Clinical Profiles of Asians with NAFLD: A Systematic Review and Meta-Analysis

Prevalence of at-risk MASH, MetALD and alcohol-associated steatotic liver disease in the general population

BACKGROUND

The prevalence of at-risk metabolic dysfunction-associated steatohepatitis (at-risk MASH) has not been systematically assessed.

AIM

To delineate the prevalence of at-risk MASH in a large population-based cohort.

METHODS

We conducted a cross-sectional analysis of 40,189 patients in the UK Biobank who underwent liver MRI. Hepatic steatosis was determined by proton density fat fraction (PDFF) ≥5%. Based on AASLD criteria, participants were classified as alcohol-associated steatotic liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), combined metabolic alcoholic liver disease (MetALD) and at-risk MASH.

RESULTS

Among 40,189 patients, 10,886 (27.0%) had a PDFF ≥5%, indicating SLD. Among patients with SLD, 1% had ALD, 89.0% had MASLD, 7.9% had MetALD and 2.2% had at-risk MASH. The at-risk MASH group, which included 0.6% of the general population, had the highest mean liver fat on MRI and the highest BMI. Serum biomarkers highlighted increased inflammation and metabolic changes in at-risk MASH. The prevalence of MASLD was significantly higher among men with a BMI ≥30 kg/m2. Non-obese women showed only a 12% risk of MASLD. Conversely, MetALD had similar prevalence in obese men and women and was absent in non-obese women.

CONCLUSIONS

MASLD is prevalent among patients with elevated PDFF on MRI. There are different sex- and BMI-specific prevalence of different steatotic liver disorders. At-risk MASH demonstrates the most severe metabolic and inflammatory profiles. This study provides novel estimates for the at-risk MASH population that will be eligible for treatment with pharmacologic therapy when approved by regulatory authorities.

Upper limit of normal ALT levels in health and metabolic diseases: Pooled analysis of 423,355 individuals with bootstrap modelling

INTRODUCTION

Given the global rise in obesity-related metabolic diseases, the upper limit of normal (ULN) alanine aminotransferase (ALT) in individuals with and without metabolic diseases may have changed. We performed a meta-analysis combined with bootstrap modelling to estimate the ALT ULN levels for individuals with and without metabolic diseases.

METHODS AND RESULTS

Two separate searches of the PubMed, Embase and Cochrane databases were performed, one to identify healthy individuals which yielded 12 articles (349,367 individuals); another to include those with potential metabolic diseases but without known liver disease which yielded 35 articles (232,388 individuals). We estimated the mean ALT using a random-effects mixed model and the ULN level (95th-percentile value) via a bootstrap model with 10,000 resamples. In individuals without metabolic diseases and known liver disease, the ALT ULN levels were 32 U/L overall; 36 U/L in males and 28 U/L in females. In analyses that included individuals with metabolic diseases, the ALT ULN levels were 40 U/L among the overweight/obese (29 U/L if normal weight) and 36 U/L among those with type 2 diabetes mellitus (T2DM) (33 U/L if no T2DM). On meta-regression of study-level factors, body mass index (coefficient 1.49, 95% CI 0.11-2.86, p = 0.03), high-density lipoprotein (coefficient -0.47, 95% CI -0.85-(-0.08), p = 0.02) and triglycerides (coefficient 0.19, 95% CI 0.12-0.25, p < 0.0001) correlated with ALT.

CONCLUSION

We provide expected ranges of ALT ULN levels for individuals without known liver disease without metabolic diseases and those with or without T2DM and/or are normal weight or overweight/obese. These data may have implications for clinical care and screening.

Limitations of BMI z scores for assessing weight change: A clinical tool versus individual risk

Although pediatric growth curves provide clinical utility, using these metrics for within-person change over time can be misleading. As research is focused on understanding cardiometabolic consequences of weight gain, it is important to use precise metrics to analyze these longitudinal research questions. Despite several foundational recommendations to limit the use of reference pediatric growth curves (e.g., BMI z scores) for within-person longitudinal research, it has evolved into the "gold standard" for using growth curves for pediatric weight gain analyses. Therefore, the objective of this paper is to discuss (A) the methodology used to create reference growth curves; (B) the appropriate use of reference pediatric BMI growth curves within the context of cross-sectional and longitudinal analyses in research; and (C) how to select metrics based on desired evaluations. Careful consideration using standardized references scores is essential when assessing obesity-related questions and comorbid risk over time in pediatric populations.

Hepatocellular Carcinoma: The Role of Surgery in Liver Cirrhosis

Background

Liver surgery is an essential component of hepatocellular carcinoma (HCC) treatment. Advances in surgical techniques and perioperative care have improved outcomes and have helped to expand surgical indications. However, liver fibrosis and cirrhosis still remain major problems for liver surgery due to the relevant impact on liver regeneration of the future liver remnant (FLR) after surgery. Especially in patients with clinically significant portal hypertension due to liver cirrhosis, surgery is limited. Despite recent efforts in developing predictive models, estimating the postoperative hepatic function remains difficult.

Summary

In this review, we focus on the role of surgery in the treatment of HCC in structurally altered livers. The importance of assessing FLR with techniques such as contrast-enhanced CT, e.g., with the help of artificial intelligence is highlighted. Moreover, strategies for increasing the FLR with approaches like portal vein embolization and liver vein deprivation prior to surgery are discussed. Patient selection, minimally invasive liver surgery including robotic techniques, and perioperative concepts like the Enhanced Recovery After Surgery (ERAS) guidelines are identified as crucial parts of avoiding posthepatectomy liver failure.

Key Message

The need for ongoing research to optimize patient selection criteria and perioperative care and to develop innovative biomarkers for outcome prediction is emphasized.

Metabolic puzzle: Exploring liver fibrosis differences in Asian metabolic-associated fatty liver disease subtypes

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is a liver condition marked by excessive fat buildup in the absence of heavy alcohol use. It is primarily linked with metabolic issues like insulin resistance, obesity, and abnormal lipid levels, and is often observed with other conditions such as type 2 diabetes and cardiovascular disease. However, whether the subtypes of MAFLD based on the metabolic disorder differentially impact liver fibrosis is not well explicated, especially in the Asian population.

AIM

To compare the severity of liver fibrosis among different MAFLD subtypes.

METHODS

A total of 322 adult patients of either gender with fatty liver on ultrasound were enrolled between January to December 2021. MAFLD was defined as per the Asian Pacific Association for the Study of the Liver guidelines. Fibrosis-4 index (Fib-4) and nonalcoholic fatty liver disease fibrosis score (NFS) were employed to evaluate liver fibrosis.

RESULTS

The mean age was 44.84 ± 11 years. Seventy-two percent of the patients were female. Two hundred and seventy-three patients were classified as having MAFLD, of which 110 (40.3%) carried a single, 129 (47.3%) had two, and 34 (12.5%) had all three metabolic conditions. The cumulative number of metabolic conditions was related to elevated body mass index, triglyceride (TG) levels, and glycated hemoglobin, lower high-density lipoprotein (HDL) levels, higher liver inflammation (by aspartate aminotransferase and γ-glutamyl transferase), and higher likelihood of fibrosis (by NFS and Fib-4 scores) (P < 0.05 for all). The proportion of advanced fibrosis also increased with an increase in the number of metabolic conditions (4.1%, 25.5%, 35.6%, and 44.1% by NFS and 6.1%, 10.9%, 17%, and 26.5% by Fib-4 for no MAFLD and MAFLD with 1, 2, and 3 conditions, respectively). Among MAFLD patients, those with diabetes alone were the eldest and had the highest mean value of NFS score and Fib-4 score (P < 0.05), while MAFLD patients diagnosed with lean metabolic dysfunction exhibited the highest levels of TG and alanine aminotransferase but the lowest HDL levels (P < 0.05).

CONCLUSION

The study suggests that the severity of liver fibrosis in MAFLD patients is influenced by the number and type of metabolic conditions present. Early identification and management of MAFLD, particularly in patients with multiple metabolic conditions, are crucial to prevent liver-related complications.

The burden of nonalcoholic fatty liver disease (NAFLD) is rapidly growing in every region of the world from 1990 to 2019

BACKGROUND

The latest meta-analyses suggest NAFLD is increasing globally. Its limitations may preclude accurate estimates. We evaluated the global NAFLD burden and its' trends in prevalence and NAFLD liver-related mortality (LRM) by sex, age, region, and country over the past 3 decades using data from the Global Burden of Disease (GBD) 2019 study.

METHODS

Crude and age-standardized NAFLD prevalence and NAFLD-LRM rates were obtained for all-age individuals with NAFLD from 204 countries/territories between 1990 and 2019. Joinpoint trend analysis assessed time trends. Weighted average of the annual percent change (APC) over the period 1990-2019 and 2010-2019 were reported.

RESULTS

All-age (children and adults) crude global NAFLD prevalence increased:10.5% (561 million)-16.0% (1,236 million); an APC increase: + 1.47% (95% CI, 1.44%, 1.50%). Among adults (+20 y), crude NAFLD prevalence increased (1990: 17.6%, 2019:23.4%; APC: + 1.00%, 95% CI: 0.97%, 1.02%). In all-age groups, the crude NAFLD-LRM rate (per 100,000) increased (1990: 1.75%, 2019: 2.18%; APC: + 0.77% (95% CI, 0.70%, 0.84%). By Joinpoint analysis, from 2010 to 2019, worsening all-age trends in NAFLD prevalence and LRM were observed among 202 and 167 countries, respectively. In 2019, there were 1.24 billion NAFLD prevalent cases and 168,969 associated deaths; Asia regions accounted for 57.2% of all-age prevalent cases and 46.2% of all-age NAFLD-LRM. The highest all-age crude NAFLD prevalence rate was the Middle East and North Africa (LRM 26.5%); the highest all-age crude NAFLD-LRM rate was Central Latin America (5.90 per 100,000).

CONCLUSIONS

NAFLD is increasing globally in all-age groups-over 80% of countries experienced an increase in NAFLD and NAFLD-LRM. These data have important policy implications for affected countries and for global health.

Prevalence and associated factors for non-alcoholic fatty liver disease among adults in the South Asian Region: a meta-analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease worldwide. We estimated the prevalence and predefined associated factors for NAFLD among South-Asian adults.

Methods

We searched PubMed and included descriptive, epidemiological studies with satisfactory methodology, reporting the prevalence of NAFLD with ultrasound. Two authors screened and extracted data independently. Gender, urban/rural settings, general population and individuals with metabolic diseases (MetD) stratified the analysis. In addition, a random-effects meta-analysis of the prevalence and effect sizes of associations of NAFLD was performed.

Findings

Twenty-two publications were included after the quality assurance process. The difference in the NAFLD prevalence between the general population and people with MetD was found to be statistically significant (Q = 15.8, DF = 1, P < 0.001). The pooled overall prevalence of NAFLD in the general population was 26.9% (95% CI: 18.9-35.8%) with high heterogeneity. The prevalence was similar among men and women (Q = 0.06, DF = 1, P = 0.806). The NAFLD prevalence in the rural communities was 22.6% (95% CI: 13.6-33.1%), and the prevalence in urban communities was 32.9% (95% CI: 22.8-43.8%) and the difference was not statistically significant (Q = 1.92, DF = 1, P = 0.166). The pooled overall prevalence of NAFLD in patients with MetD was 54.1% (95% CI: 44.1-63.9%) with high heterogeneity. The pooled overall prevalence of NAFLD in the non-obese population was 11.7% (95% CI: 7.0-17.3%). The pooled prevalence of non-obese NAFLD in the NAFLD population was 43.4% (95% CI: 28.1-59.4%). Meta-analysis of binary variables showed that NAFLD in the South Asian population was associated with diabetes mellitus, hypertension, dyslipidaemia, general obesity, central obesity and metabolic syndrome. Gender was not associated with NAFLD.

Interpretation

The overall prevalence of NAFLD among adults in South Asia is high, especially in those with MetD, and a considerable proportion is non-obese. In the South Asian population, NAFLD was associated with diabetes mellitus, hypertension, dyslipidaemia, general obesity, central obesity, and metabolic syndrome.

Funding

None.

Assessing the clinical utility of major indices for nonalcoholic fatty liver disease in East Asian populations

Nonalcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease. The growing prevalence of NAFLD is strongly associated with the high incidence of metabolic syndrome. NAFLD affects as much as 19% of the US population with a disproportionate impact on minority racial groups such as Asian Americans. If not promptly managed, NAFLD may progress to more feared complications. Liver indices for NAFLD screening have been proposed but were often developed using study populations with different anthropometrics than patients of East Asian descent. This review compares the accuracy of five indices for NAFLD screening in Asian cohorts. The Fatty Liver Index performed well in multiple large-scale community studies, although other indices may be more suited for specific patient cohorts. This is important, as the utilization of liver indices could accelerate screening for NAFLD for early management and to reduce liver disease-related health disparities among Asian Americans.

Correlation between nonalcoholic fatty liver disease and left ventricular diastolic dysfunction in non-obese adults: a cross-sectional study

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with a greater risk of developing cardiovascular disease and have adverse impacts on the cardiac structure and function. Little is known about the effect of non-obese NAFLD upon cardiac function. We aimed to compare the echocardiographic parameters of left ventricle (LV) between non-obese NAFLD group and control group, and explore the correlation of non-obese NAFLD with LV diastolic dysfunction.

METHODS AND RESULTS

In this cross-sectional study, 316 non-obese inpatients were enrolled, including 72 participants with NAFLD (non-obese NAFLD group) and 244 participants without NAFLD (control group). LV structural and functional indices of two groups were comparatively analyzed. LV diastolic disfunction was diagnosed and graded using the ratio of the peak velocity of the early filling (E) wave to the atrial contraction (A) wave and E value. Compared with control group, the non-obese NAFLD group had the lower E/A〔(0.80 ± 0.22) vs (0.88 ± 0.35), t = 2.528, p = 0.012〕and the smaller LV end-diastolic diameter〔(4.51 ± 0.42)cm vs (4.64 ± 0.43)cm, t = 2.182, p = 0.030〕. And the non-obese NAFLD group had a higher prevalence of E/A < 1 than control group (83.3% vs 68.9%, X² = 5.802, p = 0.016) while two groups had similar proportions of LV diastolic dysfunction (58.3% vs 53.7%, X² = 0.484, p = 0.487). Multivariate logistic regression analysis showed that non-obese NAFLD was associated with an increase in E/A < 1 (OR = 6.562, 95%CI 2.014, 21.373, p = 0.002).

CONCLUSIONS

Non-obese NAFLD was associated with decrease of E/A, while more research will be necessary to evaluate risk of non-obese NAFLD for LV diastolic dysfunction in future.