COVID infection in fat cells (adipose tissue) accounts at least in part for the association between severe COVID outcomes (death) and obesity; this is a complex relationship in the pathogenesis

by Paul Alexander

This must be studied not only for the severe sequelae in COVID in morbid obesity and heavy body weight but for the relationship with other pathologies; COVID helped flesh out unhealthy societies

COVID-19 showed us just how unhealthy the US, Canada, UK, Australia and other nations are. It functions to exploit our risk factors. For example, if there was a closed island of 10,000 people, with a mean age of 40 years and standard deviation of 10 years so the oldest will be about 60 and the youngest about 20 with a few children and a few older persons but everyone is healthy, proper vitamin D serum levels (50 ng/mL), no obesity or excess body weight, no illnesses or underlying medical conditions or immunosuppression or immunocompromised, then COVID will not get anyone sick or no one will die from it. It will infect a few and run its course and thats it. Children’s and young persons’ innate immunity will vanquish it with ease and if there is breakthrough, then natural acquired immunity will mop it up and there will be long-lived immunity. NO need for any vaccine!

COVID-19 emerged as an illness of economic circumstances and has impacted poorer persons with a greater force of morbidity and mortality. Obesity is a condition not of affluence though it resides there, but also of lower economic circumstances. It is a complex situation but one that has to be addressed and I have argued in DC and openly and in writing that the US Task Force under Fauci et al. and the Surgeon Generals (Trump and Biden, Adams and Murthy) have failed and squandered an opportunity to use their pulpits to educate the public and impart needed public health information. Especially to the African American population and minority populations where obesity has hit very hard. This is not a blame or insult issue. This is one to help and inform. It is as if public health e.g. CDC and Fauci et al. do not have any care or concern for the impoverished in our societies. They are invisible and Fauci wasted near 2 years with largely often inaccurate and misleading information that still today cannot be backed up by any science.

Prior research raised the alarming link between adipose tissue accumulation (expression) of ACE 2 receptors that the virus uses to gain access to the metabolic machinery of the host cells. Al-Benna examined the association of high-level gene expression of ACE 2 in adipose tissue with subsequent mortality of COVID-19 infection in obese patients. They investigated ACE2 gene expression in adipose tissue and lung tissue using a public database. “ACE2 gene expression was present in both visceral and subcutaneous adipose tissues. The gene expression profile demonstrated that ACE 2 gene expression was higher in human visceral and subcutaneous adipose tissues than human lung tissue.”

Similarly, Korakas et al. reported on endothelial dysfunction and arterial stiffness that may favor the recently discovered infection of the endothelium by SARS-CoV-2, “whereas alterations in cardiac structure and function and the prothrombotic microenvironment in obesity could provide a link for the increased cardiovascular events in these patients.” Petrakis et al. also reported on obesity as a risk factor for increased COVID‑19 prevalence, severity and lethality, reviewing the expanding body of evidence that links obesity with COVID‑19 and a number of mechanisms from “immune system activity attenuation to chronic inflammation are implicated. Lipid peroxidation creates reactive lipid aldehydes which in a patient with metabolic disorder and COVID‑19 will affect its prognosis. Finally, pregnancy‑associated obesity needs to be studied further in connection to COVID‑19 as this infection could pose high risk both to pregnant women and the fetus.” Pasquarelli-do-Nascimento et al. reviewed how obesity is linked to a pro-inflammatory and metabolic dysregulation as well as increased SARS-CoV-2 host cell entry in adipose tissue and initiation of hyper-coagulopathy, “leading people with obesity to develop severe forms of COVID-19 and also death.” 

A very recent non-peer reviewed publication warranting consideration and which is the focus of this current op-ed, is authored by Martínez-Colón et al. and looks at the issue of SARS-CoV-2 infecting human adipose tissue and the eliciting of an inflammatory response consistent with severe COVID-19. Researchers report 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…that SARS-CoV-2 RNA is detectable in adipocytes in COVID-19 autopsy cases and is associated with an inflammatory infiltrate.” The findings suggest that adipose (fat) tissue supports SARS-CoV-2 infection and “pathogenic inflammation and may explain the link between obesity and severe COVID-19.”

I share this as a means to communicate research evidence to hopefully motivate the public health leaders (to not waste their opportunity) to properly message the public on the impact of obesity as well as the positive beneficial role of vitamin D (25-hydroxy-vitamin D) sunlight and supplements in optimal immune system function, in SARS-2 and other infections/illnesses.