Nonalcoholic Steatohepatitis Is the Most Rapidly Increasing Indication for Liver Transplantation in the United States

Changing Trends of Cirrhotic and Noncirrhotic Hepatocellular Carcinoma in the Era of Directly-Acting Antiviral Agents

INTRODUCTION

The impact of direct-acting antivirals (DAAs) for hepatitis C virus (HCV) on burden of cirrhotic and noncirrhotic hepatocellular carcinoma (HCC) has not been examined. We assessed recent trends in liver disease etiologies of HCC and proportion of noncirrhotic HCC since DAAs introduction.

METHODS

Clinical characteristics including presence or absence of underlying cirrhosis were collected from 2,623 patients diagnosed with HCC between 2009 and 2019 at 2 large US centers. Logistic regression was performed to investigate the annual trends of HCC due to different liver diseases and proportions of noncirrhotic cases.

RESULTS

In the DAA era (2014-2019), annual decline in HCV-HCC (odds ratio [OR] = 0.93, 95% confidence interval [CI] 0.88-0.99, P = 0.019), without change in trends of other liver diseases-related HCC, was observed. Annual increase in noncirrhotic HCC (OR 1.13, 95% CI 1.03-1.23, P = 0.009) and decline in cirrhotic HCC (OR 0.89, 95% CI 0.81-0.97, P = 0.009) along with similar trends for HCV-HCC-increase in noncirrhotic cases (OR 1.35, 95% CI 1.08-1.69, P = 0.009) and decrease in cirrhotic cases (OR 0.92, 95% CI 0.86-0.98, P = 0.012)-were observed during the DAA era. Compared with the pre-DAA era, HCC resection rate increased (10.7% vs 14.0%, P = 0.013) whereas liver transplantation rate decreased (15.1% vs 12.0%, P = 0.023) in the DAA era.

DISCUSSION

Since introduction of DAAs, proportions of cirrhotic HCC have decreased, whereas proportions of noncirrhotic HCC have increased. These new trends were associated with change in utilization of liver resection and transplantation for HCC. The impact of changing patterns of DAA use on these trends will require further study.

Role of FXR in Bile Acid and Metabolic Homeostasis in NASH: Pathogenetic Concepts and Therapeutic Opportunities

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent cause of liver disease, increasingly contributing to the burden of liver transplantation. In search for effective treatments, novel strategies addressing metabolic dysregulation, inflammation, and fibrosis are continuously emerging. Disturbed bile acid (BA) homeostasis and microcholestasis via hepatocellular retention of potentially toxic BAs may be an underappreciated factor in the pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) as its progressive variant. In addition to their detergent properties, BAs act as signaling molecules regulating cellular homeostasis through interaction with BA receptors such as the Farnesoid X receptor (FXR). Apart from being a key regulator of BA metabolism and enterohepatic circulation, FXR regulates metabolic homeostasis and has immune-modulatory effects, making it an attractive therapeutic target in NAFLD/NASH. In this review, the molecular basis and therapeutic potential of targeting FXR with a specific focus on restoring BA and metabolic homeostasis in NASH is summarized.

Non-alcoholic Steatohepatitis: From Pathophysiology to Clinical Practice

Non-alcoholic steatohepatitis (NASH) is becoming a global disease with significant associated comorbidities. To date, there are no commercialized drugs to treat NASH, outside of India; however, there is an abundance of new molecular entities which are in clinical development, some in phase III trials. Many of these trials have created an especially heavy demand for USA-based subjects. Hepatologists currently play a major role in the diagnosis, treatment and clinical-trial enrolment of patients with NASH. However, NASH has a strong metabolic component, with patients often carrying comorbid diseases, such as type 2 diabetes mellitus, obesity, hyperlipidaemia, hypothyroidism and sex steroid disorders. The primary care physician, internist and endocrinologist stand at a pivotal position in the NASH healthcare delivery system, as many of the diseases they commonly encounter are associated with a higher risk of developing NASH. Specialty society practice guidelines are evolving regarding the identification and care of patients with NASH. This review of the literature, and assessment of IQVIA's proprietary patient claims database of diagnosis codes, patient encounters and treatments, substantiates the importance of the primary care provider and endocrinologist in the clinical care and clinical research of patients with NASH.

Poor Awareness of Liver Disease Among Adults With NAFLD in the United States

Population-based studies that estimate awareness of nonalcoholic fatty liver disease (NAFLD) in the United States are scant. We aimed to understand public awareness of NAFLD and its temporal trends. Our study included 11,700 adults (18+ years old) from five National Health and Nutrition Examination Surveys (2007-2016). NAFLD was determined by the improved Fatty Liver Index for the multiethnic U.S. population (US-FLI) in the absence of secondary causes of liver disease. Overall prevalence of NAFLD, hepatitis C virus, and hepatitis B virus were 36.6%, 1.02% and 0.35%, respectively. From 2007-2008 to 2015-2016, awareness of liver disease among adults with NAFLD improved from 4.4% to 6.3% (trend P = 0.026) but 4 to 10 times lower than awareness about viral hepatitis. In 2015-2016, among adults with NAFLD, awareness of liver disease was lower among young adults (aged 18-29 years) compared with those aged ≥ 30 years (0% vs. 6.9%) and lower among non-Hispanic Blacks compared with other races (0.7% vs. 6.6%) (all P < 0.001). In multivariable analysis, young adults (adjusted odds ratio [aOR] = 0.29; confidence interval [CI] 0.10-0.87) and non-Hispanic Blacks (aOR = 0.43; CI 0.20-0.96) were negatively associated with awareness of liver disease among adults with NAFLD, whereas diabetes (aOR = 2.22; CI 1.37-3.58), advanced fibrosis (aOR = 2.34; CI 1.17-4.68), and a higher number of health care visits (aOR = 1.33; CI 1.15-1.50) were positively associated with awareness of liver disease. Nearly 96% of adults with NAFLD in the United States were unaware they had liver disease, especially among young adults and non-Hispanic Blacks. Findings indicate efforts are needed to improve awareness of NAFLD.

Kidney utilization and outcomes of liver transplant recipients who were listed for kidney after liver transplant after the implementation of safety net policy

In 2017, United Network for Organ Sharing (UNOS) established the safety net policy with set criteria for offering kidney transplantation (KT) for patients who developed end-stage renal disease between 60 and 365 days after liver transplant (LT). We provide an update on the impact of the policy. We analyzed UNOS data of liver recipients transplanted between 1987 and 2020 who developed acute kidney injury requiring dialysis within 60 days before or after LT and subsequently listed for KT. We identified 407 patients who were listed for kidney after LT before policy and 248 patients after policy. Median waiting time to KT was shorter after policy (324 days vs. 2827 days). There was a higher proportion of candidates who were listed for subsequent KT within 1-year after policy (94.8% vs. 63.6%). KT rate was also higher after policy (87.7 vs. 30.7 per 100 patient-years at risk). Most importantly, we started to observe a net negative kidney utilization in end-stage liver disease setting (i.e., summation of simultaneous liver kidney and kidney after liver transplant in the first-year after LT has decreased from 1086 to 876 transplants in 2019). Such findings are consistent with a more efficient system and more appropriate allocation of organs.

Genetics, Immunity and Nutrition Boost the Switching from NASH to HCC

Nonalcoholic fatty liver disease (NAFLD) is the leading contributor to the global burden of chronic liver diseases. The phenotypic umbrella of NAFLD spans from simple and reversible steatosis to nonalcoholic steatohepatitis (NASH), which may worsen into cirrhosis and hepatocellular carcinoma (HCC). Notwithstanding, HCC may develop also in the absence of advanced fibrosis, causing a delayed time in diagnosis as a consequence of the lack of HCC screening in these patients. The precise event cascade that may precipitate NASH into HCC is intricate and it entails diverse triggers, encompassing exaggerated immune response, endoplasmic reticulum (ER) and oxidative stress, organelle derangement and DNA aberrancies. All these events may be accelerated by both genetic and environmental factors. On one side, common and rare inherited variations that affect hepatic lipid remodeling, immune microenvironment and cell survival may boost the switching from steatohepatitis to liver cancer, on the other, diet-induced dysbiosis as well as nutritional and behavioral habits may furtherly precipitate tumor onset. Therefore, dietary and lifestyle interventions aimed to restore patients' health contribute to counteract NASH progression towards HCC. Even more, the combination of therapeutic strategies with dietary advice may maximize benefits, with the pursuit to improve liver function and prolong survival.

Systematic review with network meta-analysis: comparative efficacy of pharmacologic therapies for fibrosis improvement and resolution of NASH

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a common cause of chronic liver disease. There is a major need to understand the efficacy of different pharmacological agents for the treatment of NASH.

AIM

To assess the relative rank-order of different pharmacological interventions in fibrosis improvement and NASH resolution.

METHODS

A comprehensive search of several databases was conducted by an experienced librarian. We included randomised controlled-trials (RCTs) comparing pharmacological interventions in patients with biopsy-proven NASH. The primary outcome was ≥1 stage improvement in fibrosis. The secondary outcome was NASH resolution.

RESULTS

A total of 26 RCTs with 23 interventions met the eligibility criteria. Lanifibranor and obeticholic acid had the highest probability of being ranked the most effective intervention for achieving ≥1 stage of fibrosis improvement (SUCRA 0.78) and (SUCRA 0.77), respectively. For NASH resolution, semaglutide, liraglutide and vitamin E plus pioglitazone had the highest probability of being ranked the most effective intervention for achieving NASH resolution (SUCRA 0.89), (SUCRA 0.84) and (SUCRA 0.83), respectively. Lanifibranor, obeticholic acid, pioglitazone and vitamin E were significantly better than placebo in achieving ≥1 stage of fibrosis improvement. Conversely, semaglutide, liraglutide, vitamine E plus pioglitazone, pioglitazone, lanifibranor and obeticholic acid were significantly better than placebo in achieving NASH resolution.

CONCLUSION

These data provide relative rank-order efficacy of various NASH therapies in terms of their improvements in liver fibrosis and NASH resolution. Therapies that have been shown to improve NASH resolution may be combined with therapies that have an antifibrotic effect to further boost treatment response rate in future.

Nonalcoholic Fatty Liver Disease Prevalence Trends Among Adolescents and Young Adults in the United States, 2007-2016

Understanding the burden of NAFLD among adolescents and young adults has become increasingly relevant. Our aim was to estimate the prevalence of NAFLD among adolescents and young adults in the United States. Data were obtained from National Health and Nutrition Examination Survey from 2007-2016. Adolescents and young adults aged 12 to 29 years were included. NAFLD was determined by the U.S. Fatty Liver Index in the absence of secondary causes of liver disease, and the differences in prevalence trends were analyzed based on age, gender, and race. Complete data were available for 4,654 adolescents and young adults (mean age 21 years; 50.9% male; 56.8% White, 20.9% Hispanic, and 13.3% Black). The overall prevalence of NAFLD among adolescents and young adults was 18.5%, ranging from 13.2% among early and middle adolescents (12-17 years) to 18.7% among late adolescents and young adults (18-24 years), to 24.0% among older young adults (25-30 years) (trend P < 0.001). The prevalence of NAFLD was higher for boys than for girls (aged 12-17: 15.1% vs. 11.3%; aged 18-24: 21.1% vs. 16.2%; aged 25-30: 28.7% vs. 19.2%, all P < 0.030). Among all age groups, Hispanics had a higher prevalence of NAFLD than Whites and Blacks (pairwise P < 0.001). Over the study time period, the prevalence of NAFLD among early and middle adolescents and young adults did not change (trend P > 0.80). In contrast, NAFLD prevalence among late adolescents increased (trend P = 0.018). In fact, White and Hispanic late adolescents were the drivers behind this increase in the prevalence of NAFLD. Conclusion: These data indicate an increasing trend in NAFLD prevalence among 18-24-year-olds. These data have important public health and policy implications.

Exogenous Drug Disposition as a Diagnostic Biomarker Strategy for Non-Alcoholic Steatohepatitis

Non-alcoholic steatohepatitis (NASH) is the progressive form of non-alcoholic fatty liver disease (NAFLD) and is diagnosed by a liver biopsy. Due to the invasiveness of a biopsy, the majority of patients with NASH are undiagnosed. Additionally, the prevalence of NAFLD and NASH creates the need for a simple screening method to differentiate patients with NAFLD versus NASH. Non-invasive strategies for diagnosing NAFLD versus NASH have been developed, typically relying on imaging techniques and endogenous biomarker panels. However, each technique has limitations, and none can accurately predict the associated functional impairment of drug metabolism and disposition. The function of several drug metabolizing enzymes and drug transporters have been described in NASH that impacts drug pharmacokinetics. The aim of this review is to give an overview of the existing non-invasive strategies to diagnose NASH, and to propose a novel strategy based on altered pharmacokinetics using an exogenous biomarker whose disposition and elimination pathways are directly impacted by disease progression. Altered disposition of safe and relatively inert exogenous compounds may provide the sensitivity and specificity needed to differentiate patients with NAFLD and NASH to facilitate a direct indication of hepatic impairment on drug metabolism and prevent subsequent adverse drug reactions. Significance Statement This review provides an overview of the main non-invasive techniques (imaging and panels of biomarkers) used to diagnose non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) along with a biopsy. Pharmacokinetic changes have been identified in NASH and this review proposes a new approach to predict NASH and the related risk of adverse drug reactions, based on the assessment of drug elimination disruption using exogenous biomarkers.

Oxy210, a novel inhibitor of hedgehog and TGF-β signalling, ameliorates hepatic fibrosis and hypercholesterolemia in mice

AIMS

Non-alcoholic steatohepatitis (NASH) is associated with increased overall morbidity and mortality in non-alcoholic fatty liver disease (NAFLD) patients. Liver fibrosis is the strongest prognostic factor for clinical outcomes, liver-related mortality and liver transplantation. Currently, no single therapy or medication for NASH has been approved by the U.S. Food and Drug Administration (FDA). Oxy210, an oxysterol derivative, displays the unique property of antagonizing both Hedgehog (Hh) and transforming growth factor-beta (TGF-β) signalling in primary human hepatic stellate cells (HSC). We hypothesized that inhibition of both Hh and TGF-β signalling by Oxy210 could reduce hepatic fibrosis in NASH. In this study, we examined the therapeutic potential of Oxy210 on NASH in vivo.

METHODS

We examined the effect of Oxy210 treatment on Hh and TGF-β pathways in HSC. The efficacy of Oxy210 on liver fibrosis was tested in a 'humanized' hyperlipidemic mouse model of NASH that has high relevance to human pathology.

APPROACH AND RESULTS

We show that Oxy210 inhibits both Hh and TGF-β pathways in human HSC and attenuates baseline and TGF-β-induced expression of pro-fibrotic genes in vitro. Oral delivery of Oxy210 in food resulted in significant liver exposure and significantly reduced hepatic fibrosis in mice over the course of the 16-week study with no apparent safety issues. Additionally, we observed several benefits related to NASH phenotype: (a) reduced plasma pro-inflammatory cytokine and the corresponding hepatic gene expression; (b) reduced pro-fibrotic cytokine and inflammasome gene expression in the liver; (c) reduced apoptosis in the liver; (d) reduced hepatic unesterified cholesterol accumulation; and (e) reduced plasma total and unesterified cholesterol levels.

CONCLUSIONS

Oxy210 effectively ameliorated hepatic fibrosis and inflammation and improved hypercholesterolemia in mice. Our findings suggest that Oxy210 and related analogues are a new class of drug candidates that may serve as potential therapeutics candidates for NASH.

Preparing for the NASH epidemic: A call to action

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common conditions with a rising burden. Yet there are significant management gaps between clinical guidelines and practice in patients with NAFLD and NASH. Further, there is no single global guiding strategy for the management of NAFLD and NASH. The American Gastroenterological Association, in collaboration with 7 professional associations, convened an international conference comprising 32 experts in gastroenterology, hepatology, endocrinology, and primary care providers from the United States, Europe, Asia, and Australia. Conference content was informed by the results of a national NASH Needs Assessment Survey. The participants reviewed and discussed published literature on global burden, screening, risk stratification, diagnosis, and management of individuals with NAFLD, including those with NASH. Participants identified promising approaches for clinical practice and prepared a comprehensive, unified strategy for primary care providers and relevant specialists encompassing the full spectrum of NAFLD/NASH care. They also identified specific high-yield targets for clinical research and called for a unified, international public health response to NAFLD and NASH.

Preparing for the NASH Epidemic: A Call to Action

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common conditions with a rising burden. Yet there are significant management gaps between clinical guidelines and practice in patients with NAFLD and NASH. Further, there is no single global guiding strategy for the management of NAFLD and NASH. The American Gastroenterological Association, in collaboration with 7 professional associations, convened an international conference comprising 32 experts in gastroenterology, hepatology, endocrinology, and primary care providers from the United States, Europe, Asia, and Australia. Conference content was informed by the results of a national NASH Needs Assessment Survey. The participants reviewed and discussed published literature on global burden, screening, risk stratification, diagnosis, and management of individuals with NAFLD, including those with NASH. Participants identified promising approaches for clinical practice and prepared a comprehensive, unified strategy for primary care providers and relevant specialists encompassing the full spectrum of NAFLD/NASH care. They also identified specific high-yield targets for clinical research and called for a unified, international public health response to NAFLD and NASH.

Glycemic Control Predicts Severity of Hepatocyte Ballooning and Hepatic Fibrosis in Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

Whether glycemic control, as opposed to diabetes status, is associated with the severity of NAFLD is open for study. We aimed to evaluate whether degree of glycemic control in the years preceding liver biopsy predicts the histological severity of NASH.

APPROACH AND RESULTS

Using the Duke NAFLD Clinical Database, we examined patients with biopsy-proven NAFLD/NASH (n = 713) and the association of liver injury with glycemic control as measured by hemoglobin A1c (HbA1c). The study cohort was predominantly female (59%) and White (84%) with median (interquartile range) age of 50 (42, 58) years; 49% had diabetes (n = 348). Generalized linear regression models adjusted for age, sex, race, diabetes, body mass index, and hyperlipidemia were used to assess the association between mean HbA1c over the year preceding liver biopsy and severity of histological features of NAFLD/NASH. Histological features were graded and staged according to the NASH Clinical Research Network system. Group-based trajectory analysis was used to examine patients with at least three HbA1c (n = 298) measures over 5 years preceding clinically indicated liver biopsy. Higher mean HbA1c was associated with higher grade of steatosis and ballooned hepatocytes, but not lobular inflammation. Every 1% increase in mean HbA1c was associated with 15% higher odds of increased fibrosis stage (OR, 1.15; 95% CI, 1.01, 1.31). As compared with good glycemic control, moderate control was significantly associated with increased severity of ballooned hepatocytes (OR, 1.74; 95% CI, 1.01, 3.01; P = 0.048) and hepatic fibrosis (HF; OR, 4.59; 95% CI, 2.33, 9.06; P < 0.01).

CONCLUSIONS

Glycemic control predicts severity of ballooned hepatocytes and HF in NAFLD/NASH, and thus optimizing glycemic control may be a means of modifying risk of NASH-related fibrosis progression.

Preparing for the NASH Epidemic: A Call to Action

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common conditions with a rising burden. Yet there are significant management gaps between clinical guidelines and practice in patients with NAFLD and NASH. Further, there is no single global guiding strategy for the management of NAFLD and NASH. The American Gastroenterological Association, in collaboration with 7 professional associations, convened an international conference comprising 32 experts in gastroenterology, hepatology, endocrinology, and primary care providers from the United States, Europe, Asia, and Australia. Conference content was informed by the results of a national NASH Needs Assessment Survey. The participants reviewed and discussed published literature on global burden, screening, risk stratification, diagnosis, and management of individuals with NAFLD, including those with NASH. Participants identified promising approaches for clinical practice and prepared a comprehensive, unified strategy for primary care providers and relevant specialists encompassing the full spectrum of NAFLD/NASH care. They also identified specific high-yield targets for clinical research and called for a unified, international public health response to NAFLD and NASH.

Preparing for the NASH epidemic: A call to action

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common conditions with a rising burden. Yet there are significant management gaps between clinical guidelines and practice in patients with NAFLD and NASH. Further, there is no single global guiding strategy for the management of NAFLD and NASH. The American Gastroenterological Association, in collaboration with 7 professional associations, convened an international conference comprising 32 experts in gastroenterology, hepatology, endocrinology, and primary care providers from the United States, Europe, Asia, and Australia. Conference content was informed by the results of a national NASH Needs Assessment Survey. The participants reviewed and discussed published literature on global burden, screening, risk stratification, diagnosis, and management of individuals with NAFLD, including those with NASH. Participants identified promising approaches for clinical practice and prepared a comprehensive, unified strategy for primary care providers and relevant specialists encompassing the full spectrum of NAFLD/NASH care. They also identified specific high-yield targets for clinical research and called for a unified, international public health response to NAFLD and NASH.

Transcriptomic Cross-Species Analysis of Chronic Liver Disease Reveals Consistent Regulation Between Humans and Mice

Mouse models are frequently used to study chronic liver diseases (CLDs). To assess their translational relevance, we quantified the similarity of commonly used mouse models to human CLDs based on transcriptome data. Gene‐expression data from 372 patients were compared with data from acute and chronic mouse models consisting of 227 mice, and additionally to nine published gene sets of chronic mouse models. Genes consistently altered in humans and mice were mapped to liver cell types based on single‐cell RNA‐sequencing data and validated by immunostaining. Considering the top differentially expressed genes, the similarity between humans and mice varied among the mouse models and depended on the period of damage induction. The highest recall (0.4) and precision (0.33) were observed for the model with 12‐months damage induction by CCl₄ and by a Western diet, respectively. Genes consistently up‐regulated between the chronic CCl₄ model and human CLDs were enriched in inflammatory and developmental processes, and mostly mapped to cholangiocytes, macrophages, and endothelial and mesenchymal cells. Down‐regulated genes were enriched in metabolic processes and mapped to hepatocytes. Immunostaining confirmed the regulation of selected genes and their cell type specificity. Genes that were up‐regulated in both acute and chronic models showed higher recall and precision with respect to human CLDs than exclusively acute or chronic genes. Conclusion: Similarly regulated genes in human and mouse CLDs were identified. Despite major interspecies differences, mouse models detected 40% of the genes significantly altered in human CLD. The translational relevance of individual genes can be assessed at https://saezlab.shinyapps.io/liverdiseaseatlas/.

Independent Predictors of Mortality Among Patients With NAFLD Hospitalized With COVID-19 Infection

The impact of the coronavirus disease 2019 (COVID-19) pandemic among patients with chronic liver disease is unknown. Given the high prevalence of nonalcoholic fatty liver disease (NAFLD), we determined the predictors of mortality and hospital resource use among patients with NAFLD admitted with COVID-19 by using electronic medical records data for adult patients with COVID-19 hospitalized in a multihospital health system who were discharged between March and December 2020. NAFLD was diagnosed by imaging or liver biopsy without other liver diseases. Charlson's comorbidity index (CCI) and Elixhauser comorbidity index (ECI) scores were calculated. In the study sample, among the 4,835 patients hospitalized for COVID-19, 553 had NAFLD (age: 55 ± 16 years, 51% male, 17% White, 11% Black, 58% Hispanic, 8% Asian, 5% from congregated living, 58% obese, 15% morbid obesity [body mass index ≥ 40], 51% type 2 diabetes, 63% hypertension, mean [SD] baseline CCI of 3.9 [3.2], and baseline ECI of 13.4 [11.3]). On admission, patients with NAFLD had more respiratory symptoms, higher body temperature and heart rate, higher alanine aminotransferase and aspartate aminotransferase than non-NAFLD controls (n = 2,736; P < 0.05). Of the patients with NAFLD infected with COVID-19, 3.9% experienced acute liver injury. The NAFLD group had significantly longer length of stay, intensive care unit use, and mechanical ventilation, with a crude inpatient mortality rate of 11%. In multivariate analysis, independent predictors of inpatient mortality among patients with NAFLD infected with COVID-19 were older age, morbid obesity, ECI score ≥ 11, higher Fibrosis-4 Index (FIB-4) score, and oxygen saturation <90% (all P < 0.05), but not sex, race/ethnicity, or any individual comorbidity (all P > 0.05). Conclusion: Patients with NAFLD infected with COVID-19 tend to be sicker on admission and require more hospital resource use. Independent predictors of mortality included higher FIB-4 and multimorbidity scores, morbid obesity, older age, and hypoxemia on admission.

Advanced glycation end product: A potential biomarker for risk stratification of non-alcoholic fatty liver disease in ELSA-Brasil study

BACKGROUND

Liver diseases are associated with the excess formation of advanced glycation end products (AGEs), which induce tissue inflammation and oxidative damage. However, the trend of oxidative marker levels according to the steatosis grade in non-alcoholic fatty liver disease (NAFLD) is unclear.

AIM

To compare serum AGE levels between participants with NAFLD accordingly to steatosis severity in the baseline ELSA-Brasil population.

METHODS

In 305 individuals at baseline ELSA-Brasil, NAFLD-associated steatosis was classified by ultrasound hepatic attenuation. The participants were grouped according to the severity of steatosis: mild and moderate/severe pooled. The measurement of serum fluorescent AGE concentrations was based on spectrofluorimetric detection. Serum AGE content and clinical and laboratory characteristics of the participants were compared between groups. The correlation between serum AGE levels and the grade of steatosis was analyzed. Logistic regression analysis was used to investigate the relationship between serum AGE levels and steatosis severity. A P value < 0.05 was considered statistically significant.

RESULTS

According to the steatosis severity spectrum in NAFLD, from mild to moderate/severe, individuals with the most severe steatosis grade had a higher incidence of metabolic syndrome (63% vs 34%, P ≤ 0.001), diabetes mellitus (37% vs 14%, P ≤ 0.001), and high cholesterol levels (51% vs 33%, P < 0.001). Moreover, individuals with increasing severity of steatosis presented increasing waist circumference, body mass index, systolic and diastolic blood pressure, fasting blood glucose, glycated hemoglobin, insulin, triglycerides, alanine aminotransferase, gamma-glutamyl transferase, C-reactive protein, and uric acid levels and lower high-density lipoprotein. Higher serum AGE content was present in the moderate/severe group of individuals than in the mild group (P = 0.008). In addition, the serum AGE levels were correlated with the steatosis grade in the overall sample (rho = 0.146, P = 0.010). Logistic regression analysis, after adjusting for confounding variables, showed that subjects with higher serum AGE content had a 4.6-fold increased chance of having moderate or severe steatosis when compared to low levels of serum AGEs. According to the results of the receiver operator characteristic curves analyses (areas under the curve, AUC = 0.83), AGEs could be a good marker of steatosis severity in patients with NAFLD and might be a potential biomarker in predicting NAFLD progression, strengthening the involvement of AGE in NAFLD pathogenesis.

CONCLUSION

NAFLD-associated steatosis was associated with serum AGE levels; therefore, plasmatic fluorescent AGE quantification by spectroscopy could be a promising alternative method to monitor progression from mild to severe NAFLD accordingly to steatosis grade.

Epidemiology of non-alcoholic fatty liver disease and hepatocellular carcinoma

The prevalence of hepatocellular carcinoma (HCC) is increasing worldwide, whereas that of most other cancers is decreasing. Non-alcoholic fatty liver disease (NAFLD), which has increased with the epidemics of obesity and type 2 diabetes, increases the risk of HCC. Interestingly, NAFLD-associated HCC can develop in patients with or without cirrhosis. A lack of awareness about NAFLD-related HCC has led to delays in diagnosis. Therefore, a large number of patients with HCC are diagnosed with advanced-stage HCC with low 5-year survival. In this context, increasing awareness of NAFLD and NAFLD-related HCC may lead to earlier diagnosis and more effective interventions.

NAFLD and Liver Fibrosis Are Not Associated With Reduced Femoral Bone Mineral Density in the General US Population

CONTEXT

It is still debated whether nonalcoholic fatty liver disease (NAFLD) may be a risk factor for reduced bone mineral density (BMD), and it is not known whether liver fibrosis, the major predictor of future development of liver-related events in NAFLD, has an influence on BMD.

OBJECTIVE

To assess whether liver steatosis and fibrosis are associated with reduced BMD in the general US population.

METHODS

We performed a cross-sectional analysis of the population-based 2017-2018 cycle of the National Health and Nutrition Examination Survey (NHANES), in which vibration-controlled transient elastography (VCTE) and dual-energy x-ray absorptiometry (DXA) of the femoral neck were simultaneously available. Controlled attenuation parameter (CAP) ≥ 274 dB/m was considered indicative of liver steatosis, while a median liver stiffness measurement (LSM) ≥ 8 kPa indicated the presence of significant liver fibrosis. We included all participants older than 50 years with reliable VCTE and femoral neck DXA results (925 men and 859 women). The main outcome measures were femoral neck BMD values indicative of osteopenia or osteoporosis.

RESULTS

Steatosis and significant fibrosis were highly prevalent in the studied population, being present in 53.1% and 9.6% of men and 44.2% and 8.0% of women, respectively. In univariate analysis, liver steatosis was associated with a lower prevalence of osteoporosis in both men and women, while no difference was noted according to the degree of liver fibrosis. After adjustment for potential confounders, including age, BMI, race/ethnicity, cigarette smoking, and diabetes, neither CAP nor LSM were significantly associated with reduced BMD in both sexes.

CONCLUSION

Liver steatosis and fibrosis are not associated with femoral DXA-based diagnosis of osteopenia or osteoporosis in the US population older than 50 years.

Changing trends in liver transplantation indications in Saudi Arabia: from hepatitis C virus infection to nonalcoholic fatty liver disease

Background

Several trend analyses on liver transplantation (LT) indications have been published in the U.S. and in other countries, but there are limited data on LT indication trends in Saudi Arabia (SA), especially since the availability of direct-acting antivirals (DAAs) treatment for hepatitis C virus (HCV). This study aimed to analyze trends in the frequency of LT indications among LT recipients in SA over a 19-year period and examine associations between etiologic-specific trends and clinicodemographic characteristics.

Methods

This retrospective study analyzed clinical and surgical data of adult patients (n = 1009) who underwent LT at the King Faisal Specialist Hospital & Research Center (Riyadh, SA) between 2001 and 2019. Spearman’s rank correlation, Poisson regression, and Joinpoint regression analysis were employed to assess changes in LT etiologic trends.

Results

In the first period (2001–2010), the main LT indications were HCV (41.9%) and hepatitis B virus (HBV) (21.1%), but nonalcoholic steatohepatitis (NASH) (29.7%) surpassed HCV (23.7%) as the leading LT indication in the second period (2011–2019); and the trends were significant in correlation analyses [incidence rate ratio (IRR) = 1.09 (1.06–1.13) for NASH; IRR = 0.93 (0.91–0.95) for HCV]. In the Joinpoint regression analysis, increases in NASH from 2006 to 2012 (+ 32.1%) were statistically significant, as were the decreases in HCV from 2004 to 2007 (− 19.6%) and from 2010 to 2019 (− 12.1%). Similar patterns were observed in LT etiological comparisons before and after the availability of DAAs and within hepatocellular carcinoma stratifications.

Conclusions

Trends in the epidemiology of LT indications among LT recipients in SA have changed over a 19-year period. Most notably, NASH has eclipsed HCV in the country due to the effective treatment strategies for HCV. These trends in NASH now need an aggressive public health response to minimize and avert future onset of additional clinical and economic strains on health care systems and LT centers in SA.

The Mortality and Overall Survival Trends of Primary Liver Cancer in the United States

BACKGROUND

Recent trends of hepatocellular carcinoma (HCC) mortality and outcome remain unknown in the United States (US). We investigated the recent trends of primary liver cancer (excluding intrahepatic cholangiocarcinoma) mortality and HCC stage, treatment, and overall survival (OS) in the US.

METHODS

US Cancer Mortality database was analyzed to investigate the trend of primary liver cancer mortality. We analyzed the SEER 18 database to assess the temporal trend of tumor size, stage, treatment, and OS of HCC. Cox regression analysis investigated the association between HCC diagnosis year and OS. All statistical tests were 2-sided.

RESULTS

During 2000-2018, liver cancer mortality rates increased until 2013, plateaued during 2013-2016 (annual percent change [APC] = 0.1%/yr, 95% confidence interval [CI] = -2.1% to 2.4%; P=0.92), and started to decline during 2016-2018 (APC = -1.5%/yr, 95% CI= -3.2% to 0.2%; P=0.08). However, mortality continues to increase in American Indians/Alaska Natives, individuals aged 65 or older, and in 33 states. There was a 0.61% (95% CI = 0.53% to 0.69%; P<0.001) increase in localized stage HCC and 0.86 mm (95% CI= -1.10 to -0.62; P<0.001) decrease in median tumor size per year. One-year OS rate increased from 36.3% (95% CI = 34.3% to 38.3%) to 58.1% (95% CI = 56.9% to 59.4%) during 2000-2015, and five-year OS rate almost doubled from 11.7% (95% CI = 10.4% to 13.1%) to 21.3% (95% CI = 20.2% to 22.4%) during 2000-2011. Diagnosis year (per year) (adjusted hazard ratio = 0.96; 95% CI = 0.96 to 0.97) was independently associated with OS in multivariable analysis.

CONCLUSIONS

Primary liver cancer mortality rates have started to decline in the US with demographic and state-level variation. With an increasing detection of localized HCC, the OS of HCC has improved over the past decades.

Kaempferol-3-O-Glucuronide Ameliorates Non-Alcoholic Steatohepatitis in High-Cholesterol-Diet-Induced Larval Zebrafish and HepG2 Cell Models via Regulating Oxidation Stress

NAFLD (non-alcoholic fatty liver disease) is one of the most prominent liver diseases in the world. As a metabolic-related disease, the development of NAFLD is closely associated with various degrees of lipid accumulation, oxidation, inflammation, and fibrosis. Ilex chinensis Sims is a form of traditional Chinese medicine which is used to treat bronchitis, burns, pneumonia, ulceration, and chilblains. Kaempferol-3-O-glucuronide (K3O) is a natural chemical present in Ilex chinensis Sims. This study was designed to investigate the antioxidative, fat metabolism-regulating, and anti-inflammatory potential of K3O. A high-cholesterol diet (HCD) was used to establish steatosis in larval zebrafish, whereby 1mM free fatty acid (FFA) was used to induce lipid accumulation in HepG2 cells, while H₂O₂ was used to induce oxidative stress in HepG2. The results of this experiment showed that K3O reduced lipid accumulation and the level of reactive oxygen species (ROS) both in vivo (K3O, 40 μM) and in vitro (K3O, 20 μM). Additionally, K3O (40 μM) reduced neutrophil aggregation in vivo. K3O (20 μM) also decreased the level of malondialdehyde (MDA) and significantly increased the level of glutathione peroxidase (GSH-px) in both the HCD-induced larval zebrafish model and H₂O₂-exposed HepG2 cells. In the mechanism study, keap1, nrf2, tnf-α, and il-6 mRNA were all significantly reversed by K3O (20 μM) in zebrafish. Changes in Keap1 and Nrf2 mRNA expression were also detected in H₂O₂-exposed HepG2 cells after they were treated with K3O (20 μM). In conclusion, K3O exhibited a reduction in oxidative stress and lipid peroxidation, and this may be related to the Nrf2/Keap1 pathway in the NAFLD larval zebrafish model.

Unraveling the Role of Hypothyroidism in Non-alcoholic Fatty Liver Disease Pathogenesis: Correlations, Conflicts, and the Current Stand

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common causes of chronic liver diseases globally. Because thyroid hormones play a crucial role in lipid metabolism, thyroid dysfunction has been implicated in NAFLD pathogenesis in the past decade, with hypothyroidism-induced NAFLD being regarded as a distinct disease entity. However, there has been no common consensus yet, and several studies have found contradictory results. Hence, we conducted this systematic review to represent the current view on the role of hypothyroidism (HT) and individual thyroid function parameters such as thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) in NAFLD pathogenesis. We searched PubMed, PubMed Central, and Semantic Scholar databases from inception until January 2021 to identify relevant observational (case-control, cross-sectional, and longitudinal) studies. A total of 699 articles were recognized through our database search. After applying the eligibility criteria and performing quality assessment, 10 studies involving 42,227 participants were included in the final systematic review. Each of these studies assessed different thyroid function parameters, and NAFLD was found to be associated with HT in two studies, elevated TSH in three studies, suppressed T4 in three studies, elevated T3 in one study, and elevated TPOAb in one study. There was also a wide heterogeneity in HT definition, study population characteristics, and study design among these studies, making a direct comparison difficult. Because the recognition of HT-induced NAFLD has possible diagnostic, therapeutic, and prognostic implications, we recommend that comprehensive, long-term prospective studies be carried out to determine if HT or thyroid function parameters are causally associated with NAFLD.

The Growing Burden of Disability Related to Chronic Liver Disease in the United States: Data From the Global Burden of Disease Study 2007-2017

Chronic liver disease (CLD) causes significant morbidity and mortality in the United States with regional variations. Comparable and consistent state-level measures of CLD-related morbidity and disability among U.S. states have not been well studied. Our aim was to assess the CLD burden within the United States between 2007 and 2017 based on the most common causes of CLD: hepatitis B virus, hepatitis C virus (HCV), alcoholic liver disease (ALD), and nonalcoholic fatty liver disease (NAFLD). The Global Burden of Disease database was used for the years 2007-2017. International Classification of Diseases, Tenth Revision, codes were used to identify liver cancer (LC) and cirrhosis. Disability-adjusted life years (DALYs) were computed by the summation of years of life lost and years lived with disability. All rates reported here were age-standardized rates per 100,000 population. In 2017, there were 167,324 incident CLDs, 21% from LC and 79% from cirrhosis; this number was 30% higher than in 2007. The highest rate increases were seen in Kentucky, New York, and Pennsylvania. In 2017, there were 90,046 CLD-related deaths, which was 34% higher than in 2007. Highest rank increases were seen in Kentucky, Montana, and Washington. The rate of CLD incidence and death due to NAFLD was higher than other causes of CLD. In 2017, CLD caused 2.33 million DALYs, which was 27% higher than in 2007 and was mainly driven by HCV (37.2%), ALD (27.7%), and NAFLD (10.6%). California, Texas, and Florida had the highest DALYs; however, the highest CLD-DALY rates per 100,000 population were seen in New Mexico, District of Columbia, and Oklahoma. Conclusion: The CLD-related burden is increasing in the majority of U.S. states at an unprecedented rate. The impact of this burden on individual states is heterogeneous, and there are important disparities among states that merit further investigation.

From hepatitis A to E: A critical review of viral hepatitis

Viral infections affecting the liver have had an important impact on humanity, as they have led to significant morbidity and mortality in patients with acute and chronic infections. Once an unknown etiology, the discovery of the viral agents triggered interest of the scientific community to establish the pathogenesis and diagnostic modalities to identify the affected population. With the rapid scientific and technological advances in the last centuries, controlling and even curing the infections became a possibility, with a large focus on preventive medicine through vaccination. Hence, a comprehensive understanding of hepatitis A, B, C, D and E is required by primary care physicians and gastroenterologists to provide care to these patients. The review article describes the epidemiology, pathogenesis, clinical presentation, diagnostic tools and current medication regimens, with a focus on upcoming treatment options and the role of liver transplantation.

Long-term mortality risk stratification of liver transplant recipients: real-time application of deep learning algorithms on longitudinal data

BACKGROUND

Survival of liver transplant recipients beyond 1 year since transplantation is compromised by an increased risk of cancer, cardiovascular events, infection, and graft failure. Few clinical tools are available to identify patients at risk of these complications, which would flag them for screening tests and potentially life-saving interventions. In this retrospective analysis, we aimed to assess the ability of deep learning algorithms of longitudinal data from two prospective cohorts to predict complications resulting in death after liver transplantation over multiple timeframes, compared with logistic regression models.

METHODS

In this machine learning analysis, model development was done on a set of 42 146 liver transplant recipients (mean age 48·6 years [SD 17·3]; 17 196 [40·8%] women) from the Scientific Registry of Transplant Recipients (SRTR) in the USA. Transferability of the model was further evaluated by fine-tuning on a dataset from the University Health Network (UHN) in Canada (n=3269; mean age 52·5 years [11·1]; 1079 [33·0%] women). The primary outcome was cause of death, as recorded in the databases, due to cardiovascular causes, infection, graft failure, or cancer, within 1 year and 5 years of each follow-up examination after transplantation. We compared the performance of four deep learning models against logistic regression, assessing performance using the area under the receiver operating characteristic curve (AUROC).

FINDINGS

In both datasets, deep learning models outperformed logistic regression, with the Transformer model achieving the highest AUROCs in both datasets (p<0·0001). The AUROC for the Transformer model across all outcomes in the SRTR dataset was 0·804 (99% CI 0·795-0·854) for 1-year predictions and 0·733 (0·729-0·769) for 5-year predictions. In the UHN dataset, the AUROC for the top-performing deep learning model was 0·807 (0·795-0·842) for 1-year predictions and 0·722 (0·705-0·764) for 5-year predictions. AUROCs ranged from 0·695 (0·680-0·713) for prediction of death from infection within 5 years to 0·859 (0·847-0·871) for prediction of death by graft failure within 1 year.

INTERPRETATION

Deep learning algorithms can incorporate longitudinal information to continuously predict long-term outcomes after liver transplantation, outperforming logistic regression models. Physicians could use these algorithms at routine follow-up visits to identify liver transplant recipients at risk for adverse outcomes and prevent these complications by modifying management based on ranked features.

FUNDING

Canadian Donation and Transplant Research Program, CIFAR AI Chairs Program.

Quantitative, noninvasive MRI characterization of disease progression in a mouse model of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is an increasing cause of chronic liver disease characterized by steatosis, inflammation, and fibrosis which can lead to cirrhosis, hepatocellular carcinoma, and mortality. Quantitative, noninvasive methods for characterizing the pathophysiology of NASH at both the preclinical and clinical level are sorely needed. We report here a multiparametric magnetic resonance imaging (MRI) protocol with the fibrogenesis probe Gd-Hyd to characterize fibrotic disease activity and steatosis in a common mouse model of NASH. Mice were fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) to induce NASH with advanced fibrosis. Mice fed normal chow and CDAHFD underwent MRI after 2, 6, 10 and 14 weeks to measure liver T1, T2*, fat fraction, and dynamic T1-weighted Gd-Hyd enhanced imaging of the liver. Steatosis, inflammation, and fibrosis were then quantified by histology. NASH and fibrosis developed quickly in CDAHFD fed mice with strong correlation between morphometric steatosis quantification and liver fat estimated by MRI (r = 0.90). Sirius red histology and collagen quantification confirmed increasing fibrosis over time (r = 0.82). Though baseline T1 and T2* measurements did not correlate with fibrosis, Gd-Hyd signal enhancement provided a measure of the extent of active fibrotic disease progression and correlated strongly with lysyl oxidase expression. Gd-Hyd MRI accurately detects fibrogenesis in a mouse model of NASH with advanced fibrosis and can be combined with other MR measures, like fat imaging, to more accurately assess disease burden.

Orthotopic liver transplant in the pregnant recipient: A systematic review of preoperative management and maternal and fetal outcomes

Severe liver dysfunction requiring transplantation is a major event at any stage of life, but for those requiring liver transplantation while pregnant, two lives hang in the balance. Available evidence on this relatively rare event consists solely of case reports and have yet to be reviewed or synthesized. We performed a systematic literature review and analyzed reports of 22 patients who underwent liver transplantation during pregnancy. This review describes the reported etiologies of hepatic failure in pregnant patients requiring transplantation, perioperative anesthetic management techniques, and the maternal and fetal clinical outcomes.

Diversity in NAFLD: A Review of Manifestations of Nonalcoholic Fatty Liver Disease in Different Ethnicities Globally

Globally, the rise in prevalence of obesity and metabolic syndrome as a whole has been linked to increased access to processed foods, such as refined sugars and saturated fats. Consequently, nonalcoholic fatty liver disease (NAFLD) is on the rise in both developed and developing nations. However, much is still unknown on the NAFLD phenotype with regards to the effect of ethnic diversity. Despite similarities in dietary habits, it appears that certain ethnicities are more protected against NAFLD than others. However, manifestations of the same genetic polymorphisms in different groups of people increase those individuals' predisposition to NAFLD. Diets from different regions have been associated with a lower prevalence of NAFLD and have even been linked to regression of hepatic steatosis. Socioeconomic variations amongst different regions of the world also contribute to NAFLD prevalence and associated complications. Thus, a thorough understanding of ethnic variability in NAFLD is essential to tailoring treatment recommendations to patients of different backgrounds.

Pathophysiology of NASH in endocrine diseases

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. NAFLD encompasses a whole spectrum ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. The latter can lead to hepatocellular carcinoma. Furthermore, NASH is the most rapidly increasing indication for liver transplantation in western countries and therefore represents a global health issue. The pathophysiology of NASH is complex and includes multiple parallel hits. NASH is notably characterized by steatosis as well as evidence of hepatocyte injury and inflammation, with or without fibrosis. NASH is frequently associated with type 2 diabetes and conditions associated with insulin resistance. Moreover, NASH may also be found in many other endocrine diseases such as polycystic ovary syndrome, hypothyroidism, male hypogonadism, growth hormone deficiency or glucocorticoid excess, for example. In this review, we will discuss the pathophysiology of NASH associated with different endocrinopathies.

Maladaptive regeneration - the reawakening of developmental pathways in NASH and fibrosis

With the rapid expansion of the obesity epidemic, nonalcoholic fatty liver disease is now the most common chronic liver disease, with almost 25% global prevalence. Nonalcoholic fatty liver disease ranges in severity from simple steatosis, a benign 'pre-disease' state, to the liver injury and inflammation that characterize nonalcoholic steatohepatitis (NASH), which in turn predisposes individuals to liver fibrosis. Fibrosis is the major determinant of clinical outcomes in patients with NASH and is associated with increased risks of cirrhosis and hepatocellular carcinoma. NASH has no approved therapies, and liver fibrosis shows poor response to existing pharmacotherapy, in part due to an incomplete understanding of the underlying pathophysiology. Patient and mouse data have shown that NASH is associated with the activation of developmental pathways: Notch, Hedgehog and Hippo-YAP-TAZ. Although these evolutionarily conserved fundamental signals are known to determine liver morphogenesis during development, new data have shown a coordinated and causal role for these pathways in the liver injury response, which becomes maladaptive during obesity-associated chronic liver disease. In this Review, we discuss the aetiology of this reactivation of developmental pathways and review the cell-autonomous and cell-non-autonomous mechanisms by which developmental pathways influence disease progression. Finally, we discuss the potential prognostic and therapeutic implications of these data for NASH and liver fibrosis.

Recent updates on the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immunoinflammatory chronic liver disease with dynamic and rather heterogeneous disease manifestations. A trend of increasing prevalence of AIH has been observed worldwide, along with a relative increase in the percentage of male patients. AIH is characterized and diagnosed based on serum biochemistry and liver histology: elevated aminotransferases and serum immunoglobulin G (IgG), the presence of serum anti-nuclear antibody or anti-smooth muscle antibody, and interface lympho-plasmacytic hepatitis. Clinical manifestations differ among disease subtypes with distinct time-frames, i.e., AIH with a chronic insidious onset, and acute-onset AIH (the diagnosis of which is often challenging due to the lack of typical serum findings). The absence of disease-specific biomarkers or histological findings may expand the disease phenotype into drug-induced AIH-like liver injury. Corticosteroids and azathioprine are recommended first-line treatments for AIH. The complete normalization of aminotransferases and serum IgG is an essential treatment response to ensure long-term overall survival. An incomplete response or intolerance to these drugs is considered an indication for second-line treatment, especially with mycophenolate mofetil. Life-long maintenance treatment is required for the majority of patients, but the few who achieve prolonged and stringent biochemical remission with lower alanine aminotransferase and IgG within the normal range may be able to discontinue the medications. In the future, the quality of life of AIH patients should be managed by personalized medicine, including the appropriate selection and dosing of first-line therapy and perhaps alternating with potential therapeutics, and the prediction of the success of treatment withdrawal.

The transcontinental variability of nonalcoholic fatty liver disease

AIM

To compare the phenotype of lean versus overweight (OW) and obese (OB) subjects with non-alcoholic fatty liver disease (NAFLD) across multiple continents.

METHODS

A retrospective study of histologically defined subjects from a single center each in France (Fr), Brazil (Br), India (In) and United States (US) was performed.

RESULTS

A total of 70 lean [body mass index (BMI) < 25 kg/m²] subjects (Fr:Br:In:US: 16:19:22:13) with NAFLD were compared to 136 OW (BMI > 25 kg/m², BMI < 29 kg/m²) (n = 28:33:52:23) and 224 OB subjects (BMI > 29 kg/m²) (n = 81:11:22:103). Lean French subjects had the lowest incidence of type 2 diabetes while those from Brazil (P < 0.01) had the highest. Lean subjects had similar low-density lipoprotein-cholesterol, but higher high-density lipoprotein-cholesterol compared to obese subjects in all regions. In both lean and obese subjects, there were both insulin-sensitive and insulin-resistant subjects. Lean French subjects were most insulin-sensitive while those from Brazil were mostly insulin-resistant. For each weight category, subjects from India were more insulin-sensitive than those from other regions. Disease activity increased from lean to overweight to obese in France but was similar across weight categories in other regions.

CONCLUSION

The phenotype of NAFLD in lean subjects varies by region. Some obese subjects with NAFLD are insulin-sensitive. We hypothesize that genetics and region-specific disease modifiers account for these differences.