Geographical similarity and differences in the burden and genetic predisposition of NAFLD

Association of sex-specific body mass index and waist circumference trajectories with non-alcoholic fatty liver disease incidence based on growth mixture modeling

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease. The relationship between the trajectories of obesity indicators and incident NAFLD is unknown. Therefore, this study aims to explore the sex-specific association between the trajectories of obesity indicators and the incidence of NAFLD.

METHODS AND RESULTS

In total, 9067 participants were recruited for this longitudinal study. Obesity indicators use body mass index (BMI) and waist circumference (WC). The trajectory of obesity indicators was analyzed using the growth mixture modeling. The multivariate logistic regression model was used to analyze the association between obesity indicators' trajectories and incident NAFLD. Over a median follow-up of 1.82 years, 1013 (11.74%) participants developed NAFLD. We identified BMI and WC change trajectories as the stable group, increasing group, and decreasing group. After adjusting for baseline level and other confounders, multivariate logistic regression analysis showed that compared with stable group of BMI, the increasing group, and decreasing group odds ratio and 95% confidence interval of NAFLD were 2.10 (1.06-4.15), and 0.25 (0.09-0.67) in men, and 1.82 (1.08-3.04) and 0.32 (0.16-0.64) in women. Compared with stable group of WC, the increasing group was 2.57 (1.39-4.74) in men, the increasing group, and decreasing group were 2.29 (1.70-3.10) and 0.28 (0.12-0.64) in women. Sensitivity analysis showed that the results were stable.

CONCLUSION

The BMI and WC changing trajectories are significantly associated with the incidence of NAFLD in men and women. Populations of real-world health examinations can be categorized based on obesity indicator changes to prevent NAFLD.

Natural history of lean and non-lean metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Conflicting evidence regarding the prognosis of lean metabolic dysfunction-associated steatotic liver disease (MASLD) has raised substantial questions.

AIM

This study aimed to elucidate the prognosis of lean MASLD by conducting a comprehensive analysis of a vast Asian cohort.

METHODS

This study used a nationwide, population-based database and analyzed 2.9 million patients. The primary endpoints were liver-related events (LREs) and cardiovascular events (CVEs) in patients with lean MASLD, non-lean MASLD, and normal liver control groups.

RESULTS

The median observation period was 4.2 years. The 5-year incidence values of LREs in the lean MASLD, non-lean MASLD, and normal liver control groups were 0.065%, 0.039%, and 0.006%, respectively. The LRE risk of lean MASLD was significantly higher than that of normal liver control (adjusted hazard ratio [aHR]: 5.94, 95% confidence interval [CI]: 3.95-8.92) but comparable to that of non-lean MASLD (aHR: 1.35, 95% CI: 0.87-2.08). By contrast, for CVEs, the non-lean MASLD group exhibited a higher 5-year cumulative incidence rate (0.779%) than the lean MASLD (0.600%) and normal liver control (0.254%) groups. The lean MASLD group had a reduced risk of CVEs compared with the non-lean MASLD group (aHR, 0.73; 95% CI: 0.64-0.84), and comparable risk of CVEs to the normal liver control group (aHR, 0.99; 95% CI: 0.88-1.12).

CONCLUSION

Lean MASLD exhibits a similar LRE risk and a lower CVE risk to non-lean MASLD. Therefore, follow-up and treatment strategies should be tailored to the specific MASLD condition.

Risk of liver-related events in metabolic dysfunction-associated steatohepatitis (MASH) patients with fibrosis: A comparative analysis of various risk stratification criteria

BACKGROUND AND AIMS

International regulatory agencies recommend testing drug therapy for patients with noncirrhotic high-risk metabolic dysfunction-associated steatohepatitis (MASH) because they are at risk of liver-related events (LRE). We aimed to compare the risk of LRE in patients with MASLD stratified for F2-F4 fibrosis and MASH.

APPROACH AND RESULTS

Overall, 1938 consecutive patients with biopsy-proven MASLD were enrolled. High-risk MASH was defined as MASH with F2-F4 fibrosis. LSM was measured by transient elastography. LRE were recorded during follow-up. Cox multivariate models were used to assess the association between high-risk MASH or F2-F4 fibrosis without MASH, of LSM (≥8 or ≥10 Kpa), and of AGILE 3+ with LRE. The diagnostic performance for the prediction of LRE was assessed using the area under the receiver operating characteristic curves. The observed 5-year actuarial rate of LRE was 0.4%, 0.2%, 5.1%, and 6.6% in patients with F0-F1 fibrosis without MASH, F0-F1 fibrosis with MASH, F2-F4 fibrosis without MASH, and high-risk MASH, respectively. At multivariate Cox regression analysis using F0-F1 fibrosis without MASH as a reference, both F2-F4 fibrosis without MASH [adjusted HR (aHR) 9.96] and high-risk MASH (aHR 10.14) were associated with LRE. In the 1074 patients with available LSM, LSM ≥ 10 kPa (aHR 6.31) or AGILE 3+ > 0.67 (aHR 27.45) independently predicted the development of LRE and had similarly acceptable 5-year area under the receiver operating characteristic to high-risk MASH and F2-F4 fibrosis (0.772, 0.818, 0.739, and 0.780, respectively).

CONCLUSIONS

The risk of LRE is similar in patients with high-risk MASH and with F2-F4 fibrosis without MASH. The use of LSM ≥ 10 kPa or AGILE 3+ > 0.67 could be an accurate option to identify patients with MASLD worthy to be included in clinical trials.

Alcohol Drinking Impacts on Adiposity and Steatotic Liver Disease: Concurrent Effects on Metabolic Pathways and Cardiovascular Risks

PURPOSE OF REVIEW

This integrative search aimed to provide a scoping overview of the relationships between the benefits and harms of alcohol drinking with cardiovascular events as associated to body fat mass and fatty liver diseases, as well as offering critical insights for precision nutrition research and personalized medicine implementation concerning cardiovascular risk management associated to ethanol consumption.

RECENT FINDINGS

Frequent alcohol intake could contribute to a sustained rise in adiposity over time. Body fat distribution patterns (abdominal/gluteus-femoral) and intrahepatic accumulation of lipids have been linked to adverse cardiovascular clinical outcomes depending on ethanol intake. Therefore, there is a need to understand the complex interplay between alcohol consumption, adipose store distribution, metabolic dysfunction-associated steatotic liver disease (MASLD), and cardiovascular events in adult individuals. The current narrative review deals with underconsidered and apparently conflicting benefits concerning the amount of alcohol intake, ranging from abstention to moderation, and highlights the requirements for additional robust methodological studies and trials to interpret undertrained and existing controversies. The conclusion of this review emphasizes the need of newer multifaceted clinical approaches for precision medicine implementation, considering epidemiological strategies and pathophysiological mechanistic. Newer investigations and trials should be derived and performed particularly focusing both on alcohol's objective consequences as putatively mediated by fat deposition, including associated roles in fatty liver disease as well as to differentiate the impact of different levels of alcohol consumption (absence or moderation) concerning cardiovascular risks and accompanying clinical manifestations. Indeed, the threshold for the safe consumption of alcoholic drinks remains to be fully elucidated.

Cross talk between the liver microbiome and epigenome in patients with metabolic dysfunction-associated steatotic liver disease

BACKGROUND

The pathogenesis of MASLD (metabolic dysfunction-associated steatotic liver disease), including its severe clinical forms, involves complex processes at all levels of biological organization. This study examined the potential link between the liver microbiome profile and epigenetic factors.

METHODS

Liver microbial DNA composition was analysed using high throughput 16S rRNA gene sequencing in 116 individuals, with 55% being female, across the spectrum of liver disease severity. Total activity of histone deacetylases (HDACs) and acetyltransferases (HATs) was assayed in nuclear extracts from fresh liver samples. In addition, we measured the global 5-hydroxymethylcytosine (5-hmC) levels of liver DNA.

FINDINGS

Patients with MASLD showed a 2.07-fold increase (p = 0.013) in liver total HAT activity. Moreover, a correlation was observed between liver total HAT activity and the score for histological steatosis (Spearman's R = 0.60, p = 1.0E-3) and disease severity (R = 0.40, p = 2.0E-2). Liver HAT and HDAC activities also showed associations with the abundance of several liver bacterial DNAs. Additionally, liver global levels of 5-hmC showed negative correlation with the read number of Bacteroidetes (R = -0.62, p = 9.3E-4) and Gammaproteobacteria (R = -0.43, p = 3.2E-2), while it was positively correlated with the abundance of Acidobacteria (R = 0.42, p = 4.1E-2) and Actinobacteria (R = 0.47, p = 1.8E-2).

INTERPRETATION

The host liver epigenome, including the activity of enzymes involved in maintaining the balance between protein acetylation and deacetylation and the global DNA hydroxy-methylation status, may be the target of microbial signals.

FUNDING

Agencia Nacional de Promoción Científica y Tecnológica, FonCyT.

Machine-learning model comprising five clinical indices and liver stiffness measurement can accurately identify MASLD-related liver fibrosis

BACKGROUND & AIMS

aMAP score, as a hepatocellular carcinoma risk score, is proven to be associated with the degree of chronic hepatitis B-related liver fibrosis. We aimed to evaluate the ability of aMAP score for metabolic dysfunction-associated steatotic liver disease (MASLD; formerly NAFLD)-related fibrosis diagnosis and establish a machine-learning (ML) model to improve the diagnostic performance.

METHODS

A total of 946 biopsy-proved MASLD patients from China and the United States were included in the analysis. The aMAP score, demographic/clinical indices and liver stiffness measurement (LSM) were included in seven ML algorithms to build fibrosis diagnostic models in the training set (N = 703). The performance of ML models was evaluated in the external validation set (N = 125).

RESULTS

The AUROCs of aMAP versus fibrosis-4 index (FIB-4) and aspartate aminotransferase-platelet ratio (APRI) in cirrhosis and advanced fibrosis were (0.850 vs. 0.857 [P = 0.734], 0.735 [P = 0.001]) and (0.759 vs. 0.795 [P = 0.027], 0.709 [P = 0.049]). When using dual cut-off values, aMAP had a smaller uncertainty area and higher accuracy (26.9%, 86.6%) than FIB-4 (37.3%, 85.0%) and APRI (59.0%, 77.3%) in cirrhosis diagnosis. The seven ML models performed satisfactorily in most cases. In the validation set, the ML model comprising LSM and 5 indices (including age, sex, platelets, albumin and total bilirubin used in aMAP calculator), built by logistic regression algorithm (called LSM-plus model), exhibited excellent performance. In cirrhosis and advanced fibrosis detection, the LSM-plus model had higher accuracy (96.8%, 91.2%) than LSM alone (86.4%, 67.2%) and Agile score (76.0%, 83.2%), respectively. Additionally, the LSM-plus model also displayed high specificity (cirrhosis: 98.3%; advanced fibrosis: 92.6%) with satisfactory AUROC (0.932, 0.875, respectively) and sensitivity (88.9%, 82.4%, respectively).

CONCLUSIONS

The aMAP score is capable of diagnosing MASLD-related fibrosis. The LSM-plus model could accurately identify MASLD-related cirrhosis and advanced fibrosis.

Review and expert opinion on MAFLD, oxidative stress and multifunctional management

Metabolic-associated fatty-liver disease (MAFLD), previously known as non-alcoholic fatty liver disease, is the most widespread and emerging chronic liver disease worldwide, with increasing prevalence rates also in the Asia-Pacific region. The disease has a high socio-economic burden as it negatively impacts the finances and quality of life of individuals affected and has a major burden on healthcare systems. The most important pathological event in MAFLD aetiopathogenesis is oxidative stress, which leads to functional and structural abnormalities in the liver as well as being involved in the development of other concomitant cardiometabolic diseases. MAFLD is a rather complex multisystemic clinical condition involving liver damage and a wide spectrum of extrahepatic manifestations such as obesity, type 2 diabetes, metabolic syndrome and cardiovascular diseases. This complexity requires the cooperation of multiple experts to identify MAFLD at an early stage, treat associated comorbidities, and promptly refer the patient to the hepatologist when needed. This review summarizes the current knowledge about MAFLD and reports the opinion of a group of experts on the increasing prevalence and burden of the disease in the southeast Asia region, the current journey of patients with MAFLD in developing countries, the role of oxidative stress and antioxidant treatment, and the importance of a multidisciplinary approach for early diagnosis and disease management. This article is part of the Current clinical use of silymarin in the treatment of toxic liver diseases: a case series Special Issue: https://www.drugsincontext.com/special_issues/current-clinical-use-of-silymarin-in-the-treatment-of-toxic-liver-diseases-a-case-series.

The effects of time-restricted eating for patients with nonalcoholic fatty liver disease: a systematic review

Nonalcoholic fatty liver disease (NAFLD) represents a significant global health concern. Numerous investigations have explored the implications of time-restricted eating (TRE) in the management of NAFLD. Therefore, the objective of our study was to conduct a systematic review to summarize and analyze all randomized controlled trials (RCTs) of TRE for patients with NAFLD. A thorough literature search was executed across Embase, Cochrane Library, and PubMed databases, covering all records from their inception until 1 September 2023. All clinical studies of TRE for NAFLD were summarized and analyzed. Our systematic review included four RCTs, encompassing a total of 443 NAFLD patients. These studies varied in sample size from 32 to 271 participants. The TRE intervention was consistently applied in an 8-h window, over durations ranging from 4 weeks to 12 months. The findings suggest that TRE could offer several health benefits for NAFLD patients, such as improved liver health indicators like liver stiffness and intrahepatic triglyceride (IHTG) levels. Consequently, TRE appears to be a promising dietary intervention for NAFLD patients. However, it is premature to recommend TRE for patients with NAFLD. The existing body of research on the effects of TRE in NAFLD contexts is limited, underscoring the need for further high-quality studies to expand our understanding of TRE's benefits in treating NAFLD. Ongoing clinical trials may provide more insights into the effects of TRE in NAFLD.

Stemness markers in hepatocellular carcinoma of Eastern vs. Western population: Etiology matters?

Hepatocellular carcinoma (HCC) is one of the most common cancers with a high mortality rate. HCC development is associated with its underlying etiologies, mostly caused by infection of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV), alcohol, non-alcoholic fatty liver disease, and exposure to aflatoxins. These variables, together with human genetic susceptibility, contribute to HCC molecular heterogeneity, including at the cellular level. HCC initiation, tumor recurrence, and drug resistance rates have been attributed to the presence of liver cancer stem cells (CSC). This review summarizes available data regarding whether various HCC etiologies may be associated to the appearance of CSC biomarkers. It also described the genetic variations of tumoral tissues obtained from Western and Eastern populations, in particular to the oncogenic effect of HBV in the human genome.

Diagnostic and prognostic performance of the SAFE score in non-alcoholic fatty liver disease

BACKGROUND & AIMS

The steatosis-associated fibrosis estimator (SAFE) score was developed to detect clinically significant liver fibrosis in patients with NAFLD in the United States. We compare the performance of the SAFE score and other non-invasive tests to diagnose liver fibrosis and to correlate the scores with liver-related outcomes in patients with NAFLD in Hong Kong.

METHODS

This was a retrospective cohort study involving two data sets. The first cohort was a biopsy cohort of NAFLD patients (n = 279), and the second was a territory-wide cohort of NAFLD patients (n = 4603) retrieved from a territory-wide electronic healthcare database in Hong Kong.

RESULTS

In detecting significant fibrosis, liver stiffness measured by transient elastography had the highest area under the receiver operating characteristic curve (AUROC) (.844), followed by SAFE score (.773). SAFE score had the highest AUROC among blood-based algorithms (.773 vs. .746 for FIB-4, .697 for APRI). Based on cut-off values of SAFE score (0 and 100 points), 854 (18.6%), 1596 (34.6%) and 2153 (46.8%) were in the low-, intermediate- and high-risk groups, respectively, in the territory-wide cohort. Six (.7%), 15 (.9%) and 59 (2.7%) developed liver-related events in those three groups respectively. Among patients who had liver-related events at 5 years, using the high cut-off, SAFE score could predict 84.9% of patients accurately, compared to 40.9% for FIB-4 and 27.2% for APRI.

CONCLUSION

The SAFE score performed well and better than other blood-based markers in diagnosing significant fibrosis and predicting liver-related events in Asian patients with NAFLD.

Risk of alcohol-associated liver disease in the offspring of parents with alcohol-associated liver disease: A nationwide cohort study

BACKGROUND AND AIMS

Offspring of patients with alcohol-associated liver disease (ALD) may have a higher risk of ALD. We examined their risk of ALD and survival with ALD.

APPROACH AND RESULTS

We used Danish nationwide registries to identify the offspring of patients diagnosed with ALD in 1996-2018 and 20:1 matched comparators from the general population. They were followed for ALD diagnosis through 2018. We used landmark competing risk analysis to estimate the age-specific absolute and relative 10-year risks of ALD. ALD was diagnosed in 385 of 60,707 offspring and 2842 of 1,213,357 comparators during 0.7 and 14.0 million person-years of follow-up, respectively, yielding an incidence rate ratio of 2.73 (95% CI: 2.44-3.03). The risk of being diagnosed with ALD within the next 10 years peaked at age 55 years for offspring and age 57 years for comparators with 10-year risks of 1.66% (95% CI: 1.16-2.30) in offspring and 0.81% (95% CI: 0.68-0.97) in comparators at these ages. Offspring were younger at ALD diagnosis than comparators (median age of 47.4 vs. 48.9 years), yet slightly more of them had developed cirrhosis (60.3% vs. 58.7%). Survival after ALD diagnosis was similar in offspring and comparators, adjusted hazard ratio=1.03 (95% CI: 0.88-1.21), so on average offspring died younger due to their younger age at diagnosis.

CONCLUSIONS

Offspring of patients with ALD had a low but increased risk of ALD. Screening offspring for chronic liver disease may be unnecessary, but other interventions to mitigate alcohol-associated harm should be considered.

Familial coaggregation of MASLD with hepatocellular carcinoma and adverse liver outcomes: Nationwide multigenerational cohort study

BACKGROUND & AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly NAFLD) is the fastest growing cause of hepatocellular carcinoma (HCC) worldwide. However, whether family members of individuals with MASLD also share an increased risk of developing HCC is unknown.

METHODS

This nationwide multigenerational cohort study involved family members of all Swedish adults diagnosed with biopsy-proven MASLD (1969-2017), and matched general population comparators. Using the Swedish Multi-generation Register, we identified 38,018 first-degree relatives (FDRs: parents, siblings, offspring) and 9,381 spouses of patients with MASLD, as well as 197,303 comparator FDRs and 47,572 comparator spouses. We used Cox proportional hazards models to calculate adjusted hazard ratios (aHRs) for HCC, major adverse liver outcomes (cirrhosis, decompensated liver disease or liver transplantation), liver-related mortality, extrahepatic cancer, and non-liver-related mortality.

RESULTS

Over a median of 17.6 years, the rate of the primary outcome HCC was higher in MASLD FDRs vs. comparator FDRs (13 vs. 8/100,000 person-years [PY]; aHR 1.80, 95% CI 1.36-2.37). The HCC risk was further increased in FDRs of individuals with liver fibrosis/cirrhosis (aHR 2.14, 95% CI 1.07-4.27; PHeterogeneity = 0.03). MASLD FDRs also had higher rates of major adverse liver outcomes (73 vs. 51/100,000 PY; aHR 1.52, 95% CI 1.36-1.69) and liver-related mortality (20 vs. 11/100,000 PY; aHR 2.14, 95% CI 1.67-2.74). MASLD FDRs with any concomitant chronic liver condition experienced accelerated progression of liver disease (aHR 1.47, 95% CI 1.29-1.67). MASLD spouses were at higher risks of major adverse liver outcomes (86 vs. 74/100,000 PY; aHR 1.23, 95% CI 1.01-1.51) and liver-related mortality (25 vs. 19/100,000 PY; aHR 1.93, 95% CI 1.15-3.23), but not of HCC (aHR 1.43, 95% CI 0.87-2.35).

CONCLUSIONS

There is distinct familial clustering of adverse liver-related outcomes in families of individuals with biopsy-proven MASLD, with higher relative risks of HCC, progressive liver disease, and liver-related mortality, but absolute risks are low.

IMPACT AND IMPLICATIONS

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly termed NAFLD) clusters in families with high genetic susceptibility and shared environmental risk factors, but the risks of developing hepatocellular carcinoma and other major liver-related outcomes in family members of individuals with MASLD are largely unknown. This large nationwide multigenerational cohort study involving family members (first-degree relatives and spouses) of individuals with biopsy-proven MASLD and of matched general population comparators found slightly increased risks of hepatocellular carcinoma in first-degree relatives, and of developing cirrhosis and liver-related mortality in all family members of individuals with biopsy-proven MASLD. The findings of this study provide large-scale evidence to inform clinical practice guidelines for recommendations on the early identification of individuals at higher risk of liver-related morbidity and mortality.

Mixture of Peanut Skin Extract, Geniposide, and Isoquercitrin Improves the Hepatic Lipid Accumulation of Mice via Modification of Gut Microbiota Homeostasis and the TLR4 and AMPK Signaling Pathways

Metabolic-dysfunction-associated steatotic liver disease (MASLD, formerly known as NAFLD) is a global chronic liver disease, and no licensed drugs are currently available for its treatment. The incidence of MASLD is increasing, which could lead to a huge clinical and economic burden. As a multifactorial disease, MASLD involves a complex set of metabolic changes, and many monotherapies for it are not clinically effective. Therefore, combination therapies using multiple drugs are emerging, with the advantages of improving drug efficacy and reducing side effects. Peanut skin extract (PSE), geniposide (GEN), and isoquercitrin (IQ) are three natural antiaging components or compounds. In this study, the preventive effects of individual PSE, GEN, and IQ in comparison with the effects of their mixture (MPGI) were examined in a mouse model of high-fat-feed-induced MASLD. The results showed that MPGI could significantly reduce the body and liver weights of mice and improve hepatic steatosis and liver function indicators. Further mechanistic studies showed that PSE, GEN, and IQ worked together by reducing inflammation, modulating the intestinal flora, and regulating the TLR4/NF-κB, AMPK/ACC/CPT1, and AMPK/UKL1/LC3B signaling pathways. It is a promising therapeutic method for preventing MASLD.

Prediction of clinical events by liver stiffness and chronic kidney disease by NAFLD in patients with type-2 diabetes

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with poorer glycemic control and a higher risk of type-2 diabetes (T2D) complications, extrahepatic and cardiovascular disease (CVD). Our study aim was to evaluate the association between NAFLD, T2D complications, and the development of overall clinical events (OCE) (CV, liver-related, and mortality) in patients with T2D.

METHODS

Prospective single-center study comprising T2D subjects with no history of CVD and non-T2D matched controls. Patients were selected from the Outpatient Diabetes Clinic of Vall d'Hebron Hospital and related primary care centers.

RESULTS

186 diabetics and 57 controls were included. Amongst T2D, 124/186 subjects had NAFLD (66.6%). T2D-NAFLD subjects showed a heavier metabolic burden and higher median liver stiffness (5.6kPa [4.5-7.3] vs 4.8 [4.2-5.8]; p=0.004) compared to non-NAFLD diabetics. During a median follow-up of 5.6 years, 33 (17.7%) T2D patients developed OCE vs 4 (7.0%) controls (p=0.049). No differences were found for OCE between NAFLD and non-NAFLD diabetics (16.9% vs 19.4%; p=0.68). CV was the most reported outcome and only one liver event occurred. NAFLD diabetics showed more often chronic kidney disease (CKD), whereas T2D complications and subclinical CVD rates were similar. A higher liver stiffness, older age, and male gender were independently associated with OCE amongst the entire T2D population and NAFLD diabetics.

CONCLUSIONS

NAFLD and liver stiffness were associated with CKD and clinical outcomes in diabetics, respectively. A hepatic evaluation is recommended to identify high-risk T2D patients that would benefit from early referral to specialized care.

Towards precision medicine in non-alcoholic fatty liver disease

Non-Alcoholic Fatty Liver Disease (NAFLD) refers to the accumulation of lipid laden vacuoles in hepatocytes, occurring in the context of visceral adiposity, insulin resistance and other features of the metabolic syndrome. Its more severe form (NASH, Non-Alcoholic Steatohepatitis) is becoming the leading aetiology of end-stage liver disease and hepatocellular carcinoma, and also contributes to cardiovascular disease, diabetes and extrahepatic malignancy. Management is currently limited to lifestyle modification and optimisation of the metabolic co-morbidities, with some of the drugs used for the latter also having shown some benefit for the liver. Licensed treatment modalities are currently lacking. A particular difficulty is the notorious heterogeneity of the patient population, which is poorly understood. A spectrum of disease severity associates in a non-linear way with a spectrum of severity of underlying metabolic factors. Heterogeneity of the liver in terms of mechanisms to cope with the metabolic and inflammatory stress and in terms of repair mechanisms, and a lack of knowledge hereof, further complicate the understanding of inter-individual variability. Genetic factors act as disease modifiers and potentially allow for some risk stratification, but also only explain a minor fraction of disease heterogeneity. Response to treatment shows a large variation in treatment response, again with little understanding of what is driving the absence of response in individual patients. Management can be tailored to patient's preferences in terms of diet modification, but tailoring treatment to knowledge on disease driving mechanisms in an individual patient is still in its infancy. Recent progress in analysing liver tissue as well as non-invasive tests hold, however, promise to rapidly improve our understanding of disease heterogeneity in NAFLD and provide individualised management.

Changing epidemiology, global trends and implications for outcomes of NAFLD

Non-alcoholic fatty liver disease (NAFLD) has rapidly become the most common liver disease globally and is currently estimated to affect 38% of the global population. Only a minority of patients with NAFLD will progress to cirrhosis or hepatocellular carcinoma, but from this vast population the total number of patients who are at risk of such severe outcomes is increasing. Worryingly, individuals are increasingly being affected by NAFLD at an earlier age, meaning there is more time for them to develop severe complications. With considerable changes in dietary composition and urbanisation, alongside the growth in obesity and type 2 diabetes in the global population, in particular in developing countries, the global proportion of persons affected by NAFLD is projected to increase further. Yet, there are large geographical discrepancies in the prevalence rates of NAFLD and its inflammatory component non-alcoholic steatohepatitis (NASH). Such differences are partly related to differing socio-economic milieus, but also to genetic predisposition. In this narrative review, we discuss recent changes in the epidemiology of NAFLD and NASH from regional and global perspectives, as well as in special populations. We also discuss the potential consequences of these changes on hepatic and extrahepatic events.

Timing of energy intake and the therapeutic potential of intermittent fasting and time-restricted eating in NAFLD

Non-alcoholic fatty liver disease (NAFLD) represents a major public health concern and is associated with a substantial global burden of liver-related and cardiovascular-related morbidity and mortality. High total energy intake coupled with unhealthy consumption of ultra-processed foods and saturated fats have long been regarded as major dietary drivers of NAFLD. However, there is an accumulating body of evidence demonstrating that the timing of energy intake across a the day is also an important determinant of individual risk for NAFLD and associated metabolic conditions. This review summarises the available observational and epidemiological data describing associations between eating patterns and metabolic disease, including the negative effects of irregular meal patterns, skipping breakfast and night-time eating on liver health. We suggest that that these harmful behaviours deserve greater consideration in the risk stratification and management of patients with NAFLD particularly in a 24-hour society with continuous availability of food and with up to 20% of the population now engaged in shiftwork with mistimed eating patterns. We also draw on studies reporting the liver-specific impact of Ramadan, which represents a unique real-world opportunity to explore the physiological impact of fasting. By highlighting data from preclinical and pilot human studies, we present a further biological rationale for manipulating timing of energy intake to improve metabolic health and discuss how this may be mediated through restoration of natural circadian rhythms. Lastly, we comprehensively review the landscape of human trials of intermittent fasting and time-restricted eating in metabolic disease and offer a look to the future about how these dietary strategies may benefit patients with NAFLD and non-alcoholic steatohepatitis.

Noninvasive Assessment of Liver Fibrosis in NAFLD

Nonalcoholic fatty liver disease (NAFLD) has emerged as a leading cause of liver-related morbidity and mortality worldwide, afflicting approximately a billion individuals. NAFLD is a slowly progressive disease that may evolve in a subset of patients toward cirrhosis, hepatocellular carcinoma, and end-stage liver disease. Liver fibrosis severity is the strongest predictor of clinical outcomes. The emergence of effective therapeutics on the horizon highlights the need to identify among patients with NAFLD, those with severe fibrosis or cirrhosis, who are the most at risk of developing complications and target them for therapy. Liver biopsy has been the reference standard for this purpose. However, it is not suitable for large-scale population evaluation, given its well-known limitations (invasiveness, rare but severe complications, and sampling variability). Thus, there have been major efforts to develop simple noninvasive tools that can be used in routine clinical settings and in drug development. Noninvasive approaches are based on the quantification of biomarkers in serum samples or on the measurement of liver stiffness, using either ultrasound- or magnetic resonance-based elastography techniques. This review provides a roadmap for future development and integration of noninvasive tools in clinical practice and in drug development in NAFLD. We discuss herein the principles for their development and validation, their use in clinical practice, including for diagnosis of NAFLD, risk stratification in primary care and hepatology settings, prediction of long-term liver-related and non-liver-related outcomes, monitoring of fibrosis progression and regression, and response to future treatment.

Precision Medicine in Fatty Liver Disease/Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, and is related to fatal and non-fatal liver, metabolic, and cardiovascular complications. Its non-invasive diagnosis and effective treatment remain an unmet clinical need. NAFLD is a heterogeneous disease that is most commonly present in the context of metabolic syndrome and obesity, but not uncommonly, may also be present without metabolic abnormalities and in subjects with normal body mass index. Therefore, a more specific pathophysiology-based subcategorization of fatty liver disease (FLD) is needed to better understand, diagnose, and treat patients with FLD. A precision medicine approach for FLD is expected to improve patient care, decrease long-term disease outcomes, and develop better-targeted, more effective treatments. We present herein a precision medicine approach for FLD based on our recently proposed subcategorization, which includes the metabolic-associated FLD (MAFLD) (i.e., obesity-associated FLD (OAFLD), sarcopenia-associated FLD (SAFLD, and lipodystrophy-associated FLD (LAFLD)), genetics-associated FLD (GAFLD), FLD of multiple/unknown causes (XAFLD), and combined causes of FLD (CAFLD) as well as advanced stage fibrotic FLD (FAFLD) and end-stage FLD (ESFLD) subcategories. These and other related advances, as a whole, are expected to enable not only improved patient care, quality of life, and long-term disease outcomes, but also a considerable reduction in healthcare system costs associated with FLD, along with more options for better-targeted, more effective treatments in the near future.

Advances in our understanding of the molecular heterogeneity of fatty liver disease: toward informed treatment decision making

INTRODUCTION

nonalcoholic fatty liver disease (NAFLD) is a complex disorder resulting from intricate relationships with diverse cardiometabolic risk factors and environmental factors. NAFLD may result in severe chronic liver damage and potentially declining liver function.

AREAS COVERED

Accumulated knowledge over the last decade indicates that the disease trajectory presents substantial heterogeneity. In addition, overlapping features with the diseases of the metabolic syndrome, combined with heterogeneity in disease mechanisms, further complicates NAFLD diagnosis and prognosis, and hampers progress in biomarker and pharmacological discoveries. Here, we explore solving the heterogeneous clinical landscape of NAFLD by cluster analysis of molecular signatures that serve as a proxy for disease stratification into molecular sub-types. First, we collected information on NAFLD and metabolic syndrome-associated protein-coding genes by data mining the literature. Next, we performed pathways enrichment and cluster analyses to decipher and dissect the different patterns of phenotypic heterogeneity. Our approach showed unique biological pathways for every clinical subtype/group, namely NAFLD + obesity, NAFLD + arterial hypertension, NAFLD + dyslipidemia, and NAFLD + type 2 diabetes.

EXPERT OPINION

Patients with NAFLD may be benefited by a better understanding of the disease biology, which involves 'dissection' of the molecular sub-phenotypes that drive the disease progression.

Fibroblast Growth Factors for Nonalcoholic Fatty Liver Disease: Opportunities and Challenges

Nonalcoholic fatty liver disease (NAFLD), a chronic condition associated with metabolic dysfunction and obesity, has reached epidemic proportions worldwide. Although early NAFLD can be treated with lifestyle changes, the treatment of advanced liver pathology, such as nonalcoholic steatohepatitis (NASH), remains a challenge. There are currently no FDA-approved drugs for NAFLD. Fibroblast growth factors (FGFs) play essential roles in lipid and carbohydrate metabolism and have recently emerged as promising therapeutic agents for metabolic diseases. Among them, endocrine members (FGF19 and FGF21) and classical members (FGF1 and FGF4) are key regulators of energy metabolism. FGF-based therapies have shown therapeutic benefits in patients with NAFLD, and substantial progress has recently been made in clinical trials. These FGF analogs are effective in alleviating steatosis, liver inflammation, and fibrosis. In this review, we describe the biology of four metabolism-related FGFs (FGF19, FGF21, FGF1, and FGF4) and their basic action mechanisms, and then summarize recent advances in the biopharmaceutical development of FGF-based therapies for patients with NAFLD.

Non-invasive biomarkers for liver inflammation in non-alcoholic fatty liver disease: present and future

Inflammation is the key driver of liver fibrosis progression in non-alcoholic fatty liver disease (NAFLD). Unfortunately, it is often challenging to assess inflammation in NAFLD due to its dynamic nature and poor correlation with liver biochemical markers. Liver histology keeps its role as the standard tool, yet it is well-known for substantial sampling, intraobserver, and interobserver variability. Serum proinflammatory cytokines and apoptotic markers, namely cytokeratin-18, are well-studied with reasonable accuracy, whereas serum metabolomics and lipidomics have been adopted in some commercially available diagnostic models. Ultrasound and computed tomography imaging techniques are attractive due to their wide availability; yet their accuracies may not be comparable with magnetic resonance imaging-based tools. Machine learning and deep learning models, be they supervised or unsupervised learning, are promising tools to identify various subtypes of NAFLD, including those with dominating liver inflammation, contributing to sustainable care pathways for NAFLD.

Genetics in non-alcoholic fatty liver disease: The role of risk alleles through the lens of immune response

The knowledge on the genetic component of non-alcoholic fatty liver disease (NAFLD) has grown exponentially over the last 10 to 15 years. This review summarizes the current evidence and the latest developments in the genetics of NAFLD and non-alcoholic steatohepatitis (NASH) from the immune system's perspective. Activation of innate and or adaptive immune response is an essential driver of NAFLD disease severity and progression. Lipid and immune pathways are crucial in the pathophysiology of NAFLD and NASH. Here, we highlight novel applications of genomic techniques, including single-cell sequencing and the genetics of gene expression, to elucidate the potential involvement of NAFLD/NASH-risk alleles in modulating immune system cells. Together, our focus is to provide an overview of the potential involvement of the NAFLD/NASH-related risk variants in mediating the immune-driven liver disease severity and diverse systemic pleiotropic effects.

Clinical features and metabolic complications for non-alcoholic fatty liver disease (NAFLD) in youth with obesity

Pediatric obesity has become in the last forty years the most common metabolic disease in children and adolescents affecting about 25% of the pediatric population in the western world. As obesity worsens, a whole-body insulin resistance (IR) occurs. This phenomenon is more pronounced during adolescence, when youth experience a high degree of insulin resistance due the production of growth hormone. As IR progresses, the blunted control of insulin on adipose tissue lipolysis causes an increased flux of fatty acids with FFA deposition in ectopic tissues and organs such as the liver, leading to the development of NAFLD. In this brief review, we will discuss the clinical implications of IR and NAFLD in the context of pediatric obesity. We will review the pathogenesis and the link between these two entities, the major pathophysiologic underpinnings, including the role of genetics and metagenomics, how these two entities lead to the development of type 2 diabetes, and which are the therapeutic options for NAFLD in youth.

Genetic Polymorphisms and Diversity in Nonalcoholic Fatty Liver Disease (NAFLD): A Mini Review

Nonalcoholic fatty liver disease (NAFLD) is a common liver disease with a wide spectrum of liver conditions ranging from hepatic steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. The prevalence of NAFLD varies across populations, and different ethnicities have specific risks for the disease. NAFLD is a multi-factorial disease where the genetics, metabolic, and environmental factors interplay and modulate the disease's development and progression. Several genetic polymorphisms have been identified and are associated with the disease risk. This mini-review discussed the NAFLD's genetic polymorphisms and focusing on the differences in the findings between the populations (diversity), including of those reports that did not show any significant association. The challenges of genetic diversity are also summarized. Understanding the genetic contribution of NAFLD will allow for better diagnosis and management explicitly tailored for the various populations.

Pemafibrate improves liver dysfunction and non-invasive surrogates for liver fibrosis in patients with non-alcoholic fatty liver disease with hypertriglyceridemia: a multicenter study

BACKGROUND

This retrospective, multicenter study evaluated the effect of pemafibrate treatment on liver function and fibrosis by liver function tests (LFTs) and various fibrotic biomarkers including FibroScan in non-alcoholic fatty liver disease (NAFLD) with hypertriglyceridemia.

METHODS

A total of 138 NAFLD patients treated with pemafibrate at three hospitals between September 2018 and April 2021 were included. To evaluate the effect of pemafibrate treatment, FibroScan-aspartate aminotransferase (FAST) score, a novel index of steatohepatitis that can be calculated based on the aspartate aminotransferase (AST) value, controlled attenuation parameter (CAP), and liver stiffness measurement (LSM) was used.

RESULTS

Serum TG levels were significantly decreased 4 weeks after pemafibrate treatment (p = 0.003). The levels of AST (p = 0.038), alanine aminotransferase (ALT) (p = 0.003), and gamma-glutamyl transferase (GGT) (p = 0.047) also significantly diminished 12 weeks after pemafibrate administration compared to before administration (p < 0.05). However, serum HDL-cholesterol (p = 0.193), LDL-cholesterol (p = 0.967), and eGFR (p = 0.909) levels were not significantly altered 12 weeks after pemafibrate administration. In addition, the fibrosis biomarkers' Type IV collagen (p = 0.753) and FIB-4 index (p = 0.333) did not significantly differ, while Autotaxin (p = 0.006) and the AST-to-platelet ratio index (APRI) (p = 0.003) significantly decreased 48 weeks after pemafibrate administration. No significant reductions in LSM (p = 0.959) and CAP (p = 0.266) were detected using FibroScan 48 weeks after pemafibrate administration. FAST score was significantly improved (p = 0.0475).

CONCLUSION

Pemafibrate improved LFTs, including fibrotic biomarkers and FAST score, due to the hepatic anti-inflammatory effect, suggesting that pemafibrate may prevent disease progression in NAFLD patients with hypertriglyceridemia.

TSH-SPP1/TRβ-TSH positive feedback loop mediates fat deposition of hepatocyte: Crosstalk between thyroid and liver

Aims

We conducted this study with two aims: (1) whether TRβ could be damaged by NAFLD, thereby represent thyroid hormone resistance-like manifestation and (2) to analyze the potential role of SPP1 in TH signaling pathway on the process of NAFLD. This study is expected to provide a new perspective on the therapeutic mechanism in the pathological course of NAFLD.

Methods

A total of 166 patients diagnosed with type 2 diabetes mellitus (T2DM) were enrolled in this study. All patients had a BMI above 24 kg/m2 and were stratified into two groups: NAFLD and Non-NAFLD groups. Ages, gender, BMI, duration of diabetes and biochemical markers were obtained from participants' records. We downloaded the dataset GSE48452 from GEO. The Pathview library was used to make the thyroid hormone signaling pathway visualization. The CIBERSORT algorithm was applied to calculate the infiltrated immune cells in obese NAFLD patients. C57BL/6 mice were randomly selected to constitute the normal control (NC) group and were fed a normal chow diet; the rest of the mice were fed a high-fat diet (HFD). After 12 weeks HFD feeding, the mice were sacrificed by cervical dislocation, and blood samples were collected. Mouse livers were also collected; one part of each liver was fixed in 10% formalin for histological analysis, and the other part was snap-frozen for subsequent molecular analyses. To explore the relationship between SPP1, TRβ and lipid deposition in hepatocytes, HepG2 cells were treated with 50 μ M concentration of PA and/or 20 ng/ml concentration of rh-SPP1 for 48h. In addition, the PC3.1-TRβ plasmid was constructed for further validation in HepG2 cells. We used THP-1 cells to construct an M1 macrophage model in vitro. We then analyzed THP-1 cells treated with various concentrations of PA or TSH.

Results

(1) After adjusting for all factors that appeared P value less than 0.1 in the univariate analysis, BMI, TSH, and FT3 were significant independent risk factors of NAFLD (ORs were 1.218, 1.694, and 2.259, respectively); (2) A further analysis with BMI stratification indiacted that both FT3 and TSH had a significant change between individuals with NAFLD and Non-NAFLD in obesity subgroup; however, there was no statistic difference in over-weight group; (3) Bioinformatics analysis of GSE48452 had shown that several key molecular (including TRβ) of thyroid hormone pathway affected by NAFLD induced transcriptomic changes and the expression levels of SPP1, FABP4 and RPS4Y1 were significantly higher, while the expression levels of PZP and VIL1 were significantly decreased in NAFLD patients(adjusted p < 0.05, |logFC| > 1.0). The CIBERSORT algorithm showed increased M0 and M1, decreased M2 macrophage infiltration in NAFLD with comparison to healthy obese group; (4) After 12 weeks of HFD-feeding, the obesity mice had significantly higher serum TSH and In IHC-stained liver sections of obesity group, the intensity of SPP1 had a significantly increased, while TRβ reduced; (5) In vitro studies have shown SPP1 aggravated lipid deposition in hepatic cells dependent on down-regulating the expression of TRβ and TSH acts to promote secretion of SPP1 in M1 macrophage cells.

Conclusions

SPP1 secretion induced by M1 macrophage polarization, which may down-regulates TRβ in hepatocytes via paracrine manner, on the one hand, the lipid deposition aggravating in liver, on the other hand, a compensatory increase of TSH in serum. The increased TSH can further lead to the following SPP1 secretion of M1 macrophage. The positive feedback crosstalk between thyroid and liver, may be plays an important role in maintaining and amplifying pathological process of NAFLD.