BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) patients represent a vulnerable population that may be susceptible to more severe COVID-19. Moreover, not only the underlying NAFLD may influence the progression of COVID-19, but the COVID-19 may affect the clinical course of NAFLD as well. However, comprehensive evidence on clinical outcomes in patients with NAFLD is not well characterized. OBJECTIVES: To systematically review and meta-analysis the evidence on clinical outcomes in NAFLD patients with COVID-19. METHODS: MEDLINE, EMBASE, and Cochrane Central were searched from inception through November 2020. Epidemiological studies assessing the clinical outcomes in COVID-19 patients with NAFLD were included. Newcastle-Ottawa Scale (NOS) was used to assess study quality. Generic inverse variance method using RevMan was used to determine the pooled estimates using the random-effects model. RESULTS: Fourteen studies consisting of 1851 NAFLD patients, were included. Significant heterogeneity was observed among the studies, and studies were of moderate to high quality [mean, (range):8 (6, 8)]. For NAFLD patients, the adjusted odds ratio (aOR) for the severe COVID-19 was 2.60 (95%CI:2.24-3.02; p < 0.001) (studies,n:8), aOR for admission to ICU due to COVID-19 was 1.66 (95%CI:1.26-2.20; p < 0.001) (studies,n:2), and aOR for mortality for was 1.01 (95%CI:0.65-1.58; p = 0.96) (studies,n:2). CONCLUSIONS: An increased risk of severe COVID-19 infection and admission to ICU due to COVID-19 with no difference in mortality was observed between NAFLD and non-NAFLD patients. Future studies should include the mortality outcome to conclusively elucidate the impact of NAFLD in patients with COVID-19.

Cochrane Czech Republic Czech National Centre for Evidence Based Healthcare and Knowledge Translation Institute of Biostatistics and Analyses Faculty of Medicine Masaryk University Brno Czech Republic

Menzies Institute for Medical Research University of Tasmania Hobart Australia

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