Exploring the landscape of steatotic liver disease in the general US population

Genetic correlations between liver fat content, metabolic health, and adiposity distribution in the Fels Longitudinal Study

BACKGROUND AND AIMS

Hepatic steatosis is known to be heritable, but its genetic basis is mostly uncharacterized. Steatosis is associated with metabolic and adiposity features; recent studies hypothesize that shared genetic effects between these traits could account for some of the unexplained heritability. This study aimed to quantify these genetic associations in a family-based sample of non-Hispanic white adults.

METHODS AND RESULTS

704 participants (18-95 years, 55.8% female) from the Fels Longitudinal Study with an MRI assessment of liver fat were included. Quantitative genetic analyses estimated the age- and sex-adjusted heritability of individual traits and the genetic correlations within trait pairs. Mean liver fat was 5.95% (SE = 0.23) and steatosis (liver fat >5.56%) was present in 29.8% of participants. Heritability (h2± SE) of steatosis was 0.72 ± 0.17 (p = 6.80e-6). All other traits including liver enzymes, fasting glucose, HOMA-IR, visceral and subcutaneous adipose tissue (VAT, SAT), body mass index, body fat percent, waist circumference, lipids and blood pressure were also heritable. Significant genetic correlations were found between liver fat and all traits except aspartate aminotransferase (AST), and among most trait pairs. Highest genetic correlations were between liver fat and HOMA-IR (0.85 ± 0.08, p = 1.73e-8), fasting glucose and ALT (0.89 ± 0.26, p = 6.68e-5), and HOMA-IR with: waist circumference (0.81 ± 0.12, p = 3.76e-6), body fat percent (0.78 ± 0.12 p = 2.42e-5) and VAT (0.73 ± 0.07, p = 6.37e-8).

CONCLUSIONS

Common genes may exist between liver fat accumulation, metabolic features and adiposity phenotypes.

Progress is impossible without change: understanding the evolving nomenclature of steatotic liver disease and its effect on hepatology practice

The American, European, and Latin American liver societies have proposed a change in the nomenclature we use to describe alcohol-related liver disease and non-alcoholic fatty liver disease. Additionally, a term encompassing both is now advocated: steatotic liver disease, which includes metabolic dysfunction associated steatotic liver disease (MASLD) and MASLD with greater alcohol consumption (MetALD). These classifications offer increased relevance for clinicians, researchers, and patients alike. In this Viewpoint, we discuss the basis for this nomenclature shift and how it was developed. We also explore the challenges that will be faced in the adoption of such change. The proposed change seeks to banish stigma associated with phrasing such as alcoholic and fatty. However stigma, particularly related to the term fatty, is culturally nuanced, and reflects different entities depending on location. If such a change is internationally accepted, there will be wide-reaching effects on practitioners in primary care and metabolic medicine, and on patients. We discuss those effects and the opportunities the nomenclature change could offer, particularly for patients with alcohol and metabolic risk factors who represent a group previously ignored by clinical trials.

Prevalence of Steatotic Liver Disease (MASLD, MetALD, and ALD) in the United States: NHANES 2017-2020

Following the Delphi consensus process, the term steatotic liver disease (SLD) was introduced to replace fatty liver disease, while the term metabolic dysfunction-associated steatotic liver disease (MASLD) emerged as the successor to the term nonalcoholic fatty liver disease (NAFLD).1 This revised nomenclature aims to enhance precision and mitigate negative connotations and potential stigmatization, while refining comprehension and disease categorization. Concurrently, a novel category was introduced to capture individuals whose alcohol consumption exceeded the previously defined thresholds of NAFLD but remained unclassified within the existing system. This category, termed MetALD, now delineates a spectrum of conditions and is defined as a daily intake of 20 to 50 g of alcohol (or weekly 140-350 g) for females and 30 to 60 g daily for males (or weekly 210-420 g).1 Within the MetALD spectrum, some individuals might predominantly exhibit MASLD characteristics, whereas others might be more inclined toward alcoholic liver disease (ALD).1 In the present study, we used a US nationally representative data set to calculate the prevalence of SLD and its subcategories in the United States.

Liver and atherosclerotic risks of patients with cryptogenic steatotic liver disease

BACKGROUND AND AIMS

In 2023, a new nomenclature of "metabolic associated steatotic liver disease" (MASLD) has emerged by incorporating cardio-metabolic criteria to redefine "non-alcoholic fatty liver disease" (NAFLD). Among steatotic liver disease (SLD), those having no known causes and without any one of cardio-metabolic criteria are deemed to have cryptogenic SLD. This study aims to compare the liver and atherosclerotic risks between MASLD and cryptogenic SLD patients.

APPROACH

We analyzed participants with liver ultrasound data from the Taiwan Bio-Bank cohort, excluding those with positive HBsAg, positive anti-HCV, or "frequent drinker". MASLD involves hepatic steatosis and any of five cardiometabolic risk factors, whereas cryptogenic SLD features hepatic steatosis without these risk factors. Liver fibrosis severity was assessed by using NAFLD fibrosis score (NFS), while atherosclerosis was determined by carotid plaques on duplex ultrasound.

RESULTS

Among 17,595 subjects (age 55.47 ± 10.41; males 31.8%), 7538 participants (42.8%) had SLD, comprising 96.5% of MASLD and 3.5% of cryptogenic SLD. Cryptogenic SLD patients are younger and had a lower percentage of male than those with MASLD. After propensity score matching for age and sex, patients with cryptogenic SLD exhibited milder glucose and lipid profiles, fewer carotid plaques, lower liver steatosis, inflammation, and fibrosis markers than those with MASLD.

CONCLUSIONS

In this large population-based study, cryptogenic SLD, the excluded group, occupy only 3.5% in NAFLD patients. It has lower liver and atherosclerotic risks than MASLD, supporting its exclusion from NAFLD and justifying the rationale for the new disease name and diagnostic criteria of MASLD.

A Population-Based and Clinical Cohort Validation of the Novel Consensus Definition of Metabolic Hyperferritinemia

CONTEXT

There is limited data on the clinical significance of metabolic hyperferritinemia (MHF) based on the most recent consensus.

OBJECTIVE

We aimed to validate the clinical outcomes of MHF in the general population and patients with biopsy-proven metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

The NHANES database and PERSONS cohort were included. MHF was defined as elevated serum ferritin with metabolic dysfunction (MD) and stratified into different grades according to ferritin (grade 1: 200 [females]/300 [males]-550 ng/mL; grade 2: 550-1000 ng/mL; grade 3: >1000 ng/mL). The clinical outcomes, including all-cause death, comorbidities, and liver histology, were compared between non-MHF and MHF in adjusted models.

RESULTS

In NHANES, compared with non-MHF with MD, MHF was related to higher risks of advanced fibrosis (P = .036), elevated albumin-creatinine ratio (UACR, P = .001), and sarcopenia (P = .013). Although the association between all grades of MHF and mortality was insignificant (P = .122), grades 2/3 was associated with increased mortality (P = .029). When comparing with non-MHF without MD, the harmful effects of MHF were more significant in mortality (P < .001), elevated UACR (P < .001), cardiovascular disease (P = .028), and sarcopenia (P < .001). In the PERSONS cohort, MHF was associated with more advanced grades of steatosis (P < .001), lobular inflammation (P < .001), advanced fibrosis (P = .017), and more severe hepatocellular iron deposition (P < .001).

CONCLUSION

Both in the general population and in at-risk individuals with MAFLD, MHF was related with poorer clinical outcomes.

The clinician's view on the advantages and contradictions of the new nomenclature of steatotic liver disease: A review

In September 2023, the European Association for the Study of the Liver (EASL) updated the disease nomenclature for non-alcoholic (metabolically associated) fatty liver disease. The goals of the revision were to increase awareness among health care professionals, civil society and patients about the disease, its course, treatment and outcomes; combating stigma; focusing on the initial etiological factor, including the main (cardiometabolic) risk of disease progression; improved diagnosis based on disease biomarkers; positive impact on the potency to search for new drugs; the ability to provide personalized medical care. The terms “non-alcoholic” and “fatty” were considered stigmatizing, and therefore, it was proposed to use the term steatotic liver disease (SLD) as the name of this nosology. The terms non-alcoholic fatty liver disease (NAFLD) or metabolic associated fatty liver disease (MAFLD) have been replaced by the term metabolic dysfunction-associated steatotic liver disease (MASLD). In the case of being combined with an alcohol factor, a diagnosis in which metabolic dysfunction is combined with alcoholic liver disease is referred to as MetALD. The fundamental principle in the diagnosis of MASLD is the presence of at least one of the cardiometabolic risk factors. Alcohol consumption interacts with cardiometabolic risk factors and increases the risk of SLD decompensation. The term nonalcoholic steatohepatitis (NASH), according to the new nomenclature, has been replaced by the term metabolic dysfunction-associated steatohepatitis (MASH). The adoption of the new nomenclature should help to increase awareness about the disease, its course and outcomes, as well as improve the quality of diagnosis and treatment.

Clinical profiles and mortality rates are similar for metabolic dysfunction-associated steatotic liver disease and non-alcoholic fatty liver disease

BACKGROUND & AIMS

Recently, the term metabolic dysfunction-associated steatotic liver disease (MASLD) has replaced non-alcoholic fatty liver disease (NAFLD). Concern remains regarding whether the evidence generated under the NAFLD definition can be used for MASLD. We compared the clinical profile and outcomes of NAFLD to MASLD using tertiary care- and population-based data.

METHODS

Comparison data were obtained from our NAFLD database and the National Health and Nutrition Examination Survey (NHANES III). Clinical profiles and non-invasive tests (enhanced liver fibrosis [ELF] score, fibrosis-4 index [FIB-4] and vibration-controlled transient elastography) were compared. Mortality data were obtained from NHANES-National Death Index. All-cause mortality was assessed by Cox proportional hazards regression models and cause-specific mortality by competing risk analysis.

RESULTS

There were 6,429 patients in the NAFLD database (age: 54 ± 12 years, 42% male, BMI 35.4 ± 8.3, waist circumference 112 ± 17 cm, 52% type 2 diabetes). Average scores for ELF, FIB-4 and liver stiffness were 9.6 ± 1.2, 1.69 ± 1.24,14.0 ± 11.8 kPa, respectively; 99% met MASLD criteria; 95% met MASLD on BMI only. Predictive accuracy of ELF and FIB-4 were identical between MASLD and NAFLD. We included 12,519 eligible participants from NHANES (age 43.00 years, 47.38% male, 22.70% obese, 7.28% type 2 diabetes, 82.51% ≥1 cardiometabolic criteria). Among the NHANES study population, there was excellent concordance between MASLD and NAFLD diagnoses: Cohen's kappa coefficient: 0.968 (95% CI 0.962-0.973) with 5.29% of NAFLD cases not meeting MASLD criteria. After a median follow-up of 22.83 years, there were no mortality differences between MASLD and NAFLD diagnoses (p values ≥0.05).

CONCLUSIONS

NAFLD and MASLD are similar except individuals with MASLD seem to be older with slightly higher mortality risk, likely owing to cardiometabolic risk factors. Clinical profiles and non-invasive test thresholds were also identical. These data provide evidence that NAFLD and MASLD terminologies can be used interchangeably. For the small proportion of patients with NAFLD who do not meet MASLD criteria, further consideration is needed.

IMPACT AND IMPLICATIONS

In June 2023, new terminology (MASLD) was adopted to replace the term NAFLD as a means to better describe what the liver disease is rather than what it is not, as well as to potentially reduce stigma. Given that MASLD requires at least one cardiometabolic risk factor, questions were raised as to whether this change in the definition would nullify the similarities between NAFLD and MASLD and require new evidence to be generated for MASLD. We used our NAFLD database and a US population-based database to show that the vast majority of patients with NAFLD fulfill criteria for MASLD. Non-invasive tests performed similarly in both groups. Mortality risk was slightly higher in those with MASLD, which is attributed to the presence of cardiometabolic risks. These results provide evidence that data generated in the past three decades for NAFLD can be used interchangeably for MASLD.

Editorial: Crystalising the burden of steatotic liver disease

This article is linked to Schneider et al papers. To view these articles, visit https://doi.org/10.1111/apt.17958 and https://doi.org/10.1111/apt.17992

Association of physical activity with MAFLD/MASLD and LF among adults in NHANES, 2017-2020

OBJECTIVES

To investigate the correlations between physical activity (PA) and metabolic associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD) within a substantial population-based survey, and to examine the association between PA and liver fibrosis (LF).

METHODS

Data from the 2017-2020 NHANES cycle were utilized in this study. PA was divided into four types: leisure-time PA (LTPA), transportation-related PA (TPA), occupational PA (OPA) and total time PA (total PA, which is composed of OPA, TPA and LTPA). Weighted logistic regression models were performed to analyze the associations between PA and MAFLD/MASLD and LF. Mediation analysis was used to explore whether LTPA completely mediated the statistically significant relationship between total PA and MAFLD/MASLD or LF.

RESULTS

The study encompassed a sample size of 5897 participants aged 20 years and above, among the total participants, 2568 individuals with MAFLD and 2588 individuals with MASLD. There was no statistically significant correlation observed between OPA/TPA and MAFLD/MASLD and LF; however, active LTPA demonstrated an inverse association with MAFLD/MASLD (OR: 0.548; 95% CI: 0.458, 0.656/OR: 0.543; 95% CI: 0.453, 0.650), as well as a negative correlation with significant/advanced LF (OR: 0.457; 95% CI: 0.334,0.625/OR: 0.427; 95% CI: 0.295,0.619). There was also a significant inverse association between total PA and MAFLD/MASLD or LF, but this association was carried by the difference in LTPA.

CONCLUSION

Participation in active LTPA is associated with a reduced likelihood of MAFLD/MASLD and LF, while neither OPA nor TPA can replace these effects of LTPA.

Advancements in pharmacological treatment of NAFLD/MASLD: a focus on metabolic and liver-targeted interventions

In the present narrative review, we have summarized evidence on the pharmacological treatment of non-alcoholic fatty liver disease (NAFLD)/metabolic dysfunction-associated steatotic liver disease (MASLD). We start by reviewing the epidemiology of the condition and its close association with obesity and type 2 diabetes. We then discuss how randomized-controlled trials are performed following guidance from regulatory agencies, including differences and similarities between requirements of the US Food and Drug Administration and the European Medicine Agency. Difficulties and hurdles related to limitations of liver biopsy, a large number of screening failures in recruiting patients, as well as unpredictable response rates in the placebo group are evaluated. Finally, we recapitulate the strategies employed for potential drug treatments of this orphan condition. The first is to repurpose drugs that originally targeted T2DM and/or obesity, such as pioglitazone, glucagon-like peptide 1 receptor agonists (liraglutide and semaglutide), multi-agonists (tirzepatide and retatrutide), and sodium-glucose transporter 2 inhibitors. The second is to develop drugs specifically targeting NAFLD/MASLD. Among those, we focused on resmetirom, fibroblast growth factor 21 analogs, and lanifibranor, as they are currently in Phase 3 of their clinical trial development. While many failures have characterized the field of pharmacological treatment of NAFLD/MASLD in the past, it is likely that approval of the first treatments is near. As occurs in many chronic conditions, combination therapy might lead to better outcomes. In the case of non-alcoholic steatohepatitis, we speculate that drugs treating underlying metabolic co-morbidities might play a bigger role in the earlier stages of disease, while liver-targeting molecules will become vital in patients with more advanced disease in terms of inflammation and fibrosis.

Noninvasive tests maintain high accuracy for advanced fibrosis in chronic hepatitis B patients with different nomenclatures of steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a new nomenclature proposed in 2023. We aimed to compare the diagnostic efficacy of noninvasive tests (NITs) for advanced fibrosis under different nomenclatures in patients with chronic hepatitis B (CHB). A total of 844 patients diagnosed with CHB and concurrent steatotic liver disease (SLD) by liver biopsy were retrospectively enrolled and divided into four groups. The performances of fibrosis-4 (FIB-4), gamma-glutamyl transpeptidase to platelet ratio index (GPRI), aspartate aminotransferase to platelet ratio index (APRI), and liver stiffness measurement (LSM) were compared among the four groups. The four NITs showed similar diagnostic efficacy for nonalcoholic fatty liver disease (NAFLD), MASLD, and metabolic dysfunction-associated fatty liver disease (MAFLD) in patients with CHB with advanced fibrosis. LSM showed the most stable accuracy for NAFLD (AUC = 0.842), MASLD (AUC = 0.846), and MAFLD (AUC = 0.863) compared with other NITs (p < 0.05). Among the four NITs, APRI (AUC = 0.841) and GPRI (AUC = 0.844) performed best in patients with CHB & MetALD (p < 0.05). The cutoff value for GPRI in patients with CHB & MetALD was higher than that in the other three groups, while further comparisons of NITs at different fibrosis stages showed that the median GPRI of CHB & MetALD (1.113) at F3-4 was higher than that in the CHB & MASLD group (0.508) (p < 0.05). Current NITs perform adequately in patients with CHB and SLD; however, alterations in cutoff values for CHB & MetALD need to be noted.

Liver fibrosis, NT-ProBNP and mortality in patients with MASLD: A population-based cohort study

BACKGROUND & AIM

Liver fibrosis is the strongest predictor of liver-related mortality in many chronic liver diseases. NT-ProBNP is independently associated with cardiovascular mortality in general population settings. Here, we evaluate the relative contribution of non-invasively identified liver fibrosis and NT-ProBNP on all-cause and cardiovascular mortality in patients with metabolic (dysfunction)-associated steatotic liver disease (MASLD).

METHODS AND RESULTS

Serum NT-ProBNP levels were measured in 4229 patients with MASLD from the general population without a known history of heart failure that participated in the 1999-2004 cycles of the National Health and Nutrition Examination Survey. Presence of liver fibrosis was estimated using the Fibrosis-4 index (FIB-4). We applied Cox proportional hazard models adjusted for cardiovascular risk factors to evaluate the association between NT-ProBNP and FIB-4 levels and all-cause and cardiovascular mortality through December 2019. Mortality was lower for participants with normal levels of both biomarkers, intermediate if a single biomarker was elevated and highest when both were above the chosen threshold. In the multivariable-adjusted models, both elevated FIB-4 (≥2.67) and elevated NT-ProBNP levels (≥125 pg/ml) were independently associated with higher risks of all-cause mortality (HR 2.2, 95 % CI 1.5-3.2 and HR 1.6, 95 % CI 1.4-2.0, respectively) and cardiovascular mortality (HR 2.1, 95 % CI 1.2-3.7 and HR 2.1, 95 % CI 1.5-2.9, respectively). The associations remained consistent in subgroup analyses based on sex, obesity and age.

CONCLUSIONS

Both FIB-4 and NT-ProBNP are independently associated with higher mortality in patients with MASLD. Their combined use might prove useful to risk-stratify patients in clinical practice.

Association between metabolic dysfunction-associated steatotic liver disease and risk of incident pancreatic cancer: a systematic review and meta-analysis of cohort studies

Background and objectives

Since the results of previous observational studies on the relationship between metabolic dysfunction-associated steatotic liver disease (MASLD) and pancreatic cancer were still controversial and inconsistent, we performed a systematic evaluation and meta-analysis of cohort studies to assess any potential association.

Methods

We conducted a systematic search of PubMed, Embase, and Web of Science databases from the database's inception up to November 30, 2023. For summary purposes, hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using random-effects models, and subgroup and sensitivity analyses were performed as well. The Egger's test and Begg's test were utilized to detect the publication bias.

Results

This meta-analysis included nine cohort studies with a total of 10,428,926 participants. The meta-analysis demonstrated an increased risk of pancreatic cancer in those with MASLD (HR = 1.32, 95% CI: 1.10-1.59, P = 0.003) with moderate heterogeneity (I2 = 54%, P = 0.03). Subsequent subgroup analyses revealed that the pooled HRs remained significantly unchanged, irrespective of the study area, nomenclature of fatty liver disease, and sample size. The results of the sensitivity analyses remained unchanged. No evidence of publication bias was found.

Conclusion

This meta-analysis indicated that MASLD was associated with a higher risk of pancreatic cancer. To further strengthen the association, future prospective cohort studies should take into account different ethnic groups, diagnostic methods of fatty liver, the severity of MASLD, and potential confounding factors, as well as explore the potential mechanisms of pancreatic cancer development in MASLD patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42023489137.

Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race

OBJECTIVE

The objective of this study was to assess the performance of noninvasive tests (NITs) across different racial and ethnic groups in a large multiethnic cohort.

METHODS

Data were derived from the National Health and Nutrition Examination Survey (NHANES) 2017 through 2020. Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study.

RESULTS

Among the 6359 adults included in the study, fatty liver index and nonalcoholic fatty liver disease liver fat scores performed well for the prediction of metabolic dysfunction-associated steatotic liver disease, without significant changes across racial and ethnic groups. However, significant differences were observed across racial and ethnic groups for the prediction of advanced fibrosis and cirrhosis. The fibrosis-4 (FIB-4) index, aspartate aminotransferase to platelet ratio index (APRI), and nonalcoholic fatty liver disease fibrosis score underperformed in non-Hispanic Black patients for the detection of cirrhosis. For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI. Using a cutoff point of 12 kPa for advanced fibrosis, both APRI and the FIB-4 index performed significantly worse in non-Hispanic Black patients.

CONCLUSIONS

In a large, diverse national cohort, the performance of NITs was overall poor compared with transient elastography, and NITs showed differences across racial and ethnic groups. Given the widespread use of NITs, it is imperative that the scores are equitable across racial and ethnic groups.

Prevalence of Steatotic Liver Disease Among US Adults with Rheumatoid Arthritis

BACKGROUND

The prevalence of steatotic liver disease (SLD) among patients with rheumatoid arthritis (RA) remains largely unknown.

AIMS

To investigate the prevalence of SLD and liver fibrosis among patients with RA.

METHODS

We utilized data from the United States (US)-based National Health and Nutrition Examination Survey (NHANES) 2017-2020 cycle. After applying established sample weights, we estimated the age-adjusted prevalence of SLD and its subclassifications (CAP ≥ 285 dB/m), high-risk NASH (FAST score) and liver fibrosis (LSM) among participants with self-reported RA. Multivariable logistic regression was performed to identify independent risk factors for metabolic dysfunction associated SLD (MASLD), high-risk NASH and fibrosis, respectively, among participants with RA. We present adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

Age-adjusted prevalence of MASLD among US adults with RA was 34.91% (95% CI: 24.02-47.65%). We also found that the age-adjusted prevalence of high-risk NASH (FAST score > 0.35) and significant fibrosis (LSM > 8.6 kPa) was 12.97% (95% CI: 6.89-23.07%) and 10.35% (95% CI: 5.55-18.48%), respectively. BMI ≥ 30 kg/m2, (aOR 6.23; 95% CI: 1.95-19.88), diabetes (aOR 5.90; 95% CI: 1.94-17.94), and dyslipidemia (aOR 2.83; 95% CI: 1.12-7.11) were independently associated with higher odds of MASLD among participants with RA. Diabetes (aOR 19.34; 95% CI: 4.69-79.70) was also independently associated with high-risk NASH.

CONCLUSIONS

The prevalence of MASLD, high-risk NASH, and liver fibrosis among patients with RA is equal or higher than the general population. Future studies of large cohorts are needed to substantiate the role of systemic inflammation in the pathophysiology of MASLD.

Association between TyG index trajectory and new-onset lean NAFLD: a longitudinal study

OBJECTIVE

The purpose of this manuscript is to identify longitudinal trajectories of changes in triglyceride glucose (TyG) index and investigate the association of TyG index trajectories with risk of lean nonalcoholic fatty liver disease (NAFLD).

METHODS

Using data from 1,109 participants in the Health Management Cohort longitudinal study, we used Latent Class Growth Modeling (LCGM) to develop TyG index trajectories. Using a Cox proportional hazard model, the relationship between TyG index trajectories and incident lean NAFLD was analyzed. Restricted cubic splines (RCS) were used to visually display the dose-response association between TyG index and lean NAFLD. We also deployed machine learning (ML) via Light Gradient Boosting Machine (LightGBM) to predict lean NAFLD, validated by receiver operating characteristic curves (ROCs). The LightGBM model was used to create an online tool for medical use. In addition, NAFLD was assessed by abdominal ultrasound after excluding other liver fat causes.

RESULTS

The median age of the population was 46.6 years, and 440 (39.68%) of the participants were men. Three distinct TyG index trajectories were identified: "low stable" (TyG index ranged from 7.66 to 7.71, n=206, 18.5%), "moderate stable" (TyG index ranged from 8.11 to 8.15, n=542, 48.8%), and "high stable" (TyG index ranged from 8.61 to 8.67, n=363, 32.7%). Using a "low stable" trajectory as a reference, a "high stable" trajectory was associated with an increased risk of lean-NAFLD (HR: 2.668, 95% CI: 1.098-6.484). After adjusting for baseline age, WC, SBP, BMI, and ALT, HR increased slightly in "moderate stable" and "high stable" trajectories to 1.767 (95% CI:0.730-4.275) and 2.668 (95% CI:1.098-6.484), respectively. RCS analysis showed a significant nonlinear dose-response relationship between TyG index and lean NAFLD risk (χ2 = 11.5, P=0.003). The LightGBM model demonstrated high accuracy (Train AUC 0.870, Test AUC 0.766). An online tool based on our model was developed to assist clinicians in assessing lean NAFLD risk.

CONCLUSION

The TyG index serves as a promising noninvasive marker for lean NAFLD, with significant implications for clinical practice and public health policy.

Prevalence of Steatotic Liver Disease Based on a New Nomenclature in the Japanese Population: A Health Checkup-Based Cross-Sectional Study

This cross-sectional study examined the prevalence and characteristics of steatotic liver disease (SLD) based on a recently introduced nomenclature in the Japanese health checkup population. SLD was evaluated using liver ultrasonography, and participants were categorized into metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol associated steatotic liver disease (MetALD), alcohol-associated/related liver disease (ALD), and cryptogenic SLD groups. The prevalence and characteristics of the SLD subclasses were assessed, and subgroup analyses were conducted for the non-obese (body mass index [BMI] ≤ 25 kg/m2) and lean (BMI ≤ 23 kg/m2) populations. Among the 694 participants, with a median age of 47 years and comprising 54% males, the prevalence of MASLD, MetALD, ALD, and cryptogenic SLD was 26%, 2%, 1%, and 2%, respectively. A remarkable difference was observed in the prevalence of SLD subclasses according to age, sex, and BMI. Subgroup analyses revealed heterogeneous demographic, clinical, and biochemical parameters between the SLD categories. Individuals with MetALD had higher gamma-glutamyl transferase levels, lower platelet counts, and higher fibrosis-4 index than did those with MASLD. Furthermore, the prevalence of non-obese and lean MASLD was 13% and 6%, respectively. This study provides preliminary information on the prevalence of SLD based on a new nomenclature in the Japanese population.

Making Sense of the Nonalcoholic Fatty Liver Disease Clinical Practice Guidelines: What Clinicians Need to Know

Standards of care summarized in clinical practice guidelines for nonalcoholic fatty liver disease (NAFLD) offer clinicians a streamlined diagnostic and management approach based on the best available evidence. These recommendations have changed a great deal in recent years; today, there is a clear focus on screening for the early identification and risk stratification of patients at high risk of steatohepatitis and clinically significant fibrosis to promote timely referrals to specialty care when needed. This article reviews and provides the rationale for current guidelines for NAFLD screening, diagnosis, treatment, and monitoring and addresses barriers to providing evidence-based NAFLD care and how to overcome them. The current paradigm of care calls for primary care clinicians and specialists to work together, within a multidisciplinary care team familiar with obesity and diabetes care, to provide comprehensive management of these complex patients.

Metabolic dysfunction-associated steatotic liver disease increases hepatocellular carcinoma risk in chronic hepatitis B patients: a retrospective cohort study

Background: The combined effect of hepatitis B virus infection and metabolic dysfunction-associated steatotic liver disease (MASLD) on hepatocellular carcinoma (HCC) risk remains unclear. The current study sought to elucidate the impact of MASLD on HCC progression in chronic hepatitis B (CHB) patients. Method: This retrospective cohort study included CHB patients who had undergone liver biopsy and abdominal imaging at the Guangdong Provincial Hospital of Chinese Medicine between 2013 and 2019. We investigated the correlation between MASLD and HCC risk, and inverse probability treatment weighting (IPTW) was used to adjust for patient characteristics. Results: A total of 1,613 patients were included, and 483 (29.9%) were diagnosed with MASLD. Over a median follow-up period of 5.02 years, 36 (2.2%) developed HCC, comprising 4.8% (23/483) of those with MASLD and 1.2% (13/1,130) of those without. Those with MASLD had a significantly higher cumulative incidence of HCC than those without (p < 0.001). The presence of MASLD was associated with a higher risk of HCC (adjusted hazard ratio [HR], 3.996; 95% confidence interval [CI], 2.007-7.959; p < 0.001). After adjustment using IPTW, the patients with MASLD retained a higher cumulative incidence of HCC (p < 0.001). Moreover, MASLD was found to be an independent risk factor for the development of HCC (adjusted HR, 10.191; 95% CI, 4.327-24.002; p < 0.001). However, among patients with MASLD, there were no significant differences in the cumulative risk of HCC between patients with and without overweight, between those with <2 and ≥2 cardiometabolic risk factors (CMRFs), between those with <3 and ≥3 CMRFs, or between those with <4 and ≥4 CMRFs (p = 0.110, p = 0.087, p = 0.066, and p = 0.490, respectively). Conclusion: The presence of MASLD is associated with a higher risk of HCC in patients with CHB. Notably, this higher risk is present in patients with MASLD, irrespective of the presence or absence of overweight or the number of CMRFs they have.

Complementary role of peripheral and central autonomic nervous system on insulin-like growth factor-1 activation to prevent fatty liver disease

BACKGROUND

Insulin-like growth factor-1 (IGF-1) is involved in the pathology of non-alcoholic fatty liver disease (NAFLD) and ameliorates fatty infiltration in the liver. It is activated by growth hormone (GH); however, the role of GH-IGF-1 axis in NAFLD developmental phase has not been well identified. Therefore, in this study, we focused on the effect of IGF-1 in NAFLD pathology and GH excretion activation from the pituitary gland by peripheral autonomic neural pathways relaying liver-brain-gut pathway and by central neuropeptides.

METHODS

GH and IGF-1 levels were assessed in wild-type and melanocortin-4 receptor knockout mice upon the development of diet-induced NAFLD. The contribution of the peripheral autonomic nervous system connecting the liver-brain-gut axis was assessed by its blockade using capsaicin and that of the central nervous system was assessed by the expression of hypothalamic brain-derived neurotrophic factor (BDNF) and corticotropin-releasing factor (CRH), which activates GH release from the pituitary gland.

RESULTS

In the NAFLD mouse models, the levels of GH and IGF-1 increased (p < .05). Further, hepatic fatty infiltration was suppressed even under peripheral autonomic nervous system blockade (p < .001), which inhibited gastric ghrelin expression. In mice with peripheral autonomic nervous blockade, hypothalamic BDNF and CRH were inhibited (p < .05), resulting in GH and IGF-1 excretion, whereas other neuropeptides of somatostatin and cortistatin showed no changes. These complementary effects were canceled in melanocortin-4 receptor knockout mice, which diminished BDNF and CRH release control.

CONCLUSIONS

Our study demonstrates that the release of IGF-1 by the nervous system is a key factor in maintaining the pathological homeostasis of NAFLD, suggesting its therapeutic potential.

New Nomenclature for Nonalcoholic Fatty Liver Disease: Understanding Metabolic Dysfunction-Associated Steatotic Liver Disease, Metabolic Dysfunction- and Alcohol-Associated Liver Disease, and Their Implications in Clinical Practice

In June 2023, under the patronage of the American Association for Study of Liver Disease, the European Association for Study of the Liver, and the Asociación Latinoamericana para el Estudio del Hígado with the involvement of 236 participants from around the world, a new nomenclature and definition for nonalcoholic fatty liver disease (NAFLD) has been proposed. Metabolic dysfunction-associated steatotic liver disease (MASLD) was defined as presence of hepatic steatosis and at least one of the cardiometabolic risk factors with alcohol intake less than 140 g/wk for women and 210 g/wk for men and no other causes of steatosis. A new entity called combined metabolic dysfunction- and alcohol-associated liver disease (MetALD) was created outside of pure MASLD for patients with metabolic dysfunction and alcohol intake greater than that allowed for MASLD (i.e., 140-350 g/wk for women and 210-420 g/wk for men). Recent studies have confirmed a 95% overlap between NAFLD and the new MASLD diagnostic criteria. Natural history, biomarkers, and thresholds of alcohol intake in MetALD group remains to be studied and validated.

Non-alcoholic fatty liver disease increases the risk of cardiovascular disease in young adults and children: a systematic review and meta-analysis of cohort studies

Background and aims

It is uncertain if there is a link between non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVD) in young adults and children. To evaluate the potential link between these two conditions, we conducted a systematic review and meta-analysis of cohort studies.

Methods

A comprehensive search was conducted in PubMed, Web of Science and Embase in order to locate all relevant cohort studies published until August 2023. Random effects meta-analyses were conducted using the generic inverse variance method, with additional subgroup and sensitivity analyses. The Newcastle-Ottawa Scale was employed to evaluate the methodological quality.

Results

Four cohort studies (eleven datasets) involving 10,668,189 participants were included in this meta-analysis. This meta-analysis demonstrated that NAFLD increases the risk of CVD in young adults and children (HR = 1.63, 95% CI: 1.46-1.82, P < 0.00001). Further subgroup analyses showed that individuals with NAFLD were at a heightened risk of coronary heart disease (CHD) (HR = 3.10, 95% CI: 2.01-4.77, P < 0.00001), myocardial infarction (MI) (HR = 1.69, 95% CI: 1.61-1.78, P < 0.00001), atrial fibrillation (AF) (HR = 2.00, 95% CI: 1.12-3.57, P = 0.02), congestive heart failure (CHF) (HR = 3.89, 95% CI: 1.20-12.61, P = 0.02), and stroke (HR = 1.47, 95% CI: 1.39-1.55, P < 0.00001). The results of subgroup analyses based on the study location, NAFLD definition, and follow-up time also showed consistency with the overall results. Sensitivity analyses showed that our results were robust. All of the included studies were judged to be of medium to high quality.

Conclusion

Current evidence reveals that NAFLD is linked to an increased risk of major CVD (including CHD, MI, AF, CHF and stroke) in young adults and children. Further research is needed to strengthen this association and provide stronger evidence for primary prevention of CVD in young adults and children with NAFLD.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, PROSPERO registration number: CRD42023457817.

Steatotic liver disease, MASLD and risk of chronic kidney disease

With the rising tide of fatty liver disease related to metabolic dysfunction worldwide, the association of this common liver disease with chronic kidney disease (CKD) has become increasingly evident. In 2020, the more inclusive term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed to replace the old term non-alcoholic fatty liver disease (NAFLD). In 2023, a modified Delphi process was led by three large pan-national liver associations. There was consensus to change the fatty liver disease nomenclature and definition to include the presence of at least one of five common cardiometabolic risk factors as diagnostic criteria. The name chosen to replace NAFLD was metabolic dysfunction-associated steatotic liver disease (MASLD). The change of nomenclature from NAFLD to MAFLD and then MASLD has resulted in a reappraisal of the epidemiological trends and associations with the risk of developing CKD. The observed association between MAFLD/MASLD and CKD and our understanding that CKD can be an epiphenomenon linked to underlying metabolic dysfunction support the notion that individuals with MASLD are at substantially higher risk of incident CKD than those without MASLD. This narrative review provides an overview of the literature on (a) the evolution of criteria for diagnosing this highly prevalent metabolic liver disease, (b) the epidemiological evidence linking MASLD to the risk of CKD, (c) the underlying mechanisms by which MASLD (and factors strongly linked with MASLD) may increase the risk of developing CKD, and (d) the potential drug treatments that may benefit both MASLD and CKD.

Causal effects of non-alcoholic fatty liver disease on osteoporosis: a Mendelian randomization study

Background

Osteoporosis (OP) is a systemic skeletal disease characterized by compromised bone strength leading to an increased risk of fracture. There is an ongoing debate on whether non-alcoholic fatty liver disease (NAFLD) is an active contributor or an innocent bystander in the pathogenesis of OP. The aim of this study was to assess the causal association between NAFLD and OP.

Methods

We performed two-sample Mendelian randomization (MR) analyses to investigate the causal association between genetically predicted NAFLD [i.e., imaging-based liver fat content (LFC), chronically elevated serum alanine aminotransferase (cALT) and biopsy-confirmed NAFLD] and risk of OP. The inverse variant weighted method was performed as main analysis to obtain the causal estimates.

Results

Imaging-based LFC and biopsy-confirmed NAFLD demonstrated a suggestive causal association with OP ([odds ratio (OR): 1.003, 95% CI: 1.001-1.004, P < 0.001; OR: 1.001, 95% CI: 1.000-1.002, P = 0.031]). The association between cALT and OP showed a similar direction, but was not statistically significant (OR: 1.001, 95% CI: 1.000-1.002, P = 0.079). Repeated analyses after exclusion of genes associated with confounding factors showed consistent results. Sensitivity analysis indicated low heterogeneity, high reliability and low pleiotropy of the causal estimates.

Conclusion

The two-sample MR analyses suggest a causal association between genetically predicted NAFLD and OP.

MASLD treatment-a shift in the paradigm is imminent

MASLD prevalence is growing towards the leading cause of end-stage liver disease. Up to today, the most effective treatment is weight loss. Weight loss interventions are moving from lifestyle changes to bariatric surgery or endoscopy, and, more recently, to a new wave of anti-obesity drugs that can compete with bariatric surgery. Liver-targeted therapy is a necessity for those patients who already present liver fibrosis. The field is moving fast, and in the near future, we will testify to a disruptive change in MASLD treatment, similar to the paradigm-shift that occurred for hepatitis C almost one decade ago with direct antiviral agents.

Associations of metabolic dysfunction-associated fatty liver disease and hepatic fibrosis with bone mineral density and risk of osteopenia/osteoporosis in T2DM patients

Background

Existing evidence on the associations of liver steatosis and fibrosis with bone mineral density (BMD) and risk of osteopenia/osteoporosis was limited with conflicting results. We aimed to evaluate the associations of metabolic dysfunction-associated fatty liver disease (MAFLD) and hepatic fibrosis with BMD and risk of osteopenia/osteoporosis in type 2 diabetes mellitus (T2DM) patients.

Methods

Baseline information of an ongoing cohort of 249 T2DM patients in Xiamen, China was analyzed. MAFLD was defined as the presence of hepatic steatosis [diagnosed by either hepatic ultrasonography scanning or fatty liver index (FLI) score >60] for T2DM patients. BMD was measured using dual-energy x-ray absorptiometry at total lumbar (L2-4), femur neck (FN), and total hip (TH) and was categorized as normal (T ≥ -1.0), osteopenia (-2.5 < T < -1.0), or osteoporosis (T ≤ -2.5) according to its minimum T-score.

Results

Among the 249 T2DM patients, prevalence rates of MAFLD, osteopenia, and osteoporosis were 57.8%, 50.6%, and 17.7%, respectively. Patients with MAFLD had significantly higher BMD T-scores of L2-4, FN, and TH and the minimum as well as lower prevalence of osteoporosis than patients without MAFLD. Hepatic steatosis indices, including FLI score, fatty liver (FLI ≥ 60 or hepatic ultrasonography scanning), and MAFLD, were significantly and positively associated with all T-scores, while hepatic fibrosis index and FIB-4 score, but not NAFLD fibrosis score (NFS), were negatively associated with all T-scores. MAFLD was significantly associated with the decreased risk of osteopenia/osteoporosis and osteoporosis with unadjusted odds ratios (ORs) (95% CI) of 0.565 (0.324-0.987) and 0.434 (0.224-0.843) (both p-values < 0.05), respectively. As for liver fibrosis, FIB-4 score, but not NFS, was significantly associated with elevated risk of osteoporosis with an unadjusted OR (95% CI) per SD increase of FIB-4 score of 1.446 (1.080-1.936, p-value = 0.013). Adjusting for potential confounding variables, especially body mass index, in the multivariable regression analyses, all associations of hepatic steatosis and fibrosis indices with BMD and risk of osteopenia/osteoporosis were not statistically significant.

Conclusion

MAFLD and hepatic fibrosis were not significantly associated with BMD and risk of osteopenia/osteoporosis independent of obesity. Nevertheless, screening and management of MAFLD and osteopenia/osteoporosis were still important for the prevention of fracture in T2DM patients.

Prognostic models and autoimmune liver diseases

Autoimmune liver diseases (AILDs) are complex diseases with unknown causes and immune-mediated pathophysiology. In primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) disease modifying drugs are available which improve patient quality and quantity of life. In primary sclerosing cholangitis (PSC) no medical therapy is available and the only accepted treatment is liver transplantation (LT). PBC, PSC and AIH possess features that describe the archetype of patients within each disorder. On the other hand, the classical disorders are not homogeneous, and patients within each diagnosis may present with a range of clinical, biochemical, serological, and histological findings. Singularly, they are considered rare diseases, but together, they account for approximately 20% of LTs in Europe and USA. Management of these patients is complex, as AILDs are relatively uncommon in clinical practice with challenges in developing expertise, disease presentation can be sneaky, clinical phenotypes and disease course are heterogeneous. Prognostic models are key tools for clinicians to assess patients' risk and to provide personalized care to patients. Aim of this review is to discuss challenges of the management of AILDs and how the available prognostic models can help. We will discuss the prognostic models developed in AILDs, with a special focus on the prognostic models that can support the clinical management of patients with AILDs: in PBC models based on ursodeoxycholic acid (UDCA) response and markers of liver fibrosis; in PSC several markers including biochemistry, disease stage and radiological semiquantitative markers; and finally in AIH, markers of disease stage and disease activity.

The relationship between skeletal muscle mass to visceral fat area ratio and metabolic dysfunction-associated fatty liver disease subtypes in middle-aged and elderly population: a single-center retrospective study

Background

It has been reported that decreased muscle mass combined with excessive visceral adipose tissue are significantly correlated with the risk of non-alcoholic fatty liver disease (NAFLD). However, it has not been explored among populations with metabolic dysfunction-associated fatty liver disease (MAFLD) subtypes. We aimed to investigate whether appendicular skeletal muscle mass to visceral fat area ratio (SVR), an indicator of sarcopenic obesity, influences on the risk of MAFLD subtypes and its hepatic condition in middle-aged and elderly population.

Methods

A total of 4,003 middle-aged and elderly subjects were finally enrolled in this single-center retrospective study. Abdominal ultrasonography was employed for hepatic steatosis diagnosis. Participants were divided into four groups: diabetes-MAFLD, overweight/obese-MAFLD, lean-MAFLD and no MAFLD. Appendicular skeletal muscle mass as well as visceral fat area (VAF) was estimated by bioimpedance analysis measurements. Liver fibrosis was defined as a Fibrosis-4 index (FIB-4) and the NAFLD Fibrosis Score (NFS). Multivariate logistic regression analysis was performed to estimate the odds ratio and 95% confidence interval between SVR and MAFLD subtypes/hepatic condition stratified by sex.

Results

Participants with MAFLD subtypes had a significant lower value of SVR compared with those without MAFLD (P<0.001), while high quartiles of FIB-4 and NFS also showed a decreasing value of SVR in comparison with its lower quartiles (Pfor trend<0.001). The lowest quartile of SVR increased the prevalence of MAFLD subtypes [adjusted OR (95%CI): 2.96 (1.48 ~ 5.93) male /3.30(1.46 ~ 7.46) female for diabetes-MAFLD, 1.91(1.26 ~ 2.88) male /4.48(1.91 ~ 10.49) female for overweight/obese-MAFLD and 4.01(1.46 ~ 10.98) male/2.53(1.19 ~ 5.37) female for lean-MAFLD groups] compared with the highest quartile of SVR (all Pfor trend<0.001). Besides, the interaction effect of gender on the relationship between SVR and MAFLD subtypes was statistically significant (all Pfor interaction<0.001).Restricted cubic spline indicated an inverse association between SVR and the risk of MAFLD subtypes with linearity (all P for non-linearity>0.05). The lowest quartile of SVR also increases the risk of MAFLD fibrosis in both males and females.

Conclusion

Our study concluded that a decrease in SVR (appendicular skeletal muscle mass divided by visceral fat area) is significantly associated with an increased prevalence of developing MAFLD subtypes and liver fibrosis in middle-aged and older persons of both genders.