Lean Indian patients with non-alcoholic fatty liver disease (NAFLD) have less metabolic risk factors but similar liver disease severity as non-lean patients with NAFLD

S, Kingsley A, Thekkumkara Surendran Nair A, Gomez R, G P, Thambi T.S. A, N. S. Prevalence of Transaminitis and Metabolic Dysfunction-Associated Steatotic Liver Disease Among Young Indian Adults-A Population-Based Study

Background

Metabolic dysfunction-associated steatotic liver disease (MASLD) with onset in youth may be more consequential for adverse outcomes than that detected later in adulthood. Transaminitis in the general population is a marker of the prevalence of MASLD. There are no previous community-based studies in Indian youth assessing the prevalence of transaminitis. The purpose of this study was to find out the prevalence of transaminitis, MASLD and elevated Fibrosis-4 (FIB-4) index among young South Indian adults.

Methods

This was a cross-sectional study done over a period of 1 year from January 2022 among adults aged 18-30 years. Multistage sampling was used to recruit participants with body mass index (BMI) < 30 kg/m2 and without moderate to heavy alcohol consumption from four different sociogeographic regions. Detailed history, physical examination and investigations including liver enzymes (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]), platelet count, and metabolic workup were carried out. FIB-4 index and Nonalcoholic fatty liver disease-liver fat score (NAFLD-LFS) were calculated. LFS ≥ -0.64 was used to rule in MASLD.

Results

A total of 2373 (1170 males) participants with a mean age of 24 ± 3.5 years were included. Transaminitis (AST or ALT≥35 IU/L) was seen in 25.9% of the cohort. MASLD by NAFLD-LFS was present in 27.4% of the population. FIB-4 index ≥1.3 was found in 54 (2.27%) participants. Neck circumference and Trivandrum Medical College adiposity index were associated with transaminitis, MASLD, and elevated FIB-4. Blood pressure, triglycerides, and low-density lipoprotein cholesterol were higher, and high-density lipoprotein cholesterol was lower among participants with transaminitis, but they were not different among those with elevated FIB-4 index. BMI and waist-hip ratio were not different among participants with and those without transaminitis or MASLD.

Conclusion

There is a high prevalence of transaminitis and MASLD in community-dwelling young adult Indians. We recommend screening all young adult Indians for MASLD and transaminitis.

Central Obesity is an Independent Determinant of Advanced Fibrosis in Lean Patients With Nonalcoholic Fatty Liver Disease

Background

The current definition of lean is based on body mass index (BMI). However, BMI is an imperfect surrogate for adiposity and provides no information on central obesity (CO). Hence, we explored the differences in clinical profile and liver disease severity in lean patients with nonalcoholic fatty liver disease (NAFLD) with and without CO.

Methods

One hundred seventy lean patients with NAFLD (BMI <23 kg/m2) were divided into two groups depending upon the presence or absence of CO (waist circumference ≥80 cm in females and ≥90 cm in males). Noninvasive assessment of steatosis was done by ultrasound and controlled attenuation parameter (CAP), while fibrosis was assessed with FIB-4 and liver stiffness measurement (LSM). FibroScan-AST (FAST) score was used for non-invasive prediction of NASH with significant fibrosis.

Results

Of 170 patients with lean NAFLD, 96 (56.5%) had CO. Female gender (40.6% vs. 17.6%, P = 0.001), hypertriglyceridemia (58.3% vs. 39.2%, P = 0.01) and metabolic syndrome (23.9% vs. 4.1%, P < 0.001) were more common in the CO group. There was a poor correlation between BMI and waist circumference (r = 0.24, 95% CI: 0.09-0.38). Grade 2-3 steatosis on ultrasound was significantly more common in CO patients (30% vs. 12.3%, P = 0.007). CAP [312.5 (289.8-341) dB/m vs. 275 (248-305.1) dB/m, P = 0.002], FAST score [0.42 (0.15-0.66) vs. 0.26 (0.11-0.39), P = 0.04], FIB-4 and LSM were higher in those with CO. Advanced fibrosis was more prevalent among CO patients using FIB-4 (19.8% vs 8.1%, P = 0.03) and LSM (9.5% vs. 0, P = 0.04). CO was independently associated with advanced fibrosis after adjusting for BMI and metabolic risk factors (aOR: 3.11 (1.10-8.96), P = 0.03). Among these 170 patients, 142 fulfilled metabolic dysfunction associated steatotic liver disease (MASLD) criteria. CO was also an independent risk factor for advanced fibrosis in MASLD (3.32 (1.23-8.5), P = 0.02).

Conclusion

Lean patients with NAFLD or MASLD and CO have more severe liver disease compared to those without CO.

Risk Factors for Non-alcoholic Fatty Liver Disease from the Perspective of Medical Professionals: A Systematic Review and Expert Opinion

Background

The incidence of non-alcoholic fatty liver disease (NAFLD) has increased with the global increase in the outbreak of obesity, type 2 diabetes, and metabolic syndrome, reaching a 25% prevalence. However, there is currently no effective treatment for this disease apart from lifestyle modification. Furthermore, NAFLD commonly presents without symptoms, hence, leading to potentially severe and irreparable consequences.

Methods

This study was based on a systematic review. The search used the keywords "non-alcoholic fatty liver" and "risk factor" across the PubMed, Scopus, and Web of Science databases. First, the articles were evaluated based on their abstract and then on their full text. The risk factors were extracted from the articles and entered into the Excel form, and then a dataset was provided to the expert panel. The risk factors were investigated, and those related to NAFLD were selected.

Results

The results led to the identification of 180 risk factors in 15 categories. First, the risk factors mentioned in fewer than five articles were removed. Then, the remaining 101 risk factors were presented to the expert panel, of which 39 risk factors related to NAFLD were selected.

Conclusion

In summary, this study shows that NAFLD is caused by various factors such as metabolic syndrome, certain diseases, demographic information, specific surgeries, drug consumption, different foods and beverages, occupation, physical activity status, and socioeconomic status. Recognizing these risk factors enables doctors to make earlier diagnoses, potentially preventing disease progression. Additionally, it is possible to develop treatment strategies aimed at reducing the risk factors of the disease, which could result in fewer patients suffering from NAFLD in the future.

Long-term outcomes and risk modifiers of metabolic dysfunction-associated steatotic liver disease between lean and non-lean populations

One-third of adults across the globe exhibit metabolic dysfunction-associated steatotic liver disease (MASLD)-formerly known as nonalcoholic fatty liver disease (NAFLD). To date, MASLD is the fastest-growing etiology of chronic liver disease and hepatocellular carcinoma (HCC). Besides the population with obesity, MASLD can also be found in lean populations, accounting for 13% of the global population, especially Asians. Notably, individuals with lean MASLD face equal or higher overall mortality rates compared to their non-lean counterparts. Risk modifiers encompass advanced age, hepatic fibrosis, and type 2 diabetes mellitus (T2DM). Moreover, the population with lean MASLD is associated with an increased risk of HCC, while their non-lean counterparts are more prone to cardiovascular outcomes and T2DM. Existing evidence indicates a similar risk of liver-related events and extrahepatic cancer between the two groups. However, MASLD-related genetic variants, such as PNPLA3 and TM6SF2, did not significantly affect mortality between the two populations. Still, underreporting alcohol consumption and regional representation limits the study's comprehensiveness. Longitudinal studies and mechanistic explorations are needed to understand differences in lean versus non-lean MASLD populations. This review highlights the need for awareness and tailored interventions in managing MASLD, considering lean individuals' unique risks.

Treatment and Survival Disparities in Asian Americans With Hepatocellular Carcinoma: The Need to Disaggregate a Diverse Cohort

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in the United States and globally. The Asian American, Native Hawaiian, and Pacific Islander (AANHPI) population has often been studied as one homogenous cohort despite its heterogeneity. We aim to understand differences in treatment modality and mortality among AANHPI patients with early-stage HCC.

METHODS

The National Cancer Database was queried between 2004 and 2019. Patients with early-stage HCC eligible for liver transplantation (LT) were included. AANHPI patients were further disaggregated into subgroups, and non-Hispanic White (NHW) patients were included as reference. χ2 was used for categorical variables and the Student t test was used for continuous variables. Survival curves were generated using Kaplan-Meier estimates.

RESULTS

A total of 3039 (8.5%) AANHPI and 32,845 (91.5%) NHW were included. Among the AANHPI, 1368 (45.0%) were East Asian (EA), 1229 (40.4%) were Southeast Asian (SEA), 302 (9.9%) were South Asian (SA), and 140 (4.6%) were Native Hawaiian and other Pacific Islander (NHPI). Compared with NHW, AANHPI patients were less likely to undergo LT but had lower mortality. When disaggregated, SA patients were more likely to receive LT (HR: 2.70), and SEA (HR: 1.43) and NHPI (HR: 1.90) patients had higher mortality when compared with EA, all P<0.01.

CONCLUSIONS

AANHPI with early-stage HCC had better survival as a cohort. However, when disaggregated, there were notable disparities among different subgroups. AANHPI represents an incredibly diverse group of individuals, and it is imperative for physicians, researchers, and policy makers to appreciate the true heterogeneity of this population.

Lifestyle intervention for metabolic dysfunction-associated fatty liver disease: a 24-h integrated behavior perspective

INTRODUCTION

The prevalence, health and socioeconomic burden of metabolic dysfunction-associated fatty liver disease (MAFLD) is growing, increasing the need for novel evidence-based lifestyle approaches. Lifestyle is the cornerstone for MAFLD management and co-existing cardiometabolic dysfunction. The aim of this review was to evaluate the evidence for lifestyle management of MAFLD, with a specific lens on 24-hour integrated behaviour and provide practical recommendations for implementation of the evidence.

RESULTS

Weight loss ≥ 7-10% is central to lifestyle management; however, liver and cardiometabolic benefits are attainable with improved diet quality and exercise even without weight loss. Lifestyle intervention for MAFLD should consider an integrated '24-h' approach that is cognisant of diet, physical activity/exercise, sedentary behavior, smoking, alcohol intake and sleep. Dietary management emphasises energy deficit and improved diet quality, especially the Mediterranean diet, although sociocultural adaptations to meet preferences should be considered. Increasing physical activity and reducing sedentary behavior can prevent MAFLD, with strongest evidence in MAFLD supporting regular structured moderate-vigorous aerobic exercise for 150-240 min/week. Resistance training in addition to aerobic exercise should be considered and prioritised for those who are losing body mass via diet and/or pharmacological approaches and those with sarcopenia, to minimise bone and lean mass loss. Limited evidence suggests that sleep is important for MAFLD prevention. Emerging novel approaches to diet and exercise may address some of the key barriers to behaviour change (e.g. lack of time, access to resources and social support).

FUTURE DIRECTIONS

Large-scale multidisciplinary trials in people with MAFLD with long-term follow-up, that can be scaled up into mainstream healthcare, are required. Future management guidelines should consider the heterogeneity of MAFLD and specialised models of care that coordinate the health workforce to manage the increased and growing MAFLD population.

Impact of nomenclature as metabolic associated steatotic liver disease on steatotic liver disease prevalence and screening: a prospective population survey in Asians

BACKGROUND AND AIM

The introduction of the latest nomenclature, metabolic associated steatotic liver disease (MASLD), proposed by the multi-society without Asian society consensus statement, aims to redefine the diagnostic criteria for metabolic associated fatty liver disease (MAFLD). However, its effect on the epidemiology in Asia remains unclear.

METHOD

We conducted a population-based cross-sectional survey on fatty liver disease using multistage stratified random sampling of participants from Guangzhou, a representative area in China (ChiCTR2000033376). Demographic, socioeconomic, lifestyle, and laboratory data were collected. Hepatic steatosis and the severity of fibrosis were assessed using FibroScan.

RESULTS

A total of 7388 individuals were recruited, the proportion of which meeting the definitions for nonalcoholic fatty liver disease (NAFLD), MAFLD, and MASLD were 2359 (31.9%), 2666 (36.1%), and 2240 (30.3%), respectively. One hundred and twenty (1.6%) patients had cryptogenic SLD, and 537 (7.3%) patients were diagnosed with MetALD. MASLD did not significantly differ from NAFLD and MAFLD, except that MAFLD patients had a lower proportion of males, hypertension, and diabetes and were less likely to consume tea (P < 0.05). Both cryptogenic SLD and MASLD non-MAFLD patients exhibited milder hepatic steatosis and a lower frequency of liver injury than NAFLD, MAFLD, or MASLD patients (all P < 0.05). An increased HOMA-IR (adjusted OR: 1.33, 95% CI: 1.10-2.03) was associated with higher risk of moderate-to-severe steatosis for MASLD non-MAFLD patients, while consuming more cups of tea (P for trend = 0.015) showed inverse associations.

CONCLUSION

Irrespective of terminology used is that fatty liver disease is highly prevalent in the Han Chinese population. Differences in insulin resistance and lifestyle risk factors are associated with redefinition disparities.

Dysfunctional VLDL metabolism in MASLD

Lipidomics has unveiled the intricate human lipidome, emphasizing the extensive diversity within lipid classes in mammalian tissues critical for cellular functions. This diversity poses a challenge in maintaining a delicate balance between adaptability to recurring physiological changes and overall stability. Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), linked to factors such as obesity and diabetes, stems from a compromise in the structural and functional stability of the liver within the complexities of lipid metabolism. This compromise inaccurately senses an increase in energy status, such as during fasting-feeding cycles or an upsurge in lipogenesis. Serum lipidomic studies have delineated three distinct metabolic phenotypes, or "metabotypes" in MASLD. MASLD-A is characterized by lower very low-density lipoprotein (VLDL) secretion and triglyceride (TG) levels, associated with a reduced risk of cardiovascular disease (CVD). In contrast, MASLD-C exhibits increased VLDL secretion and TG levels, correlating with elevated CVD risk. An intermediate subtype, with a blend of features, is designated as the MASLD-B metabotype. In this perspective, we examine into recent findings that show the multifaceted regulation of VLDL secretion by S-adenosylmethionine, the primary cellular methyl donor. Furthermore, we explore the differential CVD and hepatic cancer risk across MASLD metabotypes and discuss the context and potential paths forward to gear the findings from genetic studies towards a better understanding of the observed heterogeneity in MASLD.

Exploring Fibrosis Pathophysiology in Lean and Obese Metabolic-Associated Fatty Liver Disease: An In-Depth Comparison

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-β, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.

Update in lean metabolic dysfunction-associated steatotic liver disease

BACKGROUND

A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD). They are now defined as metabolic dysfunction-associated steatotic liver disease (MASLD), which includes cardiometabolic criteria in adults. This condition, extensively studied in obese or overweight patients, constitutes around 30% of the population, with a steady increase worldwide. Lean patients account for approximately 10%-15% of the MASLD population. However, the pathogenesis is complex and is not well understood.

AIM

To systematically review the literature on the diagnosis, pathogenesis, characteristics, and prognosis in lean MASLD patients and provide an interpretation of these new criteria.

METHODS

We conducted a comprehensive database search on PubMed and Google Scholar between January 2012 and September 2023, specifically focusing on lean NAFLD, MAFLD, or MASLD patients. We include original articles with patients aged 18 years or older, with a lean body mass index categorized according to the World Health Organization criteria, using a cutoff of 25 kg/m2 for the general population and 23 kg/m2 for the Asian population.

RESULTS

We include 85 studies in our analysis. Our findings revealed that, for lean NAFLD patients, the prevalence rate varied widely, ranging from 3.8% to 34.1%. The precise pathogenesis mechanism remained elusive, with associations found in genetic variants, epigenetic modifications, and adaptative metabolic response. Common risk factors included metabolic syndrome, hypertension, and type 2 diabetes mellitus, but their prevalence varied based on the comparison group involving lean patients. Regarding non-invasive tools, Fibrosis-4 index outperformed the NAFLD fibrosis score in lean patients. Lifestyle modifications aided in reducing hepatic steatosis and improving cardiometabolic profiles, with some medications showing efficacy to a lesser extent. However, lean NAFLD patients exhibited a worse prognosis compared to the obese or overweight counterpart.

CONCLUSION

MASLD is a complex disease comprising epigenetic, genetic, and metabolic factors in its pathogenesis. Results vary across populations, gender, and age. Limited data exists on clinical practice guidelines for lean patients. Future studies employing this new nomenclature can contribute to standardizing and generalizing results among lean patients with steatotic liver disease.