Association of per- and polyfluoroalkyl substance exposure with fatty liver disease risk in US adults

Background & Aims

Per- and polyfluoroalkyl substances (PFAS) are widespread pollutants with demonstrated hepatotoxicity. Few studies have examined the association between PFAS and fatty liver disease (FLD) risk in an adult population.

Methods

In this cross-sectional study of participants from the 2017–2018 National Health and Nutrition Examination Survey, serum PFAS were measured, and FLD cases were ascertained by vibration-controlled transient elastography. Logistic regression models were used to examine the association between circulating PFAS levels and FLD risk. Analyses were stratified into non-alcoholic FLD and alcoholic FLD risk groups by alcohol intake status, as well as controlling for other risk factors, including personal demographics, lifestyle factors, and related health factors.

Results

Among 1,135 eligible participants, 446 had FLD. For FLD risk, the multivariable-adjusted odds ratio per log-transformed SD increase (OR_SD) in perfluorohexane sulfonate (PFHxS) was 1.13 (95% CI 1.01–1.26). The association between PFHxS and FLD appeared stronger among individuals with obesity or high-fat diets (both pinteraction <0.05). When limiting the analysis to 212 heavy drinkers (≥2 drinks/day for women and ≥3 drinks/day for men), significantly higher risk of alcoholic FLD was found for higher levels of perfluorooctanoic acid (OR_SD 1.79; 95% CI 1.07–2.99), PFHxS (OR_SD 2.06; 95% CI 1.17–3.65), and perfluoroheptane sulfonic acid (OR_SD 1.44; 95% CI 1.00–2.07), and marginally significant higher risk for total PFAS (OR_SD 2.12; 95% CI 0.99–4.54). In never or light drinkers, we did not observe any significant association between PFAS and non-alcoholic FLD. Significant positive associations were found for PFAS with aspartate aminotransferase, gamma-glutamyl transaminase, total bilirubin, and albumin (β ranged from 0.008 to 0.101, all p <0.05).

Conclusions

Higher serum PFAS was moderately associated with FLD risk and worse liver function in the general population, and among those with independent risk factors, including heavy alcohol intake, obesity, or high-fat diets, PFAS increased the risk. These results suggest synergistic effects on hepatic steatosis between PFAS exposures as measured through biomonitoring data and lifestyle risk factors in a nationally representative US population.

Impact and Implications

The per- and polyfluoroalkyl substances (PFAS) may convey higher risk for chronic liver disease in humans. Among 1,135 US adults in the 2017–2018 National Health and Nutrition Examination Survey, we found that higher serum PFAS was associated with higher fatty liver disease risk and worse liver function, especially among those with liver disease risk factors, including heavy alcohol intake, obesity, or high-fat diets. Continuously monitoring PFAS in the population and examining how they potentiate risk to the liver are essential.

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PFAS may convey higher risk for chronic liver disease in humans.

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We found that higher serum PFAS was associated with higher fatty liver disease risk and worse liver function.

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This was especially evident in those with liver disease risk factors, including heavy alcohol intake, obesity, or high-fat diets.

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Continuously monitoring PFAS in the population and examining how they potentiate risk to the liver are essential.

The Development of an Infrastructure to Facilitate the Use of Whole Genome Sequencing for Population Health

The clinical use of genomic analysis has expanded rapidly resulting in an increased availability and utility of genomic information in clinical care. We have developed an infrastructure utilizing informatics tools and clinical processes to facilitate the use of whole genome sequencing data for population health management across the healthcare system. Our resulting framework scaled well to multiple clinical domains in both pediatric and adult care, although there were domain specific challenges that arose. Our infrastructure was complementary to existing clinical processes and well-received by care providers and patients. Informatics solutions were critical to the successful deployment and scaling of this program. Implementation of genomics at the scale of population health utilizes complicated technologies and processes that for many health systems are not supported by current information systems or in existing clinical workflows. To scale such a system requires a substantial clinical framework backed by informatics tools to facilitate the flow and management of data. Our work represents an early model that has been successful in scaling to 29 different genes with associated genetic conditions in four clinical domains. Work is ongoing to optimize informatics tools; and to identify best practices for translation to smaller healthcare systems.

Body mass index trajectories, weight gain and risks of liver and biliary tract cancers

BACKGROUND

Little is known about the role of early obesity or weight change during adulthood in the development of liver cancer and biliary tract cancer (BTC).

METHODS

We investigated the associations of body mass index (BMI) and weight trajectories with the risk of liver cancer and BTC in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO). BMI was self-reported at ages 20, 50, and at enrollment. BMI trajectories were determined using latent class growth models. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 15.9 years among 138,922 participants, 170 liver cancer and 143 BTC cases were identified. Compared with those whose BMI does not exceed 25 kg/m2, participants with BMI exceeding 25 kg/m2 at age 20 had increased risks of liver cancer (HR = 2.03, 95% CI: 1.26-3.28) and BTC (HR = 1.99, 95% CI: 1.16-3.39). Compared to participants maintaining normal BMI until enrollment, trajectory of normal weight at age 20 to obesity at enrollment was associated with increased risk for liver cancer (HR = 2.50, 95% CI: 1.55-4.04) and BTC (HR = 1.83, 95% CI: 1.03-3.22). Compared to adults with stable weight (+/-5kg) between age 20 to 50 years, weight gain ≥20 kg between ages 20 to 50 years had higher HRs of 2.24 (95%CI: 1.40-3.58) for liver cancer and 1.86 (95% CI: 1.12-3.09) for BTC.

CONCLUSIONS

Being overweight/obese at age 20, and BMI trajectories that result in being overweight and/or obese, may increase risk for both liver cancer and BTC.

A Dynamic Aspartate-to-Alanine Aminotransferase Ratio Provides Valid Predictions of Incident Severe Liver Disease

The aspartate-to-alanine aminotransferase ratio (AAR) is associated with liver fibrosis, but its predictive performance is suboptimal. We hypothesized that the association between AAR and liver disease depends on absolute transaminase levels and developed and validated a model to predict liver-related outcomes in the general population. A Cox regression model based on age, AAR, and alanine aminotransferase (ALT) level (dynamic AAR [dAAR]) using restricted cubic splines was developed in Finnish population-based health-examination surveys (FINRISK, 2002-2012; n = 18,067) with linked registry data for incident liver-related hospitalizations, hepatocellular carcinoma, or liver death. The model was externally validated for liver-related outcomes in a Swedish population cohort (Swedish Apolipoprotein Mortality Risk [AMORIS] subcohort; n = 126,941) and for predicting outcomes and/or prevalent fibrosis/cirrhosis in biopsied patients with nonalcoholic fatty liver disease (NAFLD), chronic hepatitis C, or alcohol-related liver disease (ALD). The dynamic AAR model predicted liver-related outcomes both overall (optimism-corrected C-statistic, 0.81) and in subgroup analyses of the FINRISK cohort and identified persons with >10% risk for liver-related outcomes within 10 years. In independent cohorts, the C-statistic for predicting liver-related outcomes up to a 10-year follow-up was 0.72 in the AMORIS cohort, 0.81 in NAFLD, and 0.75 in ALD. Area-under-the-curve (AUC) for detecting prevalent cirrhosis was 0.80-0.83 in NAFLD, 0.80 in hepatitis C, but only 0.71 in ALD. In ALD, model performance improved when using aspartate aminotransferase instead of ALT in the model (C-statistic, 0.84 for outcome; AUC, 0.82 for prevalent cirrhosis). Conclusion: A dAAR score provides prospective predictions for the risk of incident severe liver outcomes in the general population and helps detect advanced liver fibrosis/cirrhosis. The dAAR score could potentially be used for screening the unselected general population and as a trigger for further liver evaluations.

Increased Posttransplant Mortality for Autoimmune Hepatitis Compared With Other Autoimmune Liver Diseases

GOALS

We sought to compare posttransplant outcomes between autoimmune liver disease.

BACKGROUND

Autoimmune liver diseases, namely primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH) generally have favorable posttransplant outcomes. PSC is known to require more retransplantation compared with PBC, however, comparisons to AIH are lacking. We sought to compare graft survival and the need for retransplant in AIH compared with other autoimmune liver disease.

STUDY

We compared posttransplant graft survival among the 3 entities using Cox regression and competing for risk analyses using the United Network for Organ Sharing (UNOS) database.

RESULTS

We found AIH is associated with significantly decreased graft survival compared with PBC [hazard ratio: 0.86; 95% confidence interval (CI): 0.77-0.96] and PSC (hazard ratio: 0.89; 95% CI: 0.8-0.99) after controlling for potential confounders. This is mainly driven by posttransplant death. On competing for risk analysis, AIH was associated with higher risk of death compared with PBC [subdistribution hazard ratio (SHR): 0.79; 95% CI: 0.7-0.89] and PSC (SHR: 0.72; 95% CI: 0.64-0.82) and lower risk of retransplant compared with PSC (SHR: 1.48; 95% CI: 1.19-1.8).

CONCLUSION

As prior studies have shown the similar risk of disease recurrence in AIH and PSC, our study indicates at least part of the increased posttransplant mortality in AIH may be due lower retransplantation rate in this population.

Treatment of Overlap Syndromes in Autoimmune Liver Disease: A Systematic Review and Meta-Analysis

The treatment of overlap syndromes is guided by small observational studies whose data have never been synthesized in a rigorous, quantitative manner. We conducted a systematic review and meta-analysis to evaluate the efficacy of available treatments for these rare and morbid conditions. We searched the literature for studies comparing ≥2 therapies for autoimmune hepatitis (AIH)-primary biliary cholangitis (PBC), AIH-primary sclerosing cholangitis (PSC), PBC-PSC, AIH-PBC-PSC, autoimmune cholangitis (AIC), or autoimmune sclerosing cholangitis (ASC) with respect to various clinical outcomes, including biochemical improvement and transplant-free survival. A total of 28 studies met the inclusion criteria for AIH-PBC, AIH-PSC, AIC, and ASC. AIH-PBC patients tended to experience more biochemical improvement with ursodeoxycholic acid (UDCA) + [corticosteroids and/or antimetabolites], i.e., "combination therapy", than with corticosteroids ± azathioprine (RR = 4.00, 95% CI 0.93-17.18). AIH-PBC patients had higher transplant-free survival with combination therapy than with UDCA, but only when studies with follow-up periods ≤90 months were excluded (RR = 6.50, 95% CI 1.47-28.83). Combination therapy may therefore be superior to both UDCA and corticosteroids ± azathioprine for the treatment of AIH-PBC, but additional studies are needed to show this definitively and to elucidate optimal treatments for other overlap syndromes.

The Pharmacologic Management of Osteoporosis in Primary Biliary Cholangitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Osteoporosis is a common complication of primary biliary cholangitis (PBC) yet evidence for effective therapy is lacking. We sought to review all randomized controlled trials evaluating pharmacotherapy against placebo or no intervention for treatment of osteoporosis in PBC.

METHODOLOGY

A comprehensive database search was conducted from inception through 29 March 2017. The primary outcome was incidence of fractures; secondary outcomes were change in bone mineral density (BMD) and adverse events. We assessed studies for risk of bias, graded quality of evidence, and used meta-analysis to obtain overall effect by pooling studies of the same drug class.

RESULTS

We identified 11 randomized controlled trials evaluating bisphosphonates (3), hormone replacement therapy (2), ursodeoxycholic acid (1), obeticholic acid (1), cyclosporin A (1), vitamin K (1), calcitriol (1), and sodium fluoride (1). No intervention significantly reduced fractures compared to control. Although significant improvement in BMD was seen in one study with alendronate, a third-generation bisphosphonate, no significant improvement was seen on pooled analysis of all bisphosphonates including first-generation bisphosphonates (standard mean difference 0.41, p = 0.68). On pooled analysis, hormone replacement therapy modestly improved lumbar BMD (standard mean difference 0.69, p = 0.02), but with significantly increased adverse events (odds ratio 8.82, p = 0.01).

CONCLUSIONS

There is a lack of high-quality evidence supporting the efficacy of any treatment of osteoporosis in PBC. This may be explained by lack of power in the included studies. However, our current understanding of PBC-related osteoporosis indicates that it results from decreased bone formation, which may explain the attenuated effect of traditional antiresorptive agents. Future studies should investigate newer anabolic bone agents.

Bone Health in Patients With Liver Diseases

Osteoporosis is the most common bone disease in chronic liver disease (CLD) resulting in frequent fractures and leading to significant morbidity in this population. In addition to patients with cirrhosis and chronic cholestasis, patients with CLD from other etiologies may be affected in the absence of cirrhosis. The mechanism of osteoporosis in CLD varies according to etiology, but in cirrhosis and cholestatic liver disease it is driven primarily by decreased bone formation, which differs from the increased bone resorption seen in postmenopausal osteoporosis. Direct toxic effects from iron and alcohol play a role in hemochromatosis and alcoholic liver disease, respectively. Chronic inflammation also has been proposed to mediate bone disease in viral hepatitis and nonalcoholic fatty liver disease. Treatment trials specific to osteoporosis in CLD are small, confined to primary biliary cholangitis and post-transplant patients, and have not consistently demonstrated a benefit in this population. As it stands, prevention of osteoporosis in CLD relies on the mitigation of risk factors such as smoking and alcohol use, treatment of underlying hypogonadism, and encouraging a healthy diet and weight-bearing exercise. The primary medical intervention for the treatment of osteoporosis in CLD remains bisphosphonates though a benefit in terms of fracture reduction has never been shown. This review outlines what is known regarding the pathogenesis of bone disease in CLD and summarizes current and emerging therapies.

Osteoporosis in Primary Biliary Cholangitis: Prevalence, Impact and Management Challenges

Primary biliary cholangitis (PBC) is a chronic, cholestatic condition associated with symptoms that directly impact the quality of life in those afflicted with the disease. In addition to pruritus and fatigue, patients with PBC may develop metabolic bone disease from reduced bone density, such as osteopenia and osteoporosis. Osteoporosis increases the risk of fractures, as well as morbidity and mortality. The prevalence of osteoporosis in PBC is expected to increase in conjunction with the rising prevalence of PBC as a whole. Timely diagnosis, prevention and management of osteoporosis are crucial in order to optimize the quality of life. There is a paucity of data evaluating the management of osteoporosis in PBC. The optimal timing for diagnosis and monitoring is not yet established and is guided by expert opinion. National guidelines recommend screening for osteoporosis at the time of diagnosis of PBC. Monitoring strategies are based on results of initial screening and individual risk factors for bone disease. Identifying reduced bone density is imperative to institute timely preventive and treatment strategies. However, treatment remains challenging as efficacious therapies are currently lacking. The data on treatment of osteoporosis in PBC are mostly extrapolated from postmenopausal osteoporosis literature. However, this data has not directly translated to useful treatment strategies for PBC-related osteoporosis, partly because of the different pathophysiological mechanisms of the two diseases. The lack of useful preventive measures and efficacious treatment strategies remains the largest pitfall that challenges the management of patients with PBC. In this review, we comprehensively outline the epidemiology, clinical implications and challenges, as well as management strategies of PBC-related osteoporosis.

Mortality on the UNOS Waitlist for Patients with Autoimmune Liver Disease

Background: Outcomes on the liver transplant waitlist can vary by etiology. Our aim is to investigate differences in waitlist mortality of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) using the United Network for Organ Sharing (UNOS) database. Methods: We identified patients who were listed for liver transplantation from 1987 to 2016 with a primary diagnosis of AIH, PBC, or PSC. We excluded patients with overlap syndromes, acute hepatic necrosis, missing data, and those who were children. The primary outcome was death or removal from the waitlist due to clinical deterioration. We compared waitlist survival using competing risk analysis. Results: Between 1987 and 2016, there were 7412 patients listed for liver transplant due to AIH, 8119 for PBC, and 10,901 for PSC. Patients with AIH were younger, more likely to be diabetic, and had higher listing model for end-stage liver disease (MELD) scores compared to PBC and PSC patients. Patients with PBC and AIH were more likely to be removed from the waitlist due to death or clinical deterioration. On competing risk analysis, AIH patients had a similar risk of being removed from the waitlist compared to those with PBC (subdistribution hazard ratio (SHR) 0.94, 95% CI 0.85–1.03) and higher risk of removal compared to those with PSC (SHR 0.8, 95% CI 0.72 to 0.89). Conclusion: Autoimmune hepatitis carries a similar risk of waitlist removal to PBC and a higher risk than PSC. The etiology of this disparity is not entirely clear and deserves further investigation.

Insulin Resistance and Genetic Risk Predict Liver-Related Outcomes and Death in Nonalcoholic Fatty Liver Disease

A pathophysiologic risk score consisting of insulin resistance and genetic risk predicts incident liver outcomes in NAFLD. Such scores may represent a viable strategy for risk stratification in NAFLD.

Hyperlipidaemia in primary biliary cholangitis: treatment, safety and efficacy

Primary biliary cholangitis (PBC) is an autoimmune liver disease associated with altered lipoprotein metabolism, mainly cholesterol. Hypercholesterolaemia, a major modifiable risk factor for cardiovascular disease in the general population, occurs in 75%-95% of individuals with PBC. The impact of hypercholesterolaemia on cardiovascular risk in PBC, however, is controversial. Previous data have shown that hypercholesterolaemia in PBC is not always associated with an increase in cardiovascular events. However, patients with PBC with cardiovascular risk factors may still warrant cholesterol-lowering therapy. Treatment of hypercholesterolaemia in PBC poses unique challenges among primary care providers due to concerns of hepatotoxicity associated with cholesterol-lowering medications. This review summarises the current understanding of the pathophysiology of hypercholesterolaemia in PBC and its pertinent cardiovascular risk. We will also discuss indications for treatment and the efficacy and safety of available agents for hypercholesterolaemia in PBC.

Treatment of Fatigue in Primary Biliary Cholangitis: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Fatigue is the most common complication of primary biliary cholangitis (PBC) and can be debilitating. Numerous interventions have been trialed targeting several proposed mechanisms of PBC-associated fatigue. We sought to summarize and perform a meta-analysis to determine the efficacy of these interventions.

METHODS

A comprehensive database search was conducted from inception through March 27, 2018. The primary outcome was proportion of fatigued patients or reduction in degree of fatigue. Adverse events were a secondary outcome. We assessed studies for risk of bias, graded quality of evidence, and used meta-analysis to obtain overall effect by pooling studies of the same class.

RESULTS

We identified 16 studies evaluating ursodeoxycholic acid (UDCA) (7), liver transplantation (2), serotonin reuptake inhibitors (2), colchicine (1), methotrexate (1), cyclosporine (1), modafinil (1), and obeticholic acid (1). On meta-analysis, UDCA was not associated with a reduction in risk of fatigue (RR = 0.86, 95% CI 0.69-1.08, p = 0.19, I² = 56.2%). While liver transplantation did reduce degree of fatigue (SMD - 0.57, 95% CI - 0.89 to - 0.24, p = 0.001, I² = 67.3%), fatigue did not return to baseline indicating the underlying cause may not be addressed.

CONCLUSIONS

While there is some improvement in fatigue with liver transplantation, there is a lack of high-quality evidence supporting the efficacy of any other intervention in the treatment of PBC-related fatigue. Further research into the underlying pathophysiology may help guide future trials.

Evidence of bias during liver transplant evaluation of non-alcoholic steatohepatitis cirrhosis patients

BACKGROUND & AIMS

Cardiovascular disease (CVD) is the leading cause of death among non-alcoholic steatohepatitis (NASH) patients and a major source of post-transplant mortality. We sought to examine the effect of comorbidities on listing for orthotopic liver transplant (OLT) in NASH patients.

METHODS

In this retrospective cohort study, we included all patients (n = 955) referred to Beth Israel Deaconess Medical Center for OLT between January 2002 and September 2011 and followed their outcomes through March 2018.

RESULTS

Compared with non-NASH patients (n = 881), NASH patients (n = 74) were older, more likely female, more overweight, with higher rates of diabetes, hypertension and CVD. NASH patients were less likely to be listed for OLT (55% vs 68.9%, P = 0.01) and were more often declined for 'medical comorbidities' (36.1% vs 15.7%, P < 0.001). However, on multivariate analysis, the only significant predictors of listing were model for end-stage liver disease (MELD) score (OR 1.04, P = 0.01), HCC (OR 2.16, P = 0.01), and diagnosis of non-NASH cirrhosis (OR 2.56, P = 0.003) while controlling for comorbidities. NASH patients declined for OLT died primarily from their liver disease and were not more likely to die from CVD than non-NASH patients. There was no difference in outcomes of NASH vs non-NASH patients on the waitlist and post-transplant.

CONCLUSIONS

This study demonstrates potential bias against NASH patients referred for OLT arising from heightened concern for comorbidities. Despite being declined for comorbidities, NASH patients are likely to die of their liver disease.

A Pathophysiologic Approach Combining Genetics and Insulin Resistance to Predict the Severity of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a complex disease dictated by both genetic and environmental factors. While insulin resistance (IR) is a key pathogenic driver, two common genetic variants in patatin‐like phospholipase domain containing 3 (PNPLA3) and transmembrane 6 superfamily member 2 (TM6SF2) also impart significant risk for disease progression. Traditional approaches to NAFLD risk stratification rely on biomarkers of fibrosis, an end result of disease progression. We hypothesized that by combining genetics and a novel measurement for IR we could predict disease progression by the NAFLD activity score (NAS) and histologic presence of significant fibrosis. A total of 177 patients with biopsy‐proven NAFLD were enrolled in this cross‐sectional study. PNPLA3 I148M and TM6SF2 E167K genotypes were determined by TaqMan assays. The enhanced lipoprotein IR index (eLP‐IR) was calculated from serum biomarkers using nuclear magnetic resonance (NMR) spectroscopy. Multivariate regression models were used to study the relationships between genetics, IR, and histologic features of NAFLD. In the multivariate analysis, the eLP‐IR was strongly associated with histologic features of NAFLD activity and hepatic fibrosis (P < 0.001 to 0.02) after adjustment for potential confounders. PNPLA3 148M and TM6SF2 E167K genotypes were significantly associated with steatosis (P = 0.003 and P = 0.02, respectively). A combination of the eLP‐IR and genetic score was able to predict the presence of NAS ≥3 with an area under the receiver operating characteristic curve (AUROC) of 0.74. Adding age to this model predicted stages 3‐4 liver fibrosis with an AUROC of 0.82. Conclusion: This proof‐of‐concept study supports the hypothesis that genetics and IR are major determinants of NAFLD severity and demonstrates the feasibility of a new risk stratification paradigm using exclusively pathogenic factors.

Osteoporosis in primary biliary cholangitis

Primary biliary cholangitis (PBC) is an autoimmune cholestatic liver disease with multiple debilitating complications. Osteoporosis is a common complication of PBC resulting in frequent fractures and leading to significant morbidity in this population, yet evidence for effective therapy is lacking. We sought to summarize our current understanding of the pathophysiology of osteoporosis in PBC, as well as current and emerging therapies in order to guide future research directions. A complete search with a comprehensive literature review was performed with studies from PubMed, EMBASE, Web of Science, Cochrane database, and the Countway Library. Osteoporosis in PBC is driven primarily by decreased bone formation, which differs from the increased bone resorption seen in postmenopausal osteoporosis. Despite this fundamental difference, current treatment recommendations are based primarily on experience with postmenopausal osteoporosis. Trials specific to PBC-related osteoporosis are small and have not consistently demonstrated a benefit in this population. As it stands, prevention of osteoporosis in PBC relies on the mitigation of risk factors such as smoking and alcohol use, as well as encouraging a healthy diet and weight-bearing exercise. The primary medical intervention for the treatment of osteoporosis in PBC remains bisphosphonates though a benefit in terms of fracture reduction has never been shown. This review outlines what is known regarding the pathogenesis of bone disease in PBC and summarizes current and emerging therapies.

Non-alcoholic fatty liver disease: a narrative review of genetics

Non-alcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver diseases worldwide. It encompasses a spectrum of disorders ranging from isolated hepatic steatosis to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. One of the key challenges in NAFLD is identifying which patients will progress. Epidemiological and genetic studies indicate a strong pattern of heritability that may explain some of the variability in NAFLD phenotype and risk of progression. To date, at least three common genetic variants in the PNPLA3, TM6SF2, and GCKR genes have been robustly linked to NAFLD in the population. The function of these genes revealed novel pathways implicated in both the development and progression of NAFLD. In addition, candidate genes previously implicated in NAFLD pathogenesis have also been identified as determinants or modulators of NAFLD phenotype including genes involved in hepatocellular lipid handling, insulin resistance, inflammation, and fibrogenesis. This article will review the current understanding of the genetics underpinning the development of hepatic steatosis and the progression of NASH. These newly acquired insights may transform our strategy to risk-stratify patients with NAFLD and to identify new potential therapeutic targets.

Encapsulating peritoneal sclerosis

Encapsulating peritoneal sclerosis (EPS) is a debilitating condition characterized by a fibrocollagenous membrane encasing the small intestine, resulting in recurrent small bowel obstructions. EPS is most commonly associated with long-term peritoneal dialysis, though medications, peritoneal infection, and systemic inflammatory disorders have been implicated. Many cases remain idiopathic. Diagnosis is often delayed given the rarity of the disorder combined with non-specific symptoms and laboratory findings. Although cross-sectional imaging with computed tomography of the abdomen can be suggestive of the disorder, many patients undergo exploratory laparotomy for diagnosis. Mortality approaches 50% one year after diagnosis. Treatment for EPS involves treating the underlying condition or eliminating possible inciting agents (i.e. peritoneal dialysis, medications, infections) and nutritional support, frequently with total parenteral nutrition. EPS-specific treatment depends on the disease stage. In the inflammatory stage, corticosteroids are the treatment of choice, while in the fibrotic stage, tamoxifen may be beneficial. In practice, distinguishing between stages may be difficult and both may be used. Surgical intervention, consisting of peritonectomy and enterolysis, is time-consuming and high-risk and is reserved for situations in which conservative medical therapy fails in institutions with surgical expertise in this area. Herein we review the available literature of the etiology, pathogenesis, diagnosis, and treatment of this rare, but potentially devastating disease.

Risk factors for hepatocellular carcinoma in cirrhosis due to nonalcoholic fatty liver disease: A multicenter, case-control study

AIM

To identify risk factors associated with hepatocellular carcinoma (HCC), describe tumor characteristics and treatments pursed for a cohort of individuals with nonalcoholic steatohepatitis (NASH) cirrhosis.

METHODS

We conducted a retrospective case-control study of a well-characterized cohort of patients among five liver transplant centers with NASH cirrhosis with (cases) and without HCC (controls).

RESULTS

Ninety-four cases and 150 controls were included. Cases were significantly more likely to be male than controls (67% vs 45%, P < 0.001) and of older age (61.9 years vs 58 years, P = 0.002). In addition, cases were more likely to have had complications of end stage liver disease (83% vs 71%, P = 0.032). On multivariate analysis, the strongest association with the presence of HCC were male gender (OR 4.3, 95%CI: 1.83-10.3, P = 0.001) and age (OR = 1.082, 95%CI: 1.03-1.13, P = 0.001). Hispanic ethnicity was associated with a decreased prevalence of HCC (OR = 0.3, 95%CI: 0.09-0.994, P = 0.048). HCC was predominantly in the form of a single lesion with regional lymph node(s) and distant metastasis in only 2.6% and 6.3%, respectively. Fifty-nine point three percent of individuals with HCC underwent locoregional therapy and 61.5% underwent liver transplantation for HCC.

CONCLUSION

Male gender, increased age and non-Hispanic ethnicity are associated with HCC in NASH cirrhosis. NASH cirrhosis associated HCC in this cohort was characterized by early stage disease at diagnosis and treatment with locoregional therapy and transplant.

Clinical Implications of a Multivariate Stratification Model for the Estimation of Prognosis in Ventricular Septal Defect

OBJECTIVES

To derive and validate a multivariate stratification model for prediction of survival free from intervention (SFFI) in ventricular septal defect (VSD). A secondary aim is for this model to serve as proof of concept for derivation of a more general congenital heart disease prognostic model, of which the VSD model will be the first component.

STUDY DESIGN

For 12 years, 2334 subjects with congenital heart disease were prospectively and consecutively enrolled. Of these, 675 had VSD and form the derivation cohort. One hundred seven other subjects with VSD followed in another practice formed the validation cohort. The derivation cohort was serially stratified based on clinical and demographic features correlating with SFFI.

RESULTS

Six strata were defined, the most favorable predicting nearly 100% SFFI at 10 years, and the least favorable, a high likelihood of event within weeks. Strata with best SFFI had many subjects with nearly normal physiology, muscular VSD location, or prior intervention. In the validation cohort, the relation between predicted and actual SFFI at 6 months, 1 year, 2 years, and 5 years follow-up had areas under the receiver operating characteristic curves 0.800 or greater.

CONCLUSIONS

A prediction model for SFFI in VSD has been derived and validated. It has potential for clinical application to the benefit of patients and families, medical trainees, and practicing physicians.

HBV infection is associated with greater mortality in hospitalised patients compared to HCV infection or alcoholic liver disease

BACKGROUND

Little is known about outcomes of Hepatitis B virus (HBV)-related hospitalisations.

AIM

To compare the characteristics and outcomes of hospitalised HBV patients to those with Hepatitis C virus (HCV) infection and alcoholic liver disease (ALD), and to examine variables associated with poor outcomes.

METHODS

Using the 2011 US Nationwide Inpatient Sample, we identified hospitalised patients with HBV, HCV or ALD-related admissions using ICD-9-CM codes. We compared liver-related complications between the three groups. Multivariable regression was performed to identify factors associated with in-hospital mortality and length of stay.

RESULTS

A total of 22 843 HBV, 203 300 HCV and 244 383 ALD-related discharges were included. Cirrhosis was noted less commonly in those with HBV (69.1%) compared to HCV (83.9%) or ALD (80.9%) (P < 0.001). In contrast, hepatocellular cancer and acute liver failure were more common with HBV (16.5% and 5.2%) compared to HCV (10.4% and 2.8%) or ALD (2.5% and 4.9%) respectively (P < 0.0001). On multivariable analysis, adjusting for demographics, liver and nonliver comorbidity, HBV infection was associated with higher mortality compared to HCV infection [Odds ratio (OR) 1.21, 95% CI: 1.04-1.39) or ALD (OR: 1.21, 95% CI: 1.05-1.40). Length of hospital stay was greater with HBV compared to HCV (+0.54 days) or ALD (+0.36 days). Among those with HBV, significant factors associated with mortality included renal failure, hepatocellular cancer, respiratory failure, ascites, coagulopathy and acute liver failure.

CONCLUSION

Patients hospitalised with HBV infection represent a particularly high-risk group with poor in-hospital outcomes and increased mortality compared to HCV infection or alcoholic liver disease.

Main pulmonary artery dilation in association with congenital bicuspid aortic valve in the absence of pulmonary valve abnormality

BACKGROUND

Main pulmonary artery (MPA) dilation is reported to occur in association with pulmonary valve (PV) abnormalities and in genetic diseases of connective tissue.

AIM

To determine whether MPA dilation occurs with bicuspid aortic valve (BAV) in the absence of PV abnormality.

METHODS

MPA and aortic dimensions were investigated in 194 subjects with BAV and 178 controls matched for age, sex and body surface area (BSA) using transthoracic two-dimensional echocardiography. Using control measurements, linear regression of each parameter versus age, gender, and BSA(2/3) provided expected values. For each subject with BAV, the percentage divergence from expected value ((observed--expected value)/expected value) for each dimension was analysed.

RESULTS

MPA and aortic measurements showed normal distribution in all subjects. PV annulus and MPA were larger in BAV; 17.7% positive divergence of MPA dimension from expected was found in diastole, and 16.7% in systole. Aortic dimensions at all levels measured were larger in BAV; divergence was greater distally than proximally (10% divergence at annulus, 31% at ascending aorta). In BAV, divergence of ascending aortic dimensions from expected values increased with age (r(2)=0.142, p=0.02), but MPA divergence from expected values did not increase with age (r(2)=0.001, p=0.296).

CONCLUSIONS

MPA dilation occurs in association with BAV in the absence of PV abnormality, suggesting primary vessel wall pathology predisposing to arterial dilation. A systemic abnormality of connective tissue common to both arteries may be responsible, or the dilation may result from a common developmental exposure as both originate from the embryologic cono-truncus.