Lactic acid, lactate in ME/CFS

Arfmeister said:
1) Elevated blood lactate in resting conditions correlate with post-exertional malaise severity in patients with ME CFS
Click to expand...

I am not sure how that would relate to going above an anaerobic threshold - I don't see how lactate levels at rest would reflect that.
Arfmeister said:
2) Abnormal blood lactate accumulation during repeated exercise testing in ME CFS

Abnormal lactate levels are also shown in the 2 day CPET
- mind you ME CFS patients that can do 2 day CPET are not severe, but Mild - maybe Moderate
Click to expand...

There might well be a correlation between lactate and reduced cardiopulmonary performance on day 2 but that doesn't mean that PEM is specifically linked to anaerobic threshold as far as I can see.
And, as you say, if these people were really in PEM they would not be doing a second test.
 
Jonathan Edwards said:
I am not sure how that would relate to going above an anaerobic threshold - I don't see how lactate levels at rest would reflect that.


There might well be a correlation between lactate and reduced cardiopulmonary performance on day 2 but that doesn't mean that PEM is specifically linked to anaerobic threshold as far as I can see.
And, as you say, if these people were really in PEM they would not be doing a second test.
Click to expand...
Maybe I would be the perfect test case because my AT was extremely low at 1 28 min. Only one CPET.
After doing groceries I always have a day after, off day.
When I know I should postpone my shopping because getting ready to go takes too long, chance of PEM is greater.
Muscle aches in both cases are the same, but cognitive PEM is way worse.
Lactic acid has only been tested once 14.11 and pyruvic acid 0.07 in 24 hour urine sample.
 
Ferry said:
But could it be a plausible explanation for intense burning muscle pain that is quickly triggered during routine activities and that forces me to pause or abandon the activity? (Thank you, by the way, for your sustained interest in ME/CFS.)
Click to expand...
No, that’s been disproven pretty comprehensively. What we know is that lactic acid tends to correlate with the burning feeling during exercise in healthy subjects but does not appear to be the cause (though it likely has a modifying effect on peripheral nerves mediating muscle fatigue more specifically)
 
Jonathan Edwards said:
I am not sure how that would relate to going above an anaerobic threshold - I don't see how lactate levels at rest would reflect that.
Click to expand...
I’m not so bothered about the anaerobic threshold. I’m interested in the correlation MECFS / PEM and lactate levels.

From that n=123 paper : 45% patients had lactate values around 2 mmol (or sometimes higher) at complete rest:
- “ resting conditions in hospital bed for at least 30  minutes and without preceding exercise “

Also, an important notion is the definition of rest IMO:
- What a healthy person or doctor might consider rest is actually not ‘rest’ for a severe / moderate / even mild ME patient
(I’m bedridden, was an athlete, but I’ve never 24/7 exercised as much as I do now).

What do you think explains these higher lactate levels at rest from that paper?
- I know it’s not the causation, but I’m looking for what explains the correlation (in about 45% of the patients)
 
Are we sure that in this hypothesis we accumulate lactic acid? Cannot it be something else?
I feel every day especially in my calfs something simillar to lactic acid but I think it's different what I felt after overexertion when I was healthy.
So I think lactic acid in a healthy person is different compare to "lactic acid" in ME/CFS.
Or is it a completly different thing? What do you think?
Also what is strange that after walking I feel this "lactic acid" only in my calfs and not in the upper legs. Do you have the same experiences?
 
“Lactic acid” and “lactate” are often used interchangeably, but physiologically they are not the same.
At normal body pH (~7.4), lactic acid (which has a pKa of ~3.9) is almost completely dissociated, meaning it exists as lactate (the negatively charged ion) plus a hydrogen ion (H⁺). As a result, free lactic acid essentially does not exist in the body under physiological conditions; what is actually produced and measured in blood and muscle is lactate.

The distinction matters because lactate itself is not the cause of muscle burning or acidosis.
Lactate is a normal, useful metabolic intermediate that can be shuttled to other tissues and oxidized for energy. The acidic effect comes from the accompanying hydrogen ions (H⁺) generated during rapid ATP turnover, not from lactate. Clinically and scientifically, blood tests measure lactate, even when reports loosely say “lactic acid,” and elevated lactate reflects altered metabolism or stress rather than the presence of an acid poisoning the tissues.
Click to expand...

tuha said:
I feel every day especially in my calfs something simillar to lactic acid but I think it's different what I felt after overexertion when I was healthy.
So I think lactic acid in a healthy person is different compare to "lactic acid" in ME/CFS.
Or is it a completly different thing? What do you think?
Click to expand...
You can only measure lactate in blood as far as I know, so that’s the data where we have to go from.

Apart from the publication, I posted, I know quite a few patients that tested high for lactate (many through self tested lactate meters /devices)
Also, the burning muscle is a common thing. I started to really suffer from it 10 years into my illness.

For me, it’s very similar to my healthy person experience, with the big difference is that it doesn’t go away and it’s way more intense.
 
Arfmeister said:
Also, the burning muscle is a common thing. I started to really suffer from it 10 years into my illness.

For me, it’s very similar to my healthy person experience, with the big difference is that it doesn’t go away and it’s way more intense.
Click to expand...
in my case those feelings are also constant, it doesnt go away even if I walk the same distance every day, it's nothing extreme and my muscles should be use to it.
What I cannot describe good is the feelings in my calfs. It doesnt hurt (only if I get muscle cramps which I can provoke easily by myself) like after overexertion when I was healthy. Also I wouldnt say that it's like burning muscle. I feel it like something very disagreable is accumulating in my calfs and I cannot get out of it. It's also disagreable when someone touch my calfs just a modest touch is disagreable.
 
Arfmeister said:
What do you think explains these higher lactate levels at rest from that paper?
- I know it’s not the causation, but I’m looking for what explains the correlation (in about 45% of the patients)
Click to expand...

It is a very peculiar study done retrospectively with PEM judged from old records. Moreover, the lactate levels all look fairly normal and mostly vary with food intake. I don't thin it means much.
 
I think people use 'lactic acid' as a lay term for lactate. When glucose is oxidised one of the hydrogen atoms becomes dissociable, so strictly speaking I think what is produced is lactic acid, but since the pH is clamped at 7.5 all we see is an increase in lactate ion (and probably some conversion of bicarbonate to CO2?).
 
You must log in or register to reply here.
Back
Top Bottom