[D66] Amsterdamse onderzoekers vinden oorzaak Post-Covid (Wuhan Coronavirus 2019-nCoV #994)

[Dr. Marc-Alexander Fluks]

Bron:  Amsterdam UMC
Datum: 4 januari 2024
URL:   
https://www.amsterdamumc.org/en/spotlight/tiredness-experienced-by-long-covid-patients-has-a-physical-cause.htm
Paper: https://www.nature.com/articles/s41467-023-44432-3
WebTV: 
https://npo.nl/start/serie/nos-journaal/seizoen-301/nos-journaal_91160/afspelen


Tiredness experienced by Long-COVID patients has a physical cause
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Researchers from Amsterdam UMC and Vrije Universiteit Amsterdam (VU) 
have discovered that the persistent fatigue in patients with long-COVID 
has a biological cause, namely mitochondria in muscle cells that produce 
less energy than in healthy patients. The results of the study were 
published today in Nature Communications.

'We're seeing clear changes in the muscles in these patients,' says 
Michele van Vugt, Professor of Internal Medicine at Amsterdam UMC.

25 long-COVID patients and 21 healthy control participants participated 
in the study. They were asked to cycle for fifteen minutes. This cycling 
test caused a long-term worsening of symptoms in people with long-COVID, 
called post-exertional malaise (PEM). Extreme fatigue occurs after 
physical, cognitive, or emotional exertion beyond an unknown, individual 
threshold. The researchers looked at the blood and muscle tissue 1 week 
before the cycling test and 1 day after the test.

'We saw various abnormalities in the muscle tissue of the patients. At 
the cellular level, we saw that the mitochondria of the muscle, also 
known as the energy factories of the cell, function less well and that 
they produce less energy,' says Rob Wust, Assistant Professor at 
Department of Human Movement Sciences at the VU University. 'So, the 
cause of the fatigue is really biological. The brain needs energy to 
think. Muscles need energy to move. This discovery means we can now 
start to research an appropriate treatment for those with long-COVID,' 
adds van Vugt.

One of the theories about long-COVID is that coronavirus particles may 
remain in the body of people who have had the coronavirus. 'We don't see 
any indications of this in the muscles at the moment,' says Van Vugt. 
The researchers also saw that the heart and lungs functioned well in the 
patients. This means that the long-lasting effect on patient's fitness 
is not caused by abnormalities in the heart or lungs.


Exercising within your own limits

Exercising is not always good for patients with long-COVID. 'In concrete 
terms, we advise these patients to guard their physical limits and not 
to exceed them. Think of light exertion that does not lead to worsening 
of the complaints. Walking is good, or riding an electric bike, to 
maintain some physical condition. Keep in mind that every patient has a 
different limit,' says Brent Appelman, researcher at Amsterdam UMC. 
'Because symptoms can worsen after physical exertion, some classic forms 
of rehabilitation and physiotherapy are counterproductive for the 
recovery of these patients,' van Vugt adds.


Long-COVID symptoms

Although the majority of people infected with the SARS-CoV-2 virus 
recover within weeks, a subgroup, estimated to be around one in eight, 
will get long-COVID. Symptoms in patients with long-COVID, post-acute 
sequelae or COVID or post-COVID syndrome (PCS) include severe cognitive 
problems (brain fog), fatigue, exercise intolerance, autonomic 
dysregulation, postural orthostatic tachycardia syndrome (POTS), 
orthostatic intolerance, and worsening of symptoms after PEM.

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