Hypothesis: inflammatory acid-base disruption underpins Long Covid 2023, van der Togt & Rossman

[SNT Gatchaman]

What I suspect is that lactic acidosis can occur too easily (as a downstream effect of compromised metabolism) and this may be part of the rapid fatiguability we experience. One question I had was whether the degree of fatiguability had any relationship to progression to PEM — i.e. can we tolerate pushing our barely adequate 'rescue' metabolism up to a point but go too far and the result is PEM? If so, could that have any relationship to measurable lactate levels and potentially be predicted and avoided?

I hope this might have been well evaluated by NIH and so we might get a proper answer. Reading Brian's descriptions of what the heroic patients put themselves through I think much valuable data will have been obtained.

 

[Mij]

I've had my RBC lactate values measured during next day delayed PEM and my results were normal. I felt horrible both cognitively and physically during the blood draw.

 

[Trish]

Members only thread for sharing lacate results and discussion
The Acid Test - Lactate self testing

 

[Paulie]

One thing I'm not sure about is the difference between lactate in peripheral blood from fingerpricks and lactate as measured by a catheter as per that study I linked to above. Is there any reason that the different sources/methods might tell a different story?

There is that one 2022 study which seemed to suggest higher lactate during exercise. I'm sure that there have been more studies on this, but I can't recall them, and haven't checked them out. Is there a body of evidence suggesting people with ME/CFS have higher lactate levels with exercise than matched healthy controls?

That's an interesting thought about levels possibly being different upon waking - I don't think I did tests upon waking. I assume that you haven't found anything unusual there with your lactate meter @SNT Gatchaman?

Not sure if this answers your question but I noticed in the manual of the lactate device I bought that it says either venous or capillary blood can be used on the test strips.

 

[Paulie]

The device I bought (Glucorx x6) includes claims about accuracy in the leaflet that comes with test strips, including differences in accuracy between venous and capillary tests. See image.

 

[darrellpf]

I did a two day exercise test at a facility that usually tests athletes. When I asked if there was anything unusual in the tests the lady said that the amount of lactate I was producing was more like a young person than someone 56 years old.

 

[Hutan]

When I asked if there was anything unusual in the tests the lady said that the amount of lactate I was producing was more like a young person than someone 56 years old.

So, a relatively low level?

Lactate testing for sports applications

During high intensity exercise, increasing glucose metabolism to fuel muscle activity is oxygen dependent and the switch to anaerobic glucose metabolism with lactate production as the endpoint has downstream consequences. Muscles also have a finite capacity to utilise lactate and remove lactate from the muscle fibre. Lactate therefore begins to accumulate in the muscle fibres and eventually in the bloodstream.

With training, the body is able to increase its utilisation of lactate and thus maintain muscle function for longer periods before lactate starts to accumulate in the muscles and subsequently becomes elevated in the blood.

Increased endurance is therefore associated with an increased lactate threshold. Thus the lactate threshold definition is the first increase in blood lactate above the resting level, which is typically between 1 and 2 mM in healthy subjects.

That quote above suggests that lactate levels in ME/CFS might be the result of a mix of factors. People who are sedentary, so physically untrained, might have a low lactate threshold, and so blood levels of lactate might increase quickly. And/or, having ME/CFS might "train" the body to utilise lactate more effectively, if aerobic respiration isn't working well, keeping lactate levels low. It's also possible that there is something specifically about the ME/CFS metabolism that produces unusual lactate outcomes, but I don't think we've even identified what those unusual lactate outcomes are.

I am rather doubtful that lactate levels are very informative in ME/CFS. That said, there are other conditions that can cause some ME/CFS-like symptoms and high lactate levels, including some that need swift medical attention, so testing is not a bad idea.

 

[Paulie]

I did a two day exercise test at a facility that usually tests athletes. When I asked if there was anything unusual in the tests the lady said that the amount of lactate I was producing was more like a young person than someone 56 years old.

That's interesting if your lactate was low after exercise because a couple of days ago I tested with my lactate machine and after walking 2 miles and resting an hour the two tests were almost identical. I was only walking but to me it felt like I had been running - I collapsed on the bed after doing the first test - exhausted and legs burning. But no apparent increase in lactate. I would have expected at least 3 or 4 mmol/L and then a reduction for the second test.