Hepatic steatosis, detected by hepatorenal index in ultrasonography, as a predictor of insulin resistance in obese subjects

Ultrasound screening of paediatric non-alcoholic fatty liver disease (NAFLD): A critical literature review

INTRODUCTION

Paediatric NAFLD is an increasing global health concern, which can be effectively managed with early detection. Screening, using accurate, affordable, and accessible tests is recommended, however, there is currently no consensus on the most appropriate tests. Although ultrasound techniques are widely used, their performance against reference tests have not been fully assessed.

METHODS

A literature search of related databases for peer-reviewed original articles published from January 2010-March 2024 was conducted. Appropriate tools were used to systematise and document the search results and selected studies were quality assessed and critically appraised. Extracted data was subjected to thematic analysis and narrative synthesis.

RESULTS

Eighteen articles met the inclusion criteria. B-mode and Quantitative ultrasound techniques were compared against MR spectroscopy, MRI-PDFF and Liver biopsy.

CONCLUSION

Liver echogenicity and Steato-scores were the B-mode methods used. The former was less effective, with a maximum reported sensitivity of 70%. The latter reached up to 100% sensitivity, and >80% specificity. Ultrasound performed better with moderate-severe steatosis. There was not enough evidence to support steatosis grading, possibly due to small sample sizes and lack of established cut-off values. QUS (Quantitative Ultrasound)) methods including Continuous Attenuation Parameter (CAP), Attenuation Coefficient (AC), Ultrasound derived fat fraction (UDFF), Tissue Scatter Imaging (TSI) Hepato-Renal Index (HRI), Heterogeneity Index (HIA), Computer Assisted Ultrasound (CAUS) and Picture Archiving and Communication System (PACS-based Image analysis performed better than B-mode methods. Although QUS demonstrated excellent performance, with sensitivity and specificity of up to 100%, this will require further verification before implementation in practice.

PRACTICE IMPLICATIONS

Ultrasound techniques can effectively be used for paediatric NAFLD screening, especially in higher-risk subjects. The steato-scores method is currently recommendable for this, with excellent potential for the use of QUS, after cut-off values and validation requirements have been addressed.

Liver stiffness, hepatorenal index, and microRNA-130b as predictors for chronic kidney disease in patients with non-alcoholic fatty liver disease

Background and aim

Currently, nonalcoholic liver disease (NAFLD) is the most predominant chronic liver disorder. NAFLD has been linked to hepatic and extrahepatic morbidities. We aimed to investigate the role of acoustic radiation force impulse (ARFI), hepatorenal index (HRI), and serum microRNA-130b as non-invasive predictors for chronic kidney disease (CKD) in NAFLD patients.

Material and methods

In a case–control design, we included 40 NAFLD patients (20 NAFLD with CKD and 20 NAFLD without CKD) and 20 healthy controls. After clinical evaluation, laboratory assessments including liver test profile, renal function test, and quantification of microRNA-130b were done. Liver steatosis and stiffness were evaluated using HRI and ARFI.

Results

HRI and ARFI readings were significantly higher among NAFLD with CKD patients compared to other groups (P < 0.001). The median values of microRNA-130b were 32.1, 27.01, and 25.36 copies/µl in NAFLD with CKD, NAFLD without CKD, and healthy controls, respectively, with significant differences between groups (P < 0.05). ARFI values and HRI were positively correlated with microRNA-130b (P < 0.05). At a cutoff value > 28.13 copies/µl, microRNA-130b could differentiate between “NAFLD with CKD” and “NAFLD without CKD” patients with a sensitivity and specificity of 75% and 70%, respectively (AUC = 71.9%, P = 0.018).

Conclusions

Serum microRNA-130b, HRI, and ARFI are valuable noninvasive markers for the assessment of NAFLD. MicroRNA-130b is suggested as a sensitive biomarker for the prediction of CKD among NAFLD patients with good sensitivity and specificity.

Quantification of Hepatic Steatosis by Ultrasound: Prospective Comparison With MRI Proton Density Fat Fraction as Reference Standard

BACKGROUND. Multiple ultrasound platforms now provide quantitative measures of hepatic steatosis. One such measure is the ultrasound-derived fat fraction (UDFF), which combines attenuation and backscatter quantification. OBJECTIVE. The purpose of this study was to characterize agreement between UDFF and MRI proton-density fat fraction (PDFF) measurements. METHODS. This prospective cross-sectional study enrolled 56 overweight and obese adolescents and adults (age ≥ 16 years) who underwent investigational ultrasound (deep abdominal transducer) and MRI examinations of the liver during a single visit from August 2020 to October 2020. Ultrasound examinations included three UDFF acquisitions of five measurements each (15 measurements total), and an overall median of medians was computed (UDFFoverall). MRI examinations included three PDFF acquisitions with calculation of an overall median PDFF. Spearman rank-order correlation was computed between UDFF and MRI PDFF measurements. Intraclass correlation coefficients and Bland-Altman difference plots were used to assess agreement. ROC curves were used to assess diagnostic performance of UDFF for detecting MRI PDFF of 5.5% or more. RESULTS. Median participant age was 32.5 years (IQR, 24.0-39.0 years); 40 participants were female, and 16 were male. A total of 34 (60.7%) participants had an MRI PDFF of 5.5% or more. UDFFoverall was 10.5% (IQR, 5.0-20.0%); median MRI PDFF was 6.1% (IQR, 3.4-13.7%). UDFFoverall was positively associated with MRI PDFF (ρ, 0.82; p < .001; intraclass correlation coefficient, 0.84 [95% CI, 0.59-0.93]). Mean bias between UDFF and PDFF was 4.0% (95% limits of agreement, -7.9% to 15.9%), with similar bias if summarizing UDFF by the first five measurements (4.4%), first three measurements (4.4%), or first measurement (4.6%). UDFFoverall AUC was 0.90 (95% CI, 0.79-0.96) for MRI PDFF of 5.5% or more; AUC was not significantly different when it was based on the number of UDFF measurements (p = .11-.97 for all pairwise AUC comparisons). UDFFoverall cutoff of more than 5% had sensitivity of 94.1% and specificity of 63.6% for diagnosing MRI PDFF of 5.5% or more. CONCLUSION. Measurements of hepatic steatosis using UDFF show strong agreement with measurements by MRI PDFF. A UDFFoverall cutoff of more than 5% provides high AUC and sensitivity, albeit low specificity, for detection of MRI PDFF of 5.5% or more. CLINICAL IMPACT. UDFF may have a clinical role in detection of hepatic steatosis. A reduced number of individual measurements is likely sufficient for determining an overall UDFF value. TRIAL REGISTRATION. ClinicalTrials.gov: NCT04523584.

Hepatic Steatosis Assessment as a New Strategy for the Metabolic and Nutritional Management of Duchenne Muscular Dystrophy

Growing evidence suggests that patients with Duchenne muscular dystrophy (DMD) have an increased risk of obesity and metabolic syndrome (MetS). The aim of this study was to investigate the potential risk factors for MetS and hepatic steatosis in patients with different stages of DMD. A total of 48 patients with DMD were enrolled and classified into three stages according to ambulatory status. Body mass index (BMI), serum fasting glucose, insulin, and lipid profiles including triglycerides (TG) and high-density lipoprotein were measured, and the homeostatic model assessment for insulin resistance (HOMA-IR) index was evaluated. Ultrasound examinations of the liver were performed to assess hepatic steatosis using the Nakagami parameter index (NPI). The results showed that BMI, TG, HOMA-IR, and ultrasound NPI differed significantly among DMD stages (p < 0.05). In contrast to the low rates of conventional MetS indices, including disturbed glucose metabolism (0%), dyslipidemia (14.28%), and insulin resistance (4.76%), a high proportion (40.48%) of the patients had significant hepatic steatosis. The ultrasound NPI increased with DMD progression, and two thirds of the non-ambulatory patients had moderate to severe hepatic steatosis. Steroid treatment was a risk factor for hepatic steatosis in ambulatory patients (p < 0.05). We recommend that DMD patients should undergo ultrasound evaluations for hepatic steatosis for better metabolic and nutritional management.

Obesity, insulin resistance and their interaction on liver enzymes

Introduction

To investigate weight status, insulin resistance assessed by HOMA-IR, and their interaction on liver function in non-diabetic Chinese adults.

Methods and results

A total of 7066 subjects were included, and divided into normal weight (n = 3447), overweight (n = 2801), and obese (n = 818) groups. Data including weight, height, waist circumference, fasting blood glucose, fasting insulin, total cholesterol, triglycerides, y-glutamyl transferase (GGT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were acquired. In multi-linear regression analysis for liver enzymes as dependent variables, insulin resistance emerged as a determinant of ALT (β = 0.165, P<0.001), AST (β = 0.040, P<0.001) and GGT (β = 0.170, P<0.001) after adjusting for age, sex, body mass index, triglyceride, and cholesterol. Interactions between insulin resistance and weight status by body mass index were observed in ALT (P<0.001), AST (P<0.001) and GGT (P = 0.0418).

Conclusion

Insulin resistance had significant associations with greater risk of elevated ALT, AST and GGT level in non-diabetic Chinese adults, especially among those who were overweight/ obese.

The Role of Elastography in Non-Alcoholic Fatty Liver Disease

The most common liver disease in developing countries is non-alcoholic fatty liver disease (NAFLD). This involves the abnormal accumulation of lipids in the liver, the pathogenesis of the disease being related to dyslipidemia, obesity, insulin resistance and type 2 diabetes. Most often, the diagnosis of NAFLD is incidental, when performing routine blood tests or when performing a transabdominal ultrasound. The NAFLD spectrum ranges from simple forms of hepatic steatosis to the most advanced form of the disease, steatohepatitis (NASH), which in evolution can cause inflammation, fibrosis, cirrhosis of the liver and even liver cancer. For the evaluation of the prognosis and the clinical evolution, the most important parameter to define is the degree of liver fibrosis. Currently, the gold standard remains the liver biopsy, the differentiation between NAFLD and NASH being made only on the basis of histological analysis. However, liver biopsy is an invasive procedure, with numerous risks such as bleeding, lesions of the other organs and complications related to anesthesia, which significantly reduces its widespread use. Moreover, the risk of a false negative result and the increased costs of the procedure further limits its use in current practice. For this reason, non-invasive methods of evaluating the degree of liver fibrosis have gained ground in recent years. Imaging techniques such as elastography have shown promising results in evaluating and staging NAFLD. The aim of this article is to review the current status of the non-invasive tests for the assessment of NAFLD with a focus on the ultrasound-based elastography techniques.

Ultrasound Fatty Liver Indicator: A Simple Tool for Differentiating Steatosis From Nonalcoholic Steatohepatitis: Validity in the Average Obese Population

OBJECTIVES

Steatosis, nonalcoholic steatohepatitis (NASH), and fibrosis/cirrhosis represent a spectrum of fatty liver disease. The ultrasound fatty liver indicator (US-FLI) evaluates ultrasound (US) features to identify stages of fatty liver disease. We hypothesized that US features could be independent predictors of NASH and that the US-FLI differentiates steatosis from NASH in the average obese population.

METHODS

A retrospective analysis of 208 patients with normal (n = 14), steatotic (n = 89), and NASH (n = 105) livers was performed. Liver/biliary disease and a history of alcohol intake were excluded. Ultrasound metrics included liver-kidney contrast, posterior attenuation, vessel blurring, difficulty visualizing the gallbladder wall, difficulty visualizing the diaphragm, and areas of focal fatty sparing. A statistical comparison of the 3 groups as well as fibrosis stage I and II/III NASH groups was performed. Logistic regression identified independent predictors of NASH.

RESULTS

Gallbladder wall visualization and vessel blurring were different between the steatosis and NASH groups (P ≤ .01). Gallbladder wall visualization was specific for NASH (89%), and vessel blurring was sensitive for NASH (93%). A US-FLI score of 4 or lower suggested the absence of NASH (negative predictive value, 88%; sensitivity, 91%). Logistic regression revealed vessel blurring as the only US predictor of NASH (P ≤ .01). However, the area under the curve (0.649) showed poor performance in differentiating steatosis from NASH when the US-FLI score was 5 or higher.

CONCLUSIONS

Our data suggest that the US-FLI may differentiate steatosis from NASH in the average obese population. Vessel blurring and poor gallbladder wall visualization were the most important metrics. Identification of NASH was enhanced by including the US-FLI score with vessel blurring.

The predictive value of the hepatorenal index for detection of impaired glucose metabolism in patients with non-alcoholic fatty liver disease

BACKGROUND/PURPOSE

Non-alcoholic fatty liver disease (NAFLD) patients are at increased risk of liver-related as well as cardiovascular mortality, including diabetes, coronary heart disease, and stroke, independently of traditional cardiovascular risk factors and metabolic syndrome. The aim of this study was to find out the predictive impact of hepatorenal index (HRI) in the detection of impaired glucose metabolism in asymptomatic NAFLD patients.

METHODS

B-mode ultrasound examinations were performed and ultrasound images from all 89 NAFLD patients aged 50.8 ± 10.1 years were analyzed by echogenicity analyzing software and HRI was acquired, and appropriate laboratory tests for liver, glucose, and lipid metabolism were undertaken.

RESULTS

The mean HRI was 1.345 ± 0.189. 23.59% of patients had mild NAFLD (HRI = 1.167 ± 0.041), 64.04% moderate (HRI = 1.401 ± 0.102), and 12.36% patients severe NAFLD (HRI = 1.802 ± 0.098). Impaired glucose metabolism was present in 48.31% of patients. A positive correlation was present between HRI and impaired glucose metabolism (r = 0.335, p = 0.001). The coefficients of determinations R² for linear regression for HRI and glycated hemoglobin (HbA1c) and oral glucose tolerance test (GTT) were 0.05841 and 0.07498, respectively. The cutoff values for HRI in the detection of diabetes and prediabetes, and prediabetes only, were 1.4 and 1.38, respectively. In logistic regression, the β coefficients for oral GTT, HbA1c, or HRI were 0.62042 (p = 0.0002), 2.18036 (p = 0.0033), and 2.36986 (p = 0.012). The hazard ratio (HR) coefficients (exp [b]) for HRI, HbA1c, and oral GTT sorted according to their HR strength were 10.6958, 8.8494, and 1.8597, respectively.

CONCLUSION

Ultrasonographically acquired HRI has a significant predictive impact on the detection of prediabetes and diabetes in patients with NAFLD.

Proportion of NAFLD patients with normal ALT value in overall NAFLD patients: a systematic review and meta-analysis

Background

ALT value is often used to reflect the hepatic inflammation and injury in NAFLD patients, but many studies proved that ALT values were normal in many NAFLD patients. The aim of this study was to identify the summarized proportion of NAFLD patients with normal ALT value in the overall NAFLD patients.

Methods

Electronic databases PubMed, EMBASE, Ovid, and the Cochrane Library were searched for potential studies published from January 1, 2000 to September 30, 2019. Studies that have reported the number of NAFLD or NASH patients with normal and abnormal ALT value were included and analyzed. Abstracts, reviews, case reports, and letters were excluded.

Results

A total of 11 studies with 4084 patients were included for assessing the summarized proportion of NAFLD patients with normal ALT in overall NAFLD patients. As the results shown, the summarized proportion of NAFLD patients with normal ALT value in overall NAFLD patients was 25% (95%CI: 20–31%) which was calculated by the random-effects model. The summarized proportion of NASH patients with normal ALT value in overall NASH patients was 19% (95%CI: 13–27%). Subgroup analysis includes region, study type, diagnostic method, and group size were conducted to investigate the resource of heterogeneity in the summarized proportion of NAFLD and NASH patients with normal ALT value.

Conclusions

25% NAFLD patients and 19% NASH patients possess the normal ALT value in the clinical manifestation. The value of ALT in the clinical diagnosis of NAFLD and NASH remains need be further testified.

Abdominal subcutaneous fat thickness and homeostasis model assessment of insulin resistance as simple predictors of nonalcoholic steatohepatitis

Background: Obesity, insulin resistance, and diabetes are major risk factors for nonalcoholic fatty liver disease (NAFLD). This study aims to evaluate the association between different grades of NAFLD and abdominal subcutaneous fat thickness with the homeostasis model assessment of insulin resistance (HOMA-IR). Methods: In this pilot study, 59 obese nondiabetic participants with NAFLD were enrolled. Total cholesterol, Hb_A1c, and HOMA-IR were measured. Abdominal subcutaneous fat thickness in the midline just below the xiphoid process in front of the left lobe of the liver (LSFT) and in the umbilical region (USFT), and the degree of hepatic steatosis, were evaluated by ultrasound scans, and their correlation with the degree of steatosis and the NAFLD Activity Score in liver biopsy was assessed. Results: Of the 59 studied participants, 15 had mild, 17 had moderate, and 27 had severe hepatic steatosis by abdominal ultrasound. The mean ± SD HOMA-IR level in NAFLD patients was 5.41±2.70. The severity of hepatic steatosis positively correlated with body mass index (P<0.001), HOMA-IR (P<0.001), serum triglycerides (P=0.001), LSFT (P<0.001), and USFT (P<0.001). Receiver operating characteristics analysis showed that LSFT at a cut-off of 3.45 cm is the most accurate predictor of severe hepatic steatosis, with 74.1% sensitivity and 84.4% specificity. The best cut-off of USFT for identifying severe hepatic steatosis is 4.55 cm, with 63% sensitivity and 81.3% specificity. Conclusion: Abdominal subcutaneous fat thicknesses in front of the left lobe of the liver and in the umbilical region, together with HOMA-IR, are reliable indicators of the severity of NAFLD in obese nondiabetic individuals.

Ultrasound Entropy Imaging of Nonalcoholic Fatty Liver Disease: Association with Metabolic Syndrome

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of advanced liver diseases. Fat accumulation in the liver changes the hepatic microstructure and the corresponding statistics of ultrasound backscattered signals. Acoustic structure quantification (ASQ) is a typical model-based method for analyzing backscattered statistics. Shannon entropy, initially proposed in information theory, has been demonstrated as a more flexible solution for imaging and describing backscattered statistics without considering data distribution. NAFLD is a hepatic manifestation of metabolic syndrome (MetS). Therefore, we investigated the association between ultrasound entropy imaging of NAFLD and MetS for comparison with that obtained from ASQ. A total of 394 participants were recruited to undergo physical examinations and blood tests to diagnose MetS. Then, abdominal ultrasound screening of the liver was performed to calculate the ultrasonographic fatty liver indicator (US-FLI) as a measure of NAFLD severity. The ASQ analysis and ultrasound entropy parametric imaging were further constructed using the raw image data to calculate the focal disturbance (FD) ratio and entropy value, respectively. Tertiles were used to split the data of the FD ratio and entropy into three groups for statistical analysis. The correlation coefficient r, probability value p, and odds ratio (OR) were calculated. With an increase in the US-FLI, the entropy value increased (r = 0.713; p < 0.0001) and the FD ratio decreased (r = –0.630; p < 0.0001). In addition, the entropy value and FD ratio correlated with metabolic indices (p < 0.0001). After adjustment for confounding factors, entropy imaging (OR = 7.91, 95% confidence interval (CI): 0.96–65.18 for the second tertile; OR = 20.47, 95% CI: 2.48–168.67 for the third tertile; p = 0.0021) still provided a more significant link to the risk of MetS than did the FD ratio obtained from ASQ (OR = 0.55, 95% CI: 0.27–1.14 for the second tertile; OR = 0.42, 95% CI: 0.15–1.17 for the third tertile; p = 0.13). Thus, ultrasound entropy imaging can provide information on hepatic steatosis. In particular, ultrasound entropy imaging can describe the risk of MetS for individuals with NAFLD and is superior to the conventional ASQ technique.