Effect of Nonalcoholic Fatty Liver Disease (NAFLD) on COVID-19: A Single-Center Study of 3983 Patients With Review of Literature

Background The presence of metabolic syndrome (MS) is associated with increased disease severity in patients with coronavirus disease 2019 (COVID-19). Non-alcoholic fatty liver disease (NAFLD) associated with or without MS may be related to increased morbidity and mortality in COVID-19, but large Indian studies are lacking. The present study was carried out to assess the impact of NAFLD on the clinical outcomes in patients with COVID-19 infection. Methods All patients with COVID-19 hospitalized at a tertiary care hospital in eastern India from April 4 to December 31, 2020, were included in the study. Patients who underwent non-contrast CT (NCCT) chest were evaluated for the presence of hepatic steatosis based on a validated criterion liver attenuation (HU) value lower than the spleen, absolute liver attenuation lower than 40 HU, and liver to spleen attenuation ratio less than 1. Patients were divided into two groups, those with or without fatty liver. Baseline characteristics including age, sex, liver function tests, and outcomes including duration of hospital stay and mortality were compared. Results A total of 6003 COVID-19-positive patients were admitted during the study period. Of these patients, 214 children (<18 years) with COVID-19 infection were excluded. One hundred and eight patients with a history of significant ethanol abuse were excluded from the analysis. NCCT scan was not done in 1698 patients. Finally, 3983 patients were included in the study. They were divided into two groups depending on the presence or absence of NAFLD. Of the 3983 patients, 814 (20.4%) had NAFLD. Overall in-hospital mortality among the study group was 6.4%. The mortality rate among patients with NAFLD was 6.7% while that in patients without fatty liver was 6% (P=0.381). Similarly, the mean duration of hospital stay was also comparable between both the groups (10.63±7.2days vs 10.65±6.6 days;P=0.66). Prevalence of NAFLD was similar in survivors and non-survivors; 759 of 2981 patients (25.4%) and 55 of 188 patients 29.2% (P=0.381), respectively. On univariate analysis, male sex, older age, elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT) along with low serum albumin and low absolute eosinophil counts (AEC) were associated with higher mortality. However, on multivariate analysis, only older age, male sex, and low albumin levels were associated with higher mortality. Surprisingly, a sub-group analysis showed that females without NAFLD were at a higher risk of mortality than those with fatty liver (4.9% vs 12.3%; P=0.006). Similarly, patients with lower AST levels had higher mortality compared to patients with significantly elevated AST levels (more than two times the upper limit of normal (ULN)), irrespective of the presence of fatty liver. Conclusions The prevalence of fatty liver in severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infected patients is similar to the general population in India, the presence of which is not a predictor of severe disease. However, mortality is higher in males and elderly patients.