Sarcopenia is associated with severe liver fibrosis in patients with non-alcoholic fatty liver disease

Association of sarcopenia assessed by CT/MRI with treatment response and clinical outcomes in noncirrhotic primary biliary cholangitis patients

BACKGROUND AND OBJECTIVE

Sarcopenia is a common complication in patients with cirrhosis. However, research on sarcopenia in patients with noncirrhotic primary biliary cholangitis (PBC) is limited. This study aimed to investigate the prevalence of sarcopenia and the associations between concomitant sarcopenia and the biochemical response to ursodeoxycholic acid (UDCA) treatment and clinical outcomes in patients with noncirrhotic PBC.

METHODS

This retrospective study enrolled consecutive patients whose baseline visits occurred between January 2009 and December 2023. Sarcopenia was assessed via pretreatment CT or MRI at the mid-L3 level through the skeletal muscle index (SMI). Baseline characteristics, response rate after UDCA administration, liver-related events were compared. And baseline liver and plasma C-reactive protein (CRP) and IL-6 levels in a subset of patients were also evaluated.

RESULTS

A total of 164 patients were included and sarcopenia was identified in 66 (40.2 %) patients. The median duration of follow-up was 4.75 (1.71, 6.40) years. The PBC patients with sarcopenia had a lower biochemical response rate (45.9 % vs. 65.9 %; P = 0.014) after 12 months of UDCA treatment and a higher incidence of liver-related events (24.2 % vs. 11.2 %, P = 0.027) during follow-up. Furthermore, higher levels of baseline CRP and IL-6 in the plasma and liver were also observed(P < 0.05).

CONCLUSIONS

Sarcopenia was highly prevalent in patients with noncirrhotic PBC. Concomitant sarcopenia may adversely affect the biochemical response to UDCA treatment and the occurrence of liver-related adverse events in PBC patients without cirrhosis.

Metabolic dysfunction-associated steatotic liver disease: A story of muscle and mass

Skeletal muscle alterations (SMA) are increasingly recognized as both contributors and consequences of metabolic dysfunction-associated steatotic liver disease (MASLD), affecting disease progression and outcomes. Sarcopenia is common in patients with MASLD, with a prevalence ranging from 20% to 40% depending on the population and diagnostic criteria used. In advanced stages, such as metabolic dysfunction-associated steatohepatitis and fibrosis, its prevalence is even higher. Sarcopenia exacerbates insulin resistance, systemic inflammation, and oxidative stress, all of which worsen MASLD. It is an independent risk factor for fibrosis progression and poor outcomes including mortality. Myosteatosis refers to the abnormal accumulation of fat within muscle tissue, leading to decreased muscle quality. Myosteatosis is prevalent (> 30%) in patients with MASLD, especially those with obesity or type 2 diabetes, although this can vary with the imaging techniques used. It reduces muscle strength and metabolic efficiency, further contributing to insulin resistance and is usually associated with advanced liver disease, cardiovascular complications, and lower levels of physical activity. Altered muscle metabolism, which includes mitochondrial dysfunction and impaired amino acid metabolism, has been reported in metabolic syndromes, including MASLD, although its actual prevalence is unknown. Altered muscle metabolism limits glucose uptake and oxidation, worsening hyperglycemia and lipotoxicity. Reduced muscle perfusion and oxygenation due to endothelial dysfunction and systemic metabolic alterations are common in MASLD associated with comorbidities, such as obesity, hypertension, and atherosclerosis. It decreases the muscle capacity for aerobic metabolism, leading to fatigue and reduced physical activity in patients with MASLD, aggravating metabolic dysfunction. Various SMA in MASLD worsen insulin resistance and hepatic fat accumulation, may accelerate progression to fibrosis and cirrhosis, and increase the risk of cardiovascular disease and mortality. Management strategies for SMA include resistance training, aerobic exercise, and nutritional support (e.g., high-protein diets, vitamin D, and omega-3 fatty acids), which are essential for mitigating skeletal muscle loss and improving outcomes. However, pharmacological agents that target the muscle and liver (such as glucagon-like peptide-1 receptor agonists) show promise but have not yet been approved for the treatment of MASLD.

Unraveling the Metabolic Pathways Between Metabolic-Associated Fatty Liver Disease (MAFLD) and Sarcopenia

Metabolic-Associated Fatty Liver Disease (MAFLD) is a public health concern that is constantly expanding, with a fast-growing prevalence, and it affects about a quarter of the world's population. This condition is a significant risk factor for cardiovascular, hepatic, and oncologic diseases, such as hypertension, hepatoma, and atherosclerosis. Sarcopenia was long considered to be an aging-related syndrome, but today, it is acknowledged to be secondarily related to chronic diseases such as metabolic syndrome, cardiovascular conditions, and liver diseases, among other comorbidities associated with insulin resistance and chronic inflammation, besides inactivity and poor nutrition. The physiopathology involving MAFLD and sarcopenia has still not been solved. Inflammation, oxidative stress, mitochondrial dysfunction, and insulin resistance seem to be some of the keys to this relationship since this hormone target is mainly the skeletal muscle. This review aimed to comprehensively discuss the main metabolic and physiological pathways involved in these conditions. MAFLD and sarcopenia are interconnected by a complex network of pathophysiological mechanisms, such as insulin resistance, skeletal muscle tissue production capacity, chronic inflammatory state, oxidative stress, and mitochondrial dysfunction, which are the main contributors to this relationship. In addition, in a clinical analysis, patients with sarcopenia and MAFLD manifest more severe hepatitis fibrosis when compared to patients with only MAFLD. These patients, with both disorders, also present clinical improvement in their MAFLD when treated for sarcopenia, reinforcing the association between them. Lifestyle changes accompanied by non-pharmacological interventions, such as dietary therapy and increased physical activity, undoubtedly improve this scenario.

Association of ultrasound signs of sarcopenia with serum ferritin levels and hepatic indices like NFS and FIB-4 in NAFLD patients

INTRODUCTION

Non-alcoholic fatty liver disease is one of the most common chronic diseases all around the world, which significantly correlates with metabolic disorders and inflammatory cycles. Sarcopenia is a decrease in the mass of skeletal muscles interacting with factors such as inflammatory processes and chronic diseases. It can also lead to the aggravation of chronic diseases.

METHOD

The study population was randomly selected and entered into the research based on exclusion and inclusion criteria. Non-alcoholic fatty liver disease was confirmed in all members of the study population by ultrasound. Patients' serum ferritin level was assessed, and their NFS and Fib 4 scores were calculated. Sarcopenia was diagnosed by measuring the thickness of the rectus femoris by ultrasonography. The correlation between these variables was evaluated and analyzed by statistical software.

RESULTS

According to statistical analysis, there is a significant association between the serum ferritin level and sarcopenia (P-value < 0.001). Besides, there is a significant association between NFS, Fib4, and sarcopenia (P-value = 0.024, 0.000).

CONCLUSION

This research's results reflect the correlation between serum ferritin and sarcopenia; however, it cannot conclude a cause-and-effect relationship between these variables.

Effectiveness and risks of dapagliflozin in treatment for metabolic dysfunction-associated steatotic liver disease with type 2 diabetes: a randomized controlled trial

Introduction

Pharmacotherapy for metabolic dysfunction-associated steatotic liver disease (MASLD) is still under development and has not been fully established. For patients with MASLD and type 2 diabetes, treatment with antidiabetic drugs, including sodium-glucose cotransporter 2 (SGLT2) inhibitors, is recommended, with vitamin E supplementation when treatment efficacy is insufficient. The benefits and risks of SGLT2 inhibitors for MASLD with type 2 diabetes have not been thoroughly investigated.

Objective

This prospective randomized controlled trial aimed to elucidate the effectiveness and risks of the SGLT2 inhibitor dapagliflozin in comparison with vitamin E in patients with MASLD and comorbid type 2 diabetes.

Methods

The trial enrolled 24 patients with MASLD and comorbid type 2 diabetes, who were assigned to receive either dapagliflozin (5 mg/day) or vitamin E (150 mg/day) for 24 weeks. The primary outcomes included serum levels of AST, ALT, γ-GT, and type IV collagen, and the FIB-4 index. The secondary outcomes were BMI, HbA1c and serum ferritin levels, lipid profile, body composition assessed using InBody, and hepatic fat content and fibrosis evaluated with FibroScan. Adverse events were monitored throughout the study period.

Results

Both groups demonstrated significant reductions in serum AST and ALT levels but intergroup differences were not significant. The dapagliflozin group showed additional benefits, with significant decreases in BMI and HbA1c, γ-GT, ferritin, LDL cholesterol, and body fat levels, indicating improved glycemic control and lipid profile. Dapagliflozin administration was associated with a significant decline in the skeletal muscle index, indicating a risk of muscle loss absent in the vitamin E group. This reduction in muscle mass is clinically significant as it suggests a potential risk of worsened overall survival with dapagliflozin treatment.

Conclusion

This study indicates that dapagliflozin provides several metabolic benefits in patients with MASLD and comorbid type 2 diabetes, including reductions in the levels of liver enzymes and body fat, but the observed decrease in muscle mass suggests a potential adverse effect on long-term survival outcomes. Muscle mass should be monitored in patients receiving dapagliflozin therapy to mitigate the risk of sarcopenia progression and ensure a comprehensive approach to MASLD management.

Clinical trial registration

https://jrct.niph.go.jp/re/reports/detail/81182, identifier jRCT1031180386.

The prevalence of nonalcoholic fatty liver disease in people living with HIV: a systematic review and meta-analysis

BACKGROUND

Owing to long-term antiretroviral therapy (ART), the incidence of non-HIV-related chronic diseases is increasing, and liver disease is the leading cause of increased AIDS mortality. Moreover, the prevalence of NAFLD and liver fibrosis has been reported to vary widely across regions and studies. There is no precise description of the trend and characteristics of NAFLD in PLWH. Here, we aimed to explore the prevalence and outcomes of NAFLD in people living with HIV (PLWH).

METHODS

The PubMed, Web of Science, Embase, and Cochrane Library databases were searched on August 15, 2023, for studies that evaluated the prevalence of NAFLD or liver fibrosis among PLWH. The meta-synthesized effects of NAFLD and liver fibrosis were the primary outcomes, and potential moderators were the secondary outcomes. The meta-analysis of the combined event rate (ER) and random effects was conducted on the basis of the number of individuals with NAFLD, the number of individuals with liver fibrosis, and the total sample size.

RESULTS

Of the 3520 studies identified, 41 studies were eligible for the meta-analysis. The results revealed that the combined ERs of NAFLD and liver fibrosis were 0.38 (95% CI: 0.33-0.43, p < 0.01) and 0.25 (95% CI: 0.18-0.32, p < 0.01), respectively.

CONCLUSIONS

This meta-analysis provided empirical evidence that the prevalence of NAFLD and liver fibrosis in PLWH is greater than that in the general population, which requires sufficient attention. In the HIV population, noninvasive imaging to monitor NAFLD changes should be strengthened, and a high TG level might be an early predictive indicator for HIV-associated fatty liver disease; however, large-scale prospective clinical research data are still needed for further validation and evaluation.

Impact of segmental body composition on metabolic dysfunction-associated fatty liver disease in Chinese children

Purpose

This study aimed to assess the relationship between regional body composition and metabolic dysfunction-associated fatty liver disease (MAFLD) in Chinese children.

Methods

In this study, 1399 children aged 7-14 years were included. Liver steatosis was assessed using the controlled attenuation parameter (CAP) measured through Fibroscan. MAFLD is defined as the presence of liver steatosis along with either overweight/obesity, prediabetes/diabetes, or at least two metabolic index abnormalities. Regression analyses were applied to assess the relationship between regional body composition and MAFLD in children. Subgroup analyses were performed based on sex and weight.

Results

The participants had a mean age of 9 years, with 52.11% being boys. Among them, 134 (9.57%) were diagnosed with MAFLD, and 17 (1.22%) had severe fatty liver disease. We found an inverse correlation between the muscle percentage in each region and MAFLD, with the extremities demonstrating the most significant negative correlation (OR: 0.732; 95% CI: 0.634-0.844). Conversely, regional fat was positively associated with MAFLD, with the strongest correlation found in the upper limbs (OR: 3.104; 95% CI: 2.023-4.764). Subgroup analyses showed similar results.

Conclusion

The decrease in regional muscle percentage, particularly in the limbs, along with the increase in regional fat percentage, especially in the upper limbs, is associated with a higher probability of developing MAFLD in prepubertal children. Additional prospective studies are needed to strengthen and validate these findings.

Least significant change with repeat bioelectrical impedance analysis measurements in children with metabolic dysfunction-associated steatotic liver disease: A descriptive cohort study

BACKGROUND

Bioelectrical impedance is used clinically to assess body composition. To determine true (rather than chance/measurement error) change in bioelectrical impedance analysis measurements over time, it is necessary to know their least significant change. Least significant change represents values exceeding the 95% prediction interval of the precision error of repeat measurements. The least significant change of repeat bioelectrical impedance analysis measurements in children with obesity and metabolic dysfunction-associated steatotic liver disease is currently unknown.

METHODS

This is a prospective, single-center, descriptive cohort study in youth 6-20 years of age with obesity and metabolic dysfunction-associated steatotic liver disease. Two same-day bioelectrical impedance analysis measurements were performed on a multifrequency, octopolar device (InBody 370). Fat mass and fat-free mass were adjusted for age using respective indices (dividing by height squared). Fasting status was determined by patient report. Descriptive statistics (medians with interquartile ranges and means with standard deviations and proportions) were used; the least significant change between repeat measurements with precision interval was calculated.

RESULTS

We recruited 43 patients (81% male; 33% Hispanic; median age: 14 years [interquartile range: 11-16]; median body mass index z score: 2.31 [interquartile range: 2.84-2.65]). A total of 60% were fasting, for a median of 12 h. The least significant change of fat mass index was 0.5 (precision interval: -0.4 to 0.5) kg/m2, fat-free mass index was 0.3 (precision interval: -0.3 to 0.3) kg/m2, and body fat percent was 1.5% (precision interval: -1.3 to 1.50). Fasting status affected least significant change measurements.

CONCLUSION

In youth with obesity and metabolic dysfunction-associated steatotic liver disease, repeat bioelectrical impedance analysis measurements beyond least significant change and precision interval determined in this study likely represent true changes in body composition over time, vs measurement error.

Dietary antioxidant capacity and sarcopenia: A study from US population

OBJECTIVES

To explore how dietary antioxidant capacity (DAC) affects sarcopenia in American adults and further evaluate the impact of meal timing and antioxidant-rich foods.

METHODS

This analysis used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018. The main exposure variables were DAC (Total, Breakfast, Lunch, Dinner, Breakfast & Lunch, Breakfast & Dinner and Lunch & Dinner), and specific antioxidant components (vitamins A, vitamins E, selenium, total carotenoids, zinc, and selenium). The outcome was sarcopenia and its components. Associations were evaluated using weighted generalized linear models and restricted cubic spline regression (RCS). Models were adjusted for demographic, lifestyle, and health factors.

RESULTS

Among 9,436 NHANES participants, representing 111.5 million noninstitutionalized US residents (mean age, 38.9 ± 11.5 years; 50.9% female; 34.33% non-Hispanic white; 21.26% non-Hispanic black; and 20.01% Mexican American). There was a negative correlation between Total DAC and sarcopenia. According to meal time, eating more antioxidant foods at lunch time could reduce the risk of sarcopenia. According to the classification of food, it was further found that DAC in oils had a protective effect on sarcopenia. Increased intake of vitamins A, E, and selenium was associated with a lower sarcopenia risk. Subgroup analysis additionally observed a significant interaction between drinking status and DAC.

CONCLUSIONS

A higher DAC diet may protect against sarcopenia, especially through the intake of vitamins A, E, selenium, and oils during lunch. This increased DAC is also linked to improved handgrip strength, a critical factor in sarcopenia. However, further research is required to validate these associations and explore additional influencing factors.

Correlation of sarcopenia with progression of liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease: a study from two cohorts in China and the United States

OBJECTIVE

The objective of this study was to investigate the association between sarcopenia and liver fibrosis in patients aged 18-59 years with metabolic dysfunction-associated steatotic liver disease (MASLD) and to assess the potential of sarcopenia as a risk factor for the progression of liver fibrosis.

METHODS

The study included 821 patients with MASLD in the US cohort and 3,405 patients with MASLD in the Chinese cohort. Liver controlled attenuation parameters (CAP) and liver stiffness measurements (LSM) were assessed by vibration-controlled transient elastography (VCTE) to evaluate the extent of hepatic steatosis and fibrosis. Sarcopenia was assessed by measuring appendicular skeletal muscle mass (ASM) and calculating ASMI. To analyze the relationship between sarcopenia, ASMI, and liver fibrosis, logistic regression models, multivariate-adjusted models, and restricted cubic spline (RCS) models were employed, with stratification and interaction analyses.

RESULTS

The results demonstrated that patients with sarcopenia exhibited a markedly elevated risk of significant liver fibrosis, advanced liver fibrosis, and cirrhosis compared to those without sarcopenia in both cohorts. After adjusting for confounding variables, sarcopenia was identified as an independent risk factor for the progression of liver fibrosis in patients with MASLD. A significant negative correlation was observed between ASMI and the severity of liver fibrosis, with a progressive reduction in the risk of liver fibrosis associated with increasing ASMI. Additionally, a non-linear feature was evident in some liver fibrosis indicators. Subgroup analysis further corroborated the finding that the harmful effect of sarcopenia on liver fibrosis was consistent across all identified subgroups.

CONCLUSION

Sarcopenia may be associated with the progression of liver fibrosis in patients with MASLD. Monitoring ASMI may assist in identifying individuals at an elevated risk of liver fibrosis in MASLD patients.

Longitudinal Links between Changes in Body Composition and Liver Disease Severity in Children and Adolescents with Metabolic Dysfunction-Associated Steatotic Liver Disease

OBJECTIVE

To investigate the relationship between longitudinal changes in body composition and liver disease severity in children with metabolic dysfunction-associated steatotic liver disease (MASLD).

STUDY DESIGN

This longitudinal, single-center, retrospective analysis included patients aged <20 years followed for MASLD who had had ≥2 bioelectrical impedance analyses (BIAs) performed. MASLD regression was defined as alanine aminotransferase (ALT) normalization or a decrease of >50% from baseline. Fat and skeletal muscle mass were adjusted for size by calculating respective indices (dividing by height2). Logistic and linear regressions were used to determine the independent relationship between changes in body composition over time and serological markers of liver disease severity.

RESULTS

We included 258 patients (75% male, 50% Hispanic) with a median age of 14 years (IQR, 11-16 years) at the time of first BIA. Median body mass index (BMI) z-score at baseline was 2.33 (IQR, 2.04-2.62). Median time from first to last BIA was 12 months (IQR, 6-24 months). A decrease in fat mass index was independently associated with reductions in ALT and gamma glutamyl transferase and increased odds of MASLD regression (OR; 0.55; P < .001). Fat mass index reduction was superior to BMI z-score in predicting MASLD regression. Change in skeletal muscle mass index was not associated with change in ALT or gamma glutamyl transferase.

CONCLUSIONS

Changes in fat mass, not skeletal muscle mass, are associated with serological markers of liver injury in youth with MASLD. Fat mass changes outperform BMI z-score changes in predicting MASLD regression. BIA can serve as an adjunct biomarker of liver disease progression.

Efficiency of Skeletal Muscle Mass/Weight Measurement for Distinguishing Metabolic Dysfunction-Associated Steatotic Liver Disease: A Prospective Analysis Using InBody Bioimpedance Devices

BACKGROUND/OBJECTIVES

Metabolic dysfunction-associated steatotic liver disease (MASLD) is diagnosed when hepatic steatosis is proven by imaging and one of the five cardiometabolic criteria is present. The relationship between MASLD and body composition components has recently received increased research attention. However, the five cardiometabolic criteria do not include components of body composition. This study aimed to identify significant body composition factors associated with MASLD in patients undergoing health checkups.

METHODS

This study included a cohort of 6599 examinees who participated in a health check-up conducted between 2022 and 2023, and their data were prospectively analyzed. The inclusion criteria were undergoing abdominal ultrasonography, alcohol consumption <30 g/day for males or <20 g/day for females, and one of the five cardiometabolic criteria.

RESULTS

Finally, 3864 examinees were enrolled. In total, 1133 (51.8%) males and 454 (27.1%) females had MASLD. Sarcopenia was present in only 0.62% of males and 0.66% of females with MASLD. The MASLD group had significantly lower skeletal muscle mass/weight (SMM/WT) values than the non-MASLD group. Multivariate analysis revealed that SMM/WT was independently associated with MASLD.

CONCLUSIONS

SMM/WT was significantly associated with MASLD. Therefore, muscle mass assessment using SMM/WT may be a potential marker for diagnosing MASLD.

Hepatic glucose production rises with the histological severity of metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (MASH) are associated with a high prevalence of type 2 diabetes (T2D). Individuals with MASLD exhibit insulin resistance (IR) and hyperglycemia, but it is unclear whether hepatic glucose production (HGP) is increased with MASLD severity. We evaluated HGP in a cohort of histologically characterized individuals with MASL/MASH using stable isotope infusion (6,6-2H2-glucose, U-2H5-glycerol) and liver-specific genome-scale metabolic models (GEMs). Tracer-measured HGP is increased with liver fibrosis and inflammation, but not steatosis, and is associated with lipolysis and IR. The GEM-derived gluconeogenesis is elevated due to high glucogenic/energy metabolite uptakes (lactate, glycerol, and free fatty acid [FFA]), and the expression of insulin action genes (IRS1, IRS2, and AKT2) is reduced in MASH with fibrosis F2-F4, with/without T2D, suggesting these as putative mechanisms for increased fasting HGP and hyperglycemia. In conclusion, elevated HGP, lipolysis, and IR help to explain the mechanisms for the increased risk of hyperglycemia and T2D in MASH.

Effects of ipragliflozin on skeletal muscle adiposity in patients with diabetes and metabolic dysfunction-associated steatotic liver disease

Objective Myosteatosis affects the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) and may be a potential therapeutic target. This study aimed to examine the effects of ipragliflozin on myosteatosis in patients with type 2 diabetes mellitus (T2D) and MASLD. Methods Patients were treated with ipragliflozin (IPR group) or a control (CTR group) for 72 weeks in a randomized trial. Changes in myosteatosis of the lumbar skeletal muscles were evaluated using computed tomography (CT). The response of myosteatosis to treatment and the baseline characteristics of the patients were analyzed. Patients 44 participants (IPR group, 23; CTR group, 21) with MASLD complicated by T2D Results Myosteatosis increased in the CTR group (n=23) but remained unchanged in the IPR group (n=21). The changes were apparent at 24 weeks (P=0.004), but were not significant after 24 weeks. A hierarchical cluster analysis was performed to identify clusters with and without improvement in myosteatosis. The clusters with decreasing intramuscular adipose tissue content (IMAC) at 48 and 72 weeks were not treated, but they had lower visceral fat area and severe liver steatosis at baseline. Improvements in glycemic control and resistance to decreasing abdominal skeletal muscle area from baseline to 24 weeks affected the decrease in IMAC at 48 and 72 weeks. Conclusion Ipragliflozin had a limited effect on skeletal muscle adiposity in patients with T2D and MASLD. Regardless of the treatment, a specific phenotype of adiposity and hepatic steatosis before treatment is associated with the long-term outcomes of myosteatosis. Maintaining skeletal muscle mass and better glycemic control during treatment are essential for the future improvement of myosteatosis.

Relationship between sarcopenia and metabolic dysfunction-associated steatotic liver disease (MASLD): A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Metabolic dysfunction-associated steatotic liver disease (MASLD) formerly known as Nonalcoholic fatty liver disease (NAFLD) is a common chronic disease. Identifying MASLD risk factors could help early intervention and reduce the burden of the disease. Previous studies investigated the association between sarcopenia and NAFLD. Several trials were published after the last meta-analysis with indecisive results. This is an updated meta-analysis which aims to assess the association between sarcopenia, MASLD, and MASLD-related fibrosis.

MATERIALS AND METHODS

Relevant trials published on PubMed, Web of Science, Scopus, and Cochrane Library databases until October 2022 were included. We included studies in which skeletal mass index (SMI) or sarcopenia was compared between patients with and without NAFLD now MASLD. Also, studies comparing fibrosis between MASLD patients with and without sarcopenia were included. Data were pooled as odds ratios (ORs) and 95 % confidence intervals (CIs) using Review Manager Software.

RESULTS

A total of 25 studies were included. The incidence of sarcopenia was significantly higher in MASLD than controls (OR, 1.25; 95 % CI, 1.08-1.44; P = 0.003). SMI odds showed no significant difference between MASLD patients and controls (OR, 1.02; 95 % CI, 0.91-1.15; P = 0.7). MASLD patients with sarcopenia had higher odds of fibrosis than MASLD patients without sarcopenia (OR, 1.49; 95 % CI, 1.03-2.14; P = 0.03).

CONCLUSIONS

Sarcopenia increased MASLD's probability and was associated with a higher probability of liver fibrosis in MASLD patients. However, SMI had no predictive value of MASLD occurrence.

Sarcopenia as a Risk Factor for Mortality in NAFLD: How Should We Diagnose It?

OBJECTIVES

Sarcopenia increases the risk of nonalcoholic steatohepatitis (NASH) and cirrhosis in patients with nonalcoholic fatty liver disease (NAFLD). Subsequently, poorly managed NAFLD can result in adverse health outcomes. Lifestyle interventions are effective for both NAFLD and sarcopenia; however, diagnosis of sarcopenia in this population is not well defined. This review aimed to examine current methods to diagnose sarcopenia in NAFLD patients.

METHODS

MEDLINE, EMBASE, and CINAHL databases were searched for articles published until July 2023 using the terms "Non-alcoholic fatty liver disease," "NAFLD," "fatty liver," "sarcopenia," and "myoatrophy." Studies were excluded if they included pediatric populations, did not diagnose both sarcopenia and NAFLD, or included patients with alternate causes of liver disease.

RESULTS

Twenty studies, predominantly from Asian countries (14 [70.0%]), involving 68 848 participants (45.5% females) were included. In 15 studies, most participants had a BMI > 25 kg/m2. Heterogeneity in the tools used to diagnose NAFLD was identified, with abdominal ultrasound being the most commonly used. European, Asian, and Australasian Sarcopenia Working Groups had differing diagnostic definitions of sarcopenia. Of the three potential diagnostic elements of sarcopenia (muscle mass, strength, function), all studies measured muscle mass, commonly through bioelectrical impedance analysis (12 [60.0%]). Seven studies (35.0%) measured muscle strength, with the majority (n = 6) utilizing hand grip strength. Four (20.0%) measured muscle function, through gait speed or a timed up-and-go test.

CONCLUSIONS

The lack of standardization in sarcopenia diagnosis for NAFLD patients is concerning. A consistent definition is necessary to prevent this comorbidity from being overlooked, improve care, and outcomes.

Clinical Characteristics of Sarcopenia in Nonalcoholic Fatty Liver Disease: A Systemic Scoping Review

INTRODUCTION

This systematic scoping review aimed to synthesize existing research findings on the clinical manifestations in patients with nonalcoholic fatty liver disease (NAFLD) and sarcopenia.

METHODS

Adhering to scoping review guidelines, we comprehensively searched five databases for literature on sarcopenia's clinical manifestations in NAFLD patients from December 2013 to December 2023, meticulously compiling and synthesizing the findings.

RESULTS

A total of 312 articles were identified, with 9 studies included in the final review. Of these, 90% were cross-sectional investigations, with 70% from Asian cohorts. Comparative analysis between patients solely afflicted with NAFLD and those additionally experiencing sarcopenia revealed discernible trends. Individuals with both conditions tended to be older, have a higher body mass index, and show a higher prevalence among females, underscoring the influence of unhealthy lifestyles and obesity. Furthermore, comorbidities like metabolic syndrome, hypertension, and diabetes have been implicated in sarcopenia manifestation among NAFLD patients. Nonetheless, the lack of standardized diagnostic criteria and patterns poses an ongoing clinical challenge for this subgroup.

CONCLUSIONS

Our review highlights distinct clinical characteristics evident in NAFLD patients with sarcopenia. However, comprehensive investigations remain scarce, impeding accurate early detection and intervention. Future research should prioritize bridging these gaps and fostering enhanced clinical management strategies.

The prevalence and effects of sarcopenia in patients with metabolic dysfunction-associated steatotic liver disease (MASLD): A systematic review and meta-analysis

BACKGROUND AND AIMS

Sarcopenia is a common complication in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). However, the prevalence and its impact on the survival of sarcopenia in patients with MASLD is unknown. In this study, we aimed to assess the prevalence and effects of sarcopenia in patients with MASLD.

METHODS

Systematic review and meta-analysis of full texts of relevant studies were searched from inception until June 12, 2024 in five databases (PubMed, Cochrane Library, Embase, Web of Science, and the China National Knowledge Infrastructure). Next, we assessed the prevalence of sarcopenia in MASLD, and calculated the ORs and HRs between sarcopenia and MASLD based on the adjusted data from individual studies. Statistical analyses were performed using Stata 11.0.

RESULTS

Of the 2984 records considered, 29 studies recruiting 63,330 patients were included. The pooled prevalence of sarcopenia in patients with MASLD was 23.5% overall (95% CI; 19.1%-27.9%, I2 = 99.6%), and was higher in Asian patients, male, cross-sectional studies, when BIA were employed to measure muscle mass, one criterion of diagnosis sarcopenia, MASLD was diagnosed employing MRI, and moderate-quality studies. Sarcopenia was associated with MASLD patients (adjusted odds ratio [aOR] 2.08, 95% CI 1.58-2.74, I2 = 93.6%) with similar findings in subgroups stratified by age, study design, methods for measuring muscle mass, assessment method to detect sarcopenia, and study quality. The association between all-cause mortality further supports the association between sarcopenia and poor prognosis with MASLD (aHR 1.59, 95% CI 1.33-1.91, I2 = 0%).

CONCLUSIONS

Sarcopenia was strongly associated with MASLD progression and was a risk factor not only for MASLD pathogenesis but was also markedly correlated with MASLD-associated mortality.

Systemic impacts of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) on heart, muscle, and kidney related diseases

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is the most common liver disorder worldwide, with an estimated global prevalence of more than 31%. Metabolic dysfunction-associated steatohepatitis (MASH), formerly known as non-alcoholic steatohepatitis (NASH), is a progressive form of MASLD characterized by hepatic steatosis, inflammation, and fibrosis. This review aims to provide a comprehensive analysis of the extrahepatic manifestations of MASH, focusing on chronic diseases related to the cardiovascular, muscular, and renal systems. A systematic review of published studies and literature was conducted to summarize the findings related to the systemic impacts of MASLD and MASH. The review focused on the association of MASLD and MASH with metabolic comorbidities, cardiovascular mortality, sarcopenia, and chronic kidney disease. Mechanistic insights into the concept of lipotoxic inflammatory "spill over" from the MASH-affected liver were also explored. MASLD and MASH are highly associated (50%-80%) with other metabolic comorbidities such as impaired insulin response, type 2 diabetes, dyslipidemia, hypertriglyceridemia, and hypertension. Furthermore, more than 90% of obese patients with type 2 diabetes have MASH. Data suggest that in middle-aged individuals (especially those aged 45-54), MASLD is an independent risk factor for cardiovascular mortality, sarcopenia, and chronic kidney disease. The concept of lipotoxic inflammatory "spill over" from the MASH-affected liver plays a crucial role in mediating the systemic pathological effects observed. Understanding the multifaceted impact of MASH on the heart, muscle, and kidney is crucial for early detection and risk stratification. This knowledge is also timely for implementing comprehensive disease management strategies addressing multi-organ involvement in MASH pathogenesis.

The Expression of Genes Related to Reverse Cholesterol Transport and Leptin Receptor Pathways in Peripheral Blood Mononuclear Cells Are Decreased in Morbid Obesity and Related to Liver Function

Obesity is frequently accompanied by non-alcoholic fatty liver disease (NAFLD). These two diseases are associated with altered lipid metabolism, in which reverse cholesterol transport (LXRα/ABCA1/ABCG1) and leptin response (leptin receptor (Ob-Rb)/Sam68) are involved. The two pathways were evaluated in peripheral blood mononuclear cells (PBMCs) from 86 patients with morbid obesity (MO) before and six months after Roux-en-Y gastric bypass (RYGB) and 38 non-obese subjects. In the LXRα pathway, LXRα, ABCA1, and ABCG1 mRNA expressions were decreased in MO compared to non-obese subjects (p < 0.001, respectively). Ob-Rb was decreased (p < 0.001), whereas Sam68 was increased (p < 0.001) in MO. RYGB did not change mRNA gene expressions. In the MO group, the LXRα pathway (LXRα/ABCA1/ABCG1) negatively correlated with obesity-related variables (weight, body mass index, and hip), inflammation (C-reactive protein), and liver function (alanine-aminotransferase, alkaline phosphatase, and fatty liver index), and positively with serum albumin. In the Ob-R pathway, Ob-Rb and Sam68 negatively correlated with alanine-aminotransferase and positively with albumin. The alteration of LXRα and Ob-R pathways may play an important role in NAFLD development in MO. It is possible that MO patients may require more than 6 months following RYBGB to normalize gene expression related to reverse cholesterol transport or leptin responsiveness.

Quick and easy assessment of sarcopenia in cirrhosis: Can ultrasound be the solution?

Cirrhosis is frequently associated with sarcopenia, with reported rates of over 80% in patients with decompensated alcohol-related liver disease. Sarcopenia negatively impacts the prognosis of cirrhotic patients and affects the response to treatment of patients with hepatocellular carcinoma (HCC). For these reasons, identifying an easy-to-perform method to assess sarcopenia in is a key element in the optimization of care in this patient population. Assessment of muscle mass by computed tomography is considered the standard of care for the diagnosis of sarcopenia, but exposure to radiation and high costs limit its application in this setting, especially for repeated assessments. We believe that ultrasound, a cheap and harmless technique also used for HCC screening in cirrhotic patients, could have an expanding role in the diagnosis and follow-up of sarcopenia in these patients.

Prevalence and outcome of sarcopenia in non-alcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) includes a spectrum of conditions, progressing from mild steatosis to advanced fibrosis. Sarcopenia, characterized by decreased muscle strength and mass, shares common pathophysiological traits with NAFLD. An association exists between sarcopenia and increased NAFLD prevalence. However, data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.

AIM

To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.

METHODS

We conducted a comprehensive search for relevant studies in MEDLINE, Embase, and Scopus from their inception to June 2023. We included studies that focused on patients with NAFLD, reported the prevalence of sarcopenia as the primary outcome, and examined secondary outcomes, such as liver fibrosis and other adverse events. We also used the Newcastle-Ottawa scale for quality assessment.

RESULTS

Of the 29 studies included, the prevalence of sarcopenia in NAFLD varied widely (1.6% to 63.0%), with 20 studies reporting a prevalence of more than 10.0%. Substantial heterogeneity was noted in the measurement modalities for sarcopenia. Sarcopenia was associated with a higher risk of advanced fibrosis (odd ratio: 1.97, 95% confidence interval: 1.44-2.70). Increased odds were consistently observed in fibrosis assessment through biopsy, NAFLD fibrosis score/body mass index, aspartate aminotransferase to alanine aminotransferase ratio, diabetes (BARD) score, and transient elastography, whereas the fibrosis-4 score showed no such association. Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis, insulin resistance, cardiovascular risks, and mortality.

CONCLUSION

This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients. The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings. This review demonstrates the multidimensional impact of sarcopenia on NAFLD, indicating its importance beyond liver-related events to include cardiovascular risks, mortality, and metabolic complications.

NAFLD Fibrosis Progression and Type 2 Diabetes: The Hepatic-Metabolic Interplay

The bidirectional relationship between type 2 diabetes and (non-alcoholic fatty liver disease) NAFLD is indicated by the higher prevalence and worse disease course of one condition in the presence of the other, but also by apparent beneficial effects observed in one, when the other is improved. This is partly explained by their belonging to a multisystemic disease that includes components of the metabolic syndrome and shared pathogenetic mechanisms. Throughout the progression of NAFLD to more advanced stages, complex systemic and local metabolic derangements are involved. During fibrogenesis, a significant metabolic reprogramming occurs in the hepatic stellate cells, hepatocytes, and immune cells, engaging carbohydrate and lipid pathways to support the high-energy-requiring processes. The natural history of NAFLD evolves in a variable and dynamic manner, probably due to the interaction of a variable number of modifiable (diet, physical exercise, microbiota composition, etc.) and non-modifiable (genetics, age, ethnicity, etc.) risk factors that may intervene concomitantly, or subsequently/intermittently in time. This may influence the risk (and rate) of fibrosis progression/regression. The recognition and control of the factors that determine a rapid progression of fibrosis (or its regression) are critical, as the fibrosis stages are associated with the risk of liver-related and all-cause mortality.

Blockade of angiotensin II modulates insulin-like growth factor 1-mediated skeletal muscle homeostasis in experimental steatohepatitis

Sarcopenia is associated with mortality in patients with nonalcoholic steatohepatitis (NASH). Angiotensin II receptor blocker (ARB) has been suggested to prevent sarcopenia, but reports on its effect on NASH-derived skeletal muscle atrophy in conjunction with insulin-like growth factor 1 (IGF-1)-mediated muscle homeostasis are few. Our aim was to examine the combined effect of the ARB losartan and IGF-1 replacement on skeletal muscle atrophy in a methionine-choline deficient (MCD) diet-fed murine steatohepatitis model. The MCD-fed mice developed steatohepatitis and skeletal muscle atrophy, as indicated by the reduction of psoas muscle mass and attenuation of forelimb and hindlimb grip strength. Significantly suppressed steatohepatitis and skeletal muscle atrophy was observed after single treatment with ARB or IGF-1, and these effects were augmented after combination treatment. Treatment with ARB and IGF-1 effectively inhibited ubiquitin proteasome-mediated protein degradation by reducing forkhead box protein O1 (FOXO1) and FOXO3a transcriptional activity in the skeletal muscle. Combined ARB and IGF-1 decreased the intramuscular expression of proinflammatory cytokines (i.e., TNFα, IL6, and IL1β) and increased the Trolox equivalent antioxidant capacity and antioxidant enzymes (CAT, GPX1, SOD2, and CYTB). This antioxidant effect was based on downregulation of NADPH oxidase (NOX) 2, normalization of mitochondrial biogenesis and dynamics. Moreover, ARB increased the hepatic and plasma IGF-1 levels and improved steatohepatitis, leading to enhanced skeletal muscle protein synthesis mediated by IGF-1/ AKT/ mechanistic target of rapamycin signaling. Collectively, combined ARB and IGF-1 replacement could be a promising new therapeutic target for NASH-derived skeletal muscle wasting.

Effects of nonalcoholic fatty liver disease on sarcopenia: evidence from genetic methods

With the aging of the population, sarcopenia has become more common. Studies have shown a broad association between liver disease and sarcopenia. However, this link remains unclear. Our study explored the link between NAFLD and sarcopenia and predicting the pathogenesis. To begin, we investigated the causal relationship and genetic correlation between them using MR and LDSC. Second, each GWAS was annotated by MAGMA. The annotated genes were analyzed for pleiotropy using the PLACO approach. Finally, functional analysis was conducted on the identified pleiotropic genes. We observed a significant genetic correlation between NAFLD and sarcopenia. Subsequently, we conducted gene-level pleiotropy analysis using PLACO and identified a total of 153 genes with pleiotropic effects. Functional analysis revealed enrichment of these genes in various tissues, including pancreas, liver, heart, blood, brain, and muscle, with involvement in cellular regulation, intracellular function, and antigen response. Moreover, our MR analysis provided evidence of a causal relationship between NAFLD and sarcopenia. Our study has discovered the genetic and causal relationships between NAFLD and sarcopenia, providing further insights into their pathophysiological mechanisms. The identification of pleiotropic genes also offers potential targets for future drug therapies aimed at controlling or treating NAFLD and sarcopenia.

Lower creatinine to cystatin C ratio is associated with an increased risk of MASLD: A cross-sectional and prospective study of 368,634 UK Biobank participants

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects many populations, and screening out the high-risk populations at an early stage is a challenge. As a sarcopenia index, the relationship between creatinine to cystatin C ratio (CCR) and MASLD remains unclear. This cross-sectional, prospective study aimed to explore the relationship between CCR and MASLD. Design Firstly, explored the correlation between CCR and MASLD in cross-sectional analyses. Then excluded the population with baseeline diagnosis of MASLD and analyzed the association with baseline CCR levels and the onset of MASLD in the population with available follow-up data. Univariate and multivariate logistic regression analyses were used to calculate odds ratios (ORs) to evaluate the association between CCR levels and MASLD.

PATIENTS AND MEASUREMENTS

This study included 368,634 participants from the UK Biobank for cross-sectional and prospective analyses. The demographic characteristics and laboratory measurements of all participants were obtained from the UK Biobank. MASLD was diagnosed according to the multi-society consensus nomenclature. Hepatic steatosis was defined as FLI  ≥60.

RESULTS

We grouped the study participants according to CCR tertiles. In cross-sectional analyses, participants in CCR tertile 1 had the highest MASLD risk (OR: 1.070, 95% CI: 1.053-1.088, p < .001). And the similar association was observed in the prospective analyses (CCR tertile 1 OR: 1.340, 95% CI: 1.077-1.660, p = .009; CCR tertile 2 OR: 1.217, 95% CI: 1.021-1.450, p = .029, respectively). After stratification by gender, the significant association between CCR and the onset of MASLD was only observed in males (CCR tertile 1 OR: 1.639, 95% CI: 1.160-2.317, p = .005; CCR tertile 2 OR: 1.322, 95% CI: 1.073-1.628, p = .005, respectively).

CONCLUSION

Our results indicated that lower CCR was significantly associated with higher risk of MASLD, based on which predictive models can be developed to screen populations at high risk of developing MASLD.

What Does Sarcopenia Have to Do with Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. As the second stage of developing steatosis, nonalcoholic hepatitis (NASH) carries the risk of fibrosis, cirrhosis, and hepatocellular carcinoma. Sarcopenia is defined as a condition characterized by a decrease in muscle mass and functional decline. Both NAFLD and sarcopenia are global problems. The pathophysiological mechanisms that link the two entities of the disease are insulin resistance, inflammation, nutritional deficiencies, impairment of myostatin and adiponectin, or physical inactivity. Furthermore, disorders of the gut-liver axis appear to induce the process of developing NAFLD and sarcopenia. The correlations between NAFLD and sarcopenia appear to be bidirectional, so the main objective of the review was to determine the cause-and-effect relationship between the two diseases.

Restoring skeletal muscle mass as an independent determinant of liver fat deposition improvement in MAFLD

AIMS

Cross-sectional studies have demonstrated the association of skeletal muscle mass with metabolic-associated fatty liver disease (MAFLD), while longitudinal data are scarce. We aimed to explore the impact of changes in relative skeletal muscle mass on the MAFLD treatment response.

METHODS

MAFLD patients undergoing magnetic resonance imaging-based proton density fat fraction for liver fat content (LFC) assessments and bioelectrical impedance analysis before and after treatment (orlistat, meal replacement, lifestyle modifications) were enrolled. Appendicular muscle mass (ASM) was adjusted by weight (ASM/W).

RESULTS

Overall, 256 participants were recruited and divided into two groups: with an ASM/W increase (n=166) and without an ASM/W increase (n=90). There was a great reduction in LFC in the group with an ASM/W increase (16.9% versus 8.2%, P < 0.001). However, the change in LFC in the group without an ASM/W increase showed no significant difference (12.5% versus 15.0%, P > 0.05). △ASM/W Follow-up-Baseline [odds ratio (OR)=1.48, 95% confidence interval (CI) 1.05-2.07, P = 0.024] and △total fat mass (OR=1.45, 95% CI 1.12-1.87, P = 0.004) were independent predictors for steatosis improvement (relative reduction of LFC ≥ 30%). The subgroup analysis showed that, despite without weight loss, decrease in HOMA-IR (OR=6.21, 95% CI 1.28-30.13, P=0.023), △total fat mass Baseline -Follow-up (OR=3.48, 95% CI 1.95-6.21, P <0.001 and △ASM/W Follow-up-Baseline (OR=2.13, 95% CI 1.12-4.05, P=0.022) independently predicted steatosis improvement.

CONCLUSIONS

ASM/W increase and loss of total fat mass benefit the resolution of liver steatosis, independent of weight loss for MAFLD.

NAFLD Associates with Sarcopenia Defined by Muscle Mass and Slow Walking Speed: A Cross-Sectional Analysis from the Framingham Heart Study

Sarcopenia is associated with NAFLD. It is unknown if the association is explained by shared risk factors. Our study sought to investigate the association between liver fat and sarcopenia in our cohort. Liver fat was measured on CT between 2008 and 2011. We excluded heavy alcohol use and missing covariates. Muscle mass in a subset (n = 485) was measured by 24 h urinary creatinine. Physical function was defined by h strength and walking speed. Sarcopenia was defined as low muscle mass and/or low physical function. We created multivariable-adjusted regression models to evaluate cross-sectional associations between liver fat and low muscle mass, grip strength, and walking speed. The prevalence of hepatic steatosis was 30% (n = 1073; 58.1% women; mean age 65.8 ± 8.6 years). There was a significant positive association between liver fat and muscle mass in linear regression models. The association was not significant after adjusting for BMI. The odds of sarcopenia increased by 28% for each SD in liver fat (OR 1.28; 95% CI 1.02, 1.60) and persisted after accounting for confounders in multivariable-adjusted models (OR 1.30, 95% CI 1.02, 1.67). Further studies are needed to determine if there is a causal relationship between liver fat and sarcopenia and whether treatment of sarcopenia improves liver fat.

A nomogram based on psoas muscle index predicting long-term cirrhosis incidence in non-cirrhotic patients with HBV-related acute‑on‑chronic liver failure

There is a lack of scoring system to predict the occurrence of cirrhosis in individuals with acute-on-chronic liver failure (ACLF) in the absence of cirrhosis. The goal of this study was to develop a psoas muscle index (PMI)-based nomogram for cirrhosis risk in non-cirrhotic patients with HBV-related ACLF. We included 274 non-cirrhotic HBV-ACLF patients who were randomly assigned to training and validation groups. Logistic analyses were performed to identify risk factors for cirrhosis. A nomogram was then constructed. The predictive performance of the nomogram was assessed using the area under the receiver operating characteristic curve (AUROC), calibration curve, and decision curve analysis (DCA). During the 360-day follow-up, 44.5% (122/274) of non-cirrhotic HBV-ACLF patients developed cirrhosis. A higher PMI at the L3 level was correlated with a decreased risk of long-term cirrhosis occurrence (OR 0.677, 95% CI 0.518-0.885, P = 0.004). The nomogram incorporating PMI, age, neutrophil-to-lymphocyte ratio (NLR), and international normalized ratio (INR), indicated satisfactory predictive performance for cirrhosis risk stratification in ACLF population. The nomograms had an AUROC of 0.812 (95% CI 0.747-0.866) and 0.824 (95% CI 0.730-0.896) in the training and validation cohorts, respectively. The calibration curves displayed excellent predictive accuracy of the nomogram in both sets. In both cohorts, the DCA verified the nomogram's clinical efficacy. In non-cirrhotic HBV-ACLF patients, a greater PMI appears to protect against long-term cirrhosis occurrence. Strong predictive performance has been demonstrated by PMI-based nomograms in assessing the likelihood of 1-year cirrhosis in those with HBV-ACLF.

Deep Learning for Computed Tomography Assessment of Hepatic Fibrosis and Cirrhosis: A Systematic Review

Studies were identified using deep learning artificial intelligence methods for the analysis of computed tomography images in the assessment of hepatic fibrosis and cirrhosis. A systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies protocol to evaluate the accuracy of deep learning algorithms for this objective (PROSPERO CRD 42023366201). A literature search was conducted on Medline, Embase, Web of Science, and IEEE Xplore databases. The search was conducted with a timeline from January 1, 2000,through November 13, 2022. Our search resulted in 3877 studies for screening, which yielded 6 studies meeting our inclusion criteria. All studies were retrospective. Three studies performed internal validation, and 2 studies performed external validation. Four studies used image classification algorithms, whereas 2 studies used image segmentation algorithms to derive volumetric measurements of the liver and spleen. Accuracy of the algorithms was variable in diagnosing significant and advanced fibrosis and cirrhosis, with the area under the curve ranging from 0.63 to 0.97. Deep learning algorithms using computed tomography images have the potential to classify fibrosis stages. Heterogeneity in cohorts and methodologies limits the generalizability of these studies.

Nonalcoholic Fatty Liver Disease as a Systemic Disease and the Need for Multidisciplinary Care

Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease, and there has been a rapid increase in cases worldwide. NAFLD is rapidly becoming the leading cause of hepatocellular carcinoma and is also associated with an increased risk of cardiovascular disease or exacerbation of other organ diseases, thus posing a significant health problem from both a medical and a socioeconomic perspective. NAFLD is a systemic disease and requires the involvement of numerous medical professionals. Multidisciplinary collaboration, in which different professionals within different specialties come together and work together toward a common goal, supports better patient care by integrating perspectives of multiple experts and facilitating the exchange of opinions. Due to the large number of potential patients, gastroenterologists and hepatologists cannot manage the patients alone, and collaboration between specialists in various fields, including family doctors, dentists, nutritionists, and pharmacists is required for treatment of NAFLD. This review will discuss NAFLD from the perspective of various specialties and introduce multidisciplinary collaboration.

Impact of skeletal muscle mass evaluating methods on severity of metabolic associated fatty liver disease in non-elderly adults

The study aimed to explore the relationships of skeletal muscle mass with disease severity in metabolic-associated fatty liver disease (MAFLD) patients with different methods. Consecutive subjects undergoing bioelectrical impedance analysis were included. The steatosis grade and liver fibrosis were evaluated by MRI-derived proton density fat fraction and two-dimensional shear wave elastography. The appendicular skeletal muscle mass (ASM) was adjusted by height2 (ASM/H2), weight (ASM/W) and BMI (ASM/BMI). Overall, 2223 subjects (50·5 %, MAFLD; 46·9 %, male) were included, with the mean age 37·4 ± 10·6 years. In multivariate logistic regression analysis, the subjects with the lowest quartile (Q1) of ASM/W or ASM/BMI had higher risk ratios for MAFLD (OR (95 % CI) in male: 2·57 (1·35, 4·89), 2·11(1·22, 3·64); in female: 4·85 (2·33, 10·01), 4·81 (2·52, 9·16), all P < 0·05, all for Q1 v. Q4). The MAFLD patients with lower quartiles of ASM/W had the higher risk OR for insulin resistance (IR), both in male and female (2·14 (1·16, 3·97), 4·26 (1·29, 14·02) for Q4 v. Q1, both P < 0·05). While the significant OR were not observed when ASM/H2 and ASM/BMI were used. There were significant dose-dependent associations between decreased ASM/W as well as ASM/BMI and moderate-severe steatosis (2·85(1·54, 5·29), 1·90(1·09, 3·31), both P < 0·05) in male MAFLD patients. In conclusion, ASM/W is superior to ASM/H2 and ASM/BMI in predicting the degree of MAFLD. A lower ASM/W is associated with IR and moderate-severe steatosis in non-elderly male MAFLD.

Non-alcoholic fatty liver disease and socioeconomic determinants in an Iranian cohort study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is widespread worldwide. On the other hand, social inequality and socioeconomic status (SES) can affect all aspects of health. Therefore, this study aimed to investigate the relationship between SES indicators and NAFLD.

METHODS

This was a cross-sectional study using data from the registration phase of the Hoveyzeh Cohort Study, which included 10,009 individuals aged 35-70 years from May 2016 to August 2018. Fatty liver disease was determined based on Fatty Liver Index (FLI). The crude and adjusted odds ratios were calculated by logistic regression analysis to estimate associations between the fatty liver index and SES after controlling the potential confounders.

RESULTS

According to the FLI index, there were 2,006 people with fatty liver (28%) and 5,246 people without fatty liver (72%). Several 4496 people (62%) were women. The chi-square test showed significant relationships between the educational level and skill level (P < 0.001), the wealth index (P < 0.001), and Townsend Index (P < 0.001) with fatty liver index. In multivariable analysis, after adjustment for age, sex, physical activity, smoking, type of residence, calorie intake, dyslipidemia, skill level, and diabetes, the wealth index (p < 0.001) was positively associated with the fatty liver index. Besides, a reverse and significant association was seen between the Townsend index and the fatty liver index(p < 0.001). In contrast, no significant associations were seen between gender and educational level with the fatty liver index.

CONCLUSIONS

A more vulnerable SES is associated with NAFLD. Fatty liver index and socioeconomic indicators can be powerful monitoring tools to monitor health differences in diagnosing NAFLD.

Association between handgrip strength, nonalcoholic fatty liver disease, advanced hepatic fibrosis and its modifiers: Evidence from the NHANES database of the USA

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) and advanced hepatic fibrosis (AHF) have been associated with sarcopenia. However, modifiers of this association have been less studied.

METHODS

This study used data from the NHANES database 2011-2014 of the USA. Adults aged 18 years or older, had complete information of handgrip strength test and NAFLD and AHF status were eligible for inclusion. NAFLD was defined using the Fatty Liver Index (FLI). AHF was defined using the NAFLD fibrosis score (NFS). Univariate and multivariate logistic regression were performed to determine the associations between the study variables and prevalent NAFLD and AHF.

RESULTS

A total of 19 931 participants were selected from the 2011-2014 NHANES database. The multivariate analysis showed that stronger grip strength was significantly and independently associated with decreased odds for NAFLD (tertile 2: adjusted odd ratio [aOR]: 0.41, 95% confidence interval [CI]: 0.29-0.59; tertile 3: aOR: 0.11, 95% CI: 0.05-0.24) and AHF (tertile 2: aOR: 0.66, 95% CI: 0.46-0.94; tertile 3: aOR: 0.28, 95% CI: 0.12-0.63). In stratified analyses, strongest grip strength was significantly associated with reduced odds for NAFLD regardless of age, body mass index, and having diabetes or not. Strongest grip strength was associated with reduced odds for NAFLD in individuals who had moderate to ideal physical activity (aOR: 0.31).

CONCLUSIONS

Grip strength has an inverse association with prevalent NAFLD and AHF in the US population, which appears to be modified by physical activity level. Future prospective cohort studies are needed to clarify the role of physical activity in modifying the risks.

Sarcopenia, sarcopenic obesity and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), sarcopenia and sarcopenic obesity (SO) are highly prevalent conditions that may coexist, especially in the aging population, without any approved pharmacologic treatment for all of them. There are multiple pathophysiologic mechanisms suggested to explain an association between NAFLD and sarcopenia or SO, including alterations in the adipokines, cytokines, hepatokines and myokines, which may interplay with other factors, such as aging, diet and physical inactivity. In clinical terms, most observational studies support an association between NAFLD and sarcopenia or SO; importantly, there are few cohort studies indicating higher mortality in patients with NAFLD and sarcopenia. Their association also bears some treatment considerations: for example, pioglitazone or vitamin E, suggested as off label treatment for selected patients with nonalcoholic steatohepatitis, may be recommended in the coexistence of sarcopenia or SO, since limited evidence did not show adverse effects of them on sarcopenia and abdominal obesity. In this review, evidence linking sarcopenia and SO with NAFLD is summarized, with a special focus on clinical data. A synopsis of the major pathophysiological links between NAFLD and sarcopenia/SO is initially presented, followed by selected clinical studies and, finally, treatment considerations in patients with NAFLD and sarcopenia or SO are discussed.

Associations between muscle mass, strength, and performance and non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a rising global health issue. The influence of muscle in its pathophysiology has recently gained attention. Our aim was to investigate the association of low muscle mass, strength, and performance with the presence and severity of NAFLD.

METHODS

Patients with metabolic syndrome followed in an outpatient clinic, were consecutively included, between April 1st and December 31st, 2019. Abdominal ultrasound for the diagnosis of NAFLD, NAFLD fibrosis score (NFS) and Fibrosis-4 Index (FIB-4) for determination of significant fibrosis, dual-energy X-ray absorptiometry for calculation of skeletal muscle index (SMI = appendicular skeletal mass / weight x100) and sarcopenic index (SI = appendicular skeletal mass / Body Mass Index), and the Short Physical Performance Battery for muscle strength and performance assessment were performed. Sarcopenia was defined as low muscle strength and low SMI or SI.

RESULTS

A total of 157 patients were included, of which 68.8% had NAFLD, 66.2% low SMI, 50.3% low SI, 16.6% low performance and 11.5% low strength. In patients with NAFLD, prevalence of significant fibrosis by NFS was 15.7%. Low SMI was associated with presence of NAFLD when adjusted for age, sex, type 2 diabetes mellitus, hypertension, and dyslipidemia, but not for body mass index and waist circumference. Low SMI, low SI, and sarcopenia were associated with significant fibrosis in univariate analysis; the small number of events precluded a multivariable analysis.

CONCLUSIONS

Low SMI was associated with NAFLD independently of demographics and comorbidities but not of other parameters of body composition. This contrasts with most studies published on this matter.

MAFLD might be better in identifying subjects with sarcopenia or cardiovascular risk than NAFLD: A nationwide study

BACKGROUND AND AIM

Clinical features of non-alcoholic fatty liver disease (NAFLD), but not fulfilling the diagnostic criteria of metabolic dysfunction-associated fatty liver disease (MAFLD), remain unclear. We investigated the risk of sarcopenia and cardiovascular disease (CVD) in MAFLD and non-metabolic risk (MR) NAFLD.

METHODS

Subjects were selected from the Korean National Health and Nutrition Examination Surveys 2008-2011. Liver steatosis was assessed using fatty liver index. Significant liver fibrosis was defined using fibrosis-4 index, categorized by age cut-offs. Sarcopenia was defined as the lowest quintile sarcopenia index. Atherosclerotic CVD (ASCVD) risk score > 10% was defined as high probability.

RESULTS

A total of 7248 subjects had fatty liver (137 with non-MR NAFLD, 1752 with MAFLD/non-NAFLD, and 5359 with overlapping MAFLD and NAFLD). In non-MR NAFLD group 28 (20.4%) had significant fibrosis. The risk of sarcopenia (adjusted odds ratio [aOR] = 2.71, 95% confidence index [CI] = 1.27-5.78) and high probability of ASCVD (aOR = 2.79, 95% CI = 1.23-6.35) was significantly higher in MAFLD/non-NAFLD group than in non-MR NAFLD group (all P < 0.05). The risk of sarcopenia and high probability of ASCVD was similar between subjects with and without significant fibrosis in non-MR NAFLD group (all P > 0.05). However, the risk was significantly higher in MAFLD group than in non-MR NAFLD group (aOR = 3.38 for sarcopenia and 3.73 for ASCVD; all P < 0.05).

CONCLUSIONS

The risks of sarcopenia and CVD were significantly higher in MAFLD group but did not differ according to fibrotic burden in non-MR NAFLD group. The MAFLD criteria might be better for identifying high-risk fatty liver disease than the NAFLD criteria.

Expression of Prostaglandin Genes and β-Catenin in Whole Blood as Potential Markers of Muscle Degeneration

Prostaglandin signaling pathways are closely related to inflammation, but also muscle regeneration and processes associated with frailty and sarcopenia, whereas β-catenin (CTNNB1 gene) as a part of Wnt signaling is also involved in the differentiation of muscle cells and fibrosis. The present study analyzed the association between selected prostaglandin pathway genes and clinical parameters in patients with sarcopenia and frailty syndrome. The present study was conducted on patients with sarcopenia, frailty syndrome, and control older patients (N = 25). Additionally, two healthy controls at the age of 25-30 years (N = 51) and above 50 years old (N = 42) were included. The expression of the PTRGER4, PTGES2 (COX2), PTGS2, and CTNNB1 genes in whole blood was checked by the qPCR method. The serum cytokine levels (IL-10, TNFα, IFN-y, IL-1α, IL-1β) in patients and controls were checked by the Q-Plex Human Cytokine Panel. The results showed a significant effect of age on PTGER4 gene expression (p = 0.01). A negative trend between the appendicular skeletal muscle mass parameter (ASSM) and the expression of PTGER4 has been noted (r = -0.224, p = 0.484). PTGES2 and PTGS2 expressions negatively correlated with creatine phosphokinase (r = -0.71, p = 0.009; r = -0.58, p = 0.047) and positively with the functional mobility test timed up and go scale (TUG) (r = 0.61, p = 0.04; r = 0.63, p = 0.032). In the older control group, a negative association between iron levels and the expression of PTGS2 (r = -0.47, p = 0.017) was observed. A similar tendency was noted in patients with sarcopenia (r = -0.112, p = 0.729). A negative trend between appendicular skeletal muscle mass (ASMM) and PTGER4 seems to confirm the impairment of muscle regeneration associated with sarcopenia. The expression of the studied genes revealed a trend in associations with the clinical picture of muscular dystrophy and weakening patients. Perhaps PTGS2 and PTGES2 is in opposition to the role of the PTGER4 receptor in muscle physiology. Nevertheless, further, including functional studies is needed.

Epigenetic Regulation in Lean Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most prominent cause of chronic liver disease worldwide, is a rapidly growing epidemic. It consists of a wide range of liver diseases, from steatosis to nonalcoholic steatohepatitis, and predisposes patients to liver fibrosis, cirrhosis, and even hepatocellular carcinoma. NAFLD is strongly correlated with obesity; however, it has been extensively reported among lean/nonobese individuals in recent years. Although lean patients demonstrate a lower prevalence of diabetes mellitus, central obesity, dyslipidemia, hypertension, and metabolic syndrome, a percentage of these patients may develop steatohepatitis, advanced liver fibrosis, and cardiovascular disease, and have increased all-cause mortality. The pathophysiological mechanisms of lean NAFLD remain vague. Studies have reported that lean NAFLD demonstrates a close association with environmental factors, genetic predisposition, and epigenetic modifications. In this review, we aim to discuss and summarize the epigenetic mechanisms involved in lean NAFLD and to introduce the interaction between epigenetic patterns and genetic or non genetic factors. Several epigenetic mechanisms have been implicated in the regulation of lean NAFLD. These include DNA methylation, histone modifications, and noncoding-RNA-mediated gene regulation. Epigenetics is an area of special interest in the setting of lean NAFLD as it could provide new insights into the therapeutic options and noninvasive biomarkers that target this under-recognized and challenging disorder.

GDF8 Contributes to Liver Fibrogenesis and Concomitant Skeletal Muscle Wasting

Patients with end-stage liver disease exhibit progressive skeletal muscle atrophy, highlighting a negative crosstalk between the injured liver and muscle. Our study was to determine whether TGFβ ligands function as the mediators. Acute or chronic liver injury was induced by a single or repeated administration of carbon tetrachloride. Skeletal muscle injury and repair was induced by intramuscular injection of cardiotoxin. Activin type IIB receptor (ActRIIB) ligands and growth differentiation factor 8 (Gdf8) were neutralized with ActRIIB-Fc fusion protein and a Gdf8-specific antibody, respectively. We found that acute hepatic injury induced rapid and adverse responses in muscle, which was blunted by neutralizing ActRIIB ligands. Chronic liver injury caused muscle atrophy and repair defects, which were prevented or reversed by inactivating ActRIIB ligands. Furthermore, we found that pericentral hepatocytes produce excessive Gdf8 in injured mouse liver and cirrhotic human liver. Specific inactivation of Gdf8 prevented liver injury-induced muscle atrophy, similar to neutralization of ActRIIB ligands. Inhibition of Gdf8 also reversed muscle atrophy in a treatment paradigm following chronic liver injury. Direct injection of exogenous Gdf8 protein into muscle along with acute focal muscle injury recapitulated similar dysregulated muscle regeneration as that observed with liver injury. The results indicate that injured liver negatively communicate with the muscle largely via Gdf8. Unexpectedly, inactivation of Gdf8 simultaneously ameliorated liver fibrosis in mice following chronic liver injury. In vitro, Gdf8 induced human hepatic stellate (LX-2) cells to form a septa-like structure and stimulated expression of profibrotic factors. Our findings identified Gdf8 as a novel hepatomyokine contributing to injured liver-muscle negative crosstalk along with liver injury progression.

Lean nonalcoholic fatty liver disease and sarcopenia

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases in the world. The risk factor for NAFLD is often considered to be obesity, but it can also occur in people with lean type, which is defined as lean NAFLD. Lean NAFLD is commonly associated with sarcopenia, a progressive loss of muscle quantity and quality. The pathological features of lean NAFLD such as visceral obesity, insulin resistance, and metabolic inflammation are inducers of sarcopenia, whereas loss of muscle mass and function further exacerbates ectopic fat accumulation and lean NAFLD. Therefore, we discussed the association of sarcopenia and lean NAFLD, summarized the underlying pathological mechanisms, and proposed potential strategies to reduce the risks of lean NAFLD and sarcopenia in this review.

Sarcopenia in chronic viral hepatitis: From concept to clinical relevance

Although the frequency of metabolic risk factors for cirrhosis and hepatocellular carcinoma (HCC) is increasing, chronic hepatitis B (CHB) and chronic hepatitis C (CHC) remain the most relevant risk factors for advanced liver disease worldwide. In addition to liver damage, hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are associated with a myriad of extrahepatic manifestations including mixed cryoglobulinaemia, lymphoproliferative disorders, renal disease, insulin resistance, type 2 diabetes, sicca syndrome, rheumatoid arthritis-like polyarthritis, and autoantibody production. Recently, the list has grown to include sarcopenia. Loss of muscle mass or muscle function is a critical feature of malnutrition in cirrhotic patients and has been found in approximately 23.0%-60.0% of patients with advanced liver disease. Nonetheless, among published studies, there is significant heterogeneity in the aetiologies of hepatic diseases and measurement methods used to determine sarcopenia. In particular, the interaction between sarcopenia, CHB and CHC has not been completely clarified in a real-world setting. Sarcopenia can result from a complex and multifaceted virus-host-environment interplay in individuals chronically infected with HBV or HCV. Thus, in the present review, we provide an overview of the concept, prevalence, clinical relevance, and potential mechanisms of sarcopenia in patients with chronic viral hepatitis, with an emphasis on clinical outcomes, which have been associated with skeletal muscle loss in these patients. A comprehensive overview of sarcopenia in individuals chronically infected with HBV or HCV, independent of the stage of the liver disease, will reinforce the necessity of an integrated medical/nutritional/physical education approach in the daily clinical care of patients with CHB and CHC.

SHRSP5/Dmcr rats fed a high-fat and high-cholesterol diet develop disease-induced sarcopenia as nonalcoholic steatohepatitis progresses

BACKGROUND

Secondary sarcopenia develops as a result of a bedridden state and illnesses, such as cachexia, liver disease, and diabetes. However, there is a lack of animal models to investigate the underlying mechanisms and potential treatments for secondary sarcopenia. Recently, secondary sarcopenia has been associated with the prognosis of nonalcoholic steatohepatitis. This study aimed to investigate whether stroke-prone spontaneously hypertensive rat 5 (SHRSP5/Dmcr) which developed severe nonalcoholic steatohepatitis by a high-fat and high-cholesterol (HFC; containing 2% cholic acid) diet is a useful model of secondary sarcopenia.

METHODS

SHRSP5/Dmcr rats were divided into 6 groups fed with a Stroke-Prone (SP: normal chow) or HFC diets for different periods (4, 12, and 20 weeks), and WKY/Izm rats were divided into 2 groups fed an SP or HFC diet. Body weight, food intake, and muscle force were measured weekly for all rats. After the end of the diet period, skeletal muscle strength evoked by electrical stimulation was recorded, blood was collected, and organ weight was measured. The sera were used for biochemical analysis and the organs were used for histopathological analysis.

RESULTS

SHRSP5/Dmcr rats fed an HFC diet developed nonalcoholic steatohepatitis, and their skeletal muscles, especially fast muscles, showed atrophy, indicating that muscle atrophy is aggravated by the progression of nonalcoholic steatohepatitis. In contrast, WKY/Izm rats fed an HFC diet did not exhibit sarcopenia.

CONCLUSIONS

This study suggests that SHRSP5/Dmcr rats could be a useful novel model for investigate the mechanism of secondary sarcopenia disorder associated with nonalcoholic steatohepatitis.

Clinics in Liver Disease: Update on Nonalcoholic Steatohepatitis: Sarcopenia and Nonalcoholic Fatty Liver Disease

Dual diagnoses of sarcopenia and nonalcoholic fatty liver disease (NAFLD) increase the risk of all cause mortality and severe liver disease, regardless of nationality. General agreement about diagnostic criteria for sarcopenia includes loss of skeletal muscle mass, weakness, and reduced physical performance. Histopathology demonstrates loss of type 2 muscle fibers, more than type 1 fibers and myosteatosis, a risk factor for severe liver disease. Low skeletal mass and NAFLD are inversely related; the mechanism is through decreased insulin signaling and insulin resistance, critical for metabolic homeostasis. Weight loss, exercise, and increased protein intake have been effective in reducing NAFLD and sarcopenia.

Association of Hepatic Steatosis with Adipose and Muscle Mass and Distribution in Children

Background: Pediatric studies have shown associations between hepatic steatosis and total body fat, visceral fat, and lean mass. However, these associations have not been assessed simultaneously, leaving their relative importance unknown. Objective: To evaluate associations between hepatic steatosis and total-body adiposity, visceral adiposity, and lean mass in children. Method: In children at risk for fatty liver, hepatic steatosis, adipose, and lean mass were estimated with magnetic resonance imaging and dual-energy X-ray absorptiometry. Results: Two hundred twenty-seven children with mean age 12.1 years had mean percent body fat of 38.9% and mean liver fat of 8.4%. Liver fat was positively associated with total-body adiposity, visceral adiposity, and lean mass (P < 0.001), and negatively associated with lean mass percentage (P < 0.001). After weight adjustment, liver fat was only positively associated with measures of central adiposity (P < 0.001). Visceral adiposity also had the strongest association with liver fat (P < 0.001). Conclusions: In children, hepatic steatosis is more strongly associated with visceral adiposity than total adiposity, and the association of lean mass is not independent of weight or fat mass. These relationships may help guide the choice of future interventions to target hepatic steatosis.

Osteosarcopenia in NAFLD/MAFLD: An Underappreciated Clinical Problem in Chronic Liver Disease

Chronic liver disease (CLD), including non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), affects a significant portion of the population worldwide. NAFLD is characterised by fat accumulation in the liver, while NASH is associated with inflammation and liver damage. Osteosarcopenia, which combines muscle and bone mass loss, is an emerging clinical problem in chronic liver disease that is often underappreciated. The reductions in muscle and bone mass share several common pathophysiological pathways; insulin resistance and chronic systemic inflammation are the most crucial predisposing factors and are related to the presence and gravity of NAFLD and to the worsening of the outcome of liver disease. This article explores the relationship between osteosarcopenia and NAFLD/MAFLD, focusing on the diagnosis, prevention and treatment of this condition in patients with CLD.

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

NAFLD has become a major public health problem for more than 2 decades with a growing prevalence in parallel with the epidemic of obesity and type 2 diabetes (T2D). The disease burden of NAFLD differs across geographical regions and ethnicities. Variations in prevalence of metabolic diseases, extent of urban-rural divide, dietary habits, lifestyles, and the prevalence of NAFLD risk and protective alleles can contribute to such differences. The rise in NAFLD has led to a remarkable increase in the number of cases of cirrhosis, hepatocellular carcinoma, hepatic decompensation, and liver-related mortality related to NAFLD. Moreover, NAFLD is associated with multiple extrahepatic manifestations. Most of them are risk factors for the progression of liver fibrosis and thus worsen the prognosis of NAFLD. All these comorbidities and complications affect the quality of life in subjects with NAFLD. Given the huge and growing size of the population with NAFLD, it is expected that patients, healthcare systems, and the economy will suffer from the ongoing burden related to NAFLD. In this review, we examine the disease burden of NAFLD across geographical areas and ethnicities, together with the distribution of some well-known genetic variants for NAFLD. We also describe some special populations including patients with T2D, lean patients, the pediatric population, and patients with concomitant liver diseases. We discuss extrahepatic outcomes, patient-reported outcomes, and economic burden related to NAFLD.