Discrimination of Nonalcoholic Steatohepatitis Using Transient Elastography in Patients with Nonalcoholic Fatty Liver Disease

Envisioning how to advance the MASH field

Since 1980, the cumulative effort of scientists and health-care stakeholders has advanced the prerequisites to address metabolic dysfunction-associated steatotic liver disease (MASLD), a prevalent chronic non-communicable liver disease. This effort has led to, among others, the approval of the first drug specific for metabolic dysfunction-associated steatohepatitis (MASH; formerly known as nonalcoholic steatohepatitis). Despite substantial progress, MASLD is still a leading cause of advanced chronic liver disease, including primary liver cancer. This Perspective contextualizes the nomenclature change from nonalcoholic fatty liver disease to MASLD and proposes important considerations to accelerate further progress in the field, optimize patient-centric multidisciplinary care pathways, advance pharmacological, behavioural and diagnostic research, and address health disparities. Key regulatory and other steps necessary to optimize the approval and access to upcoming additional pharmacological therapeutic agents for MASH are also outlined. We conclude by calling for increased education and awareness, enhanced health system preparedness, and concerted action by policy-makers to further the public health and policy agenda to achieve at least parity with other non-communicable diseases and to aid in growing the community of practice to reduce the human and economic burden and end the public health threat of MASLD and MASH by 2030.

Predictive Algorithm for Hepatic Steatosis Detection Using Elastography Data in the Veterans Affairs Electronic Health Records

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) has reached pandemic proportions. Early detection can identify at-risk patients who can be linked to hepatology care. The vibration-controlled transient elastography (VCTE) controlled attenuation parameter (CAP) is biopsy validated to diagnose hepatic steatosis (HS). We aimed to develop a novel clinical predictive algorithm for HS using the CAP score at a Veterans' Affairs hospital.

METHODS

We identified 403 patients in the Greater Los Angeles VA Healthcare System with valid VCTEs during 1/2018-6/2020. Patients with alcohol-associated liver disease, genotype 3 hepatitis C, any malignancies, or liver transplantation were excluded. Linear regression was used to identify predictors of NAFLD. To identify a CAP threshold for HS detection, receiver operating characteristic analysis was applied using liver biopsy, MRI, and ultrasound as the gold standards.

RESULTS

The cohort was racially/ethnically diverse (26% Black/African American; 20% Hispanic). Significant positive predictors of elevated CAP score included diabetes, cholesterol, triglycerides, BMI, and self-identifying as Hispanic. Our predictions of CAP scores using this model strongly correlated (r = 0.61, p < 0.001) with actual CAP scores. The NAFLD model was validated in an independent Veteran cohort and yielded a sensitivity of 82% and specificity 83% (p < 0.001, 95% CI 0.46-0.81%). The estimated optimal CAP for our population cut-off was 273.5 dB/m, resulting in AUC = 75.5% (95% CI 70.7-80.3%).

CONCLUSION

Our HS predictive algorithm can identify at-risk Veterans for NAFLD to further risk stratify them by non-invasive tests and link them to sub-specialty care. Given the biased referral pattern for VCTEs, future work will need to address its applicability in non-specialty clinics. Proposed clinical algorithm to identify patients at-risk for NAFLD prior to fibrosis staging in Veteran.

Glucocorticoid Replacement for Adrenal Insufficiency and the Development of Non-Alcoholic Fatty Liver Disease

Glucocorticoid excess is a known risk factor for non-alcoholic fatty liver disease (NAFLD). Our objective was to analyse the impact of glucocorticoid replacement therapy on the development of NAFLD and NAFLD-related fibrosis and, therefore, on cardiovascular as well as hepatic morbidity in patients with adrenal insufficiency. Two hundred and fifteen individuals with primary (n = 111) or secondary (n = 104) adrenal insufficiency were investigated for hepatic steatosis and fibrosis using the fatty liver index (FLI), NAFLD fibrosis score (NAFLD-FS), Fibrosis-4 Index (FiB-4) plus sonographic transient elastography. Results were correlated with glucocorticoid doses and cardiometabolic risk parameters. The median dose of hydrocortisone equivalent was 20 mg daily, with a median therapy duration of 15 years. The presence and grade of hepatic steatosis and fibrosis were significantly correlated with cardiometabolic risk factors. We could not find any significant correlations between single, daily or cumulative doses of glucocorticoids and the grade of liver steatosis, nor with fibrosis measured via validated sonographic techniques. In patients with adrenal insufficiency, glucocorticoid replacement within a physiological range of 15-25 mg hydrocortisone equivalent per day does not appear to pose an additional risk for the development of NAFLD, subsequent liver fibrosis, or the cardiovascular morbidity associated with these conditions.

Liver Ultrasound Elastography in Non-Alcoholic Fatty Liver Disease: A State-of-the-Art Summary

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease which is currently the most common hepatic disorder affecting up to 38% of the general population with differences according to age, country, ethnicity and sex. Both genetic and acquired risk factors such as a high-calorie diet or high intake of saturated fats have been associated with obesity, diabetes and, finally, NAFLD. A liver biopsy has always been considered essential for the diagnosis of NAFLD; however, due to several limitations such as the potential occurrence of major complications, sampling variability and the poor repeatability in clinical practice, it is considered an imperfect option for the evaluation of liver fibrosis over time. For these reasons, a non-invasive assessment by serum biomarkers and the quantification of liver stiffness is becoming the new frontier in the management of patients with NAFLD and liver fibrosis. We present a state-of-the-art summary addressing the methods for the non-invasive evaluation of liver fibrosis in NAFLD patients, particularly the ultrasound-based techniques (transient elastography, ARFI techniques and strain elastography) and their optimal cut-off values for the staging of liver fibrosis.

[State of the art on the pathophysiology, diagnosis and treatment of non-alcoholic steatohepatitis (NASH)]

NAFLD or non-alcoholic fatty liver disease is one of the complications of obesity and diabetes, the prevalence of which is increasing. The causes of the pathology and its development towards its severe form, NASH or non-alcoholic steatohepatitis, are multiple and still poorly understood. Many different pharmacological classes are being tested in clinical trials to treat NASH, but no pharmaceutical treatment is currently on the market. Moreover, the diagnosis of certainty is only possible by liver biopsy and histological analysis, an invasive procedure with high risk for the patient. It is therefore necessary to better understand the natural history of the disease in order to identify therapeutic targets, but also to identify markers for the diagnosis and monitoring of the disease using a blood sample, which will allow an improvement in patient management.

Non-invasive biomarkers for liver inflammation in non-alcoholic fatty liver disease: present and future

Inflammation is the key driver of liver fibrosis progression in non-alcoholic fatty liver disease (NAFLD). Unfortunately, it is often challenging to assess inflammation in NAFLD due to its dynamic nature and poor correlation with liver biochemical markers. Liver histology keeps its role as the standard tool, yet it is well-known for substantial sampling, intraobserver, and interobserver variability. Serum proinflammatory cytokines and apoptotic markers, namely cytokeratin-18, are well-studied with reasonable accuracy, whereas serum metabolomics and lipidomics have been adopted in some commercially available diagnostic models. Ultrasound and computed tomography imaging techniques are attractive due to their wide availability; yet their accuracies may not be comparable with magnetic resonance imaging-based tools. Machine learning and deep learning models, be they supervised or unsupervised learning, are promising tools to identify various subtypes of NAFLD, including those with dominating liver inflammation, contributing to sustainable care pathways for NAFLD.

Triglyceride affects the association between estimated glomerular filtration rate and the onset of non-alcoholic fatty liver disease: A second analysis of a Chinese cohort study

Objective

The role of triglyceride (TG) and estimated glomerular filtration rate (eGFR) effect modifiers on the risk of non-alcoholic fatty liver disease (NAFLD) is unknown. This study examined whether TG modifies the relationship between eGFR and incident NAFLD.

Methods

In a Chinese hospital from January 2010 to December 2014, 15,555 non-obese subjects were collected systematically for this retrospective cohort study. The target-independent and dependent variables were eGFR measured at baseline and NAFLD appearing during follow-up. The modified variable was TG measured at baseline. The multivariate Cox proportional hazards model was used to explore eGFR and TG’s association with NAFLD risk. We explored a priori interaction between eGFR and TG, and performed subgroup analyses to further assess whether the relationship between eGFR and incident NAFLD was modified by TG. We also explored the effect of TG and eGFR interaction on the risk of NAFLD.

Results

The mean age was 43.09 ± 14.92 years, and 8,131 (52.27%) were males. During a median follow-up time of 35.8 months, 2,077 (13.35%) individuals developed NAFLD. In the adjusted model, eGFR was negatively associated with incident NAFLD (HR = 0.984, 95% CI: 0.982, 0.987), while TG was positively related to NAFLD (HR = 1.582, 95% CI: 1.490, 1.681). TG could modify the relationship between eGFR and incident NAFLD. A stronger association between eGFR and NAFLD could be found in the participants without hypertriglyceridemia (HTG) (HR = 0.981, 95% CI: 0.978–0.984, P for interaction = 0.0139). In contrast, the weaker association was probed in the population with HTG (HR = 0.986, 95% CI: 0.983–0.989). At the same time, we also found an interaction between eGFR and TG in influencing NAFLD risk. In participants with decreased eGFR and HTG, the risk of NAFLD was significantly increased. Further, compared to non-HTG subjects with eGFR ≥ 116.56 ml/min/1.73 m², participants with HTG and eGFR < 82.88 ml/min/1.73 m² had about a fourfold increase in the risk (HR = 4.852 95% CI: 3.943–5.970) of NAFLD.

Conclusion

eGFR and TG is independently associated with NAFLD risk. The association of eGFR with incident NAFLD is likely to be modified by TG in the Chinese non-obese population. There was an interactive effect between eGFR and TG in affecting NAFLD risk. In participants with decreased eGFR and hypertriglyceridemia, the risk of NAFLD is significantly increased.

European guideline on obesity care in patients with gastrointestinal and liver diseases - Joint European Society for Clinical Nutrition and Metabolism / United European Gastroenterology guideline

BACKGROUND

Patients with chronic gastrointestinal (GI) disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean GI patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The objective of the guideline is to give advice to all professionals working in the field of gastroenterology care including physicians, surgeons, dietitians and others how to handle patients with GI disease and obesity.

METHODS

The present guideline was developed according to the standard operating procedure for European Society for Clinical Nutrition and Metabolism guidelines, following the Scottish Intercollegiate Guidelines Network grading system (A, B, 0, and good practice point [GPP]). The procedure included an online voting (Delphi) and a final consensus conference.

RESULTS

In 100 recommendations (3x A, 33x B, 24x 0, 40x GPP, all with a consensus grade of 90% or more) care of GI patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially fatty liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present guideline offers for the first time evidence-based advice how to care for patients with chronic GI diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

European guideline on obesity care in patients with gastrointestinal and liver diseases - Joint ESPEN/UEG guideline

BACKGROUND

Patients with chronic gastrointestinal (GI) disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean GI patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The objective of the guideline is to give advice to all professionals working in the field of gastroenterology care including physicians, surgeons, dietitians and others how to handle patients with GI disease and obesity.

METHODS

The present guideline was developed according to the standard operating procedure for ESPEN guidelines, following the Scottish Intercollegiate Guidelines Network (SIGN) grading system (A, B, 0, and good practice point (GPP)). The procedure included an online voting (Delphi) and a final consensus conference.

RESULTS

In 100 recommendations (3x A, 33x B, 24x 0, 40x GPP, all with a consensus grade of 90% or more) care of GI patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially fatty liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present guideline offers for the first time evidence-based advice how to care for patients with chronic GI diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

Validation of the accuracy of the FAST™ score for detecting patients with at-risk nonalcoholic steatohepatitis (NASH) in a North American cohort and comparison to other non-invasive algorithms

BACKGROUND AND AIMS

Management of patients with NASH who are at elevated risk of progressing to complications of cirrhosis (at-risk NASH) would be enhanced by an accurate, noninvasive diagnostic test. The new FAST™ score, a combination of FibroScan® parameters liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) and aspartate aminotransferase (AST), has shown good diagnostic accuracy for at-risk NASH (area-under-the-Receiver-Operating-Characteristic [AUROC] = 0.80) in European cohorts. We aimed to validate the FAST™ score in a North American cohort and show how its diagnostic accuracy might vary by patient mix. We also compared the diagnostic performance of FAST™ to other non-invasive algorithms for the diagnosis of at-risk NASH.

METHODS

We studied adults with biopsy-proven non-alcoholic fatty liver disease (NAFLD) from the multicenter NASH Clinical Research Network (CRN) Adult Database 2 (DB2) cohort study. At-risk-NASH was histologically defined as definite NASH with a NAFLD Activity Score (NAS) ≥ 4 with at least 1 point in each category and a fibrosis stage ≥ 2. We used the Echosens® formula for FAST™ from LSM (kPa), CAP (dB/m), and AST (U/L), and the FAST™-based Rule-Out (FAST™ ≤ 0.35, sensitivity = 90%) and Rule-In (FAST™ ≥ 0.67, specificity = 90%) zones. We determined the following diagnostic performance measures: AUROC, sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV); these were calculated for the total sample and by subgroups of patients and by FibroScan® exam features. We also compared the at-risk NASH diagnostic performance of FAST™ to other non-invasive algorithms: NAFLD fibrosis score (NFS), Fibrosis-4 (FIB-4) index, and AST to platelet ratio index (APRI).

RESULTS

The NASH CRN population of 585 patients was 62% female, 79% white, 14% Hispanic, and 73% obese; the mean age was 51 years. The mean (SD) AST and ALT were 50 (37) U/L and 66 (45) U/L, respectively. 214 (37%) had at-risk NASH. The AUROC of FAST™ for at-risk NASH in the NASH CRN study population was 0.81 (95% CI: 0.77, 0.84. Using FAST™-based cut-offs, 35% of patients were ruled-out with corresponding NPV = 0.90 and 27% of patients were ruled-in with corresponding PPV = 0.69. The diagnostic accuracy of FAST™ was higher in non-whites vs. whites (AUROC: 0.91 vs 0.78; p = 0.001), and in patients with a normal BMI vs. BMI > 35 kg/m2 (AUROC: 0.94 vs 0.78, p = 0.008). No differences were observed by other patient characteristics or FibroScan® exam features. The FAST™ score had higher diagnostic accuracy than other non-invasive algorithms for the diagnosis of at-risk NASH (AUROC for NFS, FIB-4, and APRI 0.67, 0.73, 0.74, respectively).

CONCLUSION

We validated the FAST™ score for the diagnosis of at-risk NASH in a large, multi-racial population in North America, with a prevalence of at-risk NASH of 37%. Diagnostic performance varies by subgroups of NASH patients defined by race and obesity. FAST™ performed better than other non-invasive algorithms for the diagnosis of at-risk NASH.

The Coexistence of Nonalcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus

The incidence of nonalcoholic fatty liver disease (NAFLD) is growing worldwide. Epidemiological data suggest a strong relationship between NAFLD and T2DM. This is associated with common risk factors and pathogenesis, where obesity, insulin resistance and dyslipidemia play pivotal roles. Expanding knowledge on the coexistence of NAFLD and T2DM could not only protect against liver damage and glucotoxicity, but may also theoretically prevent the subsequent occurrence of other diseases, such as cancer and cardiovascular disorders, as well as influence morbidity and mortality rates. In everyday clinical practice, underestimation of this problem is still observed. NAFLD is not looked for in T2DM patients; on the contrary, diagnosis for glucose metabolism disturbances is usually not performed in patients with NAFLD. However, simple and cost-effective methods of detection of fatty liver in T2DM patients are still needed, especially in outpatient settings. The treatment of NAFLD, especially where it coexists with T2DM, consists mainly of lifestyle modification. It is also suggested that some drugs, including hypoglycemic agents, may be used to treat NAFLD. Therefore, the aim of this review is to detail current knowledge of NAFLD and T2DM comorbidity, its prevalence, common pathogenesis, diagnostic procedures, complications and treatment, with special attention to outpatient clinics.

Triglyceride: A mediator of the association between waist-to-height ratio and non-alcoholic fatty liver disease: A second analysis of a population-based study

OBJECTIVE

Increasing evidence suggests that an increased waist-to-height ratio (WHtR) may increase the risk of non-alcoholic fatty liver disease (NAFLD). Whether this association is due to WHtR itself or mediated by WHtR-associated increases in triglyceride (TG) is uncertain. On that account, our research aims to disentangle these relationships.

METHODS

In this cross-sectional study, 14251 participants who participated in the medical examination program were consecutively and non-selectively collected in Murakami Memorial Hospital in Japan from 2004 to 2015. The independent and dependent variables were WHtR and NAFLD, respectively. Triglyceride was the mediating factor. The correlation between WHtR, TG, and NAFLD risk factors was examined using spearman correlation analysis. The association between WHtR or TG and NAFLD was examined using multiple logistic regression. In order to determine whether TG mediated the association between WHtR and NAFLD, a mediation analysis was performed.

RESULTS

The mean age of the included individuals was 43.53 ± 8.89 years old, and 7411 (52.00%) were male. The mean WHtR and TG were 0.46 ± 0.05, 0.89 ± 0.63, respectively. The prevalence rate of NAFLD was 2507 (17.59%). Individuals with NAFLD had significantly higher levels of WHtR and TG than those without NAFLD (P&lt;0.05). After adjusting covariates, the multivariate linear regression analysis showed that WHtR was positively associated with TG. That was, for every 0.1 increase in WHtR, TG increased by 0.226mmol/L (β=0.226, 95%CI: 0.206, 0.247). Multiple logistic regression analysis indicated that WHtR (OR=8.743, 95%CI: 7.528, 10.153) and TG (OR=1.897, 95%CI: 1.732, 2.078) were positively associated with NAFLD. The mediation analysis showed that WHtR had a direct, significant effect on NAFLD (β=0.139, 95%CI: 0.126, 0.148), and TG partially mediated the indirect effect of WHtR on NAFLD (β=0.016, 95% CI: 0.013-0.019). TG contributed to 10.41% of WHtR-related NAFLD development.

CONCLUSION

Findings suggest a mediation link between WHtR and TG and the risk of NAFLD. The significance of TG as a mediator deserves recognition and consideration.

Non-invasive assessment of fibrosis and steatosis in pediatric non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Non-Alcoholic Fatty Liver Disease (NAFLD) has become one of the most common causes of chronic liver disease in the pediatric population. Recent advances have been made in developing non-invasive measures for NAFLD assessment. This review presents an analysis of these latest developments and also proposes an algorithm for screening pediatric patients at risk for NAFLD.

METHODS

A systematic literature search on PUBMED and EMBASE was conducted. Guidelines for clinical care of pediatric NAFLD were also reviewed.

RESULTS

In imaging tests, transient elastography (TE) combined with controlled attenuation parameter (CAP) is a promising, relatively low-cost method offering an intermediate level of accuracy on accessing patient's fibrosis and steatosis in a singular package. Liver biopsy remains the gold standard for diagnosis and/or evaluation of NAFLD, but with our proposed algorithm on utilizing non-invasive testing, the number of liver biopsies required could decrease. The current evidence supports the implementation of TE and CAP in an evaluation algorithm for pediatric NAFLD.

CONCLUSIONS

Current data support the use of TE and CAP as a first-line tool in the diagnosis and evaluation of adolescent NAFLD, to better stratify high-risk patients and cut down on the number of liver biopsies needed.

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

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

Efficacy of sofosbuvir/velpatasvir/voxilaprevir in direct-acting antiviral experienced patients with hepatitis C virus

AIMS

Report the real-world experience of the efficacy and safety of sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) in chronic hepatitis C virus (HCV) infected patients who have previously experienced a direct-acting antiviral (DAA) containing regimen.

METHODS

Consecutive patients who have previously failed or did not tolerate a DAA containing regimen for chronic HCV who was treated with SOF/VEL/VOX were studied. Baseline clinical and laboratory data including NS5A RAS mutation testing were collected.

RESULTS

SOF/VEL/VOX resulted in an end of treatment undetectable HCV viral load in all patients and a sustained virologic response 12 rate of 100% despite the presence of NS5A RAS mutation, HIV infection, and cirrhosis. Treatment with SOF/VEL/VOX was well tolerated and there were no adverse events.

CONCLUSIONS

SOF/VEL/VOX is well tolerated and effective in treating patients who have been exposed to prior DAA therapy outside of clinical trials. SOF/VEL/VOX should be considered as the first-line regimen in HCV infected patients who have experienced prior DAA failure.

A meta-analysis on the diagnostic performance of magnetic resonance imaging and transient elastography in nonalcoholic fatty liver disease

BACKGROUND

Noninvasive methods have been used for the assessment of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD). The aim was to assess the efficacy and accuracy of both magnetic resonance imaging(MRI) and transient elastography(TE) for the evaluation of hepatic steatosis.

MATERIALS AND METHODS

The PubMed, Cochrane Library, Embase, MEDLINE and Web of Science databases were searched to retrieve studies examining the accuracy of MRI-proton density fat fraction(PDFF) and TE-controlled attenuation parameter(CAP) for evaluating the grading of steatosis(S0-S3) diagnosed by liver biopsy in NAFLD. We compared the sensitivity, specificity, hierarchical summary receiver operating characteristic curves(HSROC) and clinical utility of these methods.

RESULTS

Twenty-four articles with a total of 2979 patients with NAFLD were included. The steatosis distribution was 8.1%/35.1%/32.2%/24.6% for S0/S1/S2/S3. For the diagnostic accuracy of MRI-PDFF, the HSROCs were 0.97 for ≥S1, 0.91 for ≥S2 and 0.90 for ≥S3. For the diagnostic accuracy of TE-based CAP, the HSROCs were 0.85 for ≥S1, 0.83 for ≥S2 and 0.79 for ≥S3. Following a 'positive' measurement (over the threshold value) for ≥S1, the corresponding post-test probabilities of PDFF and CAP for the presence of steatosis were 82% and 61%, respectively, when the pretest probability was 24%. If the values were below these thresholds ('negative' results), the post-test probabilities were 3% and 7%.

CONCLUSION

MRI-PDFF and TE-CAP both provide highly accurate noninvasive approaches for quantifying and staging hepatic steatosis in NAFLD. Compared with TE-CAP, MRI-PDFF is significantly more accurate for evaluating dichotomized grades of steatosis.

Transient Elastography in Alcoholic Liver Disease and Nonalcoholic Fatty Liver Disease: A Systemic Review and Meta-Analysis

Background and Aims

Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) have become common chronic liver diseases. Recent evidence has shown the value of transient elastography (TE) in the context of ALD/NAFLD. The aim of this study is to investigate the accuracy of TE for diagnosing steatosis and fibrosis in ALD/NAFLD patients.

Methods

We retrieved relevant English studies from the databases of PubMed, Embase, the Web of Science, and the Cochrane Library through March 31st 2019. We included studies regarding the diagnosis or staging of steatosis or fibrosis by using controlled attenuation parameter (CAP) or liver stiffness measurement (LSM) measured by TE in patients with ALD or NAFLD. The reference standard of all included studies was liver biopsy. A random-effects model was applied. Statistical analyses were performed using STATA.

Results

A total of 62 articles were included and analyzed in our meta-analysis. In patients with ALD/NAFLD, the pooled results revealed that the sensitivity and specificity of CAP were 0.84, 0.83, and 0.78 and 0.83, 0.71, and 0.62 for steatosis grades ≥ S1, ≥S2, and =S3, respectively. The sensitivity and specificity of LSM for identifying fibrosis grades ≥ F1, ≥F2, ≥F3, and =F4 were 0.77, 0.77, 0.83, and 0.91 and 0.80, 0.82, 0.84, and 0.86, respectively.

Conclusion

In patients with ALD/NAFLD, CAP was feasible for identifying and screening steatosis, and LSM was accurate for diagnosing fibrosis, especially severe fibrosis and cirrhosis.

Imaging biomarkers of NAFLD, NASH, and fibrosis

Background

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathologic entity that requires a liver biopsy assessment to diagnose the progressive form of NAFLD called non-alcoholic steatohepatitis (NASH). Liver biopsy is invasive, subject to sampling and interobserver variability, and impractical to scale to the affected population of up to 1 billion affected individuals worldwide. Non-invasive imaging biomarkers have emerged as a key modality to address the major unmet need to diagnose, stage, and longitudinally monitor NAFLD.

Scope of review

In this review, we critically examine the use of non-invasive imaging biomarkers to diagnose NAFLD, NASH, and fibrosis stage.

Major Conclusions

Ultrasound and magnetic resonance imaging (MRI) biomarkers of liver fat can diagnose NAFLD. MRI proton density fat fraction (MRI-PDFF) is better than liver biopsy, particularly for following longitudinal changes in liver fat in clinical trials. Imaging biomarkers to reliably diagnose NASH are under investigation, but when used alone, continue to have only modest diagnostic accuracy. However, the fibrosis stage has the strongest association with liver decompensation and mortality, and elastography has emerged as a reliable biomarker for liver fibrosis. We review the combination of biomarkers to risk stratify patients and identify individuals needing treatment and the implications of longitudinal changes in liver stiffness measurement.

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An improvement of ≥30% in liver fat on MRI-PDFF is associated with histologic improvement.

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Combining MRE ≥3.3 kPa and FIB-4 ≥ 1.6 (MEFIB Index) predicts high-risk NAFLD.

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Elevated liver stiffness measurements predict future hepatic decompensation.

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MRE ≥ 4.67 kPa and ≥8 kPa predict cirrhosis and hepatic decompensation, respectively.

Physical Activity and Low Glycemic Index Mediterranean Diet: Main and Modification Effects on NAFLD Score. Results from a Randomized Clinical Trial

Background: Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common chronic liver disease worldwide, and lifestyle modification is the current standard treatment. The aim of the study was to estimate the effect of two different physical activity (PA) programs, a Low Glycemic Index Mediterranean Diet (LGIMD), and their combined effect on the NAFLD score as measured by FibroScan^®. Methods: Moderate or severe NAFLD subjects (n = 144) were randomly assigned to six intervention arms during three months. Interventions arms were a control diet, LGIMD, aerobic activity program (PA1), combined activity program (PA2), and LGIMD plus PA1 or LGIMD plus PA2. The data were compared at baseline, at 45 days, and at 90 days. Analysis of variance was performed under the intention-to-treat principle. Results: There was a statistically significant reduction in the NAFLD score after 45 days of treatment in every working arm except for Arm 1 (control diet). After 90 days, the best results were shown by the intervention arms in which LGIMD was associated with PA: LGIMD plus PA1 (−61.56 95% CI −89.61, −33.50) and LGIMD plus PA2 (−38.15 95% CI −64.53, −11.77). Conclusion: All treatments were effective to reduce NAFLD scores, but LGIMD plus PA1 was the most efficient.

The Role of Elastography in Non-Alcoholic Fatty Liver Disease

The most common liver disease in developing countries is non-alcoholic fatty liver disease (NAFLD). This involves the abnormal accumulation of lipids in the liver, the pathogenesis of the disease being related to dyslipidemia, obesity, insulin resistance and type 2 diabetes. Most often, the diagnosis of NAFLD is incidental, when performing routine blood tests or when performing a transabdominal ultrasound. The NAFLD spectrum ranges from simple forms of hepatic steatosis to the most advanced form of the disease, steatohepatitis (NASH), which in evolution can cause inflammation, fibrosis, cirrhosis of the liver and even liver cancer. For the evaluation of the prognosis and the clinical evolution, the most important parameter to define is the degree of liver fibrosis. Currently, the gold standard remains the liver biopsy, the differentiation between NAFLD and NASH being made only on the basis of histological analysis. However, liver biopsy is an invasive procedure, with numerous risks such as bleeding, lesions of the other organs and complications related to anesthesia, which significantly reduces its widespread use. Moreover, the risk of a false negative result and the increased costs of the procedure further limits its use in current practice. For this reason, non-invasive methods of evaluating the degree of liver fibrosis have gained ground in recent years. Imaging techniques such as elastography have shown promising results in evaluating and staging NAFLD. The aim of this article is to review the current status of the non-invasive tests for the assessment of NAFLD with a focus on the ultrasound-based elastography techniques.

Usefulness of controlled attenuation parameter and liver stiffness measurement for detecting increased arterial stiffness in asymptomatic populations in China

In recent studies, vibration-controlled transient elastography (FibroScan) has been reported as an alternative noninvasive approach for measuring liver steatosis and fibrosis. The present study aimed to investigate the feasibility of FibroScan controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) in the detection of increased arterial stiffness in asymptomatic populations in China.A retrospective cohort recruiting 4747 asymptomatic patients with no underlying causes of liver disease and having FibroScan and brachial-ankle pulse wave velocity (baPWV) during wellness check-up was covered. Nonalcoholic fatty liver disease (NAFLD) was defined as a CAP ≥238 dB/m. NAFLD with significant fibrosis was defined as an LSM ≥7.3 kPa in the presence of NAFLD. Increased arterial stiffness was determined as a BaPWV ≥1.4m/second.Among the 4747 study participants, 1596 subjects (33.6%) suffered from increased arterial stiffness. The prevalence of increased arterial stiffness progressively increased across CAP quartiles and LSM quartiles in NAFLD (23.5%, 30.8%, 38.3%, 43.7%, P < .001 and 33.1%, 36.8%, 40.4%, 48.2%, P < .001, respectively). After conventional cardiovascular risk factors were adjusted (age, sex, overweight, diabetes mellitus, hypertension, hypercholesterolemia, and current smoking habits), multivariate logistic regression analysis revealed that CAP (odd ratio [OR] = 1.005; 95% confidence interval [CI]: 1.003-1.006; P < .001), NAFLD (OR = 1.427; 95% CI: 1.212-1.681; P < .001), LSM in NAFLD (OR = 1.073; 95% CI: 1.023-1.125; P = .003), and significant fibrosis in NAFLD (OR = 1.480; 95% CI: 1.090-2.010; P = .012) were independently associated with increased arterial stiffness. Furthermore, in a multivariate logistic regression analysis, OR (95% CI) for the maximal vs. the minimal quartile of CAP was 1.602 (1.268-2.024), and that of LSM in NAFLD was 1.362 (1.034-1.792) after adjustment for the above-mentioned risk factors. Notably, NAFLD and significant fibrosis in NAFLD were significantly correlated only with increased arterial stiffness in subjects without hypertension or diabetes mellitus after adjustment for the above-mentioned risk factors.CAP-defined NAFLD and LSM-defined significant fibrosis in NAFLD showed significant and independent relationships with increased arterial stiffness even after adjustment for conventional cardiovascular risk factors, which can be conducive to stratifying relative risk of subjects having undergone screening assessment for cardiovascular disease.

Use of imaging techniques for non-invasive assessment in the diagnosis and staging of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease and represent a common finding in highly prevalent metabolic disorders (i.e. type 2 diabetes, metabolic syndrome, obesity). Non-alcoholic steatohepatitis (NASH) requires liver biopsy for grading and staging the liver damage by the assessment of steatosis, inflammation and fibrosis. In parallel with the development of numerous 'liquid' biomarkers and algorithms that combine anthropometric and laboratory parameters, innovative hepatic imaging techniques have increasingly been developed to attempt to overcome the need for biopsy, both in diagnosis and staging of NAFLD, and in possible use in the follow-up of the disease. In this review, we focused on the different imaging techniques trying to highlight the strengths and disadvantages of different approaches, particularly for ultrasound techniques, in stratifying liver injury and fibrosis in patients with NAFLD / NASH.

Effects of anthropometric and metabolic parameters on transaminase levels and liver stiffness in patients with non-alcohol fatty liver disease

We aimed to investigate 214 patients further with non-alcoholic fatty liver disease (NAFLD) as judged by transient elastography. A body mass index of ≥25 was seen in 172 (80%) of the patients. F2-F4 fibrosis, as depicted by elastography, was present in 114 (53.2%). A Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) of ≥2 was seen in 178 (83.2%). Alanine aminotransferase was elevated in 116 (54%) and aspartate aminotransferase in 88 (41.1%). Liver steatosis was significantly associated with increasing alanine aminotransferase, insulin, HOMA-IR and cholesterol levels. Regression analysis showed cholesterol as a factor independently associated with the degree of liver steatosis. The independent variable related to increasing liver elasticity was steatosis. In conclusion, a significant number of our patients with NAFLD had steatohepatitis and F2-F4 fibrosis.

Applicability and Results of Liver Stiffness Measurement and Controlled Attenuation Parameter Using XL Probe for Metabolic-Associated Fatty Liver Disease in Candidates to Bariatric Surgery. A Single-Center Observational Study

PURPOSE

Patients with morbid obesity are at high risk of liver fibrosis due to metabolic-associated fatty liver disease. Data on liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) by vibration-controlled transient elastography (VCTE, FibroScan®) XL probe for liver fibrosis and steatosis assessment in morbid obesity are needed.

MATERIALS AND METHODS

LSM and CAP were measured in candidates to bariatric surgery at a single center during 12 months. In patients who underwent an intraoperative liver biopsy, we compared LSM and CAP with histology findings. Comorbidities, body mass index, type of surgery, and infections after surgery were collected and analyzed.

RESULTS

Of the eighty-three patients assessed by XL probe, 49 (59%; female in 63%, BMI 42.6 ± 5.1 kg/m²) had a valid LSM and CAP measurement. LSM was 7.0 ± 3.9 kPa and CAP 329 ± 57 dB/m. In the 14 patients undergoing intraoperative liver biopsy, all had steatosis (severe in 50%), 6 (43%) had NASH (NAS ≥ 5), and 4 (29%) showed significant or bridging fibrosis. LSM accurately discriminated between patients with and without significant or severe fibrosis (AUROC 0.833) and CAP well-identified patients with or without ≥S2 steatosis (AUROC 0.896). Nine of 49 patients (18%) tested positive for significant/severe fibrosis by LSM (cut-off 8.9 kPa).

CONCLUSION

Applicability of LSM and CAP by XL probe in patients candidate to bariatric surgery was moderate. However, when technically successful, their reliability to diagnose severe steatosis and fibrosis related to MAFLD was good.

Higher cut-off values of non-invasive methods might be needed to detect moderate-to-severe steatosis in morbid obese patients: a pilot study

To evaluate the diagnostic value of described thresholds of controlled attenuation parameter (CAP) and biomarker scores for liver steatosis and to evaluate new cut-offs to detect moderate-to-severe steatosis (S2-3) in patients with morbid obesity. In this prospective study, 32 patients with morbid obesity with indications for bariatric surgery (15 women and 17 men, mean age = 36 years, median BMI = 40.2 kg/m²) underwent CAP, magnetic resonance spectroscopy (MRS), three biomarker scores (Steato-ELSA, Fatty Liver Index (FLI), and Hepatic Steatosis Index (HSI)), and liver biopsy. Subjects were divided into an exploratory cohort (reliable CAP and liver biopsy) and a confirmatory cohort (reliable CAP and MRS) to evaluate new thresholds for CAP and biomarker scores to detect S2-3. Receiver operator characteristic (ROC) curves analyses were performed and the optimal cut-off points were identified using the maximal Youden index. A total of 22 patients had CAP measure and liver biopsy (exploratory cohort) and 24 patients had CAP measure with MRS (confirmatory cohort). New cut-offs were identified for detection of S2-3 by the non-invasive tests using liver biopsy as the reference standard (exploratory cohort). Considering the new proposed cut-offs for detection of S2-3 for CAP (≥ 314 dB/m), Steato-ELSA (≥ 0.832), FLI (≥ 96), and HSI (≥ 53), for the exploratory and confirmatory cohorts sensitivities were: 71-75%, 86-81%, 85-81%, and 71-69% and specificities were: 94-89%, 75-63%, 63-63%, and 75-88%, respectively. Higher cut-offs for CAP and biomarker scores may be better to diagnose moderate-to-severe steatosis in patients with morbid obesity.

Advances in Imaging of Diffuse Parenchymal Liver Disease

There are >1.5 billion people with chronic liver disease worldwide, causing liver diseases to be a significant global health issue. Diffuse parenchymal liver diseases, including hepatic steatosis, fibrosis, metabolic diseases, and hepatitis cause chronic liver injury and may progress to fibrosis and eventually hepatocellular carcinoma. As early diagnosis and treatment of these diseases impact the progression and outcome, the need for assessment of the liver parenchyma has increased. While the current gold standard for evaluation of the hepatic parenchymal tissue, biopsy has disadvantages and limitations. Consequently, noninvasive methods have been developed based on serum biomarkers and imaging techniques. Conventional imaging modalities such as ultrasound, computed tomography scan, and magnetic resonance imaging provide noninvasive options for assessment of liver tissue. However, several recent advances in liver imaging techniques have been introduced. This review article focuses on the current status of imaging methods for diffuse parenchymal liver diseases assessment including their diagnostic accuracy, advantages and disadvantages, and comparison between different techniques.

Transient hepatic elastography has the best performance to evaluate liver fibrosis in non-alcoholic fatty liver disease (NAFLD)

INTRODUCTION AND AIM

The gold-standard for fibrosis diagnosis in non-alcoholic fatty liver disease (NAFLD) is liver biopsy, despite its invasive approach, sampling limitations and variability among observers. The objective was to validate the performance of non-invasive methods (Fibroscan™; APRI, FIB4 and NAFLD score) comparing with liver biopsy in the evaluation of liver fibrosis in patients with NAFLD.

MATERIAL AND METHODS

NAFLD patients ≥18 years of age who were submitted to liver biopsy were included and evaluated at two reference tertiary hospitals in Brazil with transient hepatic elastography (THE) assessment through Fibroscan™, APRI, FIB4 and NAFLD scores were determined. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for the diagnosis of advanced fibrosis were calculated to evaluate the performance of these non-invasive methods in NAFLD patients, adopting liver biopsy as the gold standard.

RESULTS

A total of 104 patients were studied. At three different cutoff values (7.9, 8.7 and 9.6kPa) THE presented the highest sensitivity values (95%, 90% and 85% respectively), and the highest NPV (98%, 96.4% and 95.1% respectively) for the diagnosis of advanced fibrosis. It also presented the highest AUROC (0.87; CI 95% 0.78-0.97).

CONCLUSION

When compared to the gold standard, transient hepatic elastography presented the best performance for the diagnosis and exclusion of advanced fibrosis in patients with NAFLD, overcoming APRI, FIB4 and NAFLD score.

Diagnostic accuracy of FibroScan-AST score to identify non-alcoholic steatohepatitis with significant activity and fibrosis in Japanese patients with non-alcoholic fatty liver disease: Comparison between M and XL probes

AIM

Recently, FibroScan-AST (FAST) score was reported to be effective for identifying non-alcoholic steatohepatitis (NASH) with significant activity and fibrosis in non-alcoholic fatty liver disease (NAFLD). The aim of this study was to confirm the diagnostic accuracy of FAST score of Japanese patients and compare the cut-off values and diagnostic accuracy between the FibroScan M and XL probes.

METHODS

Eighty-two and 84 patients were included the verification and validation sets, respectively. All patients were diagnosed with NAFLD by biopsy by two central expert pathologists. Liver stiffness measurements and controlled attenuation parameter were carried out, and diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

No significant difference existed in FAST score between the M and XL probes (0.489 vs. 0.483, P = 0.187). No significant difference existed in the area under the ROC between the two probes (M, 0.7598; XL, 0.7614; P = 0.958). According to the Youden index, the cut-off value using the M probe was 0.57 with 68.2% sensitivity and 78.3% specificity. For the XL probe, the cut-off value was 0.56 with 68.2% sensitivity and 73.3% specificity. To obtain sensitivity and specificity values higher than 90%, cut-off values of 0.35 and 0.66 were chosen for the M probe and 0.32 and 0.63 were chosen for the XL probe.

CONCLUSIONS

There was no significant difference in diagnostic accuracy of FAST score between the FibroScan M and XL probes. The FAST score can be used to identify NASH with significant risk in Japanese patients regardless of probe selection.

When the liver gets stiff, the tough get moving

Liver stiffness measurement (LSM) by FibroScan-determined transient elastography is a noninvasive approach to estimate liver fibrosis severity. In non-alcoholic fatty liver disease (NAFLD), advanced liver fibrosis is excluded by normal liver stiffness, but a wide range of cutoffs have been used to predict advanced liver fibrosis or cirrhosis. This may be partly because steatosis (measured by controlled attenuation parameter [CAP]) contributes to liver stiffness and also because LSM fluctuates in NAFLD. In a recent pivotal study, one-third of patients with liver stiffness > 12.0 kPa showed reversal after 4-6 months; these cases did not have advanced liver fibrosis on biopsy. We performed serial FibroScans 6-36 months apart in 73 NAFLD patients, 38 with LSM > 10 kPa at entry. Those who lost ≥ 1 kg of weight (n = 31) significantly reduced liver stiffness (3.6 ± 6.1 vs 0.53 ± 4.1 kPa, P < 0.05) and CAP score (39 ± 63 dB/m of loss vs 24 ± 65 dB/m of gain, P < 0.05) compared with those who did not (n = 29). Patients who reported increased physical activity (n = 25) also reduced liver stiffness (3.6 ± 6 vs 0.35 ± 6 kPa) and CAP (20 ± 71 dB/m of loss vs 32 ± 71 dB/m of gain). Overall, those with improved LSM were significantly more likely to have lost weight and/or improved physical activity. These effects of lifestyle adjustments partly explain why a single measurement of 12.0 kPa is not a reliable cutoff for advanced liver fibrosis in NAFLD. In addition to repeating the study after 6-12 months, documentation of response to lifestyle advice and weight reduction should be determined before assuming any cutoff indicates advanced liver fibrosis. Despite this reservation about diagnostic accuracy, we consider that measurement of liver stiffness and CAP score serve to motivate patients to enact lifestyle modifications that can improve NAFLD severity.

Controlled attenuation parameter by vibration-controlled transient elastography for steatosis assessment in members of the public undergoing regular health checkups with reference to magnetic resonance imaging-based proton density fat fraction

AIM

Controlled attenuation parameter (CAP) measured by vibration-controlled transient elastography (FibroScan) allows repeatable and reliable assessment of liver steatosis for screening of patients at risk of non-alcoholic steatohepatitis development among asymptomatic individuals at a community level. However, this has never been compared with another quantitative method, such as magnetic resonance imaging-based proton density fat fraction, among the Chinese health checkup population.

METHODS

A multicenter prospective study was conducted with Chinese individuals undergoing regular health checkups. Steatosis grading by magnetic resonance imaging-based proton density fat fraction was used as the reference to evaluate the diagnostic performance of CAP.

RESULTS

A total of 173 individuals were included with mean age of 45 ± 11 years and body mass index of 25.8 ± 4.0 kg/m² . A linear correlation was found between CAP and log₁₀ -transformed magnetic resonance imaging-based proton density fat fraction results (Pearson's coefficient 0.772, P < 0.001). The areas under the receiver operating characteristic curve for distinguishing ≥S1 and ≥S2 steatosis were 0.88 (95% confidence interval 0.83-0.93) and 0.89 (95% confidence interval 0.83-0.95), respectively. When optimized for ≥90% sensitivity, the CAP cut-off for staging ≥S1 steatosis was 244 dB/m. CAP could classify patients with ≥S1 steatosis with similar performance as an ultrasound examination.

CONCLUSIONS

As a non-invasive and quantitative method, CAP is highly adapted for population screening at a community level. With the integration of liver stiffness and CAP results in risk stratification scores for non-alcoholic steatohepatitis, vibration-controlled transient elastography can be useful in regular health checkups.

Reproducibility of ultrasound attenuation imaging for the noninvasive evaluation of hepatic steatosis

PURPOSE

The purpose of this study was to evaluate the intra-observer reproducibility of ultrasound attenuation imaging (ATI) for the noninvasive assessment of hepatic steatosis in patients with suspected hepatic steatosis and the inter-observer reproducibility in asymptomatic volunteers.

METHODS

This prospective study was approved by our institutional review board and informed consent was obtained from all patients. In group 1, composed of patients with suspected hepatic steatosis (n=143), one abdominal radiologist performed gray-scale ultrasonography and two sessions of ATI. In group 2, composed of healthy volunteers (n=18), three independent sessions of ATI were performed by three abdominal radiologists. The visual degree of hepatic steatosis in all study subjects was graded on a 4-point scale by two independent reviewers using gray-scale ultrasonography. Thereafter, the attenuation coefficient (AC) was correlated with the degree of hepatic steatosis using Spearman rank correlation analysis. Intra-class correlation coefficients (ICCs) were used to assess the intra-observer (group 1) and inter-observer reproducibility (group 2) of ATI measurements.

RESULTS

For the intra-observer reproducibility of ATI, the ICC was 0.929 (95% confidence interval [CI], 0.901 to 0.949), and the coefficient of variation was 7.1%. Inter-observer reproducibility of ATI measurements showed an ICC of 0.792 (95% CI, 0.549 to 0.916). The AC showed a significant correlation with the visual grade of hepatic steatosis for both reviewers (rho, 0.780 and 0.695; P<0.001, respectively).

CONCLUSION

ATI showed high intra- and inter-observer reproducibility in the assessment of hepatic steatosis.

Nonalcoholic Fatty Liver Disease and Sarcopenia Are Independently Associated With Cardiovascular Risk

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) and sarcopenia have a close association with an increased risk of atherosclerotic cardiovascular disease (ASCVD). This study investigated the influence of NAFLD and sarcopenia on ASCVD risk.

METHODS

Data from the 2008-2011 Korean National Health and Nutrition Examination Surveys database were analyzed (n = 7,191). The sarcopenia index was calculated using dual-energy x-ray absorptiometry. Sarcopenia was defined as the lowest quintile sarcopenia index value (cutoffs = 0.882 for men and 0.582 for women). NAFLD was defined as a comprehensive NAFLD score ≥40. Liver fibrosis was assessed using the fibrosis-4 (FIB-4) index. ASCVD risk was evaluated using American College of Cardiology/American Heart Association guidelines. High probability of ASCVD was defined as ASCVD risk >10%.

RESULTS

The prevalence rates of NAFLD and sarcopenia were 31.2% (n = 2,241) and 19.5% (n = 1,400), respectively. The quartile-stratified ASCVD risk scores were positively associated with NAFLD and sarcopenia (all P for trend < 0.001). Subjects with both NAFLD and sarcopenia had a higher risk for high probability of ASCVD (odds ratio = 1.83, P = 0.014) compared with controls without NAFLD and sarcopenia. Among subjects with NAFLD, FIB-4-defined significant liver fibrosis and sarcopenia additively raised the risk for high probability of ASCVD (odds ratio = 3.56, P < 0.001) compared with controls without FIB-4-defined significant liver fibrosis or sarcopenia.

DISCUSSION

NAFLD and sarcopenia were significantly associated with an increased risk of ASCVD in the general population. In addition, NAFLD with significant liver fibrosis and sarcopenia were significantly associated with an increased risk of ASCVD in subjects with NAFLD.

Quantitative ultrasound approaches for diagnosis and monitoring hepatic steatosis in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is a major global health concern with increasing prevalence, associated with obesity and metabolic syndrome. Recently, quantitative ultrasound-based imaging techniques have dramatically improved the ability of ultrasound to detect and quantify hepatic steatosis. These newer ultrasound techniques possess many inherent advantages similar to conventional ultrasound such as universal availability, real-time capability, and relatively low cost along with quantitative rather than a qualitative assessment of liver fat. In addition, quantitative ultrasound-based imaging techniques are less operator dependent than traditional ultrasound. Here we review several different emerging quantitative ultrasound-based approaches used for detection and quantification of hepatic steatosis in patients at risk for nonalcoholic fatty liver disease. We also briefly summarize other clinically available imaging modalities for evaluating hepatic steatosis such as MRI, CT, and serum analysis.

Hepatic FATP5 expression is associated with histological progression and loss of hepatic fat in NAFLD patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are characterized by the accumulation of excess hepatic fat. However, in the progression from NASH to cirrhosis, hepatic fat is often lost. Our aim was to elucidate the mechanism underlying hepatic fat loss during NASH progression.

METHODS

Liver biopsies were performed at The University of Tokyo Hospital between November 2011 and March 2016 on 146 patients with NAFLD and 14 patients with cryptogenic cirrhosis who were not being treated with any diabetes or dyslipidemia drugs. Among them, 70 patients underwent liver biopsy after an overnight fast, and 90 patients were biopsied 5 h after an oral glucose tolerance test. Expression differences in genes encoding several fatty acid metabolism-related factors were examined and correlated with hepatic histological changes based on NAFLD activity scores. Prospective patient follow-up continued until June 2018.

RESULTS

The level of fatty acid transport protein 5 (FATP5), which is associated with free fatty acid intake, was significantly and inversely correlated with features of histological progression, including ballooning and fibrosis. This was confirmed by immunohistochemical analysis. Transcript levels of genes encoding fatty acid metabolism-related proteins were comparable between NASH with severe fibrosis and cryptogenic cirrhosis. Furthermore, a prospective cohort study demonstrated that low FATP5 expression was the most significant risk factor for hepatic fat loss.

CONCLUSIONS

Decreased hepatic FATP5 expression in NAFLD is linked to histological progression, and may be associated with hepatic fat loss during NASH progression to cirrhosis.

Performance of Controlled Attenuation Parameter in Patients with Advanced Chronic Liver Disease and Portal Hypertension

BACKGROUND

Liver stiffness (LS) measured by vibration-controlled transient elastography (VCTE) is influenced by liver fibrosis and hepatic perfusion pressure. VCTE-based controlled attenuation parameter (CAP) is a noninvasive marker for hepatic steatosis (HS).

AIMS

To investigate the diagnostic performance of CAP in patients with advanced chronic liver disease (ACLD)/portal hypertension (PHT: hepatic venous pressure gradient (HVPG) ≥ 6 mmHg).

METHODS

Eighty-eight patients with LS ≥ 10 kPa and/or HVPG ≥ 6 mmHg who underwent simultaneous liver biopsy, CAP, and HVPG measurement were included. HS was histologically graded according to the modified Brunt classification.

RESULTS

Patient characteristics: Mean MELD:11 (standard derivation [SD] ± 4), median HVPG:16 (interquartile range [IQR]10-19) mmHg, median LS:27.4 (IQR 16.2-48.9) kPa, and mean CAP:221 (SD ± 75) dB/m. According to histology, 47 (53.4%) patients had no HS (S0), 28 (31.8%) had S1, 11 (12.5%) had S2, and 2 (2.3%) had S3. The area under the receiver operating characteristic curve (AUROC) of CAP for diagnosing any HS (S0 vs. ≥ S1) was 0.692 (95% confidence interval [95% CI] 0.582-0.802) in the overall cohort, 0.830 (95% CI 0.637-1.0) in patients with HVPG < 10 mmHg, and 0.629 (95% CI 0.497-0.761) in patients with clinically significant portal hypertension (CSPH; HVPG ≥ 10 mmHg; n = 69). Using the established cutoff for any HS (248 dB/m), the sensitivity/specificity of CAP was only 48.8%/76.6%, respectively. In contrast, the AUROC and sensitivity/specificity (cutoff 268 dB/m) for diagnosing HS ≥ S2 were 0.842 (95% CI 0.747-0.936) and 84.6%/81.3%, respectively. CAP correlated with the percentage of steatotic hepatocytes (Spearman's ρ = 0.402; p ≤ 0.001) and showed a weak correlation with liver stiffness (ρ = 0.225; p = 0.035).

CONCLUSIONS

The diagnostic performance of CAP for any HS seems to be limited in patients with ACLD, if CSPH is present.

Application of transient elastography in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Although it has become one of the leading causes of cirrhosis and hepatocellular carcinoma in the Western world, the proportion of NAFLD patients developing these complications is rather small. Therefore, current guidelines recommend non-invasive tests for the initial assessment of NAFLD. Among the available non-invasive tests, transient elastography by FibroScan^® (Echosens, Paris, France) is commonly used by hepatologists in Europe and Asia, and the machine has been introduced to the United States in 2013 with rapid adoption. Transient elastography measures liver stiffness and the controlled attenuation parameter simultaneously and can serve as a one-stop examination for both liver steatosis and fibrosis. Liver stiffness measurement also correlates with clinical outcomes and can be used to select patients for varices screening. Although obesity is a common reason for measurement failures, the development of the XL probe allows successful measurements in the majority of obese patients. This article reviews the performance and limitations of transient elastography in NAFLD and highlights its clinical applications. We also discuss the reliability criteria for transient elastography examination and factors associated with false-positive liver stiffness measurements.

Accuracy of imaging methods for steatohepatitis diagnosis in non-alcoholic fatty liver disease patients: A systematic review

BACKGROUND & AIMS

Non-invasive tests to diagnose non-alcoholic steatohepatitis (NASH) are urgently needed. This systematic review aims to evaluate imaging accuracy in diagnosing NASH among non-alcoholic fatty liver disease (NAFLD) patients, using liver biopsy as reference.

METHODS

Eligible studies were systematic reviews and cross-sectional/cohort studies of NAFLD patients comparing imaging with histology, considering accuracy and/or associations. MEDLINE, Scopus, EMBASE and Cochrane Library databases were searched up to April 2018. Studies were screened on title/abstract, then assessed for eligibility on full-text. Data were extracted using a predesigned form. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Of the 641 studies screened, 61 were included in scoping review, 30 of which (with accuracy results) in data synthesis. Imaging techniques included: elastography (transient elastography-TE, acoustic radiation force impulse-ARFI, magnetic resonance elastography-MRE), ultrasound (US), magnetic resonance (MR), computed tomography and scintigraphy. Histological NASH definition was heterogeneous. In 28/30 studies, no prespecified threshold was used (high risk of bias). AUROCs were up to 0.82 for TE, 0.90 for ARFI, 0.93 for MRE and 0.82 for US scores. MR techniques with higher accuracy were spectroscopy (AUROC = 1 for alanine), susceptibility-weighted imaging (AUROC = 0.91), multiparametric MR (AUROC = 0.80), optical analysis (AUROC = 0.83), gadoxetic acid-enhanced MR (AUROCs = 0.85) and superparamagnetic iron oxide-enhanced MR (AUROC = 0.87). Results derived mostly from single studies without independent prospective validation.

CONCLUSIONS

There is currently insufficient evidence to support the use of imaging to diagnose NASH. More studies are needed on US and MR elastography and non-elastographic techniques, to date the most promising methods.

Practical Use of Transient Elastography in Screening for Nonalcoholic Steatohepatitis in a Japanese Population

Background and Aims: Fatty infiltration of liver may induce insulin resistance (IR), and a proportion of patients with nonalcoholic fatty liver disease (NAFLD) is diagnosed with nonalcoholic steatohepatitis. Transient elastography is gaining popularity as a means of non-invasively determining both liver stiffness (fibrosis level) and degree of fatty infiltration, expressed as controlled attenuation parameter (CAP) value. Methods: The aims of this study were to investigate the association between IR and level of fatty liver, and to identify the group at a greater risk of nonalcoholic steatohepatitis using transient elastography and other noninvasive fibrosis markers. A total of 169 patients without chronic hepatitis B and C were analyzed. Results: The CAP value was significantly associated with IR (HOMA-IR ≥2.5; AUROC = 0.81), and the optimal cut-off to discriminate IR was 264 dB/m. The liver stiffness measurement and aspartate aminotransferase-to-platelet ratio index values were significantly higher for CAP ≥264 than in CAP <264. The 9 patients among the overall 169 patients (5.3%) and among the 102 NAFLD patients (8.8%) who showed ≥264 dB and ≥7.0 kPa in transient elastography could represent good candidates for liver biopsy. Conclusions: Evaluation of NAFLD based on CAP values was useful in diagnosing IR. About 9% of NAFLD patients in a Japanese outpatient clinic with a few metabolic complications might be considered good candidates for liver biopsy to confirm nonalcoholic steatohepatitis.

Diagnostic accuracy of controlled attenuation parameter (CAP) as a non-invasive test for steatosis in suspected non-alcoholic fatty liver disease: a systematic review and meta-analysis

Background

Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing hepatic steatosis. Despite good diagnostic performance, clinical application of CAP is limited due to the influences of covariates. Here, a systematic review on the performance of CAP in the diagnosis and staging of hepatic steatosis in NAFLD patients was performed.

Methods

The sensitivity, specificity, diagnostic odds ratio (DOR) and area under receiver operating characteristics (AUROC) curves of the pooled data for CAP in diagnosing and staging the mild (Stage 1), moderate (Stage 2) and severe (Stage 3) steatosis in NAFLD patients were assessed. The clinical utility of CAP was evaluated by Fagan plot. Heterogeneity was explored using subgroup analysis.

Results

Nine studies involving 1297 patients with liver biopsy-proven NAFLD were analyzed. The pooled sensitivity of CAP in detecting mild hepatic steatosis was 87% with a specificity of 91% and a DOR of 84.35. The pooled sensitivity of CAP in detecting moderate hepatic steatosis was 85% with a specificity of 74% and a DOR of 21.28. For severe steatosis, the pooled sensitivity was 76% with a specificity of 58% and a DOR of 4.70. The mean AUROC value for CAP in the diagnosis of mild, moderate, and severe steatosis was 0.96, 0.82 and 0.70, respectively. A subgroup analysis indicated that variation in the geographic regions, cutoffs, age and body mass index (BMI) could be the potential sources of heterogeneity in the diagnosis of moderate to severe steatosis.

Conclusions

CAP should be cautiously considered as a non-invasive substitute for liver biopsy in clinical practice.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-0961-9) contains supplementary material, which is available to authorized users.

The role of Small Intestinal Bacterial Overgrowth (SIBO) in Non-alcoholic Fatty Liver Disease (NAFLD) patients evaluated using Controlled Attenuation Parameter (CAP) Transient Elastography (TE): a tertiary referral center experience

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an emerging disease, where it can progress to non-alcoholic steatohepatitis (NASH) and lead to liver cirrhosis or liver cancer. Small intestinal bacterial overgrowth (SIBO) has been hypothesized to play an important role in NAFLD development and progression, however, there is still conflicting data about this phenomenon. Transient Elastography (TE) examination using controlled attenuation parameter (CAP) has been validated for liver disease progression assessment in NAFLD. It is non-invasive method and easy to perform in clinical practice. Therefore, we would like to know the role of SIBO in NAFLD and its possible impact on disease progression.

METHODS

A cross-sectional design study performed at outpatient's Hepatobiliary clinic at tertiary referral university hospital in Jakarta. All recruited study subjects based on inclusions criteria underwent laboratory examination, transabdominal ultrasound examination, CAP-TE 502 (by Echosens, France), and glucose hydrogen breath test (GHBT) using portable hydrogen breath test apparatus (Gastro+™ Gastrolyzer by Bedfont Scientific Ltd). Stool sample examination was performed using RT-PCR.

RESULTS

This study recruited 160 subjects with median age of 58 (22-78) years and 108 (67.5%) of them are female. SIBO (65,5%), DM (70.8%), dyslipidemia (75.2%), obesity (76.6%), and metabolic syndrome (73%) were more prevalent in NAFLD than non-NAFLD population. Bivariate analysis showed no significant association between SIBO and NAFLD development (p = 0.191; PR 0.871; CI 95% [0.306-1.269]). SIBO was also not associated with significant hepatic steatosis (p = 0.951; PR = 0.951; CI 95% [0.452-2.239]) and fibrosis (p = 0.371; PR = 1.369; CI 95% [0.608-3.772]). However, the presence of central obesity has significantly associated with the presence of SIBO (p = 0.001; PR = 0.378; CI 95% [0.021-0.478]). Based on stool sample analysis from 60 NAFLD patients, there is a significant correlation using Spearmen test between the presence of Bacteroides and the stage of fibrosis (p .037). Further analysis between obese NAFLD patients and non-obese NAFLD patients showing that there is a significant decrease of Bifidobacteria (p .047) and Lactobacillus (p .038) in obese NAFLD patients and a tendency of increase Bacteroides in obese NAFLD patients (p .572).

CONCLUSIONS

SIBO is not associated with NAFLD development and progression.

Quantitative Hepatic Fat Quantification in Non-alcoholic Fatty Liver Disease Using Ultrasound-Based Techniques: A Review of Literature and Their Diagnostic Performance

Non-alcoholic fatty liver disease is a condition that is characterized by the presence of >5% fat in the liver and affects more than one billion people worldwide. If adequate and early precautions are not taken, non-alcoholic fatty liver disease can progress to cirrhosis and death. The current reference standard for detecting hepatic steatosis is a liver biopsy. However, because of the potential morbidity associated with liver biopsies, non-invasive imaging biomarkers have been extensively investigated. Magnetic resonance imaging-based methods have proven accuracy in quantifying liver steatosis; however, these techniques are costly and have limited availability. Ultrasound-based quantitative imaging techniques are increasingly utilized because of their widespread availability, ease of use and relative cost-effectiveness. Several ultrasound-based liver fat quantification techniques have been investigated, including techniques that measure changes in the acoustic properties of the liver caused by the presence of fat. In this review, we focus on quantitative ultrasound approaches and their diagnostic performance in the realm of non-alcoholic fatty liver disease.

Current status of imaging in nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common diffuse liver disease, with a worldwide prevalence of 20% to 46%. NAFLD can be subdivided into simple steatosis and nonalcoholic steatohepatitis. Most cases of simple steatosis are non-progressive, whereas nonalcoholic steatohepatitis may result in chronic liver injury and progressive fibrosis in a significant minority. Effective risk stratification and management of NAFLD requires evaluation of hepatic parenchymal fat, fibrosis, and inflammation. Liver biopsy remains the current gold standard; however, non-invasive imaging methods are rapidly evolving and may replace biopsy in some circumstances. These methods include well-established techniques, such as conventional ultrasonography, computed tomography, and magnetic resonance imaging and newer imaging technologies, such as ultrasound elastography, quantitative ultrasound techniques, magnetic resonance elastography, and magnetic resonance-based fat quantitation techniques. The aim of this article is to review the current status of imaging methods for NAFLD risk stratification and management, including their diagnostic accuracy, limitations, and practical applicability.

Case definitions for inclusion and analysis of endpoints in clinical trials for nonalcoholic steatohepatitis through the lens of regulatory science

Nonalcoholic steatohepatitis (NASH) is an important cause of liver-related morbidity and mortality. There are no approved therapies, and the results of clinical trials have been difficult to compare due to inconsistent definitions of relevant disease parameters in patients with NASH. The natural course of the disease has not been rigorously characterized, particularly with respect to the contributions of underlying obesity, type 2 diabetes, and other comorbidities and the treatments provided for these comorbidities. Efforts to perform analyses of pooled data are limited by heterogeneous case definitions used across studies to define disease states. There remains a major unmet need in the field to develop standardized definitions for populations for interventional trials. Such definitions are expected to impact how endpoints for clinical trials are constructed. The Liver Forum is a multistakeholder effort including US and European regulatory agencies, academic investigators, professional and patient representative organizations, and industry to catalyze therapeutic development for NASH by developing potential solutions to barriers to development. The Case Definitions Working Group was established by The Liver Forum to evaluate the validity of case definitions for populations to be included in clinical trials for NASH from a regulatory science perspective. Based on such analyses, specific recommendations are provided noting the strengths and weaknesses of the case definitions along with knowledge gaps that require additional study. (Hepatology 2018;67:2001-2012).

Performance characteristics of vibration-controlled transient elastography for evaluation of nonalcoholic fatty liver disease

Vibration-controlled transient elastography estimates liver stiffness measurement (LSM) and controlled attenuation parameter (CAP), which are noninvasive assessments of hepatic fibrosis and steatosis, respectively. However, prior vibration-controlled transient elastography studies reported high failure rates in patients with nonalcoholic fatty liver disease. We examined the performance characteristics of the FibroScan 502 Touch with two probes, medium (M+) and extra large (XL+), in patients with nonalcoholic fatty liver disease in a multicenter setting. A total of 1,696 exams were attempted in 992 patients (body mass index, 33.6 ± 6.5 kg/m2 ) with histologically confirmed nonalcoholic fatty liver disease. Simultaneous assessment of LSM and CAP was performed using the FibroScan 502 Touch with an automatic probe selection tool. Testing was conducted twice in patients by either a single operator (87%) or two operators (13%). Failure was defined as the inability to obtain a valid examination. An examination was considered unreliable if LSM interquartile range/median was >30%. Significant disagreement between two readings was defined as >95% limits of agreement between two readings. A total of 1,641 examinations yielded valid results with a failure rate of 3.2% (55/1,696). The proportion of unreliable scans for LSM was 3.9%. The proportion of unreliable scans with operator experience in the top quartile (≥59 procedures) was significantly lower than that in the lower three quarters combined (1.6% versus 4.7%, P = 0.02 by Fisher's exact test). The significant disagreement between first and second readings for LSM and CAP when obtained back to back was 18% and 11%, respectively.

CONCLUSION

Vibration-controlled transient elastography for estimation of LSM and CAP can be successfully deployed in a multicenter setting with low failure (3.2%) and high reliability (>95%) rates and high reproducibility. (Hepatology 2018;67:134-144).

The relationship between visceral obesity and hepatic steatosis measured by controlled attenuation parameter

Background

Nonalcoholic fatty liver disease (NAFLD) is closely related with obesity. However, obese subjects, generally represented by high BMI, do not always develop NAFLD. A number of possible causes of NAFLD have been studied, but the exact mechanism has not yet been elucidated.

Methods

A total of 304 consecutive subjects who underwent general health examinations including abdominal ultrasonography, transient elastography and abdominal fat computed tomography were prospectively enrolled. Significant steatosis was diagnosed by ultrasonography and controlled attenuation parameter (CAP) assessed by transient elastography.

Results

Visceral fat area (VFA) was significantly related to hepatic steatosis assessed by CAP, whereas body mass index (BMI) was related to CAP only in univariate analysis. In multiple logistic regression analysis, VFA (odds ratio [OR], 1.010; 95% confidence interval [CI], 1.001–1.019; P = 0.028) and triglycerides (TG) (OR, 1.006; 95% CI, 1.001–1.011; P = 0.022) were independent risk factors for significant hepatic steatosis. The risk of significant hepatic steatosis was higher in patients with higher VFA: the OR was 4.838 (P<0.001; 95% CI, 2.912–8.039) for 100<VFA≤200 cm² and 7.474 (P<0.001; 95% CI, 2.462–22.693) for VFA >200 cm², compared to patients with a VFA ≤100 cm².

Conclusions

Our data demonstrated that VFA and TG is significantly related to hepatic steatosis assessed by CAP not BMI. This finding suggests that surveillance for subjects with NAFLD should incorporate an indicator of visceral obesity, and not simply rely on BMI.

Utility of transient elastography (fibroscan) and impact of bariatric surgery on nonalcoholic fatty liver disease (NAFLD) in morbidly obese patients

BACKGROUND

Controlled attenuation parameter (CAP) is a novel, noninvasive technique for assessing hepatic steatosis. However, its role in morbidly obese individuals is unclear. The effect of bariatric surgery on inflammation and fibrosis needs to be explored.

OBJECTIVES

To assess the utility of CAP for assessment of hepatic steatosis in morbidly obese individuals and evaluate the effect of bariatric surgery on hepatic steatosis and fibrosis.

SETTING

A tertiary care academic hospital.

METHODS

Baseline details of anthropometric data, laboratory parameters, FibroScan (XL probe), and liver biopsy were collected. Follow-up liver biopsy was done at 1 year.

RESULTS

Of the 124 patients screened, 76 patients were included; mean body mass index was 45.2 ± 7.1 kg/m². FibroScan success rate was 87.9%. The median liver stiffness measurement (LSM) and CAP were 7.0 (5.0-9.5) kPa and 326.5 (301-360.5) dB/m, respectively. On liver histopathology, severe steatosis and nonalcoholic steatohepatitis were present in 5.3% and 15.8%; significant fibrosis (≥stage 2) and cirrhosis in 39.5% and 2.6%, respectively. Area under receiver operator characteristic curve of LSM for prediction of significant fibrosis (F2-4 versus F0-1) and advanced fibrosis (F3-4 versus F0-2) was .65 (95% confidence interval [CI]: .52-.77) and .83 (95% CI: .72-.94), respectively. The area under receiver operator characteristic curve of CAP for differentiating moderate hepatic steatosis (S2-3 versus S0-1) and severe hepatic steatosis (S3 versus S0-2) was .74 (95% CI: .62-.86) and .82 (95% CI: .73-.91), respectively. At 1-year follow-up, 32 patients underwent liver biopsy. In these patients, there was significant improvement in hepatic steatosis (P = .001), lobular inflammation (P = .033), ballooning (P<.001), and fibrosis (P = .003). Nonalcoholic steatohepatitis was resolved in 3 of 4 (75%) patients. LSM and CAP significantly declined.

CONCLUSIONS

LSM and CAP are feasible and accurate at diagnosing advanced fibrosis and severe hepatic steatosis in morbidly obese individuals. Bariatric surgery is associated with significant improvement in LSM, CAP, steatohepatitis, and fibrosis.

A prospective comparative assessment of the accuracy of the FibroScan in evaluating liver steatosis

Background/aims

Recent studies have demonstrated the utility of the FibroScan^® device in diagnosing liver steatosis, but its usefulness has not been thoroughly appraised. We investigated the usefulness of the controlled attenuation parameter (CAP) in detecting and quantifying liver steatosis.

Methods

A prospective analysis was applied to 79 chronic liver disease patients who underwent a liver biopsy, a FibroScan investigation, ultrasonography, and hepatic steatosis index (HSI). The presence and degree of steatosis as measured by the FibroScan device, ultrasonography and HSI were compared with the results for the liver biopsy tissue.

Results

There was substantial concordance between the liver biopsy results and the CAP as evaluated by the kappa (κ) index test for detecting liver steatosis (κ_CAP = 0.77, P<0.001; κ_{ultrasonography} = 0.60, P<0.001; κ_HSI = 0.47, P<0.001). The areas under the receiver operating characteristic curve (AUROCs) of the CAP, ultrasonography, and HSI were 0.899 [95% confidence interval (CI) = 0.826–0.972)], 0.859 (95% CI = 0.779–0.939), and 0.766 (95% CI = 0.655–0.877), respectively. The optimal CAP cutoff value for differentiating between normal and hepatic steatosis was 247 dB/m, which produced sensitivity and specificity values of 91.9% and 85.7%, respectively, as well as a positive predictive value of 85.0% and a negative predictive value of 92.3%.

Conclusion

The CAP produces results that are highly concordant with those of a liver biopsy in detecting steatosis. Therefore, the CAP is a noninvasive and reliable tool for evaluating liver steatosis, even in the early stages.

Prevalence and Predictors of Significant Fibrosis Among Subjects with Transient Elastography-Defined Nonalcoholic Fatty Liver Disease

BACKGROUND/AIMS

Transient elastography (TE) can be used to assess the degree of liver fibrosis and steatosis. We investigated the prevalence and predictors of nonalcoholic fatty liver disease (NAFLD) with or without significant liver fibrosis in the general population.

METHODS

A total of 3033 subjects without alcoholic or chronic viral liver diseases who underwent a medical health check-up including TE were recruited from April 2013 to August 2014. TE-defined NAFLD was defined as a controlled attenuation parameter of ≥250 dB/m, and significant liver fibrosis was defined as a liver stiffness (LS) value of ≥8 kPa.

RESULTS

Overall, 1178 (42.9%) subjects had NAFLD. Subjects with NAFLD had significantly higher alanine aminotransferase (ALT) levels and a higher prevalence of parameters related to metabolic syndrome, such as high blood pressure, a high body mass index (BMI), glucose intolerance, and dyslipidemia than did subjects without NAFLD (all P < 0.05). Age, male gender, ALT level, serum albumin, BMI, diabetes, hypertriglyceridemia, and LS values independently showed positive associations with the presence of NAFLD (all P < 0.05). In addition, concomitant significant liver fibrosis was identified in 60 (5.1%) subjects with NAFLD, and its independent predictors were age [odds ratio (OR) 1.054], ALT level (OR 1.019), BMI (OR 1.217), and diabetes (OR 1.987) (all P < 0.05).

CONCLUSIONS

We found that the prevalence of subjects with NAFLD was high (42.9%), and 5.1% of them had concomitant significant liver fibrosis. The risk factors found in this study can help identify which subjects with NAFLD are vulnerable to fibrosis progression.