According to a study, visceral fat, or the fat around the liver, intestines, and other organs, contributes more to severe COVID-19 than subcutaneous fat, or the fat beneath the skin, as in "love handles." Visceral fat is typically regarded as a risk factor for cardiovascular disease, diabetes, and high blood pressure. The study is published in Nature Communications.

Experts infected two types of adipocytes (fat cells) in the lab: one was made from human stem cells extracted from the subcutaneous tissue, while the other was developed from stem cells acquired from visceral fatty tissue.

The study revealed that SARS-CoV-2 could infect visceral adipocytes more easily. Comparing this type of fat cell to subcutaneous adipocytes, the viral load rose significantly. Researchers believed this was mostly caused by greater concentrations of the protein ACE-2, with which the virus interacts to penetrate cells present on the cell surface. These tissues produced more pro-inflammatory cytokines as a result of the immune system being put on alert due to the presence of a threat when visceral adipocytes, or the tissues where fat is stored as an energy source, were infected.

The study model further hypothesized that the virus could multiply more readily in obese people with greater visceral adipose tissue, intensifying the inflammatory response. On the other hand, the team noticed a decline in lipolysis in subcutaneous adipocytes. Lipolysis is the process by which fats and other lipids are broken down into fatty acids for energy during physical activity or fasting periods. 

Different SARS-CoV-2 strains were introduced to visceral adipocytes and compared with subcutaneous adipocytes. The difference in susceptibility was seen only in the response to the ancestral virus.

(Source: https://www.financialexpress.com/lifestyle/health/fat-around-organs-more-susceptible-to-severe-covid-19-than-fat-under-skin-says-study/2904524/)