Researchers from the Amsterdam University Medical Center (UMC) and the Free University of Amsterdam (VU) have discovered that the fatigue experienced by people with persistent covid has a biological cause: the mitochondria of their muscle cells produce less energy than in healthy people.
“We observed clear changes in the muscles of these patients; At the cellular level we saw that the muscle mitochondria, also known as the energy factories of the cell, function worse and produce less energy,” explained Rob Wüst, associate professor in the Department of Human Movement Sciences at VU, when presenting the results. of the study, which were published Thursday in Nature Communications.
The study involved 25 people with persistent Covid and 21 healthy people, who had to pedal for 15 minutes, an effort that caused a long-term worsening of symptoms in the members of the first group. The researchers analyzed the blood and muscle tissue of the participants a week before and one day after taking the bicycle test.
Although one of the theories about persistent covid is that virus particles remain in the person’s body, researchers say they have not seen any signs of this in the muscles, nor have they detected alterations in the functioning of the heart or muscles. lungs, so they consider that the prolonged fatigue of those affected is not due to anomalies in these organs.
The cause, according to the authors of the study, is in the malfunction of the cell’s energy factories, because the brain needs energy to think and the muscles need energy to move. “This discovery means that we can now begin to investigate an appropriate treatment” for those affected, said Michèle van Vugt, a specialist in Internal Medicine at the UMC in Amsterdam.
While this is achieved, and given that the symptoms worsen with effort, the authors of the study believe that it must be kept in mind that physical exercise or some forms of physiotherapy are not always good, and can even be counterproductive, for people with covid persistent. Brent Appelman, a researcher at the UMC, urges those affected to perform light efforts, such as walking or riding an electric bicycle, to maintain a certain physical condition but without worsening their discomfort.