Special Population: Lean Nonalcoholic Fatty Liver Disease

Steatotic liver disease among lean and non-lean individuals in Southern Lao PDR: a cross-sectional study of risk factors

BACKGROUND

Steatotic liver disease (SLD) prevalence is rising worldwide, linked to insulin resistance and obesity. SLD prevalence can surpass 10% even among those with normal weight. In Lao People's Democratic Republic (Lao PDR), where Opisthorchis viverrini (OV) trematode infection and type 2 diabetes mellitus (T2DM) are common, infection related liver morbidity such as cholangiocarcinoma (CCA) is high, but data on SLD prevalence is lacking. The objective of this study was to estimate the prevalence and explore determinants of SLD in rural southern Lao PDR for lean and non-lean populations.

METHOD

A cross-sectional community-based study assessed SLD prevalence using abdominal ultrasonography (US). Factors investigated for association with SLD were identified by interview, serological tests (Hepatitis B surface antigen (HBsAg); lipids and HbA1c), anthropometrical measurements, and parasitological assessments (OV infection). Uni- and multivariable logistic regression analyses with SLD as endpoint were conducted separately for lean (body mass index (BMI) <23.0 kg/m2) and non-lean (BMI ≥ 23.0 kg/m2) participants.

RESULT

2,826 participants were included. SLD prevalence was 27.1% (95% confidence interval (95% CI) 24.0%-30.4%), higher among non-lean (39.8%) than lean individuals (17.4%). Lean individuals with OV infection had a statistically significant association with lower odds of SLD (adjusted odds ratio (aOR) 0.49, 95% CI 0.33 - 0.73). T2DM showed a significant positive association with SLD in both lean (aOR 3.58, 95% CI 2.28 - 5.63) and non-lean individuals (aOR 3.31, 95% CI 2.31 - 4.74) while dyslipidemia was significantly associated only in the non-lean group (aOR 1.83, 95% CI 1.09 - 3.07). Females participants exhibited elevated odds of SLD in both lean (aOR 1.43, 95% CI 1.02 - 2.01) and non-lean SLD (aOR 1.50, 95% CI 1.12 - 2.01).

CONCLUSION

SLD prevalence is notably high among Laotian adults in rural areas, particularly in females and in non-lean individuals. Lean individuals with OV infection exhibited lower SLD prevalence. SLD was more prevalent in individuals with T2DM, independent of BMI. SLD adds to the burden of infection-related liver morbidity in Lao PDR.

Metabolic dysfunction associated fatty liver disease in healthy weight individuals

Metabolic dysfunction associated fatty liver disease (MAFLD) is an increasing public health problem, affecting one third of the global population. Contrary to conventional wisdom, MAFLD is not exclusive to obese or overweight individuals. Epidemiological studies have revealed a remarkable prevalence among healthy weight individuals, leading investigations into the genetic, lifestyle, and dietary factors that contribute to the development of MAFLD in this population. This shift in perspective requires reconsideration of preventive strategies, diagnostic criteria and therapeutic approaches tailored to address the unique characteristics of MAFLD healthy weight individuals. It also underscores the importance of widespread awareness and education, within the medical community and among the general population, to promote a more inclusive understanding of liver metabolic disorders. With this review, we aim to provide a comprehensive exploration of MAFLD in healthy weight individuals, encompassing epidemiological, pathophysiological, and clinical aspects.

Global perspective on nonalcoholic fatty liver disease and nonalcoholic steatohepatitis - prevalence, clinical impact, economic implications and management strategies

BACKGROUND

The metabolically-based liver disease, nonalcoholic fatty liver disease (NAFLD), is the most common cause of chronic liver disease currently affecting 38% of the world's adult population. NAFLD can be progressive leading to nonalcoholic steatohepatitis (NASH), liver transplantation, liver cancer, liver-related mortality and is associated with decreased quality of life from impaired physical functioning and increased healthcare resource utilisation. However, screening for NAFLD is cost-prohibitive but screening for high risk NAFLD (NAFLD with F2 fibrosis or greater) is imperative.

AIM

To review the global perspective on NAFLD and NASH METHODS: We retrieved articles from PubMed using search terms NAFLD, prevalence, clinical burden, economic burden and management strategies.

RESULTS

NAFLD/NASH shows geographical variation across the globe. Highest prevalence rates are in South America and the Middle East and North Africa; lowest prevalence is in Africa. NAFLD's economic impact is from direct and indirect medical costs and loss in worker productivity. It is projected that, over the next two decades, the total cost of NAFLD and diabetes will exceed $1.5 trillion (USD). Risk stratification algorithms identifying "high risk NAFLD" were made following non-invasive tests for NAFLD identification and fibrosis development. These algorithms should be used in primary care and endocrinology settings so timely and appropriate interventions (lifestyle and cardiometabolic risk factor management) can be initiated.

CONCLUSIONS

To reduce the burgeoning burden of NAFLD/NASH, management should include risk stratification algorithms for accurate identification of patients, linkage to appropriate settings, and initiation of effective treatment regimens.

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

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

What Is New in Metabolic Dysfunction-Associated Steatotic Liver Disease in Lean Individuals: From Bench to Bedside

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects more than 30% of the world's adult population. While it is associated with obesity and metabolic syndrome, emerging evidence has shown that a substantial number of MASLD patients have a normal body mass index ("lean individuals with MASLD"). In this article, we provide an overview of the definition, epidemiology, pathogenesis, and clinical outcomes associated with lean individuals with MASLD and updates on current management.

Mass spectrometry-based untargeted metabolomics study of non-obese individuals with non-alcoholic fatty liver disease

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is a disease characterized by the accumulation of excessive fat in the liver, which can lead to fibrosis and has an increasing prevalence. NAFLD requires non-invasive diagnostic biomarkers. While typically observed in overweight individuals, it can also occur in non-obese/non-overweight individuals. Comparative studies on non-obese NAFLD patients are scarce. This study aimed to conduct a using liquid chromatography-high resolution mass spectrometry (LC-MS/MS)-based metabolic profiling of non-obese NAFLD patients and healthy controls.

MATERIALS AND METHODS

The patient group consisted of 27 individuals with NAFLD, while the healthy control group included 39 individuals. Both groups were between 18 and 40 years old, had a BMI of less than 25 and had alcohol consumption less than 20 g/week for men and 10 g/week for women. Serum samples were collected and analyzed using LC-MS/MS. The data were analyzed using the TidyMass and MetaboAnalyst.

RESULTS

The LC-MS/MS analyses detected significant changes in D-amino acid metabolism, vitamin B6 metabolism, apoptosis, mTOR signaling pathway, lysine degradation, and phenylalanine metabolism pathways in non-obese NAFLD patients. Significant changes were also observed in the metabolites D-pantothenic acid, hypoxanthine, citric acid, citramalic acid, L-phenylalanine, glutamine, and histamine-trifluoromethyl-toluidide, β-hydroxymyristic acid, DL-Lactic acid, and 3-methyl-2-oxopentanoic. Overall, the study provides valuable insights into the metabolic changes associated with non-obese NAFLD patients and can contribute to the development of non-invasive diagnostic biomarkers for NAFLD.

CONCLUSIONS

This study sheds light on the metabolic changes in non-obese NAFLD patients. Further research is needed to better understand the metabolic changes associated with NAFLD and to develop effective treatment options.