arrow18 Comments
  1. John
    Sep 17 - 2:19 pm

    Sounds like getting the 2-day exercise test studies replicated by an independent group is becoming a top priority. I wonder if the CAA would consider possibly changing or alternating from their usual strategy of receiving applications and go for a direct route of commissioning a study in this case?

    • Cort Johnson
      Sep 17 - 3:43 pm

      I don’t know if they’d do that but they certainly could. The CAA did that before, I believe, when they commissioned an XMRV study.

  2. POTSNJ
    Sep 17 - 2:45 pm

    I have a CFS diagnosis and had this testing done in Ithaca last month. I didn’t show the 2nd day response on VO2Max or AT. My numbers were very low, but consistent both days. I did have a different result day 2 under the hemodynamic category, specifically my blood pressure didn’t respond appropriately during the latter half of the test which I was told could have been the result of PEM induced autonomic instability. However, I have POTS (probably from autonomic neuropathy) which doesn’t always act exactly the same everyday and could also explain this result. Have enough people with CFS had this testing done to prove that this is a definitive biomarker? I know of another person with CFS who had the testing done and also performed poorly, but consistently both days. I’m concerned that we’re prematurely pushing this 2nd day testing issue without more proof that it’s a consistent result in most CFS patients. Have a lot people in the real world actually gone and had the test done and showed the 2nd day response? I’m worried that people like me who may actually have CFS, but don’t show the 2nd day change will lose their diagnosis. Of course it’s also possible I’m just misdiagnosed. I’m glad I went for the testing though because even if I didn’t get the proof of CFS I was looking for, I did get other information that I need to pursue. My VO2 Max is very very low and this information may help explain why I feel so terrible – now I need to find out *why* it’s so low.

    • Cort Johnson
      Sep 17 - 3:16 pm

      I think your results show why this testing is valuable; even though you didn’t fit a certain profile it did show that you have significant abnormalities in VO2max and blood pressure regulation.

      I imagine that the more people who do this test the more abnormalities will show up. Dr. Newton’s studies suggest that autonomic nervous system problems underlie all sorts of fatigue issues in other diseases. I think you’re probably just a subset of a larger subset of patients with autonomic and energy production issues.

      The goal, in my opinion, is not necessarily to get a diagnostic marker but to open up this area for more research which will illuminate what’s going on with you as well.

      With regards to low energy production at VO2 max or ventilatory threshold; we have three studies and the experience of two experts in the field that these are common problems in ME/CFS but we do need more study, for sure.

      Good luck on finding out what’s causing your low VO2 max result.

      • POTSNJ
        Sep 17 - 5:14 pm

        I agree Cort. I think the testing is worthwhile for anyone struggling with extreme fatigue, energy problems, malaise, exercise intolerance. You really get a lot of information out of the results. And Dr. Keller was very kind, took a lot of time talking to me and explaining things, seems to really care. I also didn’t have any bad health effects that people seem worried about as a result of the test. It was an overall positive experience. It just seems all the emphasis is on that 2nd day change and if that doesn’t happen, then what, you don’t have CFS? I guess time and more studies on us will tell.

        • Cort Johnson
          Sep 17 - 6:06 pm

          I think this illness is so fluid with so many subtypes that there never will a true ME/CFS. Instead, I think researchers will uncover fundamental problems that give rise a variety of similar illnesses; similar to what Marco suggests with this neuroinflammatory hypothesis.

          And I think you and I (I don’t what my test retest scores are) will be right in there. :)

          • John
            Sep 17 - 9:01 pm

            Somehow it seems like I remember that either in the Pacific Fatigue Lab’s application for NIH funding or in some of their previous studies, only about half of the patients showed the 2nd day decrease. If I am remembering this (at least somewhat) correctly, how did it go from roughly 50% of patients showing the abnormality to the test being almost diagnostic for the disease, ie in the 90% range? Am I mistaken about the 50% figure?

            • Cort Johnson
              Sep 18 - 7:28 am

              It’s possible. I don’t know if any other study attempted to diagnose patients based on exercise results.

              I looked at the Vermoulen study. A small one but the results just pop out at you; lower work rates (in fact the work rate in healthy controls increased in the second test), oxygen uptake, oxygen pulse – all highly significant.

              The work rate was 4.40 ± 9.66 W less in the patient group and 7.67 ± 19.50 W higher in the control group (P = 0.002, 95% CI: -23.6; -0.55). Such differences were also found for the oxygen pulse (-0.67 ± 0.93 mL/beat versus 0.25 ± 1.09 mL/beat; P = 0.014, 95% CI: -1.68; -0.16) and oxygen uptake (-0.87 ± 1.07 mL/kg versus 1.07 ± 2.63 mL/kg; P = 0.001, 95% CI: -3.61; -0.26).

              Similar changes were found at maximal work rate: The work rate was 6.33 ± 11.5 W less in the patient group and 11.1 ± 18.3 W higher in the control group (P < 0.001, 95% CI: -28.8; -5.99). And the changes in the oxygen uptake were likewise (-1.33 ± 1.68 mL/kg versus 0.73 ± 1.39 mL/kg; P < 0.001, 95% CI: -3.22; -0.92).

              The improvement in the performance of the controls is likely due to the effect of training. In the group of patients the performance is the result of a similar training effect which is counteracted by the effect of the postexertional malaise.

  3. Nat
    Sep 17 - 8:05 pm

    I haven’t had the two day test, but did have a one day test and also scored very low. And in my search for information about my illness, in reading Ritchie Shoemaker’s Surviving Mold he states that “most mold illness patients will have a VO2max so low they qualify for a Class III or IV cardiac disability.” I qualify as Class III. I find it interesting that I felt biotoxins were a component of my CFS before I learned this, when most of what I have read says CFS/ME patients have a relatively normal one day exercise test. I do find that hard to believe however, as debilitating as this illness is for most. And it makes me wonder if those participating in the one day exercise tests aren’t mostly highly functioning patients.

  4. Gijs
    Sep 18 - 3:21 am

    If i understand correctly from specialists it it also possible that very bad results shows up with a singel CPET test. This group do not need a second test to validate there disability. But the problem with a single test is that they can say: ‘o, you are deconditioned’.

    • POTSNJ
      Sep 18 - 7:37 am

      Yes Gijs, this was another concern of mine – the whole deconditioning theory. I even thought to myself ok, if I score low, but consistently, maybe I’m just deconditioned and need to exercise. The thing is the average VO2 max for a sedentary female my age is around 26-30. I scored a 17. I know my own activity level and I at least match a sedentary lifestyle, probably surpass it a bit because I have two young children and have to push myself a little. When they assess surgery candidates with CPET they want the AT score to be above 11 because if not, your risk for complications and death is much higher. I’m at a 9.6. Why? I’m not 90, not bedridden – it doesn’t make sense. And for the people stuck in bed maybe this is what put them to bed to begin with! No, we’re sick, something is definitely wrong.

      • Gijs
        Sep 18 - 9:29 am

        I understand you have POTS? If you have POTS this CPET and Vo2max is not reliable because they measure you maximum hartrate at one point. Your hartrate is already very high when you sit on the bicycle, correct?

        • POTSNJ
          Sep 18 - 12:43 pm

          Gijs – My heart rate is typically highest when I’m standing and can sometimes be a little high when sitting. Good thing the test is on a bike, not a treadmill. During the beginning of the test, at rest just sitting on the bike, my heart rate was 82 the first day and 90 the second day. Ha, just noticed my heart rate was 5-10 points higher the 2nd day throughout most of the test. That’s interesting. Anyway, according to the report my heart rate responded normally throughout the test, so the POTS didn’t seem to be a factor on this measure.

  5. Gijs
    Sep 18 - 9:57 am

    Hi Cort, Is the CDC looking for NK-Cel Dysfunction in there study?

    • Cort Johnson
      Sep 18 - 10:30 am

      Yes, they are. I’m not sure if they’re incorporating it with the exercise study but it does appear to be in the study.

  6. Waiting
    Sep 18 - 10:36 am

    I think it would be interesting to know whether Dr. Keller knew someone with ME, perhaps a relative or friend? It just seems that so many of the medical professionals who study and treat ME patients entered the field as a result of a personal connection like that … or as a result of a patient of theirs presenting with ME. It seems from your article that her introduction was through a patient. Good for her to agree to do the protocol and then to follow through with it the way she has. We need more medical professionals like her.

  7. Andrew
    Sep 18 - 11:25 am

    What were the other conditions to show a lack of reproducibility in VO2Max or other metabolic parameters I wonder?

    • Cort Johnson
      Sep 18 - 11:30 am

      Yes, people with a variety of serious disorders from heart disease to kidney disease to COPD have been able to reproduce their results on the second day – as have healthy controls.

      I have a list of about 12 studies, most fairly small – showing this. None showed a drop the second day.

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