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.

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

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.

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.

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.

The available evidence on the connection between excessive alcohol consumption and diabetes is controversial. Therefore, the primary objective of this investigation was to examine the connection between excessive alcohol consumption and incident diabetes in a Japanese population through the utilization of propensity score matching (PSM) analysis. Our retrospective cohort study encompassed a sample of 15,464 Japanese individuals who were initially free of diabetes between the years 2004 and 2015. The study utilized comprehensive medical records of individuals who underwent a physical examination. Employing a one:one PSM analysis, the current research included 2298 individuals with and without excessive alcohol consumption. Furthermore, a doubly robust estimation method was employed to ascertain the connection between excessive alcohol consumption and diabetes. The findings revealed that individuals with excessive alcohol consumption exhibited a 73% higher likelihood of developing diabetes (HR = 1.73, 95% CI 1.08-2.77). Furthermore, upon adjusting for variables, the PSM cohort demonstrated that individuals with excessive alcohol consumption had a 78% increased risk of developing diabetes in comparison to those with non-excessive alcohol consumption (HR = 1.78, 95% CI 1.08-2.93). Individuals with excessive alcohol consumption were found to have a 73% higher risk of developing diabetes compared to those with non-excessive alcohol consumption, even after controlling for propensity score (HR = 1.73, 95% CI 1.08-2.78). Participants in the PSM cohort with excessive alcohol consumption had a 73% higher risk of developing diabetes than those with non-excessive alcohol consumption after controlling for confounding factors. These findings underscore the importance of alcohol consumption guidelines aimed at reducing excessive drinking. Clinicians should be vigilant in screening for alcohol use in patients, particularly those at risk for diabetes, and provide appropriate counseling and resources to support alcohol reduction.

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.

It is important to identify risk factors for poor outcomes of coronavirus disease 2019 (COVID-19) patients. Currently, the correlation between non-alcoholic fatty liver disease (NAFLD) and COVID-19 outcomes has not been established. This study was conducted to determine the association between NAFLD and in-hospital outcomes of COVID-19 patients. The systematic searches were conducted by using PubMed and the Europe PMC databases and particular keywords were used as of December 10, 2020. Further searches were conducted up to 2022. All articles that include data about COVID-19 and fatty liver disease were collected. Statistical analysis was performed by using Review Manager 5.4 and Comprehensive Meta-Analysis version 3 software. A total of 7,210 COVID-19 patients from 18 studies were included in the final analysis. Meta-analysis revealed that NAFLD increased the risk of developing poor in-hospital outcome (pooled both severe disease and death) in COVID-19 patients (RR 1.42; 95%CI: 1.17-1.73, p<0.001, I2=84%, random-effect modeling). Subgroup analysis however found that having NAFLD only increased the chance of getting severe COVID-19 (RR 1.67; 95%CI: 1.32-2.13, p<0.001, I2=86%, random-effect modeling) and not mortality (RR 1.00; 95%CI: 0.68-1.47, p=0.98, I2=80%, random-effect modeling). Meta-regression suggested that age (p=0.001) and diabetes (p=0.029) were significantly influenced the relationship between NAFLD and in-hospital outcomes of COVID-19 (pooled both severe disease and mortality). The weaker association of NAFLD and in-hospital outcomes of COVID-19 was found for studies with median age ≥45 years old (RR 1.29) when compared to studies with median age <45 years old (RR 2.96). In addition, studies with the prevalence of diabetes ≥25% (RR 1.29) had a weaker association with in-hospital outcomes when compared to studies with diabetes prevalence <25% (RR 1.85). In conclusion, NAFLD increased the risk of chance of getting severe COVID-19 and therefore it should be evaluated closely to reduce the chance of getting severe COVID-19.

The novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has become a global challenge of unprecedented nature since December 2019. Although most patients with COVID-19 exhibit mild clinical manifestations and upper respiratory tract involvement, in approximately 5%-10% of patients, the disease is severe and involves multiple organs, leading to multi-organ dysfunction and failure. The liver and gastrointestinal tract are also frequently involved in COVID-19. In the context of liver involvement in patients with COVID-19, many key aspects need to be addressed in both native and transplanted organs. This review focuses on the clinical presentations and laboratory abnormalities of liver function tests in patients with COVID-19 with no prior liver disease, patients with pre-existing liver diseases and liver transplant recipients. A brief overview of the history of COVID-19 and etiopathogenesis of the liver injury will also be described as a prelude to better understanding the above aspects.