Development of hepatocellular carcinoma in Japanese patients with biopsy-proven non-alcoholic fatty liver disease: Association between PNPLA3 genotype and hepatocarcinogenesis/fibrosis progression

Risk factors of hepatocellular carcinoma associated with nonalcoholic fatty liver disease: Systematic review and meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is currently an important chronic liver disease threatening human life and health.

OBJECTIVE

To investigate the risk factors of hepatocellular carcinoma (HCC) associated with nonalcoholic fatty liver disease (NAFLD) by systematic review.

METHODS

We conducted a systematic review and meta-analysis. A systematic search of Chinese and English databases (PubMed, Web of Science, Cochrane Library, China national knowledge infrastructure (CNKI), Wanfang database, and VIP database) was performed until June 30, 2023. Studies were included to investigate the risk factors for HCC in patients with NAFLD. Quality evaluation was performed using the Newcastle-Ottawa Literature Quality Evaluation Scale, and then hazard ratios (HRs) for different influencing factors were combined.

RESULTS

We reviewed the results of 12 high-quality cohort studies involving 738,934 patients with NAFLD and 1,480 developed HCC. A meta-analysis based on a random-effects model showed that advanced age (HR = 1.81, 95% CI: 1.51-2.17), male gender (HR = 2.51, 95% CI: 1.67-3.78), hypertension (HR = 1.87, 95% CI: 1.05-3.33), and diabetes (HR = 2.27, 95% CI: 1.63-3.16) were risk factors for HCC in NAFLD, and the differences were statistically significant. However, there was no statistically significant effect of current smoking (HR = 1.45, 95% CI: 0.72-2.92) and dyslipidemia (HR = 1.03, 95% CI: 0.72-1.47) on HCC incidence in this study.

CONCLUSION

Age, sex, hypertension and diabetes are risk factors for HCC in NAFLD patients. Diabetic NAFLD patients have a 2.27-fold increased risk of HCC, and health education and intervention for elderly, male, NAFLD patients with diabetes and hypertension need to be strengthened to promote a reduction in the risk of HCC.

Non-invasive biomarkers prognostic of decompensation events in NASH cirrhosis: a systematic literature review

Liver cirrhosis due to nonalcoholic steatohepatitis (NASH) is a life-threatening condition with increasing incidence world-wide. Although its symptoms are unspecific, it can lead to decompensation events such as ascites, hepatic encephalopathy, variceal hemorrhage, and hepatocellular carcinoma (HCC). In addition, an increased risk for cardiovascular events has been demonstrated in patients with NASH. Pharmacological treatments for NASH cirrhosis are not yet available, one of the reasons being the lack in surrogate endpoints available in clinical trials of NASH cirrhosis. The feasibility of non-invasive prognostic biomarkers makes them interesting candidates as possible surrogate endpoints if their change following treatment would result in better outcomes for patients in future clinical trials of NASH cirrhosis. In this systematic literature review, a summary of the available literature on the prognostic performance of non-invasive biomarkers in terms of cardiovascular events, liver-related events, and mortality is outlined. Due to the scarcity of data specific for NASH cirrhosis, this review includes studies on NAFLD whose evaluation focuses on cirrhosis. Our search strategy identified the following non-invasive biomarkers with prognostic value in studies of NASH patients: NAFLD fibrosis score (NFS), Fibrosis-4 (FIB-4), aspartate aminotransferase (AST) to platelet ratio index (APRI), enhanced liver fibrosis (ELF™), BARD (BMI, AST/ALT (alanine aminotransferase) ratio, diabetes), Hepamet Fibrosis Score (HFS), liver enzymes (AST + ALT), alpha-fetoprotein, platelet count, neutrophil to lymphocyte ratio (NLR), Lysyl oxidase-like (LOXL) 2, miR-122, liver stiffness, MEFIB (liver stiffness measured with magnetic resonance elastography (MRE) + FIB-4), and PNPLA3 GG genotype. The aim of the present systematic literature review is to provide the reader with a summary of the non-invasive biomarkers with prognostic value in NASH cirrhosis and give an evaluation of their utility as treatment monitoring biomarkers in future clinical trials.

Hepatocellular and extrahepatic cancer risk in people with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Much of the recognised health-care burden occurs in the minority of people with NAFLD who progress towards cirrhosis and require specialist follow-up, including risk stratification and hepatocellular carcinoma surveillance. NAFLD is projected to become the leading global cause of cirrhosis and hepatocellular carcinoma, but the frequency of non-cirrhotic hepatocellular carcinoma provides a challenge to existing surveillance strategies. Deaths from extrahepatic cancers far exceed those from hepatocellular carcinoma in NAFLD. Unlike hepatocellular carcinoma, the increased extrahepatic cancer risk in NAFLD is not dependent on liver fibrosis stage. Given that almost 30% of the world's adult population has NAFLD, extrahepatic cancer could represent a substantial health and economic issue. In this Review, we discuss current knowledge and controversies regarding hepatocellular carcinoma risk stratification and surveillance practices in people with NAFLD. We also assess the associations of extrahepatic cancers with NAFLD and their relevance both in the clinic and the wider community.

MASLD and the Development of HCC: Pathogenesis and Therapeutic Challenges

Metabolic-dysfunction-associated steatotic liver disease (MASLD, previously known as non-alcoholic fatty liver disease (NAFLD)) represents a rapidly increasing cause of chronic liver disease and hepatocellular carcinoma (HCC), mirroring increasing rates of obesity and metabolic syndrome in the Western world. MASLD-HCC can develop at an earlier stage of fibrosis compared to other causes of chronic liver disease, presenting challenges in how to risk-stratify patients to set up effective screening programmes. Therapeutic decision making for MASLD-HCC is also complicated by medical comorbidities and disease presentation at a later stage. The response to treatment, particularly immune checkpoint inhibitors, may vary by the aetiology of the disease, and, in the future, patient stratification will be key to optimizing the therapeutic pathways.

The greater impact of PNPLA3 polymorphism on liver-related events in Japanese non-alcoholic fatty liver disease patients: A multicentre cohort study

BACKGROUND & AIMS

PNPLA3 rs738409 has been associated with an increased risk of liver-related events in patients with non-alcoholic fatty liver disease (NAFLD). In this study, we investigated the epidemiology of NAFLD and the impact of PNPLA3 on prognosis in Japan.

METHODS

A longitudinal multicentre cohort study, the JAGUAR study, includes 1550 patients with biopsy-proven NAFLD in Japan. We performed genetic testing and evaluated outcomes from this cohort. Liver-related events were defined as hepatocellular carcinoma (HCC) and decompensated liver cirrhosis events.

RESULTS

During follow-up (median [range], 7.1 [1.0-24.0] years), 80 patients developed HCC, 104 developed liver-related events, and 59 died of any cause. The 5-year rate of liver-related events for each single-nucleotide polymorphism was 0.5% for CC, 3.8% for CG, and 5.8% for GG. Liver-related deaths were the most common (n = 28); only three deaths were due to cardiovascular disease. Multivariate analysis identified carriage of PNPLA3 CG/GG (hazard ratio [HR] 16.04, p = .006) and FIB-4 index >2.67 (HR 10.70, p < .01) as predictors of liver-related event development. No HCC or liver-related death was found among patients with PNPLA3 CC. There was a significantly increased risk of HCC, liver-related events, and mortality for CG/GG versus CC, but no difference between the CG and GG genotypes.

CONCLUSIONS

In Japanese individuals, the main cause of death from NAFLD is liver-related death. The greater risk of liver-related events incurred by PNPLA3 G allele was shown in Japan. Risk stratification for NAFLD in Japan is best accomplished by integrating PNPLA3 with the FIB-4 index.

Nonalcoholic fatty liver disease and hepatocellular carcinoma:Insights in epidemiology, pathogenesis, imaging, prevention and therapy

Hepatocellular carcinoma (HCC) is estimated to be the third leading cause of cancer-related mortality and is characterized by low survival rates. Nonalcoholic fatty liver disease (NAFLD) is emerging as a leading cause of HCC, whose rates are increasing, owing to the increasing prevalence of NAFLD. The pathogenesis of NAFLD-associated HCC is multifactorial: insulin resistance, obesity, diabetes and the low-grade hepatic inflammation, which characterizes NAFLD, seem to play key roles in the development and progression of HCC. The diagnosis of NAFLD-associated HCC is based on imaging in the presence of liver cirrhosis, preferably computerized tomography or magnetic resonance imaging, but liver biopsy for histological confirmation is usually required in the absence of liver cirrhosis. Some preventive measures have been recommended for NAFLD-associated HCC, including weight loss, cessation of even moderate alcohol drinking and smoking, as well as the use of metformin, statins and aspirin. However, these preventive measures are mainly based on observational studies, thus they need validation in trials of different design before introducing in clinical practice. The treatment of NAFLD should be tailored on an individual basis and should be ideally determined by a multidisciplinary team. In the last two decades, new medications, including tyrosine kinase inhibitors and immune checkpoints inhibitors, have improved the survival of patients with advanced HCC, but trials specifically designed for patients with NAFLD-associated HCC are scarce. The aim of this review was to overview evidence on the epidemiology and pathophysiology of NAFLD-associated HCC, then to comment on imaging tools for its appropriate screening and diagnosis, and finally to critically summarize the currently available options for its prevention and treatment.

Genetics of Hepatocellular Carcinoma: From Tumor to Circulating DNA

Hepatocellular carcinoma (HCC) accounts for 90% of primary hepatic malignancies and is one of the major causes of cancer-related death. Over the last 15 years, the molecular landscape of HCC has been deciphered, with the identification of the main driver genes of liver carcinogenesis that belong to six major biological pathways, such as telomere maintenance, Wnt/b-catenin, P53/cell cycle regulation, oxidative stress, epigenetic modifiers, AKT/mTOR and MAP kinase. The combination of genetic and transcriptomic data composed various HCC subclasses strongly related to risk factors, pathological features and prognosis. However, translation into clinical practice is not achieved, mainly because the most frequently mutated genes are undruggable. Moreover, the results derived from the analysis of a single tissue sample may not adequately catch the intra- and intertumor heterogeneity. The analysis of circulating tumor DNA (ctDNA) is broadly developed in other types of cancer for early diagnosis, prognosis and monitoring under systemic treatment in order to identify primary and secondary mechanisms of resistance. The aim of this review is to describe recent data about the HCC molecular landscape and to discuss how ctDNA could be used in the future for HCC detection and management.

Immunometabolic factors contributing to obesity-linked hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major public health concern that is promoted by obesity and associated liver complications. Onset and progression of HCC in obesity is a multifactorial process involving complex interactions between the metabolic and immune system, in which chronic liver damage resulting from metabolic and inflammatory insults trigger carcinogenesis-promoting gene mutations and tumor metabolism. Moreover, cell growth and proliferation of the cancerous cell, after initiation, requires interactions between various immunological and metabolic pathways that provide stress defense of the cancer cell as well as strategic cell death escape mechanisms. The heterogenic nature of HCC in addition to the various metabolic risk factors underlying HCC development have led researchers to focus on examining metabolic pathways that may contribute to HCC development. In obesity-linked HCC, oncogene-induced modifications and metabolic pathways have been identified to support anabolic demands of the growing HCC cells and combat the concomitant cell stress, coinciding with altered utilization of signaling pathways and metabolic fuels involved in glucose metabolism, macromolecule synthesis, stress defense, and redox homeostasis. In this review, we discuss metabolic insults that can underlie the transition from steatosis to steatohepatitis and from steatohepatitis to HCC as well as aberrantly regulated immunometabolic pathways that enable cancer cells to survive and proliferate in the tumor microenvironment. We also discuss therapeutic modalities targeted at HCC prevention and regression. A full understanding of HCC-associated immunometabolic changes in obesity may contribute to clinical treatments that effectively target cancer metabolism.

NAFLD-related hepatocellular carcinoma: The growing challenge

Hepatocellular carcinoma (HCC) is a common cause of cancer-related mortality and morbidity worldwide. With the obesity pandemic, NAFLD-related HCC is contributing to the burden of disease exponentially. Genetic predisposition and clinical risk factors for NAFLD-related HCC have been identified. Cirrhosis is a well-known and major risk factor for NAFLD-related HCC. However, the occurrence of NAFLD-related HCC in patients without cirrhosis is increasingly recognized and poses a significant challenge regarding cancer surveillance. It is of paramount importance to develop optimal risk stratification scores and models to identify subsets of the population at high risk so they can be enrolled in surveillance programs. In this review, we will discuss the risks and prediction models for NAFLD-related HCC.

The Implications of Noncoding RNAs in the Evolution and Progression of Nonalcoholic Fatty Liver Disease (NAFLD)-Related HCC

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver pathology worldwide. Meanwhile, liver cancer represents the sixth most common malignancy, with hepatocellular carcinoma (HCC) as the primary, most prevalent subtype. Due to the rising incidence of metabolic disorders, NAFLD has become one of the main contributing factors to HCC development. However, although NAFLD might account for about a fourth of HCC cases, there is currently a significant gap in HCC surveillance protocols regarding noncirrhotic NAFLD patients, so the majority of NAFLD-related HCC cases were diagnosed in late stages when survival chances are minimal. However, in the past decade, the focus in cancer genomics has shifted towards the noncoding part of the genome, especially on the microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), which have proved to be involved in the regulation of several malignant processes. This review aims to summarize the current knowledge regarding some of the main dysregulated, noncoding RNAs (ncRNAs) and their implications for NAFLD and HCC development. A central focus of the review is on miRNA and lncRNAs that can influence the progression of NAFLD towards HCC and how they can be used as potential screening tools and future therapeutic targets.

The impact of polymorphism in PNPLA3 and TM6SF2 genes on the susceptibility and survival of hepatitis C-related hepatocellular carcinoma

Background

Genetic variants of Patatin-like phospholipase domain-containing protein 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) genes have been reported with the development of hepatocellular carcinoma (HCC). This study aims to explore the role of The PNPLA3 rs738409 and TM6SF2 rs58542926 single-nucleotide polymorphisms (SNPs) on the incidence and survival of HCV-induced HCC in Egyptians.

Methods and results

This case-control study included (120) HCC and (144) hepatitis C virus (HCV) patients. Baseline clinical, laboratory, tumor characteristics data, HCC recurrence, and overall survival were collected. PNPLA3 rs738409 and TM6SF2 rs58542926 polymorphism were detected by TaqMan allelic discrimination assay. We found that HCC patients were significantly older with male predominance. A significant difference between the TT genotypes of TM6SF2 frequency was observed in HCC compared with HCV patients. Moreover, the T allele of TM6SF2 distributions revealed a significant contribution to the different stages of HCC (p=0.03). Both PNPLA3 rs738409 and TM6SF2 rs58542926 variants showed a significant relation with treatment response according to the modified RECIST criteria. Age and diabetes mellitus were the independent factors associated with the development of HCC by multivariate regression analysis.

Conclusions

TM6SF2 rs58542926 polymorphism, not PNPLA3 rs738409, could be implicated in the development of HCV-induced HCC and its progression.

Comparison of long‐term prognosis between non‐obese and obese patients with non‐alcoholic fatty liver disease

Background and Aim

Non‐alcoholic fatty liver disease (NAFLD) can progress in non‐obese patients as in obese patients. Reports on long‐term prognosis in non‐obese NAFLD patients are controversial. Therefore, we aimed to examine the long‐term prognosis of non‐obese patients with NAFLD.

Methods

This single‐center, retrospective cohort study enrolled biopsy‐proven non‐obese and obese NAFLD patients between January 2002 and December 2011 and followed them up until 31 March 2021, for death and clinical events (cardiovascular and liver‐related events and extrahepatic cancers).

Results

Of the 223 NAFLD patients, 58 (26.0%) were non‐obese. Compared with obese patients, they had a lower fibrosis stage (0.8 ± 0.80 vs 1.2 ± 0.91; P = 0.004), milder lobular inflammation (0.9 ± 0.7 vs 1.1 ± 0.7; P = 0.02), and significantly lower serum creatinine, total bilirubin, ferritin, and type IV collagen 7S and higher high‐density lipoprotein levels. After a median follow‐up of 8.9 years, no significant difference was noted in mortality between the two groups (2 [3.4%] non‐obese vs 5 [3.0%] obese; log‐rank test, P = 0.63). Twelve patients (20.7%) in the non‐obese group and 32 (19.4%) in the obese group had clinical events. Although the obese group had a higher incidence of clinical events during the first 10 years of follow‐up, the non‐obese group had a higher incidence after that (log‐rank test, P = 0.67). The non‐obese group had a high incidence of malignancy (9 [15.5%] non‐obese vs 14 [8.3%] obese; P = 0.13).

Conclusion

Non‐obese NAFLD does not necessarily have a good prognosis, and some cases have a poor prognosis such as extrahepatic cancers. Further validation is required in the future.

Changing clinical management of NAFLD in Asia

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, affecting approximately 25% of the world's population. Recently, because of the sedentary lifestyle and overnutrition resulting from urbanisation, the burden of NAFLD has rapidly increased in many Asian countries. Currently, the prevalence of NAFLD in Asia is approximately 30%, as is the case in many Western countries. In Asia, the prevalence and presentation of NAFLD vary widely across regions because of the substantial diversity in race, socioeconomic status and living environment. Furthermore, the dual aetiology of fatty liver, particularly with viral hepatitis in Asia, makes it complex and challenging to manage. Because Asians are likely to have central adiposity and insulin resistance, approximately 7%-20% of non-obese Asians with body mass indexes of less than 25 kg/m² are estimated to have NAFLD. Accumulating evidence indicates that NAFLD is associated with various extrahepatic comorbidities such as cardiovascular disease, chronic kidney disease, malignancy, in addition to liver-specific complications. Therefore, NAFLD should be managed as a multisystem disease in conjunction with metabolic syndrome. Lifestyle modification remains the basis of NAFLD management, but few patients can achieve adequate weight loss and maintain it long term. While various pharmacological agents are in phase 3 trials for steatohepatitis, Asian patients are underrepresented in most trials. This article reviews the epidemiological trends, clinical features, optimal assessment and current management practices for NAFLD in Asia.

Risk factors and diagnostic biomarkers for nonalcoholic fatty liver disease-associated hepatocellular carcinoma: Current evidence and future perspectives

High rates of excessive calorie intake diets and sedentary lifestyles have led to a global increase in nonalcoholic fatty liver disease (NAFLD). As a result, this condition has recently become one of the leading causes of hepatocellular carcinoma (HCC). Furthermore, the incidence of NAFLD-associated HCC (NAFLD-HCC) is expected to increase in the near future. Advanced liver fibrosis is the most common risk factor for NAFLD-HCC. However, up to 50% of NAFLD-HCC cases develop without underlying liver cirrhosis. Epidemiological studies have revealed many other risk factors for this condition; including diabetes, other metabolic traits, obesity, old age, male sex, Hispanic ethnicity, mild alcohol intake, and elevated liver enzymes. Specific gene variants, such as single-nucleotide polymorphisms of patatin-like phospholipase domain 3, transmembrane 6 superfamily member 2, and membrane-bound O-acyl-transferase domain-containing 7, are also associated with an increased risk of HCC in patients with NAFLD. This clinical and genetic information should be interpreted together for accurate risk prediction. Alpha-fetoprotein (AFP) is the only biomarker currently recommended for HCC screening. However, it is not sufficiently sensitive in addressing this diagnostic challenge. The GALAD score can be calculated based on sex, age, lectin-bound AFP, AFP, and des-carboxyprothrombin and is reported to show better diagnostic performance for HCC. In addition, emerging studies on genetic and epigenetic biomarkers have also yielded promising diagnostic potential. However, further research is needed to establish an effective surveillance program for the early diagnosis of NAFLD-HCC.

MAFLD: Renovation of clinical practice and disease awareness of fatty liver

Recently, international expert panels have proposed a new definition of fatty liver: metabolic dysfunction-associated fatty liver disease (MAFLD). MAFLD is not just a simple renaming of non-alcoholic fatty liver disease (NAFLD). The unique feature of MAFLD is the inclusion of metabolic dysfunctions, which are high-risk factors for events. In addition, MAFLD is independent of alcohol intake and the co-existing causes of liver disease. This new concept of MAFLD may have a widespread impact on patients, medical doctors, medical staff, and various stakeholders regarding fatty liver. Thus, MAFLD may renovate clinical practice and disease awareness of fatty liver. In this review, we introduce the definition of and rationale for MAFLD. We further describe representative cases showing how the diagnostic processes differ between MAFLD and NAFLD. We also summarize recent studies comparing MAFLD with NAFLD and discuss the impact of MAFLD on clinical trials, Japanese populations, and disease awareness.

Incidence of Hepatocellular Carcinoma in Patients With Nonalcoholic Fatty Liver Disease: A Systematic Review, Meta-analysis, and Meta-regression

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) may be a risk factor for hepatocellular carcinoma (HCC), but the extent of this association still needs to be addressed. Pooled incidence rates of HCC across the disease spectrum of NAFLD have never been estimated by meta-analysis.

METHODS

In this systematic review, we searched Web of Science, Embase, PubMed, and the Cochrane Library from January 1, 1950 through July 30, 2020. We included studies reporting on HCC incidence in patients with NAFLD. The main outcomes were pooled HCC incidences in patients with NAFLD at distinct severity stages. Summary estimates were calculated with random-effects models. Sensitivity analyses and meta-regression analyses were carried out to address heterogeneity.

RESULTS

We included 18 studies involving 470,404 patients. In patients with NAFLD at a stage earlier than cirrhosis, the incidence rate of HCC was 0.03 per 100 person-years (95% confidence interval [CI], 0.01-0.07; I² = 98%). In patients with cirrhosis, the incidence rate was 3.78 per 100 person-years (95% CI, 2.47-5.78; I² = 93%). Patients with cirrhosis undergoing regular screening for HCC had an incidence rate of 4.62 per 100 person-years (95% CI, 2.77-7.72; I² = 77%).

CONCLUSIONS

Patients with NAFLD-related cirrhosis have a risk of developing HCC similar to that reported for patients with cirrhosis from other etiologies. Evidence documenting the risk in patients with nonalcoholic steatohepatitis or simple steatosis is limited, but the incidence of HCC in these populations may lie below thresholds used to recommend a screening. Well-designed prospective studies in these subpopulations are needed. The protocol for this systematic review is registered in the Prospero database (registration number CRD42018092861).

The impact of single-nucleotide polymorphisms on liver stiffness and controlled attenuation parameter in patients treated with direct-acting antiviral drugs for hepatitis C infection

Single-nucleotide polymorphisms (SNPs) of patatin-like phospholipase domain-containing 3 (PNPLA3), tolloid-like protein 1 (TLL1) and interleukin-28 (IL28) have been identified as susceptibility factors for liver steatosis, inflammation and fibrosis in patients with hepatitis C virus (HCV) infection. Here, whether these polymorphisms affected predispositions to changes in liver stiffness (LS) and controlled attenuation parameter (CAP) following direct-acting antiviral (DAA) therapy was assessed. The changes in LS and steatosis in 77 HCV-infected patients receiving DAA therapy were compared with PNPLA3, TLL1 and IL28 genotypes, using CAP, FibroScan and Virtual Touch tissue quantification (VTTQ) before treatment and 12 weeks after the end of the treatment. VTTQ results showed that LS significantly decreased in PNPLA3 CC (P=0.035), TLL1 AA (P=0.011) and IL28B TT (P=0.005) genotypes; no significant differences were observed in PNPLA3 CG/GG, TLL1 AT/TT and IL28B TG/GG. FibroScan results showed that LS significantly decreased in TLL1 AA (P=0.028) and IL28B TT (P=0.032), with no significant difference in PNPLA3 CC. No significant differences were observed in PNPLA3 CG/GG, TLL1 AT/TT and IL28B TG/GG groups. CAP was significantly increased in PNPLA3 CG/GG (P=0.039 and P<0.05) and IL28B TT (P=0.014); no significant difference was observed in PNPLA3 CC and all genotypes of TLL1 and IL28B TG/GG. Therefore, these results indicated that SNPs could predict changes in LS and steatosis after DAA therapy.

Clinical practice advice on lifestyle modification in the management of nonalcoholic fatty liver disease in Japan: an expert review

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver diseases worldwide, including in Japan. The Japanese Society of Gastroenterology (JSGE) and the Japanese Society of Hepatology (JSH) have established the Japanese NAFLD/NASH guidelines in 2014 and revised these guidelines in 2020. As described in these guidelines, weight reduction by diet and/or exercise therapy is important for the treatment of NAFLD patients. The I148M single nucleotide polymorphism (rs738409 C > G) of PNPLA3 (patatin-like phospholipase domain-containing 3 protein) is widely known to be associated with the occurrence and progression of NAFLD. In the Japanese, the ratio of PNPLA3 gene polymorphisms found is approximately 20%, which is higher than that found in Westerners. In addition, the ratio of lean NAFLD patients is also higher in Japan than in Western countries. Therefore, the method for lifestyle guidance for the NAFLD patients in Japan would be different from that for the people in Western countries. The problems in the treatment of NAFLD patients include alcohol consumption and sarcopenia. Therefore, guidelines that can help clinicians treat Japanese patients with NAFLD are needed. In this expert review, we summarize evidence-based interventions for lifestyle modification (diet, exercise, alcohol, and sarcopenia) for the treatment of patients with NAFLD, especially from Japan and Asian countries.

PNPLA3 genotype and fibrosis-4 index predict cardiovascular diseases of Japanese patients with histopathologically-confirmed NAFLD

Background

Reliable noninvasive predictors of the top three causes of death [cardiovascular diseases (CVDs), malignancies, and liver-related events in patients with non-alcoholic fatty liver disease (NAFLD)] have not yet been determined.

Methods

We retrospectively investigated the incidence of three complications [CVDs, malignancy (except for liver cancer), and liver-related events] in 477 Japanese patients with histo-pathologically confirmed NAFLD for a median follow-up of 5.9 years. In addition to histological findings, we also investigated noninvasive predictors.

Results

A score of ≥ 2.67 for the noninvasive diagnosis of stage 4 fibrosis based on the Fibrosis-4 (FIB-4) index indicated a high level area under the receiver operating characteristic (AUROC) curve (0.90), sensitivity (82.9%), specificity (86.4%), and negative predictive value [(NPV) of 98.5%]. The yearly incidence rates of CVDs, malignancies, and liver-related events were found to be 1.04%, 0.83%, and 0.30%, respectively. Multivariate analysis identified a FIB-4 index ≥ 2.67 score as a significant and independent, noninvasive predictor of these three complications. Furthermore, the cumulative incidence rates of CVDs were significantly different among the three genotypes of PNPLA3. PNPLA3 genotype CC, chronic kidney disease (CKD), and FIB-4 index ≥ 2.67 was could be attributed to these three significant CVD risk factors. The rates of CVDs were significantly different among the three subgroups based on the combination of risk factors. In malignancy (except for liver cancer), the incidence rate of colon cancer was 25.0%; in particular, the rate in females was 53.8%.

Conclusions

Our results highlighted the importance of the PNPLA3 genotype and FIB-4 index ≥ 2.67 on the incidence of complications in Japanese patients with NAFLD, especially the incidence of CVDs. Early diagnosis, based on the presence of one or more risk factors, and early treatment might improve the prognosis for NAFLD patients.

Outcomes of Japanese patients with non-alcoholic fatty liver disease according to genetic background and lifestyle-related diseases

INTRODUCTION AND OBJECTIVES

Genetic background may be involved in the mechanisms of liver injury and the development of non-alcoholic fatty liver disease (NAFLD). However, its contributions to the long-term outcome of NAFLD have been unclear.

METHODS

We enrolled 314 Japanese patients with biopsy-confirmed NAFLD from 2000 to 2018 (161 men [51.3%]; median age, 53 [14-84] years; 114 with advanced fibrosis [37.5%]) in the patients without hepatocellular carcinoma at diagnosis. Genomic DNA was extracted from peripheral blood and single nucleotide polymorphisms (SNPs) were analyzed. Associations of mortality with patatin-like phospholipase 3 (PNPLA3) and aldehyde dehydrogenase 2 (ALDH2) were analyzed. Finally, a subgroup analysis according to lifestyle-related disease was performed.

RESULTS

During the median 7 years of follow-up, 20 patients (6.4%) died (13 liver-related [4.1%] and 7 non-liver-related deaths [2.2%]). Patients with ALDH2 (non-GG genotype) who had reduced alcohol metabolism tended to have a poor prognosis (p = 0.06). Patients carrying both risk SNPs of PNPLA3 (GG) and ALDH2 (non-GG) had a significantly poor prognosis (p = 0.01). In the subgroup analysis, patients with PNPLA3 (GG) who were non-diabetics (p = 0.06) or non-dyslipidemic (p = 0.03), with ALDH2 (non-GG) who were non-dyslipidemic (p = 0.01) or hypertensive (p = 0.03), also had a poor prognosis. The Cox analysis revealed that ALDH2 (non-GG) was associated with a poor prognosis (Hazard ratio: 4.568, 95% Confidence Interval: 1.294-16.131, p = 0.02) similar to the liver function tests.

CONCLUSIONS

Genetic background may affect NAFLD prognosis and ALDH2 SNP could predict the outcome.

Evidence-based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis 2020

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health issue not only in Western countries but also in Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease that often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma (HCC). While a definite diagnosis of NASH requires liver biopsy to confirm the presence of hepatocyte ballooning, hepatic fibrosis is the most important prognostic factor in NAFLD. With so many NAFLD patients, it is essential to have an effective screening method for NAFLD with hepatic fibrosis. As HCC with non-viral liver disease has increased markedly in Japan, effective screening and surveillance of HCC are also urgently needed. The most common death etiology in NAFLD patients is cardiovascular disease event. Gastroenterologists must, therefore, pay close attention to CVD when examining NAFLD patients. In the updated guidelines, we propose screening and follow-up methods for hepatic fibrosis, HCC, and CVD in NAFLD patients. Several drug trials are ongoing for NAFLD/NASH therapy, however, there is currently no specific drug therapy for NAFLD/NASH. In addition to vitamin E and thiazolidinedione derivatives, recent trials have focused on sodium glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) analogues, and effective therapies are expected to be developed. These practical guidelines for NAFLD/NASH were established by the Japanese Society of Gastroenterology in conjunction with the Japan Society of Hepatology. Clinical evidence reported internationally between 1983 and October 2018 was collected, and each clinical and background question was evaluated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. This English summary pro- vides the core essentials of these clinical practice guidelines, which include the definition and concept, screening systems for hepatic fibrosis, HCC and CVD, and current therapies for NAFLD/NASH in Japan.

Liver Stiffness-Based Risk Prediction Model for Hepatocellular Carcinoma in Patients with Nonalcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased hepatocellular carcinoma (HCC) risk. We established and validated a liver stiffness (LS)-based risk prediction model for HCC development in patients with NAFLD. A total of 2666 and 467 patients with NAFLD were recruited in the training and validation cohorts, respectively. NAFLD was defined as controlled attenuated parameter ≥238 dB/m by transient elastography. Over a median of 64.6 months, HCC developed in 22 (0.8%) subjects in the training cohort. Subjects who developed HCC were older and had higher prevalence of diabetes and cirrhosis, lower platelet count, and higher AST levels compared to those who did not develop HCC (all p < 0.05). In multivariate analysis, age ≥60 years (hazard ratio (HR) = 9.1), platelet count <150 × 10³/μL (HR = 3.7), and LS ≥9.3 kPa (HR = 13.8) were independent predictors (all p < 0.05) that were used to develop a risk prediction model for HCC development, together with AST ≥34 IU/L. AUCs for predicting HCC development at 2, 3, and 5 years were 0.948, 0.947, and 0.939, respectively. This model was validated in the validation cohort (AUC 0.777, 0.781, and 0.784 at 2, 3, and 5 years, respectively). The new risk prediction model for NAFLD-related HCC development showed acceptable performance in the training and validation cohorts.

Combination of type IV collagen 7S, albumin concentrations, and platelet count predicts prognosis of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and affects approximately 25% of the general global adult population. The prognosis of NAFLD patients with advanced liver fibrosis is known to be poor. It is difficult to assess disease progression in all patients with NAFLD; thus, it is necessary to identify patients who will show poor prognosis.

AIM

To investigate the efficacy of non-invasive biomarkers for predicting disease progression in patients with NAFLD.

METHODS

We investigated biomarkers associated with mortality in patients with NAFLD who visited the Kawasaki Medical School General Medical Center from 1996 to 2018 and underwent liver biopsy and had been followed-up for > 1 year. Cumulative overall mortality and liver-related events during follow-up were calculated using the Kaplan-Meier analysis and compared using log-rank testing. We calculated the odds ratio and performed receiver operating characteristic curve analysis with logistic regression analysis to determine the optimal cut-off value with the highest prognostic ability.

RESULTS

We enrolled 489 patients who were followed-up for a period of 1-22.2 years. In total, 13 patients died (2.7% of total patients enrolled); 7 patients died due to liver-related causes. Poor prognosis was associated with liver fibrosis on histological examination but not with inflammation or steatosis. Blood biomarkers associated with mortality were platelet counts, albumin levels, and type IV collagen 7S levels. The optimal cutoff index for predicting total mortality was a platelet count of 15 × 10⁴/μL, albumin level of 3.5 g/dL, and type IV collagen 7S level of 5 mg/dL. In particular, only one-factor patients with NAFLD presenting with platelet counts ≤ 15 × 10⁴/μL, albumin levels ≤ 3.5 g/dL, or type IV collagen 7S ≥ 5 mg/dL showed 5-year, 10-year, and 15-year survival rates of 99.7%, 98.3%, and 94%, respectively. However, patients with two factors had lower 5-year and 10-year survival rates of 98% and 43%, respectively. Similarly, patients with all three factors showed the lowest 5-year and 10-year survival rates of 53% and 26%, respectively.

CONCLUSION

A combination of the three non-invasive biomarkers is a useful predictor of NAFLD prognosis and can help identify patients with NAFLD who are at a high risk of all-cause mortality.

Progression from Nonalcoholic Fatty Liver to Nonalcoholic Steatohepatitis Cirrhosis Confirmed by Liver Histology after 14 Years

A 44-year-old patient progressed from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) cirrhosis. She was diagnosed with NAFL via a liver biopsy. At 56 years old, she was diagnosed with NASH stage 3 via a second liver biopsy. One year later, she was diagnosed with NASH cirrhosis via a third liver biopsy. This is the first study to report the gradual deterioration of liver histology shown via three liver biopsies and fibrosis markers in a patient who progressed from NAFL to NASH cirrhosis. Following menopause, it is necessary to be aware of the rapid development of liver fibrosis.

The Effect of Genetic Polymorphism in Response to Body Weight Reduction in Japanese Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

weight loss as a result of lifestyle intervention is effective when treating non-alcoholic fatty liver disease (NAFLD). We estimated the effects of PNPLA3 rs738409 and HSD17B13 rs6834314 variants in response to diet therapy in Japanese patients with NAFLD.

METHODS

we analyzed the correlation between the change in liver stiffness and change in body weight in 140 patients administered diet therapy for 1-year, according to PNPLA3 and HSD17B13 genotypes.

RESULTS

the bodyweight (BW) reduction rate was greater in patients with the PNPLA3 genotype CC than CG and GG (p = 0.035). Change in liver stiffness measurement (LSM) was significantly associated with a change in BW in PNPLA3 CG/GG (r = 0.279/0.381), but not in PNPLA3 CC (p = 0.187). Change in LSM was correlated with change in BW only in patients with HSD17B13 AG/GG (r = 0.425), but not the AA genotype (p = 0.069). A multivariate analysis identified that a change in LSM was correlated with a change in BW in carriers of HSD17B13 AG/GG (B = 3.043, p = 0.032), but not HSD17B13 AA. The change in LSM of patients with a BW reduction of more than 7% (0.50) was significantly greater than that of patients with a BW reduction of less than 7% (0.83) (p = 0.038).

CONCLUSIONS

in Japanese patients with NAFLD, HSD17B13 rs6834314 polymorphism is associated with the change in LSM by lifestyle intervention. The approach, including genetic assessments, may contribute to the establishment of appropriate therapeutic strategies to treat NAFLD.

NAFLD-Associated HCC: Progress and Opportunities

Due to an increase in the obesity-associated metabolic syndrome of epidemic proportions, nonalcoholic fatty liver disease (NAFLD) is becoming a leading cause of hepatocellular carcinoma (HCC) in western countries. This presents added challenges, as NAFLD-associated HCC tends to present at an advanced stage in older patients with co-morbidities. Their prognosis is generally poor with the benefits of standard therapies less certain. The pathogenesis of NAFLD-associated HCC is multifactorial and not well understood, although the risk of HCC developing undoubtedly increases as NAFLD progresses to steatohepatitis and cirrhosis. Recent advances in our understanding of the drivers of NAFLD and HCC will hopefully lead to the development of clinically relevant biomarkers, tools and strategies to aid the identification of high-risk patients, inform preventive measures, and introduction of better tolerated targeted therapies. Lifestyle modification and chemoprevention with drugs such as anti-platelets, statins and anti-diabetics are being evaluated for HCC prevention. The landmark IMBrave150 study introducing the combination of atezolizumab and bevacizumab has recently transformed the landscape of systemic therapies in HCC, with follow-up analyses and real-world data for patients with NAFLD-associated HCC eagerly anticipated. While responses may vary in ways not yet appreciated, the rate of discovery and progress suggests imminent change and opportunities.

Global epidemiology of NAFLD-related HCC: trends, predictions, risk factors and prevention

One quarter of the global population is estimated to have nonalcoholic fatty liver disease (NAFLD). The incidence of nonalcoholic steatohepatitis (NASH) is projected to increase by up to 56% in the next 10 years. NAFLD is already the fastest growing cause of hepatocellular carcinoma (HCC) in the USA, France and the UK. Globally, the prevalence of NAFLD-related HCC is likely to increase concomitantly with the growing obesity epidemic. The estimated annual incidence of HCC ranges from 0.5% to 2.6% among patients with NASH cirrhosis. The incidence of HCC among patients with non-cirrhotic NAFLD is lower, approximately 0.1 to 1.3 per 1,000 patient-years. Although the incidence of NAFLD-related HCC is lower than that of HCC of other aetiologies such as hepatitis C, more people have NAFLD than other liver diseases. Urgent measures that increase global awareness and tackle the metabolic risk factors are necessary to reduce the impending burden of NAFLD-related HCC. Emerging evidence indicates that reduced immune surveillance, increased gut inflammation and gut dysbiosis are potential key steps in tumorigenesis. In this Review, we discuss the global epidemiology, projections and risk factors for NAFLD-related HCC, and propose preventive strategies to tackle this growing problem.

The Current View of Nonalcoholic Fatty Liver Disease-Related Hepatocellular Carcinoma

Simple Summary

The incidence of nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) is increasing. However, an effective screening or surveillance method is not established. Recently, the NAFLD/nonalcoholic steatohepatitis (NASH) guidelines of Japan were revised to incorporate new strategies and evidence for the management and surveillance of NAFLD/NASH. Advanced fibrosis and lifestyle-related and metabolic comorbidities, especially obesity and diabetes mellitus, are associated with HCC development. At the first screening, serum markers of hepatic fibrosis (hyaluronic acid, type IV collagen 7S, and mac-2 binding protein), or the fibrosis (FIB)-4 index or the nonalcoholic fatty liver disease fibrosis score (NFS), or a platelet count should be evaluated. When liver fibrosis is indicated, consultation with a gastroenterology specialist should be considered for the second screening. The risk of HCC should be stratified using the FIB-4 index or the NFS. Liver stiffness should be measured using vibration-controlled transient elastography in those at intermediate or high risk. Blood tests and imaging should be performed every 6–12 months in patients with advanced fibrosis for HCC surveillance. We review here what is known about NAFLD-HCC and provide perspectives for future research.

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and can develop into hepatocellular carcinoma (HCC). The incidence of NAFLD-related HCC, which is accompanied by life-threatening complications, is increasing. Advanced fibrosis and lifestyle-related and metabolic comorbidities, especially obesity and diabetes mellitus, are associated with HCC development. However, HCC is also observed in the non-cirrhotic liver. Often, diagnosis is delayed until the tumor is relatively large and the disease is advanced; an effective screening or surveillance method is urgently required. Recently, the NAFLD/nonalcoholic steatohepatitis (NASH) guidelines of Japan were revised to incorporate new strategies and evidence for the management and surveillance of NAFLD/NASH. Fibrosis must be tested for noninvasively, and the risk of carcinogenesis must be stratified. The treatment of lifestyle-related diseases is expected to reduce the incidence of NAFLD and prevent liver carcinogenesis.

Evidence-based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis 2020

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health issue not only in Western countries but also in Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease that often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma (HCC). While a definite diagnosis of NASH requires liver biopsy to confirm the presence of hepatocyte ballooning, hepatic fibrosis is the most important prognostic factor in NAFLD. With so many NAFLD patients, it is essential to have an effective screening method for NAFLD with hepatic fibrosis. As HCC with non-viral liver disease has increased markedly in Japan, effective screening and surveillance of HCC are also urgently needed. The most common death etiology in NAFLD patients is cardiovascular disease (CVD) event. Gastroenterologists must, therefore, pay close attention to CVD when examining NAFLD patients. In the updated guidelines, we propose screening and follow-up methods for hepatic fibrosis, HCC, and CVD in NAFLD patients. Several drug trials are ongoing for NAFLD/NASH therapy, however, there is currently no specific drug therapy for NAFLD/NASH. In addition to vitamin E and thiazolidinedione derivatives, recent trials have focused on sodium glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) analogues, and effective therapies are expected to be developed. These practical guidelines for NAFLD/NASH were established by the Japanese Society of Gastroenterology in conjunction with the Japan Society of Hepatology. Clinical evidence reported internationally between 1983 and October 2018 was collected, and each clinical and background question was evaluated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. This English summary provides the core essentials of these clinical practice guidelines, which include the definition and concept, screening systems for hepatic fibrosis, HCC and CVD, and current therapies for NAFLD/NASH in Japan.

Hepatocellular carcinoma and other complications of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in Japan: A structured review of published works

AIMS

Hepatocellular carcinoma (HCC) is a significant cause of morbidity and mortality in Japan. As the treatment of viral hepatitis improves, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are rapidly becoming leading causes of HCC in Japan. This structured review aims to characterize the morbidity and mortality of HCC and other malignant and non-malignant complications among Japanese NAFLD and NASH patients.

METHODS

An English and Japanese structured search of published works was undertaken in PubMed, Embase, and Ichushi Web databases, identifying 6553 studies, 34 of which met predefined inclusion criteria.

RESULTS

Hepatocellular carcinoma was the most common incident malignancy among NAFLD/NASH patients, with higher incidence in patients with advanced/severe fibrosis (F3/F4) of 10.5%-20.0%. Although NASH results in a lower HCC cumulative incidence than hepatitis C virus (HCV) (11.3% vs. 30.5%), they have similar impacts on health outcomes, including overall mortality. Among Japanese NASH patients, HCC was found to be the main driver of mortality (40.0% in 2.7 years in NASH-HCC). With longer follow-up, higher mortality rates are observed in F3/4 patients: 25.0% in NASH F3/F4 versus 0.0% in NASH F0/2 over 7.7 years. The NASH-HCC patients also have a higher post-operative mortality than HCV-HCC patients. Additionally, NAFLD/NASH patients had higher rates of cardiovascular disease than non-NAFLD/NASH controls, and slightly higher rates of gastric cancer than HCV patients.

CONCLUSION

Hepatocellular carcinoma is the most common malignancy and cause of death among NAFLD/NASH patients in Japan, with higher mortality observed among those with advanced disease and complications. Early identification and effective treatments are needed.

Surveillance of Hepatocellular Carcinoma in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is becoming the leading cause of hepatocellular carcinoma (HCC), liver-related mortality, and liver transplantation. There is sufficient epidemiological cohort data to recommend the surveillance of patients with NAFLD based upon the incidence of HCC. The American Gastroenterology Association (AGA) expert review published in 2020 recommends that NAFLD patients with cirrhosis or advanced fibrosis estimated by non-invasive tests (NITs) consider HCC surveillance. NITs include the fibrosis-4 (FIB-4) index, the enhanced liver fibrosis (ELF) test, FibroScan, and MR elastography. The recommended surveillance modality is abdominal ultrasound (US), which is cost effective and noninvasive with good sensitivity. However, US is limited in obese patients and those with NAFLD. In NAFLD patients with a high likelihood of having an inadequate US, or if an US is attempted but inadequate, CT or MRI may be utilized. The GALAD score, consisting of age, gender, AFP, the lens culinaris-agglutinin-reactive fraction of AFP (AFP-L3), and the protein induced by the absence of vitamin K or antagonist-II (PIVKA-II), can help identify a high risk of HCC in NAFLD patients. Innovative parameters, including a Mac-2 binding protein glycated isomer, type IV collagen 7S, free apoptosis inhibitor of the macrophage, and a combination of single nucleoside polymorphisms, are expected to be established. Considering the large size of the NAFLD population, optimal screening tests must meet several criteria, including high sensitivity, cost effectiveness, and availability.

Attenuated effect of PNPLA3 on hepatic fibrosis by HSD17B13 in Japanese patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

PNPLA3 rs738409 has been associated with increased risks of fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Recently, carriage of the rs6834314 G allele, which is in high linkage with rs72613567 of 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13), was reported to be associated with a reduced risk of liver injury in NAFLD patients. We estimated the impact of these genetic variants on hepatic fibrosis in Japanese patients with NAFLD.

METHODS

We analysed the associations of these genetic variants with liver histology in 290 Japanese patients with biopsy-proven NAFLD diagnosed during 2002-2019. During follow-up, 14 patients (4.8%) developed hepatocellular carcinoma.

RESULTS

Prevalences of the PNPLA3 rs738409 genotypes were 0.17 for CC, 0.41 for CG, 0.42 for GG, and those for HSD17B13 rs6834314 were 0.54 for AA, 0.39 for AG and 0.07 for GG. There was no significant interaction between the PNPLA3 and HSD17B13 genotypes. Prevalences of advanced fibrosis according to PNPLA3/HSD17B13 genotypes were 0.16 for CC,CG/AG,GG, 0.20 for CC,CG/AA, 0.30 for GG/AG,GG and 0.37 for GG/AA. Multivariate analysis identified PNPLA3 GG as a predictor of advanced fibrosis (stage 3/4) in carriers of HSD17B13 AA (odds ratio 2.4, P = .041), but not HSD17B13 AG/GG (P = .776). The HSD17B13 genotype G was significantly associated with lower prevalences of severe inflammation and ballooning and tended to be associated with a higher prevalence of advanced steatosis.

CONCLUSIONS

In Japanese patients with NAFLD, carriage of the HSD17B13 rs6834314 G allele attenuated the effect of the PNPLA3 rs738409 GG genotype on advanced hepatic fibrosis.

Epidemiology: Pathogenesis, and Diagnostic Strategy of Diabetic Liver Disease in Japan

Type 2 diabetes (T2D) is closely associated with nonalcoholic fatty liver disease (NAFLD). Nonalcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to cirrhosis, hepatocellular carcinoma (HCC), and hepatic decompensation. Patients with T2D have twice the risk of HCC incidence compared with those without T2D. Because the hepatic fibrosis grade is the main determinant of mortality in patients with NAFLD, identifying patients with advanced fibrosis using non-invasive tests (NITs) or imaging modalities is crucial. Globally, the fibrosis-4 index (FIB-4 index), NAFLD fibrosis score, and enhanced liver fibrosis test have been established to evaluate hepatic fibrosis. Two-step algorithms using FIB-4 index as first triaging tool are globally accepted. It remains unknown which kinds of NITs or elastography are best as the second step tool. In Japan, type IV collagen 7s or the CA-fibrosis index (comprising type IV collagen 7s and aspartate aminotransferase (AST)) is believed to precisely predict advanced fibrosis in NAFLD. Patients with NAFLD who have high non-invasive test results should be screened for HCC or esophageal varices. Risk factors of rapid fibrosis progression in NAFLD includes age, severe obesity, presence of T2D, menopause in women, and a patatin-like phospholipase domain containing the 3 GG genotype. Patients with NAFLD who have these risk factors should be intensively treated with lifestyle modification or pharmacotherapies for preventing liver-related mortality.

Epidemiology of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in Japan: A focused literature review

Non‐alcoholic fatty liver disease (NAFLD) and non‐alcoholic steatohepatitis (NASH) represent a growing unmet medical need and an increasingly prevalent cause of cirrhosis, hepatocellular carcinoma (HCC), and death in Japan. The aim of this review was to characterize the epidemiology of NAFLD and NASH in Japan. An English and Japanese literature search was conducted in PubMed, Embase, and ICHUSHI Web, identifying 6553 studies, 67 of which were included. Prevalence of NAFLD in the Japanese population rose from the early 1990s (12.6–12.9%) to the early 2000s (24.6–34.7% of the population). Japanese NASH prevalence is estimated to be 1.9–2.7%. NAFLD and NASH are more common among males than females; however, females experience more severe disease than males. While obese patients had higher prevalence of NAFLD/NASH, nonobese individuals (body mass index [BMI] <25 kg/m²) consistently comprised 20% to >35% of NAFLD and NASH patients. The evidence shows that, despite obesity being linked with worse disease stages, “lean‐NASH” also plays an important role in NASH epidemiology. Besides obesity, diabetes and metabolic syndrome appeared to be reliably associated with disease severity. The prevalence of advanced fibrosis or cirrhotic disease was the highest in patients with NASH‐HCC (44–80% with stage F3/F4 disease), while 21–50% of patients with NASH had F3/F4 disease. NAFLD/NASH is common in the Japanese population, and the prevalence of these conditions has tripled in the last two decades. Furthermore, these NAFLD/NASH patients have a high comorbidity burden. Early and efficient identification of safe and effective treatments for NAFLD/NASH patients is urgently needed.

Interplay of PNPLA3 and HSD17B13 Variants in Modulating the Risk of Hepatocellular Carcinoma among Hepatitis C Patients

A single-nucleotide polymorphism causing a C to G change in the PNPLA3 gene (rs738409) is associated with disease severity and development of hepatocellular carcinoma (HCC) in nonalcoholic fatty liver disease; the insertion variant rs72613567:TA of the 17β-hydroxysteroid dehydrogenase type 13 (HSD17B13) mitigates this detrimental effect. Our aim was to evaluate if the same holds true in chronic hepatitis C virus infection (HCV). With a case control retrospective study design, we selected 110 patients who developed HCC on a background of HCV infection, matching each patient for sex and age (±30 months) to three HCV-infected, non-HCC patients. All participants underwent genotyping for PNPLA3 and HSD17B13 gene variants. Both univariate and multivariate analyses of risk factors for advanced disease and HCC were performed. Carriage of PNPLA3 G∗ allele was associated with a trend of progressively more severe liver disease, from mild fibrosis to significant fibrosis, cirrhosis, and HCC (p = 0.007). When the HSD17B13:TA status of these patients was taken into account, the abovementioned trend was strengthened among HSD17B13 major allele homozygotes and completely blunted among carriers of the minor allele (p = 0.0003 and 0.953, respectively). In a conditional logistic regression model including diabetes and AST to platelet ratio index among predictor variables, the unfavourable genetic profile characterized by the coexistence of the PNPLA3 minor allele and HSD17B13 major allele (vs. all other possible combinations) was an independent risk factor for HCC (OR = 2.00, 95% CI: 1.23-3.26) together with a history of alcohol abuse. In conclusion, carriage of the combination PNPLA3 minor allele and HSD17B13 major allele may represent a risk factor for HCC among HCV-infected patients. The interplay between the two genes may explain some of the controversy on this topic and may be exploited to stratify HCC risk in hepatitis C.

PNPLA3 rs738409 is not associated with the risk of hepatocellular carcinoma and persistent infection of hepatitis B virus (HBV) in HBV-related subjects: A case-control study and meta-analysis on Asians

The association between rs738409 (C>G, I148M) with patatin-like phospholipase domain-containing 3 (PNPLA3) gene and the risk of hepatocellular carcinoma (HCC) was controversial in different ethnic populations. Our study aimed to explore the effect of PNPLA3 rs738409 on the risk of HCC and persistent infection of Hepatitis B virus (HBV) in a Chinese HBV-related population, and further evaluate its role in HCC risk among Asians. First, we performed a case-control study by recruiting 786 HBV-related HCC cases, 695 HBV persistent carriers and 719 HBV natural clearance subjects. PNPLA3 rs738409 was genotyped by MassARRAY platform. Second, we conducted a systematic review and meta-analysis on Asians to further validate our results. Our case-control study demonstrated that PNPLA3 rs738409 was not associated with HCC risk or persistent HBV infection (All P > 0.05). The subsequent meta-analysis included 13 Asian studies with 9,802 subjects. Results showed that PNPLA3 rs738409 might increase HCC risk among healthy subjects (pooled odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.11-1.95), but it had no influence on the development of HCC among HBV-related subjects (pooled OR = 1.07, 95%CI = 0.89-1.30). Our case-control study highlights that PNPLA3 rs738409 is probably not associated with the risk of HCC or persistent HBV infection in a Chinese HBV-related population. Besides, our systematic review and meta-analysis on Asians further suggest that PNPLA3 rs738409 may confer an increased risk of HCC among healthy people, but contribute little to the development of HCC among HBV-related subjects. Future studies are required to confirm these results.

Genetic Risk Factors and Disease Modifiers of Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease is strongly associated with obesity and the metabolic syndrome, but genetic factors also contribute to disease susceptibility. Human genetic studies have identified several common genetic variants contributing to nonalcoholic fatty liver disease initiation and progression. These findings have provided new insights into the pathogenesis of nonalcoholic fatty liver disease and opened up new avenues for the development of therapeutic interventions. In this review, we summarize the current state of knowledge about the genetic determinants of nonalcoholic fatty liver disease, focusing on the most robustly validated genetic risk factors and on recently discovered modifiers of disease progression.

Liver fat accumulation assessed by computed tomography is an independent risk factor for diabetes mellitus in a population-based study: SESSA (Shiga Epidemiological Study of Subclinical Atherosclerosis)

AIMS

Ectopic fat accumulation is related to insulin resistance and diabetes mellitus (DM). However, the effect of fatty liver on DM in non-obese individuals has not been clarified. We investigated whether liver fat accumulation assessed by computed tomography (CT) is associated with the incidence of DM.

METHODS

In a prospective population-based study, 640 Japanese men were followed up for 5 years. The liver to spleen (L/S) ratio of the CT attenuation value was used as the liver fat accumulation index. We calculated the odds ratio (OR) and 95% confidence interval (CI) for the DM incidence of per 1 standard deviation (SD) lower L/S and those of L/S < 1.0 compared with L/S ≥ 1.0, using logistic regression models.

RESULTS

Both per 1 SD lower L/S and L/S < 1.0 were significantly associated with a risk for DM incidence (1 SD lower L/S: OR = 1.57, 95%CI = 1.14-2.16; L/S < 1.0: OR = 2.27, 95%CI = 1.00-5.14). The relationship between L/S and incidence of DM was consistent in the obese and non-obese groups, with thresholds of BMI 25 kg/m², waist circumference 85 cm, or visceral adipose tissue 100 cm².

CONCLUSIONS

Liver fat accumulation assessed by CT was associated with the incidence of DM.

Factors influencing subclinical atherosclerosis in patients with biopsy-proven nonalcoholic fatty liver disease

Although the presence of nonalcoholic fatty liver disease (NAFLD) is known to be related to subclinical atherosclerosis, the relationship between the severity of NAFLD and subclinical atherosclerosis is not clear. This study aimed to clarify the factors related to subclinical arteriosclerosis, including the histopathological severity of the disease and PNPLA3 gene polymorphisms, in NAFLD patients. We measured brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness in 153 biopsy-proven NAFLD patients. The baPWV values were significantly higher in the advanced fibrosis group than in the less advanced group (median, 1679 cm/s vs 1489 cm/s; p = 5.49×10⁻⁴). Multiple logistic regression analysis revealed that older age (≥55 years) (p = 8.57×10⁻³; OR = 3.03), hypertension (p = 1.05×10⁻³; OR = 3.46), and advanced fibrosis (p = 9.22×10⁻³; OR = 2.94) were independently linked to baPWV ≥1600 cm/s. NAFLD patients were categorized into low-risk group (number of risk factors = 0), intermediate-risk group (= 1), and high-risk group (≥2) based on their risk factors, including older age, hypertension, and biopsy-confirmed advanced fibrosis. The prevalence of baPWV ≥1600 cm/s was 7.1% (3/42) in the low-risk group, 30.8% (12/39) in the intermediate-risk group, and 63.9% (46/72) in the high-risk group. Non-invasive liver fibrosis markers and scores, including the FIB-4 index, NAFLD fibrosis score, hyaluronic acid, Wisteria floribunda agglutinin positive Mac-2-binding protein, and type IV collagen 7s, were feasible substitutes for invasive liver biopsy. Older age, hypertension, and advanced fibrosis are independently related to arterial stiffness, and a combination of these three factors may predict risk of arteriosclerosis in NAFLD patients.

Antidiabetic Drugs and Statins in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease worldwide. Despite its high prevalence and rising incidence, there are currently no specific targeted pharmacotherapies approved by the Food and Drug Administration (FDA) for nonalcoholic steatohepatitis (NASH). Current therapies for patients with NAFLD include lifestyle modification. Vitamin E and pioglitazone are recommended for those confirmed to have NASH. However, there are concerns about the long-term safety of both pioglitazone and vitamin E in higher doses. Metformin is essential for managing the abnormal metabolic parameters in patients with NAFLD. Glucagon-like peptide-1 analogue, sodium-dependent glucose cotransporter inhibitors, and peroxisome proliferator-activated receptor agonists have shown benefits in improving metabolic parameters and reducing hepatic lipid accumulation and inflammation. However, the role of these antidiabetic agents in specifically reversing NASH needs to be established. Indeed, statins have been underprescribed in patients with NASH owing to fear of hepatotoxicity despite coronary artery disease being a common cause of death in patients with NAFLD. Statins reduce the risk of cardiovascular morbidity and mortality in patients with NASH and dyslipidemia. However, their use specifically for treatment of NASH needs further evaluation. Optimizing the control of risk factors remains the main strategy for treatment until targeted pharmacotherapies for NASH are available.

A 17-Beta-Hydroxysteroid Dehydrogenase 13 Variant Protects From Hepatocellular Carcinoma Development in Alcoholic Liver Disease

Recently, a loss of function variant (rs72613567) in 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13) has been identified as protective of nonalcoholic (NAFLD) and alcoholic liver disease (ALD). However, the role of this single-nucleotide polymorphism (SNP) in the development of hepatocellular carcinoma (HCC) is currently unknown. A total of 3,315 European patients with HCC (n = 1,109) or without HCC, but with chronic liver disease (CLD; n = 2,206), from four centers were analyzed either by whole-exome sequencing (WES; exploratory cohort, 285 HCC) or genotyped for HSD17B13 rs72613567 (validation cohort, 824 HCC and all CLD). We included a control group of 33,337 healthy European individuals from the Exome Aggregation Consortium. We compared distribution of genotype using the chi-square test and logistic regression. In the exploratory cohort analyzed by WES, frequency of the TA allele of HSD17B13 rs72613567 was significantly decreased in HCC patients compared to healthy controls (P = 1.52 × 10^-06 ). In the validation cohort, frequency of TA allele carriers was also decreased in patients with CLD and without HCC (39%) compared to healthy individuals (47%; P < 0.0001). The protective effect of the TA allele of HSD17B13 rs72613567 was identified in patients with ALD (odds ratio [OR] = 0.73; 95% confidence interval [CI], 0.65-0.82; P < 0.0001), NAFLD (OR = 0.64; 95% CI, 0.49-0.83; P = 0.0007), and hepatitis C (OR = 0.71; 95% CI, 0.60-0.85; P = 0.0002). In patients with ALD, the proportion of TA allele carriers with HCC was significantly lower (32%) than in CLD patients without HCC (40%), even after adjustment for age, sex, and fibrosis (OR = 0.64; 95% CI, 0.46-0.87; P = 0.005). Conclusion: The HSD17B13 rs72613567 loss of function variant is protective of HCC development in patients with ALD.

From NASH to HCC: current concepts and future challenges

Caloric excess and sedentary lifestyle have led to a global epidemic of obesity and metabolic syndrome. The hepatic consequence of metabolic syndrome and obesity, nonalcoholic fatty liver disease (NAFLD), is estimated to affect up to one-third of the adult population in many developed and developing countries. This spectrum of liver disease ranges from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Owing to the high prevalence of NAFLD, especially in industrialized countries but also worldwide, and the consequent burden of progressive liver disease, there is mounting epidemiological evidence that NAFLD has rapidly become a leading aetiology underlying many cases of hepatocellular carcinoma (HCC). In this Review, we discuss NAFLD-associated HCC, including its epidemiology, the key features of the hepatic NAFLD microenvironment (for instance, adaptive and innate immune responses) that promote hepatocarcinogenesis and the management of HCC in patients with obesity and associated metabolic comorbidities. The challenges and future directions of research will also be discussed, including clinically relevant biomarkers for early detection, treatment stratification and monitoring as well as approaches to therapies for both prevention and treatment in those at risk or presenting with NAFLD-associated HCC.

Independent and additive effects of PNPLA3 and TM6SF2 polymorphisms on the development of non-B, non-C hepatocellular carcinoma

BACKGROUND

This study was aimed at evaluating the association between single nucleotide polymorphisms (SNPs) in the PNPLA3, NCAN, TM6SF2 and MBOAT7 and hepatocellular carcinoma (HCC) development in Thai patients according to underlying etiologies of liver disease.

METHODS

These SNPs were determined by allelic discrimination in blood samples of 105 healthy controls and 530 patients with HCC [270 with hepatitis B virus (HBV-HCC), 131 with hepatitis C virus (HCV-HCC), and 129 with non-B, non-C HCC (NBNC-HCC) matched for age and gender].

RESULTS

G allele of PNPLA3 rs738409 variant was significantly higher in NBNC-HCC (49%) compared to healthy controls (32%), HBV-HCC (32%) and HCV-HCC (31%) (P < 0.001). T allele of TM6SF2 rs58542926 was more prevalent in NBNC-HCC (24%) than in healthy controls (8%), HBV-HCC (10%) and HCV-HCC (12%) (P < 0.001). The distribution of NCAN (rs2228603) and MBOAT7 (rs641738) was not different between groups. In multivariate logistic regression analysis, PNPLA3 rs738409 (OR 2.06, 95% CI 1.24-3.43; P = 0.005) and TM6SF2 rs58542926 (OR 2.22, 95% CI 1.34-3.65; P = 0.002) were independently associated with NBNC-HCC compared to viral-related HCC (VR-HCC). The proportion of patients with NBNC-HCC increased significantly along with the increase of the number of risk alleles. There was no association between these SNPs and overall survival in patients with HCC.

CONCLUSIONS

These data showed that PNPLA3 and TM6SF2 polymorphisms were independently linked to NBNC-HCC but not HBV- or HCV-HCC in Thai populations. In addition, the risk genotypes might interact with each other through tumor development in patients with NBNC-HCC.

Correlation between PNPLA3 rs738409 polymorphism and hepatocellular carcinoma: a meta-analysis of 10,330 subjects

PURPOSE

The correlation between patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 polymorphism and hepatocellular carcinoma was investigated by several pilot studies, but the results of these studies were controversial. Therefore, we performed this study to better assess the relationship between PNPLA3 rs738409 polymorphism and the likelihood of hepatocellular carcinoma.

METHODS

Eligible studies were searched in PubMed, Medline, EMBASE, and Web of Science. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationship between PNPLA3 rs738409 polymorphism and hepatocellular carcinoma.

RESULTS

A total of 17 studies with 10,330 participants were analyzed. A significant association with the likelihood of hepatocellular carcinoma was detected for the PNPLA3 rs738409 polymorphism in dominant (P = 0.0001; OR 0.66; 95% CI 0.53, 0.82), recessive (P < 0.0001; OR 2.32; 95% CI 1.76, 3.06) and allele (P < 0.0001; OR 0.64; 95% CI 0.53, 0.77) comparisons. Further subgroup analyses revealed that the PNPLA3 rs738409 polymorphism was significantly associated with the likelihood of hepatocellular carcinoma in Caucasians (dominant model: P < 0.0001, OR 0.57, 95% CI 0.45, 0.71; recessive model: P < 0.0001, OR 2.74, 95% CI 2.02, 3.71; allele model: P < 0.0001, OR 0.56, 95% CI 0.46, 0.67). However, no positive results were detected in Asians.

CONCLUSIONS

Our findings indicated that the PNPLA3 rs738409 polymorphism may serve as a potential biological marker of hepatocellular carcinoma in Caucasians.

Trends in hepatocellular carcinoma due to non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and is associated with hepatocellular carcinoma (HCC), the most frequent malignant liver tumor. The increasing prevalence of obesity and diabetes is influencing the epidemiology of HCC with the most dramatic increases in NAFLD-related HCC seen in Western countries. Although cirrhosis is the major risk factor for HCC in NAFLD, there is increasing recognition that NAFLD-HCC occurs in the absence of cirrhosis. Areas covered: The epidemiology of NAFLD related HCC and its impact on changing the incidence of HCC globally. We overview risk factors for NAFLD-HCC in the presence and absence of cirrhosis and examine trends in liver transplantation (LT) related to NAFLD-HCC. Expert commentary: The incidence of NAFLD-related cirrhosis will continue to rise globally in parallel with risk factors of obesity and diabetes. Consequently, NAFLD-related HCC will become an increasingly important cause of liver-related morbidity and mortality and a common indication for LT worldwide. Further identification of risk factors for NAFLD-HCC and effective treatments for NAFLD are required to reduce this future burden of disease.

Effect of luseogliflozin on hepatic fat content in type 2 diabetes patients with non-alcoholic fatty liver disease: A prospective, single-arm trial (LEAD trial)

AIMS

No pharmacological therapies are approved for non-alcoholic fatty liver disease (NAFLD). Luseogliflozin, a sodium glucose cotransporter 2 inhibitor, has been developed for the treatment of adults with type 2 diabetes (T2DM). The aim of this prospective, single-arm study is to evaluate the efficacy of luseogliflozin on hepatic fat content and glycated hemoglobin (HbA1c) in T2DM patients with NAFLD.

METHODS

Forty T2DM patients with NAFLD were treated with luseogliflozin 2.5 mg/day for 24 weeks. Primary end-points were changes in HbA1c and hepatic steatosis evaluated by magnetic resonance imaging-hepatic fat fraction from baseline. Secondary end-points were changes in metabolic and hepatic function-related parameters, including hepatic fibrosis markers (Fibrosis-4 index, NAFLD fibrosis score, type IV collagen 7S. and Wisteria floribunda agglutinin-positive Mac-2 binding protein).

RESULTS

Not only HbA1c and transaminase activities but also hepatic fat content were significantly decreased after 24 weeks of therapy with luseogliflozin. The reduction of hepatic fat content was significantly correlated with the reduction of alanine aminotransferase. Although hepatic fibrosis markers were unchanged, serum ferritin levels reduced and serum albumin significantly increased after the treatment.

CONCLUSION

Luseogliflozin can be a novel promising agent for the treatment of T2DM patients with NAFLD. Prospective randomized controlled trials are warranted to confirm this impact of luseogliflozin onT2DM with NAFLD.

PNPLA3 and TM6SF2 variants as risk factors of hepatocellular carcinoma across various etiologies and severity of underlying liver diseases

Few single nucleotide polymorphisms (SNPs) have been reproducibly associated with hepatocellular carcinoma (HCC). Our aim was to test the association between nine SNPs and HCC occurrence. SNPs in genes linked to HCC (DEPDC5, GRIK1, KIF1B, STAT4, MICA, DLC1, DDX18) or to liver damage (PNPLA3-rs738409, TM6SF2-rs58542926) in GWAS were genotyped in discovery cohorts including 1,020 HCC, 2,021 controls with chronic liver disease and 2,484 healthy individuals and replication was performed in prospective cohorts of cirrhotic patients with alcoholic liver disease (ALD, n = 249) and hepatitis C (n = 268). In the discovery cohort, PNPLA3 and TM6SF2 SNPs were associated with HCC (OR = 1.67 [CI95%:1.16-2.40], p = 0.005; OR = 1.45 [CI95%:1.08-1.94], p = 0.01) after adjustment for fibrosis, age, gender and etiology. In contrast, STAT4-rs7574865 was associated with HCC only in HBV infected patients (p = 0.03) and the other tested SNP were not linked with HCC risk. PNPLA3 and TM6SF2 variants were independently associated with HCC in patients with ALD (OR = 3.91 [CI95%:2.52-6.06], p = 1.14E-09; OR = 1.79 [CI95%:1.25-2.56], p = 0.001) but not with other etiologies. PNPLA3 SNP was also significantly associated with HCC developed on a nonfibrotic liver (OR = 2.19 [CI95%:1.22-3.92], p = 0.007). The association of PNPLA3 and TM6SF2 with HCC risk was confirmed in the prospective cohort with ALD. A genetic score including PNPLA3 and TM6SF2 minor alleles showed a progressive significant increased risk of HCC in ALD patients. In conclusion, PNPLA3-rs738409 and TM6SF2-rs58542926 are inherited risk variants of HCC development in patients with ALD in a dose dependent manner. The link between PNPLA3 and HCC on nonfibrotic liver suggests a direct role in liver carcinogenesis.

Combination of PNPLA3 and TLL1 polymorphism can predict advanced fibrosis in Japanese patients with nonalcoholic fatty liver disease

BACKGROUND

Hepatic fibrosis is an independent risk factor for mortality and liver-related events in patients with nonalcoholic fatty liver disease (NAFLD). PNPLA3 rs738409 has been associated with fibrosis in viral and non-viral hepatitis. TLL1 rs17047200 also has been associated with developing hepatocellular carcinoma probably via hepatic fibrogenesis. We estimated the impact of these genetic polymorphisms on hepatic fibrosis in Japanese patients with NAFLD.

METHODS

We analyzed the association between these genetic variants and the backgrounds of 817 individuals who received health checkups (health check cohort) from 2012 to 2014. Then, we investigated the relationship between genetic variants and liver histology in 258 consecutive patients with biopsy-proven NAFLD in Japan (NAFLD cohort) from 2012 to 2017 (UMIN000027399).

RESULTS

The prevalence of PNPLA3 CG/GG in the NAFLD cohort was higher than that in the health check cohort (p < 0.001). The prevalence of patients with advanced fibrosis (stages 3-4) was higher for PNPLA3 genotype CG/GG than CC (p = 0.048) and for TLL1 genotype AT/TT than AA (p = 0.044). The high-risk group which had at least two risk alleles of these variants was more likely to have advanced fibrosis (p = 0.004). Multivariate analysis identified body mass index [odds ratio (OR) 1.123, serum AST (OR 1.037, p = 0.004], serum albumin (OR 0.247, p = 0.032), and genetic high risk (OR 2.632, p = 0.026) as predictors of advanced fibrosis.

CONCLUSIONS

In Japanese patients with NAFLD, individuals with risk alleles of PNPLA3 and TLL1 may have a risk of advanced fibrosis.