The coronaviruses seemed to target people with extra pounds. Patients who were overweight or obese were more likely to die.
Scientists believe that the vulnerability of these patients is related to their weight.
The coronaviruses can cause a damaging defensive response in the body by attacking fat cells and certain immune cells.
The researcher said that the virus can cause harm to fat cells.
He said that whatever happens in fat doesn't stay in fat. It affects the neighboring tissues as well.
The research was posted online in October, but it has not yet been peer-reviewed or published. If the findings hold up, they may shed light on why certain younger adults with no other risks become ill, and why patients with excess pounds are vulnerable to the virus.
The authors of the study said the evidence could point to new Covid treatments that target body fat.
The virus hides in this place to evade our protective immune responses, according to Dr. Vishwa Deep Dixit, a professor of comparative medicine and immunology at Yale School of Medicine.
The United States has one of the highest rates of obese people in the world. 42 percent of American adults are obese. Black, Hispanic, Native American and Alaska Native people are more likely to be obese than other people in the U.S.
One of the report's two senior authors, Dr. Catherine Blish, said that this could be contributing to severe disease. The inflammation in the blood of the sick patients is the same as it is in the sick patients.
Body fat was thought of as a form of storage. Scientists now know that the tissue is biologically active, producing hormones and immune-system proteins that act on other cells, promoting a state of nagging low-grade inflammation even when there is no infection.
Inflammation is the body's response to an invader, and sometimes it can be so vigorous that it is more harmful than the infection that triggered it.
Fat tissue is made up of fat cells. Pre-adipocytes, which are fat cells, and a variety of immune cells are included.
Dr. Blish and his colleagues carried out experiments to see if fat tissue obtained from patients who had undergone bariatric surgery could be exposed to the coronaviruses.
The scientists found that the fat cells did not become very inflammatory. The immune cells called macrophages developed an inflammatory response if they were exposed.
The pre-adipocytes contributed to the inflammatory response. The scientists didn't look at whether particular variants were more destructive than others.
The research team obtained fat tissue from the bodies of European patients who had died of Covid and discovered the coronaviruses in fat near various organs.
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There are new Covid treatments. The pills for treating Covid-19 should be available soon. Scientists say we will need an arsenal of drugs to deploy against new variant if they erode the protection of existing vaccines.
The idea that a body of tissue can be used as a storehouse for disease is not new. H.I.V. and the flu are some of the Viruses that are found in body fat.
The body fat is unable to fight the coronaviruses due to its limited immune defenses. There can be a lot of body fat in obese people.
A man with an ideal weight but carrying a lot of fat is at risk of contracting a disease because the virus may "hang out" and cause a destructive immune system response.
Dr. Kass said that fat is the biggest organ in the body if you are very obese.
He said that the coronaviruses can reside there. It doesn't matter whether it hurts it, kills it or at best, it's a place to amplify itself. It becomes kind of a holding pattern.
The release of additional cytokines is triggered by the inflammatory response. He said it was like a perfect storm.
Dr. Blish and her colleagues speculated that body fat may contribute to long Covid, a condition that can cause fatigue for weeks or months after a recovery from an acute episode.
The data suggests that Covid vaccines and treatments may need to take into account the patient's weight and fat stores.
Barry Popkin, a professor of nutrition at the University of North Carolina at Chapel Hill, said that the paper is a wake-up call for the medical profession and public health to look more deeply into the issues of overweight and obese individuals.
Dr. Popkin said that they still aren't addressing the risk they have.
