Comparison of clinical and metabolic profiles of lean versus non-lean nonalcoholic fatty liver disease

Meta-Analysis: Global Prevalence and Mortality of Cirrhosis in Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is responsible for a significant global health burden. Despite this burden, the prevalence and mortality of MASLD-related cirrhosis remain inadequately defined, hindering effective public health strategies. This study aimed to estimate the global prevalence and mortality associated with MASLD-related cirrhosis.

METHODS

A systematic search of PubMed, Ovid MEDLINE, EMBASE, Web of Science and SCOPUS was conducted using keywords related to MASLD and cirrhosis from inception of each database used through June 2024. COVIDENCE was used for abstract and manuscript review. MASLD populations were categorised into 'general practice setting' and 'high risk setting', which indicated studies from inpatient setting or those referred for liver biopsy for an indication (elevated liver enzymes). Our data extraction and quality assessment followed PRISMA guidelines. A random-effects model was utilised for meta-analysis.

RESULTS

From 7924 identified articles, 35 studies comprising 513,742 patients with MASLD met the inclusion criteria. The pooled global prevalence of cirrhosis among MASLD patients was 3.26% (95% CI: 2.47%-4.31%) in general practice settings (4 studies) and 14.51% (95% CI: 11.22%-18.57%) among those in inpatient settings or referred for liver biopsy (31 studies). Regionally, higher prevalence rates in high-risk settings were observed in North America and Australia (18.38%; 95% CI: 9.06%-33.75%), followed by Europe (10.16%; 95% CI: 5.71%-17.44%) and Asia (9.12%; 95% CI: 6.11%-13.40%) (p = 0.007). Notably, ICD-based diagnoses indicated a significantly higher prevalence of cirrhosis (27.43%) compared to those diagnosed by liver biopsy (13.24%; p < 0.001). The pooled all-cause mortality rate for MASLD-cirrhosis patients was estimated at 7.91 per 100 person-years (95% CI: 4.44-13.71) (9 studies).

CONCLUSIONS

This meta-analysis underscores the substantial prevalence of cirrhosis among MASLD patients and highlights significant geographic and demographic variability, calling for improved screening and management strategies.

Integrative multiomic analysis identifies distinct molecular subtypes of NAFLD in a Chinese population

Nonalcoholic fatty liver disease (NAFLD) has become a common health care burden worldwide. The high heterogeneity of NAFLD remains elusive and impairs outcomes of clinical diagnosis and pharmacotherapy. Several NAFLD classifications have been proposed on the basis of clinical, genetic, alcoholic, or serum metabolic analyses. Yet, accurately predicting the progression of NAFLD to cirrhosis or hepatocellular carcinoma (HCC) in patients remains a challenge. Here, on the basis of a Chinese cohort of patients, we classified NAFLD into three distinct molecular subtypes (NAFLD-mSI, NAFLD-mSII, and NAFLD-mSIII) using integrative multiomics including whole-genome sequencing (WGS), proteomics, phosphoproteomics, lipidomics, and metabolomics across a broad range of liver, blood, and urine specimens. We found that NAFLD-mSI had higher expression of CYP1A2 and CYP3A4, which alleviate hepatic steatosis through mediating free fatty acid/bile acid-mTOR-FXR/PPARα signaling. NAFLD-mSII displayed an elevated risk of liver cirrhosis along with increased hepatic infiltration of M1 and M2 macrophages because of lipid-triggered hepatic CCL2 and CRP production. NAFLD-mSIII exhibited a potential risk for HCC development by increased transcription of CEBPB- and ERCC3-regulated oncogenes because of activation of the EGF-EGFR/CHKA/PI3K-PDK1-AKT cascade. Next, we validated the existence of these three NAFLD molecular subtypes in an external cohort comprising 92 patients with NAFLD across three different Chinese hospitals. These findings may aid in understanding the molecular features underlying NAFLD heterogeneity, thereby facilitating clinical diagnosis and treatment strategies with the aim of preventing the development of liver cirrhosis and HCC.

Diagnosis and Management of Lean Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): A Systematic Review

Lean metabolic dysfunction-associated steatotic liver disease (MASLD) defies traditional views of fatty liver diseases by manifesting in nonobese individuals. The renaming from nonalcoholic fatty liver disease to MASLD underscores a broader understanding of its pathophysiology, highlighting the complex interplay of metabolic factors beyond obesity. Despite its clinical importance, diagnosing and managing lean MASLD remains challenging due to its historical ties to obesity and a general lack of awareness about its unique characteristics. On December 4, 2023, a systematic literature search was conducted across six databases, focusing on peer-reviewed studies in English related to the diagnosis and management of lean MASLD. This study was registered with the International Prospective Register of Systematic Reviews (CRD42023489308). Out of 95 studies following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 43 addressed diagnosis and surveillance, whereas 52 explored management strategies. The results revealed the difficulties in diagnosing lean MASLD, pointing out the limitations of traditional markers and the potential of advanced imaging techniques. Management strategies discussed included lifestyle changes and possible pharmacological treatments tailored to the specific metabolic features of this patient group. The study highlights the necessity for increased clinical awareness, regular monitoring, and personalized therapeutic approaches for lean MASLD. It calls for further research to refine diagnostic criteria and develop targeted treatments, aiming to enhance care for individuals with lean MASLD.

Analyzing and evaluating the prevalence and metabolic profile of lean NAFLD compared to obese NAFLD: a systemic review and meta-analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is a common liver condition affecting 25%-40% of the worldwide population. NAFLD is traditionally related to obesity and metabolic disorders. NAFLD can also affect non-obese individuals, termed "lean NAFLD" (LN), who exhibit a paradoxical combination of physical leanness and metabolic obesity. Factors contributing to LN remain unclear, necessitating further research. This analysis aims to understand LN's prevalence and metabolic characteristics compared to obese NAFLD (ON) populations.

Methods

This meta-analysis searched various databases until August 1, 2023. Inclusion criteria involved observational studies comparing LN with overweight/obese NAFLD. Data extraction included baseline characteristics, disease occurrence, metabolic profile, and clinical parameters-statistical analysis employed calculating risk ratios (RR) and standard mean differences.

Results

Twenty-five studies were analyzed. LN is associated with lower prevalence in both NAFLD (RR 0.27, 95% confidence interval (CI) 0.14-0.52, p = <0.0001) and total (RR 0.27, 95% CI 0.15-0.51, p < 0.0001) population. LN had lower diabetes mellitus (RR 0.78, 95% CI 0.71-0.87, p < 0.00001), dyslipidemia (RR 0.87, 95% CI 0.79-0.95, p = 0.002), hypertension (RR 0.80, 95% CI 0.74-0.87, p < 0.00001), and metabolic syndrome (RR 0.45, 95% CI 0.31-0.64, p < 0.00001) compared to those with ON. The LN group's lipid profile, blood pressure, and other clinical parameters were favorable compared to ON.

Conclusion

The prevalence of NAFLD among lean and non-lean individuals varies by region. Our analysis revealed that LN is associated with lower metabolic diseases, fasting blood sugar, blood pressure, and a more favorable lipid profile compared to ON.

Liver diseases: Perspective from the Philippines

Liver diseases are a major cause of morbidity and mortality globally. In the Philippines, a lower middle-income country in Southeast Asia, liver diseases accounted for 27.3 cases per 1000 deaths. In this review, we discussed the prevalence, risk factors, and management of hepatitis B, hepatitis C and other viral hepatitis, non-alcoholic fatty liver disease, alcohol-associated liver disease, liver cirrhosis, and hepatocellular carcinoma. The true burden of liver disease in the Philippines is likely underestimated due to limited epidemiological studies. Thus, surveillance of liver disease should be strengthened. Clinical practice guidelines tailored to the local needs of the country have been developed for important liver diseases. Multisectoral cooperation among different stakeholders is needed to manage the burden of liver disease in the Philippines.

Comparative Burden of Metabolic Dysfunction in Lean NAFLD vs Non-lean NAFLD - A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is traditionally associated with obesity. However, there is a subtype of NAFLD, namely NAFLD in lean, that occurs without obesity. However, a recent call to redefine NAFLD to metabolic-associated fatty liver disease focuses on obesity and metabolic dysfunction. Criticism has arisen from the perceived over emphasis on systemic comorbidities, which may disadvantage the lean. The current analysis seeks to quantify the degree of metabolic dysfunction in NAFLD in lean and compare with NAFLD in overweight and obese and non-NAFLD.

METHODS

Medline and Embase databases were searched from inception to March 3, 2022. The inclusion criteria were articles with NAFLD in lean patients presenting with baseline metabolic parameters. Comparisons were conducted with subgroup analysis.

RESULTS

Eighty-five articles were included in the meta-analysis. NAFLD in lean accounted for 13.11% (95% confidence interval [CI], 10.26%-16.62%) of the global population and 14.55% (95% CI, 11.32%-18.51%) in Asia. The degree of metabolic dysfunction was weight dependent with significantly less metabolic dysfunction in NAFLD in lean subjects as compared with NAFLD in overweight counterparts. For NAFLD in lean, only 19.56% (95% CI, 15.28%-24.69%) of the subjects were diabetic, whereas 45.70% (95% CI, 35.01%-56.80%) of obese subjects with NAFLD had diabetes (P < .01). Fasting blood glucose and systolic and diastolic blood pressure values were significantly lower in subjects with NAFLD in lean than in overweight and obese.

CONCLUSION

The current analysis highlights the weight-dependent nature of metabolic dysfunction in NAFLD. Lean subjects with NAFLD were significantly less metabolically unhealthy than were obese and overweight persons with NAFLD. An overreliance on metabolic dysfunction in defining fatty liver will be a flaw in potentially excluding previously characterized NAFLD.

Mid-upper arm circumference is associated with liver steatosis and fibrosis in patients with metabolic-associated fatty liver disease: A population based observational study

Metabolic-associated fatty liver disease (MAFLD) is a series of liver diseases based on liver steatosis and metabolic disorders. Steatosis, as the core factor in MAFLD diagnosis, and fibrosis, as the major determinant of adverse outcomes of MAFLD, need to be assessed simply and accurately. In this study, we explored the significance of mid-upper arm circumference (MUAC) in evaluating liver steatosis and fibrosis in patients with MAFLD. We included 2397 cases with MAFLD from the 2017-2018 National Health and Nutrition Examination Surveys (NHANES) database. Liver steatosis and fibrosis were measured by vibration controlled transient elastography. Anthropometric parameters and demographic and serological data were obtained from the NHANES database. The association between MUAC and liver steatosis and fibrosis were evaluated by a multivariable linear regression model, a weighted generalized additive model, and smooth curve fitting using R. MUAC was positively associated with liver steatosis in every multivariate linear regression model (model 1: β = 3.3513; 95% confidence interval [CI], 2.7722-3.9304; model 2: β = 3.8492; 95% CI, 3.2441-4.4542; model 3: β = 2.4987; 95% CI, 1.8371-3.1604), and this positive association was consistent in both men and women and among different race groups (Mexican American, other Hispanic, non-Hispanic White, Black, Asian, and other race). On the other hand, MUAC was positively associated with liver fibrosis in every multivariate linear regression model, and this positive association also was consistent in both men and women and among non-Hispanic White and Black populations. Increased MUAC was positively associated with liver steatosis and fibrosis in patients with MAFLD. This was particularly true for MUAC ≥ 42.0 cm. MUAC might be a simple and convenient evaluation tool for MAFLD.

Clinical and Laboratory Characteristics of Normal Weight and Obese Individuals with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has had, over the past few decades, a progressively growing prevalence among the general population all over the world, in parallel with metabolic conditions such as type 2 diabetes mellitus (T2DM), dyslipidemia, and obesity. However, NAFLD is also detected in 10−13% of subjects with a body mass index (BMI) ≤ 25 kg/m² (lean-NAFLD), whose major risk factors remain unknown. In this study, we aimed to characterize the clinical features and associated risk factors of lean-NAFLD in comparison with obese-NAFLD patients. Consecutive patients diagnosed with NAFLD by vibration-controlled transient elastography and controlled attenuation parameter were prospectively enrolled. Biological and clinical data obtained from the participants were stratified according to their BMI in two groups: lean-NAFLD and obese-NAFLD. In total, 331 patients (56.8% males) were included in the final analysis. Most of the subjects were obese-NAFLD (n = 258, 77.9%) and had a higher prevalence of T2DM, dyslipidemia, and components of the metabolic syndrome, together with abnormal biological parameters. Regarding liver stiffness measurements, the proportion of subjects with at least significant fibrosis (≥F2) was approximately twofold higher among obese-NAFLD (43.81%) in comparison with lean-NAFLD patients (23.29%). Moreover, obese individuals had a higher risk for liver fibrosis (OR = 2.6, 95%, CI 1.5−4.42, p < 0.001) than lean individuals. Although associated metabolic conditions and at least significant liver fibrosis were present in approximately one-quarter of the patients, these were more frequent among obese-NAFLD patients. Therefore, individualized screening strategies for NAFLD should be established according to BMI.