Severe ME Day of Understanding and Remembrance: Aug. 8, 2017
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Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy

Discussion in 'Latest ME/CFS Research' started by A.B., Aug 8, 2017.

  1. A.B.

    A.B. Senior Member

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    Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy controls following repeated exercise: a pilot study.

    https://www.ncbi.nlm.nih.gov/pubmed/28782878
     
  2. Valentijn

    Valentijn Senior Member

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    So CFS and MS do worse compared to their healthy matched controls on a single CPET, and on the 2nd CPET as well. But the MS patients do a bit better on their 2nd CPET compared to their first one, while CFS patients do worse. Nothing new, but it's always great to see independent replication.
     
  3. A.B.

    A.B. Senior Member

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    Surprisingly to me CFS patients did a little better on VO2 and VO2max on the second day, but worse on other measures. It seems that measuring the drop in function on the second day isn't that straightforward. Maybe it depends on the exercise protocol used, activity level on previous days, and things like that. MS patients were also an average of 19 years older than the CFS patients making direct comparison difficult (both had age matched control though).
     

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  4. ash0787

    ash0787 Senior Member

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    similar been done before, they could try measuring relevant by-products / metabolites after 30 minutes of exercise or try using a high grade thermal camera to look at heat generation / distribution / circulation etc
     
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  5. Simon

    Simon

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    Needs a bigger study to replicate these findings, but I think this is the first study to show other diseases are different (outside cardiopulmonary ones), a key step in showing these findings are specific to mecfs.
     
  6. Valentijn

    Valentijn Senior Member

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    Full text at http://sci-hub.io/10.1111/cpf.12460 - It's a nice read, even if not understanding the technical bits. They really seem to understand what ME is, that PEM is a defining symptom, and the implications of exercise recommendations.

    As @A.B. said above, VO2max didn't drop, just max workload and heart rate at maximal exertion. It seems like objectively determined maximal exertion was reached, with an actual Respiratory Exchange Rate (RER) showing exhaustion of aerobic energy production. So the lower max workload wasn't due to slacking off:
    vo2max.jpg
    ETA: Note that the MS patients are 20 years older than the CFS patients. So they're not necessarily in worse shape, and values can't be directly compared between those two groups.

    Replication is really essential for the two-day CPET. Yes, it's been done before but it's always in small numbers due to the expense. And it's really great to have different teams replicating independently of each other - it makes it so much harder for the psychosocial quacks to dismiss the evidence when it's coming from 4 or 5 different countries.

    I'd also point out that this is explicitly a pilot study. Hopefully we'll be seeing something bigger and more elaborate in the future from them :D
     
  7. John Mac

    John Mac Senior Member

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    There was a press release about this study a couple of months ago.
    Discussed here:
    http://forums.phoenixrising.me/index.php?threads/distinguishing-cfs-new-zealand-research.51357/

    "To find out more, Dr Hodges is completing another trial examining the physiological differences in repeated maximal exercise at 48 hours and 72 hours. “We will be taking blood samples to examine markers of inflammation, blood pressure and heart rate, asking questions about fatigue, and participants will be asked to do simple computer tasks to examine cognition, as well as ultrasound to measure arterial stiffness, and the cycle test to examine anaerobic threshold. All tests will then be repeated at either 48 hours or 72 hours later.”
     
  8. Londinium

    Londinium Senior Member

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    No, no, please tell me more about how it's all deconditioning...

     
  9. *GG*

    *GG* Senior Member

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  10. JaimeS

    JaimeS Senior Member

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    Well done, pilot study. Now, aim for more people!
     
  11. daisybell

    daisybell Senior Member

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    I don't know how many people actually had blood taken - I was a participant in this trial and didn't get blood drawn...
     
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  12. Denise

    Denise Senior Member

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    I'd be interested to know what form of MS the participants had and whether that made a difference in their test results.
     
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  13. Snow Leopard

    Snow Leopard Hibernating

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    I believe that the reason why patients were able to reproduce their VO2Peak because they didn't exercise to VO2Max. This is also the reason why the healthy controls were able to increase their VO2Peak, because they didn't reach VO2Max either. VO2Max will occur much higher than 150-160bpm in people with an average age of 37, it occurs well past the ventilatory/anaerobic threshold. The lower performance of the MS group is also likely to be due to the much higher average age (55).

    This is why we are seeing some variance between studies...

    Here are the (cited) age norms for fitness from Heyward & Gibson:
    fitness norms Heyward & Gibson.jpg

    My own experience of the 2 Day test is that it is VERY HARD and leads to more severe symptoms for weeks. My performance was "good" on the first day and borderline "fair-poor" on the second day according to the table.

    Also, why are no RER values provided?
     
    Last edited: Aug 8, 2017
  14. Snow Leopard

    Snow Leopard Hibernating

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    This explains the difference in protocol (eg exercising only to the ventilatory threshold) experienced by people in the participating in the follow up study:
    http://forums.phoenixrising.me/index.php?threads/distinguishing-cfs-new-zealand-research.51357/

    But as I mentioned above, I suspect that patients didn't achieve true VO2Max in this study either.
     
  15. Valentijn

    Valentijn Senior Member

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    I'm a little suspicious of that too. But it wouldn't be a VO2max without sufficient RER, and they are calling it a VO2max.
     
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  16. slysaint

    slysaint Senior Member

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    according to wikipedia:
    "many protocols for estimating VO2 max have been developed for those for whom a traditional VO2 max test would be too risky. These generally are similar to a VO2 max test, but do not reach the maximum of the respiratory and cardiovascular systems and are called sub-maximal tests."
    could this be what they're using?
     
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  17. Valentijn

    Valentijn Senior Member

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    No, because if it was submaximal, it wouldn't be maximal :p They say it's maximal.
     
  18. Snow Leopard

    Snow Leopard Hibernating

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    Maximal exertion occurs at maximum heart rate, well past the anaerobic threshold. A mean heart rate of 153 is far from the mean heart rate of ~37 year old women.
     
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  19. Dolphin

    Dolphin Senior Member

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  20. JaimeS

    JaimeS Senior Member

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    Very well-spotted re: why we don't always see the same results!
     

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