Controlled attenuation parameter (CAP) for detection of hepatic steatosis in patients with chronic liver diseases: a prospective study of a native Korean population

Relationship between Controlled Attenuation Parameter and Hepatic Steatosis as Assessed by Ultrasound in Alcoholic or Nonalcoholic Fatty Liver Disease

Background/Aims

The aim of this study was to evaluate the relationship between controlled attenuation parameter (CAP) and hepatic steatosis, as assessed by ultrasound (US) in patients with alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD).

Methods

Patients with either ALD or NAFLD who were diagnosed with fatty liver with US and whose CAP scores were measured, were retrospectively enrolled in this study. The degree of hepatic steatosis assessed by US was categorized into mild (S1), moderate (S2), and severe (S3).

Results

A total of 186 patients were included: 106 with NAFLD and 80 with ALD. Regarding hepatic steatosis, the CAP score was significantly correlated with US (ρ=0.580, p<0.001), and there was no significant difference between the NAFLD and ALD groups (ρ=0.569, p<0.001; ρ=0.519, p<0.001; p=0.635). Using CAP, area under receiver operating characteristic curves for ≥S2 and ≥S3 steatosis were excellent (0.789 and 0.843, respectively). For sensitivity ≥90%, CAP cutoffs for the detection of ≥S2 and ≥S3 steastosis were separated with a gap of approximately 35 dB/m in all patients and in each of the NAFLD and ALD groups.

Conclusions

The CAP score is well correlated with hepatic steatosis, as assessed by US, in both ALD and NAFLD.

The clinical value of controlled attenuation parameter for the noninvasive assessment of liver steatosis

BACKGROUND & AIMS

Ultrasound is the imaging modality most widely utilized in the general population for diagnostic purposes. Controlled attenuation parameter is a novel noninvasive method for assessing steatosis. Our aim was to investigate whether the clinical value of controlled attenuation parameter in patients referred for abdominal ultrasound examinations is affected by liver fibrosis.

METHODS

Consecutive patients referred for abdominal ultrasound examinations were enrolled. Controlled attenuation parameter and liver stiffness were assessed with the FibroScan (Echosens, France). Liver fibrosis was staged according to published cutoffs of liver stiffness measurements. Pearson's or Spearman's rank correlation coefficient was used to test the association between two study variables. Optimal cutoff of controlled attenuation parameter for diagnosing liver steatosis (S≥2) was 256 dB/m. The diagnostic performance and accuracy of dichotomized controlled attenuation parameter, ultrasound and body mass index were analysed using the imperfect gold standard methodology.

RESULTS

A total of 726 subjects (464 males and 262 females) were studied. Five hundred and eight-nine (81.1%) patients were affected by chronic viral hepatitis. Correlation of controlled attenuation parameter with ultrasound score was 0.48 and 0.57 in patients with and without chronic viral hepatitis respectively. In patients with chronic viral hepatitis, ultrasound, dichotomized controlled attenuation parameter and body mass index showed performance of 58.2%, 82.3% and 46.7%, respectively, whereas in patients without chronic viral hepatitis, the performance was 86.4%, 68.6% and 48.6% respectively.

CONCLUSIONS

In patients with chronic viral hepatitis and advanced liver fibrosis, controlled attenuation parameter performs better than ultrasound for assessing liver steatosis, whereas in patients without viral hepatitis and with nonsignificant liver disease ultrasound shows the best performance.

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.

Body-mass index is associated with fibrosis regression during long-term nucleoside analogue therapy in chronic hepatitis B

BACKGROUND

Factors influencing changes in liver stiffness measurements during long-term nucleoside analogue therapy for chronic hepatitis B (CHB) have not been thoroughly investigated.

AIM

To identify determinants of on-treatment fibrosis regression in CHB.

METHODS

We performed follow-up liver stiffness and controlled attenuation parameter measurements on nucleoside analogue-treated CHB patients with severe liver fibrosis, according to EASL-ALEH criteria, diagnosed by transient elastography in 2006-2008. Anthropometric measurements and different metabolic parameters were recorded.

RESULTS

Among 257 patients with severe liver fibrosis by initial transient elastography, 123 (47.9%) were recruited for reassessment. Median treatment duration was 87.5 (interquartile range 75.3-102.2) months; 97.5% had undetectable HBV DNA. There was a significant reduction in median liver stiffness from 14.6 to 8.3 kPa (P < 0.001). A total of 29.3% had fibrosis regression, with lower rates of 17.9%, 14.9% and 11.5% noted in patients with body-mass index (BMI) ≥25 kg/m² , metabolic syndrome and diabetes, respectively. Absence of BMI ≥25 kg/m² , diabetes and metabolic syndrome, when compared with presence of any one of these three factors, was associated with increased fibrosis regression (43.1% vs. 16.9%, P = 0.001). Multivariate analysis found a lower BMI to be the only factor independently associated with fibrosis regression (P = 0.034, odds ratio 0.68, 95% CI 0.48-0.97). No association was noted between controlled attenuation parameter measurements and fibrosis regression (P > 0.05).

CONCLUSION

An increased BMI hindered fibrosis regression in patients with chronic hepatitis B during nucleoside analogue treatment, suggesting that control of metabolic risk factors, in addition to virologic suppression via antiviral therapy, might be needed to halt the fibrogenic process in chronic hepatitis B.

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.

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.

The Relationship between Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease Measured by Controlled Attenuation Parameter

PURPOSE

The severity of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes mellitus (T2DM) population compared with that in normal glucose tolerance (NGT) individuals has not yet been quantitatively assessed. We investigated the prevalence and the severity of NAFLD in a T2DM population using controlled attenuation parameter (CAP).

MATERIALS AND METHODS

Subjects who underwent testing for biomarkers related to T2DM and CAP using Fibroscan® during a regular health check-up were enrolled. CAP values of 250 dB/m and 300 dB/m were selected as the cutoffs for the presence of NAFLD and for moderate to severe NAFLD, respectively. Biomarkers related to T2DM included fasting glucose/insulin, fasting C-peptide, hemoglobin A1c (HbA1c), glycoalbumin, and homeostasis model assessment of insulin resistance of insulin resistance (HOMA-IR).

RESULTS

Among 340 study participants (T2DM, n=66; pre-diabetes, n=202; NGT, n=72), the proportion of subjects with NAFLD increased according to the glucose tolerance status (31.9% in NGT; 47.0% in pre-diabetes; 57.6% in T2DM). The median CAP value was significantly higher in subjects with T2DM (265 dB/m) than in those with pre-diabetes (245 dB/m) or NGT (231 dB/m) (all p<0.05). Logistic regression analysis showed that subjects with moderate to severe NAFLD had a 2.8-fold (odds ratio) higher risk of having T2DM than those without NAFLD (p=0.02; 95% confidence interval, 1.21-6.64), and positive correlations between the CAP value and HOMA-IR (ρ0.407) or fasting C-peptide (ρ0.402) were demonstrated.

CONCLUSION

Subjects with T2DM had a higher prevalence of severe NAFLD than those with NGT. Increased hepatic steatosis was significantly associated with the presence of T2DM, and insulin resistance induced by hepatic fat may be an important mechanistic connection.

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

BACKGROUND/AIMS

The accuracy of noninvasive markers to discriminate nonalcoholic steatohepatitis (NASH) is unsatisfactory. We investigated whether transient elastography (TE) could discriminate patients with NASH from those with nonalcoholic fatty liver disease (NAFLD).

METHODS

The patients suspected of NAFLD who underwent liver biopsy and concomitant TE were recruited from five tertiary centers between November 2011 and December 2013.

RESULTS

The study population (n = 183) exhibited a mean age of 40.6 years and male predominance (n = 111, 60.7%). Of the study participants, 89 (48.6%) had non-NASH and 94 (51.4%) had NASH. The controlled attenuation parameter (CAP) and liver stiffness (LS) were significantly correlated with the degrees of steatosis (r = 0.656, P<0.001) and fibrosis (r = 0.714, P<0.001), respectively. The optimal cut-off values for steatosis were 247 dB/m for S1, 280 dB/m for S2, and 300 dB/m for S3. Based on the independent predictors derived from multivariate analysis [P = 0.044, odds ratio (OR) 4.133, 95% confidence interval (CI) 1.037-16.470 for CAP>250 dB/m; P = 0.013, OR 3.399, 95% CI 1.295-8.291 for LS>7.0 kPa; and P<0.001, OR 7.557, 95% CI 2.997-19.059 for Alanine aminotransferase>60 IU/L], we developed a novel CLA model for discriminating patients with NASH. The CLA model showed good discriminatory capability, with an area under the receiver operating characteristic curve (AUROC) of 0.812 (95% CI 0.724-0.880). To assess discriminatory power, the AUROCs, as determined by the bootstrap method, remained largely unchanged between iterations, with an average value of 0.833 (95% CI 0.740-0.893).

CONCLUSION

This novel TE-based CLA model showed acceptable accuracy in discriminating NASH from simple steatosis. However, further studies are required for external validation.

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.

Clinical applications, limitations and future role of transient elastography in the management of liver disease

Transient elastography (TE) is a reliable tool for the non-invasive assessment of liver fibrosis in routine clinical practice. TE is currently approved for use in Europe, Asia and the United States. The widespread adoption of this technology is certain to increase the use of TE worldwide. Although TE has been well validated in chronic viral hepatitis, its clinical role in other liver diseases remains less clear. The advent of new treatment for chronic hepatitis C and emerging prevalence of non-alcoholic steatohepatitis raises new questions on the role of TE in current clinical practice. This review aims to examine the clinical applications, limitations and future role of TE in current clinical practice in light of the changing epidemiology of liver diseases and new clinical management paradigms. In current clinical practice, TE is the most accurate non-invasive method for diagnosis of liver cirrhosis. TE is useful to rule out fibrosis and cirrhosis but does not have sufficient accuracy to discern between various stages of fibrosis. The clinical role of TE has evolved from cross-sectional point-in-time assessment of fibrosis and cirrhosis to the more relevant role of prediction of vital clinical end-points. This provides clinicians with the ability to modify treatment strategies based on the information provided by TE. TE has evolved over the past decade to become an essential tool to assist the clinician in the management of chronic liver disease.

Predicting Hepatic Steatosis in Living Liver Donors via Noninvasive Methods

Hepatic steatosis assessment is of paramount importance for living liver donor selection because significant hepatic steatosis can affect the postoperative outcome of recipients and the safety of the donor. The validity of various noninvasive imaging methods to assess hepatic steatosis remains controversial. The purpose of our study is to investigate the association between noninvasive imaging methods and pathology to detect steatosis in living liver donors and to propose a prediction model for hepatic steatosis. Liver stiffness measurements (LSMs) and controlled attenuation parameter values in vibration controlled transient elastography, ultrasonography, computed tomography (CT), and magnetic resonance imaging were used as pretransplant screening methods to evaluate living liver donors between 2012 and 2014. Only 1 pathologist assessed tissue sample for hepatic steatosis. The median age of the 79 living donors (53 men and 26 women) was 32 years (16-68 years). The CT liver-spleen attenuation (L-S) difference and the controlled attenuation parameter values were well correlated with the level of hepatic steatosis on liver pathology. Multivariate analysis showed that liver stiffness measurement (LSM) (β = 0.903; 95% CI, 0.105-1.702; P = 0.027) and the CT L to S attenuation difference (β = -3.322; 95% CI, -0.502 to -0.142; P = 0.001) were closely associated with hepatic steatosis. We generated the following equation to predict total hepatic steatosis: Hepatic steatosis = 0.903 × LSM - 0.322 × CT L to S attenuation difference (AUC = 86.6% and P = 0.001). The values predicted by the equation correlated well with the presence of hepatic steatosis (r = 0.509 and P < 0.001). The combination of nonenhanced CT L to S attenuation difference and transient elastography using vibration controlled transient elastography provides sufficient information to predict hepatic steatosis in living liver donor candidates.

Noninvasive Prediction of Erosive Esophagitis Using a Controlled Attenuation Parameter (CAP)-Based Risk Estimation Model

BACKGROUND

Erosive esophagitis and fatty liver share obesity and visceral fat as common critical pathogenesis. However, the relationship between the amount of hepatic fat and the severity of erosive esophagitis was not well investigated, and there is no risk estimation model for erosive esophagitis.

AIM

To evaluate the relationship between the amount of hepatic fat and the severity of erosive esophagitis and then develop a risk estimation model for erosive esophagitis.

METHODS

We enrolled 1045 consecutive participants (training cohort, n = 705; validation cohort, n = 340) who underwent esophagogastroduodenoscopy and CAP. The relationship between severity of fatty liver and erosive esophagitis was investigated, and independent predictors for erosive esophagitis that have been investigated through logistic regression analyses were used as components for establishing a risk estimation model.

RESULTS

The prevalence of erosive gastritis was 10.7 %, and the severity of erosive esophagitis was positively correlated with the degree of hepatic fatty accumulation (P < 0.05). A CAP-based risk estimation model for erosive esophagitis using CAP, Body mass index, and significant alcohol Drinking as constituent variables was established and was dubbed the CBD score (AUROC = 0.819, range 0-11). The high-risk group (CBD score ≥3) showed significantly higher risk of having erosive esophagitis than the low-risk group (CBD score <3) (24.1 vs. 2.7 %, respectively; P < 0.001). The diagnostic accuracy of CBD score was maintained in the validation cohort (AUROC = 0.848).

CONCLUSION

The severity of erosive esophagitis was positively correlated with the degree of hepatic fatty accumulation, and the CBD score might be a simple CAP-based risk model for predicting erosive esophagitis.

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.

Hepatic fibrosis assessed using transient elastography independently associated with coronary artery calcification

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) has a close relationship with coronary atherosclerosis. We investigated the association between coronary atherosclerosis and liver fibrosis, represented as coronary artery calcification (CAC) score, and live stiffness (LS) value assessed using transient elastography (TE), respectively, in patients with NAFLD.

METHODS

Between January 2013 and March 2014, a total of 285 asymptomatic subjects without chronic liver and ischemic heart diseases who underwent comprehensive medical health check-up were recruited. NAFLD was defined as controlled attenuation parameter (CAP) ≥ 250 dB/m on TE.

RESULTS

The median age of the study population (men 161 and women 124) was 56 (interquartile [IQR], 50-63) years. Of these, 142 (49.8%) subjects had NAFLD. Among subjects with NAFLD, CAC score was independently correlated with the male gender (β = 0.230; P = 0.010), elevated erythrocyte sedimentation rate (β = 0.220; P = 0.019), reduced estimated glomerular filtration rate (β=-0.220; P = 0.004), increased left ventricular mass index (β = 0.226; P = 0.027), and higher LS values (β = 0.274; P < 0.001). In addition, alanine aminotransferase level (β = 0.214, P = 0.012) and CAC score (β = 0.311; P = 0.001) are the only independent factors associated with LS values in subjects with NAFLD.

CONCLUSIONS

Higher CAC score was independently correlated with LS values in subjects with NAFLD. However, it should be further investigated whether TE can be incorporated into a screening tool to identify the high-risk population for coronary artery disease.

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.

Use of a Diabetes Self-Assessment Score to Predict Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are strongly associated with obesity, insulin resistance, and type 2 diabetes. We recently developed and validated a self-assessment score in the Korean population to identify people at high risk for diabetes. The objective of this study was to evaluate whether the self-assessment risk score for diabetes can also be used to screen for the presence of NAFLD or NASH.The study population included 15,676 subjects (8313 men and 7363 women) over 20 years old who visited the National Health Insurance Service Ilsan Hospital in Korea between 2008 and 2010. Anthropometric, clinical, and laboratory data were analyzed during regular health checkups. Fatty liver disease was diagnosed using ultrasound, discrimination capability was assessed based on the area under the receiver operating characteristic curve (AUC), and evaluation measures, including sensitivity and specificity, were calculated. Multiple logistic analyses were also performed.We calculated a self-assessed risk score for diabetes (range: 0-11), and a cutoff of ≥5 identified 60% (50%) of men (women) at high risk for NAFLD, reflecting a sensitivity of 79% (85%), a specificity of 60% (66%), a positive predictive value (PPV) of 68% (51%), and a negative predictive value (NPV) of 73% (91%), with an AUC of 0.75 (0.82) for men (women). A cutoff point of ≥6 identified 43% (31%) of men (women) at high risk for NASH, reflecting a sensitivity of 80% (86%), a specificity of 64% (75%), a PPV of 30% (28%), and a NPV of 94% (98%), with an AUC of 0.77 (0.86) for men (women). The odds ratios that a 1-point increase in the diabetes risk scores would be associated with an increased risk for NAFLD and NASH were 1.20 [95% confidence interval (CI): 1.16-1.25] and 1.57 (95% CI: 1.49-1.65), respectively, in men, and 1.28 (95% CI: 1.21-1.34) and 1.89 (95% CI: 1.73-2.07), respectively, in women.The present study indicates that our self-assessment risk score for diabetes could be an effective primary screening tool for the presence of NAFLD or NASH.

Usefulness of liver test and controlled attenuation parameter in detection of nonalcoholic fatty liver disease in patients with chronic renal failure and coronary heart disease

BACKGROUND

In recent years, nonalcoholic fatty liver disease (NAFLD) was recognized as an important factor in chronic kidney disease (CKD) pathogenesis. The concentrations of serum aminotransferases in both chronic dialysis and chronic renal failure (CRF) patients most commonly fall within the lower end of the range of normal values. The aim of the present study was to investigate the usefulness of four liver tests and four biological scores in detection of NAFLD in comparison with transient elastography (TE) findings in different groups of patients.

METHODS

The study was cross-sectional analysis collected data from a single tertiary care center. Of 202 patents there were 52 patients with CKD, 50 patients with end-stage renal disease (ESRD) treated with haemodialysis (HD), 50 renal transplant recipients (RTRs) and 50 patients with proven coronary heart disease (CHD). Fifty sex- and age-matched individuals without NAFLD and with normal liver and kidney function tests served as controls. With the help of TE (FibroScan®, Echosense SA, Paris, France), liver stiffness was selected as the parameter to quantify liver fibrosis and Controlled Attenuation Parameter (CAP) was used to detect and quantify liver steatosis.

RESULTS

According to the CAP findings 76.9 %CKD patients, 82 %HD patients, 74 %RTRs and 69.1 % CHD patients had CAP > 238 dB.m(-1) and thus by definition NAFLD. We have found that ALT, AST and GGT levels were positively correlated with CAP values while ALT and AST showed positive correlation with liver stiffness acquired with TE only in CHD patients. According to TE findings APRI (AUC 0.796) and FIB-4 (AUC 0.790) scores were correlated with the presence of fibrosis, while HIS score was correlated with the presence of steatosis (AUC 0.867) only in CHD patients.

CONCLUSION

Liver tests and biological scores are not useful for NAFLD detection in CRF patients. TE with CAP provides the opportunity of noninvasive screening for NAFLD as well as liver fibrosis in patients with CRF.

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.

Correlation of the controlled attenuation parameter with indices of liver steatosis in overweight or obese individuals: a pilot study

OBJECTIVE

The aim of this study was to assess the clinical relevance of the controlled attenuation parameter (CAP) by analyzing the correlations between CAP and indirect indices of liver steatosis in obese or overweight individuals.

METHODS

Consecutive participants were prospectively enrolled. BMI, waist circumference, hepatic steatosis index, fatty liver index, percent fat mass and regional fat masses as assessed by dual-energy X-ray absorptiometry (DXA), fat signal fraction as assessed by MRI, and CAP were obtained. Pearson's r coefficient was used to test the correlation between two study variables.

RESULTS

A total of 88 individuals were studied. They included 31 men [age, 50.4 years (12.9 years); BMI, 30.7 kg/m (4.8 kg/m)] and 57 women [age, 49.0 years (12.6 years); BMI, 31.4 kg/m (5.6 kg/m)]. DXA, anthropometric parameters, and fatty liver index were moderately correlated with CAP in men. In women, there was a moderate correlation of CAP with the hepatic steatosis index and anthropometric parameters and only a slight or fair correlation of CAP with DXA parameters. CAP and fat signal fraction showed a good correlation (r=0.65 in men, P=0.002; r=0.68 in women, P=0.0009).

CONCLUSION

Measurement of CAP is a reliable method for noninvasive assessment of liver steatosis, showing a correlation with other indirect markers of central obesity and a good correlation with MRI results.

Factors associated with significant liver fibrosis assessed using transient elastography in general population

AIM

To investigate the prevalence of significant liver fibrosis assessed using transient elastography (TE) and its predictors in asymptomatic general population.

METHODS

A total of 159 subjects without chronic viral hepatitis who underwent comprehensive medical health check-up between January 2012 and July 2012 were prospectively recruited. Significant liver fibrosis was defined as liver stiffness value>7.0 kPa.

RESULTS

The mean age and body mass index (BMI) of the study population (men 54.7%) was 56.0 years and 24.3 kg/m2. Among the study subjects, 11 (6.9%) showed significant liver fibrosis. On univariate analysis, BMI, alanine aminotransferase (ALT), homeostasis model assessment of insulin resistance, carotid intimal media thickness (IMT), number of calcified plaques on carotid ultrasound, and visceral fat area on computed tomography were significantly higher in subjects with significant liver fibrosis than in those without (all P<0.05). However, on multivariate analysis, BMI [odds ratio (OR)=.487; P=0.045], ALT (OR=1.078; P=0.014), carotid IMT (OR=3.244; P=0.027), and the number of calcified carotid plaques (OR=1.787; P=0.031) were independent predictors of significant liver fibrosis.

CONCLUSION

The prevalence of significant liver fibrosis assessed using TE was 6.9% in apparently healthy subjects. High BMI, high ALT, thicker carotid IMT, and higher numbers of calcified carotid plaques were independently associated with the presence of significant liver fibrosis.

An overview of effective therapies and recent advances in biomarkers for chronic liver diseases and associated liver cancer

Chronic liver diseases (CLDs) such as hepatitis, alcoholic liver disease, nonalcoholic fatty liver, and their downstream effect cancer affect more than a billion of people around the world both symptomatically and asymptomatically. The major limitation for early detection and suitable medical management of CLDs and liver cancer is either the absent of symptoms or their similar manifestations as other diseases. This detection impediment has led to a steady increase in the number of people suffering from CLDs with an ultimate outcome of liver failure and undergoing transplantation. A better understanding of CLD pathogenesis has helped us to develop novel therapies for patients who are at greatest risk for CLD progression to the most serious disease cancer. With the discovery of aberrant molecular pathways in CLDs, it is now possible to delineate a road map for selecting targeted therapies for CLDs. Technological advances in imaging as well as the availability of several stable, sensitive, early, noninvasive biomarkers for distinguishing different stages of CLDs and cancer have greatly facilitated both drug target identification and real-time monitoring of response to therapy. Biomarkers are the most useful in clinical practice for liver diseases like hepatocellular carcinoma (HCC), which is associated with secretion of various tumor-related proteins or nucleotides in peripheral circulation. The need for the identification of CLD biomarkers remains high. This article reviews the etiologies of CLDs, the results of recent clinical trials of treatments for CLDs, and development of noninvasive methodologies for detecting CLDs and monitoring their progression toward HCC.

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.

Non-invasive diagnosis of alcoholic liver disease

Alcoholic liver disease (ALD) is the most common liver disease in the Western world. For many reasons, it is underestimated and underdiagnosed. An early diagnosis is absolutely essential since it (1) helps to identify patients at genetic risk for ALD; (2) can trigger efficient abstinence namely in non-addicted patients; and (3) initiate screening programs to prevent life-threatening complications such as bleeding from varices, spontaneous bacterial peritonitis or hepatocellular cancer. The two major end points of ALD are alcoholic liver cirrhosis and the rare and clinically-defined alcoholic hepatitis (AH). The prediction and early diagnosis of both entities is still insufficiently solved and usually relies on a combination of laboratory, clinical and imaging findings. It is not widely conceived that conventional screening tools for ALD such as ultrasound imaging or routine laboratory testing can easily overlook ca. 40% of manifest alcoholic liver cirrhosis. Non-invasive methods such as transient elastography (Fibroscan), acoustic radiation force impulse imaging or shear wave elastography have significantly improved the early diagnosis of alcoholic cirrhosis. Present algorithms allow either the exclusion or the exact definition of advanced fibrosis stages in ca. 95% of patients. The correct interpretation of liver stiffness requires a timely abdominal ultrasound and actual transaminase levels. Other non-invasive methods such as controlled attenuation parameter, serum levels of M30 or M65, susceptometry or breath tests are under current evaluation to assess the degree of steatosis, apoptosis and iron overload in these patients. Liver biopsy still remains an important option to rule out comorbidities and to confirm the prognosis namely for patients with AH.

Interobserver reproducibility of the controlled attenuation parameter (CAP) for quantifying liver steatosis

PURPOSE

This study was conducted to prospectively investigate the interobserver reproducibility of controlled attenuation parameter (CAP) measurements and the relationship among the CAP and body mass index (BMI), gender and age.

METHODS

Consecutive subjects were studied using the M+ probe of the FibroScan device (Echosens, Paris, France). Measurements were performed by two raters (rater1 and rater2). Interobserver agreement was assessed by using the concordance correlation coefficient (CCC). The Pearson r coefficient was used to test correlation between two study variables, and linear regression was used for the multivariate model.

RESULTS

Three hundred fifty-one subjects (227 males and 124 females) were prospectively studied. The CCC was 0.82 (95 % CI 0.78-0.85) overall, 0.80 (95 % CI 0.75-0.85) for BMI <25 kg/m(2), 0.76 (95 % CI 0.69-0.84) for BMI 25-29 kg/m(2) and 0.65 (95 % CI 0.41-0.88) for BMI ≥30 kg/m(2). The CCC was 0.44 (95 % CI 0.31-0.56) for CAP values ≤240 dB/m and 0.72 (95 % CI 0.65-0.79) for CAP values >240 dB/m. In univariate analysis, age and BMI by gender were correlated with the CAP. Multiple regression analysis confirmed the relationship of the CAP with age and BMI, but not with gender.

CONCLUSIONS

The results of this study show that the interreader agreement in CAP measurement is good. In healthy volunteers, the CAP is strongly correlated with age and BMI.

Controlled attenuation parameter for the detection and quantification of hepatic steatosis in nonalcoholic fatty liver disease

BACKGROUND AND AIM

Controlled attenuation parameter (CAP) has been suggested as a noninvasive method for detection and quantification of hepatic steatosis. We aim to study the diagnostic performance of CAP in nonalcoholic fatty liver disease (NAFLD) patients.

METHODS

Transient elastography was performed in consecutive NAFLD patients undergoing liver biopsy and non-NAFLD controls. The accuracy of CAP for the detection and quantification of hepatic steatosis was assessed based on histological findings according to the Nonalcoholic Steatohepatitis Clinical Research Network Scoring System.

RESULTS

Data for 101 NAFLD patients (mean age 50.3 ± 11.3 years old, 51.5% male) and 60 non-NAFLD controls were analyzed. CAP was associated with steatosis grade (odds ratio [OR] = 29.16, P < 0.001), body mass index (BMI; OR = 4.34, P < 0.001) and serum triglyceride (OR = 13.59, P = 0.037) on multivariate analysis. The median CAP for steatosis grades S0, S1, S2, and S3 were 184 dB/m, 305 dB/m, 320 dB/m, and 324 dB/m, respectively. The areas under receiver operating characteristics curves (AUROC) for estimation of steatosis grades ≥ S1, S2, and S3 were 0.97, 0.86, and 0.75, respectively. The optimal CAP cutoffs for estimation of steatosis grades ≥ S1, S2, and S3 were 263 dB/m, 281 dB/m, and 283 dB/m, respectively. Among non-obese patients, the AUROC for estimation of steatosis grades ≥ S1 and S2 were 0.99 and 0.99, respectively. Among obese patients, the AUROC for estimation of steatosis grades ≥ S1, S2, and S3 were 0.92, 0.64, and 0.58, respectively.

CONCLUSIONS

CAP is excellent for the detection of significant hepatic steatosis. However, its accuracy is impaired by an increased BMI, and it is less accurate to distinguish between the different grades of hepatic steatosis.

Factors affecting the accuracy of controlled attenuation parameter (CAP) in assessing hepatic steatosis in patients with chronic liver disease

BACKGROUND & AIMS

Controlled attenuation parameter (CAP) can measure hepatic steatosis. However, factors affecting its accuracy have not been described yet. This study investigated predictors of discordance between liver biopsy (LB) and CAP.

METHODS

A total of 161 consecutive patients with chronic liver disease who underwent LB and CAP were enrolled prospectively. Histological steatosis was graded as S0 (<5%), S1 (5-33%), S2 (34-66%), and S3 (>66% of hepatocytes). Cutoff CAP values were calculated from our cohort (250, 301, and 325 dB/m for ≥ S1, ≥ S2, and S3). Discordance was defined as a discrepancy of at least two steatosis stages between LB and CAP.

RESULTS

The median age (102 males and 59 females) was 49 years. Repartition of histological steatosis was as follows; S0 26.1% (n = 42), S1 49.7% (n = 80), S2 20.5% (n = 33), and S3 3.7% (n = 6). In multivariate linear regression analysis, CAP value was independently associated with steatosis grade along with body mass index (BMI) and interquartile range/median of CAP value (IQR/MCAP) (all P<0.05). Discordance was identified in 13 (8.1%) patients. In multivariate analysis, histological S3 (odd ratio [OR], 9.573; 95% confidence interval [CI], 1.207-75.931; P = 0.033) and CAP value (OR, 1.020; 95% CI, 1.006-1.034; P = 0.006) were significantly associated with discordance, when adjusting for BMI, IQR/MCAP, and necroinflammation, reflected by histological activity or ALT level.

CONCLUSIONS

Patients with high grade steatosis or high CAP values have a higher risk of discordance between LB and CAP. Further studies are needed to improve the accuracy of CAP interpretation, especially in patients with higher CAP values.

Detection of hepatic steatosis using the controlled attenuation parameter: a comparative study with liver biopsy

OBJECTIVE

Measurements of controlled attenuation parameter (CAP) with transient elastography (FibroScan®; EcoSens SA, Paris, France) may provide an accurate noninvasive assessment of hepatic steatosis. Herein, we prospectively determined the accuracy of liver fat quantification with CAP values in patients with chronic liver diseases and compare the results with those of histological assessment of steatosis as reference standard.

MATERIALS AND METHODS

We enrolled 50 Turkish patients with various forms of chronic liver diseases. All patients underwent both CAP assessment and ultrasonography-guided liver biopsy.

RESULTS

On liver biopsy, 16 (32%) patients had S0, 12 (24%) had S1, 9 (18%) had S2, and 13 (26%) had S3. The CAP values increased significantly (p<0.001) for each steatosis stage on liver biopsy: S0, 222 dB/m; S1, 250 dB/m; S2, 270 dB/m; and S3, 318 dB/m. A cutoff value of 257 dB/m could distinguish significant steatosis (S2-S3) from S0 (Sn 89%, Sp 83%, positive likelihood ratio 5.33, negative likelihood ratio 0.13, AUROC=0.93). Multivariable analysis indicated that neither liver fibrosis (p=0.58) nor disease etiology (p=0.96) had a significant impact on the association between CAP and the stage of steatosis.

CONCLUSION

The determination of CAP using transient elastography can represent an important step forward toward the goal of an "imaging liver biopsy".

Non-invasive assessment of hepatic steatosis in patients with NAFLD using controlled attenuation parameter and 1H-MR spectroscopy

Introduction

Non-invasive assessment of steatosis and fibrosis is of growing relevance in non-alcoholic fatty liver disease (NAFLD). ¹H-Magnetic resonance spectroscopy (¹H-MRS) and the ultrasound-based controlled attenuation parameter (CAP) correlate with biopsy proven steatosis, but have not been correlated with each other so far. We therefore performed a head-to-head comparison between both methods.

Methods

Fifty patients with biopsy-proven NAFLD and 15 healthy volunteers were evaluated with ¹H-MRS and transient elastography (TE) including CAP. Steatosis was defined according to the percentage of affected hepatocytes: S1 5-33%, S2 34–66%, S3 ≥67%.

Results

Steatosis grade in patients with NAFLD was S1 36%, S2 40% and S3 24%. CAP and ¹H-MRS significantly correlated with histopathology and showed comparable accuracy for the detection of hepatic steatosis: areas under the receiver-operating characteristics curves were 0.93 vs. 0.88 for steatosis ≥S1 and 0.94 vs. 0.88 for ≥S2, respectively. Boot-strapping analysis revealed a CAP cut-off of 300 dB/m for detection of S2-3 steatosis, while retaining the lower cut-off of 215 dB/m for the definition of healthy individuals. Direct comparison between CAP and ¹H-MRS revealed only modest correlation (total cohort: r = 0.63 [0.44, 0.76]; NAFLD cases: r = 0.56 [0.32, 0.74]). For detection of F2–4 fibrosis TE had sensitivity and specificity of 100% and 98.1% at a cut-off value of 8.85 kPa.

Conclusion

Our data suggest a comparable diagnostic value of CAP and ¹H-MRS for hepatic steatosis quantification. Combined with the simultaneous TE fibrosis assessment, CAP represents an efficient method for non-invasive characterization of NAFLD. Limited correlation between CAP and ¹H-MRS may be explained by different technical aspects, anthropometry, and presence of advanced liver fibrosis.