Performance Characteristics, Intra- and Inter-operator Agreement of Transient Elastography in Pediatric Nonalcoholic Fatty Liver Disease

The evaluation of non-alcoholic fatty liver disease in children with obesity with vibration-controlled transient elastography

INTRODUCTION

Parallel to the worldwide increase in obesity, the epidemic of chronic liver disease is increasing also in pediatric population. Our aim is to provide a different outlook on the current screening confusion in pediatric non-alcoholic fatty liver disease (NAFLD) with the non-invasive vibration-controlled transient elastography (VCTE) method.

MATERIALS AND METHODS

This single-center, cross-sectional, comparative study was performed at the tertiary center, included 95 patients with obesity and 116 controls, both groups were 9-18 years of ages. VCTE examinations performed in all patients. The cut-off values for controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were established by comparing the study and control groups.

RESULTS

The cut-off for CAP was determined as >236 dB/m when comparing the two groups. The AUC was 0.900 (95% CI, 0.851-0.937) and the diagnostic accuracy was 77.9% and 91.4% for sensitivity and specificity, respectively. The cut-off value for LSM >5 kPa was determined by comparison of the two groups. The AUC was 0.794 (95% CI, 0.733-0.846) and the diagnostic accuracies were 50.5% and 90.5% for sensitivity and specificity, respectively.

CONCLUSIONS

There is no benchmark method for screening pediatric NAFLD. However, VCTE is a promising method for screening pediatric NAFLD. It is accessible, repeatable and practical.

Head-to-head comparison of three different US-based quantitative parameters for hepatic steatosis assessment: a prospective study

PURPOSE

To evaluate the diagnostic performance of attenuation coefficient (AC), hepato-renal index (HRI) and controlled attenuation parameter (CAP) in quantitative assessment of hepatic steatosis by employing histopathology as reference standard.

METHODS

Participants with suspected metabolic-associated fatty liver disease (MAFLD) who underwent US-based parameter examinations and liver biopsy were prospectively recruited. The distributions of US parameters across different grades of steatosis were calculated, and diagnostic performance was determined based on the areas under the receiver operating characteristic curve (AUC).

RESULTS

A total of 73 participants were included, with hepatic steatosis grades S0, S1, S2, and S3 distributed as follows: 13, 20, 27, and 13 respectively. The correlation coefficients for CAP, AC, and HRI ranged from 0.67 to 0.74. AC and HRI showed a strong correlation with steatosis grade. The AUC for CAP and AC in diagnosing steatosis ≥ S1 were significantly higher at 0.99 and 0.98 compared to HRI's value. For diagnosing steatosis ≥ S2, the AUC of CAP (AUC: 0.85) was lower than that of AC (AUC: 0.94), and HRI (AUC: 0.94). Similarly for diagnosing steatosis S3, the AUC of CAP (AUC: 0.68) was lower than that of AC (AUC: 0.88), and HRI (AUC: 0.88).

CONCLUSION

The AC and HRI values increased with the progression of hepatic steatosis grade, while CAP increased from S0 to S2 but not from S2 to S3. For mild steatosis diagnosis, CAP and AC showed superior diagnostic performance compared to HRI, while AC and HRI were more advantageous in differentiating moderate and severe steatosis.

Clinical Performance of Transient Elastography With Comparison to Quantitative Magnetic Resonance Imaging, Ultrasound, and Biopsy in Children and Adolescents With Known or Suspected Fatty Liver Disease

Background: Performance of vibration-controlled transient elastography (VCTE) is inadequately validated in pediatric nonalcoholic fatty liver disease (NAFLD). We aimed to assess the technical performance of VCTE in pediatric NAFLD and define the agreement between VCTE and reference standards of imaging and/or biopsy. Methods: This prospective study recruited participants with known or suspected NAFLD who underwent a research VCTE examination (FibroScan Mini 430). Ten valid VCTE liver stiffness measurements (kPa) and controlled attenuation parameter (CAP) (dB/m) measurements were obtained for each participant. Available clinically acquired MR elastography and magnetic resonance imaging proton density fat fraction (PDFF), liver ultrasound shear wave elastography, and biopsy served as references standards. Results: Eighty-four consecutive participants were included (55 males, mean age 15.0 ± 3.5 years, mean BMI 36.6 ± 9.4 kg/m2). VCTE examinations were complete in 80/83 participants. 37/83 participants were examined with an XL probe. There was no significant correlation between CAP and PDFF [n = 16; r = 0.17 (95% confidence interval [CI]: -0.34 to 0.61), p = 0.5] or between VCTE liver stiffness and MR elastography stiffness [n = 27; r = 0.31 (95% CI: -0.07 to 0.62), p = 0.10]. For prediction of any fibrosis stage ≥1 on biopsy (n = 9/15 participants), VCTE median liver stiffness >5.1 kPA had an area under receiver operating characteristic curve of 0.52 (95% CI: 0.26-0.78) with a sensitivity of 88.9% and specificity of 16.6% (p > 0.99). Conclusions: Complete VCTE examinations could be obtained in most pediatric patients with NAFLD. Neither VCTE liver stiffness nor CAP correlated well with measures of liver fat or stiffness by established imaging modalities and biopsy.

Agreement and reliability of hepatic transient elastography in patients with chronic hepatitis C: A cross-sectional test-retest study

Background and Aims

Transient elastography (TE) has largely replaced liver biopsy to evaluate fibrosis stage and cirrhosis in chronic hepatitis C. Previous studies have reported excellent reliability of TE but agreement metrics have not been reported. This study aimed to assess interrater agreement and reliability of repeated TE measurements.

Methods

Two operators performed TE independently, directly after each other. The primary outcome was disagreement, defined as a difference in TE results between operators of ≥33%, as well as the smallest detectable change, SDC95 (i.e., the difference between measurements needed to state with 95% certainty that there is a difference in underlying stiffness). Secondary outcomes included reliability, measured as intraclass correlation (ICC), and patient and examination characteristics associated with the agreement.

Results

In total, 65 patients were included, with a mean liver stiffness of 9.7 kPa. Of these, 21 (32%) had a disagreement in TE results of ≥33% between the two operators. The SDC95 on the log scale was 1.97, indicating that an almost twofold increase or decrease in liver stiffness would be required to confidently represent a change in the underlying fibrosis. Reliability, estimated using the ICC, was acceptable at 0.86. In a post hoc analysis, fasting less than 5 h before TE was associated with a higher degree of disagreement (48% vs. 19%, p = 0.03).

Conclusions

In our clinical setting, interrater agreement in directly repeated TE measurements was surprisingly low. It is essential to further investigate the reliability and agreement of TE to determine its validity and usefulness.

Clinical correlation of 2D shear wave elastography findings in children with type 1 diabetes mellitus without autoimmune thyroiditis

OBJECTIVES

The aim of study was to evaluate the 2D shear wave sonoelastography (SWE) findings of the thyroid gland in children with type 1 diabetes mellitus (T1DM) with normal gray-scale findings and without thyroid autoimmunity (AIT) and obtain data that will be useful for the early detection of glandular involvement.

METHODS

The study included 46 T1DM patients (mean age: 11.28 ± 3.3 years) and 46 healthy children (mean age: 12.01 ± 3.8 years) as the control group. The thyroid gland mean elasticity value was obtained as kPa and compared in groups. A correlation was investigated between elasticity values and age at diabetes, serum free T4, thyroid stimulating hormone (TSH), anti-thyroglobulin, anti-tissue peroxidase, and hemoglobin A1c values.

RESULTS

No difference was found between T1DM patients and the control group in the thyroid 2D SWE evaluation (the median kPa value: 17.1 (10.2) in the study group and 16.8 (7.0) in the control group) (p=0.15). No significant correlation was found between 2D SWE kPa values and age at diagnosis, serum free T4, TSH, anti-thyroglobulin, anti-tissue peroxidase, and hemoglobin A1c levels in T1DM patients.

CONCLUSIONS

Our study showed that the elasticity of the thyroid gland in T1DM patients without AIT was not affected differently from that of the normal population. If 2D SWE is used in routine follow-up in T1DM patients before the development of AIT, we think that it will be useful in the early detection of thyroid gland affections and AIT, and long-term comprehensive studies in this direction will contribute to the literature.

Transient Elastography Measures of Hepatic Steatosis and Fibrosis Are Associated With Body Composition Among US Adolescents

OBJECTIVES

Obesity-related fatty liver disease impacts long-term adolescent liver health. We examined transient elastography assessed hepatic steatosis and fibrosis distributions and relationships with body composition and lifestyle factors in a United States national adolescent population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 1080 non-Hispanic white, non-Hispanic black, non-Hispanic Asian, and Hispanic boys and girls aged 12-19 years in the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Participants underwent anthropometry and dual-energy x-ray absorptiometry (DXA).

RESULTS

Compared with girls, boys had higher mean CAP (223.7 dB/m vs 215.3 dB/m) and liver stiffness (5.1 kPa vs 4.9 kPa). CAP and liver stiffness increased markedly with body mass index (BMI). In multivariable-adjusted analysis, CAP in the upper quartile was associated with Hispanic and non-Hispanic Asian ethnicity and increased BMI, waist-to-hip ratio, systolic blood pressure, and sedentary time, and decreased physical activity and Healthy Eating Index-2015 score. In multivariable-adjusted analysis, liver stiffness in the upper quartile was associated with male sex, non-Hispanic black ethnicity, and increased BMI, alanine aminotransferase, CAP, and serum cotinine. DXA total percent fat and trunk fat percent were positively related to CAP ( P < 0.001 for each), but not to liver stiffness with multivariable adjustment. Results were similar with CAP and liver stiffness as continuous characteristics.

CONCLUSIONS

In US adolescents, increased anthropometric and DXA body composition measures and lifestyle factors were associated with higher CAP and liver stiffness. Transient elastography and similar noninvasive markers may be utilized for early detection of liver disease in high-risk pediatric populations.

Metabolic, behavioral health, and disordered eating comorbidities associated with obesity in pediatric patients: An Obesity Medical Association (OMA) Clinical Practice Statement 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) details metabolic, behavioral health, and disordered eating comorbidities associated with obesity in children. This CPS will be followed by a companion CPS covering further comorbidities, including genetics and social consequences related to overweight and obesity. These CPSs are intended to provide clinicians with an overview of clinical practices applicable to children and adolescents with body mass indices greater than or equal to the 95th percentile for their ages, particularly those with adverse consequences resulting from increased body mass. The information in this CPS is based on scientific evidence, supported by the medical literature, and derived from the clinical experiences of members of the OMA.

Methods

The scientific information and clinical guidance in this CPS is based upon referenced evidence and derived from the clinical perspectives of the authors.

Results

This OMA statement details metabolic, behavioral health, and disordered eating comorbidities associated with obesity in children. It provides clinical information regarding identifying and treating metabolic, behavioral health, and disordered eating comorbidities associated with obesity in children over the 95th percentile of weight/height for age.

Conclusions

This OMA clinical practice statement details metabolic, behavioral health, and disordered eating comorbidities associated with obesity in children and provides an overview of current recommendations. These recommendations lay out a roadmap to the improvement of the health of children and adolescents with obesity, especially those with metabolic, physiological, and psychological complications.

American Association of Clinical Endocrinology Clinical Practice Guideline for the Diagnosis and Management of Nonalcoholic Fatty Liver Disease in Primary Care and Endocrinology Clinical Settings: Co-Sponsored by the American Association for the Study of Liver Diseases (AASLD)

OBJECTIVE

To provide evidence-based recommendations regarding the diagnosis and management of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) to endocrinologists, primary care clinicians, health care professionals, and other stakeholders.

METHODS

The American Association of Clinical Endocrinology conducted literature searches for relevant articles published from January 1, 2010, to November 15, 2021. A task force of medical experts developed evidence-based guideline recommendations based on a review of clinical evidence, expertise, and informal consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RECOMMENDATION SUMMARY

This guideline includes 34 evidence-based clinical practice recommendations for the diagnosis and management of persons with NAFLD and/or NASH and contains 385 citations that inform the evidence base.

CONCLUSION

NAFLD is a major public health problem that will only worsen in the future, as it is closely linked to the epidemics of obesity and type 2 diabetes mellitus. Given this link, endocrinologists and primary care physicians are in an ideal position to identify persons at risk on to prevent the development of cirrhosis and comorbidities. While no U.S. Food and Drug Administration-approved medications to treat NAFLD are currently available, management can include lifestyle changes that promote an energy deficit leading to weight loss; consideration of weight loss medications, particularly glucagon-like peptide-1 receptor agonists; and bariatric surgery, for persons who have obesity, as well as some diabetes medications, such as pioglitazone and glucagon-like peptide-1 receptor agonists, for those with type 2 diabetes mellitus and NASH. Management should also promote cardiometabolic health and reduce the increased cardiovascular risk associated with this complex disease.

Accuracy of attenuation imaging in the assessment of pediatric hepatic steatosis: correlation with the controlled attenuation parameter

PURPOSE

This study evaluated the accuracy of attenuation imaging (ATI) for the assessment of hepatic steatosis in pediatric patients, in comparison with the FibroScan vibration-controlled transient elastography controlled attenuation parameter (CAP).

METHODS

Consecutive pediatric patients referred for evaluation of obesity who underwent both ATI and FibroScan between February 2020 and September 2021 were included. The correlation between attenuation coefficient (AC) and CAP values was assessed using the Spearman test. The AC cutoff value for discriminating hepatic steatosis corresponding to a CAP value of 241 dB/m was calculated. Multivariable linear regression analysis was performed to estimate the strength of the association between AC and CAP. The diagnostic accuracy of AC cutoffs was estimated using the imperfect gold-standard methodology based on a two-level Bayesian latent class model.

RESULTS

Seventy patients (median age, 12.5 years; interquartile range, 11.0 to 14.0 years; male:female, 58:12) were included. AC and CAP showed a moderate-to-good correlation (ρ =0.646, P<0.001). Multivariable regression analysis affirmed the significant association between AC and CAP (P<0.001). The correlation was not evident in patients with a body mass index ≥30 kg/m2 (ρ=-0.202, P=0.551). Linear regression revealed that an AC cutoff of 0.66 dB/cm/MHz corresponded to a CAP of 241 dB/m (sensitivity, 0.93; 95% confidence interval [CI], 0.85 to 0.98 and specificity, 0.87; 95% CI, 0.56 to 1.00).

CONCLUSION

ATI showed an acceptable correlation with CAP values in a pediatric population, especially in patients with a body mass index <30 kg/m2. An AC cutoff of 0.66 dB/cm/MHz, corresponding to a CAP of 241 dB/m, can accurately diagnose hepatic steatosis.

Effect of skin-capsular distance on controlled attenuation parameter for diagnosing liver steatosis in patients with nonalcoholic fatty liver disease

The effect of the skin-capsular distance (SCD) on the controlled attenuation parameter (CAP) for diagnosis of liver steatosis in patients with nonalcoholic fatty liver disease (NAFLD) remains unclear. The SCD was measured using B-mode ultrasound, and the CAP was measured using the M probe of FibroScan®. According to the indications of the M probe, 113 patients with an SCD of ≤ 25 mm were included in the present study. The association between the SCD and CAP was investigated, and the diagnostic performance of the SCD-adjusted CAP was tested. The SCD showed the most significant positive correlation with the CAP (ρ = 0.329, p < 0.001). In the multiple regression analysis, the SCD and serum albumin concentration were associated with the CAP, independent of pathological liver steatosis. According to the multivariate analysis, two different formulas were developed to obtain the adjusted CAP using the SCD and serum albumin concentration as follows: adjusted CAP (dB/m) = CAP - (5.26 × SCD) and adjusted CAP (dB/m) = CAP - (5.35 × SCD) - (25.77 × serum albumin concentration). The area under the receiver operating characteristic curve for diagnosis of a steatosis score ≥ 2 of adjusted CAP was 0.678 and 0.684 respectively, which were significantly greater than the original CAP (0.621: p = 0.030 and p = 0.024). The SCD is associated with the CAP independent of liver steatosis. Adjustment of the CAP using the SCD improves the diagnostic performance of the CAP in NAFLD.

Non-Alcoholic Fatty Liver Disease in Children

Background and Objectives: The prevalence of pediatric non-alcoholic fatty liver disease is increasing. A lot of new data are published regularly. Materials and Methods: Original clinical studies, review articles, and guidelines in children were searched for and the most relevant included in this review. Results: A total of 138 retrieved papers were classified into pathogenesis, epidemiology, diagnosis, and treatment. Pathogenesis is currently explained with the “multi hit hypothesis”, with complex interactions of genetic and environmental factors which trigger inflammation in steatotic liver. The prevalence is rising. A diagnosis can be made with laboratory tests, imaging, and liver biopsy after the exclusion of other causes of liver steatosis. The mainstay of treatment is lifestyle modification consisting of dietary intervention and increased physical activity. The progression to liver cirrhosis can occur even in children. Conclusions: Non-alcoholic fatty liver disease in children is a part of a metabolic syndrome in the majority of patients. Due to its complex etiology and high prevalence, multidisciplinary teams, together with public health professionals, should be involved in its treatment.