Non-alcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease in developed countries because of the obesity epidemic. The disease increases liver-related morbidity and mortality, and often increases the risk for other comorbidities, such as type 2 diabetes and cardiovascular disease. Insulin resistance related to metabolic syndrome is the main pathogenic trigger that, in association with adverse genetic, humoral, hormonal and lifestyle factors, precipitates development of NAFLD. Biochemical markers and radiological imaging, along with liver biopsy in selected cases, help in diagnosis and prognostication. Intense lifestyle changes aiming at weight loss are the main therapeutic intervention to manage cases. Insulin sensitizers, antioxidants, lipid lowering agents, incretin-based drugs, weight loss medications, bariatric surgery and liver transplantation may be necessary for management in some cases along with lifestyle measures. This review summarizes the latest evidence on the epidemiology, natural history, pathogenesis, diagnosis and management of NAFLD.

The worldwide pandemic of COVID-19, caused by the virus SARS-CoV,-2 has continued to progress, and increasing information is becoming available about the incidence of digestive symptoms as well as abnormal liver-associated enzymes in patients who are infected. These are postulated to be related to the virus's use of ACE-2 receptors located on certain intestinal cells, cholangiocytes, and hepatocytes. This brief review summarizes the available limited data on digestive manifestations of COVID-19. A significant proportion of COVID-19 patients can present initially with only digestive complaints. The most common digestive symptoms are anorexia, nausea, vomiting, and diarrhea. Liver-related transaminases are elevated in a substantial proportion of patients, although generally only mildly elevated. Currently there is no firm evidence to suggest that severity of digestive symptoms corresponds to severity of COVID-19 clinical course, however, more severe alterations in liver enzymes may correlate with worse clinical course. Given use of antiviral and antibacterial agents in sicker patients, drug-induced liver injury cannot be ruled out either in these cases. Although viral RNA can be detected in stool, it is unclear whether fecal-oral transmission can be achieved by the virus. As further data becomes available, our understanding of the digestive manifestations of COVID-19 will continue to evolve.

T he reported prevalence of gastrointestinal (GI) symptoms, including anorexia, diarrhea, nausea, vomiting, and abdominal pain, in severe acute respiratory syndrome coronavirus 2 infection has been highly variable, ranging from 5% to 61%. 1-7 Although the Centers for Disease Control and Prevention guidelines for testing for coronavirus disease 2019 (COVID-19) include vomiting and diarrhea, to our knowledge, all studies to date have been retrospective, and none have evaluated the prevalence of GI symptoms among patients who tested negative for COVID-19. In this prospective case-control study, we compared the prevalence of GI symptoms between those who tested positive and negative for COVID-19 and determined the association between GI symptoms and COVID-19 diagnosis or outcomes. Methods This was a prospective case-control study performed at a single tertiary care hospital in Baltimore, Maryland, after institutional review board approval. The study population included all adult patients who tested positive (case patients) or negative (control individuals) for COVID-19 by nasopharyngeal swab between March 9, 2020, and April 15, 2020. A telephone survey was conducted to obtain information including demographics, comorbid conditions, GI symptoms, respiratory symptoms, fever, gustatory symptoms, olfactory symptoms, and need for hospitalization by using a predesigned questionnaire. The primary outcome was the prevalence of GI symptoms in COVID-19-positive and-negative patients, and the secondary outcomes were to determine the utility of GI symptoms for COVID-19 screening and the association of GI symptoms with need for hospitalization. Logistic regression and univariate followed by multivariable analysis using a backward model selection approach were conducted to evaluate risk factors of COVID-19, and the area under the receiver operating characteristic (AUROC) for COVID-19 using a combination of different symptoms was determined.

The worldwide pandemic of COVID-19, caused by the virus SARS-CoV-2, continues to cause significant morbidity and mortality in both low-and high-income countries. Although COVID-19 is predominantly a respiratory illness, other systems including gastrointestinal (GI) system and liver may be involved because of the ubiquitous nature of ACE-2 receptors in various cell lines that SARS-CoV-2 utilizes to enter host cells. It appears that GI symptoms and liver enzyme abnormalities are common in COVID-19. The involvement of the GI tract and liver correlates with the severity of disease. A minority (10-20%) of patients with COVID-19 may also present initially with only GI complaints. The most common GI symptoms are anorexia, loss of smell, nausea, vomiting, and diarrhea. Viral RNA can be detected in stool in up to 50% of patients, sometimes even after pharyngeal clearance, but it is unclear whether fecal-oral transmission occurs. Liver enzymes are elevated, usually mild (2-3 times), in a substantial proportion of patients. There are many confounding factors that could cause liver enzyme abnormalities including medications, sepsis, and hypoxia. Although infection rates in those with preexisting liver disease are similar to that of general population, once infected, patients with liver disease are more likely to have a more severe disease and a higher mortality. There is a paucity of objective data on the optimal preventive or management strategies, but few recommendations for GI physicians based on circumstantial evidence are discussed.