From the start of the pandemic, the coronavirus seemed to target people carrying extra pounds. Patients who were overweight or obese were more likely to develop severe Covid-19 and more likely to die.

Though these patients often have health conditions like diabetes that compound their risk, scientists have become increasingly convinced that their vulnerability has something to do with obesity itself.

Now researchers have found that the coronavirus infects both fat cells and certain immune cells within body fat, prompting a damaging defensive response in the body.

“The bottom line is, ‘Oh my god, indeed, the virus can infect fat cells directly,’” said Dr. Philipp Scherer, a scientist who studies fat cells at UT Southwestern Medical Center in Dallas, who was not involved in the research.

“Whatever happens in fat doesn’t stay in fat,” he added. “It affects the neighboring tissues as well.”

The research has not yet been peer-reviewed or published in a scientific journal, but it was posted online in October. If the findings hold up, they may shed light not just on why patients with excess pounds are vulnerable to the virus, but also on why certain younger adults with no other risks become so ill.

The study’s authors suggested the evidence could point to new Covid treatments that target body fat.

“Maybe that’s the Achilles’ heel that the virus utilizes to evade our protective immune responses — by hiding in this place,” Dr. Vishwa Deep Dixit, a professor of comparative medicine and immunology at Yale School of Medicine, said.

The finding is particularly relevant to the United States, which has one of the highest rates of obesity in the world. Most American adults are overweight, and 42 percent have obesity. Black, Hispanic, Native American and Alaska Native people in the U.S. have higher obesity rates than white adults and Asian Americans; they have also been disproportionately affected by the pandemic, with death rates roughly double those of white Americans.

“This could well be contributing to severe disease,” Dr. Catherine Blish, a professor at Stanford University Medical Center and one of the report’s two senior authors, said. “We’re seeing the same inflammatory cytokines that I see in the blood of the really sick patients being produced in response to infection of those tissues.”

Body fat used to be thought of as inert, a form of storage. But 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 composed mostly of fat cells, or adipocytes. It also contains pre-adipocytes, which mature into fat cells, and a variety of immune cells, including a type called adipose tissue macrophages.

Dr. Blish, with colleagues at Stanford and in Germany and Switzerland, carried out experiments to see if fat tissue obtained from bariatric surgery patients could become infected with the coronavirus, and tracked how various types of cells responded.

The fat cells themselves could become infected, the scientists found, yet did not become very inflamed. But certain immune cells called macrophages also could be infected, and they developed a robust inflammatory response.

Even stranger, the pre-adipocytes were not infected, but contributed to the inflammatory response. (The scientists did not examine whether particular variants were more destructive in this regard than others.)

The research team also obtained fat tissue from the bodies of European patients who had died of Covid and discovered the coronavirus in fat near various organs.

The idea that adipose tissue might serve as a reservoir for pathogens is not new, Dr. Dixit said. Body fat is known to harbor a number of them, including H.I.V. and the influenza virus.

The coronavirus appears to be able to evade the body fat’s immune defenses, which are limited and incapable of fighting it effectively. And in people who are obese, there can be a lot of body fat.

A man whose ideal weight is 170 pounds but who weighs 250 pounds is carrying a substantial amount of fat in which the virus may “hang out,” replicate and trigger a destructive immune system response, said Dr. David Kass, a professor of cardiology at Johns Hopkins.

“If you really are very obese, fat is the biggest single organ in your body,” Dr. Kass said.

The coronavirus “can infect that tissue and actually reside there,” he said. “Whether it hurts it, kills it or at best, it’s a place to amplify itself — it doesn’t matter. It becomes kind of a reservoir.”

As the inflammatory response snowballs, cytokines trigger even more inflammation and the release of additional cytokines. “It’s like a perfect storm,” he said.

Dr. Blish and her colleagues speculated that infected body fat may even contribute to “long Covid,” a condition describing troublesome symptoms like fatigue that persist for weeks or months after recovery from an acute episode.

The data also suggest that Covid vaccines and treatments may need to take into account the patient’s weight and fat stores.

“This paper is another wake-up call for the medical profession and public health to look more deeply into the issues of overweight and obese individuals, and the treatments and vaccines we’re giving them,” said Barry Popkin, a professor of nutrition at University of North Carolina at Chapel Hill, who has studied the heightened risk that Covid poses to those with obesity.

“We keep documenting the risk they have, but we still aren’t addressing it,” Dr. Popkin said.

https://www.msn.com/en-us/news/us/the-coronavirus-attacks-fat-tissue-scientists-find/ar-AARCqfv?ocid=msedgntp - https://www.msn.com/en-us/news/us/the-coronavirus-attacks-fat-tissue-scientists-find/ar-AARCqfv?ocid=msedgntp

The COVID-19 pandemic, caused by the viral pathogen SARS-CoV-2, has taken the lives of millions of individuals around the world. Obesity is associated with adverse COVID-19 outcomes, but the underlying mechanism is unknown. In this report, we demonstrate that human adipose tissue from multiple depots is permissive to SARS-CoV-2 infection and that infection elicits an inflammatory response, including the secretion of known inflammatory mediators of severe COVID-19. We identify two cellular targets of SARS-CoV-2 infection in adipose tissue: mature adipocytes and adipose tissue macrophages. Adipose tissue macrophage infection is largely restricted to a highly inflammatory subpopulation of macrophages, present at baseline, that is further activated in response to SARS-CoV-2 infection. Preadipocytes, while not infected, adopt a proinflammatory phenotype. We further demonstrate that SARS-CoV-2 RNA is detectable in adipocytes in COVID-19 autopsy cases and is associated with an inflammatory infiltrate. Collectively, our findings indicate that adipose tissue supports SARS-CoV-2 infection and pathogenic inflammation and may explain the link between obesity and severe COVID-19.

https://www.biorxiv.org/content/10.1101/2021.10.24.465626v1 - https://www.biorxiv.org/content/10.1101/2021.10.24.465626v1

CDC study finds about 78% of people hospitalized for Covid were overweight or obese

About 78% of people who have been hospitalized, needed a ventilator or died from Covid-19 have been overweight or obese, the Centers for Disease Control and Prevention said in a new study Monday.

https://www.cnbc.com/2021/03/08/covid-cdc-study-finds-roughly-78percent-of-people-hospitalized-were-overweight-or-obese.html - https://www.cnbc.com/2021/03/08/covid-cdc-study-finds-roughly-78percent-of-people-hospitalized-were-overweight-or-obese.html

Now's a good time to start that diet if you are afraid of getting covid and having a severe outcome. I'd be willing to bet those breakthrough cases with severe and negative covid outcomes are almost exclusively among those overweight or obese.

It's not what it appears....

74% of US population is considered overweight

I'd look at the obese numbers to get a truer picture...

ksc wrote: It's not what it appears.... 74% of US population is considered overweight I'd look at the obese numbers to get a truer picture...

Among 148,494 adults who received a Covid-19 diagnosis during an emergency department or inpatient visit at 238 U.S. hospitals from March to December, 71,491 were hospitalized. Of those who were admitted, 27.8% were overweight and 50.2% were obese, according to the CDC report.

Certainly my cousin found that on his Covid ward, the other 5 occupants were huge. 

I wonder if this would also account for why younger people on the whole tend to have a better outcome than the old. We know that sarcopenia (the loss of muscle mass) starts in our 30s and so the older you get, the less muscle you have unless you are actively exercising to build muscle, and so this bulk is replaced by fat. 

This info also supports what we're seeing here in NZ which is that the populations being hit hardest by Covid are the Maori and the Pasifika people, who are often very large people. I've been told that practically all the hospitalized cases of Covid here have been Pasifika. The government has been called out for shaming them in it's early Covid statements and so have now stopped commenting on race but I heard this from a medical friend recently.

Americans gained nearly 2 pounds per month under COVID-19 shelter-in-place orders in 2020, according to a new study published Monday in JAMA Network Open.

Those who kept the same lockdown habits could have gained 20 pounds during the past year, the study authors said.

https://www.webmd.com/lung/news/20210323/lockdown-weight-gain-study - https://www.webmd.com/lung/news/20210323/lockdown-weight-gain-study

Appears lock downs were a bad thing in a couple different ways. Adding pounds didn't help the situation according to the study linking fat to severe outcomes.

In test tube fat kills  lymphocytes pretty quickly.  When isolating out  lymphocytes from lymph nodes taken from  patients post op there can be no fat contamination as you will just retrieve dead lymphocytes which are useless.

Hz x

Seriously do you ever really process what you researched?!?I have better things to do then to pokeholes all through these supposedly scientific studies.  If any of this is true why was COVID  such a huge killer of thin Asian populations???Why is Japan so successful at prevention and lack of high death toll.  Oh maybe it is because they aare so  thin.  No they gave out free Ivermectin!!!

[url]https://www.healthline.com/health/types-of-body-fat#essential-fat[/url] or https://www.healthline.com/health/types-of-body-fat#essential-fat - https://www.healthline.com/health/types-of-body-fat#essential-fat ;

Essential fat is exactly that — essential for your life and a healthy body. This fat is found in your:

• brain
• bone marrow
• nerves
• membranes that protect your organs

Essential fat plays a major role in hormone regulation, including the hormones that control fertility, vitamin absorption, and temperature regulation.

According to the  https://www.acefitness.org/education-and-resources/lifestyle/tools-calculators/percent-body-fat-calculator" rel="noopener noreferrer" style="-webkit-font-smoothing: antialiased; box-sizing: inherit; background-color: transparent; cursor: pointer; text-decoration: none; border-color: currentcolor; color: rgb(2, 131, 141); - American Council on Exercise , women need at least 10 to 13 percent of their body composition to come from essential fat to be in good health, while men require at least 2 to 5 percent.

DJ Also Asian people do have fat. Obesity is a growing problem in richer parts of Asia...But even slim people will have and need body fat. The article above is mixing two stories...

-Fat cells as entry for viral infection

-Overweight may see more severe infection (because they have more [url]https://www.healthline.com/health/types-of-body-fat[/url] or https://www.healthline.com/health/types-of-body-fat - https://www.healthline.com/health/types-of-body-fat of the wrong types of fat). 

DJ-Infection can be spread by any cell....fat cells may cause more immune overreaction...(at least that is what I make of it...) 

This post reminded me of a TV show that aired over here a couple of years ago. It was a British show and the presenter was Angela Ripon, she is slim and looks fit and they did this complicated test on her to check her body fat, and the results surprised her because they found that she had 7 litres of hard fat packed in her abdomen around her vital organs. Now she's in her 70s and probably not as active as she once was, but it was surprising to see just how much fat she was packing and the doctor said it was a dangerous type of fat to have. They talked about the concept of fat skinny, and i guess that there are many visibly slim people out there who are carrying just as much fat in the wrong places.