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'CPET' -- An appropriate test for assessing/diagnosing ME/CFS?

Discussion in 'Diagnostic Guidelines and Laboratory Testing' started by alex3619, Jun 20, 2014.

  1. Dr.Patient

    Dr.Patient There is no kinship like the one we share!

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    I had a 1 day CPET done a year ago, and still suffering from the relapse that it caused. It is an unethical and harmful test. It should be banned for CFS patients.
  2. biophile

    biophile Places I'd rather be.

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    Yes, but psychiatry is also notorious for falsely attributing physical symptoms to psychiatric conditions. Many of the scales for depression and anxiety rely too much on counting physical symptoms towards diagnosis, which is why some of these questionnaires are essentially useless for patients with physical disease and are sometimes modified to account for this. Prevalence of co-morbid psychiatric disorder fundamentally depends on attribution of symptoms, whether it is a straight questionnaire or a semi-structured interview. Such circular reasoning has exaggerated the estimated prevalence of co-morbid psychiatric disorder in CFS. And only a few weeks ago I read a study on ICU survivors which diagnosed "depression" in the absence of psychological symptoms merely because physical symptoms were reported.
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  3. alex3619

    alex3619 Senior Member

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    The 2 day CPET produces problems for nearly all patients. What it shows though is disability. Many of us do not need to prove that. Some of us are put in the position by insurance companies or government agencies.

    I do not think CPET should ever be a mandatory test. Its primary use right now is research and for disability testing. One thing research has to do is a one year follow-up for harms assessment in a large cohort. One of its issues, I suspect, is it is only suitable for mild patients.

    More importantly, the 2 day CPET shows the reality of this disease. As a research finding its invaluable.

    I suspect that the way this will go is to submaximal testing. We only need to find that anaerobic threshold. For severe patients I am not even convinced that any effort is needed .... they could be near their limit just from being awake.

    Indeed, in 1993 I first encountered gas analysis testing for CFS (not ME back then). Metabolic testing like that is easy to do. At rest I was way below normal metabolic function. This combined with a CAT scan (HMPAO SPECT?) which showed low brain metabolic function was enough to show diminished capacity. The technology exists, but we are not using it.

    What we are heading toward though is blood testing. There are now quite a few abnormal results that are so far off normal they are highly useful. At the very least they can be potential confirmatory tests, as they can only be diagnostic if they show unique issues.

    I also suspect we might be able to use something like a muscle biopsy as a surrogate measure for CPET once more research is done. Our muscle cells function highly abnormally, producing way too much lactate under stress. Biopsy also has risks though. Indirect measures of muscle lactate would be better. If we can scan lactate (this technology exists) then we only have to exercise one muscle group. This might work in a two day test, though this requires a study to show this.

    The 2 day CPET is only the beginning, not the final word. Its important because it shows our reality.
    Last edited: Jun 26, 2014
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  4. alex3619

    alex3619 Senior Member

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    Again, show me the research. Severe deconditioning does not do what we see in ME. POTS frequently occurs in active people, often in those with genetic problems like EDS.

    Psychiatrists have not one shred of objective evidence for this claim. Depression is associated with physical symptoms. So is anxiety. Yet both are associated with a growing list of physical issues. Both are probably physical illness. Not one single psychosomatic disease has ever been proven. They have however been proven wrong, again and again, like in tuberculosis, diabetes, gastric ulcers, rheumatoid arthritis, lupus, and cancer, especially breast cancer.

    Nobody is doubting thoughts and behaviour can exacerbate disease. The issue is that nobody has proved they can cause disease. Nobody. "Psychosomatic" in the mid nineteenth century was about how thoughts affect disease. Then Charcot and later Freud (his student) came up with the idea that thoughts cause disease.

    Show me the properly researched data! Not speculation.

    This is how quackery works. Hypothetically, treat 1000 people. 100 improve on their own, by chance. Convince 10 they recovered from the treatment. Instant converts, giving anecdotal testimony, and potential recruits. What happened to the other 900? There is no substitute for scientific testing. None. There is also no substitute for having objective outcome measures. None. The LP proponents could organize proper scientific studies. They can also organize dubious studies. We wait. We will see.

    PS One caveat on behaviour. Destructive behaviours do exist. Sharing needles with other drug addicts has a high risk of contracting HIV. Behaviours contribute. The cause would still be HIV in this case.
    Last edited: Jun 26, 2014
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  5. kermit frogsquire

    kermit frogsquire *****

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    This is exactly my point - I don't know who Dr Snell is testing, but it sure isn't the people I know with ME/CFS. The people I know have abnormalities on a 1 day test. It is unthinkable that they could do another test on a second day. Dr Snell is trivialising this illness with very dodgy claims - from the data I have seen his there are serious potential bias issues with respect to not pushing the controls to exhaustion on the 1st day - and it doesn't matter what measure is used peakVO2 or VT RER, that issue is still a problem.

    On other message boards this topic has been discussed without a mob attack. Read some of the comments bleow -
    http://www.mecfsforums.com/index.php?topic=16831.0

    Yet Snell et al continue to post the claim - "The lack of any significant differences between groups for the first exercise test."
    http://ptjournal.apta.org/content/early/2013/06/26/ptj.20110368.short

    - who are these people that can exercise fine on day one? Also, if you read some of Snell's other papers, only 50% of his supposed "CFS/ME" patients had a fall in peakVO2 on day 2, they were completely normal.

    As I said above, this data is at complete odds with everyone I know who has ME - a single day exercise test is abnormal in ME patients and makes them feel so ill and produces such serious symptoms that a second test the very next day is unthinkable. Snell is trivialising this illness, either with extremely mildly affected patients, or given the issues with his data that I have previously raised, patients who are no different to couch-potato controls.

    We all have views on this, some people are in favour of exercise testing, some are not. Personally I think exercise testing can be good, but if we are going to study ME patients, let's use the data from the ME patients who have very serious abnormalities of day one, as the poster said above, some of these patients attended the research - yet Snell ignores them, and writes "lack of any significant differences between groups for the first exercise test".

    PS @Bob you posted a link to a message board, not a peer review artilce. I have read all Snell's peer review articles and all of them have the same methological errors mentioned before. Watts at VT, RER, it doesn't matter, those variable are all dependent on one thing, muscle fatigue - and when Snell is testing a single muscle group (cycle ergonometry) those variables should be worse in couch-potatoes on the second day. Why aren't they? The problem is as Dr Snell repeatedly hints - "On average, controls did slightly better on Day 2." In other words, they didn't try on the first day - and to confirm that we can see they don't reach their true HRmax%. HRmax% does not change from a single day of exercise, if you can reach a certain HRmax% on day two, you certain can on day one. Snell is either not pushing the controls on day one - bias - or they just aren't trying.
    Last edited: Jun 26, 2014
  6. justy

    justy Senior Member

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    Kermit frogsquire said:

    Do you really know it to be true that 'tens of thousands' of people have recovered using the Lightening Process? if this is the case then a link to the paper/website etc that shows this fact would be great. If that many people have recovered using LP then I might just part with the £650 and give it a go myself. In fact i'm amazed that Phil Parker isn't claiming the 'tens of thousands' figure himself. Well done you for claiming it for him!

    I am also interested in your assertion that the 'tens of thousands' of patients who recovered were 'predominantly' diagnosed by 'Cheny (sic), Klimas, Myhill, Bansal etc' (BTW who are the etc?)

    This is interesting for a number of reasons. One being that Cheney, Klimas and possibly etc all work in the States, where they do not have LP. That would mean that a 'predominant' amount of 'tens of thousands' of UK patients have either travelled to the states for diagnosis (show me the figures for this please, I was not aware our patient community was that rich or that mobile), and then went back to the UK and did the LP course and then recovered.

    Or perhaps you mean that a 'predominant' amount of 'tens of thousands' of patients who are US nationals and so diagnosed in their own country by their own doctors, such as Cheney Klimas, etc, have then travelled to the UK to do the LP and subsequently recover.

    This is the only explanation I can logically come up with after your assertion that 'tens of thousands' of patients recovered using the LP and that these are 'predominantly' the patients of top American researchers/physicians.
    (I hope you don't mind but I have decided that your list 'Cheny (sic), Klimas, Myhill, Bansal etc' may 'predominantly' include many more US CFS/M.E doctors/researchers than you state, as Myhill and Bansal are pretty much the only two in the UK and I thought for a long time about who 'etc' was and decided it must be Montoya, Peterson, Bell, Chia and perhaps De Meirleir).

    I bet lots of Cheney's patients are pissed off that they spent so much money on his consultations and treatments (we all know how expensive he is) when they found out that thousand of his other patients had been cured by spending no more than £650 on LP, plus the airfare and a couple of nights in a hotel.

    Cheers,
    Justy
  7. Valentijn

    Valentijn Activity Level: 3

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    Mild patients can perform somewhat normally on a one-off test. This is a good indication that the problem on day 2 is not due to inactivity or deconditioning, because those problems would show up on Day 1, not just on Day 2.

    As a moderate-to-severe patient with a lot of family support, I didn't even hesitate when my doctor wanted me to do a single CPET. And it has been extremely valuable in getting a waiver for a language test and in getting a disabled passenger parking permit. Each time the reviewer took one look at the results and was very happy to have a clear basis for making a favorable decision.

    Doctors and other professionals involved in assessing disability in any context know exactly what the CPET is, and have complete faith in it. If you know something which they don't, that casts doubt on it, maybe you should go ahead and write your revolutionary paper on the subject and amaze the world.

    Last and most importantly, Dr Snell and others engaged in exercise testing for ME patients are a doing a great service for us. They are using legitimate scientific methodology to document physiological pathology in an area of medicine in which they didn't start off having an interest, and in which biological researchers are often scorned and shut out. In the process, they have validated our symptoms and experiences, and are undermining decades of fraudulent and dishonest psychological research. I don't think we'll ever be able to thank them enough for the contributions they are making.
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  8. alex3619

    alex3619 Senior Member

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    @kermit frogsquire , you should go back and reread the comments at http://www.mecfsforums.com/index.php?topic=16831.0 again. Especially the one by Wally.

    The chief objection I saw was that ME patients cannot do this kind of testing. Yet I think that "recovered" patients, and mild patients, probably can. The most severe shouldn't due to health concerns.

    A second objection was based on using Fukuda criteria. Many of the patients studied anecdotally are probably Fukuda patients. Yet those patients who do not have PEM are not likely to have the 2 day CPET abnormalities. One thing though is that walk-in patients are more likely to be a self-selecting group, and referred patients are more likely to come from doctors who are not clueless. Were this testing to be done on a broad population like the CDC liked to investigate in the past (though perhaps not currently) then I think no significant results would be expected.

    What should be kept in mind is that most patients who get tested are probably mild patients, with some moderate, and only a few severe. Very severe patients would be completely excluded.

    Difficulty of the test is also dependent on a patient's capacity. Someone more sick would not have to do very much for this test. However they are the ones more likely to have severe relapse, as they are probably living closer to the metabolic edge.
    Last edited: Jun 26, 2014
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  9. kermit frogsquire

    kermit frogsquire *****

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    @Valentijn and @alex3619 - that is not what Snell wrote - he said there was "The lack of any significant differences between groups for the first exercise test." He didn't say these were "recovered" patients or "mild patients".

    At the very least comments like Snells do more harm than good. Since patients have reported that they were included in research and couldn't do a second day of testing, why does Snell not make it absolutely clear in his published papers that many ME patients are so ill they have absormal 1 day tests? And since these patients are the most obviously ill, where is the paper describing these patients? Surely a paper on those patients would help the case of ME more? Not mild abnormalities that misrepresent that we can ALL exercise normally on day 1.

    Only Snell has done these two day tests and I feel very uncomfortable about his claimed findings when there are so many problems with his results for day 1 of the healthy controls.
  10. Valentijn

    Valentijn Activity Level: 3

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    I can't figure it out. Are you a liar in order to troll or do you just not read anything?

    Another group has reproduced the same results on the 2-day CPET. The link was already provided to you directly.

    Stop trolling, and stop lying. And if you aren't willing to read the research when it's handed to you, you shouldn't be engaging in debate with reasonable people who take the time to read your crap.
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  11. alex3619

    alex3619 Senior Member

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    Incorrect. Many doctors have done these two day tests. Now another group has published on this. That publication is why I have been pushing CPET, I waited till someone not connected with Workwell published. That is what is needed in these cases - independent research.
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  12. kermit frogsquire

    kermit frogsquire *****

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    Another group ... okay, I'd like to see that! Have you got the link to the full paper? The only links I can find previously are to Phoenix Rising forums, these are not peer review medical papers. I don't understand the problem with giving me the link?

    Look, we all want better research on ME. We all accept that people with an abnormal 1 day CPET are really really sick. - Why not chose them for further research studies? If they are clearly the sickest, they also have the clearest chance of finding true biomarkers that will help everyone sort out this mess.

    I would quite happily see a 1 day CPET test used to select patients for research rather than "mild" or "recovered" cases. AIDS was not discovered in the early stages of mild symptoms of HIV, it was discovered in a full blown AIDS patient. We need clarity.
  13. alex3619

    alex3619 Senior Member

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    I do not disagree with the point that the most sick are the people to be studying . This however cranks up the cost enormously. Our researchers have had so much trouble getting a little money, its only now that we are starting to see more research on the most ill patients. Its way past time.

    My local research group at Griffith University have, I think if I recall right, been talking about getting a medical van that can travel to housebound patients. That would be something. They also do state of the art immune testing of the kind that doctors can only dream about.
  14. kermit frogsquire

    kermit frogsquire *****

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    You read the posts on the other forum. There were plenty of CFS/ME patients who had abnormal 1 day CPET tests. Snell et all just dismissed their results. I don't think it will add costs.

    Also, is this the paper from the other group to which you refered?

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004422/

    I've read it before. It adds nothing to the debate. CFS patients reduced their peakVO2 on day 2 by almost exactly the same amount as the reduction in Work %. As I said, all this actually proves is that the CFS patients didn't do as much. Whether this is important is dependent on one thing - can we see this same effect in very sedentary healthy controls who actually exercise to their limit on day 1?

    Since this paper failed to test healthy controls, it adds little to the debate.

    What I have contended is that the Snell paper did not adequately prove that health controls who were very inactive/bed rested, did not show a drop in VO2 on day 2 because they did not appear, and further there was no evidence to show, that they had exercised maximally on day 1. Further the only objective measure (HRmax%) showed that the controls did not exercise maximally on day 1 - thus the test is invalid as only maximal exercise results in inflammatory cascade.

    What I have said is that of course very inactive people, to the point of a lot of bed rest, will show a drop on day 2. So the paper by the other group just confirms that. It is the healthy controls bit that needs repeating, not the ME/CFS side of the study.
    Last edited: Jun 26, 2014
  15. Bob

    Bob

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    I provided a link to a forum thread that contained a link to the latest Snell paper in the opening post.

    This is the latest Snell paper:
    http://ptjournal.apta.org/content/early/2013/06/26/ptj.20110368.abstract


    I'll assume that you haven't any evidence to support that claim, seeing as you've failed to provide any evidence for any of your previous pet theories.
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  16. alex3619

    alex3619 Senior Member

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    I had already provided the link, here is another one to replication research:

    http://www.ncbi.nlm.nih.gov/pubmed/24755065

    One key thing is they show about half of the patients have a bad result on even a one day CPET. The two day test is emphasized because the profile does not fit deconditioning theories.
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  17. kermit frogsquire

    kermit frogsquire *****

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    @Bob and @alex3619 I don't think you have read my posts, I posted a link to both those papers myself.

    As I said just a moment ago,

    Furthermore, since I have robustly shown, papers previously posted, that severe inactivity produces a marked inflammatory cascade from maximal exercise - we can't just use sedentary controls, we need really sendentary people as controls. Rest is not benign. Are we testing ME or the effects of rest?

    Ask any cardiologist and they will tell you that CPET testing is fraught with problems, and the results are often of questionable significance - I don't think we should be wasting vital money on something others aren't going take notice of. Someone asked, why isn't anybody interested in this outside of sports medicine - CPET testing is not great and has a many many problems regarding accuracy of interpretation.
  18. alex3619

    alex3619 Senior Member

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    Sixty five years of CPET testing includes probably hundreds of thousands of super sedentary people, including heart attack patients, and heart failure. Yet none show our abnormalities so far as anyone has been able to determine. Maybe there is data there locked away in all those databases, or maybe not.

    Further, most CFS patients tested are not bed bound. Bed bound patients typically cannot be included. So that is not an issue. To be included on this kind of study you have to be able to travel, and exercise, and travel home, then repeat it the next day. Bed bound patients cannot do that.

    So far as controls are concerned, I would like to see people with other related disorders as control groups, though I realize there may be big issues with recruiting.
  19. Valentijn

    Valentijn Activity Level: 3

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    Work at peak is irrelevant to your argument. It doesn't indicate less effort or invalidate the measurements which show objective maximal effort. Respiratory Exchange Ratio of 1.1 is accepted universally as showing maximal effort, as that is the point where the usual energy source basically is failing. It has nothing at all to do with how hard someone is trying, and everything to do with the physiological limitations of the body at that time.

    Thus the data indicates that ME patients, when putting forth their best effort, achieve a much lower than expected VO2max at maximal effort. If they'd been biologicaly capable of exerting more effort, their RER (or RQ) would have been under 1.1 at peak.

    I think this is a pretty simple concept, at least it should be for an ME patient. One person hits their limits at one level of exertion, and another person hits their limits at a different level of exertion. This is true in normal people, in elite athletes, and in ME patients. For healthy, sedentary, deconditioned controls, that limit will be about the same on the 2nd day, or slightly higher. For rested ME patients with a similar level of deconditioning, they will have a similar limit to the controls on day 1, but then show a drastic decline in work ability on Day 2, which is also reflected in VO2max.

    RER or RQ is the biological proof that the patient has exerted maximal effort.
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  20. Bob

    Bob

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    We've already had this discussion...
    And you've already observed that the patients tested by Dr Snell and colleagues were clearly not bed-bound or excessively sedentary.
    So why would you want bed-bound controls?
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