Thesis An experimental study investigating the link between symptom reporting and heart rate variability in CFS patients, 2023, Dest & Grosemans

[Dolphin]

https://documentserver.uhasselt.be/bitstream/1942/41042/1/1b9fa48e-2513-4665-8ba1-a6b1eb7f2056.pdf

Master thesis

An experimental study investigating the link between symptom reporting and heart rate variability in chronic fatigue syndrome patients

Jentro Dest
Daan Grosemans

.Abstract

Background:

Chronic fatigue syndrome (CFS) is characterized by chronic physical and cognitive fatigue.

Studies showed that psychological and physiological dysfunctions can play a role in its pathology.

Objectives:

This study aimed to explore the altered symptom perception and autonomic nervous system dysfunction in patients via laboratory and daily life measurements

Methods:

We included five CFS patients and seven healthy controls (HC).

We assessed daily life symptoms via experience sampling method.

In the laboratory, we assessed fatigue via the Fatigue and energy scale, stress via a visual analogue scale and heart rate variability (HRV).

We performed all measurements in rest and in an exercise condition.

Results:

This study found that CFS patients had higher resting heart rate (HR) and reduced heart rate variability (HRV) during activity.

Before and after exercise, there was a negative correlation between HRV and mental loss of energy (LOE) and cognitive function.

CFS patients experienced increased mental LOE and physical fatigue at rest and following exercise.

Prior to and after laboratory tests, they had heightened general physical fatigue, mental LOE, physical LOE, and cognitive function loss.

Conclusion:

This study emphasizes the interaction between psychological and physiological components while revealing the complicated CFS symptomatology in their daily life and during laboratory testing.

Understanding the complex interactions between symptoms and HRV offers new perspectives on the complex nature of CFS, which could lead to better diagnosis and treatment strategies.

Keywords: Chronic fatigue syndrome (CFS), laboratory, real-life, Heart rate variability (HRV), fatigue, stress.

https://twitter.com/user/status/1712249536498856016

 

[Hutan]

Methods

In the laboratory, we assessed fatigue via the Fatigue and energy scale, stress via a visual analogue scale and heart rate variability (HRV).

Results

This study found that CFS patients had higher resting heart rate (HR) and reduced heart rate variability (HRV) during activity.

Before and after exercise, there was a negative correlation between HRV and mental loss of energy (LOE) and cognitive function.

CFS patients experienced increased mental LOE and physical fatigue at rest and following exercise.

Prior to and after laboratory tests, they had heightened general physical fatigue, mental LOE, physical LOE, and cognitive function loss.

Keyword

Chronic fatigue syndrome (CFS), laboratory, real-life, Heart rate variability (HRV), fatigue, stress.

'Stress' was measured. There wasn't anything interesting enough to say about stress in the Results section of the abstract. But still, of all the possible key words, 'stress' made the cut.

 

[SNT Gatchaman]

The MAST started with a five-minute preparation phase during which we explained the task to the participants. Then, a ten minute stress-inducing phase started. During this phase, subjects alternatively performed a mental arithmetic task and a hand immersion task. The mental arithmetic task consists of counting aloud backwards from 2043 in steps of 17 as quickly and precisely as possible. Each time the participant would make an error, he or she received negative feedback and was instructed to restart at their previous correctly stated answer.

During the hand immersion task, participants needed to immerse their left hand in cold water of 6°C. Participants were not told how many trials there would be. They were informed that the computer would select the length of the two different trials randomly and that the duration would vary between 45 and 90 seconds. However, in reality, the order and duration of the trials was fixed. Five hand immersion trials (HI) and four mental arithmetic trials (MA) were alternated in the following sequence and length: HI (90 s), MA (45 s), HI (60 s), MA (60 s), HI (90 s), HI (90 s), MA (45 s), HI (60 s).

Participants continued with either task until the computer gave them a sign to start with the next task. Participants were also informed that they would be videotaped in order to evaluate their facial expressions later on and that they had to look into the camera while performing the test. However, the only reason why this was done was to deceive the subjects in order to add a social stress component. Neither the participants nor the face expressions were ever filmed and analyzed at any point in time. After the stress-induction phase, a 55-minute recovery phase started.

To determine subjective stress responses, participants rated the stressfulness, painfulness, and unpleasantness of the stress induction procedure on a 100 mm visual analogue scale (VAS) with anchor 0 "not at all" and 10 "extremely"

patients experience higher physical fatigue, a higher mental LOE, more brain fog, more loss of cognitive function and more stress compared to the HC during their daily life when they performed any physical or mental activity.

In contrast, we failed to find a significantly greater increase in physical fatigue and loss of physical energy levels from baseline to exercise in patients compared to healthy subjects in both daily life and a laboratory setting. These results were contrary to our expectations. Previous studies often reported about the role of post-exertional malaise (PEM) as a characteristic symptom of CFS patients in comparison with healthy persons. It is possible however that the time period that we took into account to study post-exercise symptomatology, was too limited. We performed symptomatology measurements immediately after the cycling task

Who is responsible for this garbage?

One strength of this study is that CFS patients are included through evaluation by internists and psychiatrists with expertise in fatigue assessments according to the 1994 Centre of Disease Control and Prevention Fukuda criteria.

First and foremost, we extend our appreciation to Prof. Dr. Katleen Bogaerts for providing us with the opportunity to work on our thesis within her research group. Additionally, we would especially like to acknowledge the support and guidance of our thesis supervisor, Msc. Ynse Dooms, who provided invaluable feedback throughout the research process. Furthermore, Dr. Maaike Van Den Houte deserves special recognition for her assistance with data analysis.

 

[Sean]

Previous studies often reported about the role of post-exertional malaise (PEM) as a characteristic symptom of CFS patients in comparison with healthy persons. It is possible however that the time period that we took into account to study post-exercise symptomatology, was too limited. We performed symptomatology measurements immediately after the cycling task

Anybody not using a repeat test/measurement protocol, or using Fukuda criteria, in 2023 is not to be taken seriously. The delayed aspect of PEM has been noted for decades. There is just no excuse for not controlling for it.

They didn't find it, because they didn't look for it.

 

[duncan]

Who is responsible for this garbage?

Master thesis

Kids.

 

[SNT Gatchaman]

Yes, I was referring to the supervisors.

 

[rvallee]

'Stress' was measured. There wasn't anything interesting enough to say about stress in the Results section of the abstract. But still, of all the possible key words, 'stress' made the cut.

They seem to be using stress where either exertion or strain would make more sense. Pretty much 99% of the time when stress is used in a medical setting, it would be better replaced with exertion, and here is no exception.

I used strain above in the sense of burden, mostly because I've been using a WHOOP device for 2 months and that's the measure of total exertion they use. I found that it matches my experience of how much I exerted throughout the day. As does my HRV. The strain measure is a mix of pulse rate, HRV, resting heart rate and activity levels.

I've been getting a lot of help in those 2 months and made significant improvements. I also saw my HRV rise significantly in that time span, and having stabilized in recent weeks, it mostly goes up and down depending on my daily strain, how much I exerted and well I recovered, having a lot to do with how good my sleep was. My average and resting heart rates have also dropped significantly, although I think mostly from dietary changes, making sure I take plenty of sodium and a good balance of electrolytes to match.

WHOOP uses a strain calculation that goes from about 4 (I don't think it's possible to get a zero, usually wake up around 4-5) for total immobile rest up to 21, with anything above 14 being overreaching, the equivalent of a whole day of arduous physical labor, and anything above 18 being unsustainable for more than a few days. I find that this strain measure quite matches up with how worn out I feel at the end of the day.

I barely do anything on most days, and my average is 14.8. In the first few weeks when I did even less, it was around 7-8. I've resumed cleaning up a bit, doing dishes, preparing my meals, going upstairs to eat dinner. Then I was able to go out of the house a bit. I often hit 15+ and once hit 17.5, despite being barely more active than an average 80 year-old. 15+ at my age would normally be a high activity day, with lots of work, activity and no or barely any rest throughout.

My HRV now averages around 72, from an early 40, then 64 the next month. I have zero 'stress' in the typical psychosocial sense. This is all exertion, mental and physical. Stress is mostly a useless term for the most part here, other than in adding exertion. It really seems like medicine isn't able to accept that mental exertion is not inherently different from physical exertion, there is no separate supply of energy for it, and neurons can tire out just as well as muscles, just differently. Emotions aren't some special category either, they function and use energy and metabolites the same way as classical 'thinking' does.

My symptoms have improved quite a lot along with my HRV, and match drops quite well. It's sad that they botched up this study, they just seem to be looking at it from the wrong angle, and with far too much bias in trying to cram in some psychosomatic ideas about 'stress' having a different meaning than exertion, even though it perfectly substitutes.

I'm really not sure how this was approved as a Master's thesis. Master's is not the right level to do original studies like this, although the fact that it's not particularly worse than the average research out there speaks a lot more about the general state of non-pharmaceutical clinical research than anything else. I predict a good future for this person in evidence-based medicine, things really at that bad out there, the blind teaching the blind about all the things they've never seen.

 

[Hutan]

They seem to be using stress where either exertion or strain would make more sense. Pretty much 99% of the time when stress is used in a medical setting, it would be better replaced with exertion, and here is no exception.

Yes, I think the concept was quite muddled here. The measure of 'stress' was a visual analogue scale, so presumably something like, 'on a scale of 1 top 10, how stressed do you feel?'. And they seemed to do things that they thought would specifically increase psychosocial stress including giving negative feedback and suggesting people would be judging the participants' facial expressions.

It's sad that they botched up this study, they just seem to be looking at it from the wrong angle, and with far too much bias in trying to cram in some psychosomatic ideas about 'stress' having a different meaning than exertion, even though it perfectly substitutes.

Yes.

This study found that CFS patients had higher resting heart rate (HR) and reduced heart rate variability (HRV) during activity.
Before and after exercise, there was a negative correlation between HRV and mental loss of energy (LOE) and cognitive function.

This was an interesting result, although the sample size is tiny. The findings are commonly reported in ME/CFS, and the way it varies over short spaces of time maybe means that it isn't just a result of physical fitness.

 

[rvallee]

stress including giving negative feedback and suggesting people would be judging the participants' facial expressions

How does that amount to stress? Almost without fail, where 'stress' is used to mean something else than exertion, and the same is true about almost all uses of anxiety, you can perfectly substitute with "I don't like this situation". Which, in my opinion, is a perfectly reasonable take most of the time. There are many good survival reasons to want to get out of situations one doesn't like.

The words used in mental health had to be stripped of all meaning so they could be crammed in as puzzles pieces for old psychosomatic beliefs. And sure enough, they simply have no meaning anymore. It would be very hard to manage a more perfect way to fail not only physical health, but mental health as well. Basically everything has to be rebuilt from scratch or it just keeps getting stuck on the same loops.

And of all things, it's likely going to be machines who will manage it. Because if they don't, it sure as hell isn't going to be humans pulling it off. Long Covid has made it all clear, the endless loop of failure is truly endless. There are still too many layers of mysticism, it's going to take a full physical, down to the atom, understanding of the whole organism to achieve even a basic understanding of psychology, same as biology doesn't make sense without understanding basic physical and chemical forces, and that too will require machines anyway.

Not that it removes from it. Understanding that all the parts of nature can be explained by mathematical equations doesn't make their outcome any less seemingly magical, less grand. But without technology, magic is still the default, if not the only thing around. We just freaking love this stuff.

 

[ME/CFS Skeptic]

The thesis writes:

"The study topics and research questions were determined in collaboration with Msc. Y. Dooms and Dr. Maaike Van Den Houte. Due to the fact that the study was a component of an ongoing research project, we were not involved in decisions about research design or methodology"