Which clinical and sonographic parameters may be useful to discriminate NASH from steatosis?

Accuracy of Non-Invasive Imaging Techniques for the Diagnosis of MASH in Patients With MASLD: A Systematic Review

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing public health problem. The secondary stage in MASLD is steatohepatitis (MASH), the co-existence of steatosis and inflammation, a leading cause of progression to fibrosis and mortality. MASH resolution alone improves survival. Currently, MASH diagnosis is via liver biopsy. This study sought to evaluate the accuracy of imaging-based tests for MASH diagnosis, which offer a non-invasive method of diagnosis.

METHODS

Eight academic literature databases were searched and references of previous systematic reviews and included papers were checked for additional papers. Liver biopsy was used for reference standard.

RESULTS

We report on 69 imaging-based studies. There were 31 studies on MRI, 27 on ultrasound, five on CT, 13 on transient elastography, eight on controlled attenuation parameter (CAP) and two on scintigraphy. The pathological definition of MASH was inconsistent, making it difficult to compare studies. 55/69 studies (79.71%) were deemed high-risk of bias as they had no preset thresholds and no validation. The two largest groups of imaging papers were on MRI and ultrasound. AUROCs were up to 0.93 for MRE, 0.90 for MRI, 1.0 for magnetic resonance spectroscopy (MRS) and 0.94 for ultrasound-based studies.

CONCLUSIONS

Our study found that the most promising imaging tools are MRI techniques or ultrasound-based scores and confirmed there is potential to utilise these for MASH diagnosis. However, many publications are single studies without independent prospective validation. Without this, there is no clear imaging tool or score currently available that is reliably tested to diagnose MASH.

Crosstalk Between the Spleen and Other Organs/Systems: Downstream Signaling Events

The aim of this review was to gather pieces of information from available critically evaluated published articles concerning any interplay in which the spleen could be involved. For many years, the spleen has been alleged as an unnecessary biological structure, even though splenomegaly is an objective finding of many illnesses. Indeed, the previous opinion has been completely changed. In fact, the spleen is not a passive participant in or a simple bystander to a relationship that exists between the immune system and other organs. Recently, it has been evidenced in many preclinical and clinical studies that there are close associations between the spleen and other parts of the body, leading to various spleen–organ axes. Among them, the gut–spleen axis, the liver–spleen axis, the gut–spleen–skin axis, the brain–spleen axis, and the cardio-splenic axis are the most explored and present in the medical literature. Such recent sources of evidence have led to revolutionary new ideas being developed about the spleen. What is more, these observations may enable the identification of novel therapeutic strategies targeted at various current diseases. The time has come to make clear that the spleen is not a superfluous body part, while health system operators and physicians should pay more attention to this organ. Indeed, much work remains to be performed to assess further roles that this biological structure could play.

Conventional ultrasound for diagnosis of hepatic steatosis is better than believed

BACKGROUND

Hepatic steatosis is a condition frequently encountered in clinical practice, with potential progression towards fibrosis, cirrhosis, and hepatocellular carcinoma. Detection and staging of hepatic steatosis are of most importance in nonalcoholic fatty liver disease (NAFLD), a disease with a high prevalence of more than 1 billion individuals affected. Ultrasound (US) is one of the most used noninvasive imaging techniques used in the diagnosis of hepatic steatosis. Detection of hepatic steatosis with US relies on several conventional US parameters, which will be described. US is the first-choice imaging in adults at risk for hepatic steatosis. The use of some scoring systems may add additional accuracy especially in assessing the severity of hepatic steatosis.

SUMMARY

In the presented paper, we discuss screening and risk stratification, ultrasound features for diagnosing hepatic steatosis, B-mode criteria, focal fatty patterns and Doppler features of the hepatic vessels, and the value of the different US signs for the diagnosis of liver steatosis including classifying the severity of steatosis using different US scores. Limitations of conventional B-mode and Doppler features in the evaluation of hepatic steatosis are also discussed, including those in grading and assessing the complications of steatosis, namely fibrosis and nonalcoholic steatohepatitis.

KEY MESSAGES

Ultrasound is the first-line imaging examination for the screening and follow-up of patients with liver steatosis. The use of some scoring systems may add additional accuracy in assessing the severity of steatosis. Conventional B-mode and Doppler ultrasound have limitations in grading and assessing the complications of steatosis.

Liver-spleen axis in nonalcoholic fatty liver disease

Introduction: NAFLD is often under-diagnosed, even though rates of its co-morbidities such as obesity and type2 diabetes mellitus, prominent statuses of inflammation, are significantly high. The spleen-liver axis is gaining much credit in the last years like other well-known organ axes.Areas covered: PubMed/MEDLINE was searched for relevant articles related to concomitant occurrence of NAFLD and spleen. Areas covered in this review include: (1) updated findings of spleen dimensions at ultrasonography, (2) discussion of current data on pathophysiological connections between obesity-related NAFLD and increased volume of the spleen, and (3) analysis of current immune-mediated mechanisms characterizing the so.called chronic low-grade inflammation leading to insulin resistance.Expert opinion: The advances in explaining mechanisms underlying the spleen involvement in immune regulation, coupled with research about the role of spleen in NAFLD, could impact real world outcomes through establishing better tools for a precocious diagnosis. Using both liver and spleen ultrasonography, technique largely dealt with in this review, could expand the possibility to cover an adequate diagnostic path toward NAFLD, reaching a good sensibility and specificity.

The clinical utility of accurate NAFLD ultrasound grading: Results from a community-based, prospective cohort study

OBJECTIVES

Despite its widespread use there is no consensus on ultrasound criteria to diagnose fatty liver.

METHOD

In an ongoing, cohort-study, participants were initially screened in 2007 and reassessed in 2014 by interview, anthropometric measurements, liver ultrasonography, and blood tests. We evaluated utility of increased hepatic echogenicity alone (intermediate) compared to using additional criteria which included signal attenuation and/or vascular blunting along with increase of hepatic echogenicity (moderate-severe), to diagnose fatty liver in NAFLD. We made a comparison of the two radiologically defined groups, in order to choose a classification method for NAFLD, which may better predict baseline adverse metabolic traits (MT), and adverse metabolic and cardiovascular events (CVE) after 7-year of follow-up.

RESULTS

Of 2985 recruited in 2007, 940 (31.5 %) had moderate-severe NAFLD, 595 (19.9 %) intermediate NAFLD, and 957 (32.1 %) were controls (no fatty liver). 2148 (71.9 %) attended follow-up in 2014; they included 708 who had moderate-severe NAFLD, 446 intermediate NAFLD and 674 controls, at baseline (in 2007). At baseline, adverse anthropometric indices and MTs were significantly higher in both moderate-severe NAFLD and intermediate NAFLD compared to controls, except for low HDL. They were commoner in moderate-severe NAFLD than in intermediate NAFLD. After seven years, the odds of developing new-onset metabolic traits and CVEs were significantly higher compared to controls only in moderate-severe NAFLD.

CONCLUSIONS

Only moderate-severe NAFLD predicted risk of incident adverse MTs and CVEs. However, both moderate-severe and intermediate NAFLD were associated with higher prevalence of adverse anthropometric and metabolic traits, thereby identifying individuals who need medical intervention even among those with milder degrees of fatty liver. We therefore recommend using increased hepatic echogenicity, and not only the more stringent criteria (which include signal attenuation and/or vascular blunting), for the diagnosis of fatty liver in individuals with NAFLD.

Non-Alcoholic Steatohepatitis Decreases Microsomal Liver Function in the Absence of Fibrosis

The incidence of non-alcoholic fatty liver disease (NAFLD) is rising across the globe, with the presence of steatohepatitis leading to a more aggressive clinical course. Currently, the diagnosis of non-alcoholic steatohepatitis (NASH) is based on histology, though with the high prevalence of NAFLD, a non-invasive method is needed. The 13C-aminopyrine breath test (ABT) evaluates the microsomal liver function and could be a potential candidate. We aimed to evaluate a potential change in liver function in NASH patients and to evaluate the diagnostic power of ABT to detect NASH. We performed a retrospective analysis on patients suspected of NAFLD who underwent a liver biopsy and ABT. 440 patients were included. ABT did not decrease in patients with isolated liver steatosis but decreased significantly in the presence of NASH without fibrosis and decreased even further with the presence of significant fibrosis. The predictive power of ABT as a single test for NASH was low but improved in combination with ALT and ultrasonographic steatosis. We conclude that microsomal liver function of patients with NASH is significantly decreased, even in the absence of fibrosis. The ABT is thus a valuable tool in assessing the presence of NASH; and could be used as a supplementary diagnostic tool in clinical practice.

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

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

Semi-Quantitative Ultrasonographic Evaluation of NAFLD

Nonalcoholic fatty liver disease (NAFLD) embraces histopathological entities ranging from the relatively benign simple steatosis to the progressive form nonalcoholic steatohepatitis (NASH), which is associated with fibrosis and an increased risk of progression to cirrhosis and hepatocellular carcinoma. NAFLD is the most common liver disease and is associated with extrahepatic comorbidities including a major cardiovascular disease burden. The non-invasive diagnosis of NAFLD and the identification of subjects at risk of progressive liver disease and cardio-metabolic complications are key in implementing personalized treatment schedules and follow-up strategies. In this review, we highlight the potential role of ultrasound semiquantitative scores for detecting and assessing steatosis severity, progression of NAFLD, and cardio-metabolic risk. Ultrasonographic scores of fatty liver severity act as sensors of cardio-metabolic health and may assist in selecting patients to submit to second-line non-invasive imaging techniques and/or liver biopsy.

Nonalcoholic Fatty Liver Disease: A Challenge from Mechanisms to Therapy

Focusing on previously published mechanisms of non-alcoholic fatty liver disease (NAFLD), their uncertainty does not always permit a clear elucidation of the grassroot alterations that are at the basis of the wide-spread illness, and thus curing it is still a challenge. There is somehow exceptional progress, but many controversies persist in NAFLD research and clinical investigation. It is likely that hidden mechanisms will be brought to light in the near future. Hereby, the authors present, with some criticism, classical mechanisms that stand at the basis of NAFLD, and consider contextually different emerging processes. Without ascertaining these complex interactions, investigators have a long way left ahead before finding an effective therapy for NAFLD beyond diet and exercise.

Ultrasound-based techniques for the diagnosis of liver steatosis

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of diffuse liver disease. An accurate estimate of the fat in the liver is important in the diagnostic work-up of patients with NAFLD because the degree of liver steatosis is linked to the metabolic syndrome and the cardiovascular risk. Ultrasound (US) B-mode imaging allows to subjectively estimate the fatty infiltration in the liver; however, it has a low performance for the detection of mild steatosis. Quantitative US is based on the analysis of the radiofrequency echoes detected by an US system, and it allows to calculate a backscatter coefficient or an attenuation coefficient or the sound speed. The estimation of the backscatter coefficient is rather cumbersome and requires the use of a phantom for addressing all sources of variability. Controlled attenuation parameter (CAP) available on the FibroScan® system (Echosens, France) measures the attenuation of the US beam. CAP is accurate in grading fatty infiltration-even though there is an overlap between consecutive grade of liver steatosis-and the values are not influenced by liver fibrosis. Several US manufacturers are developing or have already developed software for quantifying the attenuation of the US beam. Preliminary results show that proprietary technologies implemented in US systems seem more accurate than CAP for grading liver steatosis. Another available method for quantifying liver steatosis is based on the computation of the sound speed and the initial results appear promising.

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.

Long-term effect of bariatric surgery on resolution of nonalcoholic steatohepatitis (NASH): An external validation and application of a clinical NASH score

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is an important etiology of end-stage liver disease. Long-term effect of bariatric surgery in improvement of NASH is not clear.

OBJECTIVES

To validate a scoring system for predicting NASH in morbidly obese patients and using it to evaluate the long-term effect of bariatric surgery on NASH.

SETTING

Tertiary referral hospital, Taiwan.

METHODS

A new 5-point clinical NASH (C-NASH) score incorporating body mass index, alanine aminotransferase, and triglyceride was validated in a group of 307 bariatric patients (mean age 30.2 years, incorporating body mass index 45.0 kg/m²) with concurrent liver biopsy from 2003 to 2008. Remission of NASH in 5741 obese patients undergoing bariatric/metabolic surgery with long-term follow-up was then evaluated using the C-NASH score.

RESULTS

Among 307 patients with liver biopsy, the prevalence of NASH was 44.0%. At baseline, the NASH group had significantly worse fasting glucose levels, triglycerides, uric acid, aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, and glycated hemoglobin. The diagnostic sensitivity of C-NASH score was 84.4%, and the accuracy was 68.4%. Among 5741 bariatric patients, the prevalence of high risk for NASH evaluated by C-NASH score was 40.9%. Postoperative follow-up showed good weight loss and almost complete remission of high risk for NASH up to 10 years. Patients with gastric banding had less weight loss, higher mean level of C-NASH score, and a higher incidence of high risk for NASH compared with other procedures at follow-up.

CONCLUSION

This study demonstrated that improvement in C-NASH score suggesting remission of NASH is durable up to 10 years in all kinds of bariatric procedures.

Non-invasive diagnostic approach to non-alcoholic fatty liver disease: current evidence and future perspectives

Non-alcoholic fatty liver disease is a new epidemic liver disease, thus, its early diagnosis and the identification of those patients with the worst prognosis is mandatory. Liver biopsy is still the diagnostic gold standard, even if it is associated to a significant rate of complications; moreover, the interpretation of histological samples is not always univocal. Several non-invasive alternative scores have been proposed for the diagnostic approach to non-alcoholic fatty liver disease. This article evaluates the performance of the currently available non-invasive diagnostic strategies. The authors also suggest a potential diagnostic algorithm, with two or more non-invasive techniques, to increase the overall accuracy for identifying patients with worst prognosis, and to minimize the recourse to liver biopsy.

Clinical value of liver ultrasound for the diagnosis of nonalcoholic fatty liver disease in overweight and obese patients

BACKGROUND & AIMS

Liver ultrasound (US) is usually used in the clinical setting for the diagnosis and follow-up of patients with nonalcoholic fatty liver disease (NAFLD). However, no large study has carefully assessed its performance using a semiquantitative ultrasonographic scoring system in overweight/obese patients, in comparison to magnetic resonance spectroscopy ((1) H-MRS) and histology.

METHODS

We recruited 146 patients and performed: a liver US using a 5-parameter scoring system, a liver (1) H-MRS to quantify liver fat content, and a liver biopsy to assess histology. All measurements were repeated in a subgroup of patients (n = 62) after 18 months of follow-up.

RESULTS

The performance of liver US (parenchymal echo alone) was rather modest, and significantly worse than (1) H-MRS (AUROC: 0.82 [0.69-0.94] vs. 0.96 [0.90-1.00]; P = 0.04). However, the AUROC improved when different echographic parameters were taken into account (AUROC: 0.89 [0.83-0.96], P = 0.15 against (1) H-MRS). Optimum sensitivity for liver US was achieved at a liver fat content ≥12.5%, suggesting that below this threshold, liver US is less sensitive. Liver (1) H-MRS showed a high accuracy for the diagnosis of NAFLD, and correlated strongly with histological steatosis (r = 0.73, P < 0.0001). None of the imaging tests was adequate enough to predict changes over time in histology.

CONCLUSIONS

Despite its widespread use, liver US has several important limitations that healthcare providers should recognize, particularly because of its low sensitivity. Using a combination of echographic parameters, liver US showed a significant improvement in its diagnostic performance, but still was of limited value for monitoring treatment over time.

Role of ultrasound in the diagnosis and treatment of nonalcoholic fatty liver disease and its complications

We review the role of liver ultrasonography (US) and related techniques as non-invasive tools in predicting metabolic derangements, liver histology, portal hypertension and cardiovascular risk as well as allowing early diagnosis and management of hepatocellular carcinoma in patients with nonalcoholic fatty liver disease. In this setting, US detects fatty changes as low as ≥20% and hepatic steatosis identified ultrasonographically, in its turn, closely mirrors coronary and carotid atherosclerosis burden. Semi-quantitative US indices (to exclude nonalcoholic steatohepatitis) and sonoelastography (to quantify fibrosis) help in predicting liver histology and selecting patients to submit to liver biopsy. Surveillance for hepatocellular carcinoma conducted through biannual US is mandatory and US has a role in guiding locoregional treatment and in evaluating the efficacy of treatment. High-intensity focused ultrasound can be delivered with precision resulting in coagulative necrosis of hepatocellular carcinoma without puncturing the liver. Costs and inconveniences have so far hampered its diffusion.

Republished: Non-alcoholic fatty liver disease: non-invasive investigation and risk stratification

Non-alcoholic fatty liver disease (NAFLD) encompasses a histological spectrum of liver disease, from simple steatosis through to cirrhosis. As the worldwide rates of obesity have increased, NAFLD has become the commonest cause of liver disease in many developed countries, affecting up to a third of the population. The majority of patients have simple steatosis that carries a relatively benign prognosis. However, a significant minority have non-alcoholic steatohepatitis, and have increased liver related and cardiovascular mortality. Identifying those at risk of progressive disease is crucial. Liver biopsy remains the gold standard investigation for assessing stage of disease but its invasive nature makes it impractical for widespread use as a prognostic tool. Non-invasive tools for diagnosis and disease staging are required, reserving liver biopsy for those patients where it offers clinically relevant additional information. This review discusses the non-invasive modalities available for assessing steatosis, steatohepatitis and fibrosis. We propose a pragmatic approach for the assessment of patients with NAFLD to identify those at high risk of progressive disease who require referral to specialist services.

Noninvasive evaluation of NAFLD

A common clinical concern in patients with NAFLD is whether they have NASH or simple steatosis and, more importantly, what the stage of fibrosis is and whether the level of fibrosis has increased over time. Such concern is based on the fact that patients with NAFLD with advanced fibrosis are at greatest risk of developing complications of end-stage liver disease. Although it lacks sensitivity, ultrasonography is an accepted tool for steatosis screening. The controlled attenuation parameter or CAP seems a promising screening technique, but requires further validation. Cytokeratin-18 has been extensively validated, but it is an imperfect serum marker of NASH. Ultrasonography-based transient elastography can exclude advanced fibrosis and cirrhosis, but its main limitation is its reduced applicability in patients with NAFLD, which is not completely solved by use of the XL probe. Of the noninvasive serum markers, the NAFLD fibrosis score is the most validated and has appropriate accuracy in distinguishing patients with and without advanced fibrosis. Although noninvasive methods require further validation, they could be useful for selecting those patients with NAFLD who require a liver biopsy. This Review discusses the advantages and limitations of noninvasive methods for the management of adults with NAFLD, including diagnosis and quantification of steatosis, diagnosis of NASH and staging of hepatic fibrosis.

Non-alcoholic fatty liver disease: non-invasive investigation and risk stratification

Non-alcoholic fatty liver disease (NAFLD) encompasses a histological spectrum of liver disease, from simple steatosis through to cirrhosis. As the worldwide rates of obesity have increased, NAFLD has become the commonest cause of liver disease in many developed countries, affecting up to a third of the population. The majority of patients have simple steatosis that carries a relatively benign prognosis. However, a significant minority have non-alcoholic steatohepatitis, and have increased liver related and cardiovascular mortality. Identifying those at risk of progressive disease is crucial. Liver biopsy remains the gold standard investigation for assessing stage of disease but its invasive nature makes it impractical for widespread use as a prognostic tool. Non-invasive tools for diagnosis and disease staging are required, reserving liver biopsy for those patients where it offers clinically relevant additional information. This review discusses the non-invasive modalities available for assessing steatosis, steatohepatitis and fibrosis. We propose a pragmatic approach for the assessment of patients with NAFLD to identify those at high risk of progressive disease who require referral to specialist services.

Non-invasive diagnosis of non-alcoholic fatty liver disease. A critical appraisal

Non-alcoholic fatty liver disease (NAFLD) affects one in every three subjects in the occidental world. The vast majority will not progress, but a relevant minority will develop liver cirrhosis and its complications. The classical gold standard for diagnosing and staging NAFLD and assessing fibrosis is liver biopsy (LB). However, it has important sample error issues and subjectivity in the interpretation, apart from a small but real risk of complications. The decision to perform an LB is even harder in a condition so prevalent such as NAFLD, in which the probability of finding severe liver injury is low. In an attempt to overcome LB and to subcategorize patients with NAFLD in different prognoses allowing better management decisions, several non-invasive methods have been studied in the last decade. The literature is vast and confusing. This review will summarize which methods have been tested and how they perform, which tests are adequate for clinical practice and how they can change the management of these patients.

Ultrasonographic fatty liver indicator, a novel score which rules out NASH and is correlated with metabolic parameters in NAFLD

BACKGROUND

Differentiating steatosis from NASH is key in deciding treatment and follow-up schedules. We hypothesized that sonographic grading of steatosis will correlate with metabolic and pathologic changes of NASH.

METHODS

Fifty-three non-consecutive patients had a semi-quantitative evaluation of hepatic steatosis through ultrasonographic Fatty Liver Indicator (US-FLI) just prior to liver biopsy. All biopsies demonstrated NAFLD. US-FLI is a new scoring system ranging 2-8 based on the intensity of liver/kidney contrast, posterior attenuation of ultrasound beam, vessel blurring, difficult visualization of gallbladder wall, difficult visualization of the diaphragm and areas of focal sparing. NAFLD is diagnosed by the minimum score ≥2. Ultrasonographic findings were correlated with metabolic and histological data. Inter-observer US-FLI score agreement, evaluated by three different operators in 31 consecutive patients with steatosis, showed "almost perfect/substantial" agreement (P < 0.001).

RESULTS

US-FLI showed a positive correlation with HOMA, insulin, uric acid, ferritin, ALT and bilirubin and was associated with steatosis extent assessed histologically and histological features of NASH, except for fibrosis. US-FLI was an independent predictor of NASH (OR 2.236; P = 0.007) and a US-FLI < 4 had a high negative predictive value (94%) in ruling out the diagnosis of severe NASH according to Kleiner's criteria.

CONCLUSION

Data confirm the hypothesis that US-FLI significantly correlates with metabolic derangements and individual pathologic criteria for NASH and may better select patients for liver biopsy.

The PNPLA3 I148M polymorphism is associated with insulin resistance and nonalcoholic fatty liver disease in a normoglycaemic population

BACKGROUND AND AIMS

The adiponutrin/patatin-like phospholipase-3 (PNPLA3) I148M polymorphism has recently been found to contribute to differences in hepatic lipid content. Nonalcoholic fatty liver disease (NAFLD) has recently been considered a hepatic component of insulin resistance and a risk factor in the emergence of type 2 diabetes. However, whether there is an association between PNPLA3 I148M and insulin resistance and NAFLD in a normoglycaemic population is still unknown.

METHODS

This study enrolled 156 normoglycaemic individuals with NAFLD and 723 controls. All participants received complete biochemical and clinical workups including liver ultrasonography. They were then genotyped for the PNPLA3 I148M polymorphism.

RESULTS

We found significant differences in the genotype and the dominant model of the PNPLA3 I148M polymorphism between the NAFLD groups and the controls (P=0.018 and P=0.01 respectively). Furthermore, there was a dose effect of the PNPLA3 I148M genotype, in that CG heterozygotes had a risk of NAFLD between CC and GG homozygotes [adjusted odds ratio (OR)=2.03, 95% confidence interval (CI)=1.23-3.375 for the GG genotype and adjusted OR=1.55, 95% CI=1.02-2.35 for the CG genotype]. The dominant model of the PNPLA3 I148M polymorphism showed higher waist circumference, fasting insulin, Homeostasis Model Assessment (HOMA-IR), alanine aminotransferase concentrations and ferritin level. Multivariate analysis showed the PNPLA3 I148M polymorphism to be independently and significantly associated with NAFLD in our normoglycaemic participants.

CONCLUSION

This study reports an association between the PNPLA3-I148M polymorphism and insulin resistance and NAFLD in a normoglycaemic population.