Severe illness of COVID-19 has been associated with numerous factors like older age, pre-existing lung disease, diabetes mellitus, cardiovascular disease, and obesity. Another yet important comorbid condition that is being evaluated for its impact on COVID-19 severity is Chronic liver disease (CLD), which has been reported in nearly 2%–11% of COVID-19 patients. CLDs are predominated with Non-alcoholic fatty liver disease (NAFLD) worldwide, which accounts for nearly 6.3%-45% of the general population globally. 

Association of liver fibrosis with the clinical outcomes of COVID-19 patients with non-alcoholic fatty liver disease (NAFLD) is scantily explained. A study determined the association of NAFLD fibrosis score (NFS)–determined liver fibrosis with clinical outcomes of COVID-19 patients with NAFLD.

The researchers diagnosed the NAFLD by the Hepatic Steatosis Index (HSI) in the absence of other causes of chronic liver diseases. They utilized NFS to evaluate the severity of liver fibrosis. The study enrolled 86 COVID-19 patients with NAFLD with a median age of 43.5 years. 58.1% of the patients were male. 

The observation of the study was as follows=

• 2% of patients had advanced liver fibrosis according to the NFS.
• Multivariate analysis stipulated concurrent diabetes and advanced liver fibrosis to be an independent risk factor of severe illness in COVID-19 patients with NAFLD.

The researchers highlighted the lack of knowledge of the exact pathophysiology of advanced liver fibrosis (ALF) contributing to a more severe COVID-19 illness in NAFLD patients, further pointing towards several proposed potential mechanisms. Systemic inflammatory response syndrome, particularly the “cytokine storm,” is regarded to be one of the important pathophysiologic mechanisms for the development of severe illness in COVID-19. Existing ALF might exacerbate the virus-induced “cytokine storm” thus contributing to severe COVID-19 through the hepatic release of proinflammatory cytokines. The researchers warranted more studies to explore the mechanisms of advanced NAFLD contributing to the COVID-19 disease process.

Thus it was concluded that the NAFLD patients with NFS-determined advanced liver fibrosis are at higher risk of severe COVID-19.