Nonalcoholic fatty liver disease prevalence and severity in Asian Americans from the national health and nutrition examination surveys 2017–2018

Cardiovascular morbidity and mortality in lean vs. non-lean MASLD: A comprehensive meta-analysis

BACKGROUND

Lean metabolic dysfunction-associated steatotic liver disease (MASLD), characterized by a BMI < 25 kg/m² (or < 23 kg/m² in Asians), presents a challenging prognosis compared to non-lean MASLD. This study examines cardiovascular outcomes in both lean and non-lean MASLD cohorts.

METHODS

In this meta-analysis, pooled odds ratios (ORs) within 95 % confidence intervals (CIs) were calculated for primary outcomes (cardiovascular mortality and major adverse cardiovascular events [MACE]) and secondary outcomes (cardiovascular disease [CVD], all-cause mortality, hypertension, and dyslipidemia). Studies comparing lean and non-lean MASLD within the same cohorts were analyzed, prioritizing those with larger sample sizes or recent publication dates.

RESULTS

Twenty-one studies were identified, encompassing lean MASLD patients (n = 7153; mean age 52.9 ± 7.4; 56 % male) and non-lean MASLD patients (n = 23,514; mean age 53.2 ± 6.8; 63 % male). Lean MASLD exhibited a 50 % increase in cardiovascular mortality odds compared to non-lean MASLD (OR: 1.5, 95 % CI 1.2-1.8; p < 0.0001). MACE odds were 10 % lower in lean MASLD (OR: 0.9, 95 % CI 0.7-1.2; p = 0.7), while CVD odds were 40 % lower (p = 0.01). All-cause mortality showed a 40 % higher odds in lean MASLD versus non-lean MASLD (p = 0.06). Lean MASLD had 30 % lower odds for both hypertension (p = 0.01) and dyslipidemia (p = 0.02) compared to non-lean MASLD.

CONCLUSION

Despite a favorable cardiometabolic profile and comparable MACE rates, lean individuals with MASLD face elevated cardiovascular mortality risk.

Global epidemiology of type 2 diabetes in patients with NAFLD or MAFLD: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) shares common pathophysiological mechanisms with type 2 diabetes, making them significant risk factors for type 2 diabetes. The present study aimed to assess the epidemiological feature of type 2 diabetes in patients with NAFLD or MAFLD at global levels.

METHODS

Published studies were searched for terms that included type 2 diabetes, and NAFLD or MAFLD using PubMed, EMBASE, MEDLINE, and Web of Science databases from their inception to December 2022. The pooled global and regional prevalence and incidence density of type 2 diabetes in patients with NAFLD or MAFLD were evaluated using random-effects meta-analysis. Potential sources of heterogeneity were investigated using stratified meta-analysis and meta-regression.

RESULTS

A total of 395 studies (6,878,568 participants with NAFLD; 1,172,637 participants with MAFLD) from 40 countries or areas were included in the meta-analysis. The pooled prevalence of type 2 diabetes among NAFLD or MAFLD patients was 28.3% (95% confidence interval 25.2-31.6%) and 26.2% (23.9-28.6%) globally. The incidence density of type 2 diabetes in NAFLD or MAFLD patients was 24.6 per 1000-person year (20.7 to 29.2) and 26.9 per 1000-person year (7.3 to 44.4), respectively.

CONCLUSIONS

The present study describes the global prevalence and incidence of type 2 diabetes in patients with NAFLD or MAFLD. The study findings serve as a valuable resource to assess the global clinical and economic impact of type 2 diabetes in patients with NAFLD or MAFLD.

Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race

OBJECTIVE

The objective of this study was to assess the performance of noninvasive tests (NITs) across different racial and ethnic groups in a large multiethnic cohort.

METHODS

Data were derived from the National Health and Nutrition Examination Survey (NHANES) 2017 through 2020. Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study.

RESULTS

Among the 6359 adults included in the study, fatty liver index and nonalcoholic fatty liver disease liver fat scores performed well for the prediction of metabolic dysfunction-associated steatotic liver disease, without significant changes across racial and ethnic groups. However, significant differences were observed across racial and ethnic groups for the prediction of advanced fibrosis and cirrhosis. The fibrosis-4 (FIB-4) index, aspartate aminotransferase to platelet ratio index (APRI), and nonalcoholic fatty liver disease fibrosis score underperformed in non-Hispanic Black patients for the detection of cirrhosis. For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI. Using a cutoff point of 12 kPa for advanced fibrosis, both APRI and the FIB-4 index performed significantly worse in non-Hispanic Black patients.

CONCLUSIONS

In a large, diverse national cohort, the performance of NITs was overall poor compared with transient elastography, and NITs showed differences across racial and ethnic groups. Given the widespread use of NITs, it is imperative that the scores are equitable across racial and ethnic groups.

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.

Prevalence Study of MASLD in Adolescent and Young Adult Pacific Islanders and Asians Living in Hawai'i

Context

Nonalcoholic fatty liver disease, renamed metabolic dysfunction-associated steatotic liver disease (MASLD), is the most common cause of chronic liver disease with an estimated worldwide prevalence of 30.1% while clinical practice observations reflect a disproportionately lower prevalence of 1.9%, indicating a condition that is underrecognized in clinical care settings. Screening for MASLD is rarely performed, and little is known about the prevalence in Hawai'i.

Objective

This pilot aims to develop an understanding of the prevalence and factors associated with MASLD in Hawai'i's adolescent and young adult (AYA) population.

Design/Methods

Cross-sectional observational pilot study: We used Fibroscan®-liver ultrasonographic vibration-controlled transient elastography (VCTE) to identify MASLD based on controlled attenuation parameter (CAP) scores ≥238 (dB/m) and collected biometric, anthropometric, and Beverage Intake Questionnaire (sugar-sweetened beverage) survey data.

Setting

The study took place at community clinics in Hawai'i on the island of O'ahu.

Participants

One hundred individuals were evaluated, age 14 to 34 years.

Main Outcome Measures

We used VCTE Fibroscan® with CAP scoring to identify the presence of hepatocyte steatosis (fatty liver).

Results

Overall MASLD prevalence in the sample was 44% (95% confidence interval: 34.1%-54.3%). In participants with MASLD, obese Native Hawaiian and other Pacific Islanders (62%) and nonobese Asians (43%) had the highest rates of MASLD.

Conclusion

This pilot evaluation of the AYA NHOPI and Asian MASLD population in Hawai'i shows a higher rate of MASLD than those reported in other parts of the United States. Larger population health studies are indicated to expand our knowledge of MASLD in the Hawaiian Islands.

Non-Pharmacological Approach to Diet and Exercise in Metabolic-Associated Fatty Liver Disease: Bridging the Gap between Research and Clinical Practice

This review provides a practical and comprehensive overview of non-pharmacological interventions for metabolic-associated fatty liver disease (MASLD), focusing on dietary and exercise strategies. It highlights the effectiveness of coffee consumption, intermittent fasting, and Mediterranean and ketogenic diets in improving metabolic and liver health. The review emphasizes the importance of combining aerobic and resistance training as a critical approach to reducing liver fat and increasing insulin sensitivity. Additionally, it discusses the synergy between diet and exercise in enhancing liver parameters and the role of gut microbiota in MASLD. The paper underscores the need for a holistic, individualized approach, integrating diet, exercise, gut health, and patient motivation. It also highlights the long-term benefits and minimal risks of lifestyle interventions compared to the side effects of pharmacological and surgical options. The review calls for personalized treatment strategies, continuous patient education, and further research to optimize therapeutic outcomes in MASLD management.

Impact of smoking cessation on non-alcoholic fatty liver disease prevalence: a systematic review and meta-analysis

OBJECTIVES

The negative effects of smoking on numerous cardiovascular and metabolic diseases have been widely acknowledged. However, the potential effect of smoking cessation is relatively unelucidated. The objective of this study is to explore whether the prevalence of non-alcoholic fatty liver disease (NAFLD) in former smokers differs from the prevalence in current smokers.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Four databases, that is, PubMed, Web of Science, Journal@Ovid and Scopus were searched from inception to 31 January 2023.

ELIGIBILITY CRITERIA

Population-based cross-sectional studies, including the baseline data of cohort studies with identified NAFLD diagnostic methods, and smoking status (current smoker or former smoker) of participants were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted the data including cigarette smoking status, country/region of studies, NAFLD diagnostic methods, sex, the average age and body mass index (BMI) of NAFLD participants and assessed the risk of bias with Agency for Healthcare Research and Quality (AHRQ) methodology checklist. Risk ratio (RR) of NAFLD prevalence in former smokers was pooled using the random-effects model.

RESULTS

28 studies involving 4 465 862 participants were included. Compared with current smokers, the RR of overall NAFLD prevalence in former smokers was 1.13 (95% CI: 1.08 to 1.19, prediction interval: 0.92-1.39). This result persisted after adjustment for diagnostic methods, country/region, sex, age and BMI. Sensitivity analysis and risk of bias assessment indicated a stable conclusion.

CONCLUSIONS

NAFLD prevalence in former smokers was at least not lower than that in current smokers and was partially related to increased BMI after smoking cessation, indicating that smoking cessation was possibly not a protective factor against NAFLD. Although the meta-analysis based on cross-sectional studies cannot conclude the causal relationships between smoking cessation and NAFLD onset, the potential onset of NAFLD associated with smoking cessation should be highlighted.

PROSPERO REGISTRATION NUMBER

CRD42023394944.

Ethnic disparities in waitlist outcomes of patients with nonalcoholic steatohepatitis listed for liver transplantation in the US

NASH is the fastest-growing cause of liver cirrhosis and is the leading indication for liver transplantation (LT). However, significant racial and ethnic disparities in waitlist outcomes and LT allocation may unfairly disadvantage minorities. Our aim was to characterize racial and ethnic disparities in waitlist mortality and transplantation probability among patients with NASH. This is a retrospective analysis of the United Network for Organ Sharing registry data of LT candidates from January 1, 2000 to December 31, 2021. Outcomes analysis was performed using competing risk analysis with the Fine and Gray model. The multivariable adjustment was conducted, and mixed-effect regression was used to compare the model for end-stage liver disease scores at listing and removal. Of 18,562 patients with NASH cirrhosis, there were 14,834 non-Hispanic Whites, 349 African Americans, 2798 Hispanics, 312 Asians, and 269 of other races/ethnicities; African American (effect size: 2.307, 95% CI: 1.561-3.053, and p < 0.001) and Hispanic (effect size: 0.332, 95% CI: 0.028-0.637, p = 0.032) patients were found to have a significantly higher model for end-stage liver disease scores at the time of listing than non-Hispanic Whites. African Americans had a higher probability of receiving LT relative to non-Hispanic Whites (subdistribution HR: 1.211, 95% CI: 1.051-1.396, and p = 0.008). However, Hispanic race/ethnicity was associated with a lower transplantation probability (subdistribution HR: 0.793, 95% CI: 0.747-0.842, and p < 0.001) and increased waitlist mortality (subdistribution HR: 1.173, CI: 1.052-1.308, and p = 0.004) compared with non-Hispanic Whites. There are significant racial and ethnic disparities in waitlist outcomes of patients with NASH in the US. Hispanic patients are less likely to receive LT and more likely to die while on the waitlist compared with non-Hispanic Whites despite being listed with a lower model for end-stage liver disease scores.

Looking Across and Within: Immigration as a Unifying Structural Factor Impacting Cardiometabolic Health and Diet

Introduction

Immigration has been identified as an important social determinant of health (SDH), embodying structures and policies that reinforce positions of poverty, stress, and limited social and economic mobility. In the public health literature with regard to diet, immigration is often characterized as an individual-level process (dietary acculturation) and is largely examined in one racial/ethnic subgroup at a time. For this narrative review, we aim to broaden the research discussion by describing SDH common to the immigrant experience and that may serve as barriers to healthy diets.

Methods

A narrative review of peer-reviewed quantitative, qualitative, and mixed methods studies on cardiometabolic health disparities, diet, and immigration was conducted.

Results

Cardiometabolic disease disparities were frequently described by racial/ethnic subgroups instead of country of origin. While cardiovascular disease and obesity risk differed by country of origin, diabetes prevalence was typically higher for immigrant groups vs United States (US)-born individuals. Common barriers to achieving a healthy diet were food insecurity; lack of familiarity with US food procurement practices, food preparation methods, and dietary guidelines; lack of familiarity and distrust of US food processing and storage methods; alternative priorities for food purchasing (eg, freshness, cultural relevance); logistical obstacles (eg, transportation); stress; and ethnic identity maintenance.

Conclusions

To improve the health of immigrant populations, understanding similarities in cardiometabolic health disparities, diet, and barriers to health across immigrant communities-traversing racial/ethnic subgroups-may serve as a useful framework. This framework can guide research, policy, and public health practices to be more cohesive, generalizable, and meaningfully inclusive.

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.

Type 2 diabetes mellitus in metabolic-associated fatty liver disease vs. type 2 diabetes mellitus non-alcoholic fatty liver disease: a longitudinal cohort analysis

INTRODUCTION AND OBJECTIVES

Type 2 Diabetes Mellitus (T2DM) is comorbidity commonly presenting with fatty liver. A recently proposed definition of "metabolic associated fatty liver disease" (MAFLD) is thought to replace non-alcoholic fatty liver disease (NAFLD). Yet, despite the significant prevalence of T2DM among fatty liver, there remains limited evidence on the impact of the change in the definition of T2DM.

MATERIALS AND METHODS

The current study uses data from the United States National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. Survival analysis was conducted with a cox regression and sub-distribution hazard ratio for competing risk events.

RESULTS

6727 patients had a diagnosis of T2DM. 4982 individuals with T2DM had MAFLD and 2032 were MAFLD(+)/NAFLD(-), while 2950 patients were MAFLD(+)/NAFLD(+). The new definition increased fatty liver diagnosis by 68.89%. Patients who were classified as MAFLD(+)/NAFLD(-) were at a higher risk of major adverse cardiovascular events, advanced fibrosis, all-cause and cardiovascular-related mortality compared to MAFLD(+)/NAFLD(+). In MAFLD(+)/NAFLD(-), viral hepatitis significantly increases the odds of advanced fibrosis (OR: 6.77, CI: 3.92 to 11.7, p < 0.001) and all-cause mortality (HR: 1.75, CI: 1.29 to 2.40, p < 0.001).

CONCLUSIONS

The identification and treatment of NAFLD in patients with T2DM is a major concern and the premature change to MAFLD results in an over-diagnosis of fatty liver, exaggerated mortality, and morbidity in patients with T2DM. The definition of MAFLD causes further heterogeneity in fatty liver disease/NAFLD.

Examining the interim proposal for name change to steatotic liver disease in the US population

BACKGROUND AND AIMS

Fatty liver is the commonest liver condition globally and traditionally associated with NAFLD. A consensus meeting was held in Chicago to explore various terminologies. Herein, we explore the proposed changes in nomenclature in a population data set from the US.

APPROACH AND RESULTS

Statistical analysis was conducted using survey-weighted analysis. Assessment of fatty liver was conducted with vibration-controlled transient elastography. A controlled attenuation parameter of 288 dB/m was used to identify hepatic steatosis. Patients were classified into nonalcoholic steatotic liver disease, alcohol-associated steatotic liver disease, and viral hepatitis steatotic liver disease. Liver stiffness measures at ≥8.8, ≥11.7, and ≥14 kPa were used to identify clinically significant fibrosis, advanced fibrosis, and cirrhosis, respectively. A total of 5102 individuals were included in the analysis. Using a survey-weighted analysis, a total of 25.43%, 6.95%, and 0.73% of the population were classified as nonalcoholic steatotic liver disease, alcohol-associated steatotic liver disease, and viral hepatitis steatotic liver disease, respectively. A sensitivity analysis at controlled attenuation parameter of 248 dB/m and fatty liver index found similar distribution. In a comparison between nonalcoholic steatotic liver disease, alcohol-associated steatotic liver disease, and viral hepatitis steatotic liver disease, there was no significant difference between the odds of advanced fibrosis and cirrhosis between groups. However, viral hepatitis steatotic liver disease individuals were found to have a significantly higher odds of clinically significant fibrosis (OR: 3.76, 95% CI, 1.27-11.14, p =0.02) compared with nonalcoholic steatotic liver disease.

CONCLUSIONS

The current analysis assessed the proposed changes based on discussions from the consensus meeting. Although the definitions are an interim analysis of discussions, steatotic liver disease respects the underlying liver etiology and reduces stigma while increasing awareness of FL among viral and alcohol-associated steatosis/steatohepatitis.

Prepandemic Prevalence Estimates of Fatty Liver Disease and Fibrosis Defined by Liver Elastography in the United States

BACKGROUND AND AIMS

Fatty liver disease is a growing public health burden. We estimated prepandemic fatty liver disease prevalence determined by transient elastography-assessed hepatic steatosis and fibrosis, and examined associations with lifestyle and other factors in a United States population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 7923 non-Hispanic white, non-Hispanic black, non-Hispanic Asian, and Hispanic men and women aged 20 years and over in the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020 prepandemic data.

RESULTS

The prevalence of fatty liver disease (CAP > 300 dB/m) was 28.8% and of fibrosis (liver stiffness > 8 kPa) was 10.4%. Only 7.2% of participants with fatty liver disease and 10.9% with fibrosis reported being told by a health care provider that they had liver disease. In addition to known risk factors such as metabolic factors and ALT, persons with fatty liver disease were less likely to meet physical activity guidelines, more likely to be sedentary for ≥ 12 h a day, and reported a less healthy diet. Persons with fibrosis were less likely to have a college degree and reported a less healthy diet.

CONCLUSIONS

In the U.S. population, most persons with fatty liver disease are unaware of their condition. Physical activity and dietary modifications might reduce the fatty liver disease burden. There is an urgent need for fatty liver disease management in high-risk individuals using transient elastography or other noninvasive methods to intervene in disease progression.

New insights into the bile acid-based regulatory mechanisms and therapeutic perspectives in alcohol-related liver disease

Cholestasis is a key causative factor in alcohol-related liver disease (ALD) and variable degrees of cholestasis occur in all stages of ALD. However, the pathogenetic mechanisms and biomarkers associated with cholestasis are not well characterized. Cholestatic disease is marked by the disruption of bile acids (BA) transport and homeostasis. Consequently, in both human and experimental ALD, the disease shows a direct correlation with an imbalance in BA equilibrium, which in turn may also affect the severity of the disease. Modulation of BA metabolism or signaling pathways is increasingly considered as a potential therapeutic strategy for ALD in humans. In this paper, we highlight the key advances made in the past two decades in characterizing the molecular regulatory mechanisms of BA synthesis, enterohepatic circulation, and BA homeostasis. We summarize recent insights into the nature of the linkage between BA dysregulation and ALD, including the abnormal expression of genes involved in BA metabolism, abnormal changes in receptors that regulate BA metabolism, and disturbance in the gut flora engaged in BA metabolism caused by alcohol consumption. Additionally, we provide novel perspectives on the changes in BAs in various stages of ALD. Finally, we propose potential pharmacological therapies for ALD targeting BA metabolism and signaling.