Noninvasive detection of hepatic steatosis in patients without ultrasonographic evidence of fatty liver using the controlled attenuation parameter evaluated with transient elastography

Analysis of clinical findings and serum micronutrients in pediatric patients with nonalcoholic fatty liver disease

Aim: Serum micronutrient levels play an important role in liver metabolism. This study examines risk factors and diagnostic methods for patients on follow-up due to nonalcoholic fatty liver disease (NAFLD). NAFLD and the control groups were compared for clinical findings, serum ferritin, B12, and vitamin D levels, and their relationship with NAFLD was examined. Material and Method: Included in the study were 60 NAFLD patients and 66 other children that formed the control group. The two groups were compared in serum lipid profile, aminotransferase, insulin, glucose, and HOMA-IR. Ultrasonography (USG) and Shear wave elastography (SWE) were performed on all patients. Both groups were then analyzed in terms of serum ferritin, B12, and vitamin D levels. Results: NAFLD and control groups were compared in terms of USG and SWE results. 35% (n=21)of the patients in the NAFLD group had grade 1, 55% (n=33) had grade 2 and 10% (n=6) had grade 3 adiposity. HOMA-IR and insulin levels were higher in the NAFLD group (p=0.02; p=0.001). While the serum ferritin level of the patients in the NAFLD group was higher than the control group (p=0.001); the B12 level was lower (p=0.006). In terms of vitamin D, there was no difference (p=0.368). Conclusion: It is essential to identify risk factors in children on follow-up due to NAFLD. USG and liver function tests remain the first option in the diagnosis and screening of NAFLD in children. Serum ferritin, B12, and vitamin D levels of children on follow-up due to NAFLD should be analyzed in consideration of liver fattening.

Epidemiology, natural history, and diagnosis of metabolic dysfunction-associated fatty liver disease: a comparative review with nonalcoholic fatty liver disease

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) is the most common chronic liver disease worldwide - with an estimated global prevalence of 37%. Different from nonalcoholic fatty liver disease (NAFLD), which is an exclusion diagnosis, MAFLD is defined by a set of positive criteria. This recent change in terminology is challenging because MAFLD and NAFLD denote two similar, albeit not identical, clinical populations. When the diagnostic criteria for MAFLD are applied, liver histology appears more severe and clinical outcomes are less favorable. However, the clinical management of MAFLD and NAFLD remains similar. While liver biopsy is still the reference standard for achieving a final diagnosis, noninvasive imaging- or biomarker-based diagnostic modalities are currently gaining momentum. However, liver biopsy should be recommended when diagnostic challenges exist. In this review, we compared the epidemiology, natural history, and diagnosis of MAFLD with respect to the traditional NAFLD definition.

Non-Laboratory-Based Simple Screening Model for Nonalcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Developed Using Multi-Center Cohorts

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic liver disease worldwide. Type 2 diabetes mellitus (T2DM) is a risk factor that accelerates NAFLD progression, leading to fibrosis and cirrhosis. Thus, here we aimed to develop a simple model to predict the presence of NAFLD based on clinical parameters of patients with T2DM.

METHODS

A total of 698 patients with T2DM who visited five medical centers were included. NAFLD was evaluated using transient elastography. Univariate logistic regression analyses were performed to identify potential contributors to NAFLD, followed by multivariable logistic regression analyses to create the final prediction model for NAFLD.

RESULTS

Two NAFLD prediction models were developed, with and without serum biomarker use. The non-laboratory model comprised six variables: age, sex, waist circumference, body mass index (BMI), dyslipidemia, and smoking status. For a cutoff value of ≥60, the prediction accuracy was 0.780 (95% confidence interval [CI], 0.743 to 0.817). The second comprehensive model showed an improved discrimination ability of up to 0.815 (95% CI, 0.782 to 0.847) and comprised seven variables: age, sex, waist circumference, BMI, glycated hemoglobin, triglyceride, and alanine aminotransferase to aspartate aminotransferase ratio. Our non-laboratory model showed non-inferiority in the prediction of NAFLD versus previously established models, including serum parameters.

CONCLUSION

The new models are simple and user-friendly screening methods that can identify individuals with T2DM who are at high-risk for NAFLD. Additional studies are warranted to validate these new models as useful predictive tools for NAFLD in clinical practice.

Association of circulating adipsin with nonalcoholic fatty liver disease in obese adults: a cross-sectional study

BACKGROUND

As a secreted adipokine, adipsin has been recently shown to play a pivotal role in metabolic disorders. However, information regarding the association of circulating adipsin with non-alcoholic fatty liver disease (NAFLD) in humans is scant.

METHODS

We recruited 1163 obese adult subjects with waist circumference at least 90 cm in men and 80 cm in women from the community. Circulating adipsin levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Circulating adipsin levels of NAFLD subjects was decreased compared to those in non-NAFLD (p < 0.05). The prevalence of NAFLD with lower levels of serum adipsin was significantly higher than those with higher values (57.6% vs. 50.9%, p < 0.05). Circulating adipsin levels were significantly associated with decreasing levels of fasting glucose and postprandial glucose (both p < 0.001 for interaction) in NAFLD subjects but not in non-NAFLD subjects. The risk of NAFLD was significantly decreased by 21.7% [OR (95% CI): 0.783 (0.679-0.902), p < 0.001], adjusting for age, gender, current smoking, alcohol consumption, physical activity, BMI, systolic BP, fasting glucose, total cholesterol, HDL-c, HOMA-IR, and body fat mass. Importantly, subjects in the lowest quartile of circulating adipsin were 1.88 times more likely to have NAFLD than those in the highest quartile in multivariable logistic regression analyses. However, such associations with circulating adipsin were not noted for metabolic syndrome, abnormal liver enzyme and significant liver fibrosis.

CONCLUSIONS

These results demonstrate that circulating adipsin levels in Chinese obese adults are negatively associated with risk of NAFLD, implying that serum adipsin levels may be a potential protective factor in NAFLD.

Non-alcoholic fatty liver disease: A growing public health problem in Turkey

Non-alcoholic fatty liver disease (NAFLD) is histologically classified as either non-alcoholic fatty liver or non-alcoholic steatohepatitis (NASH). NASH is the progressive subtype of NAFLD. Individuals with NASH are at significant risk of developing hepatic fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related and all-cause mortality. NAFLD is closely associated with obesity, type 2 diabetes mellitus (T2DM), metabolic syndrome, and cardiovascular events. Its prevalence is estimated to be above 30% in Turkey; and recent studies confirm this estimate. According to these studies, the prevalence of NAFLD in Turkey is between 48.3% and 60.1%. Currently, Turkey can be considered a risky region in terms of NAFLD burden as it is the most obese country in Europe with an obesity prevalence of 32.1% according to the 2016 World Health Organization data. Moreover, along with the increasing prevalence of obesity and T2DM in Turkey, the burden of NAFLD is estimated to increase in the upcoming decade. Despite the growing burden, we lack well-designed systemic studies that investigate NAFLD and its marked histological severity. In this review, we present studies on the burden of NAFLD and NASH, the natural history of NAFLD, and its association with other systemic diseases conducted with Turkish populations.

Biglycan and atherosclerosis: Lessons from high cardiovascular risk conditions

Atherosclerosis (ATH) is a chronic, dynamic, evolutive process involving morphological and structural subversion of artery walls, leading to the formation of atherosclerotic plaques. ATH generally initiates during the childhood, occurring as a result of a number of changes in the intima tunica and in the media of arteries. A key event occurring during the pathobiology of ATH is the accumulation of lipoproteins in the sub-intimal spaces mediated by extracellular matrix (ECM) molecules, especially by the chondroitin sulfate/dermatan sulfate (CS/DS) -containing proteoglycans (CS/DSPGs). Among them, the proteoglycan biglycan (BGN) is critically involved in the onset and progression of ATH and evidences show that BGN represents the missing link between the pro-atherogenic status induced by both traditional and non-traditional cardiovascular risk factors and the development and progression of vascular damage. In the light of these findings, the role of BGN in dyslipidemia, hypertension, cigarette smoking, diabetes, chronic kidney disease and inflammatory status is briefly analyzed and discussed in order to shed new light on the underlying mechanisms governing the association between BGN and ATH.

Screening for hepatic fibrosis and steatosis in Turkish patients with type 2 diabetes mellitus: A transient elastography study

BACKGROUND/AIMS

Non-alcoholic fatty liver disease is highly prevalent in patients with type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate the potential usefulness of transient elastography (TE), which is a technique that allows measuring both fibrosis and liver fat content simultaneously, as a screening tool for hepatic involvement in Turkish patients with T2DM.

MATERIALS AND METHODS

We obtained liver stiffness measurements (LSMs, as a measure of fibrosis) and controlled attenuation parameter (CAP, as a marker of steatosis) in 124 (46 males and 78 females; mean body mass index (BMI): 33.2±6.6 kg/m2) Turkish patients with T2DM. The prevalence rates of overweight, obesity, and metabolic syndrome in our sample were 28.2%, 64.5%, and 77.4%, respectively. Probe-specific LSM cut-off values were used to define advanced fibrosis (>F3) and cirrhosis (F4) (M probe: F3=9.6-11.4 kPa, F4 >11.5 kPa and XL probe: F3=9.3-10.9 kPa, F4 >11.0 kPa). Mild, moderate, and severe steatosis were defined as CAP 222-232 dB/m, CAP 233-289 dB/m, and CAP >290 dB/m, respectively.

RESULTS

Advanced fibrosis and cirrhosis were identified in 21 (16.9%) and 10 (8.0%) patients, respectively. TE-defined hepatic steatosis (CAP>222 dB/m) was detected in 117 (94.3%) patients. Mild, moderate, and severe steatosis were identified in 0, 29, and 88 patients, respectively.

CONCLUSION

TE is a useful non-invasive imaging modality to screen for liver involvement in Turkish patients with T2DM. High rates of TE-defined fibrosis and steatosis in our sample reflect the presence of an elevated mean BMI.

Clinical implications of controlled attenuation parameter in a health check-up cohort

BACKGROUND & AIMS

Evaluation of the controlled attenuation parameter (CAP) is a promising noninvasive method for assessing hepatic steatosis. Despite the increasing reliability of the CAP for assessing steatosis in subjects with chronic liver disease, few studies have evaluated the CAP in asymptomatic subjects without overt liver disease. Therefore, we aimed to evaluate the usefulness of the CAP for a health check-up population.

METHODS

We enrolled subjects who underwent abdominal ultrasonography (US), FibroScan (Echosens, France) and blood sampling during medical health check-ups. The CAP was measured using FibroScan, and increased CAP was defined as CAP ≥ 222 dB/m.

RESULTS

A total of 1133 subjects were included; 589 subjects (52.0%) had fatty liver based on US, and 604 subjects (53.3%) had increased CAP. Increased CAP was significantly associated with metabolic abnormalities, including higher body mass index (BMI)[odds ratio (OR) = 1.33;95% confidence interval (CI),1.24-1.43; P < .001], higher alanine aminotransferase (ALT) (OR = 1.02; 95% CI, 1.01-1.04; P = .003), higher insulin (OR = 1.04; 95% CI, 1.00-1.08; P = .037), higher triglyceride (OR = 1.00; 95% CI, 1.00-1.01; P = 0.042) and older age (OR = 1.02; 95% CI, 1.00-1.03; P = .05). Furthermore, a comparison of clinical parameters among three groups (normal vs no fatty liver by US but increased CAP vs fatty liver based on US) revealed that metabolic parameters, including blood pressure, BMI, waist circumference, aspartate aminotransferase (AST), ALT, triglycerides, fasting glucose, uric acid, insulin, homeostasis model assessment-estimated insulin resistance and liver stiffness measurements, gradually increased across the three groups (all P < .001).

CONCLUSIONS

In conclusion, increased CAP could be an early indicator of fatty liver disease with metabolic abnormalities that manifests even before a sonographic fatty change appears.

Using controlled attenuation parameter combined with ultrasound to survey non-alcoholic fatty liver disease in hemodialysis patients: A prospective cohort study

BACKGROUND AND AIMS

Controlled attenuation parameter (CAP) is a non-invasive method for measuring hepatic steatosis (HS). Non-alcoholic fatty liver disease (NAFLD) is closely related to cardiovascular diseases (CVDs). CVDs are the leading cause of morbidity and mortality in hemodialysis patients. The aim of this study was to investigate the prevalence of NAFLD in hemodialysis patients.

METHOD

We prospectively enrolled patients undergoing chronic hemodialysis, as well as patients with normal renal function who served as controls. The control group patients were referred by an endocrinologist to be tested for NAFLD; most of these patients had diabetes, hypertension, or dyslipidemia. We excluded those with excess alcohol intake, use of drugs known to induce HS, chronic viral hepatitis, or CAP failure. CAP ≥ 238 dB/m was used as a cutoff suggesting HS. An increased liver kidney contrast, as defined by ultrasound, was used to make the diagnosis of HS.

RESULTS

Three hundred and forty-three hemodialysis patients and 252 control group patients were enrolled. Among the hemodialysis patients, 192 (56.0%) had CAP- or ultrasound-identified HS compared with 91 (26.5%) who only had ultrasound-identified HS (P<0.001). Among the control group patients, 212 (84.1%) had CAP- or ultrasound-identified HS compared with 180 (71.4%) who only had ultrasound-identified HS (P<0.001).

CONCLUSIONS

The prevalence of NAFLD in the hemodialysis patients was 56%. The number of diagnoses of NAFLD made by using CAP combined with ultrasound was more than 2 times the number made with ultrasound alone in the hemodialysis patients. Therefore, we suggest the use of CAP combined with ultrasound to screen for NAFLD in hemodialysis patients.

Prevalence of hepatic steatosis in apparently healthy medical students: a transient elastography study on the basis of a controlled attenuation parameter

OBJECTIVE

Despite the increasing burden of nonalcoholic fatty liver disease (NAFLD) in modern societies, the optimal screening method to detect hepatic steatosis in the general population remains to be established. Controlled attenuation parameter (CAP) measured with transient elastography (TE) has recently emerged as a reliable imaging tool for the screening and diagnosis of NAFLD. Here, we sought to investigate the prevalence of TE-defined hepatic steatosis in a sample of apparently healthy medical students. We also assessed the relationships between CAP and traditional NAFLD risk factors.

MATERIALS AND METHODS

A total of 112 Turkish medical students (48 women and 64 men, mean age 20.5±1.1 years) underwent TE. On the basis of previous studies, a cut-off value of 238 dB/m for CAP was used for the diagnosis of hepatic steatosis.

RESULTS

On the basis of the selected cut-off for CAP, we identified 26 students (23.2%) with TE-defined NAFLD. Univariate correlation analyses showed that CAP values were significantly associated with BMI (r=0.40, P<0.001), waist circumference (r=0.39, P<0.001), and hip circumference (r=0.34, P<0.001). In multivariable analysis, only BMI retained its independent association with CAP (β=0.36, t=3.4, P<0.001).

CONCLUSION

NAFLD is highly prevalent even in apparently healthy young individuals. CAP assessment with TE may be useful for an early, noninvasive identification of hepatic steatosis.

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.

A Guide to Non-Alcoholic Fatty Liver Disease in Childhood and Adolescence

Non-Alcoholic Fatty Liver Disease (NAFLD) is now the most prevalent form of chronic liver disease, affecting 10%–20% of the general paediatric population. Within the next 10 years it is expected to become the leading cause of liver pathology, liver failure and indication for liver transplantation in childhood and adolescence in the Western world. While our understanding of the pathophysiological mechanisms underlying this disease remains limited, it is thought to be the hepatic manifestation of more widespread metabolic dysfunction and is strongly associated with a number of metabolic risk factors, including insulin resistance, dyslipidaemia, cardiovascular disease and, most significantly, obesity. Despite this, ”paediatric” NAFLD remains under-studied, under-recognised and, potentially, undermanaged. This article will explore and evaluate our current understanding of NAFLD in childhood and adolescence and how it differs from adult NAFLD, in terms of its epidemiology, pathophysiology, natural history, diagnosis and clinical management. Given the current absence of definitive radiological and histopathological diagnostic tests, maintenance of a high clinical suspicion by all members of the multidisciplinary team in primary and specialist care settings remains the most potent of diagnostic tools, enabling early diagnosis and appropriate therapeutic intervention.

PNPLA3 148M Carriers with Inflammatory Bowel Diseases Have Higher Susceptibility to Hepatic Steatosis and Higher Liver Enzymes

BACKGROUND

Inflammatory bowel diseases (IBD) are characterized by chronic relapsing inflammation of the gastrointestinal tract and encompass Crohn's disease and ulcerative colitis. IBD are often associated with extraintestinal manifestations affecting multiple organs including the liver. Increased levels of serum aminotransferases, possibly related to nonalcoholic fatty liver disease, constitute one of the most frequently described IBD-related liver diseases. The PNPLA3 I148M substitution is a major common genetic determinant of hepatic fat content and progression to chronic liver disease. The aim of this study was to investigate whether carriers of PNPLA3 148M allele with IBD have higher risk of liver steatosis and increase in transaminases levels.

METHODS

The PNPLA3 I148M (rs738409) genotype was performed by Taqman assays in 158 individuals from Southern Italy (namely, Catanzaro cohort) and in 207 individuals from Northern Italy (namely, Milan cohort) with a definite diagnosis of IBD. Demographic and clinical data and also alanine transaminase levels were collected for both cohorts. The Catanzaro cohort underwent liver evaluation by sonography and liver stiffness and controlled attenuation parameter measurements by transient elastography.

RESULTS

Here, we show for the first time that carriers of the PNPLA3 148M allele with IBD have a greater risk of hepatic steatosis (odds ratio, 2.9, and confidence interval, 1.1-7.8), higher controlled attenuation parameter values (P = 0.029), and increased circulating alanine transaminase (P = 0.035) in the Catanzaro cohort. We further confirm the higher alanine transaminase levels in the Milan cohort (P < 0.001).

CONCLUSIONS

Our results show that PNPLA3 148M carriers with IBD have higher susceptibility to hepatic steatosis and liver damage.

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.

Measurements of serum procollagen-III peptide and M30 do not improve the diagnostic accuracy of transient elastography for the detection of hepatic fibrosis in patients with nonalcoholic fatty liver disease

BACKGROUND

Transient elastography (TE) has recently emerged as an accurate noninvasive imaging method for the diagnosis of liver fibrosis in nonalcoholic fatty liver disease (NAFLD). Here, we tested whether adding serum measures of serum procollagen-III peptide (PIIIP) and caspase-cleaved cytokeratin 18 fragment (M30) to TE could improve its diagnostic accuracy in patients with biopsy-proven NAFLD.

PATIENTS AND METHODS

TE was performed in 87 patients with NAFLD. Serum PIIIP and M30 levels were determined by enzyme-linked immunosorbent assay. Liver histology was considered the gold standard. The diagnostic accuracies were assessed by measuring the area under the receiver operating curve.

RESULTS

At histopathological examination, 34 patients (39.1%) had significant fibrosis (F2-F4) and 19 patients (21.8%) had advanced fibrosis (F3-F4). Both TE and serum M30 levels were independent predictors of fibrosis, whereas no association was found with PIIIP. No significant differences in terms of sensitivity and specificity for both significant and advanced fibrosis were evident for TE, serum M30, or their combination. Moreover, the area under the receiver operating curves of serum M30 combined with TE did not differ significantly from those of either test alone.

CONCLUSION

Both TE and serum M30 levels are accurate for the noninvasive diagnosis of fibrosis in NAFLD. However, their combination did not improve the overall diagnostic accuracy.

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.

Non-alcoholic fatty liver disease: what the clinician needs to know

Non-alcoholic fatty liver disease (NAFLD) is the most frequent cause of liver disease in the Western world. Furthermore, it is increasing worldwide, paralleling the obesity pandemic. Though highly frequent, only about one fifth of affected subjects are at risk of developing the progressive form of the disease, non-alcoholic steatohepatitis with fibrosis. Even in the latter, liver disease is slowly progressive, though, since it is so prevalent, it is already the third cause of liver transplantation in the United States, and it is predicted to get to the top of the ranking in few years. Of relevance, fatty liver is also associated with increased overall mortality and particularly increased cardiovascular mortality. The literature and amount of published papers on NAFLD is increasing as fast as its prevalence, which makes it difficult to keep updated in this topic. This review aims to summarize the latest knowledge on NAFLD, in order to help clinicians understanding its pathogenesis and advances on diagnosis and treatment.

Controlled attenuation parameter for the detection of steatosis severity in chronic liver disease: a meta-analysis of diagnostic accuracy

BACKGROUND AND AIM

Controlled attenuation parameter (CAP) is a novel ultrasound-based elastography method for detection of steatosis severity. This meta-analysis aimed to assess the performance of CAP.

METHODS

PubMed, the Cochrane Library, and the Web of Knowledge were searched to find studies, published in English, relating to accuracy evaluations of CAP for detecting stage 1 (S1), stage 2 (S2), or stage 3 (S3) hepatic steatosis which was diagnosed by liver biopsy. Sensitivities, specificities, and hierarchical summary receiver operating characteristic (HSROC) curves were used to examine CAP performance. The clinical utility of CAP was also evaluated.

RESULTS

Nine studies, with 11 cohorts were analyzed. The summary sensitivities and specificities values were 0.78 (95% confidence interval [CI], 0.69-0.84) and 0.79 (95% CI, 0.68-0.86) for ≥ S1, 0.85 (95% CI, 0.74-0.92) and 0.79 (95% CI, 0.71-0.85) for ≥ S2, and 0.83 (95% CI, 0.76-0.89) and 0.79 (95% CI, 0.68-0.87) for ≥ S3. The HSROCs were 0.85 (95% CI, 0.81-88) for ≥ S1, 0.88 (95% CI, 0.85-0.91) for ≥ S2, and 0.87 (95% CI, 0.84-0.90) for ≥ S3. Following a "positive" measurement (over the threshold value) for ≥ S1, ≥ S2, and ≥ S3, the corresponding post-test probabilities for the presence of steatosis (pretest probability was 50%) were 78%, 80% and 80%, respectively; if the values were below these thresholds ("negative" results), the post-test probabilities were 22%, 16%, and 17%, respectively.

CONCLUSIONS

CAP has good sensitivity and specificity for detecting hepatic steatosis; however, based on a meta-analysis, CAP was limited in their accuracy of steatosis, which precluded widespread use in clinical practice.

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".