Impact of non-alcoholic fatty liver disease on coronavirus disease 2019: A systematic review.

Background: Many studies have revealed a link between non-alcoholic fatty liver disease (NAFLD) and coronavirus disease 2019 (COVID-19), making understanding the relationship between these two conditions an absolute requirement.

Aim: To provide a qualitative synthesis on the currently present data evaluating COVID-19 and NAFLD.

Methods: This systematic review was conducted in accordance with the guidelines provided by preferred reporting items for systematic reviews and meta-analyses and the questionnaire utilized the population, intervention, comparison, and outcome framework. The search strategy was run on three separate databases, PubMed/MEDLINE, Scopus, and Cochrane Central, which were systematically searched from inception until March 2024 to select all relevant studies. In addition, ClinicalTrials.gov, Medrxiv.org, and Google Scholar were searched to identify grey literature.

Results: After retrieval of 11 studies, a total of 39282 patients data were pooled. Mortality was found in 11.5% and 9.4% of people in NAFLD and non-NAFLD groups. In all, 23.2% of NAFLD patients and 22% of non-NAFLD admissions diagnosed with COVID-19 were admitted to the intensive care unit, with days of stay varying. Ventilatory support ranged from 5% to 40.5% in the NAFLD cohort and from 3.1% to 20% in the non-NAFLD cohort. The incidence of acute liver injury showed significance. Clinical improvement on days 7 and 14 between the two classifications was significant. Hospitalization stay ranged from 9.6 days to 18.8 days and 7.3 days to 16.4 days in the aforementioned cohorts respectively, with 73.3% and 76.3% of patients being discharged. Readmission rates varied.

Conclusion: Clinical outcomes except mortality consistently showed a worsening trend in patients with NAFLD and concomitant COVID-19. Further research in conducting prospective longitudinal studies is essential for a more powerful conclusion.