2 Day CPET discussion - is it evidence that GET is harmful, and is it a biomarker?

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David Tuller: Trial By Error: The Cochrane Controversy

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The downside of GET is that there is also abundant evidence of it doing immense measurable harm. That is something we need to focus on more. People with a broken aerobic metabolism do not benefit from aerobic conditioning.

 

I think that the evidence of harm from GET is still pretty weak, so reckon we're best off pointing to the lack of any good evidence for efficacy. The concern about harms made more important, even if the evidence there is still weak, when it's balanced up against poor evidence of benefit from research with serious flaws.

 

No, it isn't. The psych evidence for harm is weak, the exercise physiology evidence is quite robust. Its just that the psych papers totally ignore it.

 

But GET proponents can always argue that studies not specifically designed to test GET cannot be used to claim that GET causes harm.

 

Yet studies that show aerobic exercise always causes harm trump that.

 

Do we have studies showing that aerobic exercise always causes harm?

 

We have nearly 100% evidence of harm from aerobic exercise. What we do not have is proof of long term harm in formal studies. Its obvious, but not done in studies in part because its considered highly unethical. We don't have to prove many poisons are harmful by subjecting people to them over a long time to gather evidence.

 

Which do you think that strongest studies to show GET is harmful are? I've not kept up with recent ones, but in the past I thought that it was a bit of a reach to try to extrapolate from studies which indicate ME/CFS patients have abnormal responses to certain forms of exercise to claiming that they showed GET was harmful.

 

They show any exercise that crosses the anaerobic threshold is damaging, and that in us the anaerobic threshold is very very low, and we can cross it without even getting out of bed according to a few reports. If the GET research wants to show this is not the case they can use this technology and get hard data. They do not do so.

PS Just recently it was announced that one patient had a 44% decline in energy after some brief exercise to tolerance, within twenty four hours. I hope I am not misremembering. That is nearly a fifty percent decline in one day, and not for prolonged or difficult exercise. No other disease is known that does that.

 

@alex3619, like @Esther12 I am not aware of any studies that show actual harm, in the sense of long term deterioration being shown to be caused by exercise. A decrease in exercise capacity in response to exertion over a two day period does not indicate harm. Training with eccentric muscle usage (muscle contraction while lengthening) in normal people produces a deterioration in muscle function in the short term but in the long term is not harmful. An elite tennis player will be less good at winning the day after a long match but that does not mean that playing tennis does them harm.

 

What do you make of the two-day CPET studies? Apparently, even MS and COPD patients repeat their results (or get better) due to the effect of training. Do you think this is reliable or is capturing some other confounding issue?

 

MD Katarina Lien has been working on a PhD on ME, exercise and lactate levels. She's done research on ergospirometry and ME. I think the publication should be just around the corner. She's also been one of the researchers in RituxME.

She is going to give lectures on PEM on the upcoming ME conferences in Sweden next month.

 

I don't now. I am actually sceptical that 'training' can occur in 24hrs. Cardiac output is not going to improve in that time, for instance. I would like to understand the physiology better but I find the way these studies are written up very opaque.

 

I guess that exercise tests will provide a lot of knowledge. In theory of PEM,it seems like gold standard, except from patients at risk when pushing limits. That is a little (or much
) on the side, but obviously a little problematic.

A 2-day test is for practical reasons good, but what I find a little troubling knowing the dynamics of ME, is the short timespan, ref sometimes delayed PEM, PEM in several steps and things like that. So ideally these test should be followed up in longer timespan.

I can’t trust my short-term memory but isn’t Lipkin and his team going to do exercise tests and thorough follow-up. Seems like that study will cover the depths of PEM.

 

The trouble with studying harms of GET, are that:

- Those who believe GET causes no harm can carry out studies, but they are not careful about looking for harms, because they don’t think they exist. (And patients don’t trust them to properly record harms).

- Those who believe GET causes harm, cannot ethically conduct studies to discover and document that harm.

So we are left in the Catch 22 of “no evidence of harm”. At least no evidence beyond large patient surveys, and reports from some PACE participants that the harms they described were not documented.

So where do we go from here?

 

Yeah, Simon blogged on it here, https://mecfsresearchreview.me/2018...-collaborative-probes-the-impact-of-exertion/

 

there was a similar problem raised with the NICE guidelines committee in 2007 re searches
on GET:
""Just one example of this is GET; the question posed by the York team looked for papers on ‘GET and ME/CFS’, it did not however search for papers on ‘Exercise and ME/CFS’, and this meant that the many papers showing the potential harm of exercise on the bodies of people with ME/CFS, and that people with ME/CFS react adversely to exercise were not picked up, "

see also problems with PACE reporting of harms:
https://www.s4me.info/threads/pace-trial-graphs-and-gifs.4860/page-2#post-87743

 

I have not only not disputed there are no studies showing long term harm from GET, I have said so myself.

The problem is this is completely irrelevant.

There are no adequate studies showing its safety either. PACE does not do so.

If this were a drug, with zero proper safety studies, then would it be acceptable to defend it on the basis that no studies show the long term harm?

I am reminded of the published and somewhat satirical commentary that there are no double blind placebo controlled studies of parachute efficacy either.

In drugs we have long term monitoring of side effects through various mechanisms. GET does not. Nor do psychotherapeutic strategies.
We do however have patient surveys showing about half the patients report harm. Some of the GET studies also show a decline in activity levels overall. That is a harm in my view.

We also have studies showing massive declines in physical capacity. Someone at Workwell has said they will not do a long term GET study ala PACE as its highly unethical, though I forget who. They have however many cases of patients who have been tracked with various exercise programs. There are patients who show long term decline in energy output. They are themselves working on ways to engage with exercise to help manage ME better but they are not doing anything like GET is considered to be.

In ME and CFS I personally regard loss of energy in the long term as a harm, regardless of other considerations and risks. If a person is down to a low percentage functional capacity, and your therapy slashes that, how is that not harm?

My point in the original comment is this is an angle we need to work on in advocacy, that there is abundant evidence of harm, and that we need to find ways to emphasise this.

Finally there are many patient reports of harm, and sometimes severe harm. This has not been adequately investigated, so there are no large studies supporting this.

The tobacco lobby spent decades saying there was no definitive proof of harm from tobacco smoke. They were right. Yet there was lots of evidence.

The onus of proving lack of harm with pharmaceuticals is on the manufacturer/owner/developer. It should be the same with therapies when there is highly pervasive anecdotal evidence of harm, including many medically investigated cases.

I regard GET for ME as an accepted but dangerous therapy. There are no good studies showing otherwise. There is lots of physiological data backing this.

If we need a large dbpcRCT to show PACE style training is safe, using advanced physiological testing, something is deeply broken with medical research. Which might well be the case, especially in psychiatry.

 

I think I'd agree more with the point that it's worrying that we do not have good evidence of safety, rather than that there is abundant evidence of harm. I think that there is good reason to be critical of people making exaggerated claims about the safety of GET.

I think that a vital part of effective ME/CFS advocacy is to push against people making exaggerated claims about the evidence, and that means it's worth us also being cautious in claims that are made about possible harm from GET when the evidence here is still really disputable. From what I've seen, strong claims about GET leading to harm are not a useful tactic for advocacy attempts aimed at those who want to check the evidence for themselves.

 

Quite. Which is why I feel that where there are documented cases of suspected harm, albeit anecdotal at that point, if a more rigorous study were to follow those up, and try to apply some scientific investigations into them, maybe something might come of that. I mean, what happens if a drug starts getting widely reported as causing severe subjective side effects? Is that just ignored? What is done in such cases, that could not be done here?