Post-Exertional Malaise Is Associated with Hypermetabolism, Hypoacetylation and Purine Metabolism Deregulation in ME/CFS Cases, 2019, McGregor et al

[obeat]

@Wonko Could you pm me also? Thanks

 

[Andy]

I wrote a post, decided it was just too OT for this thread, even for me, so I've sent you a PM, containing what I wrote.

Could you perhaps post it elsewhere? Here would be a good place perhaps? https://www.s4me.info/threads/using-heart-rate-monitoring-to-help-with-pacing.196/

 

[Hutan]

As far as I can see, the abnormalities found here could be unrelated to exertion. Or did I miss something?

I agree. I'd have expected, in metabolites that might tell us something about PEM, that either the level in the controls would be high, the level in the people with ME/CFS who reported a low level of PEM symptoms in the last seven days would be lower and the level in the people with ME/CFS who reported a high level of PEM symptoms would be lower still. Or vice versa.

Instead, it's the people with ME/CFS with low recent PEM who look most different to the controls. Of the 12 serum and urine metabolites reported in Table 2, only one, phenylalanine, follows the expected pattern. I've charted the figures here:



With results like that, I'm wondering how useful the two categories of people with ME/CFS are; whether the criteria for the categories really do distinguish between people still showing the effects of PEM; or whether these metabolites have anything to do with PEM.

Later in the paper there's a suggestion of a physical process associated with PEM that might be confounding metabolite levels:

These data show a significant renal concentrating issue is occurring in the ME/CFS group during a PEM event and this was principally related to urea and acetate.

Thus the 7-day severity of PEM was associated with an increased urinary excretion of metabolites within the ME/CFS group and this was associated with a reduction in multiple serum metabolites including leucine.

The figures given for urine acetate and urine urea were:

Urine acetate: Control 92; No PEM 37; PEM 63
Urine urea: Control 7969; No PEM 4868; PEM 5821

I'm not really sure if they have something here or not. I need to read the paper again. There were quite a lot of metabolites tested and then they did a lot of different things with the figures; absolute levels, percentage of metabolites, ratios, correlation with the 7 day PEM score (in both whole group and just the ME/CFS group) and with the 12 month frequency of PEM score.

To be fair to the authors, they aren't claiming to be sure if they have something here or not either. Just that it's worth looking at some of these things some more.

 

[Milo]

i wonder whether there would be a difference between PEM self-report and provoked PEM-with timely blood collection. And of course it would involve much effort in going through ethic reviews and performing the exercise tests. That would be a much different study design, but it would control the self-report aspect which is always problematic in my view.

It seems to me that it can be hard to tell sometime whether you are in PEM or not if you push yourself every day and end up having symptoms every day.

My 2 cents.

 

[Midnattsol]

i wonder whether there would be a difference between PEM self-report and provoked PEM-with timely blood collection. And of course it would involve much effort in going through ethic reviews and performing the exercise tests. That would be a much different study design, but it would control the self-report aspect which is always problematic in my view.

It seems to me that it can be hard to tell sometime whether you are in PEM or not if you push yourself every day and end up having symptoms every day.

My 2 cents.

But since people experience PEM at different times after exertion, you would probably have people at different stages of PEM if you had blood collections at specific time points.

 

[Saz94]

Would 'hypermetabolism' explain why I am really hungry during PEM?

 

[Hoopoe]

Would 'hypermetabolism' explain why I am really hungry during PEM?

I have the same reaction. Eating seems to compensate a little bit.

My mental model of this was hypometabolism in the sense of lacking energy and trying to compensate for it, but it could also be thought of as hypermetabolism.

Anyway the idea that there are changes in metabolism seem to be consistent with what is happening in reality.

 

[Midnattsol]

Would 'hypermetabolism' explain why I am really hungry during PEM?

I have the same reaction. Eating seems to compensate a little bit.

I don't always get very hungry when I have PEM, but often. To me it makes sense, if the body has an increased need for certain nutrients (and energy) then starting up some hunger-signalling pathways seems like a good idea.

 

[Denise]

And yet anecdotally some (I have no idea how many) patients barely have the energy to eat during PEM.

 

[Mij]

I'm normally a very good eater, but in PEM I lose my appetite.

Doesn't our digestive system require a lot of ATP to process and digest food? Something I have less of in PEM.

 

[Hoopoe]

Maybe in some patients the body reacts by trying to compensate with increased nutrient intake, in others maybe it reacts by reducing energy expenditure to a minimum.

 

[Mithriel]

Sometimes I think our results are normal because they are so wrong! For instance I tend not to fall over during a romberg test (closing your eyes) because I am so bad I fall over when I blink so I have trained myself to feel the ground through my feet.

Relevant to these results this way. Healthy controls have a certain level of substance A in their blood because the body produces it and then gets rid of it in the normal way. Patients who are in low PEM produce substance A but do not have the resources to mop it up so their levels are high. Patients in bad PEM do not have the resources to produce substance A so their figures match the healthy controls yet they are the most sick.

 

[wigglethemouse]

@wigglethemouse what do you think? Recall the connection of Glutamate with Adenosine-Triphosphate (ATP) shown on Network Analysis i posted above

@mariovitali I watched the recent Hardvard OMF talk by Mike VanElzakker. In the brain in PEM both Glutamate and Glutamine are reduced vs baseline scan (small sample size, unpublished data) as well as reduced blood flow in certain areas (blood flow on previous slide, sample 2 people, duplicating others work but in much greater detail with newer technology)

Talk :


Slide at 17m:19s

 

[mariovitali]

@wigglethemouse

Thank you, i am adding hypoperfusion to the software system to see what i am getting (currently 10K abstracts) and see what kind of connections occur with other known concepts of interest.

I looked for some papers and found the following figure. Many concepts there we've seen before :

Link : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5094314/figure/fig1-0271678X16666846/

Lower glutamine / glutamate levels are a result of hypoperfusion from what i understand. I will have to read more about this.

 

[Ravn]

it's the people with ME/CFS with low recent PEM who look most different to the controls

Sometimes I think our results are normal because they are so wrong!

I've also been trying to get my head around this seeming contradiction. Wondering if there could be a kind of compensation mechanism at play?

An example of such a mechanism would be my experience of OI, which I've seen other people describe, too.

• When my ME was mild I had problems with fainting due to my BP dropping on standing. So my BP was very different from a healthy person's.
• Once I got more severe I began to have compensatory tachycardia, at least that's how I interpret it, and that compensatory tachycardia kept my BP up. So now my BP looks perfectly normal (even though my HR doesn't).

So if you only look at my BP I looked ill while mild but healthy while severe.

Not saying that something equivalent in PEM is a likely mechanism to explain the more normal results with PEM than without PEM in this paper, only that it's the only mechanism I could think of apart from the results simply being random coincidences. @Mithriel added another angle. Can anyone add more possible explanations?

 

[Subtropical Island]

I'm normally a very good eater, but in PEM I lose my appetite.

Doesn't our digestive system require a lot of ATP to process and digest food? Something I have less of in PEM.

I’d make a distinction between hunger and ability to eat and digest.
In the sense of:
The first is a motivation, a signal given by whatever it is the body does to make desires and compulsions etc.
The second is a response to the action that results.

E.g. I can be (feel) ravenous, driven to eat etc. But also really struggle to digest the food my body seemed to want. Or perhaps for some, even struggle with the eating part (bite, chew, swallow).

ETA: have not read this thread yet, just a few comments so let me know if this is OT.

 

[mariovitali]

The following paper was retrieved with the Information Extraction system i've been using lately and i am inclined to contact Dr Jonas Berquist :




@wigglethemouse what do you think? Recall the connection of Glutamate with Adenosine-Triphosphate (ATP) shown on Network Analysis i posted above

Well, i can definitely say that this day has a lot of positive vibes. Both Dr Phair and Dr Bergquist replied back today saying that they will look at some associations that the Information Extraction tool has found with excitotoxicity, kynurenine, glutamate and the paper cited above mentioning hypoxanthine in Cerebrospinal Fluid (CSF). Dr Bergquist's response was very positive i would say regarding Hypoxanthine and CSF in the sense that such finding sounds very interesting .

I am finding connections in both hypoxanthine (Dr McGregor) and hypoperfusion (Dr VanElzakker). I will post as soon as i have the results in the Machine Learning thread so as to not be OT here.

 

[JemPD]

No comments on this study @Jonathan Edwards?
I'd be interested in your thoughts as well as other people's, particularly as it's rather beyond me & i don't want to waste my energy learning about 'Hypoacetylation and Purine Metabolism' if it looks like it could be a blind alley.

 

[hinterland]

I agree. I'd have expected, in metabolites that might tell us something about PEM, that either the level in the controls would be high, the level in the people with ME/CFS who reported a low level of PEM symptoms in the last seven days would be lower and the level in the people with ME/CFS who reported a high level of PEM symptoms would be lower still. Or vice versa.

Could it be both the controls and high PEM patients have been active; whereas low PEM patients have been resting? So the metabolites measured correlate with activity levels, not necessarily disability.

 

[hinterland]

Does anyone else keep needing to pee when on the verge of crashing? What could this mean?!