COVID-19 can make some people’s muscles balloon in size

By Mark Waghorn via SWNS

COVID-19 can make muscles balloon in size, according to new research.

They grow in some patients - by almost two-thirds, say scientists.

It's believed the immune response damages mitochondria, the power stations of cells, leading to a loss of energy fuels which builds up water - causing muscles to swell.

The phenomenon stunned the Belgian team, as muscle shrinkage is a common complication among critically ill sufferers.

Biopsies from 18 individuals showed the muscles of four had increased "massively" however this was not the case for all.

Type I and type 11 fibres had swollen by 62 and 32 percent. They support endurance activities and quick powerful movements, respectively.

Lead author Dr. Toon Mostien, of the Jessa Hospital, Hasselt, said: "This type of swelling can lead to muscle fibres dying.

"It is likely the increase in muscle fibre size was only temporary."

Overall, type I fibres grew by six percent and type 2 shrank by five percent - results that were statistically insignificant.

But if those who bucked the trend were excluded from the calculations, the remaining patients showed significant muscle wastage.

Dr. Mostein said: "Type I fibres shrank by eleven percent and type 2 by 17 percent."

Tissue from the thigh muscle vastus lateralis was collected up to three days before and five to eight days after admission.

It is the largest and most powerful muscle in the thigh.

The average age of the participants was 69 and the majority were men.

Samples were scanned under the microscope for any changes that had occurred during the first week in intensive care.

Bed rest and mechanical ventilation often leads to muscle wastage.

It can hamper recovery and affect mobility and quality of life.

Previous research has shown fibres reduce by almost a fifth after a week in ICU. It is feared COVID-19 causes even greater damage.

The researchers found the number of capillaries supplying type I and II fibres with oxygen and nutrients fell by five and ten percent, respectively.

Dr. Mostien said: "Although the results were not significant, a drop in perfusion of 10 percent could potentially contribute to muscle fibre destruction."

He explained: "There are concerns that immune response to COVID-19 can exacerbate muscle wastage.

"It means critically ill COVID-19 patients experience more severe muscle damage than the general ICU population.

"Given the global burden of COVID-19 it is vital we learn more about this. Our research is an important first step."

The study was presented at Euroanaesthesia, a virtual meeting of the European Society of Anaesthesiology and Intensive Care.