The present study demonstrated that patients with severe COVID-19 were more susceptible to exhibit non-alcoholic fatty liver disease (NAFLD) in contrast to those with non-severe COVID-19 illness. Nevertheless, the prognosis of NAFLD (renamed as metabolic dysfunction-associated fatty liver disease (MAFLD)) is measured by the severity of liver fibrosis. The authors of the study hypothesized that patients with MAFLD with increased non-invasive liver fibrosis scores are at increased risk of severe illness from COVID-19.

The study included 310 hospitalized patients with COVID-19 between January and February 2020. Among these, 150 patients were evaluated for the association between obesity and COVID-19 severity. The exclusion criteria included patients with viral hepatitis, excessive alcohol consumption, chronic pulmonary diseases or active cancers. Clinical and laboratory data were obtained at hospital admission. All the participants were screened for hepatic steatosis by computed tomography and then diagnosed as MAFLD.

The originally validated cut-points for fibrosis-4 (FIB-4) index and NAFLD fibrosis score (NFS) were utilized to classify liver fibrosis probability as low, intermediate or high. COVID-19 severity was categorized as severe and non-severe. 

The outcome showed that out of 310 confirmed COVID-19 patients, 94 (30.3%) patients had MAFLD. Patients with MAFLD with intermediate or high FIB-4 scores had higher probablility to be older, obese, have diabetes and have higher NFS, higher liver enzymes, higher C reactive protein, along with lower levels of lymphocyte count, platelet count, triglycerides and high-density lipoprotein cholesterol in contrast to their counterparts with low FIB-4 score or those without MAFLD. Moreover, the severity of COVID-19 illness increased significantly among patients with MAFLD with intermediate or high FIB-4 scores.

The severity of COVID-19 illness was correlated to intermediate or high  FIB4 scores among patients with MAFLD. The intermediate/high NFS was related to a higher risk of severe COVID-19 illness. Additionally, increasing FIB-4 or NFS were remarkably linked to greater COVID-19 severity.

This novel study evaluated the effect of FIB-4 or NFS on COVID-19 severity in patients with imaging-defined MAFLD. These non-invasive fibrosis scores have the potential to predict histological fibrosis stage in patients with MAFLD. Thus, it can be concluded that patients with MAFLD with increased FIB-4 or NFS are more susceptible of having severe COVID-19 illness, regardless of metabolic comorbidities. Moreover, presence of MAFLD with significant/advanced fibrosis might aggravate the virus-induced cytokine storm, via hepatic release of multiple proinflammatory cytokines, which in turn increases the severity of COVID-19.

Source: Targher G, Mantovani A, Byrne CD, et al. Risk of severe illness from COVID-19 in patients with metabolic dysfunction-associated fatty liver disease and increased fibrosis scores. Gut. 2020;69:1545-1547.