Urine Metabolomics Exposes Anomalous Recovery after Maximal Exertion in Female ME/CFS Patients 2023, Glass, Hanson et al

[Robert 1973]

My bold:

The lack of ability to adapt to an exercise stressor and recovery is such a major symptom so being able to objectively demonstrate an inability to achieve a basic bodily response to activity and exercise could be an important find if it can be replicated.

I just hope that somebody at least tries to replicate it. Not infrequently these pilot studies seem to turn up interesting results that nobody even tries to replicate, for whatever reasons.

I’ve not read the paper and I’m completely out of my depth so I apologise if this question doesn’t make sense but, if the results prove to be reliable, is it possible that the problem is with the excretion of the metabolites, rather than their production?

Another thing I’m wondering is whether there might be any value in doing a similar type of metabolomic analysis following alcohol consumption? Although it’s not a requirement for diagnosis, my understanding is that alcohol intolerance is a very common symptom in ME/CFS and that this is very unusually in other chronic illnesses. It has always felt to me like it must be a clue, and yet it doesn’t seem to be something that many researchers have taken much interest in investigating.

When I first became unwell in 1992, one of the ways I described my symptoms (as a 19 year old who knew nothing about ME/CFS and had never heard of PEM) was that it felt like I couldn’t get rid of the waste products that were being generated through aerobic activity. And it was the same feeling on the rare occasions that I felt well enough to try drinking alcohol.

 

[Hutan]

I'm half way through reading the paper. I've got to say, this is really well written. It's clear, and possible concerns (like issues with changes of concentration of the urine) are anticipated and answered. Just reading the Introduction, I feel as if the study was in safe hands. If anyone ever wants a clear summary of the 2 day CPET findings, there is one there.

One issue is the difference in BMI. The mean for ME/CFS was 24, the mean for controls was 33. Data was adjusted for age and BMI, so the authors claim that the differences detected are not due to differences in BMI, but I always feel a little uneasy when data is adjusted for things like that.

The differences are staggering though:



A is at baseline - the difference in the 1500-odd metabolites that were found to be present in either 80% of one of the groups, or 80% of both groups combined at baseline. Basically, no differences between the women with ME/SFS and the healthy controls.

B is the difference between the two groups after exercise. The horizontal dotted line shows significance - differences in metabolites above the line are significant. Bigger samples would no doubt increase the number of metabolites that are significantly different.




C and D show another way of looking at the data. These compare the before and after exercise data within each group. So, in C, there were big changes before and after exercise for the controls; lots of the changes were significant. In D, there was basically no change in the levels of metabolites in the urine the women with ME/CFS. It's such a big difference, it has me wondering if there is any mistake that might account for the lack of change in the ME/CFS samples (or the many changes in the controls). If it really is true difference, it does seem remarkable.

I wonder what is known about normal changes in metabolites in urine with exercise, and if the changes in the healthy controls found here match those.

 

[Hutan]

I’ve not read the paper and I’m completely out of my depth so I apologise if this question doesn’t make sense but, if the results prove to be reliable, is it possible that the problem is with the excretion of the metabolites, rather than their production?

I've had the same thought. If there is a lack of energy with processes working slowly, perhaps the kidney and the rest of the body just hasn't had time to get the metabolites out to the urine in the people with ME/CFS?

Another tweak on a replication would be to track changes in urine over a few days after exercise, not just one.

 

[bobbler]

Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with unknown etiology or effective treatments. Post-exertional malaise (PEM) is a key symptom that distinguishes ME/CFS patients. Investigating changes in the urine metabolome between ME/CFS patients and healthy subjects following exertion may help us understand PEM.

The aim of this pilot study was to comprehensively characterize the urine metabolomes of eight female healthy sedentary control subjects and ten female ME/CFS patients in response to a maximal cardiopulmonary exercise test (CPET). Each subject provided urine samples at baseline and 24 h post-exercise. A total of 1403 metabolites were detected via LC-MS/MS by Metabolon® including amino acids, carbohydrates, lipids, nucleotides, cofactors and vitamins, xenobiotics, and unknown compounds.

Using a linear mixed effects model, pathway enrichment analysis, topology analysis, and correlations between urine and plasma metabolite levels, significant differences were discovered between controls and ME/CFS patients in many lipid (steroids, acyl carnitines and acyl glycines) and amino acid subpathways (cysteine, methionine, SAM, and taurine; leucine, isoleucine, and valine; polyamine; tryptophan; and urea cycle, arginine and proline).

Our most unanticipated discovery is the lack of changes in the urine metabolome of ME/CFS patients during recovery while significant changes are induced in controls after CPET, potentially demonstrating the lack of adaptation to a severe stress in ME/CFS patients.

https://www.mdpi.com/1422-0067/24/4/3685

It looks very interesting.

I don't know enough about the measures they are looking at vs how long it would take for things to show in urine, but am intrigued by the method going for 'before' and '24hr after'.

Does that mean that they can tell (by these timings) whether these increases in healthy controls would have only occured after?

and that the PwME figure is actually 'no change' and not just that some of these things might have been depleted at some point yet only restores to where it was etc, even theoretically switching on early in the 'during' just to get through etc? Or that it is a matter of 'timing difference' etc. Although admittedly the graph post-exercise for ME/CFS does look dramatically flat and uneventful, I can't currently try and get my head around what is in those graphs re: calculations of 'differences' etc. but can see log function has been used (which would make 'much smaller change' look 'flat' ?)

There is always the potential that whilst CPET is a maximal stressor for HCs from what wasn't probably a situation where they were maximally stressed before, that situation/change isn't the case for anyone with ME/CFS whose task of just turning up on time to that first urine sample (if taken not at home several days prior) could mean they were say 90% there already at some point prior to what is deemed 'baseline'.

I'd be intrigued if there was potential to compare HC 'post-exercise' with ME/CFS 'baseline' perhaps for that reason even though it would be imperfect of course (timing of when it 'hits' and what people have been doing before etc). My point is that this could be showing - if I'm reading right that the graphs are plotting change rather than absolutes - potentially more the 'envelope situation', or being beyond that more constantly (like a vehicle with a tiny engine having to drive at its max on the side roads before it even gets to the motorway) over the entire period vs the 'hit' applied to HCs of turn up for a CPET.

It is still interesting though and I can see the likelihood that the answers to these questions makes 'averaging' PwME graphs as a result less useful - ie 24hrs sort of makes sense, then individual differences potentially across those with ME could happen more? And the issue with urine being that timings and aspects which are individual start layering on each other too.

I guess with urine using '24hr urine' ie all urine output over the 24hrs collected into one, (or different time chunks) could provide some 'pros' in answering some questions too (checking nothing happened in that xhrs period) vice versa.

I don't know whether there is equivalent research studying these measures in 'healthy controls' (noting they are sedentary too, and their BMI median being 33.3 vs 24 for ME/CFS group) or any other health conditions.

 

[bobbler]

My bold: I just hope that somebody at least tries to replicate it. Not infrequently these pilot studies seem to turn up interesting results that nobody even tries to replicate, for whatever reasons.

I’ve not read the paper and I’m completely out of my depth so I apologise if this question doesn’t make sense but, if the results prove to be reliable, is it possible that the problem is with the excretion of the metabolites, rather than their production?

Another thing I’m wondering is whether there might be any value in doing a similar type of metabolomic analysis following alcohol consumption? Although it’s not a requirement for diagnosis, my understanding is that alcohol intolerance is a very common symptom in ME/CFS and that this is very unusually in other chronic illnesses. It has always felt to me like it must be a clue, and yet it doesn’t seem to be something that many researchers have taken much interest in investigating.

When I first became unwell in 1992, one of the ways I described my symptoms (as a 19 year old who knew nothing about ME/CFS and had never heard of PEM) was that it felt like I couldn’t get rid of the waste products that were being generated through aerobic activity. And it was the same feeling on the rare occasions that I felt well enough to try drinking alcohol.

I find the alcohol one fascinating too - you almost feel there might be some paper-based clues from it too. The thing is .. I initially jumped to the 'being a lightweight' type issue too (tho that always seemed to point to something for me, as it has happened with v small amounts of certain 'normal' alcohol types and the drunkness was v fast so wondered if that was a metabolism/pathway-related remark based on that) - then realised that runs into all sorts of arguments and issues based on other things that relate to tolerance like ...building one up by drinking, would you be able to get controls who were similar on all of these who would be prepared to drink for the test too?

 

[Sean]

Can't recall seeing any differences this stark before.

View attachment 19030

 

[Hutan]

Can't recall seeing any differences this stark before.

There was the recent fibromyalgia versus ME/CFS and healthy control difference in a study, but in that case the fibromyalgia samples came from a different source, and it seemed likely that some differences arising from storage probably accounted for the difference. There doesn't seem to be any similar reason here, although it would be good to have the researchers confirm the handling of samples was identical.

I'd be intrigued if there was potential to compare HC 'post-exercise' with ME/CFS 'baseline' perhaps for that reason even though it would be imperfect of course (timing of when it 'hits' and what people have been doing before etc). My point is that this could be showing - if I'm reading right that the graphs are plotting change rather than absolutes - potentially more the 'envelope situation', or being beyond that more constantly (like a vehicle with a tiny engine having to drive at its max on the side roads before it even gets to the motorway) over the entire period vs the 'hit' applied to HCs of turn up for a CPET.

(If I'm understanding things correctly, I'm starting to lose my grip on thoughts
I don't think the data supports that idea of people with Me/CFS already being in a 'post-exercise' situation in terms of urine metabolites.

Chart A above compares the ME/CFS and HC samples at baseline (so absolute values, not any change). So, it's not comparing any change, just between group differences. None of the identified differences in the metabolites were significant. So the ME/CFS samples at baseline looked like the HC samples at baseline. The x axis label might be a bit misleading, it refers to change, but actually it's the difference between the mean value of the ME/CFS samples and the HC samples. But it's the y axis that really matters, because that tells us which of the metabolite differences are significant - differences will be significant when there is both a difference between the groups and the variability of the values within the group is relatively low.

Chart C shows that the control samples changed from their baseline; Chart D shows that the ME/CFS samples didn't change. So, with a start point of the samples from both groups looking the same, I don't think we have grounds to say that the ME/CFS samples before exercise were looking like the HC samples after exercise. e.g. both the ME/CFS and HC samples could have a mean of 2, before exercise, and the HC sample is 5 after exercise but the ME/CFS after exercise is still 2. A larger sample might possibly find some metabolites with a statistically significant pattern along the lines of what you are suggesting, with some ME/CFS baseline values looking like HC values after exercise.

 

[voner]

I look forward to hearing Maureen Hanson's comments about this study and hear which of these findings she thinks are significant. As @Hutan stated, the paper is clearly written.

 

[Hutan]

Acyl glycine fatty acid metabolites are the only compounds that were found in urine at significantly different concentrations in ME/CFS vs. controls at a single time point (24 h post-exercise)

I assume the lower levels of these metabolites after exercise in the ME/CFS samples compared to the heathy controls is a key finding. See chart B above- the red dots. I just hope the difference isn't due to the higher BMI of the healthy controls.

I've got to the end and I see the authors acknowledge the lack of BMI matching as a limitation. They note:

Our larger cohort of ME/CFS patients and healthy sedentary controls is BMI-matched, and therefore if this pilot study is expanded, this will not be an issue in the future.

which is encouraging.

They also note the point we have made about the need to take samples for a longer period to see if the excretion of metabolites is just delayed, rather than not happening at all.

Additionally, because we captured the urine metabolome only at two time points, baseline and 24 h post-exer- cise, we cannot say whether or not the ME/CFS patients have altered excretion levels of some of these metabolites at either an earlier or later time point than the controls. It is possible that these increases in excretion products are happening in patients but with a larger delay, similar to how the ME/CFS patients show a delayed overall recovery to ex- ercise. However, it is also possible that this lack of altered metabolic excretion is part of an overall lack of a healthy metabolic response to exercise.

So, like I said, safe hands. Hopefully they will be well-funded to keep working.

 

[livinglighter]

I'd like to know if similar findings also happen in similarly related conditions.

 

[Hoopoe]

What kind of problem could be causing such drastic changes in a wide range of metabolites?

Is there a body wide "rest, repair and recover" signal that is broken in ME/CFS?

It seems to make sense that people so affected would have to rest a lot because they are gaining much less recovery from it.

I know about growth hormone and its role in recovering from exertion. What else is there?

 

[John Mac]

I just hope that somebody at least tries to replicate it. Not infrequently these pilot studies seem to turn up interesting results that nobody even tries to replicate, for whatever reasons.

I get the impression that this is a major problem in ME/CFS research. The number of un-validated studies must be running into the hundreds if not thousands by now. Many researchers are not interested in other researchers work as it's not their speciality or they don't have the same equipment which is fair enough but I can't help getting the impression that the main reason is that it's not "their" baby. Why bother validating somebody else's work, what's in it for "me", proving somebody else right?

We need an overall authority in charge of ME/CFS research with a wider view of what is needed deciding which studies need replicating, which new avenues of research need looking into and offering funding to researchers to carry out these studies. Now we have the opposite, researchers carrying out the research that they want to not what is needed.

 

[Robert 1973]

I get the impression that this is a major problem in ME/CFS research. The number of un-validated studies must be running into the hundreds if not thousands by now. Many researchers are not interested in other researchers work as it's not their speciality or they don't have the same equipment which is fair enough but I can't help getting the impression that the main reason is that it's not "their" baby. Why bother validating somebody else's work, what's in it for "me", proving somebody else right?

We need an overall authority in charge of ME/CFS research with a wider view of what is needed deciding which studies need replicating, which new avenues of research need looking into and offering funding to researchers to carry out these studies. Now we have the opposite, researchers carrying out the research that they want to not what is needed.

@Jonathan Edwards Is this something that’s been discussed in the DHSC research group that Javid initiated?

Is there a thread on that group anywhere or are discussions confidential at this stage? Sorry, I’ve been out of the loop for a while and have lost track of developments.

 

[Robert 1973]

I've had the same thought. If there is a lack of energy with processes working slowly, perhaps the kidney and the rest of the body just hasn't had time to get the metabolites out to the urine in the people with ME/CFS?

Another tweak on a replication would be to track changes in urine over a few days after exercise, not just one.

Good to see that this is considered in the paper as you quote above.

Is it possible that excretion of metabolites could be affected by endothelial dysfunction?

 

[mariovitali]

@John Mac Amen

I get the impression that this is a major problem in ME/CFS research. The number of un-validated studies must be running into the hundreds if not thousands by now. Many researchers are not interested in other researchers work as it's not their speciality or they don't have the same equipment which is fair enough but I can't help getting the impression that the main reason is that it's not "their" baby. Why bother validating somebody else's work, what's in it for "me", proving somebody else right?

We need an overall authority in charge of ME/CFS research with a wider view of what is needed deciding which studies need replicating, which new avenues of research need looking into and offering funding to researchers to carry out these studies. Now we have the opposite, researchers carrying out the research that they want to not what is needed.

 

[Andy]

Mauren Hanson on Twitter, "The lead author of our recent urine metabolomics paper, Dr. Katie Glass, has provided a brief video abstract."

The volume seems to be very quiet on the video.

 

[voner]

in this 2023 paper, the authors state that this group of patients were in the same subject group on their previous metabolomics paper in March 2022. Here’s the quote from the current paper. That paper had similar BMI for controls and subjects.

Our group previously published plasma metabolomics data from these same subjects [25]. These subjects underwent the complete two-day CPET protocol and along with urine collection, blood was drawn from each subject at four time points: baseline (P1), 15–30 min after the CPET (P2), 24 h after the CPET (P3), and 15–30 min after the second CPET (P4) which was performed 24 h after the first CPET (Figure 1A in [25]).

this previous paper is discussed here:

https://www.s4me.info/threads/plasm...ud-germain-maureen-r-hanson-et-al-2022.25196/

and the title and abstract:

Plasma metabolomics reveals disrupted response and recovery following maximal exercise in myalgic encephalomyelitis/ chronic fatigue syndrome, Germain, et al, March 31, 2022.


Post-exertional malaise (PEM) is a hallmark symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We monitored the evolution of 1157 plasma metabolites in 60 ME/ CFS (45 female, 15 male) and 45 matched healthy control participants (30 female, 15 male) before and after 2 maximal cardiopulmonary exercise test (CPET) challenges separated by 24 hours, with the intent of provoking PEM in patients. Four time points allowed exploration of the metabolic response to maximal energy-producing capacity and the recovery pattern of participants with ME/ CFS compared with the healthy control group. Baseline comparison identified several significantly different metabolites, along with an enriched percentage of yet-to-be identified compounds. Additionally, temporal measures demonstrated an increased metabolic disparity between cohorts, including unknown metabolites. The effects of exertion in the ME/CFS cohort predominantly highlighted lipid-related as well as energy-related pathways and chemical structure clusters, which were disparately affected by the first and second exercise sessions. The 24-hour recovery period was distinct in the ME/CFS cohort, with over a quarter of the identified pathways statistically different from the controls. The pathways that are uniquely different 24 hours after an exercise challenge provide clues to metabolic disruptions that lead to PEM. Numerous altered pathways were observed to depend on glutamate metabolism, a crucial component of the homeostasis of many organs in the body, including the brain.


here is a quote from the March 2022 paper about the symptom levels of the patients:

Nevertheless, the selected ME/CFS population was capable of traveling to the testing sites and performing 2 CPETs and would therefore be considered to have less severe symptoms compared with patients who are bedbound. However, the scores on the Bell scale and 36-Item Short-Form Health Survey (SF-36) indicate that very few patients could be considered to have mild disease.

 

[bobbler]

I get the impression that this is a major problem in ME/CFS research. The number of un-validated studies must be running into the hundreds if not thousands by now. Many researchers are not interested in other researchers work as it's not their speciality or they don't have the same equipment which is fair enough but I can't help getting the impression that the main reason is that it's not "their" baby. Why bother validating somebody else's work, what's in it for "me", proving somebody else right?

We need an overall authority in charge of ME/CFS research with a wider view of what is needed deciding which studies need replicating, which new avenues of research need looking into and offering funding to researchers to carry out these studies. Now we have the opposite, researchers carrying out the research that they want to not what is needed.

I remember the very valid point made by @Jonathan Edwards that a big 'link in the chain' that is missing for ME/CFS is proper medical clinics and suspect this is a major hurdle.

Recruitment of those who are definitively with ME/CFS but the right level of illness for a particular study and able to participate due to location must be made all the harder vs this being one 'source' for most/many (?) other conditions - and indeed all the trust issues (including 'will it affect my health' given how precarious the situation for most with ME/CFS is, with little responsibility currently taken by anyone for 'remedying if they put them through treatment that harmed them' etc).

From a research point of view it is where people get their feet wet and become interested in other theories - we are missing the 'hands on' vs desk-based only experience being prevalent to create some oomph etc?

 

[Jonathan Edwards]

We need an overall authority in charge of ME/CFS research with a wider view of what is needed deciding which studies need replicating, which new avenues of research need looking into and offering funding to researchers to carry out these studies. Now we have the opposite, researchers carrying out the research that they want to not what is needed.

@Jonathan Edwards Is this something that’s been discussed in the DHSC research group that Javid initiated?

Actually we do have this in the UK. It is the MRC. To be fair they did just this. Eleanor Riley was charged with asking experts what research was considered worth pursuing and what new avenues were worth looking in to. They identified a genome-wide study and offered funding.

The chief reason why researchers do not replicate ME studies is that they don't think there is a strong likelihood of anything coming out of it with a significant impact. There are some preliminary metabolic findings that are probably worth checking but in general in research the team putting out such preliminary data is expected to take it far enough to look reasonably convincing before others invest time in replicating.

The one thing that has been identified by the DHSC group where there is a general agreement that further studies would be welcome is in re-purposing of drugs. So far the only clear candidate is naltrexone but it could be used as a test model for methodology that could be rolled out for other drugs.

 

[butter.]

Hanson is the MVP in ME/CFS research, imo. Her work is very well structured and concise, very consistently so, in everything she does. It is actually fun to read most of her papers. We can be really glad to have her in our corner.