..Oxidative Stress, Exercise, and Pain in Health and Disease: Potential Role of Autonomic Regulation and Epigenetic Mechanisms, 2020, Hendrix et al

[Andy]

Full title: The Interplay between Oxidative Stress, Exercise, and Pain in Health and Disease: Potential Role of Autonomic Regulation and Epigenetic Mechanisms

Oxidative stress can be induced by various stimuli and altered in certain conditions, including exercise and pain. Although many studies have investigated oxidative stress in relation to either exercise or pain, the literature presents conflicting results. Therefore, this review critically discusses existing literature about this topic, aiming to provide a clear overview of known interactions between oxidative stress, exercise, and pain in healthy people as well as in people with chronic pain, and to highlight possible confounding factors to keep in mind when reflecting on these interactions. In addition, autonomic regulation and epigenetic mechanisms are proposed as potential mechanisms of action underlying the interplay between oxidative stress, exercise, and pain. This review highlights that the relation between oxidative stress, exercise, and pain is poorly understood and not straightforward, as it is dependent on the characteristics of exercise, but also on which population is investigated. To be able to compare studies on this topic, strict guidelines should be developed to limit the effect of several confounding factors. This way, the true interplay between oxidative stress, exercise, and pain, and the underlying mechanisms of action can be revealed and validated via independent studies.

Open access, https://www.mdpi.com/2076-3921/9/11/1166/htm

 

[Woolie]

Just a note that mdpi journals (where this was published) are widely considered to be predatory. That is, they make their money out of stalking researchers and academics on the internet, and getting them to part with money in return for a "peer reviewed" publication.

The clue is in the emphasis on advantages for authors - with almost no mention of readers - at their website. Here are the top features of "Acoustics", for example:

• Reliable Service
• Rapid Publication
• Recognition of Reviewers (okay not this one so much)
  
• Extra Benefits (no space limits)

This doesn't mean every article in them is rubbish, of course. It just means either the author didn't know/got conned, or had trouble getting published elsewhere.

 

[Andy]

Given that the authors write, in part,

Taken together, these findings suggest an involvement of oxidative stress mechanisms in the pathophysiology of such conditions. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM)—two conditions in which widespread persistent pain is a defining symptom—have been extensively investigated with regard to oxidative stress. Research showed evidence of increased oxidative stress in both patients and animal models (for a review, see [7,8]). Complex conditions such as ME/CFS and FM are very challenging to be translated in animal models given the poor understanding of their etiology (for a review, see [102,103]). However, animal models mimicking the most important features of FM, including depressive- and anxiety-like symptoms, have recently been proposed [104,105,106]. In the reserpine-induced FM model, parameters indicative of oxidative stress were found to be altered in cerebrospinal fluid (CSF) [107], brain tissue [108], spinal cord, and muscles [105].

I'm not expecting the rest of the paper to be of any more value than that section which casually conflates ME with FM.

 

[ME/CFS Skeptic]

It just means either the author didn't know/got conned

But the journal and the article are registered on Pubmed, so people will find it if they search for topics or if they have an email notification for papers on ME/CFS - as I do. So not sure if one could say that the authors were conned to publish in an MDPI journal. It's probably not their first choice, but don't know if it is such a bad deal for them.

 

[DMissa]

Just a note that mdpi journals (where this was published) are widely considered to be predatory. That is, they make their money out of stalking researchers and academics on the internet, and getting them to part with money in return for a "peer reviewed" publication.

The clue is in the emphasis on advantages for authors - with almost no mention of readers - at their website. Here are the top features of "Acoustics", for example:

• Reliable Service
• Rapid Publication
• Recognition of Reviewers (okay not this one so much)
  
• Extra Benefits (no space limits)

This doesn't mean every article in them is rubbish, of course. It just means either the author didn't know/got conned, or had trouble getting published elsewhere.

This is not necessarily the case. Many of the biomedical MDPI journals have high impact factors and are considered reputable, and some of them are *not* easy to publish in. Publishing in an impact factor 4.5 paper is not really settling for less, that's actually pretty good. Especially in ME/CFS where "broad appeal" is an issue which impairs publishability in "prestige" journals. Papers under the Nature stable of journals which are often posted here have scores in this range, or even lower.

In my experience with these journals the peer review process has also been normal - nothing fishy.

MDPI has hundreds of journals, which obviously vary in their editorial quality due to the large number of them. They should be assessed on a journal-by-journal basis. They are not run by the same people.

The dot points are just marketing gimmicks that even credible publishers employ to attract applications and do not, alone, mean that the journal is predatory.

I get harassed to publish by predatory journals probably 15 times per week and MDPI journals have never been among them - and I wouldn't expect them to be.

Not shilling for any particular publisher - it would be bad for me to do so and I have no reason to. But it's good to look at the journal on its own.

Publication charges are also normal in science. And they get higher the more prestigious the journal is!

 

[Woolie]

@DMissa, I agree that there are ones out there that are way worse. But here are a few of my unsolicited emails from mdpi in the last few weeks:

Gentle Reminder: [IJERPH] (IF: 2.849, ISSN 1660-4601) Invitation to be the Guest Editor of the Special Issue on "Advances in XXXX"

XXX was a phrase from my ResearchGate page, which stated three broad areas I work in. They are three areas that very few people combine, so it was clear they had found this phrase. by trawling my ResearchGate page.

Call for Paper Reminder: [Cancers] (IF: 6.126, ISSN: 2072-6694) — Special Issue "Brain Metastases (Secondary Brain Tumor)"

[Brain Sciences] Impact Factor 3.332 - Invitation to Submit a Paper with 20% discount on Article Processing Charge

The tone of all these "invitations" was quite insistent, often of surprise that I hadn't replied to their earlier invitations. The invitations also included misrepresentations of the reasons they were asking me. Usually a mention of a publication I've done, which had obviously been found by a bot. It's clear they had no particular understanding of what was in the paper they quoted, or what I did more generally.

During the same period, I had no solicitations from any Elsevier, Sage, or Taylor and Francis journals, or from any of the PLOS journals, or from any journal run by a professional organisation.

I agree the mdpi impact factors often look high, but given this publisher appears eager to take submissions from me in areas of which I know nothing (e.g., metastatic brain tumours), that speaks in louder volumes to me than the IF, which can be gamed (games like inserting references to the journal's previous articles into the references lists).

It is in principle possible that they solicit widely, but then only take the highest quality. But that does not fit with the evidence suggesting their acceptance rates are generally very high (e.g., here)

Again, I'm not saying the articles in these journals are all without merit. As @Michiel Tack points out, there might be good reasons why good work might appear there - like an inability to get it published elsewhere due to political factors.

 

[Woolie]

PS It just occurred to me that another reason mpdi might be a bit loose and free in their soliciting behaviour is that the more submissions they get overall, the more they can afford to decline - which will enhance their acceptance rate statistics, making the journals look more "discerning".

They just don't take into account what a bad impression the indiscriminate "invitations" create at our end.

Its also worth noting that a lot of their solicitations to me take the form of inviting me to guest edit. This is essentially a pyramid selling scheme, because I benefit from free publication in the journal, and then I am motivated to use my contacts, influence and goodwill to invite colleagues to submit for the special issue (and of course pay full charges).

 

[DMissa]

@DMissa, I agree that there are ones out there that are way worse. But here are a few of my unsolicited emails from mdpi in the last few weeks:

XXX was a phrase from my ResearchGate page, which stated three broad areas I work in. They are three areas that very few people combine, so it was clear they had found this phrase. by trawling my ResearchGate page.


The tone of all these "invitations" was quite insistent, often of surprise that I hadn't replied to their earlier invitations. The invitations also included misrepresentations of the reasons they were asking me. Usually a mention of a publication I've done, which had obviously been found by a bot. It's clear they had no particular understanding of what was in the paper they quoted, or what I did more generally.

During the same period, I had no solicitations from any Elsevier, Sage, or Taylor and Francis journals, or from any of the PLOS journals, or from any journal run by a professional organisation.

I agree the mdpi impact factors often look high, but given this publisher appears eager to take submissions from me in areas of which I know nothing (e.g., metastatic brain tumours), that speaks in louder volumes to me than the IF, which can be gamed (games like inserting references to the journal's previous articles into the references lists).

It is in principle possible that they solicit widely, but then only take the highest quality. But that does not fit with the evidence suggesting their acceptance rates are generally very high (e.g., here)

Again, I'm not saying the articles in these journals are all without merit. As @Michiel Tack points out, there might be good reasons why good work might appear there - like an inability to get it published elsewhere due to political factors.

Hmm, yes you are of course right with a lot of this - I think it goes back to what I initially suspected: there is variation from journal to journal. Perhaps just moreso than I had thought.

I had read the open letter by Dan Brockington too, I remembered it saying something along the lines of the more highly ranked journals of theirs having lower acceptance rates. I guess the take-home stays the same, we just have to judge things on an individual basis.

At the end of the day, you can have good science in a less reputed journal, and bad science in Nature. So it just comes back to focusing on the science itself .

The tone of all these "invitations" was quite insistent, often of surprise that I hadn't replied to their earlier invitations. The invitations also included misrepresentations of the reasons they were asking me. Usually a mention of a publication I've done, which had obviously been found by a bot. It's clear they had no particular understanding of what was in the paper they quoted, or what I did more generally.

Dear eminent researcher, we require your contribution to an upcoming issue of the Journal of Muscularneurochemical Medicinal Fingerpainting and Medicinal Medicine within one week!!!! Gotta love them.

 

[ME/CFS Skeptic]

Quote from the paper:

Of important note, oxidative stress has classically been seen as a dangerous phenomenon [24]. Antioxidant supplementation is commonly used among athletes and physically active people in the attempt of reducing exercise-induced oxidative stress and increasing performance. However, its benefits are unclear [75–78]. It is possible that antioxidant supplementation mitigates the above-mentioned endogenous coping mechanisms which are activated via oxidative eustress [65,79]. A recent study even demonstrated that moderate training is more beneficial than selenium supplementation (an antioxidant), improving the antioxidant status and decreasing exercise-induced oxidative damage [80]. Therefore, moderate and controlled physical activity should be considered as a valuable strategy to promote desirable changes in the balance between pro- and antioxidant products.

 

[ME/CFS Skeptic]

If I understand correctly the authors argue that "although the underlying mechanisms are poorly understood, there seems to be a relation between oxidative stress, exercise, and pain."

In ME/CFS and fibromyalgia there have been reports suggesting increased oxidative stress and failure of exercise to produce a pain-relieving effect. It seems that the authors speculate in this paper that both effects might be related to each other.