Covid-19: Fat, Obesity, Inflammation, Ethnicity, and Sex Differences.

Indrikis A Krams,Tatjana Krama,Markus J Rantala,Severi Luoto,Priit Jõers

doi:10.3390/pathogens9110887

Abstract

Although obesity is known to be a risk factor for COVID-19 severity, there is an urgent need to distinguish between different kinds of fat—visceral and subcutaneous fat—and their inflammation status in COVID-19. These different fat types have partially diverging biochemical roles in the human body, and they are differentially associated with SARS-CoV-2, which targets the angiotensin-converting enzyme 2 (ACE2) for cell entry. ACE2 is highly expressed in adipose tissue, especially in visceral fat, suggesting an important role for this tissue in determining COVID-19 disease severity. In this perspective article, we discuss group differences in the amount of visceral fat levels and the extent of inflammation in adipocytes of visceral fat tissue, which may, in part, drive population, cross-national, ethnic, and sex differences in COVID-19 disease. It is vital to steer the scientific community’s attention to the effects of visceral fat in creating individual and population differences in COVID-19 severity. This can help researchers unravel the reasons for the reported population, ethnic, and sex differences in COVID-19 severity and mortality.

Highlights

At the end of 2019, the city of Wuhan in China became the epicenter of the coronavirus pandemic.It appeared initially as an outbreak of atypical pneumonia
This much-discussed dual role of angiotensin-converting enzyme 2 (ACE2) in COVID-19 might cause the variability in susceptibility to SARS-CoV-2 in different populations and sexes depending on the amount of their subcutaneous and visceral fat, adipocyte hypertrophy, and the inflammation level of their adipose tissue
Virologists, and physiologists should collect data on the severity of COVID-19 in connection with data on the amount and condition of visceral and subcutaneous adiposity of people infected with the SARS-CoV-2 coronavirus [21,22,23]

Summary

Introduction

At the end of 2019, the city of Wuhan in China became the epicenter of the coronavirus pandemic. While a high amount of adipose tissue is a risk factor in some viral diseases such as influenza and hepatitis B [11,12,13], an increase in visceral fat in particular aggravates the COVID-19 infection [3,14,15]. This suggests that the mortality rates of the COVID-19. This relationship is likely to be more complex, as different types of fat may have different effects on COVID-19 severity in different populations due to their evolutionary history

Visceral Fat and Subcutaneous Fat

The Obesity Paradox

Sex as a Risk Factor

Findings

Conclusions