The Health Impact of MAFLD, a Novel Disease Cluster of NAFLD, Is Amplified by the Integrated Effect of Fatty Liver Disease-Related Genetic Variants

Risk stratification using sarcopenia status among subjects with metabolic dysfunction-associated fatty liver disease

BACKGROUND

Sarcopenia is a significant indicator of the severity of non-alcoholic fatty liver disease. We investigated whether sarcopenia could identify subgroups with different risk of liver fibrosis and atherosclerotic cardiovascular disease (ASCVD) among subjects with metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

Subjects from the Korea National Health and Nutrition Examination Survey 2008-2011 were selected (n = 8361). Sarcopenia was defined using the sarcopenia index. Hepatic steatosis was defined as a fatty liver index ≥30. Significant liver fibrosis was defined as a fibrosis-4 index (FIB-4) ≥2.67 or the highest quartile of non-alcoholic fatty liver disease fibrosis score (NFS). High probability of ASCVD was defined as ASCVD risk score >10%.

RESULTS

The mean age was 48.5 ± 15.6 years, and 42.6% of subjects were male. The prevalence of MAFLD was 37.3% (n = 3116 of 8361), and the proportion of sarcopenic subjects was 9.9% among those with MAFLD. After adjusting for confounders, the risk of significant liver fibrosis significantly increased from non-sarcopenic subjects with MAFLD [odds ratio (OR) = 1.57 by FIB-4 and 2.13 by NFS] to sarcopenic subjects with MAFLD (OR = 4.51 by FIB-4 and 5.72 by NFS), compared with subjects without MAFLD (all P < 0.001). The risk for high probability of ASCVD significantly increased from non-sarcopenic subjects with MAFLD (OR = 1.47) to sarcopenic subjects with MAFLD (OR = 4.08), compared with subjects without MAFLD (all P < 0.001).

CONCLUSIONS

The risks of significant liver fibrosis and ASCVD differed significantly according to sarcopenic status among subjects with MAFLD. An assessment of sarcopenia might be helpful in risk stratification among subjects with MAFLD.

Editorial: International Consensus Recommendations to Replace the Terminology of Non-Alcoholic Fatty Liver Disease (NAFLD) with Metabolic-Associated Fatty Liver Disease (MAFLD)

In 2020, international consensus guidelines recommended the renaming of non-alcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD), supported by diagnostic criteria. MAFLD affects up to 25% of the global population. However, the rates of MAFLD are likely to be underestimated due to the increasing prevalence of type 2 diabetes mellitus (T2DM) and obesity. Within the next decade, MAFLD has been projected to become a major cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide, as well as the most common indication for liver transplantation in the US. This transition in terminology and clinical criteria may increase momentum and clinical evidence at multiple levels, including patient diagnosis, management, and care, and provide the basis for new research areas and clinical development for therapeutics. The diagnostic criteria for MAFLD are practical, simple, and superior to the existing NAFLD criteria for identifying patients at increased risk of developing progressive liver disease. This Editorial aims to present the historical evolution of the terminology for fatty liver disease and the advantages of diagnosis, patient management, and future research on MAFLD.

From nonalcoholic fatty liver disease to metabolic-associated fatty liver disease: Big wave or ripple?

There is some dissatisfaction with the term "nonalcoholic fatty liver disease (NAFLD)," which overemphasizes alcohol and underemphasizes the importance of metabolic risk factors in this disease. Recently, a consensus recommended "metabolic (dysfunction)-associated fatty liver disease (MAFLD)" as a more appropriate term to describe fatty liver diseases (FLD) associated with metabolic dysfunction. During the definition change from NAFLD to MAFLD, subjects with FLD and metabolic abnormalities, together with other etiologies of liver diseases such as alcohol, virus, or medication who have been excluded from the NAFLD criteria, were added to the MAFLD criteria, while subjects with FLD but without metabolic abnormality, who have been included in the NAFLD criteria, were excluded from the MAFLD criteria. This means that there is an emphasis on the metabolic dysfunction in MAFLD which may underestimate the prognostic value of hepatic steatosis itself, whereas the MAFLD criteria might better identify subjects who are at a higher risk of hepatic or cardiovascular outcomes. However, non-metabolic risk NAFLD subjects who are excluded from the MAFLD criteria are missed from the diagnosis, and their potential risk can be the cause of future diseases. Although huge controversies remain, this review focused on summarizing recent studies that compared the clinical and prognostic characteristics between subjects with NAFLD and MAFLD.

Dermatological aspects of SARS-CoV-2 infection: mechanisms and manifestations

The human infection caused by the novel SARS-CoV-2 is a public health emergency of international concern. Although the disease associated to this virus, named COVID-19, mainly affects the lungs, the infection can spread to extrapulmonary tissues, causing multiorgan involvement in severely ill patients. The broad infective capacity of SARS-CoV-2 is related to the pattern of expression of the viral entry factors ACE2 and TMPRSS2 in human tissues. As such, the respiratory and gastrointestinal tracts are at high risk for SARS-CoV-2 infection due to their high expression of ACE2 and TMPRSS2, which explains the clinical phenotype described in the vast majority of infected patients that includes pneumonia and diarrhea. Recently, preoccupation about the potential of the virus to infect the skin has been raised by dermatologists due to the increasing observations of cutaneous manifestations in patients with SARS-CoV-2 infection. Although there is little evidence of the expression of ACE2 and TMPRSS2 in the normal skin, the dermatological findings observed among COVID-19 patients warrants further investigation to delineate the mechanisms of skin affection after SARS-CoV-2 infection. Here, we provide a summary of the dermatological findings observed among patients with laboratory-confirmed SARS-CoV-2 infection based on recent reports. In addition, we analyze possible mechanisms of skin injury in COVID-19 patients and discuss about the risk of individuals with chronic skin conditions for SARS-CoV-2 infection. The present review constitutes a useful informative tool to improve our understanding of the pathophysiological mechanisms of COVID-19 and the possible implications of the current pandemic in dermatology.

Imaging biomarkers of diffuse liver disease: current status

We are happy to introduce this special issue of Abdominal Radiology on "diffuse liver disease". We have invited imaging experts to discuss various topics pertaining to diffuse liver disease, covering a vast array of imaging techniques including ultrasound (US), CT, MRI and new molecular imaging agents. Below, we briefly discussed the current status, limitations, and future directions of imaging biomarkers of diffuse liver disease.