Noninvasive evaluation of NAFLD

Ethnic influence on nonalcoholic fatty liver disease prevalence and lack of disease awareness in the United States, 2011-2016

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a rising global disease associated with clinical and economic burdens.

OBJECTIVES

We aimed to quantify NAFLD prevalence and awareness to provide stakeholders necessary information to combat NAFLD burden.

METHODS

This study utilizes data from the National Health and Nutrition Examination Survey 2011-2016 and included 4538 adult participants who did not have heavy drinking or viral hepatitis history. The US fatty liver index defined NAFLD and NAFLD fibrosis score defined fibrosis. NAFLD awareness was captured by questionnaire.

RESULTS

Amongst the study population of 4538 persons, NAFLD prevalence was 32.5%, lowest in non-Hispanic Blacks (18.0%) and Asians (18.1%), highest amongst Mexican Americans (48.4%). Within the NAFLD group, advanced fibrosis was highest in non-Hispanic Blacks (28.5%) and lowest amongst non-Hispanic Asians (2.7%). Of the 1473 (97.5%) NAFLD participants who answered NAFLD awareness question, 90% visited a healthcare centre at least once in the past year, but only 5.1% were aware of having NAFLD. On weighted population estimates, 77.33 million persons had NAFLD, 17.63 million had advanced fibrosis, and 73.39 million NAFLD participants were not aware of having NAFLD.

CONCLUSIONS

Of 77.33 million people in the United States have NAFLD with 17.63 million having advanced fibrosis, with lowest prevalence in non-Hispanic Asians and highest in Mexican Americans. A conundrum exists amongst non-Hispanic Blacks who have low NAFLD prevalence but highest prevalence of advanced fibrosis. Awareness of NAFLD was low across all ethnicities. Effort is needed to improve disease awareness whilst addressing NAFLD clinical burden across ethnicities.

Noninvasive Serum Fibrosis Markers are Associated with Coronary Artery Calcification in Patients with Nonalcoholic Fatty Liver Disease

Background/Aims

Advanced hepatic fibrosis is associated with cardiovascular disease (CVD) in patients with nonalcoholic fatty liver disease (NAFLD). We investigated the association between noninvasive serum fibrosis markers and the coronary artery calcium score (CACS) in subjects with NAFLD.

Methods

We analyzed 665 NAFLD subjects without chronic liver disease or heart disease between 2011 and 2015. The noninvasive fibrosis markers that were used to evaluate the severity of hepatic fibrosis included the NAFLD fibrosis score (NFS), fibrosis-4 (FIB-4) score, Forn's index, and the aspartate aminotransferase to platelet ratio index (APRI).

Results

The areas under the receiver operating characteristics curves for the NFS, FIB-4 score, Forn's index and APRI for predicting CACS >100 were 0.689, 0.683, 0.659, and 0.595, respectively. According to the multivariate analysis, older age, increased body mass index (BMI), and decreased estimated glomerular filtration rate (eGFR) were significant factors associated with CACS >100. The NFS, FIB-4 score and APRI were significantly associated with CACS >100 after adjusting for age and gender (p=0.006, p=0.012, and p=0.012, respectively) and after adjusting for age, gender, BMI and eGFR (p=0.013, p=0.022, and p=0.027, respectively). Scores integrating noninvasive fibrosis markers and other risk factors improved the predictive accuracy.

Conclusions

The NFS and FIB-4 score were associated with coronary atherosclerosis in subjects with NAFLD. Furthermore, scores integrating these noninvasive scores and risk factors for CVD showed good discriminatory power in predicting CACS >100. Therefore, noninvasive serum fibrosis markers may be useful tools for identifying NAFLD subjects at a high risk for CVD.

Evaluation of the effectiveness of ultrasound shear elastography and liver steatometry

Detection of liver fibrosis and steatosis at early stages is a difficult task for clinical practice, due to the lack of early signs in routine radiation diagnostics. Aim. To evaluate the efficacy of ultrasound shear elastography and ultrasound steatometry of the liver with the use of domestic ultrasonic diagnostic system Angiodin-Sono/N-Ultra. Materials and methods. 264 people held ultrasound elastography and ultrasound steatometry. 38 patients underwent percutaneous puncture liver biopsy and subsequent pathophysiological examination. Results. High correlation of fibrosis obtained at the Angiodin-Sono/N-Ultra and the leading ultrasonic systems with shear elastography was revealed. Cross-sectional comparative analysis of elasticity with the results of liver steatometry was conducted. Conclusions. Results obtained in all groups correlate with the data obtained in studies on Fibroscan. When working with system Angiodin we got a simultaneous comparative analysis of elasticity with the results of liver steatosis. Results appear to be much more stable and compact than those obtained in studies on the Fibroscan. A new diagnostic criterion was revealed the phenomenon of independence of fibrosis and steatosis indices.

Injectable Biomedical Devices for Sensing and Stimulating Internal Body Organs

The rapid pace of progress in implantable electronics driven by novel technology has created devices with unconventional designs and features to reduce invasiveness and establish new sensing and stimulating techniques. Among the designs, injectable forms of biomedical electronics are explored for accurate and safe targeting of deep-seated body organs. Here, the classes of biomedical electronics and tools that have high aspect ratio structures designed to be injected or inserted into internal organs for minimally invasive monitoring and therapy are reviewed. Compared with devices in bulky or planar formats, the long shaft-like forms of implantable devices are easily placed in the organs with minimized outward protrusions via injection or insertion processes. Adding flexibility to the devices also enables effortless insertions through complex biological cavities, such as the cochlea, and enhances chronic reliability by complying with natural body movements, such as the heartbeat. Diverse types of such injectable implants developed for different organs are reviewed and the electronic, optoelectronic, piezoelectric, and microfluidic devices that enable stimulations and measurements of site-specific regions in the body are discussed. Noninvasive penetration strategies to deliver the miniscule devices are also considered. Finally, the challenges and future directions associated with deep body biomedical electronics are explained.

Prospective evaluation of non-alcoholic fatty liver disease by elastographic methods of liver steatosis and fibrosis; controlled attenuation parameter and liver stiffness measurements

AIMS

To examine the temporal changes of both controlled attenuation parameter (CAP) and liver stiffness measurements (LSM), assessed by Fibroscan, in a large sample of patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

In this prospective, observational study, we consecutively enrolled 507 adult individuals with Fibroscan-defined NAFLD who were followed for a mean period of 21.2 ± 11.7 months.

RESULTS

During the follow-up period, 84 patients (16.5%) had a progression of CAP of at least 20% with a median time of 39.93 months, while 201 (39.6%) patients had a progression of LSM of at least 20% with median time of 30.46 months. There were significant differences in the proportion of LSM progression across body mass index (BMI) categories, with obese patients having the highest risk of progression over the follow-up (hazard ratio 1.66; 95%CI 1.23-2.25). Multivariable regression analysis showed that BMI and serum creatinine levels were the strongest predictors for CAP progression in the whole population, while HOMA-estimated insulin resistance was an independent predictor of LSM progression over time in the subgroup of obese patients.

CONCLUSION

This prospective study shows for the first time that the progression risk of both liver steatosis and fibrosis, detected non-invasively by Fibroscan, is relevant and shares essentially the same metabolic risk factors that are associated with NAFLD progression detected by other invasive methods.

Noninvasive diagnosis in alcohol-related liver disease

Background

Alcohol‐related liver disease (ALD) represents a major cause of death worldwide, and unfortunately, most patients are diagnosed at an advanced stage of the disease, which is related to poorer outcomes. Liver biopsy has historically been the gold standard for identifying advanced hepatic fibrosis, but this approach has several limitations, including invasiveness, low applicability, sampling variability, and cost.

Main Text

In order to detect earlier features of advanced liver fibrosis, surrogate biomarkers and techniques have been developed. While these were initially developed for chronic liver diseases such as viral hepatitis and nonalcoholic fatty liver disease (NAFLD), their performance in ALD has also been recently studied. Among the noninvasive surrogate markers and techniques used to detect liver fibrosis, the Enhanced Liver Fibrosis test, FibroTest, and Transient Elastography are the most accurate and validated techniques. In this review, we summarize the current status of the noninvasive assessment of liver disease in ALD and provide a synthesis of how these noninvasive tools can be used in clinical practice. Finally, we briefly outline novel biomarkers that are currently being investigated and discuss future directions and new opportunities in the noninvasive diagnosis of ALD.

Effects of Simvastatin on the Metabolism of Fatty Acids in Combined Secondary Prevention of Coronary Heart Disease: Dosage and Gender Differences between the Effects

BACKGROUND

Statins are currently used for secondary prevention of Coronary Heart Disease (CHD), as the lipid-lowering therapy with them is proven safe and effective.

OBJECTIVE

The purpose of this research is to investigate the dose-dependent effect of statins used for secondary prevention of coronary heart disease, as well as mechanisms of quantitative and qualitative changes in lipoproteins, fatty acids and cholesterol in the blood and tissues of people of both sexes.

METHODS

In a clinical trial (n=125, of which 89 patients belong to group 1 and 36 to group 2) and an experiment on laboratory animals (n = 100), simvastatin reduced the total level of fatty acids in blood plasma, when given in the amount that was within the therapeutic dose range.

RESULTS

This effect was achieved through a drug-induced improvement in the capacity of hepatic cells to absorb Low-density (LDL) and Very-low-density (VLDL) lipoproteins.

CONCLUSION

Considering the formation of saturated fatty acids, statin performed better in males. With Omega-3 polyunsaturated fatty acids involved, changes in lipoproteins, cholesterol and fatty acids (liver and myocardium) were similar to those caused by small doses of a statin drug. Effects of the combination of bisoprolol and acetylsalicylic acid were completely different from those caused by the use of statin.

A brief review on the rising incidence of chronic kidney diseases and non-alcoholic fatty liver disease

Chronic kidney diseases (CKDs) are the most common forms of kidney disease all around the world. The incidence of CKD is rising, which is mainly driven by population aging as well as by a global rise in hypertension, metabolic syndrome, and metabolic risk factors, particularly obesity and type-2 diabetes. The high mortality, morbidity of CKD, and the health care costs of the renal replacement therapy have led investigators to seek recent and potentially modifiable risk factors such as non-alcoholic fatty liver disease (NAFLD). NAFLD is the hepatic manifestation of metabolic syndrome and the most common cause of chronic liver disease. It incorporates a spectrum of liver diseases ranging from simple steatosis to steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. On the basis of recent publications, the prevalence of CKD is significantly increased among patients with NAFLD, and the prevalence of NAFLD is also higher in CKD patients than in patients without NAFLD. These findings suggest that patients with NAFLD should be screened for CKD and patients with CKD and metabolic syndrome should be screened for NAFLD. Patients with NAFLD and CKD should be treated and followed up by a multidisciplinary team that involves specialists in hepatology, nephrology, diabetes, and cardiology.

Global Analysis of miRNA Signature Differentially Expressed in Insulin-resistant Human Hepatocellular Carcinoma Cell Line

Chemoresistance mediated by insulin resistance (IR) in HCC has already been validated. However, the underlying mechanism, especially the involvement of microRNAs (miRNAs) was unelucidated. In this study, miRNA microarrays and bioinformatics methods were employed to determine the dysregulation of miRNA by IR in HCC cells, and quantitative RT-PCR (qRT-PCR) was applied to valid the miRNA array data. Of all the 2006 miRNAs screened, 32 miRNAs were found up or down regulated between the HepG2/IR cells and its parental cells. Further literature mining revealed that some of these miRNAs may function as oncogenes or tumor suppressors that contribute to tumor progression, recurrence, and metastasis which eventually lead to chemotherapeutic resistance. Interestingly, bioinformatics analysis by Gene Ontology (GO) enrichment pathway indicating that function of the predicted target genes of these dysregulated miRNAs were significantly enriched in the processes related with biosynthesis, catabolism, modification etc., and Kyoto Encyclopedia of Genes and Genomes (KEGG) mapping showed that the biological regulatory mechanisms were integrated in cancer-related pathways. Moreover, we also constructed a network which connected the differentially expressed miRNAs to target genes, GO enrichments and KEGG pathways to reveal the hub miRNAs, genes and pathways. Collectively, our present study demonstrated the possible miRNAs and predicted target genes involving in the pathophysiology of insulin resistant HCC, providing novel insights into the molecular mechanisms of multidrug resistance in the insulin resistant HepG2 cells.

Prediction of Liver Steatosis Applying a New Score in Subjects from the Brazilian Longitudinal Study of Adult Health

GOALS

To develop a noninvasive algorithm for diagnosis of liver steatosis and to compare its diagnostic value with available predictive models.

BACKGROUND

Liver steatosis represents the most frequent liver disease worldwide.

STUDY

This cross-sectional study analyzed data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Patients were randomly divided into training (n=6571) and validation (n=3286) cohort. Abdominal ultrasound (US), used to grade steatosis, and overnight fasting blood tests were performed at the same day. Fatty Liver Index (FLI), Hepatic Steatosis Index, and Nonalcoholic Fatty Liver Disease-Liver Fat Score were calculated. A backward stepwise multivariate logistic regression analysis was used to develop the new predictive model, Steato-ELSA.

RESULTS

In total, 9857 subjects [58% female, age=51 (interquartile range, 45 to 58) years, body mass index=26.4 (23.9 to 29.6) Kg/m] were included. Body mass index, waist circumference, homeostasis model of assessment of insulin resistance, transaminases, and triglycerides were independently associated with steatosis in the multivariate model (Hosmer-Lemeshow P=0.279). In the validation cohort, the area under the receiver-operator characteristics (95% confidence interval) for prediction of mild and moderate steatosis were: (i) 0.768 (0.751-0.784) and 0.829 (0.810-0.848) for Steato-ELSA; (ii) 0.762 (0.745-0.779) and 0.819 (0.799-0.838) for Fatty Liver Index; (iii) 0.743 (0.727-0.761) and 0.800 (0.779-0.822) for Hepatic Steatosis Index; and (iv) 0.719 (0.701-0.737) and 0.769 (0.747-0.791) for Nonalcoholic Fatty Liver Disease-Liver Fat Score. Steato-ELSA performed significantly better than other models and yielded sensitivity (Se)/specificity (Sp) (95% confidence interval): (i) for mild steatosis (score ≥0.386): Se=65.6% (63.0-68.3) and Sp=73.7% (71.8-75.6); (ii) for moderate steatosis (score ≥0.403): Se=83.5% (80.0-86.9) and Sp=68.7% (67.0-70.4).

CONCLUSIONS

Steato-ELSA is an accurate and inexpensive tool that uses simple parameters to identify individuals at high risk of liver steatosis.

Transient elastography for screening of liver fibrosis: Cost-effectiveness analysis from six prospective cohorts in Europe and Asia

BACKGROUND & AIMS

Non-alcoholic fatty liver disease and alcohol-related liver disease pose an important challenge to current clinical healthcare pathways because of the large number of at-risk patients. Therefore, we aimed to explore the cost-effectiveness of transient elastography (TE) as a screening method to detect liver fibrosis in a primary care pathway.

METHODS

Cost-effectiveness analysis was performed using real-life individual patient data from 6 independent prospective cohorts (5 from Europe and 1 from Asia). A diagnostic algorithm with conditional inference trees was developed to explore the relationships between liver stiffness, socio-demographics, comorbidities, and hepatic fibrosis, the latter assessed by fibrosis scores (FIB-4, NFS) and liver biopsies in a subset of 352 patients. We compared the incremental cost-effectiveness of a screening strategy against standard of care alongside the numbers needed to screen to diagnose a patient with fibrosis stage ≥F2.

RESULTS

The data set encompassed 6,295 participants (mean age 55 ± 12 years, BMI 27 ± 5 kg/m², liver stiffness 5.6 ± 5.0 kPa). A 9.1 kPa TE cut-off provided the best accuracy for the diagnosis of significant fibrosis (≥F2) in general population settings, whereas a threshold of 9.5 kPa was optimal for populations at-risk of alcohol-related liver disease. TE with the proposed cut-offs outperformed fibrosis scores in terms of accuracy. Screening with TE was cost-effective with mean incremental cost-effectiveness ratios ranging from 2,570 €/QALY (95% CI 2,456-2,683) for a population at-risk of alcohol-related liver disease (age ≥45 years) to 6,217 €/QALY (95% CI 5,832-6,601) in the general population. Overall, there was a 12% chance of TE screening being cost saving across countries and populations.

CONCLUSIONS

Screening for liver fibrosis with TE in primary care is a cost-effective intervention for European and Asian populations and may even be cost saving.

LAY SUMMARY

The lack of optimized public health screening strategies for the detection of liver fibrosis in adults without known liver disease presents a major healthcare challenge. Analyses from 6 independent international cohorts, with transient elastography measurements, show that a community-based risk-stratification strategy for alcohol-related and non-alcoholic fatty liver diseases is cost-effective and potentially cost saving for our healthcare systems, as it leads to earlier identification of patients.

Understanding the association of polycystic ovary syndrome and non-alcoholic fatty liver disease

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-age women. Patients with non-alcoholic fatty liver disease (NAFLD) often suffer from metabolic syndrome, atherosclerosis, ischemic heart disease, and extrahepatic tumors, conferring a lower survival than the general population; therefore it is crucial to study the association between NAFLD and PCOS since it remains poorly understood. Insulin resistance (IR) plays a central role in the pathogenesis of NAFLD and PCOS; also, hyperandrogenism enhances IR in these patients. IR, present in the NAFLD-PCOS association could decrease the hepatic production of sex hormone-binding globulin through a possible regulation mediated by hepatocyte nuclear factor 4 alpha. On the other hand, apoptotic processes initiated by androgens actively contribute to the progression of NAFLD. Considering the association between the two conditions, the screening of women with PCOS for the presence of NAFLD appears reasonable. The pathophysiological mechanisms of PCOS-NAFLD association and the initial approach will be reviewed here.

Noninvasive Imaging Modalities in Nonalcoholic Fatty Liver Disease: Where Do We Stand?

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Liver biopsy is the gold standard for diagnosis and staging of fibrosis in patients with NAFLD; however, it is invasive, costly, and may be associated with morbidity and even mortality, so is not suitable for screening the large number of individuals who are at risk of, or have, NAFLD. Therefore, there has been tremendous focus on finding noninvasive diagnostic modalities, including imaging. New imaging modalities are emerging and may potentially replace biopsy. This review discusses the different noninvasive imaging modalities for the assessment of NAFLD.

Non-Alcoholic Fatty Liver Disease is Associated with Higher Metabolic Expenditure in Overweight and Obese Subjects: A Case-Control Study

Non-alcoholic fatty liver disease (NAFLD) is a common condition in Western countries. However, their metabolic characteristics are poorly known even though they could be important. Therefore, the objective of this study was to measure resting metabolic parameters in overweight/obese adults with hepatic steatosis compared to controls, matched for age, sex, and obesity level. Hepatic steatosis was diagnosed with liver ultrasound. Energy metabolism was measured with indirect calorimetry: energy expenditure (REE), predicted REE, the ratio between REE and the predicted REE, and the respiratory quotient (RQ) were reported. We measured some anthropometric, body composition, and bio-humoral parameters; 301 participants with NAFLD were matched for age, sex, and obesity level with 301 participants without NAFLD. People with NAFLD showed significantly higher REE (1523 ± 238 vs. 1464 ± 212 kcal, p = 0.005), REE/REE predicted ratio (98.2 ± 9.4 vs. 95.7 ± 8.1, p = 0.002), and RQ (0.88 ± 0.08 vs. 0.85 ± 0.07, p = 0.03). Moreover, the NAFLD group had significantly higher inflammatory and insulin-resistance parameters compared to controls. In conclusion, NAFLD is associated with a significantly higher metabolic expenditure, as measured with indirect calorimetry, compared to a similar cohort of individuals without this condition. Higher inflammatory levels in patients with NAFLD can probably explain our findings, even if other research is needed on this issue.

Ascorbic acid attenuates cell stress by activating the fibroblast growth factor 21/fibroblast growth factor receptor 2/adiponectin pathway in HepG2 cells

Increasing prevalence of obesity‑induced non‑alcoholic fatty liver disease (NAFLD) and non‑alcoholic steatohepatitis (NASH) has been reported. Ascorbic acid (AA), also known as vitamin C, an excellent antioxidant, has been shown to exert beneficial effects on NAFLD; however, the underlying mechanisms are yet to be fully elucidated. In the present study, the role of AA on cell stress in tumor necrosis factor α (TNFα)‑treated HepG2 cells was investigated. Our findings revealed that exposure to AA effectively ameliorated TNFα‑induced cell stresses, including hypoxia, inflammation and endoplasmic reticulum (ER) stress by reducing the expression of Hif1α and its target genes (glucose transporter 1), pro‑inflammatory genes (monocyte chemoattractant 1) and ER stress‑related genes (glucose‑regulated protein, 78 kDa). AA also decreased the protein level of HIF1α. Additionally, AA significantly increased the secretion of total adiponectin and high molecular weight (HMW) adiponectin. Mechanistically, AA was determined to increase the expression of fibroblast growth factor 21 (FGF21) and its receptor, fibroblast growth factor receptor 2 (FGFR2). Knockdown of FGFR2 not only decreased the levels of total adiponectin and HMW adiponectin, but almost abolished the beneficial effects of AA in ameliorating cell stress. Collectively, the findings of our study demonstrated that AA may attenuate hepatocyte stress induced by TNFα via activation of the FGF21/FGFR2/adiponectin pathway. This could a novel mechanism of action of AA, and its potential for the treatment of NAFLD/NASH.

Prescription of statins in suspected non-alcoholic fatty liver disease and high cardiovascular risk, a population-based study

BACKGROUND & AIMS

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing, with concomitant high incidence of lipoprotein abnormalities. Cardiovascular disease (CVD) is the main cause of death in subjects with NAFLD and management of dyslipidaemia is pivotal for prevention. We aimed to determine cardiovascular risk and indication for statin therapy in subjects with NAFLD.

METHODS

A cross-sectional analysis of the population-based Lifelines Cohort Study of 34 240 adult individuals. Subjects with reported use of lipid-lowering drugs were excluded. Suspected NAFLD was defined as Fatty Liver Index (FLI) ≥60 and advanced hepatic fibrosis as NAFLD fibrosis score (NFS) >0.676. Cardiovascular risk and indication for statin therapy were defined according to the European Society of Cardiology and European Atherosclerosis Society Guideline for the Management of Dyslipidaemias.

RESULTS

FLI ≥ 60 was present in 7067 (20.6%) participants and coincided with increased prevalence of type 2 diabetes mellitus, metabolic syndrome, CVD and impaired renal function (all P < 0.001). 10-year predicted cardiovascular risk was significantly increased in subjects with elevated FLI and NFS (both P < 0.001). Indication for statin use was significantly increased in subjects with FLI ≥ 60 (31.0% vs 15.6%, P < 0.001) and NFS > 0.676 (73.2% vs 30.6%, P < 0.001). In multivariable analyses, FLI ≥ 60 (OR 1.26, 95%CI: 1.13-1.41, P < 0.001) and NFS > 0.676 (OR 5.03, 95%CI: 2.76-9.17, P < 0.001) were independent predictors for indication regarding statin therapy.

CONCLUSIONS

Because of increased cardiovascular risk, substantial proportions of subjects with suspected NAFLD and/or fibrosis have an indication for lipid-lowering treatment and could benefit from statin therapy.

Fatty liver and mortality: a cohort population study in South Italy

OBJECTIVE

Alcoholic fatty liver (AFLD) and non-alcoholic fatty liver (NAFLD) are two common conditions. However, if they can increase the risk of death is poorly explored. We therefore aimed to investigate the potential association between the presence and severity of liver steatosis and mortality in a large sample of older people.

DESIGN

Prospective.

SETTING

Community.

PARTICIPANTS

Women and men randomly sampled from the electoral rolls of the population of Castellana Grotte, a town in Southern Italy (Apulia region) between 2005 and 2006. Among 1942 initially contacted, 1708 (=87.9%) participated to the baseline survey (Multicentrica Colelitiasi III (MICOL III)). This specific study included 1445 older participants (mean age=65.2 years, females=44.2%).

EXPOSURE

NAFLD or AFLD.

PRIMARY AND SECONDARY OUTCOMES

Mortality (all-cause and specific-cause).

RESULTS

After a median of 12 years, 312 participants (=21.6%) died. After adjusting for nine potential confounders, the presence of steatosis was not associated with any increased risk of death in both NAFLD and AFLD. The severity of liver steatosis was not associated with any increased risk of mortality in NAFLD, while in AFLD, the presence of moderate steatosis significantly increased the risk of overall (HR=2.16; 95% CI 1.19 to 3.91) and cancer-specific (HR=3.54; 95% CI 1.16 to 10.87) death.

CONCLUSIONS

Liver steatosis is not associated with any increased risk of death in NAFLD, while moderate steatosis could be a risk factor for mortality (particularly due to cancer) in people affected by AFLD.

A Simple Index for Nonalcoholic Steatohepatitis-HUFA-Based on Routinely Performed Blood Tests

Background and objectives: Data suggests that nearly 30% of the general population have steatosis and up to 5% of this population develops nonalcoholic steatohepatitis (NASH). Liver biopsy is still considered to be the gold standard for the diagnosis of NASH. Great effort is being made toward the identification of sensitive diagnostic tests that do not involve invasive procedures to address a common concern in patients with the nonalcoholic fatty liver disease—whether they have NASH or simple steatosis. We aimed to investigate the independent predictors and develop a non-invasive, easy-to-perform, low-cost set of parameters that may be used in clinical practice to differentiate simple steatosis from NASH. Methods: А cross-sectional study of nonalcoholic fatty liver disease (NAFLD) patients divided into two groups: group I—simple steatosis (SS) and group II—biopsy-proven NASH. Strict inclusion criteria and stepwise analysis allowed the evaluation of a vast number of measured/estimated parameters. Results: One hundred and eleven patients were included—82 with simple steatosis and 29 with biopsy-proven NASH. The probability of NASH was the highest when homeostatic model assessment of insulin resistance (HOMA-IR) was above 2.5, uric acid above 380 µmol/L, ferritin above 100 µg/L and ALT above 45 U/L. An acronym of using first letters was created and named the HUFA index. This combined model resulted in an area under the receiver operator characteristic curve (AUROC) of 0.94, provided sensitivity, specificity, positive predictive value and a negative predictive value for NASH of 70.3%, 95.1%, 83.1% and 90.0%, respectively. Conclusion: We suggest a simple non-invasive predictive index HUFA that encompasses four easily available parameters (HOMA-IR, uric acid, ferritin and ALT) to identify patients with NASH, which may reduce the need for a liver biopsy on a routine basis in patients with NAFLD.

Past, present and future perspectives in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) was first described as a distinct clinical entity four decades ago. However, the condition has become the centre of attention within hepatology owing to its high prevalence and growing contribution to the burden of end-stage liver disease in the general population. This Perspective provides an overview on the development of knowledge related to NAFLD with a focus on landmark findings that have influenced current paradigms and key knowledge gaps that need to be filled to make progress. Specifically, a timeline of scientific discovery of both basic disease mechanisms (with a focus on human data) and the evolution of knowledge about the clinical course of the disease is provided and related to current approaches to treat and eventually prevent NAFLD.

Relationship between three commonly used non-invasive fibrosis biomarkers and improvement in fibrosis stage in patients with non-alcoholic steatohepatitis

BACKGROUND & AIMS

Non-invasive biomarkers are needed for monitoring changes in liver histology in patients with non-alcoholic steatohepatitis (NASH). Obeticholic acid (OCA) was shown to improve fibrosis in patients with NASH in the FLINT trial; a post hoc analysis of these data was performed to determine the relationship between 3 non-invasive fibrosis markers and liver fibrosis improvement.

METHODS

In the Phase 2b FLINT trial, patients were randomised (1:1) to receive 25 mg OCA or placebo once daily for 72 weeks. Aspartate aminotransferase:platelet ratio index (APRI), fibrosis-4 (FIB-4) index and non-alcoholic fatty liver disease fibrosis score (NFS) were evaluated in serum at baseline and weeks 24, 48, 72 and 96. Liver biopsies were obtained at baseline and 72 weeks.

RESULTS

In patients with fibrosis improvement at week 24, scores were reduced by a median of 34% for APRI, 10% for FIB-4 and 4% for NFS. Reductions in APRI (P = 0.015) and FIB-4 (P = 0.036), but not NFS (P = 0.201) at week 24, significantly correlated with ≥1-stage improvement in histologic fibrosis at week 72. Reductions in APRI at week 72 were significantly correlated with fibrosis improvement at week 72 (P = 0.012). Patients receiving OCA had significant reductions in all markers compared with patients receiving placebo at week 72 [APRI and FIB-4 (P < 0.0001); NFS (P < 0.05)].

CONCLUSIONS

Readily available non-invasive markers may predict improvement in liver fibrosis in patients with NASH. Upon external confirmation and further refinement in larger populations, these markers may serve as surrogate endpoints in NASH clinical trials.

Accuracy of Noninvasive Scoring Systems in Assessing Risk of Death and Liver-Related Endpoints in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

Several non-invasive scoring systems have been developed to determine risk of advanced fibrosis in non-alcoholic fatty liver disease (NAFLD). We examined the association between 4 scoring systems and incident severe liver disease and overall mortality in a large cohort of patients with biopsy-proven NAFLD.

METHODS

We performed a retrospective analysis of data from 646 patients with biopsy-proven NAFLD, recruited from 2 hospitals in Sweden, from 1971 through 2009. The NAFLD fibrosis score (NFS), FIB-4, APRI, and BARD scores were calculated at the time of the liver biopsy. Based on each score, patients were assigned to categories of low, intermediate, or high risk for advanced fibrosis. Overall mortality and severe liver disease (cirrhosis, decompensated liver disease, liver failure, or hepatocellular carcinoma) were ascertained through linkage with national registers until the end of 2014. Cox regression, area under the receiver operating characteristic (AUROC) curve, and C-statistic analyses were used to study the predictive capacity of each scoring system.

RESULTS

During a mean follow-up time of 19.9±8.7 years, there were 214 deaths and 76 cases of severe liver disease. For overall mortality, AUROC curve values were: NFS, 0.72 (95% CI, 0.68-0.76); FIB-4, 0.72 (95% CI, 0.68-0.76); BARD, 0.62 (95% CI, 0.58-0.66); and APRI, 0.52 (95% CI, 0.47-0.57). For severe liver disease, AUROC curve values were: NFS, 0.72 (95% CI, 0.66-0.78); FIB-4, 0.72 (95% CI, 0.66-0.79); BARD, 0.62 (95% CI, 0.55-0.69); APRI, 0.69 (95% CI, 0.63-0.76). C-statistics for all scores were of moderate capacity to predict outcomes.

CONCLUSIONS

In a retrospective analysis of data from 646 patients with biopsy-proven NAFLD, we found the NFS and the FIB-4 scores to most accurately determine risk of overall death or severe liver disease. However, the AUROC values for these scoring systems are not high enough for use in the clinic; new systems are needed to determine prognoses of patients with NAFLD.

Circadian rhythms: a possible new player in non-alcoholic fatty liver disease pathophysiology

Over the last decades, a better knowledge of the molecular machinery supervising the regulation of circadian clocks has been achieved, and numerous findings have helped in unravelling the outstanding significance of the molecular clock for the proper regulation of our physiologic and metabolic homeostasis. Non-alcoholic fatty liver disease (NAFLD) is currently considered as one of the emerging liver pathologies in the Western countries due to the modification of eating habits and lifestyle. Although NAFLD is considered a pretty benign condition, it can progress towards non-alcoholic steatohepatitis (NASH) and eventually hepatocellular carcinoma (HCC). The pathogenic mechanisms involved in NAFLD development are complex, since this disease is a multifactorial condition. Major metabolic deregulations along with a genetic background are believed to take part in this process. In this light, the aim of this review is to give a comprehensive description of how our circadian machinery is regulated and to describe to what extent our internal clock is involved in the regulation of hormonal and metabolic homeostasis, and by extension in the development and progression of NAFLD/NASH and eventually in the onset of HCC.

Evaluation of Plasma Trace Elements in Different Stages of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is considered as the hepatic manifestation of metabolic syndrome. Its global prevalence is estimated between 25 and 45%, occurring mainly in overweight individuals with unhealthy dietary habits and low levels of physical activity. Many studies have investigated the association of trace elements with liver diseases, though not with NAFLD. In this work, we investigated trace element levels in plasma of patients and not-patients and their possible association with various stages of the disease. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for the determination of As, Ba, Cd, Co, Cs, Cu, Fe, Rb, Sr, Tl, and Zn in the plasma of 189 free-living residents of Athens, Greece, either healthy or patients with mild, moderate, or severe NAFLD. The disease was diagnosed by abdominal ultrasound; blood samples were analyzed for total, HDL and LDL cholesterol, triglycerides, fasting glucose, fasting insulin, and liver enzymes, namely aspartate aminotransferase (AST), alanine transaminase (ALT), and γ-glutamyltransferase (Gamma-GT); insulin resistance was determined by the homeostatic model assessment (HOMA-IR). Zinc exhibited a statistically significant negative association with the severity of the disease, while cesium showed a statistically significant positive association. Moreover, thallium and iron were inversely associated with insulin levels. Trace element determination in plasma could be useful for establishing relationships with NAFLD status of patients. Further research is required for the verification and interpretation of these findings.

Recent research trends and updates on nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), together with metabolic syndrome and obesity, has shown a rapid increase in prevalence worldwide and is emerging as a major cause of chronic liver disease and liver transplantation. Among the various phenotypes of NAFLD, nonalcoholic steatohepatitis (NASH) is highly likely to progress to development of end-stage liver disease and cardiometabolic disease, resulting in liver-related and non-liver-related mortality. Nonetheless, there is no standardized pharmacotherapy against NASH and many drugs are under development in ongoing clinical trials. To develop a successful anti-NASH drug, it is necessary to select an appropriate target population and treatment outcomes depending on whether the mode of action is anti-metabolic, anti-inflammatory or anti-fibrotic. Recently, innovative surrogate markers have been investigated to replace hard outcomes such as liver histology and mortality and reduce the clinical trial duration. Currently, several drugs with fast track designation are being tested in phase III clinical trials, and many other drugs have moved into phase II clinical trials. Both lean NAFLD and typical obese NAFLD have been extensively studied and genetic variants such as PNPLA3 and TM6SF2 have been identified as significant risk factors for lean NAFLD. In the near future, noninvasive biomarkers and effective targeted therapies for NASH and associated fibrosis are required to develop precision medicine and tailored therapy according to various phenotypes of NAFLD.

Prediction of fatty liver disease using machine learning algorithms

BACKGROUND AND OBJECTIVE

Fatty liver disease (FLD) is a common clinical complication; it is associated with high morbidity and mortality. However, an early prediction of FLD patients provides an opportunity to make an appropriate strategy for prevention, early diagnosis and treatment. We aimed to develop a machine learning model to predict FLD that could assist physicians in classifying high-risk patients and make a novel diagnosis, prevent and manage FLD.

METHODS

We included all patients who had an initial fatty liver screening at the New Taipei City Hospital between 1st and 31st December 2009. Classification models such as random forest (RF), Naïve Bayes (NB), artificial neural networks (ANN), and logistic regression (LR) were developed to predict FLD. The area under the receiver operating characteristic curve (ROC) was used to evaluate performances among the four models.

RESULTS

A total of 577 patients were included in this study; of those 377 patients had fatty liver. The area under the receiver operating characteristic (AUROC) of RF, NB, ANN, and LR with 10 fold-cross validation was 0.925, 0.888, 0.895, and 0.854 respectively. Additionally, The accuracy of RF, NB, ANN, and LR 87.48, 82.65, 81.85, and 76.96%.

CONCLUSION

In this study, we developed and compared the four classification models to predict fatty liver disease accurately. However, the random forest model showed higher performance than other classification models. Implementation of a random forest model in the clinical setting could help physicians to stratify fatty liver patients for primary prevention, surveillance, early treatment, and management.

Insights into the Epidemiology, Pathogenesis, and Therapeutics of Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease which affects ≈25% of the adult population worldwide, placing a tremendous burden on human health. The disease spectrum ranges from simple steatosis to steatohepatitis, fibrosis, and ultimately, cirrhosis and carcinoma, which are becoming leading reasons for liver transplantation. NAFLD is a complex multifactorial disease involving myriad genetic, metabolic, and environmental factors; it is closely associated with insulin resistance, metabolic syndrome, obesity, diabetes, and many other diseases. Over the past few decades, countless studies focusing on the investigation of noninvasive diagnosis, pathogenesis, and therapeutics have revealed different aspects of the mechanism and progression of NAFLD. However, effective pharmaceuticals are still in development. Here, the current epidemiology, diagnosis, animal models, pathogenesis, and treatment strategies for NAFLD are comprehensively reviewed, emphasizing the outstanding breakthroughs in the above fields and promising medications in and beyond phase II.

Association of TM6SF2 rs58542926 gene polymorphism with the risk of non-alcoholic fatty liver disease and colorectal adenoma in Chinese Han population

Background

Genetic factors affect the risk of non-alcoholic fatty liver disease (NAFLD) and colorectal adenoma (CRA) importantly. Transmembrane protein 6 superfamily member 2 (TM6SF2) rs58542926 is a significant genetic susceptibility site for NAFLD. The relationships of TM6SF2 rs58542926 with the risk of NAFLD and CRA in Chinese Han population were unclear. The aim of this study was to investigate the association of TM6SF2 rs58542926 with the risk of NAFLD and CRA, and the effect of CRA on TM6SF2 rs58542926 carried NAFLD patients.

Results

A total of 839 Chinese Han population were included in this retrospective study. TM6SF2 rs58542926 polymorphism was genotyped in B-type ultrasonography proven NAFLD patients with or without CRA, CRA patients and healthy controls, using polymerase chain reaction. Serum lipid profiles were determined using biochemical methods. Statistical analyses were performed using SPSS statistical software, version 16.0 for mac. There was a significant difference in the distribution of genotype and allele of TM6SF2 rs58542926 in NAFLD and NAFLD&CRA patients compared to controls. The CT + TT genotypes were tightly associated with the risk of NAFLD and NAFLD&CRA. TM6SF2 rs58542926 T allele promotes the abnormal regulation of lipids metabolism and liver injury in NAFLD patients and NAFLD&CRA patients. CRA aggravates the clinical performance of NAFLD in T allele carriers.

Conclusions

We demonstrated the significant association between TM6SF2 rs58542926 polymorphism and the risk of NAFLD and NAFLD&CRA in a Chinese Han population. The TM6SF2 rs58542926 T allele promotes the abnormal regulation of lipid profiles and liver injury in NAFLD patients, NAFLD&CRA patients, and overall subjects.

Non-invasive diagnosis and biomarkers in alcohol-related liver disease

Even though alcohol-related liver disease (ALD) is a major cause of severe liver disease worldwide, most patients with ALD are diagnosed at the decompensation stage. Liver biopsy is still considered the gold standard for establishing a definite diagnosis and assessing the fibrosis stage of ALD, but it is an invasive procedure, associated with significant morbidity. During the last decade, non-invasive tests have been developed to estimate the severity of liver fibrosis and steatosis. Measurement of liver stiffness by transient elastography has become the most commonly used non-invasive parameter to evaluate fibrosis. In ALD, transient elastography has been demonstrated to have an excellent performance to detect advanced fibrosis and cirrhosis. However, aspartate aminotransferase levels must be considered when interpreting liver stiffness cut-offs. Non-invasive biological tests have also been evaluated to assess liver fibrosis in ALD. The commercially available Enhanced Liver Fibrosis test and FibroTest have comparable performance for the diagnosis of advanced fibrosis in ALD, with studies suggesting that they are better than other biological tests (i.e. FIB-4 and APRI). Although ultrasound is still accepted as an initial screen for fatty liver diagnosis, new methods have recently been developed to detect steatosis. Magnetic resonance spectroscopy and magnetic resonance imaging techniques are highly accurate and reproducible, with superior sensitivities and specificities for detecting histological steatosis than ultrasound. However, low availability and high cost limit the use of magnetic resonance techniques in routine clinical practice. More recently, controlled attenuation parameter was developed as a novel tool to non-invasively assess liver steatosis; performed in combination with transient elastography, it was suggested to be superior to regular ultrasound for detecting steatosis and was shown to have acceptable diagnostic accuracy. New serum biomarkers are under investigation to non-invasively diagnose more severe forms of ALD and to predict prognosis of patients.

Nonalcoholic Fatty Liver Disease in Diabetes. Part I: Epidemiology and Diagnosis

Nonalcoholic fatty liver disease (NAFLD) and diabetes are common metabolic disorders whose prevalence rates are expected to rise worldwide, corresponding to aging and increasingly obese populations. Compared to the general population (around 25%), 50% to 70% of people with diabetes have NAFLD, and NAFLD severity (including fibrosis) tends to be worsened by the presence of diabetes. NAFLD is considered an emerging risk factor for type 2 diabetes mellitus and a contributor to the development of chronic diabetes-related complications. This reciprocal relationship demonstrates the importance of confirming suspected NAFLD in patients with diabetes. Due to the invasive nature of liver biopsy to assess NAFLD status, various alternative non-invasive modalities have been developed and validated. Here, we summarized the epidemiology of NAFLD in patients with diabetes and reviewed currently available imaging modalities and biomarker-based prediction models for their ability to detect liver steatosis and/or fibrosis.

The Mexican consensus on nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) affects nearly one third of the population worldwide. Mexico is one of the countries whose population has several risk factors for the disease and its prevalence could surpass 50%. If immediate action is not taken to counteract what is now considered a national health problem, the medium-term panorama will be very bleak. This serious situation prompted the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Hepatología to produce the Mexican Consensus on Fatty Liver Disease. It is an up-to-date and detailed review of the epidemiology, pathophysiology, clinical forms, diagnosis, and treatment of the disease, whose aim is to provide the Mexican physician with a useful tool for the prevention and management of nonalcoholic fatty liver disease.

Transient Elastography and Controlled Attenuation Parameter (CAP) in the Assessment of Liver Steatosis in Severe Adult Growth Hormone Deficiency

Non-alcoholic fatty liver disease (NAFLD) is common in patients with growth hormone deficiency (GHD). Some noninvasive techniques have been used to quantify liver fat, such as the controlled attenuation parameter (CAP). Objective: To evaluate CAP as a tool to identify liver steatosis and its relationship with different clinical and biochemical metabolic parameters in a group of patients with severe adult growth hormone deficiency (AGHD), and to compare the evolution of metabolic profiles after 6 months of human growth hormone (rhGH) replacement therapy in a subgroup of patients. Methods: Cross-sectional observational study at baseline of naive rhGH multiple pituitary hormonal deficiency (MPHD) hypopituitarism patients. A 6-month intervention clinical trial in a selected group of a non-randomized, non-controlled cohort was also applied. Results: Liver stiffness measurement (LSM) was normal in severe AGHD patients. CAP evaluation showed steatosis in 36.3% of baseline patients (8/22), associated with higher BMI, waist circumference, insulin, and alanine aminotransferase (ALT) levels. According to steatosis degree by CAP, child-onset growth hormone deficiency (CO-GHD) was graded as 68.75% (11/16) S0, 12.5% (2/16) S1, and 18.75% (3/16) S3, whereas AO-GHD was graded as 50% (3/6) S0, 16.66% (1/6) S2, and 33.33% S3. After 6 months of hrGH replacement, CAP measurements did not change significantly, neither on group without hepatic steatosis at baseline (194.4 ± 24.3 vs. 215.4 ± 51.3; p = 0.267) nor on the group with hepatic steatosis (297.2 ± 32.3 vs. 276.4 ± 27.8; p = 0.082). A significant improvement of body composition was observed only in the first group. Conclusions: We have demonstrated the importance of CAP as a non-invasive tool in the liver steatosis identification on hypopituitary patients. This method may be an important indicator of the severity of metabolic disorders in MPHD patients. In our study, no liver health modification in LSM at baseline or after 6 months of rhGH replacement was found. Longer studies can help to establish the potential repercussions of growth hormone replacement therapy on liver steatosis.

Range of Normal Liver Stiffness and Factors Associated With Increased Stiffness Measurements in Apparently Healthy Individuals

BACKGROUND & AIMS

Transient elastography (TE) is a noninvasive technique used to measure liver stiffness to estimate the severity of fibrosis. The range of liver stiffness measurements (LSMs) in healthy individuals is unclear. We performed a systematic review to determine the range of LSMs, examined by TE, in healthy individuals and individuals who are susceptible to fibrosis.

METHODS

We collected data from 16,082 individuals, in 26 cohorts, identified from systematic searches of Embase, Ovid MEDLINE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for studies of liver stiffness measurements. Studies analyzed included apparently healthy adults (normal levels of liver enzymes, low-risk alcohol use patterns, and negative for markers of viral hepatitis). The presence of diabetes, hypertension, dyslipidemia, or steatosis, based on ultrasound examination, was known for most participants. We performed a meta-analysis of data from individual participants. The cohort was divided into 4 groups; participants with a body mass index <30 kg/m² were examined with the medium probe and those with a body mass index ≥30 kg/m² were examined with the extra-large probe. Linear regression models were conducted after adjusting for potential confounding factors of LSMs. We performed several sensitivity analyses.

RESULTS

We established LSM ranges for healthy individuals measured with both probes-these did not change significantly in sensitivity analyses of individuals with platelets ≥150,000/mm³ and levels of alanine aminotransferase ≤33 IU/L in men or ≤25 IU/L in women. In multivariate analysis, factors that modified LSMs with statistical significance included diabetes, dyslipidemia, waist circumference, level of aspartate aminotransferase, and systolic blood pressure at examination time. Significant increases in LSMs were associated with the metabolic syndrome in individuals examined by either probe. Diabetes in obese individuals increased the risk of LSMs in the range associated with advanced fibrosis.

CONCLUSIONS

In a systematic review and meta-analysis of data from individual participants, we established a comprehensive set of LSM ranges, measured by TE in large cohorts of healthy individuals and persons susceptible to hepatic fibrosis. Regression analyses identified factors associated with increased LSMs obtained by TE with the medium and extra-large probes.

The Comparison of Simple Anthropometric and Biochemical Parameters for Predicting Liver Steatosis in Obese Balinese Young Women

BACKGROUND:

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing globally. Early identification of liver steatosis (LS) status is critical to prevent the development of NAFLD into non-alcoholic steatohepatitis (NASH) fibrosis.

AIM:

This study aimed at exploring the validity of simple anthropometric and biochemical parameters to predict LS in young obese women.

MATERIALS AND METHODS:

This is a cross-sectional study involving 132 young obese women. We collected the data of measured waist circumference (WC), body mass index (BMI), serum triglyceride (TG), and gamma-glutamyltransferase (GGT). The lipid accumulation product (LAP) was designed from TG and WC variables. Fatty liver index (FLI) was calculated from TG, BMI, WC, and GGT variables. LS status was measured using ultrasonography assay. Statistical significance was set at p < 0.05.

RESULTS:

A positive correlation was found between BMI, WC, TG, GGT, LAP, FLI, and LS (p = 0.001). We found that BMI is a better predictor for LS to WC. Our multiple linear regression analysis revealed that BMI, GGT, and TG could predict 41.4% of LS. The validity (specificity, sensitivity, and odds ratio) of simple body fat parameters in predicting LS were as follows: BMI ≥ 30 kg/m² (69.6%, 74.4%, and 6.21), WC ≥ 90 cm (67.4%, 70.0%, and 4.28), TG ≥ 100 mg/dL (70.6%, 70.0%, and 5.62) and GGT ≥ 20 μg/L (69.6%, 77.5%, and 7.87), as well as LAP ≥ 30 (82.6%, 70.0%, and 11.1), and FLI ≥ 2.5 (79.3%, 72.5%, and 10.1), significantly.

CONCLUSION:

Simple anthropometric and biochemical parameters (BMI, WC, and TG, GGT), are appropriately predicting LS as well as LAP, and FLI among obese Balinese young women.

Prevalence and severity of nonalcoholic fatty liver disease by transient elastography: Genetic and metabolic risk factors in a general population

BACKGROUND & AIMS

The worldwide spread of obesity is leading to a dramatic increase in the prevalence of nonalcoholic fatty liver disease (NAFLD) and its complications. We aimed to evaluate both prevalence and factors associated with NAFLD in a general population in a Mediterranean area.

METHODS

We considered 890 consecutive individuals included in the community-based ABCD (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340). Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were measured with FibroScan. Participants were genotyped for PNPLA3 rs738409 and TM6SF2 rs58542926 variants.

RESULTS

The prevalence of NAFLD in the cohort was 48%. NAFLD participants exhibited elevated LSM values, suggesting advanced fibrosis (6.5% of cases). Both NAFLD and advanced fibrosis were independently associated with traditional risk factors (NAFLD: age >50 years, obesity, hypertension, elevated ALT and low HDL-cholesterol serum concentrations. Advanced fibrosis: IFG/diabetes, elevated ALT serum concentrations). A high prevalence (>60%) of NAFLD was found in obese people, while it varied widely in non-obese people according to the presence of metabolic risk factors. PNPLA3 G variant (OR = 1.33, 95% C.I. = 1.01-1.8; P < .05) was independently associated with NAFLD. Prevalence of advanced fibrosis (high LSM values) ranged from 3.4% (no risk factors) to 60% (presence of all risk factors). TM6SF2 T variant (OR = 3.06, 95% C.I. = 1.08-8.65, P < .05) was independently associated with advanced fibrosis (high LSM values).

CONCLUSIONS

In a cohort of a general population, the prevalence of NAFLD was very high, and among NAFLD patients a significant proportion had advanced fibrosis (high LSM values). Apart from traditional risk factors, genetic factors may have a significant role that needs to be further investigated.

Magnetic resonance elastography of liver and spleen: Methods and applications

The viscoelastic properties of the liver and spleen can be assessed with magnetic resonance elastography (MRE). Several actuators, MRI acquisition sequences and reconstruction algorithms have been proposed for this purpose. Reproducible results are obtained, especially when the examination is performed in standard conditions with the patient fasting. Accurate staging of liver fibrosis can be obtained by measuring liver stiffness or elasticity with MRE. Moreover, emerging evidence shows that assessing the tissue viscous parameters with MRE is useful for characterizing liver inflammation, non-alcoholic steatohepatitis, hepatic congestion, portal hypertension, and hepatic tumors. Further advances such as multifrequency acquisitions and compression-sensitive MRE may provide novel quantitative markers of hepatic and splenic mechanical properties that may improve the diagnosis of hepatic and splenic diseases.

Prevalence of hepatic steatosis as assessed by controlled attenuation parameter (CAP) in subjects with metabolic risk factors in primary care. A population-based study

Background

Primary care is the ideal setting for early identification of patients with non-alcoholic fatty liver disease (NAFLD). NAFLD is a potentially progressive disease that may lead to cirrhosis and liver cancer but is frequently underrecognized because subjects at risk are often not evaluated. Controlled attenuation parameter (CAP) is a reliable method for non-invasive quantification of liver fat. It has the advantage of simultaneous measurement of liver stiffness (LS), an estimate of liver fibrosis. There is no information on CAP in subjects with risk factors from primary care.

Aim

To investigate the prevalence of hepatic steatosis, as estimated by CAP, in subjects from the community with metabolic risk factors and correlate findings with clinical and biochemical characteristics and LS.

Patients and methods

Population-based study of 215 subjects with metabolic risk factors without known liver disease identified randomly from a primary care center. A control group of 80 subjects matched by age and sex without metabolic risk factors was also studied. CAP and LS were assessed using Fibroscan.

Results

Subjects with risk factors had CAP values higher than those of control group (268±64 vs 243±49dB/m,p<0.001). Prevalence of severe steatosis (CAP> 280dB/m) in subjects with risk factors was 43%. In multivariate analysis, fatty liver index (FLI) and HOMA were independent predictive factors of severe steatosis. There was a direct correlation between CAP and FLI values (r = 0.52,p<0.001). Interestingly, prevalence of increased LS was 12.6% in the risk group vs 0% in the control group (p<0.001). Increased LS occurred predominantly in subjects with high CAP values.

Conclusions

A high proportion of subjects with metabolic risk factors seen in primary care have severe steatosis. FLI could be used as a surrogate of CAP. Increased LS was found in a significant proportion of subjects with risk factors but not in control subjects.

Anthropometric and blood parameters for the prediction of NAFLD among overweight and obese adults

Backround

Non-alcoholic fatty liver disease (NAFLD) comprises non-progressive steatosis and non-alcoholic steatohepatitis (NASH), the latter of which may cause cirrhosis and hepatocellular carcinoma (HCC). As NAFLD detection is imperative for the prevention of its complications, we evaluated whether a combination of blood-based biomarkers and anthropometric parameters can be used to predict NAFLD among overweight and obese adults.

Methods

143 overweight or obese non-smokers free of diabetes (50% women, age: 35–65 years) were recruited. Anthropometric indices and routine biomarkers of metabolism and liver function were measured to predict magnetic resonance (MR) - derived NAFLD by multivariable logistic regression models. In addition, we evaluated to which degree the use of more novel biomarkers (adiponectin, leptin, resistin, C-reactive protein, TNF-α, IL-6, IL-8 and interferon-γ) could improve prediction models.

Results

NAFLD was best predicted by a combination of age, sex, waist circumference, ALT, HbA1c, and HOMA-IR at an area under the receiver operating characteristic curve (AUROC) of 0.87 (95% CI: 0.81, 0.93) before and 0.85 (95% CI: 0.78, 0.91) after internal bootstrap validation. The use of additional biomarkers of inflammation and metabolism did not improve NAFLD prediction. Previously published indices predicted NAFLD at AUROCs between 0.71 and 0.82.

Conclusions

The AUROC of > 0.8 obtained by our regression model suggests the feasibility of a non-invasive detection of NAFLD by anthropometry and circulating biomarkers, even though further increments in the capacity of prediction models may be needed before NAFLD indices can be applied in routine clinical practice.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0840-9) contains supplementary material, which is available to authorized users.

Diagnostic modalities for nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, and associated fibrosis

Nonalcoholic fatty liver disease (NAFLD) is a spectrum comprised of isolated steatosis, nonalcoholic steatohepatitis (NASH), advanced fibrosis, and cirrhosis. The majority of NAFLD subjects do not have NASH and do not carry a significant risk for liver-related adverse outcomes (cirrhosis and mortality). Globally, the prevalence of NAFLD is approximately 25%. In Asia, a gradient of high to low prevalence rates is noted from urban to rural areas. Given the prevalence of NAFLD, the clinical and economic burden of NAFLD and NASH can be substantial. With increasing recognition of NASH as an important liver disease, the diagnosis of NASH still requires a liver biopsy that is suboptimal. Although liver biopsy is the most accurate modality to diagnose and stage the severity of NASH, this method suffers from being invasive, costly, associated with potential complications, and plagued with interobserver variability of individual pathological features. A number of noninvasive modalities to diagnose NASH and stage liver fibrosis are being developed. These modalities include predictive models (NAFLD fibrosis score) and serum biomarkers such as enhanced liver fibrosis (ELF). Other tests are based on radiological techniques, such as transient elastography (TE) or magnetic resonance elastography (MRE), which are used to estimate liver stiffness as a potential surrogate of hepatic fibrosis. Although a dynamic field of research, most of these diagnostic modalities have area under the curve ranging between 0.76 and 0.90%, with MRE having the best predictive performance. In summary, developing safe and easily accessible noninvasive modalities to accurately diagnose and monitor NASH and associated fibrosis is of utmost importance in clinical practice and clinical research. These tests are not only important to risk stratify subjects at the greatest risk for progressive liver disease, but also to serve as appropriate surrogate endpoints for therapeutic clinical trials of NASH. (Hepatology 2018;68:349-360).

Diagnostic modalities for nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, and associated fibrosis

Nonalcoholic fatty liver disease (NAFLD) is a spectrum comprised of isolated steatosis, nonalcoholic steatohepatitis (NASH), advanced fibrosis, and cirrhosis. The majority of NAFLD subjects do not have NASH and do not carry a significant risk for liver-related adverse outcomes (cirrhosis and mortality). Globally, the prevalence of NAFLD is approximately 25%. In Asia, a gradient of high to low prevalence rates is noted from urban to rural areas. Given the prevalence of NAFLD, the clinical and economic burden of NAFLD and NASH can be substantial. With increasing recognition of NASH as an important liver disease, the diagnosis of NASH still requires a liver biopsy that is suboptimal. Although liver biopsy is the most accurate modality to diagnose and stage the severity of NASH, this method suffers from being invasive, costly, associated with potential complications, and plagued with interobserver variability of individual pathological features. A number of noninvasive modalities to diagnose NASH and stage liver fibrosis are being developed. These modalities include predictive models (NAFLD fibrosis score) and serum biomarkers such as enhanced liver fibrosis (ELF). Other tests are based on radiological techniques, such as transient elastography (TE) or magnetic resonance elastography (MRE), which are used to estimate liver stiffness as a potential surrogate of hepatic fibrosis. Although a dynamic field of research, most of these diagnostic modalities have area under the curve ranging between 0.76 and 0.90%, with MRE having the best predictive performance. In summary, developing safe and easily accessible noninvasive modalities to accurately diagnose and monitor NASH and associated fibrosis is of utmost importance in clinical practice and clinical research. These tests are not only important to risk stratify subjects at the greatest risk for progressive liver disease, but also to serve as appropriate surrogate endpoints for therapeutic clinical trials of NASH. (Hepatology 2018;68:349-360).

The Effects of Physical Exercise on Fatty Liver Disease

The increasing prevalence of obesity has made nonalcoholic fatty liver disease (NAFLD) the most common chronic liver disease. As a consequence, NAFLD and especially its inflammatory form nonalcoholic steatohepatitis (NASH) are the fastest increasing etiology of end-stage liver disease and hepatocellular carcinoma. Physical inactivity is related to the severity of fatty liver disease irrespective of body weight, supporting the hypothesis that increasing physical activity through exercise can improve fatty liver disease. This review summarizes the evidence for the effects of physical exercise on NAFLD and NASH. Several clinical trials have shown that both aerobic and resistance exercise reduce the hepatic fat content. From clinical and basic scientific studies, it is evident that exercise affects fatty liver disease through various pathways. Improved peripheral insulin resistance reduces the excess delivery of free fatty acids and glucose for free fatty acid synthesis to the liver. In the liver, exercise increases fatty acid oxidation, decreases fatty acid synthesis, and prevents mitochondrial and hepatocellular damage through a reduction of the release of damage-associated molecular patterns. In conclusion, physical exercise is a proven therapeutic strategy to improve fatty liver disease.

Diagnostic performance of a new noninvasive test for nonalcoholic steatohepatitis using a simplified histological reference

BACKGROUND

One of the unmet needs in patients with metabolic risks is the prediction of metabolic liver disease (MLD) by noninvasive tests (NITs).

OBJECTIVE

The primary aim of this study was to construct a new quantitative test for the diagnosis of nonalcoholic steatohepatitis (NASH) using a simplified histological definition.

PATIENTS AND METHODS

As a reference, we used a simplified histological definition of NASH derived from the FLIP-CRN-definition that does not require the presence of steatosis and the presence of both lobular inflammation and ballooning. We analyzed 1081 patients from two prospective cohorts at risk of MLD who had biopsies and contemporaneous blood samples. These patients were divided randomly into a training group (n=541) and a control group (n=540) for internal validation. The new test was compared with standard tests, and applied in two large populations at risk of MLD.

RESULTS

Out of 1081 patients with biopsy, 39 (3.6%) cases with significant inflammatory activity or fibrosis (A2orF2) were missed by the current histological definitions. The combination of 11 parameters permitted to construct a test (NIT-NASHs) predicting NASH with an area under the receiver operating characteristic curve (AUROC) of 0.773 (95% confidence interval: 0.730-0.810), confirmed in the control group 0.814 (0.774-0.847). The AUROCs of NIT-NASHs were higher (all P<0.001) than those of ActiTest, FIB4, BARD, and nonalcoholic fatty liver disease scores. A combination of NIT-NASHs with FibroTest (AUROC=0.800; 0.759-0.835) enabled a better prediction (P<0.0001) of significant MLD, A2orF2, than the ActiTest-FibroTest combination.

CONCLUSION

These results suggested that this new test enables a quantitative assessment of NASH, and when associated with the FibroTest, identifies cases with clinically significant MLD. An external validation is needed.

Impact of steatosis and inflammation definitions on the performance of NASH tests

BACKGROUND AND AIM

One of the unmet needs in subjects with metabolic risks is the prediction of metabolic liver disease by noninvasive tests. The construction of performant tests is dependent on the appropriateness of the histological reference definition. The aim of this study was to analyze the limitations of similar European (Fatty Liver Inhibition of Progression) and USA (Clinical-Research-Network) standard definitions and their impact on the construction of tests.

METHODS

We hypothesized that a simpler histological definition of non-alcoholo steato-hepatitis (NASH), which does not require the presence of steatosis and the presence of both lobular inflammation and ballooning, should improve the concordance rates with previously validated blood tests. We reviewed the landmark studies in metabolic liver disease, sources of the standard definitions, and we compared the adequacy of these standards to other possible definitions in 1081 subjects with biopsies, by concordance and accuracy rates.

RESULTS

The limitations of standard definitions included the presence of appropriate controls in only 6.6% of landmark studies, an arbitrary definition of steatosis and NASH covering only four (15%) out of 27 possible combinations of features, compared with 18 (67%) for a simplified NASH definition, which did not require steatosis. A total of 39/1081 (3.6%) cases were not identified by standard definition, but were identified by the simplified definition as significant active disease, including 15 cases with significant fibrosis. The simplified definition increased the κ concordance (P<0.0001) between test prediction and histological reference.

CONCLUSION

A simplified definition of NASH could help in the construction of biomarkers with higher performances.

Needle-shaped ultrathin piezoelectric microsystem for guided tissue targeting via mechanical sensing

Needles for percutaneous biopsies of tumour tissue can be guided by ultrasound or computed tomography. However, despite best imaging practices and operator experience, high rates of inadequate tissue sampling, especially for small lesions, are common. Here, we introduce a needle-shaped ultrathin piezoelectric microsystem that can be injected or mounted directly onto conventional biopsy needles and used to distinguish abnormal tissue during the capture of biopsy samples, through quantitative real-time measurements of variations in tissue modulus. Using well-characterized synthetic soft materials, explanted tissues and animal models, we establish experimentally and theoretically the fundamental operating principles of the microsystem, as well as key considerations in materials choices and device designs. Through systematic tests on human livers with cancerous lesions, we demonstrate that the piezoelectric microsystem provides quantitative agreement with magnetic resonance elastography, the clinical gold standard for the measurement of tissue modulus. The piezoelectric microsystem provides a foundation for the design of tools for the rapid, modulus-based characterization of tissues.

Role of imaging-based biomarkers in NAFLD: Recent advances in clinical application and future research directions

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem afflicting approximately one billion individuals worldwide. Liver biopsy is considered the gold standard for assessment of liver disease severity in patients with NAFLD. However, it is invasive, has high inter-observer variability, and is associated with adverse effects, including pain, infection and, albeit rarely, death. It is also impractical because of the large number of individuals who have NAFLD. Therefore, tools to non-invasively assess disease severity in NAFLD are urgently needed. Over the last two decades, tremendous advances have been made in the assessment of NAFLD by non-invasive imaging. In this review, we will discuss the different non-invasive imaging modalities available to quantify liver fat and liver fibrosis. We will also discuss the limitations of current modalities to detect the progressive form for NAFLD, termed non-alcoholic steatohepatitis. Finally, we will discuss the comparative efficacy of various imaging-based elastographic modalities for detection of advanced fibrosis or cirrhosis, as well as their diagnostic characteristics.