New long Covid study: How changes in muscle structure tire you out during exercise

The study shows that long Covid can follow even a mild bout of the infection, says Dr Rajeev Jayadevan, Co-Chairman, IMA Covid-19 task force

Are you one of those who cannot exercise quite as well as you did before you had Covid and get exhausted or short of breath too soon? Now researchers have found what’s causing this post-exercise malaise among people with long Covid although they weren’t hospitalised during the infection and had fairly active lives before it. A study by Amsterdam University Medical Center, published in Nature Communications journal on January 4, has found that muscle structure and function were altered among people with long-term Covid compared to other healthy people.

What’s new about the finding?

When the researchers analysed the biopsies taken before and after exercise, they found that those with long Covid had more white fibres in their muscles than regular people. “These fibres had fewer mitochondria within their cells, which are a powerhouse responsible for our energy levels, and fewer capillaries. So the exhaustion is a result of  inefficient energy extraction from cells during exercise. This is like using an old mobile phone with a weak battery on a low charge. With even minimal use, the phone shuts down. This doesn’t happen with a new phone. Poor mitochondria functions are like power failure,” explains Dr Rajeev Jayadevan, Co-Chairman, Indian Medical Association Covid-19 task force (national).

Importantly, the study did not find specific deficits in oxygen supply as feared earlier, he says. The team also found that people with long Covid had more clumps of a protein called amyloid in their skeletal muscles, although there was no evidence that these “microclots” blocked blood vessels as some researchers had thought previously.

Why is this study important considering new Covid variants are emerging

This virus has shown that it can evolve faster than man can make vaccines. “This trend will likely continue, which means that the human race will likely have lower immunity against new infections, even though vaccination and prior infections protect us from severe outcomes. The study also shows that long Covid can follow even a mild bout of the infection,” says Dr Jayadevan.

How many in India suffer from long Covid?

Most studies have reported percentages ranging from 9 per cent to 37 per cent. Even if we take a conservative estimate of five per cent, the impact on the population as a result of this condition will be huge. A study from Kerala had reported that 62 per cent people with long Covid found it difficult to get back to work even after ten months. “Unfortunately, many of these patients suffer silently at home and even if they go to a local doctor’s clinic, they will be sent home saying their routine investigations are all normal. They are not counted in a centralised database,” says Dr Jayadevan.

Can long Covid be resolved?

Unfortunately, there is no specific remedy apart from supportive care and medical therapy addressing certain sub-groups with this condition, he adds. And till then, you can tweak your physical activity to more acceptable levels of intensity.

 

https://indianexpress.com/article/health-wellness/new-long-covid-study-changes-in-muscle-structure-9097788/