Metabolic dysfunction associated fatty liver disease: The new nomenclature and its impact

Arterial stiffness, high fasting glucose, and fatty liver as risk factors for visceral obesity in middle-aged Chinese individuals: a cross-sectional study

The prevalence of obesity is increasing rapidly worldwide, particularly in Asia. Visceral obesity, characterized by intra-abdominal fat accumulation, is a precursor to metabolic syndrome, encompassing hyperglycemia, dyslipidemia, and hypertension, which elevate the risk of atherosclerosis and cardiovascular disease. A visceral fat area (VFA) of ≥100 cm2 is a recognized threshold for diagnosing obesity-related metabolic syndrome. This study aimed to identify independent risk factors for VFA ≥100 cm2 in middle-aged Chinese individuals from the general population. We analyzed data from 148 participants (mean age: 49.3 ± 10.8 years; 54% male) who underwent health check-ups. VFA and subcutaneous fat area were assessed using computed tomography, while arterial stiffness and fatty liver were evaluated via brachial-ankle pulse wave velocity (baPWV) and abdominal ultrasonography, respectively. Between-group comparisons (VFA ≥100 cm2 vs. VFA <100 cm2) were conducted using unpaired t-tests and Mann-Whitney U tests, and logistic regression analysis identified risk factors. Multivariable regression analysis revealed that baPWV ≥1,400 cm/s (odds ratio [OR] = 5.71, p = 0.011), waist circumference ≥85 cm (OR = 5.46, p = 0.026), fasting blood glucose (FBG) ≥100 mg/dL (OR = 5.69, p = 0.030), male sex (OR = 12.79, p = 0.029), and fatty liver (OR = 3.99, p = 0.042) were significant independent risk factors for VFA ≥100 cm2. Among these, baPWV ≥1,400 cm/s was the most significant, showing a positive correlation with VFA (r = 0.365, p < 0.001). Visceral obesity (VFA ≥100 cm2) is a critical target for interventions addressing metabolic syndrome, metabolic dysfunction-associated fatty liver disease (MAFLD), and cardiovascular disease, particularly in males.

HEPNET Position Statement-I, Case Definition, Classification, Screening & Diagnosis of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) in Pakistan: A Resource for Primary and Secondary Care Physicians

The Hep-Net position paper comes at a significant time in the history of Metabolically Associated Fatty Liver Disease (MAFLD) due to the rapid rise in this disease entity in the past decade. Metabolically Associated Fatty Liver Disease, by its very name, encompasses several common metabolic disease entities, top among those being diabetes and obesity. For Pakistan, the situation is serious as it is among the top 10 countries globally regarding the prevalence of obesity and number one in terms of diabetes, with over a quarter of adults affected. There remains slight ambiguity as regards the nomenclature of MAFLD, with western societies preferring to remove the word "fatty" and substitute with `'steatotic" i.e. MASLD. Regardless of names/titles the metabolic nature of the disease and its management remains the same and fortunately, that is something where universal consensus is present. Under the umbrella of Hep-Net, eminent hepatologists from all over Pakistan have pooled their efforts to formulate guidelines that are specifically tailored to the Pakistani population, its specific lifestyle and relevant interventions that are needed to treat fatty/steatotic liver disease. By virtue of its multi-systemic consequences, metabolic fatty liver disease represents the most significant and expensive disease entity, globally. Prevention, through public education and timely intervention in diagnosed cases will serve to avert a healthcare storm that will far outweigh viral hepatitis.

Dietary quality, perceived health, and psychological status as key risk factors for newly developed metabolic dysfunction-associated steatotic liver disease in a longitudinal study

OBJECTIVES

This study investigated biomarkers in individuals with newly developed metabolic dysfunction-associated steatotic liver disease (ND-MASLD) and examined the interplay between genetic predisposition and environmental factors using a machine learning approach in a large longitudinal study.

METHODS

Participants were classified into four groups based on metabolic dysfunction-associated steatotic liver disease (MASLD) status between the first and second measurements with an approximate 5-y gap. A model was developed to identify early-stage biomarkers of ND-MASLD (n = 1603). Nutrient intake, dietary patterns, genetic variants, and psychosocial factors were compared among the no MASLD (n = 60 081), recovered MASLD (n = 3181), persistent MASLD (n = 670), and ND-MASLD (n = 1603) groups. Their association with ND-MASLD was also predicted using a machine learning approach.

RESULTS

The model incorporating ND-MASLD status, age, sex, dietary inflammatory index, and metabolic syndrome (MetS), especially low high-density lipoprotein cholesterol and hypertriglyceridemia, at the second measurement demonstrated an optimal fit. High carbohydrate intake with a high glycemic index was associated with elevated ND-MADSLD risk. Fatty liver index was lower in persistent MASLD followed by ND-MASLD, recovered MASLD, and no MASLD. Participants in the ND-MASLD group had lower vitamin D and total isoflavonoid intake and a lower modified healthy eating index, indicating unhealthy diets. The XGBoost and deep neural network models identified age, sex, MetS components, dietary antioxidants, self-rated health, psychological well-being indexes, and serum liver enzyme levels at the second measurement as significant predictors of ND-MASLD. However, polygenic risk scores were not included.

CONCLUSIONS

Early-stage biomarkers of ND-MASLD were closely linked to MetS incidence. Dietary quality, perceived health status, and psychological stress emerged as potential targets for MASLD prevention strategies, with lifestyle modifications potentially overriding genetic predispositions. The results indicate that preventive strategies about lifestyle modification should be developed for MASLD.

[Different Types of Obesity Play a Modifying Role in the Association Between Physical Activity and Metabolic Dysfunction-Associated Fatty Liver Disease]

Objective

To explore the association between physical activity levels and metabolic dysfunction-associated fatty liver disease (MAFLD) and the modifying effects of different types of obesity.

Methods

A cross-sectional study was conducted on 19925 participants recruited from the Chengdu sub-cohort of the Southwest China Natural Population Cohort. The participants were recruited between 2018 and 2019. The association between physical activity and MAFLD prevalence was examined using the inverse probability weighting (IPW) method based on the generalized propensity score (GPS). The odds ratios (OR) and the 95% confidence interval (CI) for moderate and vigorous physical activity were calculated using the mild physical activity group as a reference. A restricted cubic spline function was used to model the exposure-response relationship between physical activity and MAFLD risk. The potential modifying effects of obesity types on the association between physical activity and MAFLD were evaluated in male and female populations.

Results

The prevalence of MAFLD was 17.30%. Compared to those engaging in mild physical activity, individuals participating in vigorous and moderate physical activities had a lower risk of MAFLD, with OR (95% CI) being 0.76 (0.67, 0.86) and 0.85 (0.76, 0.94), respectively. The exposure-response relationship showed a nonlinear association between physical activity and MAFLD risks (P nonlinearity = 0.005). The protective effect of physical activity against MAFLD was observed when physical activity reached approximately 20 METs-h/d. However, when physical activity exceeded 70 METs-h/d, no significant effect on MAFLD risk was observed. Among the female population, obesity type significantly modified the association between physical activity and MAFLD (P < 0.05). In females with central obesity, the protective effect of physical activity on MAFLD showed a threshold effect, with the lowest disease risk observed at approximately 25 METs-h/d. However, physical activity exceeding 37.5 METs-h/d showed no statistically significant association with MAFLD risk. In contrast, for females with peripheral obesity, high levels of physical activity had limited effects on reducing MAFLD risks.

Conclusion

Moderate physical activity can significantly reduce the risk of MAFLD, and the obesity types can modify this association. It is recommended that individuals engage in approximately 20-70 METs-h/d of physical activity. For females with central obesity, physical activity should not exceed 37.5 METs-h/d, while for females with peripheral obesity, it should not exceed 30 METs-h/d.

County-Level Food Insecurity and Hepatocellular Carcinoma Risk: A Cross-Sectional Analysis

Food insecurity (FI) is associated with several known hepatocellular carcinoma (HCC) risk factors, but few studies have directly examined FI in association with HCC risk. We aimed to investigate whether county-level FI is associated with HCC risk. We used data from 21 registries in the Surveillance Epidemiology and End Results database to obtain county-level counts of HCC cases from 2018 to 2021. We obtained the county-level FI rates for 2018-2021 from Feeding America's Map the Meal Gap. We used multi-level Poisson regression models with robust standard errors to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Overall, a one-standard-deviation (SD) increase in county-level FI was associated with an 8% increase in HCC risk in the fully adjusted model (IRR = 1.08, 95% CI = 1.06, 1.10). When stratified by age at diagnosis, a one-SD increase in county-level FI was associated with a 2% higher risk of HCC in the ≥65 age group (IRR = 1.02, 95% CI = 1.00, 1.05) and a 15% higher risk in the <65 age group (IRR = 1.15, 95% CI = 1.11, 1.19; interaction p-value < 0.001). If confirmed in other studies, these findings support the need for interventions and policies addressing FI in populations at increased risk for HCC.

Assessing Mortality Disparities Among Non-Alcoholic Fatty Liver Disease Metabolic Dysfunction Fatty Liver Disease and Metabolic Dysfunction-Associated Liver Disease: A Comprehensive Meta-Analysis

Non-alcoholic fatty liver disease (NAFLD) has emerged as a major global health concern due to its association with increased mortality. While previous studies have indicated a link between NAFLD and mortality, variations in risk factors such as age, sex, and disease severity warrant a comprehensive meta-analysis to clarify these associations. This meta-analysis aimed to evaluate the overall cardiovascular disease (CVD) mortality risk associated with NAFLD, considering various subgroups defined by age, sex, disease severity, presence of cirrhosis or fibrosis, study quality, and follow-up duration. A systematic search of eight studies was conducted to assess the hazard ratios (HRs) for all-cause and CVD mortality associated with NAFLD. Heterogeneity among studies was evaluated using the I² statistic, and subgroup analyses were performed based on participant age, sex, disease severity, presence of cirrhosis or fibrosis, study quality, and follow-up duration. NAFLD was significantly associated with an increased risk of all-cause mortality (HR = 1.34, 95% CI: 1.17-1.54, I² = 80.0%). Subgroup analyses revealed that individuals aged ≥50 years (HR = 1.50, 95% CI: 1.31-1.73) and males (HR = 1.43, 95% CI: 1.29-1.59) had a higher mortality risk. Patients with nonalcoholic steatohepatitis (NASH) showed a significant association with both overall (HR = 1.37, 95% CI: 1.14-1.65) and CVD mortality (HR = 1.56, 95% CI: 1.25-1.97). The presence of cirrhosis or fibrosis further elevated the risk of mortality (HR = 3.22, 95% CI: 2.40-4.33). However, NAFLD was not significantly associated with CVD mortality in the overall analysis (HR = 1.13, 95% CI: 0.92-1.38). Heterogeneity was high across most subgroups, indicating varying effects based on study characteristics. NAFLD is significantly associated with increased all-cause mortality, particularly in older individuals, males, and those with NASH or cirrhosis/fibrosis. The association with CVD mortality was not significant in the overall analysis but was evident in specific subgroups. These findings underscore the importance of early detection and tailored management of NAFLD to mitigate its impact on mortality. Further research is needed to elucidate the mechanisms linking NAFLD with adverse health outcomes and to develop effective interventions.

Arterial stiffness progression in metabolic dysfunction-associated fatty liver disease subtypes: A prospective cohort study

BACKGROUND AND AIMS

We aimed to investigate the correlation and to explore which MAFLD subtypes have the greatest influence on progression of arterial stiffness risk.

METHODS AND RESULTS

Using data from a health examination-based cohort, a total of 12,129 participants who underwent two repeated health examinations that included brachial-ankle pulse wave velocity (baPWV) from 2012 to 2020 were enrolled. Participants were separated into non-MAFLD, overweight/obese (OW-MAFLD), lean/normal weight (lean-MAFLD) and diabetes (DM-MAFLD) groups. Among the participants with a median follow-up of 2.17 years, 4511 (37.2%) participants had MAFLD at baseline, among which 3954 (87.7%), 123 (2.7%), and 434 (9.6%) were OW-, lean- and DM-MAFLD, respectively. Analyses using linear regression models confirmed that compared with the non-MAFLD group, the elevated baPWV change rates (cm/s/year) were 12.87 (8.81-16.94), 25.33 (7.84-42.83) and 38.49 (27.88-49.10) in OW, lean and DM-MAFLD, respectively, while the increased change proportions (%) were 1.53 (1.10-1.95), 3.56 (1.72-5.40) and 3.94 (2.82-5.05), respectively. Similar patterns were observed when these two baPWV parameters were transformed in the form of the greatest increase using Cox proportional hazards model analyses. Furthermore, the risk of arterial stiffness progression across MAFLD subtypes presented a significant, gradient, inverse relationship in the order of DM-, lean-, OW with metabolic abnormalities (MA)-, and OW without MA-MAFLD.

CONCLUSION

MAFLD, especially DM-MAFLD and lean-MAFLD, was significantly associated with arterial stiffness progression, providing evidence that stratification screening and surveillance strategies for CVD risk have important clinical implications.

Association between non-alcoholic fatty liver disease and the risk of pulmonary nodules in patients with intestinal polyps

Background

Associations between metabolic risk factors and lung cancer remain elusive, and evidence on the linkage between non-alcoholic fatty liver disease (NAFLD) and pulmonary nodules is limited. This study sought to examine the independent association between NAFLD and the risk of pulmonary nodules.

Methods

Cross-sectional analyses of 1,119 patients with intestinal polyps hospitalized at the Department of Gastroenterology, Minhang District Central Hospital of Shanghai, China, were conducted. NAFLD was diagnosed based on hepatic ultrasonography or computed tomography (CT) findings of hepatic steatosis, with exclusion criteria ensuring patients had no history of significant alcohol consumption, viral infections, or hepatic autoimmune diseases. The currently accepted definition of a pulmonary nodule is a solid or sub-solid shadow ≤3 cm in diameter that appears as a solid or semi-solid pattern on a chest CT scan (our specific treatment is pulmonary nodule size: 5 mm to 3 cm). Adjusted 95% confidence intervals (CIs) and odds ratios (ORs) for NAFLD and the clinical features connected with pulmonary nodule risk were determined using a multivariable logistic regression analysis.

Results

Among the 979 intestinal polyp patients, the prevalence rates of NAFLD and pulmonary nodules were 25.9% and 32.8%, respectively. Patients with pulmonary nodules exhibited higher rates of NAFLD (31.5% vs. 23.3%, P=0.006) and obesity (41.4% vs. 32.5%, P=0.006) compared to those without pulmonary nodules. After removing all the possible confounding variables, the adjusted ORs for NAFLD, an older age, smoking, and obesity were 1.370 (95% CI: 1.006-1.867, P=0.04), 1.022 (95% CI: 1.010-1.033), 1.599 (95% CI: 1.033-2.475), and 1.410 (95% CI: 1.057-1.880), respectively (all P values <0.05). NAFLD showed a significant association with an increased risk of pulmonary nodules.

Conclusions

NAFLD was independently linked to an increased incidence of pulmonary nodules in intestinal polyp patients, which emphasizes the importance of screening and managing these conditions in lung cancer prevention.

Evidence That Peripheral Leptin Resistance in Omental Adipose Tissue and Liver Correlates with MASLD in Humans

Leptin regulates lipid metabolism, maximizing insulin sensitivity; however, peripheral leptin resistance is not fully understood, and its contribution to metabolic dysfunction-associated steatotic liver disease (MASLD) is unclear. This study evaluated the contribution of the leptin axis to MASLD in humans. Forty-three participants, mostly female (86.04%), who underwent cholecystectomy were biopsied. Of the participants, 24 were healthy controls, 8 had MASLD, and 11 had metabolic dysfunction-associated steatohepatitis (MASH). Clinical and biochemical data and the gene expression of leptin, leptin receptor (LEPR), suppressor of cytokine signaling 3 (SOCS3), sterol regulatory element-binding transcription factor 1 (SREBF1), stearoyl-CoA desaturase-1 (SCD1), and patatin-like phospholipase domain-containing protein 2 (PNPLA2), were determined from liver and adipose tissue. Higher serum leptin and LEPR levels in the omental adipose tissue (OAT) and liver with MASH were found. In the liver, LEPR was positively correlated with leptin expression in adipose tissue, and SOCS3 was correlated with SREBF1-SCD1. In OAT, SOCS3 was correlated with insulin resistance and transaminase enzymes (p < 0.05 for all. In conclusion, we evidenced the correlation between the peripheral leptin resistance axis in OAT-liver crosstalk and the complications of MASLD in humans.

Changes in the terminology and diagnostic criteria of non-alcoholic fatty liver disease: Implications and opportunities

Fatty liver disease (FLD) is a highly prevalent pathological liver disorder. It has many and varied etiologies and has heterogeneous clinical course and outcome. Its proper nomenclature and classification have been problematic since its initial recognition. Traditionally, it was divided into two main categories: Alcohol-associated liver disease and nonalcoholic FLD (NAFLD). Among these, the latter condition has been plagued with nomenclature and classification issues. The two main objections to its use have been the use of negative (non-alcoholic) and stigmatizing (fatty) terms in its nomenclature. Numerous attempts were made to address these issues but none achieved universal acceptance. Just recently, NAFLD has received a new nomenclature from an international collaborative effort based on a rigorous scientific methodology. FLD has been renamed steatotic liver disease (SLD), and NAFLD as metabolic dysfunction-associated SLD. Metabolic dysfunction-associated steatohepatitis was chosen as the replacement terminology for non-alcoholic steatohepatitis. This is a significant positive change in the nomenclature and categorization of FLD and will likely have a major impact on research, diagnosis, treatment, and prognosis of the disease in the future.

Association between the traditional Chinese medicine constitution and metabolic dysfunction-associated fatty liver disease in older people: A cross-sectional study

Background

Few studies have focused on the relationship between the traditional Chinese medicine constitution (TCMC) and metabolic dysfunction-associated fatty liver disease (MAFLD) in older populations. We sought to investigate the distribution of MAFLD and the TCMC in older people, and provide a theoretical basis for TCMC-based management of MAFLD in this population.

Methods

A cross-sectional study was conducted among older (≥65 years) individuals in Zhongshan, China. Information on common sociodemographic characteristics, medical history, anthropometric measurements, and the TCMC was collected. The chi-square test, multivariable logistic regression analysis, subgroup analysis, and inverse probability weighting of the propensity score were used to explore the relationship between MAFLD and the TCMC.

Results

Of 7085 participants, 1408 (19.9 %) had MAFLD. The three most common TCMC types in MAFLD patients were "phlegm-dampness", "gentleness", and "yin-deficiency". After adjustment for gender, age, tobacco smoking, alcohol consumption, body mass index, abnormal waist-to-hip ratio, hypertension, diabetes mellitus, and dyslipidemia, MAFLD was positively associated with the phlegm-dampness constitution (PDC) (ORadjusted (95 % CI) = 1.776 (1.496-2.108), P < 0.001), and negatively correlated with the qi-depression constitution (0.643 (0.481-0.860), 0.003). A stronger correlation between the PDC and MAFLD was observed in men compared with women (ORadjusted = 2.04 (95%CI = 1.47-2.84) vs. 1.70 (95%CI = 1.39-2.08), Pinteraction = 0.003) as well as between people who smoked tobacco and non-tobacco-smoking individuals (2.11 (1.39-3.21) vs. 1.75 (1.45-2.12), 0.006).

Conclusions

A positive relationship was observed between MAFLD and the PDC in older people living in Zhongshan. Early detection and treatment of the PDC (especially in men and smokers) could prevent the occurrence and development of MAFLD.

Fuzhuan brick tea ameliorates hepatic steatosis and steatohepatitis through gut microbiota-derived aryl hydrocarbon receptor ligands in high-fat diet-induced obese mice

High-fat diet (HFD) induced obesity and its associated conditions, such as hepatic steatosis and steatohepatitis, are major health concerns worldwide. Previous studies have reported the excellent efficiency of Fuzhuan brick tea (FBT) in attenuating HFD-induced obesity and metabolic disorders. In this study, we investigated the effects of FBT on hepatic steatosis and simple steatohepatitis in HFD-induced obese mice, as well as the metabolic function of the gut microbiome using metagenomics and metabolomics. The results showed that FBT ameliorated dyslipidemia, hepatic steatosis and steatohepatitis in HFD-induced obese mice by normalizing the gut microbiota structure and tryptophan metabolism. FBT increased the cecal abundance of aryl hydrocarbon receptor (AhR)-ligand producing bacteria such as Lactobacillus_reuteri and Lactobacillus_johnsonii, at the expense of AhR-ligand consuming bacteria, such as Faecalibaculum_rodentium and Escherichia_coli, and elevated the cecal contents of AhR-ligands such as IAA, IPA, and KYNA. Furthermore, FBT regulated the expressions of AhR and its targeted lipometabolic genes such as Pemt, Fasn, and SREBP-1c, as well as other inflammatory genes including TNF-α, IL-6, and IL-1β in the liver of mice. Overall, these findings highlight the beneficial effects of FBT on obesity-related hepatic steatosis and steatohepatitis via microbiota-derived AhR signaling.