Non-Alcoholic Fatty Liver Disease and COVID-19–Two Pandemics Hitting at the Same Time

Abstract

The COVID-19 pandemic was and still is a global burden with more than 178,000,000 cases reported so far. Although it mainly affects respiratory organs, COVID-19 has many extrapulmonary manifestations, including, among other things, liver injury. Many hypotheses have been proposed to explain direct and indirect impacts of the SARS-CoV-2 virus on the liver. Studies have shown that around 15–30% of patients with COVID-19 have underlying liver disease, and 20–35% of patients with COVID-19 had altered liver enzymes at admission. One of the hypotheses is reactivation of an underlying liver disease, such as non-alcoholic fatty liver disease (NAFLD). Some studies have shown that NAFLD is associated with severe COVID-19 and poor outcome; nevertheless, other studies showed no significant difference between groups in comparing complications and clinical outcomes. Patients with NAFLD may suffer severe COVID-19 due to other comorbidities, especially cardiovascular diseases. The link between NAFLD and COVID-19 is not clear yet, and further studies and research are needed.

Impact of COVID-19 Lockdown on Non-Alcoholic Fatty Liver Disease and Insulin Resistance in Adults: A before and after Pandemic Lockdown Longitudinal Study

“…These cardiovascular and metabolic complications have caused an increase in morbidity and mortality due to hepatic and extrahepatic causes [ 45 ] as well as a greater risk of infection by COVID-19 and a worse prognosis in case of infection and requiring hospitalization [ 47 , 63 , 64 ]. The direct impact of the virus on the liver is unknown but has been seen in several studies, such as the one from Yoo H et al [ 65 ], and the study by Vranic L et al [ 66 ] showed how patients with liver pathologies had a greater risk and a worse prognosis in the case of infection by COVID-19 as well as a higher risk of the decompensation of other pathologies [ 65 , 66 ]. These hepatic alterations were also detected in our study, as shown in Table 1 , which shows alterations in the biochemical parameters in relation to the liver profile, where a statistically significant increase in transaminase levels stands out, indicating that the changes in lifestyle also affected the liver and increased the risk of infection by COVID-19 and its worse prognosis [ 67 ].…”

A Multidisciplinary Approach and Current Perspective of Nonalcoholic Fatty Liver Disease: A Systematic Review

“…It has been reported that patients with pre-existing liver diseases like NAFLD are susceptible to developing severe COVID-19 [ 38 ]. Although COVID-19 mostly affects respiratory organs, it may present with extrapulmonary manifestations such as liver injury (incidence up to 53%) [ 38 ]. In COVID-19 patients, liver injury occurs due to dysregulated and uncontrolled systemic inflammation [ 38 ].…”

“…Although COVID-19 mostly affects respiratory organs, it may present with extrapulmonary manifestations such as liver injury (incidence up to 53%) [ 38 ]. In COVID-19 patients, liver injury occurs due to dysregulated and uncontrolled systemic inflammation [ 38 ]. COVID-19 is a systemic inflammatory response syndrome that causes an uncontrolled cytokine storm that finally results in liver failure [ 38 ].…”

Non-Alcoholic Fatty Liver Disease and Extrahepatic Cancers: A Wolf in Sheep’s Clothing?

“…According to recent research, several studies support that patients with NAFLD are more prone to develop liver injury and experience more severe symptoms when infected with coronavirus disease-2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [ 95 , 96 ]. However, other studies report no significant difference in the clinical course between COVID-19 patients with and without fatty liver [ 96 , 97 ]. Indeed, further studies are required to gain a better knowledge of the interactions between COVID-19 and other diseases, such as NAFLD.…”