Short-Term Effect of Aerobic Exercise on Symptoms in Multiple Sclerosis and Chronic Fatigue Syndrome

Dolphin

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Dolphin said:
As one can see, there are some changes for fatigue and pain in the CFS group compared to the healthy controls which might reach statistical significance with a bigger sample.
Some of the standard deviations (SDs) are enormous, aren't they? Stats are my weakest point in science :redface: but I know there are some stats whizzes on here.
Like you suggest, the SDs are very big which affects the likelihood that statistically significant differences are found.

If one looks at it in percentage terms, the pain levels in the CFS group at two hours after are nearly double what they were at baseline (18.9 vs 34.5).

Compare that to what happened in healthy controls (8 vs 7.75).
 

alex3619

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Five people did not meet the SATET requirements, they were unable to comply. I might have missed it, but who were those five people? In which groups?

Oops, here:

Two participants with MS (EDSS = 6; Karnofsky score = 70) and three participants with CFS (Karnofsky score = 60 [n = 1], 70 [n = 2]) were unable to maintain the desired wattage to achieve a 90% work rate; however, they completed the exercise test to the best of their ability.

Three out of eight ME/CFS patients could not perform the test as required.
 

daisybell

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At a quick glance it looks to me like the pain and fatigue scores would have been statistically different at the two hour point... Why I wonder have they not done this analysis?

This study is so flawed I am surprised it was published.
 

Sidereal

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Pain and fatigue scores clearly increased in ME and MS groups after exercise but they couldn't detect a statistically significant effect with such a minuscule sample size (type II error). It would have been more appropriate to use non-parametric statistics with these data anyway. Reviewers were asleep I guess. Very inappropriate and overreaching conclusions and abstract.
 

anciendaze

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...Three out of eight ME/CFS patients could not perform the test as required.
This is a joke, right? You run a test on eight people, three of which don't complete the test, and then report the effects on an entire class of patients given the same diagnosis by doctors who probably don't understand the condition in the first place.

I will also reiterate my statements that mean and SD only define a distribution if it is known to be Gaussian. Should it be a Levy distribution there may not be any meaningful SD, only an artifact of bounds and number of samples. What we have here is a group which was able to do a little arithmetic and decided this must result in meaningful numbers, despite having 37% of their tiny sample missing from results.

Let's scale this up to make it more dramatic. Imagine running a test with 100 patients in which 37 were not able to complete the test because they collapsed. Are you then going to recommend doing this to several million because the consequences were negligible?
 

alex3619

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Given that the patients were probably mild or moderate, not severe, as we rate ME patients, and three in eight could not perform, its an even worse result than it at first appears.

What it raises is the possibility, not probability, that there are subgroups who do respond to exercise. Further research is required.

I am glad they used the CCC though. All studies should do this.
 

osisposis

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2012, Differences in metabolite-detecting, adrenergic, and immune gene expression following moderate exercise in chronic fatigue syndrome, multiple sclerosis and healthy controls




http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3256093/

and theres quite a bit of info. pointing to IL-10 suppressing TH17, so it seems to me that running low in IL-10 may be the culprit here. and I think it's the difference in CFS and ME/CFS.
 
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taniaaust1

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At a quick glance it looks to me like the pain and fatigue scores would have been statistically different at the two hour point... Why I wonder have they not done this analysis?

This study is so flawed I am surprised it was published.

Obviously the ones who did this study were biased and just wanted to support exercise. This study really could of been written up quite differently.

I hope the ones who did this study do not get more funding to do more biased research.
.......

Besides it is known that ME/CFS flares up 24-48 hours later and often a repeat test is needed, so this study doesnt make any sense at all if they want to say 15mins exercise sessions are safe for us
 

anciendaze

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There was a gotcha in this paper, that, so far, seems to have escaped the critics on this forum. It concerns the "sub-anaerobic exercise test" (SATET).
The SATET is based on normative data from healthy populations and was performed on an exercise cycle, with participants maintaining a wattage of 90% of their predicted work rate.
There is actually no indication of awareness that either CFS or MS patients just might have a lower anaerobic threshold for exercise. The inherent safety of the test was already proved because other researchers had used it. (Wait a minute! What are we actually testing here?) I can't find any good explanation for why about 1/3 of their patients failed to complete the initial test. (Obviously, such people are to be disregarded.)

I would also point out a fundamental contradiction in experimental design. There were using an (assumed) aerobic exercise challenge, but made no attempt to measure aerobic capacity afterward. The question of whether or not those patients who were able to complete the test gained or lost capacity for aerobic exercise simply was not addressed. The two tests of function required only the ability to stand quickly without assistance (TUG) and walk 25 feet (T25FW). Neither of these requires aerobic exercise; you could hold your breath and might even do better on the times, like a sprinter. How this translates into maintaining daily function is unclear. If you can make it out of the laboratory the researchers' job is done.

Several inferences take us from studies of the healthy population to these patient population. More inferences take us to a conclusion regarding subjective measures like rating of perceived exertion (RPE). It appears that both MS patients and CFS patients have something wrong with their perception, not physiology:
Thus the results imply that those with MS and CFS perceive their effort during exercise differently from a healthy population.

There is even an internal contradiction in the logic. Patients have a problem with perceived exertion which doctors can't measure. Overexertion may cause relapse. How are patients to limit exercise safely if they can't tell when they are approaching limits?

Lets go back to consider those patients who were unable to maintain the required heart rate for 90% of predicted work rate (power output). How did researchers get those predictions? They used a crude rule of thumb for the healthy population, HR = 220 - age. Never mind that both groups of patients suddenly began to behave like people many years older at disease onset. The idea that these patients had problems maintaining exercise, and reported higher levels of perceived exertion because anaerobic thresholds were in fact different in illness, was simply ignored. ("It is so much simpler to compute 220 - age.") There is simply no awareness that those who could not complete the test as prescribed just might have lower thresholds than healthy people.

So, how do they know the exercise challenge was actually sub-anaerobic? It was labeled as such, and other researchers were of the same opinion.

("See, it says sub-anaerobic right on the box, and prominent doctors endorse it on TV.")

My opinion of this work is so negative that I have to ask others here to check that I have not allowed emotion to carry me beyond facts stated in the paper.

I confess that I am already imagining new publications with titles like "Demyelination as a Consequence of False Illness Beliefs".
 
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MeSci

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There were using an (assumed) aerobic exercise challenge, but made no attempt to measure aerobic capacity afterward. The question of whether or not those patients who were able to complete the test gained or lost capacity for aerobic exercise simply was not addressed. The two tests of function required only the ability to stand quickly without assistance (TUG) and walk 25 feet (T25FW). Neither of these requires aerobic exercise; you could hold your breath and might even do better on the times, like a sprinter. How this translates into maintaining daily function is unclear.

I had wondered whether they had relied entirely on subjective or even non-existent evidence for whether exercise was aerobic or otherwise. So it appears that they did.

It appears that both MS patients and CFS patients have something wrong with their perception, not physiology:

Thus the results imply that those with MS and CFS perceive their effort during exercise differently from a healthy population.

I am fairly sure that at least one other study (Newton? Snell?) found that patients' perceptions of maximal effort were accurate.
 

MeSci

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I think there is something wrong with the perception of some doctors. They think there GOD and know everything of the body. What they don't understand is all in the mind of the patients. Yeah right!

I'd say that was the case for a very high percentage of doctors, unless I have been unfeasibly unlucky.

But as far as I can see, only one of the authors of this study is a doctor; the others appear to be bona fide scientists (e.g. with doctorates, not to be confused with doctors who generally have low academic qualifications).
 

anciendaze

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This study used the talents of 5 PhDs and one MD. Before you get overly impressed with authority I will offer this insight from one of my private correspondents who used to serve as an adviser on statistics for PhD. candidates. Here is a fragment of an exchange:
...I had a researcher who had two groups of rats, one control and one experimental. All of the experimental animals died and all of the control animals lived. He wanted to know if there was statistical significance.

Sounds like sadistical significance.
 

alex3619

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@anciendaze , on the anaerobic threshold issue I have had the same thoughts. I do not think you have a distorted argument. The whole reason for estimated AT was that it was cheap and easy. Yet we still use measured AT, because calculated AT is unreliable in sick people. Yet its the calculated AT that became popular, because it allowed for simplified testing (the Bruce Protocol) at doctor's clinics with not much equipment. So they are basically going with the cheap popular testing, rather than the accurate testing.

Cost is a factor, but I wonder how much of one? CPET appears to cost up to 10x more in the US. Recently I heard the claim that qEEG is up to $10,000 in the US. I just confirmed that here it costs $300, using the same analytical software, though I cannot speak to whether or not the diagnostic protocol is the same. I am guessing that in much of the world a qEEG test is not that expensive. Its the same for CPET.
 

anciendaze

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@alex3619

We keep getting the cart before the horse. The cost of widespread deployment of an exercise protocol is very different from the cost of research validating a particular aspect of exercise intolerance. Previous arguments have gone round and round on the subject of subjective distortion by ME/CFS patients, with some convinced this is "obvious" and denying there is any physiological impairment. (Even tacitly accepting this argument leaves the question of how patients can avoid crossing thresholds they cannot accurately perceive.)

I'm afraid the real argument about costs concerns the consequential costs of finding physiological measures backing disability claims.

Rather than go another round in the ring in this contest, concerning various claims about subjective distortion, I would suggest we ask if perceived effort correlates with measured anaerobic threshold. This at least addresses two subjects different researchers consider measurable.
 

Valentijn

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I am fairly sure that at least one other study (Newton? Snell?) found that patients' perceptions of maximal effort were accurate.
My perception of maximal effort was certainly accurate. Respiratory Quotient (RQ) of 1.1 indicates maximal effort, and I pushed myself to 1.23.

And then I spent 15 minutes sitting on the floor, followed by 2 weeks of a crash :rolleyes: Oh, and the worst symptom of all - an incessantly twitching thumb for over a week from gripping the handlebar during the CPET! I couldn't do much of anything on my laptop :meh:
 

biophile

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Learmonth said:
This study provides important messages for those with MS and CFS and for health professionals involved in their care. Undertaking aerobic training on a stationary cycle for 15 minutes at a work rate sufficient to produce an HR of about 66% to 70% of the maximum age-predicted HR and an RPE of about 4 does not significantly affect pain and function in people with MS and CFS.

Simon said:
Think they are getting well ahead of themselves ...

I would go further and say its a dangerous load of bollocks that is clearly out of touch with reality. Millions of patients, many who for example struggle to visit their own letter box without crashing or at least feeling worse, should not be expected to now pull off 15 minutes of exercise at 70% predicted HR without any problems just because a single, unrepresentative, inadequately conducted, statistically underpowered, pilot study says so, particularly if it conflicts with larger similar studies.

It is concerning that these researchers think the "important message" should now be recommended to patients and health professionals. This message would inappropriately increase expectations about exercise and doubts about symptoms.

Valentijn said:
And then I spent 15 minutes sitting on the floor, followed by 2 weeks of a crash.

No, that's impossible, this study says there aren't any problems, your experience must have been pure coincidence! :p
 
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SOC

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Short-term effect of aerobic exercise? This relates to ME/CFS how? We know PEM, which is a required feature of CCC ME/CFS, can take days to show up. Shouldn't they have evaluated symptoms up to and beyond the time period known for the damage to occur? Isn't this rather like saying it's safe to give people poisons as long as they don't have symptom changes in the first few hours? o_O
 

MeSci

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This study used the talents of 5 PhDs and one MD. Before you get overly impressed with authority I will offer this insight from one of my private correspondents who used to serve as an adviser on statistics for PhD. candidates. Here is a fragment of an exchange:


Sounds like sadistical significance.

Oh yes, I don't automatically assume that PhDs know what they are doing/talking about! They are just generally better educated.

But I have been critiquing scientific papers for a long time, whoever has written them, and arguing with scientists and academics. Started at an early age, to the annoyance of adults! :D

I was just trying to clarify the difference between doctors and scientists, as many people seem to get them mixed up. There is a little overlap, but from my dealings with doctors most know little about medical science - even top 'experts' in their own fields!
 

ukxmrv

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This study was funded by the National Health Service Ayrshire and Arran, Bevan Endowment Fund, Ayrshire and Arran Branch of the Multiple Sclerosis Society, and by a grant from the Medical Development Fund, University of Glasgow.

and an earlier paper by one of the authors


Comparing Two Conditions of Administering the Six-Minute Walk Test in People with Multiple Sclerosis
Brian M. Sandroff, Lara A. Pilutti, Deirdre Dlugonski, Yvonne C. Learmonth, John H. Pula and Robert W. Motl
International Journal of MS Care, Vol. 16, No. 1 (Spring 2014) pp. 48-54
Abstract | Full Text | PDF (649 KB)
 
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