The Application of Liver Stiffness Measurement in Residents Without Overt Liver Diseases Through a Community-Based Screening Program

2019 Global NAFLD Prevalence: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD.

METHODS

Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence.

RESULTS

We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%.

CONCLUSIONS

Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.

Noninvasive Algorithms for the Case Finding of "At-Risk" Patients with NAFLD

Despite the high prevalence of non-alcoholic fatty liver disease (NAFLD) in primary care (25%), only a small minority (< 5%) of NAFLD patients will develop advanced liver fibrosis. The challenge is to identify these patients, who are at the greatest risk of developing complications and need to be referred to liver clinics for specialized management. The focus should change from patients with abnormal liver tests toward patients "at risk of NAFLD," namely those with metabolic risk factors, such as obesity and type 2 diabetes. Non-invasive tests are well validated for diagnosing advanced fibrosis. Algorithms using FIB-4 as the first-line test, followed, if positive (≥ 1.3), by transient elastography or a patented blood test are the best strategy to define pathways for "at-risk" NAFLD patients from primary care to liver clinics. Involving general practitioners actively and raising their awareness regarding NAFLD and non-invasive tests are critical to establish such pathways.

Impact of non-invasive biomarkers on hepatology practice: Past, present and future

Over the last two decades, there have been tremendous advances in the non-invasive diagnosis and risk stratification of chronic liver diseases (CLDs). Non-invasive approaches are based on the quantification of biomarkers in serum samples or on the measurement of liver stiffness, using either ultrasound- or magnetic resonance-based elastography techniques. The fibrosis-4 index (non-patented) and enhanced liver fibrosis test (patented) are the most widely adopted serum markers, whereas vibration-controlled transient elastography is the most widely adopted elastography technique. In this review, we discuss the role of non-invasive tests in the current era, as well as their accuracy and how their use in clinical practice has changed the practice of hepatology, including identification of early cirrhosis in patients with risk factors for CLD, diagnosis of portal hypertension, establishing prognosis in compensated cirrhosis, guiding antiviral treatment, and screening for fibrosis and cirrhosis in primary care.

Range of Normal Liver Stiffness and Factors Associated With Increased Stiffness Measurements in Apparently Healthy Individuals

BACKGROUND & AIMS

Transient elastography (TE) is a noninvasive technique used to measure liver stiffness to estimate the severity of fibrosis. The range of liver stiffness measurements (LSMs) in healthy individuals is unclear. We performed a systematic review to determine the range of LSMs, examined by TE, in healthy individuals and individuals who are susceptible to fibrosis.

METHODS

We collected data from 16,082 individuals, in 26 cohorts, identified from systematic searches of Embase, Ovid MEDLINE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for studies of liver stiffness measurements. Studies analyzed included apparently healthy adults (normal levels of liver enzymes, low-risk alcohol use patterns, and negative for markers of viral hepatitis). The presence of diabetes, hypertension, dyslipidemia, or steatosis, based on ultrasound examination, was known for most participants. We performed a meta-analysis of data from individual participants. The cohort was divided into 4 groups; participants with a body mass index <30 kg/m² were examined with the medium probe and those with a body mass index ≥30 kg/m² were examined with the extra-large probe. Linear regression models were conducted after adjusting for potential confounding factors of LSMs. We performed several sensitivity analyses.

RESULTS

We established LSM ranges for healthy individuals measured with both probes-these did not change significantly in sensitivity analyses of individuals with platelets ≥150,000/mm³ and levels of alanine aminotransferase ≤33 IU/L in men or ≤25 IU/L in women. In multivariate analysis, factors that modified LSMs with statistical significance included diabetes, dyslipidemia, waist circumference, level of aspartate aminotransferase, and systolic blood pressure at examination time. Significant increases in LSMs were associated with the metabolic syndrome in individuals examined by either probe. Diabetes in obese individuals increased the risk of LSMs in the range associated with advanced fibrosis.

CONCLUSIONS

In a systematic review and meta-analysis of data from individual participants, we established a comprehensive set of LSM ranges, measured by TE in large cohorts of healthy individuals and persons susceptible to hepatic fibrosis. Regression analyses identified factors associated with increased LSMs obtained by TE with the medium and extra-large probes.

Comparison of FIB-4 and transient elastography in evaluating liver fibrosis of chronic hepatitis C subjects in community

Background and aim

The role of non-invasive methods to evaluate fibrosis severity of chronic hepatitis C (CHC) subjects in community needs to be explored. This study investigated FIB-4 and transient elastography (TE) in staging liver fibrosis of CHC subjects in community.

Methods

A total of 905 subjects who were positive for anti-HCV antibody from five districts of Tainan City of Taiwan were invited to participate in surveillance activities for CHC. FIB-4 and TE were measured for each participant.

Results

A total of 502 subjects with detectable HCV RNA and valid TE were enrolled. The distribution of FIB-4 and TE values differed markedly. Both methods exhibited a strongest correlation in subjects with at age 50~60 years (r = 0.655, p <0.001). FIB-4 score increased proportionally with age (p <0.001), but TE did not (p = 0.142). The intraclass correlation efficient of both methods was 0.255 (p <0.001). Subjects with TE defined advanced fibrosis exhibited younger age, higher BMI, higher platelet count, lower FIB-4 score, higher incidence of fatty liver and splenomegaly, and higher controlled attenuation parameter value than those defined by FIB-4. By multivariate logistic regression analysis, higher ALT levels, higher incidence of fatty liver, and presence of splenomegaly were the independent factors associated with advanced fibrosis defined by TE rather than defined by FIB-4.

Conclusions

FIB-4 and TE defined different distribution of fibrosis stages in same HCV population. FIB-4 was deeply influenced by age whereas TE was not. TE had the advantages over than FIB-4 in strong association with splenomegaly and in detecting the role of non-alcoholic fatty liver disease in advanced fibrosis.

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.

The characteristics of residents with unawareness of hepatitis C virus infection in community

BACKGROUND

Control of hepatitis C virus infection (HCV) is an increasingly important issue. Enhancing screening coverage is necessary to discover more HCV infected subjects in community. However, a substantial population is unaware of HCV infection that needs more attention.

AIM

The aims of this study were to evaluate the status of HCV infected residents in remote villages, to compare characteristics between already known and unaware HCV infection subjects, and to analyze the disease insights.

PATIENTS AND METHODS

Screening intervention for liver diseases was conducted in remote villages of Tainan City of southern Taiwan from August 2014 to July 2016. Items of screening examinations included questionnaire, blood sampling for liver tests and viral hepatitis markers (hepatitis B surface antigen and anti-HCV antibody), abdominal sonography survey, and liver stiffness measurement by transient elastography. Quantitation of HCV RNA was measured for residents with positive anti-HCV antibody.

RESULTS

A total of 194 (13.5%) out of 1439 participants showed positive for anti-HCV antibody. HCV viremia was detected in 119 (61.3%) residents. Previously unaware HCV infection by questionnaire record was present in 68 (35.1%) of ant-HCV positive residents. By multivariate logistic analysis, unaware HCV infected residents exhibited significantly mild liver fibrosis (OR 0.876, 95% CI 0.782~0.981, p = 0.022), more prevalent of heart diseases (OR 6.082, 95% CI 1.963~18.839, p = 0.002), and less cluster of family history of liver diseases (OR 0.291, 95% CI 0.113~0.750, p = 0.011) when comparing with already known HCV infected residents. Among the 126 already know HCV infected residents, only 59 (46.8%) received antiviral treatment or regular follow-up. No concept or no willing to receive medical care was observed in 44 (34.9%) residents.

CONCLUSION

In HCV endemic villages of Taiwan, residents with unaware HCV infection comprised about one third of HCV infected residents and exhibited obscure characteristics to identify. Less than half of already known HCV infected residents received adequate medical care. To eliminate HCV infection, vigorous efforts on enhancing screening coverage, educating update knowledge of liver diseases, and linking to medical care are urgently needed.

Risk Assessment of Hepatocellular Carcinoma in General Population by Liver Stiffness in Combination with Controlled Attenuation Parameter using Transient Elastography: A Cross Sectional Study

BACKGROUND

Hepatocellular carcinoma (HCC) in patients without hepatitis B (HBV) and -C virus (HCV) infection are increasing in Japan. Method for detecting high-risk liver diseases of HCC in general population has still not been established. Liver stiffness measurement (LSM) and Controlled Attenuation Parameter (CAP) using transient elastography (TE; FibroScan System) are useful for detecting liver fibrosis and steatosis. The aim of this study is to clarify TE for risk assessment of HCC in general population.

METHODS

This cross-sectional study was performed for residents aged ≥ 40 years in an intermountain town in Japan with a population of 3,493. Blood laboratory testing included tumor markers, abdominal ultrasound (AUS), and TE was performed.

RESULTS

Among 175 subjects (64 men, 111 women), TE was evaluated and three patients with HCC were detected by AUS. For detecting HCC, the cut-off value of LSM was 5.3 kPa sensitivity 100%, specificity 75%, AUROC 0.88). The combination of LSM and CAP (LSM > 5.3 kPa with any CAP and CAP > 248 dB/m with any LSM) could detect the high-risk liver diseases of HCC (HCC, nonalcoholic fatty liver/steatohepatitis, HBV or HCV related chronic viral hepatitis with alanine transaminase (ALT) > 30 IU/L for men or > 19 IU/L for women or cirrhosis of any cause) with high sensitivity (sensitivity 90%, specificity 55%, positive predictive value 10%, negative predictive value 99%, P = 0.006).

CONCLUSION

The combination of LSM and CAP can be useful in detecting high-risk liver diseases of HCC out of general population.

Comparison of collagen proportionate areas in liver fibrosis quantification between chronic hepatitis B and C

Few studies have compared the distinct hepatic collagen morphometrics of chronic hepatitis B (CHB) and chronic hepatitis C (CHC). This study compared the discrepancies between CHB and CHC in liver fibrosis (F) quantification by using the collagen proportionate area (CPA) and liver stiffness (LS) measured with shear wave velocity (SWV).This study enrolled 274 eligible consecutive patients diagnosed with CHB (n = 137) or CHC (n = 137). Their ages ranged from 20 to 80 years (median = 50). In total, 154 patients (56.2%) were male. Participant LS was measured by using acoustic radiation force impulse elastography preceding an immediate percutaneous liver biopsy. The total proportion of the collagen stained with picrosirius red to the total tissue area was expressed as the CPA percentage, which was stratified into portal-bridging (PB) and perisinusoidal (PS) proportionate areas (PAs).Based on the METAVIR F staging system, 36 (26.3%), 36 (26.3%), 28 (20.4%), and 37 (27.0%) participants in the CHB group and 34 (24.8%), 45 (32.9%), 34 (24.8%), and 24 (17.5%) participants in the CHC group were staged as F1, F2, F3, and F4, respectively. Both the total CPAs and PBPAs were significantly (P < 0.05) higher in the CHC group than in the CHB group within all F-stratified subgroups. The SWVs were significantly (P < 0.05) higher in the CHC group than in the CHB group only within the F2, F3, and F4 subgroups. However, the PSPAs did not differ significantly between the CHC and CHB groups within all subgroups. Multiple regression analysis revealed that viral hepatitis etiology (P < 0.001), METAVIR F stages (P < 0.001), and platelet count (P = 0.007) were independent factors correlated with the CPA (R = 0.543, P < 0.001).In conclusion, both the F stage-stratified CPAs and SWVs tended to be higher in cases of CHC than in those of CHB. The type of viral hepatitis significantly affected both the CPA and SWV values. The PBPAs were more closely correlated with F stages and SWV than were the PSPAs.

Erratum: The Application of Liver Stiffness Measurement in Residents Without Overt Liver Diseases Through a Community-Based Screening Program: Erratum

[This corrects the article DOI: 10.1097/MD.0000000000003193.].