Letter to the Editor: Obesity as a risk factor for greater severity of COVID-19 in patients with metabolic associated fatty liver disease.

Dear Sir,

We read with interest the article by K·I Zheng et al. [1], we congratulate the authors for their work and conclusions. Although the definition of obesity in this article is slightly different from the internationally accepted criteria, however, the authors had successfully used the data to answer the research question.

Many studies had reported non-alcoholic fatty liver disease [NAFLD] and non-alcoholic steatohepatitis [NASH] in association with obesity [[2], [3], [4], [5]]. These two conditions are not specific to the obese or overweight patients but also affecting non-obese population with risk of progression to cirrhosis, fibrosis and hepatocellular cancer [6].

The NAFLD and NASH have been diagnosed frequently with liver biopsies, but also liver imaging cross sectional studies which were provided the diagnosis and the assessment of the disease progression. Not only, NASH and NAFLD are important predictive factors for the outcomes in acute and chronic disease processes but also the obesity surgery and its complications [7]. We think that the authors had reached the correct conclusion indirectly, as obesity is the primary aetiology for the liver disease [NASH, NAFLED] and rarely considered as independent conditions. When they coexist, they do so because of obesity.

Several other studies have reported obesity as a significant factor for mortality in Covid-19 patients [[8], [9], [10]].This subject is more important in the current Covid-19 crisis knowing the pandemic of obesity. In addition to the known defective immune system in the obesity, the virulence of Covid-19 and the differences in the incidence of obesity across the world, it is not clear what is the magnitude /severity of liver disease could add to production of critical illness like severe pneumonia. We believe more powerful studies are needed to confirm why obesity is a risk factor for critical illness and or mortality in Covid-19. This will help to reduce mortality in this vulnerable group of patients.

Declaration of competing interest

Authors confirm no conflict of interest and no funding for this paper.