MAFLD vs NAFLD: Where are we?

Management of Metabolic-Associated Fatty Liver Disease/Metabolic Dysfunction-Associated Steatotic Liver Disease: From Medication Therapy to Nutritional Interventions

Non-alcoholic fatty liver disease (NAFLD) is a common long-lasting liver disease that affects millions of people around the world. It is best identified with a hepatic fat build-up that ultimately leads to inflammation and damage. The classification and nomenclature of NAFLD have long been a controversial topic, until 2020 when a group of international experts recommended substituting NAFLD with MAFLD (metabolic dysfunction-associated FLD). MAFLD was then terminologically complemented in 2023 by altering it to MASLD, i.e., metabolic dysfunction-associated steatotic liver disease (MASLD). Both the MAFLD and the MASLD terminologies comprise the metabolic element of the disorder, as they offer diagnostic benchmarks that are embedded in the metabolic risk factors that underlie the disease. MASLD (as a multisystemic disease) provides a comprehensive definition that includes a larger population of patients who are at risk of liver morbidity and mortality, as well as adverse cardiovascular and diabetes outcomes. MASLD highlights metabolic risks in lean or normal weight individuals, a factor that has not been accentuated or discussed in previous guidelines. Novel antihyperglycemic agents, anti-hyperlipidemic drugs, lifestyle modifications, nutritional interventions, and exercise therapies have not been extensively studied in MAFLD and MASLD. Nutrition plays a vital role in managing both conditions, where centralizing on a diet rich in whole vegetables, fruits, foods, healthy fats, lean proteins, and specific nutrients (e.g., omega-3 fatty acids and fibers) can improve insulin resistance and reduce inflammation. Thus, it is essential to understand the role of nutrition in managing these conditions and to work with patients to develop an individualized plan for optimal health. This review discusses prevention strategies for NAFLD/MAFLD/MASLD management, with particular attention to nutrition and lifestyle correction.

Time course of western diet (WD) induced nonalcoholic steatohepatitis (NASH) in female and male Ldlr-/- mice

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a global health problem. Identification of factors contributing to the onset and progression of NAFLD have the potential to direct novel strategies to combat NAFLD.

METHODS

We examined the time course of western diet (WD)-induced NAFLD and its progression to nonalcoholic steatohepatitis (NASH) in age-matched female and male Ldlr-/- mice, with time-points at 1, 4, 8, 20 and 40 weeks on the WD. Controls included Ldlr-/- mice maintained on a purified low-fat diet (LFD) for 1 and 40 weeks. The approach included quantitation of anthropometric, plasma and liver markers of disease, plus hepatic histology, lipids, oxylipins, gene expression and selected metabolites.

RESULTS

One week of feeding the WD caused a significant reduction in hepatic essential fatty acids (EFAs: 18:2, ω6, 18:3, ω3) which preceded the decline in many C20-22 ω3 and ω6 polyunsaturated fatty acids (PUFA) and PUFA-derived oxylipins after 4 weeks on the WD. In addition, expression of hepatic inflammation markers (CD40, CD44, Mcp1, Nlrp3, TLR2, TLR4, Trem2) increased significantly in both female & male mice after one week on the WD. These markers continued to increase over the 40-week WD feeding study. WD effects on hepatic EFA and inflammation preceded all significant WD-induced changes in body weight, insulin resistance (HOMA-IR), oxidative stress status (GSH/GSSG ratio) and histological and gene expression markers of macrosteatosis, extracellular matrix remodeling and fibrosis.

CONCLUSIONS

Our findings establish that feeding Ldlr-/- mice the WD rapidly lowered hepatic EFAs and induced key inflammatory markers linked to NASH. Since EFAs have an established role in inflammation and hepatic inflammation plays a major role in NASH, we suggest that early clinical assessment of EFA status and correcting EFA deficiencies may be useful in reducing NASH severity.

Adherence to healthy lifestyle was associated with an attenuation of the risk of chronic kidney disease from metabolic dysfunction-associated fatty liver disease: Results from two prospective cohorts

AIMS

Non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD) are important risk factors of chronic kidney disease (CKD). Whether adherence to a healthy lifestyle can modify these effects remain unknown. This study aimed to evaluate the modification effects of healthy lifestyle on the associations among NAFLD, MAFLD, and the risk of CKD, with taking into the effect of genetic risk.

METHODS

The Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study (TCLSIH), the UK Biobank Study (UKB). The outcome was incident CKD. The exposures including NAFLD, MAFLD, healthy lifestyle, and a genetic risk score (GRS) for CKD.

RESULTS

After 1,135,334 person-year follow-up, we documented 2975 incident CKD cases in the two cohorts. MAFLD and NAFLD were associated with a higher risk of CKD, particularly in patients with MAFLD. In the TCLSIH and UKB, the hazard ratios (95% confidence intervals) of incident CKD for MAFLD were 1.47 (1.30, 1.66) and 1.73 (1.57, 1.91), respectively. Adherence to a healthier lifestyle decreased the risk of CKD from MAFLD with significant interaction effects (TCLSIH: Pinteraction = 0.02; UKB: Pinteraction = 0.04). Participants with a lower CKD-GRS experienced a higher risk of CKD from MAFLD, but achieved two healthy lifestyles can significantly decreased the risk of CKD in patients with MAFLD.

CONCLUSIONS

MAFLD and NAFLD are associated with a higher CKD risk, particularly MAFLD. Adherence to a healthier lifestyle was associated with a lower risk of CKD from MAFLD. These results highlight the important role of following a healthy lifestyle to prevent CKD.

Coincidental items in the definition of metabolic dysfunction-associated fatty liver are useful in identifying patients having significant fibrosis with fatty liver

AIM

We aimed to establish a method that will identify patients at a high risk for progressive phenotype of fatty liver.

METHODS

Patients with fatty liver who underwent liver biopsy between July 2008 and November 2019 were included as cohort 1, and those who underwent abdominal ultrasound screening examination by general physicians between August 2020 and May 2022 served as cohort 2. According to the definition of metabolic dysfunction-associated fatty liver (MAFLD), the subjects were classified by body mass index of ≥23, diabetes mellitus, and coexistence of two or more metabolic risk items. The progressive phenotype of MAFLD is defined by significant fibrosis complicated with either nonalcoholic fatty liver disease activity score ≥4 (BpMAFLD) or steatosis grade ≥2 by ultrasound examination (UpMAFLD).

RESULTS

One hundred sixty-eight patients and 233 patients were enrolled in cohorts 1 and 2, respectively. In cohort 1, the prevalence of BpMAFLD was 0% in patients without a complicating factor (n = 10), 13% in those with one complicating factor (n = 67), 32% in those with two (n = 73), and 44% in those with all three complicating factors (n = 36). A logistic regression analysis revealed that factors in the MAFLD definition were significantly associated with BpMAFLD. In cohort 2, a criterion of two or more positive MAFLD definitions was found to have a 97.4% negative predictive value for the diagnosis of UpMAFLD.

CONCLUSION

Patients with two or more complicating factors in the MAFLD definition should have further evaluation for liver fibrosis.

Nonalcoholic Fatty Liver Disease and Omega-3 Fatty Acids: Mechanisms and Clinical Use

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic fatty liver disease worldwide, particularly in obese and type 2 diabetic individuals. Currently, there are no therapies for NAFLD that have been approved by the US Food and Drug Administration. Herein, we examine the rationale for using ω3 polyunsaturated fatty acids (PUFAs) in NAFLD therapy. This focus is based on the finding that NAFLD severity is associated with a reduction of hepatic C20-22 ω3 PUFAs. Because C20-22 ω3 PUFAs are pleiotropic regulators of cell function, loss of C20-22 ω3 PUFAs has the potential to significantly impact hepatic function. We describe NAFLD prevalence and pathophysiology as well as current NAFLD therapies. We also present evidence from clinical and preclinical studies that evaluated the capacity of C20-22 ω3 PUFAs to treat NAFLD. Given the clinical and preclinical evidence, dietary C20-22 ω3 PUFA supplementation has the potential to decrease human NAFLD severity by reducing hepatosteatosis and liver injury.

The independent and combined effects of dietary and sleep patterns on the risk of metabolic dysfunction-associated fatty liver disease: a population-based cohort study

Background & aims: accumulating evidence shows that various sleep behaviors are related to metabolic dysfunction-associated fatty liver disease (MAFLD), and that diet plays an important role in both preventing and treating this condition. However, the overall effect of a healthy sleep pattern and its joint effect with diet on the risk of MAFLD remain unclear. The aim of this study is to explore the independent and combined effects of dietary and sleep patterns on the MAFLD risk. Methods: this population-based prospective cohort study was conducted in China with a sample size of 13 687 participants. MAFLD was diagnosed through abdominal ultrasound and international expert consensus. Five healthy sleep behaviors were identified to create a healthy sleep pattern, while factor analysis was used to determine dietary patterns. Cox proportional hazards regression was utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: during a total of 49 912 person-years of follow-up, 2977 new cases of MAFLD were identified. The adjusted HRs (95% CIs) of MAFLD in relation to the healthy sleep pattern score were 0.87 (0.78-0.97), 0.83 (0.75-0.92), and 0.77 (0.68-0.87) for scores of 3, 4, and 5, respectively, compared to participants with the lowest score (0-2). A higher intake of animal food (adjusted HR_{4th quartile vs. 1st quartile}, 1.15, 95% CI, 1.03-1.27) and a lower intake of vegetables (adjusted HR_{4th quartile vs. 1st quartile}, 0.88, 95% CI, 0.78-0.99) were associated with a higher risk of MAFLD. Participants who adhered to both healthy dietary and sleep patterns had the lowest MAFLD risk compared to those who followed only one or neither of them. Conclusions: a healthy sleep pattern, especially in combination with a healthy diet, was associated with a lower risk of MAFLD. Future prevention strategies for MAFLD should include consideration of sleep behaviors, in addition to the current recommendations.

NAFLD, MAFLD, and beyond: one or several acronyms for better comprehension and patient care

The term non-alcoholic fatty liver disease (NAFLD) has rapidly become the most common type of chronic liver disease. NAFLD points to excessive hepatic fat storage and no evidence of secondary hepatic fat accumulation in patients with "no or little alcohol consumption". Both the etiology and pathogenesis of NAFLD are largely unknown, and a definitive therapy is lacking. Since NAFLD is very often and closely associated with metabolic dysfunctions, a consensus process is ongoing to shift the acronym NAFLD to MAFLD, i.e., metabolic-associated fatty liver disease. The change in terminology is likely to improve the classification of affected individuals, the disease awareness, the comprehension of the terminology and pathophysiological aspects involved, and the choice of more personalized therapeutic approaches while avoiding the intrinsic stigmatization due to the term "non-alcoholic". Even more recently, other sub-classifications have been proposed to concentrate the heterogeneous causes of fatty liver disease under one umbrella. While awaiting additional validation studies in this field, we discuss the main reasons underlying this important shift of paradigm.

Therapeutic Effects of microRNAs on Nonalcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH): A Systematic Review and Meta-Analysis

Nonalcoholic fatty liver disease (NAFLD) has emerged as a global health problem that affects people even at young ages due to unhealthy lifestyles. Without intervention, NAFLD will develop into nonalcoholic steatohepatitis (NASH) and eventually liver cirrhosis and hepatocellular carcinoma. Although lifestyle interventions are therapeutic, effective implementation remains challenging. In the efforts to establish effective treatment for NAFLD/NASH, microRNA (miRNA)-based therapies began to evolve in the last decade. Therefore, this systematic review aims to summarize current knowledge on the promising miRNA-based approaches in NAFLD/NASH therapies. A current systematic evaluation and a meta-analysis were conducted according to the PRISMA statement. In addition, a comprehensive exploration of PubMed, Cochrane, and Scopus databases was conducted to perform article searches. A total of 56 different miRNAs were reported as potential therapeutic agents in these studies. miRNA-34a antagonist/inhibitor was found to be the most studied variant (n = 7), and it significantly improved the hepatic total cholesterol, total triglyceride, Aspartate Aminotransferase (AST), and Alanine Transaminase (ALT) levels based on a meta-analysis. The biological processes mediated by these miRNAs involved hepatic fat accumulation, inflammation, and fibrosis. miRNAs have shown enormous therapeutic potential in the management of NAFLD/NASH, wherein miRNA-34a antagonist has been found to be an exceptional potential agent for the treatment of NAFLD/NASH.

Comparison between metabolic-associated fatty liver disease and nonalcoholic fatty liver disease: From nomenclature to clinical outcomes

As a result of the obesity epidemic, Nonalcoholic fatty liver disease (NAFLD) and its complications have increased among millions of people. Consequently, a group of experts recommended changing the term NAFLD to an inclusive terminology more reflective of the underlying pathogenesis; metabolic-associated fatty liver disease (MAFLD). This new term of MAFLD has its own disease epidemiology and clinical outcomes prompting efforts in studying its differences from NAFLD. This article discusses the rationale behind the nomenclature change, the main differences, and its clinical implications.

A Review of the Effects of Fucoxanthin on NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease. Fucoxanthin, a red-orange marine carotenoid, is found in natural marine seaweeds with high antioxidant activity and several other remarkable biological features. The aim of this review is to gather evidence of the positive benefits of fucoxanthin on NAFLD. Fucoxanthin provides an extensive list of physiological and biological properties, such as hepatoprotective, anti-obesity, anti-tumor, and anti-diabetes properties, in addition to antioxidant and anti-inflammatory properties. This review focuses on published research on the preventative effects of fucoxanthin on NAFLD from the perspective of human clinical trials, animal experiments in vivo, and in vitro cell investigations. Using a variety of experimental designs, including treatment dosage, experiment model, and experimental periods, the positive effects of fucoxanthin were demonstrated. Fucoxanthin's biological activities were outlined, with an emphasis on its therapeutic efficacy in NAFLD. Fucoxanthin showed beneficial effects in modulating lipid metabolism, lipogenesis, fatty acid oxidation, adipogenesis, and oxidative stress on NAFLD. A deeper comprehension of NAFLD pathogenesis is essential for the development of novel and effective therapeutic strategies.

An Observational Data Meta-analysis on the Differences in Prevalence and Risk Factors Between MAFLD vs NAFLD

BACKGROUND & AIMS

The shift to redefine nonalcoholic fatty liver disease (NAFLD) as metabolic associated fatty liver disease (MAFLD) can profoundly affect patient care, health care professionals, and progress within the field. To date, there remains no consensus on the characterization of NAFLD vs MAFLD. Thus, this study sought to compare the differences between the natural history of NAFLD and MAFLD.

METHODS

Medline and Embase databases were searched to include articles on prevalence, risk factors, or outcomes of patients with MAFLD or NAFLD. Meta-analysis of proportions was conducted using the generalized linear mix model. Risk factors and outcomes were evaluated in conventional pairwise meta-analysis.

RESULTS

Twenty-two articles involving 379,801 patients were included. Pooled prevalence of MAFLD was 39.22% (95% confidence interval [CI], 30.96%-48.15%) with the highest prevalence in Europe and Asia, followed by North America. The current MAFLD Definition only accounted for 81.59% (95% CI, 66.51%-90.82%) of NAFLD diagnoses. Patients had increased odds of being diagnosed with MAFLD compared with NAFLD (odds ratio, 1.37; 95% CI, 1.16-1.63; P < .001). Imaging modality resulted in a significantly higher odds of being diagnosed with MAFLD compared with NAFLD, but not biopsy. MAFLD was significantly associated with males, higher body mass index, hypertension, diabetes, lipids, transaminitis, and greater fibrosis scores compared with NAFLD.

CONCLUSIONS

There were stark differences in the prevalence and risk factors between MAFLD and NAFLD. However, in the use of the MAFLD Definition, a greater emphasis on the management of concomitant metabolic diseases and a collaborative effort is required to explore the complex pathophysiologic mechanisms underlying the disease.

Association between metabolic dysfunction-associated fatty liver disease and supraventricular and ventricular tachyarrhythmias in patients with type 2 diabetes

BACKGROUND

Currently, it remains uncertain whether metabolic dysfunction-associated fatty liver disease (MAFLD) is associated with increased risk of supraventricular and ventricular tachyarrhythmias in people with type 2 diabetes mellitus (T2DM).

METHODS

We retrospectively examined the data of 367 ambulatory patients with T2DM who underwent 24-hour Holter monitoring between 2015 and 2022 for clinical indications, and who did not have pre-existing permanent atrial fibrillation (AF), kidney failure or known liver diseases. Paroxysmal supraventricular tachycardia (PSVT), paroxysmal AF and episodes of ventricular tachyarrhythmias (i.e., presence of ventricular tachycardia, >30 premature ventricular complexes per hour, or both) were recorded. The presence and severity of MAFLD was diagnosed by ultrasonography and fibrosis-4 (FIB-4) index.

RESULTS

Patients with T2DM who had MAFLD (n = 238) had a significantly greater prevalence of PSVT (51.7% vs. 38.8%), paroxysmal AF (6.3% vs. 1.3%) and combined ventricular tachyarrhythmias (31.9% vs. 20.2%) compared to their counterparts without MAFLD (n = 129). MAFLD was significantly associated with a greater than two-fold risk of having PSVT (adjusted-odds ratio [OR] 2.04, 95% confidence interval 1.04-4.00) or ventricular tachyarrhythmias (adjusted-OR 2.44, 95%CI 1.16-5.11), after adjusting for age, sex, smoking, alcohol intake, diabetes-related factors, comorbidities, medication use and left ventricular ejection fraction on echocardiography. The risk of supraventricular and ventricular tachyarrhythmias was even greater amongst patients with MAFLD and FIB-4 ≥ 1.3.

CONCLUSIONS

In ambulatory patients with T2DM, the presence and severity of MAFLD was strongly associated with an increased risk of supraventricular and ventricular arrhythmias on 24-hour Holter monitoring.

Serum Fatty Acid Composition Balance by Fuzzy C-Means Method in Individuals with or without Metabolic Dysfunction-Associated Fatty Liver Disease

Circulating fatty acid composition is assumed to play an important role in metabolic dysfunction-associated fatty liver disease (MAFLD) pathogenesis. This study aimed to investigate the association between the overall balance of serum fatty acid composition and MAFLD prevalence. This cross-sectional study involved 400 Japanese individuals recruited from a health-screening program. We measured fatty acids in serum lipids using gas chromatography-mass spectrometry. The serum fatty acid composition balance was evaluated using fuzzy c-means clustering, which assigns individual data points to multiple clusters and calculates the percentage of data points belonging to multiple clusters, and serum fatty acid mass%. The participants were classified into four characteristic subclasses (i.e., Clusters 1, 2, 3, and 4), and the specific serum fatty acid composition balance (i.e., Cluster 4) was associated with a higher MAFLD prevalence. We suggest that the fuzzy c-means method can be used to determine the circulating fatty acid composition balance and highlight the importance of focusing on this balance when examining the relationship between MAFLD and serum fatty acids.

NAFLD VS MAFLD. The evidence-based debate has come. Time to change?

Non-alcoholic fatty liver disease (NAFLD) affects one-third of the world's adult population and is linked to metabolic syndrome. It can progress to steatohepatitis, cirrhosis and hepatocellular carcinoma. During the last four decades, it has been the subject of exhaustive research in multiple aspects to define its epidemiology, pathophysiological mechanisms and therapy. In 2020, a group of international experts proposed the change of name to metabolic-associated fatty liver disease (MAFLD) with the main objective of making it an inclusive diagnosis prioritizing metabolic abnormalities. However, the change in terminology included the modification of the diagnostic criteria allowing the non-exclusion of other concomitant liver diseases such as alcohol liver disease, and chronic hepatitis B or C. The proposal precipitated a wave of debates among experts based on theoretical opinions on the desirability of the rapid adoption of the new terminology. But it also precipitated a wave of epidemiological and clinical studies which, two years later, have provided clinical evidence on the differences and similarities of the two entities, specially, those that could be considered for future refinements of the diagnostic criteria of MAFLD. Likewise, this evidence may contribute to deciding the time of adoption of this terminology. In this text, we discuss, in general terms, important aspects of the clinical evidence that has been generated to date in cross-sectional and longitudinal studies focusing on clinical characteristics and outcomes, mainly on all-cause and specific mortality of MAFLD.

Immunotherapy for nonalcoholic fatty liver disease-related hepatocellular carcinoma: Lights and shadows

About one-fourth of adults globally suffer from nonalcoholic fatty liver disease (NAFLD), which is becoming a leading cause of chronic liver disease worldwide. Its prevalence has rapidly increased in recent years, and is projected to increase even more. NAFLD is a leading cause of hepatocellular carcinoma (HCC), the sixth-most prevalent cancer worldwide and the fourth most common cause of cancer-related death. Although the molecular basis of HCC onset in NAFLD is not completely known, inflammation is a key player. The tumor microenvironment (TME) is heterogeneous in patients with HCC, and is characterized by complex interactions between immune system cells, tumor cells and other stromal and resident liver cells. The etiology of liver disease plays a role in controlling the TME and modulating the immune response. Markers of immune suppression in the TME are associated with a poor prognosis in several solid tumors. Immunotherapy with immune checkpoint inhibitors (ICIs) has become the main option for treating cancers, including HCC. However, meta-analyses have shown that patients with NAFLD-related HCC are less likely to benefit from therapy based on ICIs alone. Conversely, the addition of an angiogenesis inhibitor showed better results regarding the objective response rate and progression-free survival. Adjunctive diagnostic and therapeutic strategies, such as the application of novel biomarkers and the modulation of gut microbiota, should be considered in the future to guide personalized medicine and improve the response to ICIs in patients with NAFLD-related HCC.

Diagnostic scores and scales for appraising Nonalcoholic fatty liver disease and omics perspectives for precision medicine

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is a rising epidemic burden affecting around 25% of the global population. Liver biopsy remains the reference for NAFLD. However, the application of several scales and clinical algorithms have been proposed to diagnose NAFLD using prediction questions and blood biomarkers. This review presents a summarized of the currently available and emerging diagnostic biomarkers and scores used to assess NAFLD.

RECENT FINDINGS

The limitations of liver biopsy have fostered the development of alternative noninvasive strategies, which have been an area of intensive investigation over the past years. Diagnostic scores for NAFLD have shown to be a good alternative for disease diagnosis and prognosis due to a suitable applicability, good inter-laboratory reproducibility and widespread potential availability with reasonable costs.

SUMMARY

The growing NAFLD pandemic urges clinicians to seek alternatives for screening, early diagnosis, and follow-up, especially for those with contraindications for liver biopsy. New promising noninvasive biomarkers and techniques have been developed, evaluated and assessed, including diagnostic biomarkers scores. Moreover, multiomics markers panels involving phenotype, genotype, microbiome and clinical characteristics from patients will facilitate the diagnosis, stratification and prognosis of NAFLD patients with precision medicine approaches.

MAFLD and CKD: An Updated Narrative Review

Accumulating evidence now indicates that non-alcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease observed in clinical practice worldwide, is independently associated with an increased risk of incident chronic kidney disease (CKD). Given that NAFLD is linked to insulin resistance, obesity and type 2 diabetes mellitus, an international panel of experts have recently proposed a name change from NAFLD to metabolic associated fatty liver disease (MAFLD). Since the diagnostic criteria for NAFLD and MAFLD are different, observational studies assessing the potential concordance (or even superiority) of MAFLD, compared with NAFLD, in detecting patients at increased risk of hepatic and extra-hepatic complications (including CKD) are required. Hence, in the last two years, some observational studies have investigated the potential relationship between MAFLD and CKD. The result is that, at present, evidence regarding the concordance or even superiority of MAFLD, compared with NAFLD, in detecting patients at higher risk of CKD is still preliminary, although some data indicate that MAFLD identifies patients with CKD as accurately as NAFLD. In this narrative review, we will discuss: (a) the epidemiological evidence assessing the association between NAFLD and risk of incident CKD, (b) the epidemiological data investigating the association between MAFLD and risk of CKD and (c) the biological mechanisms underlying the association between NAFLD/MAFLD and CKD.

From MAFLD to hepatocellular carcinoma and everything in between

Metabolic (dysfunction) associated fatty liver disease (MAFLD), previously known as non-alcoholic fatty liver disease, is the most common cause of chronic liver disease worldwide. Many risk factors contribute to the pathogenesis of MAFLD with metabolic dysregulation being the final arbiter of its development and progression. MAFLD poses a substantial economic burden to societies, which based on current trends is expected to increase over time. Numerous studies have addressed various aspects of MAFLD from its risk associations to its economic and social burden and clinical diagnosis and management, as well as the molecular mechanisms linking MAFLD to end-stage liver disease and hepatocellular carcinoma. This review summarizes current understanding of the pathogenesis of MAFLD and related diseases, particularly liver cancer. Potential therapeutic agents for MAFLD and diagnostic biomarkers are discussed.

Non-Alcoholic Fatty Liver Disease and Risk of Macro- and Microvascular Complications in Patients with Type 2 Diabetes

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. To date, NAFLD is the most frequent chronic liver disease seen day by day in clinical practice across most high-income countries, affecting nearly 25–30% of adults in the general population and up to 70% of patients with T2DM. Over the last few decades, it clearly emerged that NAFLD is a “multisystemic disease” and that the leading cause of death among patients with NAFLD is cardiovascular disease (CVD). Indeed, several observational studies and some meta-analyses have documented that NAFLD, especially its advanced forms, is strongly associated with fatal and non-fatal cardiovascular events, as well as with specific cardiac complications, including sub-clinical myocardial alteration and dysfunction, heart valve diseases and cardiac arrhythmias. Importantly, across various studies, these associations remained significant after adjustment for established cardiovascular risk factors and other confounders. Additionally, several observational studies and some meta-analyses have also reported that NAFLD is independently associated with specific microvascular conditions, such as chronic kidney disease and distal or autonomic neuropathy. Conversely, data regarding a potential association between NAFLD and retinopathy are scarce and often conflicting. This narrative review will describe the current evidence about the association between NAFLD and the risk of macro- and microvascular manifestations of CVD, especially in patients with T2DM. We will also briefly discuss the biological mechanisms underpinning the association between NAFLD and its advanced forms and macro- and microvascular CVD.