Physical Activity And Sleep Patterns Following Physical And Cognitive Challenge In Patients With CFS

[Dolphin]

http://journals.lww.com/acsm-msse/F...Basic_Science_World_Congress_Poster__.16.aspx

Physical Activity And Sleep Patterns Following Physical And Cognitive Challenge In Patients With Chronic Fatigue Syndrome.

Andrew Keech, Ute Vollmer-Conna, Benjamin Barry, Andrew Lloyd.

University of New South Wales, Sydney, Australia.

Email: andrew.keech@unsw.edu.au

(No relationships reported)

Chronic fatigue syndrome (CFS) is a disorder characterised by profound fatigue which is not relieved by rest and can be exacerbated by physical or cognitive activity.

Patients generally report poor sleep and being less physically active than pre-illness; little is known how this is affected by exertion.

PURPOSE:

To characterise sleep and physical activity patterns in patients with CFS during the post-exertional exacerbation of fatigue following physical and cognitive challenge.

METHODS:

Two studies were conducted: a physically-demanding challenge (moderate-intensity aerobic exercise; EXER), and a cognitively-demanding challenge (simulated driving; COG).

Each study included a well-characterised sample of patients with CFS (EXER: N=10; COG: N=11) and healthy matched control participants (EXER: N=12; COG: N=11).

In each study, self-reported ratings of fatigue and symptoms were obtained at baseline and at time-points in the first 24 hours post-challenge.

A triaxial accelerometer was worn for a 24 hour baseline period and the first 24 hours following each challenge.

RESULTS:

Patients with CFS reported substantial fatigue, functional impairment and poor sleep at baseline in each study (all p<0.02).

Patients displayed comparable performance to control participants during each challenge, but reported higher perceived exertion (p<0.02).

Each challenge induced an immediate exacerbation of fatigue in patients (p<0.02), which was maintained 24 hours following.

Patients displayed longer night-time sleep (overall mean CFS: 8.9±1.1 hrs/night, controls: 7.5±1.2 hrs/night, p<0.001) and more time spent lying down during waking hours (overall mean CFS: 29±15%, controls: 14±10%, p<0.001).

Patients’ sleep duration and activity patterns were not affected by either challenge, excepting a trend towards less movement (p=0.06) and more lying down (p=0.07) following the exercise challenge.

Patient’s fatigue at baseline correlated with a more severe reduction in movement during waking hours following the challenges (r=-.58, p=0.006).

CONCLUSION:

Patients with CFS displayed low levels of daytime physical activity and excessive night-time sleep at baseline.

Despite the exacerbation of fatigue by both exercise and cognitive challenge, patients’ physical activity patterns were not significantly affected.

Individual differences in post-exertional change in physical function were linked to baseline levels of fatigue.

 

[Dolphin]

Patients’ sleep duration and activity patterns were not affected by either challenge, excepting a trend towards less movement (p=0.06) and more lying down (p=0.07) following the exercise challenge.

Given the sample sizes, those results shouldn't lead one to accept the null hypothesis.

It would be interesting to see what the effect sizes were to see how interesting or otherwise these particular findings are.

 

[alkt]

people who have problems with fatigue rest for longer periods and do less. they were actually taking grant money to prove the obvious.that money could of been better spent elsewhere.is this post just to wind people up.

 

[SOC]

Each study included a well-characterised sample of patients with CFS...

I have to laugh (bitterly) when they say this. How can they have a well-characterized sample when we don't even have a single clear definition? They shouldn't be saying they have "a well-characterized sample", they should be telling us which definition they used so we know to which group the research might apply.

If they were going to do damaging testing (moderate intensity aerobic exercise and a demanding cognitive challenge ) then they might as well have used the 2-day CPET.

I know it's hard to do decent research without reasonable funding, but I'm not sure research with ill-defined cohorts and questionable conclusions does us any good. Better the money spent on these studies be pooled into a single substantive research study.

With luck, these researchers will learn more about ME/CFS and do more valuable research in the future.

 

[Sean]

I know it's hard to do decent research without reasonable funding, but I'm not sure research with ill-defined cohorts and questionable conclusions does us any good. Better the money spend on these studies be pooled into a single substantive research study.

This.

Enough with the statistically sub-par studies. Sample sizes of 10-12?

 

[TiredSam]

a physically-demanding challenge (moderate-intensity aerobic exercise)

Are they completely insane?

 

[Kati]

i have done 3 CPET so far since onset of my illness.

i can say for sure that post exertional relapse leads at least for me to poorer quality of sleep. And decreased cognitive and physical functioning. It works like a clock every single time.

Now if we could please have a homogenous cohort, large sample, quality measurement which includes EEG, imaging, and blood measurement, we could put this to rest for sure.

 

[Valentijn]

Stupid timing on the accelerometer use. By starting use immediately following exertion, and ending 24 hours later, they are looking at the OI/exercise intolerance period. PEM would've just been starting up at the same time that the accelerometers finished collecting data.

They sound like a bunch of people who have no idea what ME or PEM is. The lead author is a "chronic fatigue" researcher, which really says it all I suppose. It looks like they've done some intelligent stuff in the past, but they really need to learn about a disease before attempting to research it.

In the hope that they do read this:

1. Use a real ME definition. PEM is mandatory. It typically starts 24 hours after exertion, lasts for days or weeks, and features the exacerbation of neurological, immune, and muscular symptoms which have nothing to do with "fatigue". If you want ME patients, doctors, or researchers to take you seriously, use the Canadian Consensus Criteria or International Consensus Criteria to select patients. If your funding depends on using Fukuda or the Australian equivalent, you still need to select only patients who have PEM.
   
2. Use a big enough group to have some hope of producing relevant results. If you have 22 patients, put them all in the physical PEM group. Researchers seeking to disprove that ME is a biological disease like to use tiny samples of patients so that positive results are impossible and they can crow about having disproven some biological theory. Using tiny sample sizes looks very suspect, especially when the preliminary research has already demonstrated that PEM objectively exists and has been independently replicated by several groups.
3. Figure out what you're studying. If it's chronic fatigue, please leave ME, CFS, and ME/CFS out of it. These are entirely different illnesses. Pick one. You do not get to put CF patients in a study and claim it applies to CFS. And if you are studying chronic fatigue, then looking for exercise intolerance doesn't make any sense in the first place.

 

[Cheshire]

If they were going to do damaging testing (moderate intensity aerobic exercise and a demanding cognitive challenge ) then they might as well have used the 2-day CPET.

Here is what Dr LLoyd says about the 2 days CPET :
https://www.youtube.com/watch?t=4&v=BgWgX5F5WUM

40:25

This is described in a study where people are being encouraged in a laboratory sort of setting to do some kind of exercise like cycling or trade mill and to keep going until they really [??] and to measure how much oxygen they are consuming. That’s a measure of how metabolism in the muscles is going.

There’s a problem with studies like that, especially when they are repeated the next day and that is that it’s very hard to control some… Hum… Two issues. One is what we call volition. That is how hard you try. And the other is that there are some reflex pathways. If you have pain in your muscles, or pain in your body, it doesn’t matter how hard you try, it will impair your exercise performance. And so those two things are just impossible to control in aerobic exercises.

Twenty years ago, during my PhD, we resolved not to do exercise studies like that, because they are uninformative. And so we chose instead to do a more controlled narrow form of exercise. We just do asymmetric exercise, just like using one muscle group. We can drive the muscle voluntarily, you can drive it with electric stimuli over the [brachial?] plexus. Or you can actually drive it from a magnet on the brain. And we showed that on day one and day two, absolutely OK… Absolutely no deficit whatsoever in the muscles in the couch potatoes versus the patients

 

[Valentijn]

There’s a problem with studies like that, especially when they are repeated the next day and that is that it’s very hard to control some… Hum… Two issues. One is what we call volition. That is how hard you try. And the other is that there are some reflex pathways. If you have pain in your muscles, or pain in your body, it doesn’t matter how hard you try, it will impair your exercise performance. And so those two things are just impossible to control in aerobic exercises.

Okay, I was trying to be nice in my prior post and avoid the first adjectives which sprung to mind. But what a bleeping moron! I can understand someone not understanding how the CPET works, but how stupid do you have be to go spouting off on a subject of which you apparently have absolutely no understanding?

A maximal CPET has several ways built in to control for volition. If someone holds back, their Respiratory Exchange Rate (RER) will not exceed 1.1, heart rate won't hit predicted levels, etc, and then it's not a bloody maximal CPET at all.

I'm a lawyer with no background in medicine or biology, but apparently I know far more about maximal CPETs than a researcher and licensed MD who thinks he's an authority on the subject. Beyond pathetic. Probably just another psychobabbler who can't comprehend anything involving science.

 

[Dolphin]

These conference abstracts often lead to full papers so we may get some more information again.