Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2023; 29(21): 3362-3378
Published online Jun 7, 2023. doi: 10.3748/wjg.v29.i21.3362
Association of non-alcoholic fatty liver and metabolic-associated fatty liver with COVID-19 outcomes: A systematic review and meta-analysis
Gowthami Sai Kogilathota Jagirdhar, Rakhtan K Qasba, Harsha Pattnaik, Kaanthi Rama, Akshat Banga, Shiva Teja Reddy, Anna Carolina Flumignan Bucharles, Rahul Kashyap, Praveen Reddy Elmati, Vikas Bansal, Yatinder Bains, Theodore DaCosta, Salim Surani
Gowthami Sai Kogilathota Jagirdhar, Department of Medicine, Saint Michaels Medical Center, Newark, NJ 07102, United States
Rakhtan K Qasba, Department of Medicine, Green Life Medical College and Hospital, Dhaka 1205, Bangladesh
Harsha Pattnaik, Department of Medicine, Lady Hardinge Medical College, New Delhi 110001, India
Kaanthi Rama, Shiva Teja Reddy, Department of Medicine, Gandhi Medical College, Telangana 500003, India
Akshat Banga, Department of Medicine, Sawai Man Singh Medical College, Jaipur 302004, Rajistan, India
Anna Carolina Flumignan Bucharles, Department of Medicine, Universidade Positivo, Curitiba 81290-000, PR, Brazil
Rahul Kashyap, Research, WellSpan Health, York, PA 17403, United States
Praveen Reddy Elmati, Department of Interventional Pain Medicine, University of Louisville, Louisville, KY 40292, United States
Vikas Bansal, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55902, United States
Yatinder Bains, Theodore DaCosta, Department of Gastroenterology, Saint Michaels Medical Center, Newark, NJ 07102, United States
Salim Surani, Department of Medicine, Texas A&M University, College Station, TX 77843, United States
Author contributions: Jagirdhar GSK conceived and designed the study; Jagirdhar GSK, Qasba RK, Rama K, Banga A, Reddy ST, and Flumignan Bucharles AC included studies and data extraction; Jagirdhar GSK, Qasba RK, Pattnaik H, Rama K, Banga A, Elmati PR, and Bansal V contributed to the data processing; Jagirdhar GSK, Qasba RK, Pattnaik H, Rama K, Banga A, Reddy ST, Flumignan Bucharles AC, Kashyap R, Elmati PR, Bansal V, Bains Y, and DaCosta T wrote the original manuscript; Jagirdhar GSK, Kashyap R, Bains Y, DaCosta T, and Surani S revised the paper and approved the final version.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Salim Surani, FCCP, MD, MHSc, Professor, Department of Medicine, Texas A&M University, Administration Building, 400 Bizzell St, College Station, TX 77843, United States.
Received: December 29, 2022
Peer-review started: December 29, 2022
First decision: February 15, 2023
Revised: February 25, 2023
Accepted: April 28, 2023
Article in press: April 28, 2023
Published online: June 7, 2023

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) are on the rise like any other liver disease, and tend to affect 25% of the United States population. The impact of NAFLD and MAFLD on patients with coronavirus disease 2019 (COVID-19) remains unclear.


To identify the association of NAFLD and MAFLD with mortality, hospitalization, hospital length of stay, and supplemental oxygen utilization in COVID-19 patients.


A systematic review of literature on Cochrane, Embase, PubMed, ScienceDirect, and Web of Science databases was conducted from January 2019 to July 2022. Studies that evaluated NAFLD/MAFLD using laboratory methods, noninvasive imaging, or liver biopsy were included. The study protocol was registered in PROSPERO (ID CRD42022313259) and PRISMA guidelines were followed. The National Institutes of Health quality assessment tool was used to assess the quality of the studies. Pooled analysis was conducted using software Rev Man version 5.3. The stability of the results was assessed using sensitivity analysis.


Thirty-two studies with 43388 patients were included in the meta-analysis of whom 8538 (20%) patients were observed to have NAFLD. There were 42254 patients from 28 studies included in the mortality analysis. A total of 2008 patients died from COVID-19; 837 (10.52%) in the NAFLD group and 1171 (3.41%) in the non-NAFLD group. The odds ratio (OR) was 1.38 for mortality with a 95% confidence interval (95%CI) = 0.97-1.95 and P = 0.07. A total of 5043 patients from eight studies were included in the hospital length of stay analysis. There were 1318 patients in the NAFLD group and 3725 patients in the non-NAFLD group. A qualitative synthesis showed that the mean difference in hospital length of stay was about 2 d between the NAFLD and non-NAFLD groups with a 95%CI = 0.71-3.27 and P = 0.002. For hospitalization rates, the OR was 3.25 with a 95%CI of 1.73-6.10 and P = 0.0002. For supplemental oxygen utilization, the OR was 2.04 with a 95%CI of 1.17-3.53 and P = 0.01.


Our meta-analysis suggests that there are increased odds of hospitalization, longer hospital length of stay, and increased use of supplemental oxygen in NAFLD/MAFLD patients.

Keywords: Non-alcoholic fatty liver, Fatty liver, Coronavirus, COVID-19, Metabolic-associated fatty liver

Core Tip: Metabolic-associated fatty liver disease (MAFLD) is like non-alcoholic fatty liver disease (NAFLD) and is a hepatic presentation of metabolic syndrome. They are widely prevalent. It is estimated that 25% of the United States population have this condition. The association and effect size between fatty liver disease and coronavirus disease 2019 (COVID-19) infection is still unconfirmed. The discrepancies in the available literature may be due to study design, confounding, small study population, and heterogeneity. We performed a systematic review and meta-analysis to study the impact of NAFLD/MAFLD on mortality, hospitalization, hospital length of stay, and supplemental oxygen utilization in COVID-19 patients.