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Clinical Trials Showing 2 day CPET Tests Diagnostic or Biomarker?

J

joshualevy

Senior Member
Messages
158
I've seen several posts (here and elsewhere) suggesting that a 2 day CPET test can be used to confirm a ME/CFS diagnosis, but I've also seen posts (for example, by Jonathan Edwards) that say that is not true.

I looked at clinical trials of 2 day CPET tests, and I see some trials that show a statistically significant difference between people with ME/CFS and people without, but I have not seen tests that show a diagnostic difference in results. What I see is much like measuring height to separate men from women: sure there is a statistically significant difference, but there are so many tall women and short men, that you can not do a measurement and say "this is a man" or "this is a women" based on their height. So has anyone seen such a CPET study which divides people into have ME/CFS and don't? I'm OK with a relatively low accuracy. If the test is only right 90% of the time, that is OK with me, but I have not found a study even that good. Does anyone know of one?

My second question is, has anyone seen any 2 day CPET tests that can be used as a biomarker. By this, I mean that it can be used to measure how serious a person's ME/CFS symptoms are. People with worse symptoms will have worse 2 day CPET results and visa-versa. The same person will do worse on a 2 day CPET test on a day when their symptoms are worse. I could not find any such tests, and I assume that they can not be done because people with worse symptoms can not do a 2 day CPET test, so there is no comparison data. But if anyone knows of any such results, I'd be interested.

Thanks.
 
Rufous McKinney

Rufous McKinney

Senior Member
Messages
13,388
J

joshualevy

Senior Member
Messages
158
Rufous, I looked through the studies at Workwell, but (as you suspected) there were no studies that showed a 2 day CPET test could be used as a diagnostic or as a biomarker.

One had a very promising title: Post-exertional symptoms distinguish Myalgic Encephalomyelitis/Chronic Fatigue Syndrome subjects from healthy controls but it did not use 2 day CPET to distinguish anything. It used symptoms generated by a 2 day CPET test (and only symptom counts at that).

Another study Post-exertional symptoms distinguish Myalgic Encephalomyelitis/Chronic Fatigue Syndrome subjects from healthy controls shows the overlap between people with ME/CFS and controls. The tables on page 252 (and one on 253) make it clear that the test can not be used to distinguish between the two groups.

Does anyone know about any other studies?
 
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