Muscle abnormalities worsen after post-exertional malaise in long COVID, 2023/4, Wüst, van Vugt, Appelman et al

I don't understand what Todd is saying.

VO2 max as an objective marker? A marker of what? Percentual decline in VO2 max looks to a substantial degree similar between ME/CFS patients and healthy controls when retesting on a 2-day exercise test.

Garner et al aren't claiming that patients are unable to expend maximal effort, but rather that their condition is due to them wanting to avoid this. What objective marker is he talking about?

 

Saw these on X. Not sure which Wüst study it was.
—-
Missconception that pacing means bed rest. In the study by Wüst et al the PASC cohort had around 5000 steps per day, average person walks 4900. Only difference healthy people can walk eg 10.000 steps without feeling „sick“ next day, in PEM PASC it’s not the case

—-.
Source for average person figure:

Large-scale physical activity data reveal worldwide activity inequality
https://www.nature.com/articles/nature23018

 

About as precise a description of the psychosomatic ideology as it gets.

 

I wish they'd all just stop having pissing contests on Xitter.

All we really know is that people who get PEM say they feel more ill, and have less capacity for activity, a day or two after exercise. And the ill feeling and reduced capacity can persist for a long time.

There's no proof they're not all lying through their teeth, but when reports are as consistent as that, they're usually given credence.

People firing competing bits of "truth" at one another in public gets us absolutely no further than listening to what people say.

 

There it goes again, the fear of PEM as the cause of the fatigue without ever addressing PEM itself. It's as if they are saying PEM is not real.

So, they acknowledge PEM is worsening of variety of symptoms, not just worsening of fatigue. I wonder when they will get around to explaining the worsening of other symptoms like light sensitivity or brain fog with their muscle anomaly model. It seems unlikely that multiple mechanisms are responsible for different PEM symptoms.

 

I have never been able to work out exactly what changes in VO2 max are supposed to be telling us. That is partly because I have never quite got clear in my mind what it is measuring but I think it is also due to something else. That is that in 10-20 years of people talking about this finding nobody seems to have come up with a theory of how it could be coming about. What are we supposed to think the mechanism might be?

It might be easy enough to suggest that following exertion there was some temporary structural shift in muscle, like macrophage activation or fluid ingress, or fibre apoptosis. And that is rather what Wust seems to be suggesting. But the problem with that is that we have evidence for any long term process of this sort. We do not see muscle atrophy and scarring of the sort seen in dermatomyositis.

The real problem I see for implicating the Workwell findings in a theory of PEM and 'damage' in ME/CFS is that there is no obvious way to link them to long term events. Muscle has huge regenerative powers - it is used to regenerating every day from usage. We would need a theory of why that changed. I am hearing nothing.

 

Karl Morten's group's discussion paper on the Wüst paper went into brain aspects.

 

I probably only understood 5 % of that. Are they saying that the root cause of PEM might be found in the brain or in the liver? Or possibly that the brain influences the liver, which in turn influences the mitochondria?

 

One of the findings in mecfs was slightly elevated liver enzyme’s and it appears also in Covid

https://pmc.ncbi.nlm.nih.gov/articles/PMC8713698/
Liver Injury and Elevated Levels of Interleukins, Interleukin-2 Receptor, and Interleukin-6 Predict the Severity in Patients With COVID-19

 

isn't he referring to the gas exchange ratio and other measurements at VO2 Max?

 

Trial by Error by David Tuller GET Ideologues Try to Rebut Muscle Abnormality Study - and Fail

quote:

It is a pleasure to read a pointed and effective smack-down of an ill-informed argument, especially when the argument is pushing the graded exercise therapy/cognitive behavior therapy (GET/CBT) paradigm for ME/CFS, Long Covid and related illnesses. That’s how I felt about the excellent rebuttal this week to a letter from some of the usual GET/CBT ideologues criticizing a study published last year in Nature Communications. That study reported a link between post-exertional malaise (PEM) and muscle abnormalities in people with Long Covid.

 

Not very important, but there’s a row of 8’s at the bottom of that post @dave30th It’s also at the bottom of the feb 14th post. It seems like it might stem from your disclaimer?

 

it was just a way of separating the disclaimer from the post. I could have used xxxxx or **** like I do within a post. maybe I should figure out some other symbol? I decided I should probably have the disclaimer on each post.

 

Probably a good idea! Better safe than sorry.

Not that you asked for it, but in my opinion, xxxxx could be interpreted as placeholder data - something is missing. 88888 could be interpreted as something gone wrong or something you forgot to delete. Unless you want to go really fancy, *****, ———, or ……. are probably the most pragmatic and universally recognized options. If you’re already using *****, I’d just stick with that.

 

Merged - response from the authors to a comment by Saris et al

We thank Saris et al. for their interest in our recent paper, which focused on the skeletal muscle components of post-exertional malaise (PEM) in Long COVID patients. We did not address the efficacy of exercise as a treatment, but our findings do not support that deconditioning or bed rest explains the skeletal muscle abnormalities in Long COVID. PEM is a distinct symptom that is poorly understood and not analogous to other conditions. We caution against generalizing our results to all Long COVID patients or drawing causal conclusions beyond the study’s design, and we advocate adherence to established guidelines that recommend avoiding activities triggering PEM.
LINK

 

I don’t understand how it’s possible to get so many basic things wrong when you’re talking about the subject of your specialized education and years of professional experience.

 

One of the things I’ve learnt with ME, is being an “expert” can sometimes make you worse off to explain it. When you are an expert and have been for a long time you often end up with vested interests in particular theories or angles.

In the case of ME it has led to some bubbles completely detached from reality, or in a completely alternate reality.