New research suggests that COVID-19 infects fat cells, explaining why overweight and obese people have been at a higher risk of severe illness and death from the virus

The research study, led by the Stanford University School of Medicine, examined whether fat tissue obtained from patients of bariatric surgery could become infected with the virus that causes COVID-19, and tracked how various types of cells responded to the infection.

It found that fat cells and also immune cells (macrophages) can be infected, leading to a “robust inflammatory response”. The findings show the virus is able to evade the immune defenses within the body's fat cells, before causing inflammation elsewhere in the body and could help explain why patients with excess body weight are particularly vulnerable to the virus – and also why some younger adults with no underlying health issues become so ill.

The research will reinforce the importance of work being done in the health and fitness and spa and wellness industries, to help people control and reduce their percentage body fat.

THE DETAIL
In reporting the details of the findings, the researchers said: "Collectively, our findings indicate that adipose (fat) tissue supports SARS-CoV-2 infection and pathogenic inflammation and may explain the link between obesity and severe COVID-19.

"Obesity is clearly associated with adverse COVID-19 outcomes, but the underlying mechanism was unknown. We demonstrate that human fat tissue is 'permissive' to SARS-CoV-2 infection – the virus that causes COVID-19 – 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 pro-inflammatory phenotype. SARS-CoV-2 RNA is detectable in adipocytes in COVID-19 autopsy cases and is associated with an inflammatory infiltrate.

The research has not yet been peer-reviewed but has been published online here: www.hcmmag.com/fatcells