Or make sure the previous biopsy gets read by a good tertiary center (CCF is a good choice), not some local yokel pathologist. Could also consider getting an MRI of the proximal thigh or arm to see if there are inflamed regions of muscle. This potentially helps guide a repeat biopsy to ensure inflamed tissue gets biopsied (doesn’t help if just metabolic). Does pt describe a lot of myalgias?

If the pt hasn’t seen a neuromuscular specialist, they should. Does he have a family history of this sort of issue?

Yes, CK elevated at baseline. Not a lot of myalgias described at rest (or when not working out), only affect 1-2 days after a workout). We may go MRI/repeat biopsy route.

So what do you do for these patients, even if you can establish a diagnosis? Supposed one of the genetic mitochondrial tests returns positive. Basically still reassurance and counseling, right?

 

[dozitgetchahi]

Yes, CK elevated at baseline. Not a lot of myalgias described at rest (or when not working out), only affect 1-2 days after a workout). We may go MRI/repeat biopsy route.

So what do you do for these patients, even if you can establish a diagnosis? Supposed one of the genetic mitochondrial tests returns positive. Basically still reassurance and counseling, right?

It depends. There are a bazillion different varieties of metabolic myopathies - some of them have specific treatments ranging from dietary supplements to specific medications etc. Some of them don’t. As a rheumatologist, I don’t really get into treating these - that’s usually the arena of neuromuscular or medical genetics.