Cirrhosis and liver failure in nonalcoholic fatty liver disease: Molehill or mountain?

Worldwide long-term trends in the incidence of nonalcoholic fatty liver disease during 1990–2019: A joinpoint and age-period-cohort analysis

Background

Non-alcoholic fatty liver disease (NAFLD) was previously a neglected disease that is now becoming a worldwide pandemic. A better understanding of its incidence and long-term trends will help to increase public awareness of the disease and the development of future prevention strategies.

Methods

The incidence rates of NAFLD during 1990–2019 were collected from the Global Burden of Disease Study 2019 database according to the following parameters: sex, age, socio-demographic index, and geographical region. Estimated annual percentage changes and joinpoint models were used to assess the long-term trend of NAFLD, and an age-period-cohort model was used to assess the extents of the age, period, and cohort effects.

Results

Adult males, postmenopausal females, Latin American populations, and people in developing countries had a high risk of developing NAFLD. The joinpoint model indicated a new trend of increasing NAFLD incidence in 2005. Age was a risk factor affecting NAFLD incidence, with this effect increasing in more-recent periods. Younger birth cohorts had lower risks of NAFLD.

Conclusions

Recent prevention measures for NAFLD have achieved good initial results. However, it remains a high priority to increase the public awareness of this condition, develop its diagnostic criteria, identify cost-effective screening methods, and seek policy support to act against NAFLD, which will be a major public health problem in the future.

Expression of IGF-1 receptor and GH receptor in hepatic tissue of patients with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

OBJECTIVE

The GH and IGF-1 axis is a candidate disease-modifying target in nonalcoholic fatty liver disease (NAFLD) given its lipolytic, anti-inflammatory and anti-fibrotic properties. IGF-1 receptor (IGF-1R) and GH receptor (GHR) expression in adult, human hepatic tissue is not well understood across the spectrum of NAFLD severity. Therefore, we sought to investigate hepatic IGF-1R and GHR expression in subjects with NAFLD utilizing gene expression analysis (GEA) and immunohistochemistry (IHC).

DESIGN

GEA (n = 318) and IHC (n = 30) cohorts were identified from the Massachusetts General Hospital NAFLD Tissue Repository. GEA subjects were categorized based on histopathology as normal liver histology (NLH), steatosis only (Steatosis), nonalcoholic steatohepatitis (NASH) without fibrosis (NASH F0), and NASH with fibrosis (NASH F1-4) with GEA by the Nanostring nCounter assay. IHC subjects were matched for age, body mass index (BMI), sex, and diabetic status across three groups (n = 10 each): NLH, Steatosis, and NASH with fibrosis (NASH F1-3). IHC for IGF-1R, IGF-1 and GHR was performed on formalin-fixed, paraffin-embedded hepatic tissue samples.

RESULTS

IGF-1R gene expression did not differ across NAFLD severity while IGF-1 gene expression decreased with increasing NAFLD severity, including when controlled for BMI and age. GHR expression did not differ by severity of NAFLD based on GEA or IHC.

CONCLUSIONS

IGF-1R and GHR expression levels were not significantly different across NAFLD disease severity. However, expression of IGF-1 was lower with increasing severity of NAFLD. Additional research is needed regarding the contribution of the GH/IGF-1 axis to the pathophysiology of NAFLD and NASH.

SOCS2 Suppresses Inflammation and Apoptosis during NASH Progression through Limiting NF-κB Activation in Macrophages

Background: Inflammation and apoptosis play a crucial role in the progression of nonalcoholic steatohepatitis (NASH). Suppressor of cytokine signaling 2 (SOCS2) is one of classic negative regulators of cytokine signaling, which has recently been described as anti-inflammatory mediators. However, the role of SOCS2 in macrophages during NASH progression and the relationship among SOCS2, inflammation, apoptosis and NASH is largely unknown. Herein, we aimed to study the function of SOCS2 in NASH progression.

Methods: We detected SOCS2 expression in macrophages in human subjects without steatosis, with simple steatosis and with NASH to confirm the relationship between SOCS2 and NASH. Free fatty acids was used to establish stress environment in RAW 264.7 cell lines stably overexpressing or knockdown SOCS2. In vitro and vivo assays also performed to study the molecular function of SOCS2 in NASH progression.

Findings: Our human samples illustrated that SOCS2 was decreased in macrophages during NASH progression and was negatively correlated to NASH level. Meanwhile, In vitro assays showed SOCS2 overexpression in macrophages suppressed inflammation and apoptosis via inhibiting NF-κB signaling pathway, while SOCS2 knock-down in macrophages caused an increased activation of NF-κB, which could be blocked by ammonium 1-pyrrolidinedithiocarbamate (PDTC). In addition, SOCS2 in macrophages also suppressed inflammation via limiting the activation of inflammasomes. Consistent with these, our BMT model also confirmed the SOCS2 function in macrophages during NASH.

Interpretation: Our data strongly indicate that SOCS2 plays a role in inhibiting inflammation and apoptosis via NF-κB and inflammasome signaling pathway in macrophages during NASH. Further studies are required to explore the potential preventive and therapeutic strategies of SOCS2 for this common liver disease.

Estimation of Liver Fat by FibroScan in Patients With Nonalcoholic Fatty Liver Disease

Background

Assessment of nonalcoholic fatty liver disease (NAFLD) includes estimation of liver fat (steatosis). Controlled attenuation parameter (CAP) value obtained by FibroScan^® (Echosens, Paris, France) is an alternative to liver biopsy for diagnosing and estimating steatosis (S). This study aimed to estimate the liver fat by CAP in NAFLD patients.

Methods

An observational cross-sectional study was conducted at the Liver Unit of Bir Hospital, from January 2021 to May 2021 after ethical clearance from the Institutional Review Board of the National Academy of Medical Sciences. A convenient sampling method was used. Data were analyzed with descriptive and inferential statistics involving bivariate and multivariate analysis.

Results

A total of 127 NAFLD patients were enrolled. The mean (±SD) CAP value was 271.53 (±50.69) dB/m. Total cholesterol, triglyceride, and body mass index (BMI) correlated positively (p<0.05) while systolic blood pressure correlated negatively with CAP value (p=0.031). On multivariate analysis, patients with BMI ≥25 kg/m² were found 3.7 times more likely to have CAP ≥291 dB/m (S3, severe steatosis) than those with BMI <25 kg/m² (p=0.048, 95% CI 1.01, 13.50). The mean (±SD) CAP values were 276.19 (±49.93) and 246.60 (±48.50) dB/m among those with BMI ≥25 kg/m² and <25 kg/m², respectively (p=0.016, using independent t-test). CAP steatosis grading correlated positively with both the ultrasound grading (p<0.001) and fibrosis grading by liver stiffness measurement (p=0.004). 

Conclusion

In this observational cross-sectional study of NAFLD patients, the mean (±SD) CAP value was 271.53 (±50.69) dB/m, which corresponds to moderate steatosis (S2). Obese NAFLD patients with ≥25 kg/m² were 3.7 times more likely to have severe steatosis (S3) than nonobese NAFLD patients with BMI <25 kg/m².

Ginseng Saponin Enriched in Rh1 and Rg2 Ameliorates Nonalcoholic Fatty Liver Disease by Inhibiting Inflammasome Activation

Nonalcoholic fatty liver disease (NAFLD) is becoming one of the most common chronic liver diseases in the world. One of the features of NAFLD is hepatic fat accumulation, which further causes hepatic steatosis, fibrosis, and inflammation. Saponins, the major pharmacologically active ingredients isolated from Panax notoginseng, contain several ginsenosides, which have various pharmacological and therapeutic functions. However, the ginsenoside-specific molecular mechanism of saponins in NAFLD remains unknown. This study aimed to elucidate the effects of ginseng saponin extract and its ginsenosides on hepatic steatosis, fibrosis, and inflammation and their underlying action mechanism in NAFLD. Mice were fed a fast food diet (FFD) for 16 weeks to induce NAFLD and then treated with saponin extract (50 or 150 mg/kg) for the remaining nine weeks to determine the effects of saponin on NAFLD. Saponin extract administration significantly alleviated FFD-induced hepatic steatosis, fibrosis, and inflammation. Particularly, saponin extract, compared with conventional red ginseng, contained significantly increased amounts of ginsenosides (Rh1 (10.34-fold) and Rg2 (7.1-fold)). In vitro Rh1 and Rg2 treatments exerted an anti-steatotic effect in primary hepatocytes, an antifibrotic effect in hepatic stellate cells, and anti-inflammatory and pro-mitophagy effects in immortalized mouse Kupffer cells. Mechanistically, saponin extract alleviated lipopolysaccharide-induced NLRP3 inflammasome activation by promoting mitophagy. In conclusion, saponin extract inhibited inflammation-mediated pathological inflammasome activation in macrophages, thereby preventing NAFLD development. Thus, saponin extract administration may be an alternative method for NAFLD prevention.

Association between Nonalcoholic Fatty Liver Disease and Endocrinopathies: Clinical Implications

Nonalcoholic fatty liver disease (NAFLD) has a rising prevalence worldwide. Its potential for evolution towards liver cirrhosis and hepatocellular carcinoma, as well as associations with extrahepatic manifestations, represents a double burden for patients and physicians alike. Recently, there has been increasing evidence of the association between NAFLD and a number of endocrinopathies, such as hypothyroidism, polycystic ovarian syndrome (PCOS), hypopituitarism, growth hormone deficiency (GHD), hypogonadism, and hypercortisolism. Definite correlations are supported by clear evidence so far, but further studies are needed in order to completely clarify the pathogenic mechanisms and, especially, to identify therapeutic implications. In this review, we present the main relationships between NAFLD and endocrinopathies, emphasizing the reciprocal causality, evolutive interconnections, and current clinical scenarios of presentations of which the clinicians should be aware.

PTPROt aggravates inflammation by enhancing NF-κB activation in liver macrophages during nonalcoholic steatohepatitis

Rationale: Inflammation plays a crucial role in the progression of nonalcoholic steatohepatitis (NASH). Protein tyrosine phosphatase receptor type O truncated isoform (PTPROt) is an integral membrane protein that has been identified in osteoclasts, macrophages, and B lymphocytes. However, its relationship between inflammation and NASH is largely unknown. Herein, we aimed to study the function of PTPROt in NASH progression.

Methods: We established a NASH mouse model in wild-type (WT), PTPRO knockout mice by western diet (WD) and methionine-choline-deficient diet (MCD). In addition, MCD-induced NASH model was established in BMT mice. Moreover, we determined the expression of PTPROt in liver macrophages in human subjects without steatosis, with simple steatosis, and with NASH to confirm the relationship between PTPROt and NASH. In vitro assays were also performed to study the molecular role of PTPROt in NASH progression.

Results: Human samples and animal model results illustrated that PTPROt is increased in liver macrophages during NASH progression and is positively correlated with the degree of NASH. Our animal model also showed that PTPROt in liver macrophages can enhance the activation of the NF-κB signaling pathway, which induces the transcription of genes involved in the inflammatory response. Moreover, PTPROt promotes the transcription of pro-oxidant genes and inhibits antioxidant and protective genes via increased activation of the NF-κB signaling pathway, thereby causing an increased level of reactive oxygen species (ROS) and damaged mitochondria. This triggers the NLRP3-IL1β axis and causes a heightened inflammatory response. Notably, PTPROt partially limits inflammation and ROS production by promoting mitophagy, which participates in a negative feedback loop in this model.

Conclusions: Our data strongly indicate that PTPROt plays a dual role in inflammation via the NF-κB signaling pathway in liver macrophages during NASH. Further studies are required to explore therapeutic strategies and prevention of this common liver disease through PTPROt.

Diagnostic Accuracy of Shear Wave Elastography as a Non-invasive Biomarker of High-Risk Non-alcoholic Steatohepatitis in Patients with Non-alcoholic Fatty Liver Disease

In this study, we evaluated the diagnostic accuracy of shear wave elastography (SWE) for differentiating high-risk non-alcoholic steatohepatitis (hrNASH) from non-alcoholic fatty liver and low-risk non-alcoholic steatohepatitis (NASH). Patients with non-alcoholic fatty liver disease scheduled for liver biopsy underwent pre-biopsy SWE. Ten SWE measurements were obtained. Biopsy samples were reviewed using the NASH Clinical Research Network Scoring System and patients with hrNASH were identified. Receiver operating characteristic curves for SWE-based hrNASH diagnosis were charted. One hundred sixteen adult patients underwent liver biopsy at our institution for the evaluation of non-alcoholic fatty liver disease. The area under the receiver operating characteristic curve of SWE for hrNASH diagnosis was 0.73 (95% confidence interval: 0.61-0.84, p < 0.001). The Youden index-based optimal stiffness cutoff value for hrNASH diagnosis was calculated as 8.4 kPa (1.67 m/s), with a sensitivity of 77% and specificity of 66%. SWE may be useful for the detection of NASH patients at risk of long-term liver-specific morbidity and mortality.

Prevalence, trends, outcomes, and disparities in hospitalizations for nonalcoholic fatty liver disease in the United States

Background

As the frequency of nonalcoholic fatty liver disease (NAFLD) continues to rise in the United States (US) community, more patients are hospitalized with NAFLD. However, data on the prevalence and outcomes of hospitalizations with NAFLD are lacking. We investigated the prevalence, trends and outcomes of NAFLD hospitalizations in the US.

Methods

Hospitalizations with NAFLD were identified in the National Inpatient Sample (2007-2014) by their ICD-9-CM codes, and the prevalence and trends over an 8-year period were calculated among different demographic groups. After excluding other causes of liver disease among the NAFLD cohorts (n=210,660), the impact of sex, race and region on outcomes (mortality, discharge disposition, length of stay [LOS], and cost) were computed using generalized estimating equations (SAS 9.4).

Results

Admissions with NAFLD tripled from 2007-2014 at an average rate of 79/100,000 hospitalizations/year (P<0.0001), with a larger rate of increase among males vs. females (83/100,000 vs. 75/100,000), Hispanics vs. Whites vs. Blacks (107/100,000 vs. 80/100,000 vs. 48/100,000), and government-insured or uninsured patients vs. privately-insured (94/100,000 vs. 74/100,000). Males had higher mortality, LOS, and cost than females. Blacks had longer LOS and poorer discharge destination than Whites; while Hispanics and Asians incurred higher cost than Whites. Uninsured patients had higher mortality, longer LOS, and poorer discharge disposition than the privately-insured.

Conclusions

Hospitalizations with NAFLD are rapidly increasing in the US, with a disproportionately higher burden among certain demographic groups. Measures are required to arrest this ominous trend and to eliminate the disparities in outcome among patients hospitalized with NAFLD.

Toward an accelerated adoption of data-driven findings in medicine : Research, skepticism, and the need to speed up public visibility of data-driven findings

To accelerate the adoption of a new method with a high potential to replace or extend an existing, presumably less accurate, medical scoring system, evaluation should begin days after the new concept is presented publicly, not years or even decades later. Metaphorically speaking, as chameleons capable of quickly changing colors to help their bodies adjust to changes in temperature or light, health-care decision makers should be capable of more quickly evaluating new data-driven insights and tools and should integrate the highest performing ones into national and international care systems. Doing so is essential, because it will truly save the lives of many individuals.

Marijuana is not associated with progression of hepatic fibrosis in liver disease: a systematic review and meta-analysis

BACKGROUND

An estimated 22 million adults use marijuana in the USA. The role of marijuana in the progression of hepatic fibrosis remains unclear.

AIMS

We carried out a systematic review and meta-analysis to evaluate the impact of marijuana on prevalence and progression of hepatic fibrosis in chronic liver disease.

PATIENTS AND METHODS

We searched several databases from inception through 10 November 2017 to identify studies evaluating the role of marijuana in chronic liver disease. Our main outcome of interest was prevalence/progression of hepatic fibrosis. Adjusted odds ratios (ORs) and hazards ratios (HRs) were pooled and analyzed using random-effects model.

RESULTS

Nine studies with 5 976 026 patients were included in this meta-analysis. Prevalence of hepatic fibrosis was evaluated in nonalcoholic fatty liver disease (NAFLD), hepatitis C virus (HCV), and hepatitis C and HIV coinfection by two, four, and one studies. Progression of hepatic fibrosis was evaluated by two studies. Pooled OR for prevalence of fibrosis was 0.91 (0.72-1.15), I=75%. On subgroup analysis, pooled OR among NAFLD patients was 0.80 (0.75-0.86), I=0% and pooled OR among HCV patients was 1.96 (0.78-4.92), I=77%. Among studies evaluating HR, pooled HR for progression of fibrosis in HCV-HIV co-infected patients was 1.03 (0.96-1.11), I=0%.

CONCLUSION

Marijuana use did not increase the prevalence or progression of hepatic fibrosis in HCV and HCV-HIV-coinfected patients. On the contrary, we noted a reduction in the prevalence of NAFLD in marijuana users. Future studies are needed to further understand the therapeutic impact of cannabidiol-based formulations in the management of NAFLD.

Salidroside Attenuates High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease via AMPK-Dependent TXNIP/NLRP3 Pathway

Our previous studies suggested that salidroside could alleviate hepatic steatosis in type 2 diabetic C57BLKS/Lepr^db (db/db) mice. The aim of the present study was to evaluate the therapeutic effect of salidroside on high-fat diet- (HFD-) induced nonalcoholic fatty liver disease (NAFLD) by investigating underlying mechanisms. Mice were fed with HFD or regular diet, randomly divided into two groups, and treated with salidroside or vehicle for 8 weeks. Then, biochemical analyses and histopathological examinations were conducted in vivo and in vitro. Salidroside administration attenuated HFD-induced obesity, blood glucose variability, and hepatic lipid deposition, markedly increasing insulin sensitivity in HFD mice. In addition, salidroside suppressed oxidative stress, thioredoxin-interacting protein (TXNIP) expression, and NLRP3 inflammasome activation in the liver. In cultured hepatocytes, salidroside dose dependently regulated lipid accumulation, reactive oxygen species (ROS) generation, and NLRP3 inflammasome activation as well as improved AMP-activated protein kinase (AMPK) activity and insulin sensitivity. The inhibition of AMPK activation by inhibitor or short interfering RNA (siRNA) resulted in the suppression of the beneficial effects of salidroside in hepatocytes. Our findings demonstrated that salidroside protects against NAFLD by improving hepatic lipid metabolism and NLRP3 inflammasome activation, and these actions are related to the regulation of the oxidative stress and AMPK-dependent TXNIP/NLRP3 pathways.

Hepatic connexin 32 associates with nonalcoholic fatty liver disease severity

Emerging data highlight the critical role for the innate immune system in the progression of nonalcoholic fatty liver disease (NAFLD). Connexin 32 (Cx32), the primary liver gap junction protein, is capable of modulating hepatic innate immune responses and has been studied in dietary animal models of steatohepatitis. In this work, we sought to determine the association of hepatic Cx32 with the stages of human NAFLD in a histologically characterized cohort of 362 patients with NAFLD. We also studied the hepatic expression of the genes and proteins known to interact with Cx32 (known as the connexome) in patients with NAFLD. Last, we used three independent dietary mouse models of nonalcoholic steatohepatitis to investigate the role of Cx32 in the development of steatohepatitis and fibrosis. In a univariate analysis, we found that Cx32 hepatic expression associates with each component of the NAFLD activity score and fibrosis severity. Multivariate analysis revealed that Cx32 expression most closely associated with the NAFLD activity score and fibrosis compared to known risk factors for the disease. Furthermore, by analyzing the connexome, we identified novel genes related to Cx32 that associate with NAFLD progression. Finally, we demonstrated that Cx32 deficiency protects against liver injury, inflammation, and fibrosis in three murine models of nonalcoholic steatohepatitis by limiting initial diet-induced hepatoxicity and subsequent increases in intestinal permeability. Conclusion: Hepatic expression of Cx32 strongly associates with steatohepatitis and fibrosis in patients with NAFLD. We also identify novel genes associated with NAFLD and suggest that Cx32 plays a role in promoting NAFLD development. (Hepatology Communications 2018;2:786-797).

Sex Differences in Body Composition

Body composition differs between men and women. Men have more lean mass, and women have more fat mass than men. Men are more likely to accumulate adipose tissue around the trunk and abdomen, whereas women usually accumulate adipose tissue around the hips and thighs. Less is known about sex differences in ectopic fat depots. Advances in imaging allow the noninvasive assessment of abdominal and femorogluteal fat compartments, intramyocellular lipids, intrahepatic lipids, pericardial adipose tissue, and neck adipose tissue including brown adipose tissue and tongue adipose tissue. In this review, sex differences of regional adipose tissue, muscle mass, ectopic lipids, and brown adipose tissue and their effects on cardiometabolic risk will be discussed. In addition, novel imaging techniques to quantify these body composition compartments noninvasively will be described.

Trends in Characteristics of Patients Listed for Liver Transplantation Will Lead to Higher Rates of Waitlist Removal Due to Clinical Deterioration

BACKGROUND

Changes in the epidemiology of end-stage liver disease may lead to increased risk of dropout from the liver transplant waitlist. Anticipating the future of liver transplant waitlist characteristics is vital when considering organ allocation policy.

METHODS

We performed a discrete event simulation to forecast patient characteristics and rate of waitlist dropout. Estimates were simulated from 2015 to 2025. The model was informed by data from the Organ Procurement and Transplant Network, 2003 to 2014. National data are estimated along with forecasts for 2 regions.

RESULTS

Nonalcoholic steatohepatitis will increase from 18% of waitlist additions to 22% by 2025. Hepatitis C will fall from 30% to 21%. Listings over age 60 years will increase from 36% to 48%. The hazard of dropout will increase from 41% to 46% nationally. Wait times for transplant for patients listed with a Model for End-Stage Liver Disease (MELD) between 22 and 27 will double. Region 5, which transplants at relatively higher MELD scores, will experience an increase from 53% to 64% waitlist dropout. Region 11, which transplants at lower MELD scores, will have an increase in waitlist dropout from 30% to 44%.

CONCLUSIONS

The liver transplant waitlist size will remain static over the next decade due to patient dropout. Liver transplant candidates will be older, more likely to have nonalcoholic steatohepatitis and will wait for transplantation longer even when listed at a competitive MELD score. There will continue to be significant heterogeneity among transplant regions where some patients will be more likely to drop out of the waitlist than receive a transplant.

Cannabis use is associated with reduced prevalence of non-alcoholic fatty liver disease: A cross-sectional study

Cannabis use is associated with reduced prevalence of obesity and diabetes mellitus (DM) in humans and mouse disease models. Obesity and DM are a well-established independent risk factor for non-alcoholic fatty liver disease (NAFLD), the most prevalent liver disease globally. The effects of cannabis use on NAFLD prevalence in humans remains ill-defined. Our objective is to determine the relationship between cannabis use and the prevalence of NAFLD in humans. We conducted a population-based case-control study of 5,950,391 patients using the 2014 Healthcare Cost and Utilization Project (HCUP), Nationwide Inpatient Survey (NIS) discharge records of patients 18 years and older. After identifying patients with NAFLD (1% of all patients), we next identified three exposure groups: non-cannabis users (98.04%), non-dependent cannabis users (1.74%), and dependent cannabis users (0.22%). We adjusted for potential demographics and patient related confounders and used multivariate logistic regression (SAS 9.4) to determine the odds of developing NAFLD with respects to cannabis use. Our findings revealed that cannabis users (dependent and non-dependent) showed significantly lower NAFLD prevalence compared to non-users (AOR: 0.82[0.76-0.88]; p<0.0001). The prevalence of NAFLD was 15% lower in non-dependent users (AOR: 0.85[0.79-0.92]; p<0.0001) and 52% lower in dependent users (AOR: 0.49[0.36-0.65]; p<0.0001). Among cannabis users, dependent patients had 43% significantly lower prevalence of NAFLD compared to non-dependent patients (AOR: 0.57[0.42-0.77]; p<0.0001). Our observations suggest that cannabis use is associated with lower prevalence of NAFLD in patients. These novel findings suggest additional molecular mechanistic studies to explore the potential role of cannabis use in NAFLD development.

Association between soil heavy metals and fatty liver disease in men in Taiwan: a cross sectional study

OBJECTIVES

Metabolic factors are major risk factors for non-alcoholic fatty liver disease although other factors may also contribute to development of fatty liver disease. We explored the association between exposure to soil heavy metals and prevalence of fatty liver disease.

METHODS

We retrospectively analysed data from patients diagnosed with fatty liver disease in 2014 at the Health Evaluation Centre of Chang-Hua Christian Hospital (n=1137). We used residency data provided in the records of the Health Evaluation Centre and data for soil metal concentrations from a nationwide survey conducted by the Environmental Protection Administration of Taiwan. We studied the correlations between the severity of fatty liver disease and concentrations of soil heavy metals (arsenic, mercury, cadmium, chromium, copper, nickel, lead and zinc).

RESULTS

The prevalence of moderate to severe fatty liver disease in our study was 26.5%. Using univariate and multivariate analysis, we demonstrated that the presence of soil heavy metals was a significant risk factor for fatty liver disease in men (OR 1.83, 95% CI 1.161 to 2.899, p=0.009). With stratification by body mass index (BMI) and gender, lean men with a BMI <24 kg/m² were the most susceptible to soil heavy metals (OR 5.059, 95% CI 1.628 to 15.728, p<0.05).

CONCLUSIONS

Our study suggested a significant association between exposure to soil heavy metals and fatty liver disease in lean men.

Diabetes Is Associated with Clinical Decompensation Events in Patients with Cirrhosis

OBJECTIVES

Liver cirrhosis is a leading cause of morbidity and mortality in the USA. Diabetes is common and increasing in incidence. Patients with compensated cirrhosis and diabetes may be at greater risk of clinical decompensation. We examined the risk of decompensation among a large sample of working-aged insured patients dually diagnosed with compensated cirrhosis and diabetes.

METHODS

This retrospective study used MarketScan^® Commercial Claims and Encounters and Medicare Supplemental Databases (2000-2013). Decompensation events included incident ascites, spontaneous bacterial peritonitis, variceal bleeding, hepatic encephalopathy, acute renal failure, and hepatocellular carcinoma. Dually diagnosed patients were defined as patients with cirrhosis and diabetes using previously published ICD-9 coding strategies. Adjusted odds ratios (ORs), hazard ratios (HRs), and confidence intervals (CI) were estimated using logistic regression and Cox proportional hazard models.

RESULTS

Of 72,731 patients with compensated cirrhosis, 20,477 patients (28.15 %) were diagnosed with diabetes. After controlling for patient characteristics and medication usage, the odds of developing any decompensation event were 1.14 times higher for patients with cirrhosis and diabetes than for patients with cirrhosis only (95 % CI 1.08-1.21, P value <0.01). In the Cox proportional hazard model, patients who were dually diagnosed with diabetes had a 1.32 times higher HR (95 % CI 1.26-1.39, P value <0.01) after controlling for time-to-event.

CONCLUSIONS

Patients dually diagnosed with compensated cirrhosis and diabetes had a higher risk of having decompensation events. Careful management of diabetes in patients with liver disease may reduce the risk of clinical decompensation in this population.

Medical and Surgical Treatment Options for Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in the USA with a growing prevalence worldwide. Nonalcoholic steatohepatitis (NASH), progressive form of NAFLD, can lead to the development of cirrhosis, hepatocellular carcinoma, and the need for liver transplantation. Treatment of NASH may decrease the risk of progressive disease. Treatment for NAFLD should center around weight loss and exercise. Pharmacotherapy with vitamin E and pioglitazone should be considered for those with NASH, especially those with fibrosis. Weight loss surgery is also an effective treatment for NASH in individuals with other indications for surgery. In this review, we will discuss the currently available therapies for NASH including lifestyle, pharmacologic, and surgical options.

Development and Validation of an Algorithm to Identify Nonalcoholic Fatty Liver Disease in the Electronic Medical Record

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Risk factors for NAFLD disease progression and liver-related outcomes remain incompletely understood due to the lack of computational identification methods. The present study sought to design a classification algorithm for NAFLD within the electronic medical record (EMR) for the development of large-scale longitudinal cohorts.

METHODS

We implemented feature selection using logistic regression with adaptive LASSO. A training set of 620 patients was randomly selected from the Research Patient Data Registry at Partners Healthcare. To assess a true diagnosis for NAFLD we performed chart reviews and considered either a documentation of a biopsy or a clinical diagnosis of NAFLD. We included in our model variables laboratory measurements, diagnosis codes, and concepts extracted from medical notes. Variables with P < 0.05 were included in the multivariable analysis.

RESULTS

The NAFLD classification algorithm included number of natural language mentions of NAFLD in the EMR, lifetime number of ICD-9 codes for NAFLD, and triglyceride level. This classification algorithm was superior to an algorithm using ICD-9 data alone with AUC of 0.85 versus 0.75 (P < 0.0001) and leads to the creation of a new independent cohort of 8458 individuals with a high probability for NAFLD.

CONCLUSIONS

The NAFLD classification algorithm is superior to ICD-9 billing data alone. This approach is simple to develop, deploy, and can be applied across different institutions to create EMR-based cohorts of individuals with NAFLD.

The balance between IL-17 and IL-22 produced by liver-infiltrating T-helper cells critically controls NASH development in mice

The mechanisms responsible for the evolution of steatosis towards NASH (non-alcoholic steatohepatitis) and fibrosis are not completely defined. In the present study we evaluated the role of CD4(+) T-helper (Th) cells in this process. We analysed the infiltration of different subsets of CD4(+) Th cells in C57BL/6 mice fed on a MCD (methionine choline-deficient) diet, which is a model reproducing all phases of human NASH progression. There was an increase in Th17 cells at the beginning of NASH development and at the NASH-fibrosis transition, whereas levels of Th22 cells peaked between the first and the second expansion of Th17 cells. An increase in the production of IL (interleukin)-6, TNFα (tumour necrosis factor α), TGFβ (transforming growth factor β) and CCL20 (CC chemokine ligand 20) accompanied the changes in Th17/Th22 cells. Livers of IL-17(-/-) mice were protected from NASH development and characterized by an extensive infiltration of Th22 cells. In vitro, IL-17 exacerbated the JNK (c-Jun N-terminal kinase)-dependent mouse hepatocyte lipotoxicity induced by palmitate. IL-22 prevented lipotoxicity through PI3K (phosphoinositide 3-kinase)-mediated inhibition of JNK, but did not play a protective role in the presence of IL-17, which up-regulated the PI3K/Akt inhibitor PTEN (phosphatase and tensin homologue deleted on chromosome 10). Consistently, livers of IL-17(-/-) mice fed on the MCD diet displayed decreased activation of JNK, reduced expression of PTEN and increased phosphorylation of Akt compared with livers of wild-type mice. Hepatic infiltration of Th17 cells is critical for NASH initiation and development of fibrosis in mice, and reflects an infiltration of Th22 cells. Th22 cells are protective in NASH, but only in the absence of IL-17. These data strongly support the potentiality of clinical applications of IL-17 inhibitors that can prevent NASH by both abolishing the lipotoxic action of IL-17 and allowing IL-22-mediated protection.

Obstructive Sleep Apnea Is Associated with Nonalcoholic Steatohepatitis and Advanced Liver Histology

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) are growing in prevalence in the USA. Existing data on the relationship between OSA and NAFLD are conflicting and limited by the use of various histologic definitions of nonalcoholic steatohepatitis (NASH). Using a robust definition of NASH in a large, well-characterized cohort, we sought to evaluate whether OSA was associated with NASH and advanced fibrosis.

METHODS

Two hundred and thirteen subjects undergoing weight loss surgery were queried for OSA and then underwent liver biopsy. NASH was defined, as recommended by the American Association for the Study of Liver Disease, by the presence of all of the following: >5 % macrovesicular steatosis, lobular inflammation, and hepatocyte ballooning. NAFLD activity score (NAS) was also determined for each subject.

RESULTS

Subjects with OSA had significantly higher alanine and aspartate aminotransferase levels than subjects without OSA (ALT 54.1 vs. 37.7 U/L, P = 0.0007; AST 31.7 vs. 20.5 U/L, P = 0.0007). OSA was associated with the presence of NASH, and this remained significant after adjusting for age, gender, race, and diabetes mellitus (P = 0.03 OR 2.01; 95 %, 1.05-3.87). Steatosis grade, lobular inflammation grade, NAS score, and fibrosis stage were all significantly associated with the presence of OSA and remained so after adjustment.

CONCLUSIONS

OSA is associated with elevated aminotransferase levels, the presence of NASH, and advanced NASH histology. Further studies are needed to evaluate the impact of OSA treatment on NASH.

Declining liver graft quality threatens the future of liver transplantation in the United States

National liver transplantation (LT) volume has declined since 2006, in part because of worsening donor organ quality. Trends that degrade organ quality are expected to continue over the next 2 decades. We used the United Network for Organ Sharing (UNOS) database to inform a 20-year discrete event simulation estimating LT volume from 2010 to 2030. Data to inform the model were obtained from deceased organ donors between 2000 and 2009. If donor liver utilization practices remain constant, utilization will fall from 78% to 44% by 2030, resulting in 2230 fewer LTs. If transplant centers increase their risk tolerance for marginal grafts, utilization would decrease to 48%. The institution of "opt-out" organ donation policies to increase the donor pool would still result in 1380 to 1866 fewer transplants. Ex vivo perfusion techniques that increase the use of marginal donor livers may stabilize LT volume. Otherwise, the number of LTs in the United States will decrease substantially over the next 15 years. In conclusion, the transplant community will need to accept inferior grafts and potentially worse posttransplant outcomes and/or develop new strategies for increasing organ donation and utilization in order to maintain the number of LTs at the current level.

Management of dyslipidemia as a cardiovascular risk factor in individuals with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most frequent cause of liver disease in the United States and is associated with an increased risk of cardiovascular disease (CVD) and cardiovascular (CV) mortality, independent of traditional cardiovascular risk factors. CVD is one of the most common causes of death among individuals with NAFLD and management of NAFLD must extend beyond liver disease to include CVD risk modification. Clinicians should assess CVD risk with the Framingham Risk Score and screen for CVD risk factors including dyslipidemia, diabetes mellitus, hypertension, tobacco use, and the metabolic syndrome. CVD risk factors, particularly dyslipidemia, require aggressive medical management to reduce the high risk of CVD events and death in individuals with NAFLD.

The role of diet on intestinal microbiota metabolism: downstream impacts on host immune function and health, and therapeutic implications

Dietary impacts on health may be one of the oldest concepts in medicine; however, only in recent years have technical advances in mass spectroscopy, gnotobiology, and bacterial sequencing enabled our understanding of human physiology to progress to the point where we can begin to understand how individual dietary components can affect specific illnesses. This review explores the current understanding of the complex interplay between dietary factors and the host microbiome, concentrating on the downstream implications on host immune function and the pathogenesis of disease. We discuss the influence of the gut microbiome on body habitus and explore the primary and secondary effects of diet on enteric microbial community structure. We address the impact of consumption of non-digestible polysaccharides (prebiotics and fiber), choline, carnitine, iron, and fats on host health as mediated by the enteric microbiome. Disease processes emphasized include non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, IBD, and cardiovascular disease/atherosclerosis. The concepts presented in this review have important clinical implications, although more work needs to be done to develop fully and validate potential therapeutic approaches. Specific dietary interventions offer exciting potential for nontoxic, physiologic ways to alter enteric microbial structure and metabolism to benefit the natural history of many intestinal and systemic disorders.

Risk profile of hepatocellular carcinoma reveals dichotomy among US veterans

BACKGROUND

Hepatocellular carcinoma (HCC) is traditionally associated with chronic liver injury resulting from hepatitis B virus (HBV) and hepatitis C virus (HCV) infection or excessive consumption of alcohol. In addition, recent evidence links HCC to diabetes.

AIMS

Since these risk factors are prevalent among US veterans, we analyzedcontribution of various etiologies toHCC incidence in this population.

METHODS

Clinicopathological correlates of 150 male US veterans diagnosed with HCC between 2001 and 2010 were analyzed and compared to frequency-matched (2:1) non-cancer controls in a single center.

RESULTS

HCC was associated with cirrhosis (odds ratio [OR], 250.84; 95 % confidence interval [CI], 86.92-723.88; p < 0.0001), chronic hepatitis B (OR, 34.30 95 % CI, 1.97-598.47; p = 0.015), chronic hepatitis C (OR, 6.84; 95 % CI, 3.89-12.04; p < 0.0001), alcohol use (OR, 6.76; 95 % CI, 4.35-10.52; p < 0.0001), and smoking (OR, 1.83; 95 % CI, 1.23-2.89; p = 0.009), but surprisingly not with diabetes. Only in a subgroup of HCC patients with no "traditional" risk factors did diabetes become a strong independent predictor of HCC when compared to HCC patients with at least one such risk factor (OR, 10.69; 95 % CI, 1.88-60.63, p = 0.007). This subgroup was further distinguished by older age, increased prevalence of hypertension, nonsmoking, and a trend to develop noncirrhotic HCC.

CONCLUSIONS

While HCC in US veterans is overwhelmingly linked to cirrhosis due to "traditional" risk factors, it also occurs with a separate clinical profile characterized by diabetes and no evidence of cirrhosis, suggesting distinct mechanisms of hepatocarcinogenesis and needs for surveillance.

Obesity and liver disease: the epidemic of the twenty-first century

Obesity is a rapidly growing health problem that is associated with more than 65 comorbidities and results in substantially increased all-cause mortality. The increase of obesity has played an important role in the increasing prevalence of nonalcoholic fatty liver disease (NAFLD), the most common cause of liver disease in the United States. Understanding the prevalence, comorbidities, and pathogenesis of obesity provides an essential foundation for clinicians who care for individuals with NAFLD.

Hepatocellular Carcinoma in Non-alcoholic Fatty Liver Disease: Epidemiology, Pathogenesis, and Prevention

Hepatocellular cancer (HCC) is the fifth most prevalent cancer worldwide and the third leading cause of cancer-related deaths. Non-alcoholic fatty liver disease (NAFLD), a spectrum of hepatic disorders associated with obesity and the metabolic syndrome, is a recognized risk factor for HCC. NAFLD that is advanced to cirrhosis carries the highest risk for HCC, but there is increasing concern that NAFLD-associated HCC may also occur in non-cirrhotic liver. As NAFLD is rapidly becoming the most common liver condition, it has been implicated in the worrisome trend of rising HCC incidence in a number of countries, which may offset successful measures in reducing the effect of virus-related liver cancer. Independently or in synergy with cirrhosis, NAFLD may provide a special oncogenic microenvironment through its pathogenic association with chronic nutrient excess and adipose tissue remodeling, characterized by pro-inflammatory adipokine profiles, lipotoxicity, altered hepatocellular bioenergetics, and insulin resistance. Better understanding of this complex process, and development of reliable biomarkers for HCC will be critical for early recognition and risk prediction. Moreover, correcting deranged lipid metabolism and restoring insulin sensitivity by lifestyle measures and targeted pharmacotherapy holds major promise for effective prevention of NAFLD-associated HCC.

Role of the intestinal microbiome in liver disease

The liver integrates metabolic outcomes with nutrient intake while preventing harmful signals derived from the gut to spread throughout the body. Direct blood influx from the gastrointestinal tract through the portal vein makes the liver a critical firewall equipped with a broad array of immune cells and innate immune receptors that recognize microbial-derived products, microorganisms, toxins and food antigens that have breached the intestinal barrier. An overwhelming amount of evidence obtained in the last decade indicates that the intestinal microbiota is a key component of a wide variety of physiological processes, and alterations in the delicate balance that represents the intestinal bacterial communities are now considered important determinants of metabolic syndrome and immunopathologies. Moreover, it is now evident that the interaction between the innate immune system and the intestinal microbiota during obesity or autoimmunity promotes chronic liver disease progression and therefore it might lead to novel and individualized therapeutic approaches. In this review, we discuss a growing body of evidence that highlights the central relationship between the immune system, the microbiome, and chronic liver disease initiation and progression.

The absence of obstructive sleep apnea may protect against non-alcoholic fatty liver in patients undergoing bariatric surgery

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide and its progressive form, steatohepatitis, will be the leading indication for liver transplant by 2020. While risk factors for steatohepatitis have been identified, little work has been performed to identify factors protective against NAFLD development.

Aim

This study sought to identify factors predictive of normal liver histology in a bariatric cohort.

Methods

Patients undergoing weight loss surgery with liver biopsies at the time of surgery were included. Patients with other causes of chronic liver disease were excluded.

Results

One hundred fifty-nine patients were included. Forty-nine patients had normal liver histology and 110 patients had NAFLD. Several previously identified factors associated with normal liver histology were found. Black race was the strongest predictor of the absence of NAFLD with an odds ratio (OR) of 6.8, 95% confidence interval (CI) 2.4–18.9. Low HOMA-IR was also associated with normal histology (OR 1.4, 95% CI 1.03–1.9). In contrast, low HDL was associated with a decreased chance of normal histology (OR 0.38, 95% CI 0.05–0.83). Interestingly, a novel protective factor, the absence of obstructive sleep apnea (OSA) was strongly associated with normal histology (OR 5.6, 95% CI 2.0–16.1). In multivariate regression controlling for BMI, black race, absence of OSA, low HOMA-IR and low ALT independently predicted normal liver histology with an area under the ROC curve of 0.85.

Conclusions

Our study confirmed several factors associated with normal liver histology, including black race and identified a novel factor, absence of OSA. Further evaluation of these factors will allow for improved understanding of the pathogenesis of NAFLD.

Sonographic hepatorenal ratio: a noninvasive method to diagnose nonalcoholic steatosis

PURPOSE

To evaluate the accuracy of the sonographic hepatorenal ratio (HRR) in the diagnosis and grading of nonalcoholic steatosis, using biopsy as the reference.

METHODS

Ultrasound (US) and liver biopsy were performed in 42 patients with nonalcoholic fatty liver disease. Forty healthy volunteers without steatosis at US and without risk factors for nonalcoholic fatty liver disease were also studied. The HRR was obtained by dividing the mean brightness level of region-of-interest pixels in hepatic parenchyma by that in renal parenchyma. Needle biopsy samples (hematoxylin-eosin stained) were classified as mild (5-33% fatty infiltration), moderate (>33-66%), or severe (>66%) steatosis. Spearman coefficient was used to evaluate the correlation between HRR and steatosis grade, analysis of variance for differences between subgroups, and receiver operating characteristic curve analysis for sensitivity and specificity.

RESULTS

Significant correlation was found between HRR and histologic steatosis (r = 0.80, p < 0.01). The HRR cutoff for predicting steatosis was ≥1.24 (sensitivity, 92.7%; specificity, 92.5%). The mean ± SD HRRs in controls and steatosis subgroups were control 1.09 ± 0.13, mild 1.46 ± 0.24, moderate 1.52 ± 0.27, severe 2.04 ± 0.3 and were significantly different from each other except between mild and moderate steatosis subgroups.

CONCLUSIONS

The HRR is a noninvasive, objective, and simple method that could be used to diagnose and grade hepatic steatosis.

The intestinal microbiota in chronic liver disease

Recent evidence indicates that the intestinal microflora plays a critical role in physiological and pathological processes; in particular, it is now considered a key determinant of immune pathologies and metabolic syndrome. Receiving the majority of its blood supply from the portal vein, the liver represents the first line of defense against food antigens, toxins, microbial-derived products, and microorganisms. Moreover, the liver is critically positioned to integrate metabolic outcomes with nutrient intake. To accomplish this function, the liver is equipped with a broad array of immune networks. It is now evident that, during pathological processes associated with obesity, alcohol-intake, or autoimmunity, the interaction between these immune cell populations and the intestinal microbiota promotes chronic liver disease progression and therefore they represent a novel therapeutic target. Herein, we highlight recent studies that have shed new light on the relationship between the microbiome, the innate immune system, and chronic liver disease progression.

Development of poly(vinyl acetate-methylacrylic acid)/chitosan/Fe3O4 nanoparticles for the diagnosis of non-alcoholic steatohepatitis with magnetic resonance imaging

Non-alcoholic steatohepatitis is a burgeoning health problem. To diagnose NASH with magnetic resonance imaging (MRI), an effective contrast agent, a stable suspension of superparamagnetic Fe(3)O(4) nanoparticles, were newly developed. The negatively charged Fe(3)O(4) nanoparticles were coated with positive chitosan (CS) firstly, and then assembled with poly(vinyl acetate-methylacrylic acid) (P(VAc-MAA)). Transmission electron microscope and dynamic light scattering confirmed that the obtained P(VAc-MAA)/CS/Fe(3)O(4) nanoparticles had a spherical or ellipsoidal morphology with an average diameter in the range of 14-20 nm. The superparamagnetic property and spinel structure of the Fe(3)O(4) nanoparticles were well preserved due to the protection of the P(VAc-MAA)/CS layers on the surface of the Fe(3)O(4) nanoparticles. The in vivo rat experiments confirmed that the P(VAc-MAA)/CS/Fe(3)O(4) nanoparticles were an effective contrast agent for MRI to diagnose NASH.

Hepatocellular carcinoma in non-alcoholic fatty liver disease: an emerging menace

Hepatocellular carcinoma (HCC) is a common cancer worldwide that primarily develops in cirrhosis resulting from chronic infection by hepatitis B virus and hepatitis C virus, alcoholic injury, and to a lesser extent from genetically determined disorders such as hemochromatosis. HCC has recently been linked to non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of obesity and related metabolic disorders such as diabetes. This association is alarming due to the globally high prevalence of these conditions and may contribute to the rising incidence of HCC witnessed in many industrialized countries. There is also evidence that NAFLD acts synergistically with other risk factors of HCC such as chronic hepatitis C and alcoholic liver injury. Moreover, HCC may complicate non-cirrhotic NAFLD with mild or absent fibrosis, greatly expanding the population potentially at higher risk. Major systemic and liver-specific molecular mechanisms involved include insulin resistance and hyperinsulinemia, increased TNF signaling pathways, and alterations in cellular lipid metabolism. These provide new targets for prevention, early recognition, and effective treatment of HCC associated with NAFLD. Indeed, both metformin and PPAR gamma agonists have been associated with lower risk and improved prognosis of HCC. This review summarizes current evidence as it pertains to the epidemiology, pathogenesis, and prevention of NAFLD-associated HCC.

Inflammasome-mediated dysbiosis regulates progression of NAFLD and obesity

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and the leading cause of chronic liver disease in the Western world. Twenty per cent of NAFLD individuals develop chronic hepatic inflammation (non-alcoholic steatohepatitis, NASH) associated with cirrhosis, portal hypertension and hepatocellular carcinoma, yet the causes of progression from NAFLD to NASH remain obscure. Here, we show that the NLRP6 and NLRP3 inflammasomes and the effector protein IL-18 negatively regulate NAFLD/NASH progression, as well as multiple aspects of metabolic syndrome via modulation of the gut microbiota. Different mouse models reveal that inflammasome-deficiency-associated changes in the configuration of the gut microbiota are associated with exacerbated hepatic steatosis and inflammation through influx of TLR4 and TLR9 agonists into the portal circulation, leading to enhanced hepatic tumour-necrosis factor (TNF)-α expression that drives NASH progression. Furthermore, co-housing of inflammasome-deficient mice with wild-type mice results in exacerbation of hepatic steatosis and obesity. Thus, altered interactions between the gut microbiota and the host, produced by defective NLRP3 and NLRP6 inflammasome sensing, may govern the rate of progression of multiple metabolic syndrome-associated abnormalities, highlighting the central role of the microbiota in the pathogenesis of heretofore seemingly unrelated systemic auto-inflammatory and metabolic disorders.

Editorial: hepatocellular carcinoma in type 2 diabetes: more than meets the eye

Hepatocellular carcinoma (HCC), a disease with poor survival rates unless recognized and treated early, ranks as the fifth most common cancer worldwide and has a rising incidence in the United States. Recent data indicate that the growing epidemic of type 2 diabetes mellitus may contribute to this alarming trend. In this issue, Lai et al. utilize a large Taiwanese insurance claims database to demonstrate that diabetes is associated with an increased risk of HCC. Moreover, this risk escalates if diabetes coincides with chronic hepatitis C and cirrhosis. Lai et al. also show that treatment with metformin or thiazolidinediones may reduce the risk of HCC. The findings may prompt risk stratification for HCC surveillance and improved disease control in diabetes as measures of cancer prevention.

Genetic factors associated with the presence and progression of nonalcoholic fatty liver disease: a narrative review

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Whereas insulin resistance and obesity are considered major risk factors for the development and progression of NAFLD, the genetic underpinnings are unclear. Before 2008, candidate gene studies based on prior knowledge of pathophysiology of fatty liver yielded conflicting results. In 2008, Romeo et al. published the first genome wide association study and reported the strongest genetic signal for the presence of fatty liver (PNPLA3, patatin-like phospholipase domain containing 3; rs738409). Since then, two additional genome wide scans were published and identified 9 additional genetic variants. Whereas these results shed light into the understanding of the genetics of NAFLD, most of associations have not been replicated in independent samples and, therefore, remain undetermined the significance of these findings. This review aims to summarize the understanding of genetic epidemiology of NAFLD and highlights the gaps in knowledge.

The steatohepatitic variant of hepatocellular carcinoma and its association with underlying steatohepatitis

Steatohepatitis and metabolic syndrome are increasingly recognized as important risk factors for development of hepatocellular carcinoma. We have recently described a histologic subtype of hepatocellular carcinoma termed steatohepatitic hepatocellular carcinoma, which shows features resembling steatohepatitis in the nonneoplastic liver. The present study is undertaken to assess the association between the steatohepatitic hepatocellular carcinoma variant and underlying steatohepatitis and features of metabolic syndrome. We examined all hepatocellular carcinomas diagnosed on resections and explant specimens over a 3.5-year period at our institution. Tumors were classified as either conventional hepatocellular carcinoma or steatohepatitic hepatocellular carcinoma variant based on their predominant histopathologic pattern. The underlying chronic liver disease in each case was determined. The steatohepatitic hepatocellular carcinoma variant represented 13.5% (16/118) of cases. All but one case of steatohepatitic hepatocellular carcinoma occurred in patients with underlying steatohepatitis. Steatohepatitic hepatocellular carcinoma was diagnosed in 35.7% of patients with either nonalcoholic steatohepatitis or alcoholic liver disease compared with 1.3% of patient with other chronic liver diseases (P < .0001). The steatohepatitic hepatocellular carcinoma group had a significantly higher number of metabolic syndrome risk factors (2.44 versus 1.48, P = .01) and a higher percentage of patients with at least 3 metabolic syndrome components (50% versus 22.5%, P = .02). Immunohistochemically, there were diffuse loss of cytoplasmic CK8/18 and increased numbers of activated hepatic stellate cells within steatohepatitic hepatocellular carcinoma, in a pattern identical to that seen in steatohepatitis in nonneoplastic liver. Hepatocellular carcinomas showing a "steatohepatitic" histologic phenotype are strongly associated with underlying steatohepatitis and metabolic syndrome. This association further supports a possible role of steatohepatitis in human hepatocarcinogenesis.

Diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver: a meta-analysis

Ultrasonography is a widely accessible imaging technique for the detection of fatty liver, but the reported accuracy and reliability have been inconsistent across studies. We aimed to perform a systematic review and meta-analysis of the diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver. We used MEDLINE and Embase from October 1967 to March 2010. Studies that provided cross-tabulations of ultrasonography versus histology or standard imaging techniques, or that provided reliability data for ultrasonography, were included. Study variables were independently abstracted by three reviewers and double checked by one reviewer. Forty-nine (4720 participants) studies were included for the meta-analysis of diagnostic accuracy. The overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of ultrasound for the detection of moderate-severe fatty liver, compared to histology (gold standard), were 84.8% (95% confidence interval: 79.5-88.9), 93.6% (87.2-97.0), 13.3 (6.4-27.6), and 0.16 (0.12-0.22), respectively. The area under the summary receiving operating characteristics curve was 0.93 (0.91-0.95). Reliability of ultrasound for the detection of fatty liver showed kappa statistics ranging from 0.54 to 0.92 for intrarater reliability and from 0.44 to 1.00 for interrater reliability. Sensitivity and specificity of ultrasound was similar to that of other imaging techniques (i.e., computed tomography or magnetic resonance imaging). Statistical heterogeneity was present even after stratification for multiple clinically relevant characteristics.

CONCLUSION

Ultrasonography allows for reliable and accurate detection of moderate-severe fatty liver, compared to histology. Because of its low cost, safety, and accessibility, ultrasound is likely the imaging technique of choice for screening for fatty liver in clinical and population settings.

The influence of nonalcoholic fatty liver disease and its associated comorbidities on liver transplant outcomes

GOALS

To define the influence of nonalcoholic fatty liver disease (NAFLD) and its associated comorbidities on liver transplant outcomes.

BACKGROUND

NAFLD cirrhosis is an increasing indication for transplant. The transplant outcomes of NAFLD patients with metabolic syndrome comorbidities remain unclear.

STUDY

We examined a single center, retrospective cohort between 2004 and 2007 to determine transplant mortality for NAFLD and non-NAFLD patients accounting for the possible independent effects of diabetes, hypertension, obesity, and hyperlipidemia. The primary outcomes were 30-day, 1-year, and 3-year all-cause mortality. Cox proportional hazard ratios were determined controlling for various recipient and donor covariates.

RESULTS

In our study, of 118 liver transplants, 18% were performed for NAFLD cirrhosis. Adjusted hazard ratios for death for NAFLD compared with non-NAFLD patients at 30 days, 1 year, and 3 years were 8.96 (1.06, 75.8), 1.49 (0.38, 5.81), and 1.05 (0.29, 3.78), respectively. Compared with nondiabetic patients, diabetic patients had hazard ratios at 30 days, 1 year, and 3 years of 2.02 (0.31, 12.9), 2.82 (0.94, 8.47), 3.58 (1.32, 9.71), respectively. Obesity, hypertension, and hyperlipidemia did not have a significant impact on posttransplant mortality.

CONCLUSIONS

We conclude that NAFLD increases 30-day transplant mortality whereas diabetes increases 3-year mortality. Future work should determine the strategies to decrease perioperative mortality among NAFLD patients and ways to improve long-term transplant survival among diabetics.

Non-alcoholic steatohepatitis and influence of age and gender on histopathologic findings

AIM: To characterize the histopathologic specifications of non-alcoholic steatohepatitis (NASH) according to age and gender.

METHODS: An analytical cross-sectional study was conducted in two private gastroenterology clinics on biopsy proven patients suffering from NASH. Biopsy histopathologic findings as well as demographic and laboratory data of the patients at the time of biopsy were gathered retrospectively from clinical records. The grading and staging of histopathologic findings were performed according to the Brunt method after reevaluation of the slides by a pathologist. Patients were divided into two groups according to age (below and above 55 years). Mean quantitative grade of all pathologic findings were also calculated according to Brunt scoring values.

RESULTS: A total number of 77 NASH patients, consisting of 58 males (75.3%) and 19 (24.7%) females with a mean age of 41.99 ± 11.80 years (range, 18-70 years), were enrolled. The mean age (48.72 ± 13.99 years vs 39.74 ± 10.16 years, P = 0.004) and aspartate aminotransferase level (75.11 ± 29.68 U/L vs 52.78 ± 25.00 U/L, P = 0.002) was significantly higher in female patients. Mean quantitative grade of hepatosteatosis was significantly higher in females (2.00 ± 0.82 vs 1.59 ± 0.68, P = 0.031) compared to males. Fifty four percent (34/65) of young patients had mild hepatosteatosis (Grade I) while only one patient (11.2%) in the older group had grade I hepatosteatosis. Patients aged ≥ 55 had significantly more severe hepatosteatosis (Grade III) (44.4% vs 9.5%, P = 0.007) and the mean quantitative grade of hepatosteatosis was significantly higher among them (2.33 ± 0.71 vs 1.56 ± 0.67, P = 0.002). Multivariate analysis after omitting the confounding role of age revealed a higher grade of hepatosteatosis in female patients (P = 0.010).

CONCLUSION: These findings point toward the possible influence of age in the severity of steatohepatitis, portal and lobar inflammation in patients suffering from NASH while gender independently might contribute to the level of steatohepatitis.

A fresh look at NASH pathogenesis. Part 1: the metabolic movers

The strong relationship between over-nutrition, central obesity, insulin resistance/metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) suggest pathogenic interactions, but key questions remain. NAFLD starts with over-nutrition, imbalance between energy input and output for which the roles of genetic predisposition and environmental factors (diet, physical activity) are being redefined. Regulation of energy balance operates at both central nervous system and peripheral sites, including adipose and liver. For example, the endocannabinoid system could potentially be modulated to provide effective pharmacotherapy of NAFLD. The more profound the metabolic abnormalities complicating over-nutrition (glucose intolerance, hypoadiponectinemia, metabolic syndrome), the more likely is NAFLD to take on its progressive guise of non-alcoholic steatohepatitis (NASH). Interactions between steatosis and insulin resistance, visceral adipose expansion and subcutaneous adipose failure (with insulin resistance, inflammation and hypoadiponectinemia) trigger amplifying mechanisms for liver disease. Thus, transition from simple steatosis to NASH could be explained by unmitigated hepatic lipid partitioning with failure of local adaptive mechanisms leading to lipotoxicity. In part one of this review, we discuss newer concepts of appetite and metabolic regulation, bodily lipid distribution, hepatic lipid turnover, insulin resistance and adipose failure affecting adiponectin secretion. We review evidence that NASH only occurs when over-nutrition is complicated by insulin resistance and a highly disordered metabolic milieu, the same 'metabolic movers' that promote type 2 diabetes and atheromatous cardiovascular disease. The net effect is accumulation of lipid molecules in the liver. Which lipids and how they cause injury, inflammation and fibrosis will be discussed in part two.

The liver and the waistline: Fifty years of growth

Fifty years of the Gastroenterological Society of Australia have witnessed the changing appearance of Australians. Asian immigration has transformed the dominant urban culture from European to Eurasian, with some unique Australian attributes. Meanwhile, global conditions have altered body shape, and our sports-proud country is now fat! Thus, as in North America, Europe, China, and affluent Asia-Pacific countries, prosperity and lifestyle, cheap processed foods coupled with reduced physical activity have created an epidemic of over-nutrition resulting in overweight/obesity. Additional genetic factors are at the core of the apple shape (central obesity) that typifies over-nourished persons with metabolic syndrome. Indigenous Australians, once the leanest and fittest humans, now have exceedingly high rates of obesity and type 2 diabetes, contributing to shorter life expectancy; Asian Australians are also at higher risk. Like non-steroidal anti-inflammatory drugs (NSAIDs) and cigarette smoking, obesity now contributes much to gastrointestinal morbidity and mortality (gastroesophageal reflux disease, cancers, gallstones, endoscopy complications). This review focuses on Australian research about fatty liver, particularly roles of central obesity/insulin resistance in non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH). The outputs include many highly cited original articles and reviews and the first book on NAFLD. Studies have identified community prevalence, clinical outcomes, association with insulin resistance, metabolic syndrome and hypoadiponectinemia, developed and explored animal models for mechanisms of inflammation and fibrosis, conceptualized etiopathogenesis, and demonstrated that NASH can be reversed by lowering body weight and increasing physical activity. The findings have led to development of regional guidelines on NAFLD, the first internationally, and should now inform daily practice of gastroenterologists.

Systematic review of risk factors for fibrosis progression in non-alcoholic steatohepatitis

BACKGROUND/AIMS

Non-alcoholic steatohepatitis (NASH) is a growing public health problem. Evaluation of risk factors for fibrosis in NASH will help to target resources to reduce development of cirrhosis. This study had two aims; the first to compile longitudinal histological data to characterize the natural history of fibrosis progression in NASH, and second, to identify predictive factors for progression to advanced fibrosis (stage 3 or greater) in NASH.

METHODS

Subjects had to have a histological diagnosis compatible with NASH on their initial biopsy, received no intervention of proven histological benefit, and undergone two liver biopsies with at least an interval of one year between them.

RESULTS

Ten studies were selected comprising 221 patients. 37.6% had progressive fibrosis over a mean follow-up interval of 5.3 years (SD, 4.2 years, median, 3.7 years, range 1.0-21.3 years). Proportional hazards regression analysis demonstrated that age (HR=0.98, p=0.009) and inflammation on initial biopsy (any inflammation, HR=2.5, p=0.001; grade 1, HR=2.5, p=0.001; grade 2, HR=2.4, p=0.003) are independent predictors of progression to advanced fibrosis. Other traditional parameters (e.g. obesity, diabetes, hypertension) were not statistically significant predictors.

CONCLUSIONS

Presence of inflammation on the initial biopsy and age are independent predictors of progression to advanced fibrosis in patients with NASH.

Trends in nonalcoholic fatty liver disease-related hospitalizations in US children, adolescents, and young adults

OBJECTIVE

To investigate temporal trends of nonalcoholic fatty liver disease (NAFLD) and obesity among hospitalized US children, adolescents, and young adults over the past 2 decades and to examine potential sex disparities in NAFLD hospitalizations.

METHODS

Hospitalization discharges with NAFLD or obesity were identified among children and young adults (6-25 years, weighted n = 91,687,413) from the 1986 to 2006 National Hospital Discharge Survey data. Age- and sex-specific rates and trends in hospitalizations with NAFLD and obesity were estimated. Rates were standardized to age distribution of the 2000 US Census population. Sex disparities were examined for the most recent period 2004 to 2006 (weighted n = 12,969,532).

RESULTS

Between 1986 to 1988 and 2004 to 2006, hospitalizations with NAFLD diagnosis increased from 0.9 to 4.3/100,000 population (P < 0.001). During the same time, hospitalizations with a diagnosis of obesity increased from 35.5 to 114.7/100,000 population (P < 0.001). During 2004 to 2006, hospitalization rates with a diagnosis of NAFLD were higher among females than among males (5.9 vs 2.7/100,000 population, P < 0.001), as were hospitalizations with a diagnosis of obesity (140.8 vs 61.5/100,000 population, P < 0.001). Obesity and diabetes were reported in 43.3% and 31.9%, respectively, of discharges with NAFLD.

CONCLUSION

The prevalence of NAFLD among young hospitalized patients increased in the past 2 decades, paralleling obesity-related hospitalizations. This could be a consequence of the obesity epidemic or of increased screening for liver disease.