Researchers Have Identified 4 Health Factors That May Explain Why Some People Get Long COVID
Getty A sick woman
Researchers are finally getting a sense of why some people develop long COVID in one of the first studies to investigate the difficult illness.
Long COVID has been one of the mysteries of COVID-19 since it emerged two years ago, with some people dealing with symptoms like brain fog, fatigue and loss of taste or smell that linger well beyond their initial illness.
Why some patients are stuck with long COVID while others fully recover has been a complicated question, but a new study, published Tuesday in the journal Cell, points to four factors that researchers found were associated with long COVID.
The researchers followed more than 200 COVID-19 patients for two to three months after their diagnosis and found that regardless of if they had mild or severe cases, they were more likely to have four commonalities. One was a high level of coronavirus RNA in their blood early on in their illness, indicating a high viral load. Another was a history of Epstein-Barr virus, which many people can have at a younger age (typically as mononucleosis) and then lives on in the body.
A third factor was having autoantibodies — those found in autoimmune disorders — which mistakenly attack the immune system. And the last factor was type 2 diabetes, though the researchers said that in further studies with more patients it may just be that diabetes is one of many conditions that can lead to long COVID.
"I think this research stresses the importance of doing measurements early in the disease course to figure out how to treat patients, even if we don't really know how we're going to use all that information yet," Jim Heath, the lead investigator of the study and president of the Institute for Systems Biology, told The New York Times. "Once you can measure something, then you may be able to start doing something about it."
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The researchers surveyed the patients on their symptoms, and found that 37% of patients had three or more symptoms of long COVID in the two or three months after their initial infection. Another 24% had one or two long COVID symptoms, and 39% had no lingering symptoms.
Of the group with three or more long COVID symptoms, 95% had one of the four factors that are associated with the illness, with most — two-thirds of patients — having autoantibodies. The other three factors appeared in the other third of patients, and some patients had more than one of the factors.
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There were also findings from the study that the researchers want to dig into, one being that people who continued to have trouble breathing had lower levels of cortisol, the hormone that regulates stress. Health said that some doctors are already trying cortisol replacement therapy with their patients.
"We did this analysis because we know patients will go to physicians and they'll say that they're tired all the time or whatever, and the physician just tells them to get more sleep. That's not very helpful. So, we wanted to actually have a way to quantify and say that there's actually something wrong with these patients," Heath said.
