Controlled attenuation parameter for non-invasive assessment of hepatic steatosis in Chinese patients

Magnetic resonance imaging and transient elastography in the management of Nonalcoholic Fatty Liver Disease (NAFLD)

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and cirrhosis worldwide and the second most common cause of liver transplantation in major medical centers. Because liver steatosis and fibrosis severity are related to disease morbidity and mortality, the extent of disease, and disease progression, they need to be assessed and monitored. In addition, innovation with new drug developments requires disease staging and monitoring in both phase 2 and 3 clinical trials. Currently, disease assessment in both clinical practice and research is mostly performed by liver biopsy, an invasive, procedure with risks. Noninvasive, highly accurate tests are needed that could be used in clinical trials as surrogate endpoints and in clinical practice for monitoring patients. Area Covered: We discuss noninvasive tests, transient elastography (TE) with controlled attenuation parameter (CAP), magnetic resonance imaging (MRI), and MR elastography (MRE), summarize the available evidence of their usefulness for assessing steatosis and fibrosis. Therefore they could be used as clinical trials outcomes and in disease monitoring in clinical practice. Expert Commentary: TE with CAP, MRI and MRE are highly accurate noninvasive diagnostic tools for quantifying hepatic steatosis and fibrosis. Therefore they could be used as clinical trials outcomes and in disease monitoring in clinical practice.

Controlled attenuation parameter using the FibroScan® XL probe for quantification of hepatic steatosis for non-alcoholic fatty liver disease in an Asian population

BACKGROUND

The FibroScan® XL probe reduces failure of liver stiffness measurement (LSM) and unreliable results in obese patients.

OBJECTIVE

The objective of this article is to evaluate the accuracy of controlled attenuation parameter (CAP) obtained using the XL probe for the estimation of hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

Adult NAFLD patients with a liver biopsy within six months were included and were examined with the FibroScan® M and XL probes. Histopathological findings were reported according to the Non-Alcoholic Steatohepatitis Clinical Research Network Scoring System. Participants who did not have fatty liver on ultrasonography were recruited as controls.

RESULTS

A total of 57 NAFLD patients and 22 controls were included. The mean age of the NAFLD patients and controls was 50.1 ± 10.4 years and 20.2 ± 1.3 years, respectively (p = 0.000). The mean body mass index was 30.2 ± 5.0 kg per m2 and 20.5 ± 2.4 kg per m2, respectively (p = 0.000). The distribution of steatosis grades were: S0, 29%; S1, 17%; S2, 35%; S3, 19%. The AUROC for estimation of steatosis grade ≥ S1, S2 and S3 was 0.94, 0.80 and 0.69, respectively, using the M probe, and 0.97, 0.81 and 0.67, respectively, using the XL probe.

CONCLUSION

CAP obtained using the XL probe had similar accuracy as the M probe for the estimation of hepatic steatosis in NAFLD patients.

Lobeglitazone, a Novel Thiazolidinedione, Improves Non-Alcoholic Fatty Liver Disease in Type 2 Diabetes: Its Efficacy and Predictive Factors Related to Responsiveness

Despite the rapidly increasing prevalence of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes (T2D), few treatment modalities are currently available. We investigated the hepatic effects of the novel thiazolidinedione (TZDs), lobeglitazone (Duvie) in T2D patients with NAFLD. We recruited drug-naïve or metformin-treated T2D patients with NAFLD to conduct a multicenter, prospective, open-label, exploratory clinical trial. Transient liver elastography (Fibroscan®; Echosens, Paris, France) with controlled attenuation parameter (CAP) was used to non-invasively quantify hepatic fat contents. Fifty patients with CAP values above 250 dB/m were treated once daily with 0.5 mg lobeglitazone for 24 weeks. The primary endpoint was a decline in CAP values, and secondary endpoints included changes in components of glycemic, lipid, and liver profiles. Lobeglitazone-treated patients showed significantly decreased CAP values (313.4 dB/m at baseline vs. 297.8 dB/m at 24 weeks; P = 0.016), regardless of glycemic control. Lobeglitazone improved HbA(1C) values (7.41% [57.5 mM] vs. 6.56% [48.2 mM]; P < 0.001), as well as the lipid and liver profiles of the treated patients. Moreover, multivariable linear regression analysis showed that hepatic fat reduction by lobeglitazone was independently associated with baseline values of CAP, liver stiffness, and liver enzymes, and metformin use. Lobeglitazone treatment reduced intrahepatic fat content, as assessed by transient liver elastography, and improved glycemic, liver, and lipid profiles in T2D patients with NAFLD. Further randomized controlled trials using liver histology as an end point are necessary to evaluate the efficacy of lobeglitazone for NAFLD treatment.

Diagnostic Accuracy of Controlled Attenuation Parameter for Detecting Hepatic Steatosis in Patients with Chronic Liver Disease

Introduction

Controlled attenuation parameter (CAP), measured by transient elastography, has been suggested as a noninvasive method for the detection and quantification of steatosis. We aimed to assess the accuracy of CAP to detect steatosis in patients with chronic liver disease (CLD) compared with liver histology and to evaluate factors that correlate with the CAP value.

Methods

Patients with CLD who underwent liver biopsy and simultaneous CAP determination were consecutively enrolled. CAP was measured using the M probe of FibroScan® (Echosens, Paris, France). Histologically, steatosis was categorized as absent (S0: <5%), mild (S1: 5-33%), moderate (S2: 34-66%) and severe (S3: >66% of all hepatocytes).

Results

We analyzed 159 patients with CLD (61% men, mean age 47.9 ± 12.9 years). We found a positive correlation between CAP and steatosis in histology (r_s = 0.869, p < 0.001), arterial hypertension (r_s = 0.222, p = 0.005), type 2 diabetes mellitus (r_s = 0.279, p < 0.001), body mass index (BMI; r_s = 0.533, p < 0.001), total cholesterol (r_s = 0.442, p < 0.001), triglycerides (r_s = 0.272, p = 0.001), and non-alcoholic fatty liver disease (NAFLD; r_s = 0.588, p < 0.001). In the multivariate analysis, BMI >25 (odds ratio [OR] 48.4, 95% confidence interval [CI] 23.78-72.95, p < 0.001), serum total cholesterol (OR 3.803, 95% CI 2.203-13.889, p = 0.008), and NAFLD etiology (OR 40.8, 95% CI 15.01-66.66, p = 0.002) were independently associated with higher CAP values. We did not find any significant correlation between CAP and the grade of necroinflammatory activity (r_s = 0.063, p = 0.808) or fibrosis (r_s = 0.071, p = 0.713) in histology and with alanine aminotransferase (r_s = 0.190, p = 0.356) or aspartate aminotransferase (r_s = 0.117, p = 0.142). Optimal CAP cutoff values for detecting steatosis ≥S1, ≥S2, and ≥S3 were 206.5, 232.5, and 282.5 dB/m, respectively. CAP performance was 0.822, 0.956, and 0.976 for diagnosing steatosis ≥S1, ≥S2, and ≥S3, respectively.

Conclusions

CAP had an excellent diagnostic accuracy for the detection of steatosis in diverse CLD patients. A CAP value cutoff of <282.5 dB/m excludes severe steatosis ≥S3 with an accuracy of 98%.

Hypertension and non-alcoholic fatty liver disease proven by transient elastography

AIM

The relationship between non-alcoholic fatty liver disease (NAFLD) and hypertension is poorly understood. In the present study, we aimed to assess the relationship between essential hypertension and NAFLD, by using a new diagnostic tool, transient elastography (TE).

METHODS

We enrolled 836 subjects in this study. All subjects underwent a comprehensive questionnaire survey and blood test. Each patient had undergone TE to detect the controlled attenuation parameter, which was used to and quantify liver steatosis with the help of TE.

RESULTS

Participants with hypertension showed a higher prevalence of NAFLD defined by TE (P < 0.05). After adjusting for body mass index (BMI), aspartate aminotransferase (AST), alanine aminotransferase, triglycerides, total cholesterol, and high-density lipoprotein cholesterol, the odds ratio for NAFLD, comparing the grade 3 group (systolic blood pressure level ≥ 180 mmHg and/or diastolic blood pressure level ≥ 110 mmHg) with the normal group, was 1.476 (95% confidence interval, 1.166-2.551). A stepwise multivariate linear regression analysis (R²  = 0.084, P = 0.043) retained NAFLD, BMI, and AST as significant predictors of the systolic blood pressure levels. Additionally, stepwise multivariate linear regression analysis (R²  = 0.199, P = 0.037) retained NAFLD, controlled attenuation parameter, BMI, triglycerides, and high-density lipoprotein cholesterol as significant predictors of diastolic blood pressure levels. In addition, BMI, AST, and alanine aminotransferase were associated with systolic blood pressure levels among individuals with NAFLD; BMI, AST, and total cholesterol were associated with diastolic blood pressure levels among individuals with NAFLD.

CONCLUSION

The main finding of our study is that hypertensive patients have a higher prevalence of NAFLD defined by TE, and NAFLD is independently associated with hypertension and blood pressure category.

MRI and MRE for non-invasive quantitative assessment of hepatic steatosis and fibrosis in NAFLD and NASH: Clinical trials to clinical practice

Non-alcoholic fatty liver disease (NAFLD) represents one of the most common causes of chronic liver disease, and its prevalence is rising worldwide. The occurrence of non-alcoholic steatohepatitis (NASH) is associated with a substantial increase in disease related morbidity and mortality. Accordingly, there has been a surge of innovation surrounding drug development in an effort to off-set the natural progression and long-term risks of this disease. Disease assessment within clinical trials and clinical practice for NAFLD is currently done with liver biopsies. Liver biopsy-based assessments, however, remain imprecise and are not without cost or risk. This carries significant implications for the feasibility and costs of bringing therapeutic interventions to market. A need therefore arises for reliable and highly accurate surrogate end-points that can be used in phase 2 and 3 clinical trials to reduce trial size requirements and costs, while improving feasibility and ease of implementation in clinical practice. Significant advances have now been made in magnetic resonance technology, and magnetic resonance imaging (MRI) and elastrography (MRE) have been demonstrated to be highly accurate diagnostic tools for the detection of hepatic steatosis and fibrosis. In this review article, we will summarize the currently available evidence regarding the use of MRI and MRE among NAFLD patients, and the evolving role these surrogate biomarkers will play in the rapidly advancing arena of clinical trials in NASH and hepatic fibrosis. Furthermore, we will highlight how these tools can be readily applied to routine clinical practice, where the growing burden of NAFLD will need to be met with enhanced monitoring algorithms.

Non-invasive diagnosis of hepatic steatosis

Non-invasive diagnosis and quantification of hepatic steatosis rely on two different but complementary approaches: biomarkers or imaging techniques, either ultrasound-based such as liver ultrasonography and controlled attenuation parameter (CAP), or computed tomography (CT) and magnetic resonance imaging (MRI). Scores for the detection of steatosis have not gained much popularity in clinical practice so far. CAP, using the M probe, is the most promising technique but needs to be implemented with the XL probe and compared to ultrasound that, despite its limitations, remains the most widely used method. CT, owing to its low sensitivity and the fact that it involves a potential radiation hazard, is inappropriate. Finally, proton density fat fraction measurement by MRI is currently the most accurate and sensitive imaging method, simpler and more practical than magnetic resonance spectroscopy, but restricted, up to now, just to research and clinical trials.

Controlled attenuation parameter is correlated with actual hepatic fat content in patients with non-alcoholic fatty liver disease with none-to-mild obesity and liver fibrosis

AIM

Non-invasive steatosis-quantifying methods are required for non-alcoholic fatty liver disease (NAFLD) patients in order to monitor disease severity and assess therapeutic efficacy. Controlled attenuation parameter (CAP) evaluated with vibration-controlled transient elastography can predict the presence of steatosis, but its application to absolute hepatic fat quantitation remains unclear. The aim of this st\udy was to examine whether CAP is correlated with real hepatic fat content in NAFLD patients.

METHODS

Eighty-two NAFLD patients who had undergone percutaneous liver biopsy were enrolled. CAP was measured using FibroScan(®) just before liver biopsy. The percentage of fat droplet area to hepatocyte area in biopsied specimen was determined morphometrically using computerized optical image analyzing system. The correlation between CAP and liver histology was examined.

RESULTS

CAP showed an excellent correlation with actual liver fat percentage in the NAFLD patients with body mass index (BMI) of less than 28 kg/m(2) (r = 0.579, P < 0.0001), especially less than 25 kg/m(2) (r = 0.708, P < 0.01), but the meaningful correlation disappeared in the patients with BMI of 28 kg/m(2) or more. In the patients with BMI of less than 28 kg/m(2) , CAP quantitativeness was affected by the presence of stage 2-4 fibrosis, but not the presence of hepatocyte ballooning and severity of lobular inflammation.

CONCLUSION

CAP may be a promising tool for quantifying hepatic fat content in NAFLD patients with none-to-mild obesity and liver fibrosis. Further improvement of CAP performance is needed for the NAFLD patients with BMI of more than 28 kg/m(2) or significant hepatic fibrosis.

Advances in noninvasive methods for diagnosing nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease (NAFLD), one of the most common chronic liver diseases worldwide, has been increasing. In terms of pathological changes, NAFLD can be divided into simple steatosis, nonalcoholic steatohepatitis (NASH) and liver cirrhosis. Hepatocyte damage and inflammatory activity are the main characteristics for evaluating the progress of liver disease. Early and effective diagnosis of the disease is quite important. Pathological findings based on liver biopsy or resected specimens are considered the gold standard for diagnosing and staging steatosis, fibrosis and cirrhosis; however, it is invasive and may lead to related complications. Non-imaging methods such as clinical features and biochemical tests, and imaging methods such as ultrasonography, FibroScan, computed tomography and magnetic resonance imaging are the commonly used noninvasive alternatives, being relatively novel, safe and reliable. In this review, we summarized the benefits and shortcomings of these non-invasive methods for the evaluation of NAFLD.

Transient elastography (FibroScan®) with controlled attenuation parameter in the assessment of liver steatosis and fibrosis in patients with nonalcoholic fatty liver disease - Where do we stand?

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Currently, the routinely used modalities are unable to adequately determine the levels of steatosis and fibrosis (laboratory tests and ultrasonography) or cannot be applied as a screening procedure (liver biopsy). Among the non-invasive tests, transient elastography (FibroScan^®, TE) with controlled attenuation parameter (CAP) has demonstrated good accuracy in quantifying the levels of liver steatosis and fibrosis in patients with NAFLD, the factors associated with the diagnosis and NAFLD progression. The method is fast, reliable and reproducible, with good intra- and interobserver levels of agreement, thus allowing for population-wide screening and disease follow-up. The initial inability of the procedure to accurately determine fibrosis and steatosis in obese patients has been addressed with the development of the obese-specific XL probe. TE with CAP is a viable alternative to ultrasonography, both as an initial assessment and during follow-up of patients with NAFLD. Its ability to exclude patients with advanced fibrosis may be used to identify low-risk NAFLD patients in whom liver biopsy is not needed, therefore reducing the risk of complications and the financial costs.

Controlled attenuation parameter for the detection of hepatic steatosis in patients with chronic hepatitis B

BACKGROUND

Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing liver steatosis based on vibration-controlled transient elastography. The primary objective of this study was to assess CAP performance and determine the cut-off values for the diagnosis of hepatic steatosis in patients with chronic hepatitis B (CHB) using liver biopsy as a gold standard. The second objective was to apply the cut-off values found in the first cohort to a larger cohort to compare the performance of CAP and ultrasonography.

METHODS

Overall, 189 patients with CHB who underwent liver biopsy and CAP detection and 1707 patients with CHB and CAP who underwent abdominal ultrasonography were prospectively enrolled. The performance of CAP for evaluating hepatic steatosis compared with liver biopsy was calculated using the area under the receiver operating characteristic curve (AUROC).

RESULTS

In the 189 patients who underwent liver biopsy, the cut-offs for the CAP with steatosis S ≥ 1, S ≥ 2 and S ≥ 3 were 222 dB/m, 247 dB/m and 274 dB/m, respectively, and the AUROC were 0.88 (95% confidence interval [CI] = 0.82-0.95), 0.92 (95% CI = 0.87-0.97) and 0.94 (95% CI = 0.90-0.99), respectively. After applying the cut-offs above to the 1707 patients, it was found that CAP had a good concordance with abdominal ultrasonography with steatosis grade > S2. On multivariate analysis, body mass index (p < 0.001), triglyceride level (p < 0.001) and fasting glucose level (p = 0.001) were independent risk factors of CAP.

CONCLUSIONS

CAP had high diagnostic performance for evaluating hepatic steatosis in patients with CHB and had a good concordance with abdominal ultrasonography.

Factors influencing controlled attenuation parameter measured by Fibrotouch in healthy individuals

AIM: To explore the factors influencing controlled attenuation parameter (CAP) obtained by FibroTouch in the general population.

METHODS: This study recruited 664 healthy individuals, and CAP measurement was conducted by Fibrotouch examination. Blood lipids, blood biochemical indexes, the classification results of fatty liver by ultrasound, gender, age and body mass index (BMI) were assessed. Multiple linear regression analysis was used for statistical analysis.

RESULTS: Multiple liner regression analysis showed that CAP value was significantly correlated with the classification results of fatty liver by ultrasound, BMI and alanine transaminase (ALT) (F = 228.89, P < 0.0001; standard regression coefficient of the classification results of fatty liver by ultrasound, β = 0.55, P < 0.0001; of BMI, β = 0.31, P < 0.0001; of ALT, β = 0.08, P = 0.0279), and the regression equation established after multiple linear regression analysis was CAP = 118.0044 + 17.2832 × the classification results of fatty liver by ultrasound + 3.3909 × BMI + 0.1919 × ALT.

CONCLUSION: CAP value might be affected by BMI, the classification results of fatty liver by ultrasound and serum ALT levels in the general population.

Association of Circulating Serum miR-34a and miR-122 with Dyslipidemia among Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) covers a spectrum of diseases from simple steatosis to non-alcoholic steatohepatitis, with approximately 20% risk of progressing to fibrosis and cirrhosis. The aim of this study was to compare the relative expression levels of circulating miR-21, miR-34a, miR-122, miR-125b and miR-375 between healthy controls and NAFLD patients, and to assess the feasibility of microRNAs as potential biomarkers for NAFLD. A cross-sectional study was conducted to evaluate circulating serum miRNAs as potential diagnostic markers for NAFLD. Twenty-eight clinically diagnosed and histologically-confirmed NAFLD patients, as well as 36 healthy controls were enrolled in this study. The relative expression of serum microRNAs were calculated using the comparative cycle threshold with spiked-in C. elegans miR-39 as exogenous internal control. Serum levels of miR-34a and miR-122 were significantly higher in NAFLD patients than in healthy controls (P = <0.0001). Positive correlations were observed between serum miR-34a with very low density lipoprotein cholesterol (VLDL-C) and triglyceride levels. However, the expression levels of miR-34a and miR-122 did not correlate with the histological features of NAFLD. Interestingly, receiver operating characteristic (ROC) curve analysis revealed that miR-34a and miR-122 are potential markers for discriminating NAFLD patients from healthy controls with an area under the curve (AUC) values of 0.781 and 0.858, respectively. Serum levels of miR-34a and miR-122 were found to be significantly higher among NAFLD patients, and were positively correlated with VLDL-C and triglyceride levels. Thus, circulating miR-34a and miR-122 can be used as potential biomarkers for discriminating NAFLD patients from healthy controls. Larger cohorts are required to validate the utility of miR-34a and miR-122 in monitoring liver injury.

Liver Steatosis Assessed by Controlled Attenuation Parameter (CAP) Measured with the XL Probe of the FibroScan: A Pilot Study Assessing Diagnostic Accuracy

To assess liver steatosis, the controlled attenuation parameter (CAP; giving an estimate of ultrasound attenuation ∼3.5 MHz) is available with the M probe of the FibroScan. We report on the adaptation of the CAP for the FibroScan XL probe (center frequency 2.5 MHz) without modifying the range of values (100-400 dB/m). CAP validation was successfully performed on Field II simulations and on tissue-mimicking phantoms. In vivo performance was assessed in a cohort of 59 patients spanning the range of steatosis. In vivo reproducibility was good and similar with both probes. The area under receiver operative characteristic curve was equal to 0.83/0.84 and 0.92/0.91 for the M/XL probes to detect >2% and >16% liver fat, respectively, as assessed by magnetic resonance imaging. Patients can now be assessed simultaneously for steatosis and fibrosis using the FibroScan, regardless of their morphology.

Noninvasive assessment of alcoholic liver disease using unidimensional transient elastography (Fibroscan®)

Unidimensional transient elastography (TE) is a noninvasive technique, which has been increasingly used in the assessment of diffuse liver diseases. This paper focuses on reviewing the existing data on the use of TE in the diagnosis of fibrosis and in monitoring disease progression in alcoholic liver disease, on the factors that may influence the result of fibrosis prediction, and last but not least, on its potential use in assessing the steatosis degree. Therefore, this field is far from being exhausted and deserves more attention. Further studies are required, on large groups of biopsied patients, in order to find answers to all the remaining questions in this field.

Impact of skin capsular distance on the performance of controlled attenuation parameter in patients with chronic liver disease

BACKGROUND & AIMS

Controlled attenuation parameter (CAP) is a non-invasive method for evaluating hepatic steatosis. However, larger skin capsular distance (SCD) can affect the accuracy. The aim of this study was to investigate the impact of SCD on the diagnostic performance of CAP and liver stiffness measurement (LSM).

METHODS

Of 101 patients with non-alcoholic fatty liver disease (NAFLD) and 280 patients with chronic hepatitis B (CHB) who underwent liver biopsy were prospectively recruited. CAP, LSM and SCD were performed using FibroScan with M probe. The areas under receiver operating characteristics curves (AUROCs) were calculated to determine the diagnostic efficacy. The optimal thresholds were defined by the maximum Youden index.

RESULTS

SCD (B 30.34, P < 0.001) and hepatic steatosis (B 23.04, P < 0.001) were independently associated with CAP by multivariate analysis. The AUROCs were slightly higher for SCD <25 mm compared to those for SCD ≥25 mm for steatosis ≥5% (0.88 vs. 0.81), >33% (0.90 vs. 0.85) and >66% (0.84 vs. 0.72). For SCD <25 mm, the optimal CAP cut-offs for differentiating steatosis ≥5%, >33% and >66% were 255.0 dB/m, 283.5 dB/m and 293.5 dB/m. However, cut-offs were elevated by approximately 60-70 dB/m for SCD ≥25 mm. When stratified by fibrosis grade, LSM was significantly affected by SCD ≥25 mm for advanced fibrosis (≥F3) in NAFLD, but not in CHB.

CONCLUSION

CAP is a promising tool for detecting and quantifying hepatic steatosis. SCD ≥25 mm may cause overestimation of steatosis. Similarly, SCD ≥25 mm affects the detection of advanced fibrosis by LSM in NAFLD patients.

Controlled attenuation parameter for assessment of hepatic steatosis grades: a diagnostic meta-analysis

AIM

to evaluate the performance and accuracy of Controlled attenuation parameter CAP for hepatic steatosis detection.

METHODS

PubMed, EBSCO, Elsevier Science, Ovid, and Wiley were selected to search studies until August 31, 2014. Quality Assessment of Diagnostic Accuracy Studies checklist was used to assess the quality of included studies. Heterogeneity was evaluated using Q test. Sensitivity, specificity, diagnostic odds ratio (DOR), and the area under curve (AUC) with its 95% confidence intervals (CIs) were calculated to evaluate the accuracy of CAP for assessment of hepatic steatosis stage (≥ S1, ≥ S2 and ≥ S3).

RESULTS

Totally 11 studies (13 cohorts) with high methodological qualities were identified. The summary point estimations with 95% CIs of sensitivity, specificity, AUC and DORs were 0.78 (0.71, 0.84), 0.79 (0.70, 0.86), 0.86 (0.82, 0.88), and 14 (7, 27) for ≥ S1; 0.82 (0.74, 0.88), 0.79 (0.73, 0.85), 0.88 (0.85, 0.90) and 18 (10, 30) for ≥ S2; 0.86 (0.82, 0.89), 0.89 (0.86, 0.92), 0.94 (0.91, 0.96) and 51 (35, 76) for ≥ S3. Significant heterogeneity was found among the studies in ≥ S1 and ≥ S3. Threshold effect was existed in ≥ S3, but not in ≥ S1 and ≥ S2. Publication bias was not existed in ≥ S1 and ≥ S2 except ≥ S3.

CONCLUSION

CAP provides good sensitivity and specificity for detection of ≥ S1, ≥ S2, and ≥ S3 steatosis. However, future studies with large samples are still necessary to confirm the clinical application.

Ultrasound imaging of the liver and bile ducts - expectations of a clinician

Since diseases of the liver and bile ducts are common, a clinician is faced by the need to implement an appropriate diagnostic process. It is necessary to apply diagnostic methods that enable appropriate assessment of the most common pathologies of the liver, i.e. fibrosis, steatosis and focal lesions, as well as initial assessment of the bile ducts. These goals can be achieved using ultrasound methods based on conventional sonography, contrast-enhanced sonography and elastography. The assessment of fatty liver and bile duct dilatation using ultrasound reaches satisfactory levels of sensitivity and specificity. The usage of contrast agents enables unambiguous differentiation between benign and malignant focal lesions, frequently allowing them to be identified accurately without the assistance of other imaging modalities. Elastography has enabled reliable assessment of liver fibrosis. Its results are comparable to those of the standard method, i.e. liver biopsy.

Association of adiponectin gene polymorphism with nonalcoholic fatty liver disease in Taiwanese patients with type 2 diabetes

Objective

Patients with type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) have a higher prevalence of cardiovascular diseases. In this study we investigated the frequency of single nucleotide polymorphisms (SNPs) of several candidate genes associated with NAFLD in Taiwanese patients with type 2 diabetes mellitus (DM) and NAFLD and in those with DM but without fatty liver disease.

Methods

We enrolled 350 patients with type 2 DM and NAFLD and 209 patients with DM but without NAFLD. Body mass index (BMI), % body fat (% BF), glycated hemoglobin (HbA1c), high molecular weight (HMW) isoform of adiponectin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) levels were measured. Thirteen SNPs in 5 genes (adiponectin, leptin, peroxisome proliferator-activated receptor alpha, adiponutrin/patatin-like phospholipase domain-containing protein 3 and peroxisome proliferator-activated receptor γ co-activator 1α ) were measured.

Results

Only adiponectin rs266729 polymorphism was associated with susceptibility to NAFLD (p = 0.001). Subgroup analysis revealed that the proportion of subjects with homozygous genotype GG was higher in patients with NAFLD (31%) than in controls (11%) and that the proportions of heterozygous CG and homozygous CC were higher in controls (37% and 52%, respectively) than in patients with NAFLD (33% and 36%, respectively). Patients with NAFLD carrying the GG genotype of rs266729 showed significantly lower serum HMW adiponectin levels than patients carrying the GC or CC genotype (3.75±0.37 vs. 3.99±0.66 vs. 4.79±0.58 μg/ml, p< 0.001). Body fat and serum HMW adiponectin levels were the strongest predictors of developing NAFLD (p < 0.001 and 0.004, respectively).

Conclusions

In patients with type 2 diabetes gene polymorphism of adiponectin rs266729 is associated with risk of NAFLD. G allele of rs266729 is associated with hypoadiponectinemia. Low serum adiponectin level may precipitate liver steatosis in patients with type 2 diabetes.

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.

Non-invasive methods for the diagnosis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease and includes simple steatosis and nonalcoholic steatohepatitis (NASH). Since NASH progresses to cirrhosis more frequently and increases liver-related and cardiovascular disease risk substantially more than simple steatosis, there is a great need to differentiate the two entities. Liver biopsy is the gold standard for the diagnosis of NAFLD but its disadvantages, including the risk of complications and sampling bias, stress the need for developing alternative diagnostic methods. Accordingly, several non-invasive markers have been evaluated for the diagnosis of simple steatosis and NASH, including both serological indices and imaging methods. The present review summarizes the current knowledge on the role of these markers in the diagnosis of NAFLD. Current data suggest that ultrasound and the fibrosis-4 score are probably the most appealing methods for detecting steatosis and for distinguishing NASH from simple steatosis, respectively, because of their low cost and relatively high accuracy. However, currently available methods, both serologic and imaging, cannot obviate the need for liver biopsy for diagnosing NASH due to their substantial false positive and false negative rates. Therefore, the current role of these methods is probably limited in patients who are unwilling or have contraindications for undergoing biopsy.

Normal controlled attenuation parameter values: a prospective study of healthy subjects undergoing health checkups and liver donors in Korea

BACKGROUND/AIMS

The controlled attenuation parameter (CAP) is a noninvasive method of assessing hepatic steatosis. We defined the normal range of CAP values in healthy subjects and evaluated the associated factors.

METHODS

CAP values were measured in a cohort of healthy subjects who were screened as living liver transplantation donors and those who underwent health checkups. Subjects with current or a history of chronic liver disease, abnormalities on liver-related laboratory tests, or fatty liver on ultrasonography or biopsy were excluded.

RESULTS

The mean age of the 264 recruited subjects (131 males and 133 females; 76 potential liver donors and 188 subjects who had undergone health checkups) was 49.2 years. The mean CAP value was 224.8 ± 38.7 dB/m (range 100.0-308.0 dB/m), and the range of normal CAP values (5th-95th percentiles) was 156.0-287.8 dB/m. The mean CAP value was significantly higher in the health checkup than in the potential liver donor group (227.5 ± 42.0 vs. 218.2 ± 28.3 dB/m, P = 0.040). CAP values did not differ significantly according to gender or age in either group (all P > 0.05). In a multivariate linear regression analysis, body mass index (β = 0.271, P = 0.024) and triglyceride levels (β = 0.348, P = 0.008) were found to be independently associated with CAP values.

CONCLUSION

We determined the normal range of CAP values and found that body mass index and triglyceride levels were associated with the CAP values of healthy subjects.

Controlled attenuation parameter for noninvasive assessment of hepatic steatosis using Fibroscan®: validation in chronic hepatitis B

BACKGROUND AND AIM

The controlled attenuation parameter (CAP) using transient elastography (TE) was validated in chronic hepatitis C to evaluate hepatic steatosis; however, limited data are available on chronic hepatitis B (CHB). Therefore, we assessed the accuracy and the efficacy of CAP for the detection of steatosis in CHB.

METHODS

Consecutive CHB patients underwent liver biopsy and liver stiffness measurements (LSM) with simultaneous CAP determination using the M probe of the TE. The area under the receiver operating characteristics curve (AUROC) was used to evaluate the performance of CAP in diagnosing steatosis compared with biopsy.

RESULTS

A total of 340 patients were included: 60 % were male, the median age was 37 years; the body mass index (BMI) was ≥ 28 kg/m(2) for 14 % of the subjects; and the distribution of the steatosis grade was S0 58.2 %, S1 34.2 %, S2 5.0 % and S3 2.6 %. The median (range) of CAP was 218 (100-400) dB/m, and CAP correlated with the BMI (ρ = 3.622) and steatosis grade (ρ = 29.203) according to a multivariate analysis (both P < 0.001). CAP could detect the different grades of steatosis: ≥ S1 with AUROC of 0.81 at a cutoff of 224 dB/m, ≥ S2 with AUROC of 0.90 at a cutoff of 236 dB/m and ≥ S3 with AUROC of 0.97 at a cutoff of 285 dB/m. Furthermore, the LSM and fibrosis and activity grades on biopsy did not influence the CAP performance.

CONCLUSIONS

CAP presented excellent diagnostic performance for severe steatosis with high sensitivity and specificity in Chinese patients with CHB.