WASHINGTON: Regular exercise may reduce the risk of acute respiratory distress syndrome, a major cause of death in patients infected with the novel coronavirus that causes COVID-19, according to a review of studies.
Researchers from University of Virginia in the US suggest regular exercise may be a potential treatment approach for acute respiratory distress syndrome (ARDS).
The study review, published in the journal Redox Biology, shows that there is strong support for the possibility that exercise can prevent or at least reduce the severity of ARDS, which affects between 3 per cent and 17 per cent of all patients with COVID-19.
The US Centers for Disease Control and Prevention estimates 20 to 42 per cent of patients hospitalised for COVID-19 will develop ARDS, the researchers said.
The range for patients admitted to intensive care is estimated at 67 to 85 per cent, they said.
Research conducted prior to the pandemic suggested that about 45 per cent of patients who develop severe ARDS will die, the researchers said.
"All you hear now is either social distancing or ventilator, as if all we can do is either avoiding exposure or relying on a ventilator to survive if we get infected," said Zhen Yan of the University of Virginia School of Medicine.
"The flip side of the story is that approximately 80 per cent of confirmed COVID-19 patients have mild symptoms with no need of respiratory support.
"Our findings about an endogenous antioxidant enzyme provide important clues and have intrigued us to develop a novel therapeutic for ARDS caused by COVID-19," said Yan.
Yan compiled the review of existing medical research, including his own, looking at an antioxidant known as "extracellular superoxide dismutase" (EcSOD).
This potent antioxidant, he explained, hunts down harmful free radicals, protecting our tissues and helping to prevent disease.
Our muscles naturally make EcSOD, secreting it into the circulation to allow binding to other vital organs, but its production is enhanced by cardiovascular exercise, said Yan.
A decrease in the antioxidant is seen in several diseases, including acute lung disease, ischemic heart disease and kidney failure, Yan's review shows.
Lab research in mice suggests that blocking its production worsens heart problems, while increasing it has a beneficial effect, he said.
Research suggests that even a single session of exercise increases production of the antioxidant, prompting Yan to urge people to find ways to exercise even while maintaining social distancing.
"We cannot live in isolation forever.
Regular exercise has far more health benefits than we know.
The protection against this severe respiratory disease condition is just one of the many examples," he said.
Yan's review also suggests EcSOD as a potential treatment for ARDS and many other health conditions.
Gene therapy, for example, might one day be used to increase production of the antioxidant so that its protective presence in the lungs is enhanced in patients battling COVID-19, he said.