It’s a question everyone wants to answer: Who is more likely to develop long-term COVID-19, the debilitating symptoms that can last for weeks, months, or even longer, after an infection?
An unpublished new study by 23andMe is part of a growing body of research that sheds light on who experiences post-COVID conditions and why. The survey, which was voluntary and based on self-reported symptoms, had several important findings, including that women were much more likely to experience long-term symptoms, as were people with a previous diagnosis of depression or anxiety. More than half of those who reported a long diagnosis of COVID had a history of cardiometabolic disease, such as heart attacks or diabetes.
The 23andMe survey included 100,000 people who reported a diagnosis of COVID. Of these, 26,000 reported experiencing symptoms of COVID at least one month after becoming infected. In addition, more than 7,000 participants reported an official long-term diagnosis of COVID. Survey participants were asked about their symptoms at 3, 6, and 12 months. According to estimates by the Centers for Disease Control and Prevention, about 13.3% of people with COVID will experience symptoms for at least a month and 2.5% of people will experience symptoms for more than three months.
Dr. Stella Aslibekyan, a genetic epidemiologist at the San Francisco-based Consumer Genetics Company, told SFGATE that the 23andMe study is unique because it is so large and people are directly surveyed about it. symptoms. Many other long-term symptom studies are smaller and are based on data from medical records, as opposed to self-reported experiences.
“We are able to draw a more complete picture of the COVID experience than would be possible by just using medical records,” Aslibekyan said.
There are also limitations to this approach. Participation in the study was voluntary, as opposed to a random sample of patients from a healthcare system. Demographic characteristics and the characteristics of the people represented in this type of “self-selection” study are often skewed, depending on who has enough time and interest to complete the surveys.
The study, which has not been peer-reviewed or published in a medical journal, is part of an effort to solve the mystery of why so many people experience symptoms such as shortness of breath, cough, fever, fatigue, brain fog or chest pain. for weeks or months after a COVID infection. Many of these symptoms align with the symptoms of chronic fatigue syndrome, a misunderstood condition that has often been linked to other viral infections, such as the flu and Epstein-Barr.
“One hypothesis has long positioned COVID as an autoimmune condition, in which the immune system is attacking the body’s own tissues,” Aslibekyan said.
Many studies have found that long-term symptoms are much more likely to occur in more severe cases of COVID, but the U.S. Centers for Disease Control and Prevention says that “anyone who is infected with the virus can experience post-COVID conditions, even people who had mild or no symptoms of COVID-19 “.
“Researchers found that people with COVID who needed hospitalization were more than ten times more likely to be diagnosed with long-term COVID compared to those who were not hospitalized when controlling for age, sex, and ethnicity.” dir 23andMe.
Depression and anxiety also seem to be risk factors.
For Aslibekyan, one of the most illustrative findings of the survey was that people diagnosed with long-term COVID were twice as likely to report experiencing depression or anxiety before becoming infected.
There is extensive research on the relationship between depression and the immune system. People with diseases that cause an overactivation of the immune system are more likely to be diagnosed with depression, and vice versa.
“When [depressed people] are affected by this acute COVID-19 infection, these long-term symptoms also represent a malfunction of the immune system, so it makes sense that they are more vulnerable to these long-term immune system dysfunctions, ”Aslibekyan said.
Women are more likely than men to have long COVID
The researchers also found that people with two X chromosomes are more than twice as likely to be diagnosed with long-term COVID than men. This finding is consistent with other studies.
Aslibekyan said autoimmune conditions, such as multiple sclerosis and Sjogren’s syndrome, are also more common in women than men.
“The prevalence in women is really relevant to biology here, because the X chromosomes contain a lot of genes related to the immune system,” Aslibekyan said.
The double dose of these genes can drive stronger immune responses, whether they are disease-appropriate responses or uncontrolled inflammatory processes.
Brain fog was the most commonly reported symptom
The most frequently reported symptom of respondents was brain fog, a term for slow thinking, followed by fatigue, shortness of breath, and loss of smell. Among people who received long-term diagnoses of COVID, about 19% reported brain fog a year after infection.
Among participants who received vaccines after getting COVID, more than half (55%) reported no change in their symptoms, 25% reported an improvement in symptoms, and about 13% reported that his symptoms worsened. The rest did not know, were unsure or did not respond.
23andMe began collecting data in April 2020. This means that many of the people in the survey contracted COVID-19 before the vaccine became available.
“So what does that tell us?” said Aslibekyan. “The vaccine may not be a cure for long-term COVID. Now what we do know is that the vaccine is very good at preventing both the initial infection and the hospitalization, yes. a tenfold increase in the risk of long-term COVID. So the vaccine is ideal for prevention. “