Diagnostic performances of Fibrosis-4 index and nonalcoholic fatty liver disease fibrosis score in metabolic dysfunction-associated steatotic liver disease in Asian primary care clinics.

AIMS: We aimed to explore the extent to which individuals previously diagnosed with nonalcoholic fatty liver disease (NAFLD) meet the criteria fulfilled with the new nomenclature, metabolic dysfunction-associated steatotic liver disease (MASLD), within an Asian primary clinic cohort. Additionally, we assessed the reliability of the diagnostic performance of FIB-4 and NAFLD fibrosis score (NFS) for MASLD within the primary clinic cohort. METHODS: This retrospective cross-sectional study included participants who underwent magnetic resonance elastography and abdominal ultrasonography during their health checkups at nationwide health promotion centers (n = 6740). RESULTS: The prevalence rates of NAFLD and MASLD diagnosed based on ultrasonography results were 36.7% and 38.0%, respectively. Notably, 96.8% of patients in the NAFLD cohort fulfilled the new criteria for MASLD. A small proportion of patients with NAFLD (n = 80, 3.2%) did not meet the MASLD criteria. Additionally, 168 patients (6.6%) were newly added to the MASLD group. The areas under the receiver operating characteristic curves for diagnosing advanced hepatic fibrosis for FIB-4 (0.824 in NAFLD vs. 0.818 in MASLD, p = 0.891) and NFS (0.803 in NAFLD vs. 0.781 in MASLD, p = 0.618) were comparable between the MASLD and NAFLD groups. Furthermore, the sensitivity, specificity, positive predictive value, and negative predictive value of FIB-4 and NFS for advanced fibrosis in MASLD were also comparable to those in NAFLD. CONCLUSIONS: Most patients (96.8%) previously diagnosed with NAFLD fulfilled the new criteria for MASLD in an Asian primary clinic cohort. Diagnostic performance of FIB-4 in the MASLD cohort demonstrated satisfactory results.

Comparative evaluation of non-invasive tests for risk stratification for cause specific mortality in at-risk population of hepatic fibrosis.

Our study aimed to conduct a comparative evaluation of various noninvasive tests (NITs) for risk stratification in at-risk population for non-alcoholic fatty liver disease (NAFLD), focusing on cardiovascular and liver-related mortality. A total of 21,715 adults aged 40 years and older were enrolled at baseline. The mean follow-up period was 12.39 years. Three types of NITs (fibrosis-4 index [FIB-4], NAFLD fibrosis score [NFS], and steatosis-associated fibrosis estimator [SAFE] score) were used. When using the low cut-off as a 'rule-out' strategy, there were no significant differences in cardiovascular mortality between the 'rule-out' (low-risk) group and the 'rule-in' (intermediate- or high-risk) group based on FIB-4 (aHR = 1.029, P = 0.845) or NFS (aHR = 0.839, P = 0.271) classification. However, the SAFE score exhibited higher sensitivity in predicting cardiovascular mortality compared to FIB-4 or NFS (73.3% in SAFE score vs. 29.6% in FIB-4 or 21.3% in NFS). Only the SAFE score could effectively differentiate the risk between low- and intermediate- or high-risk groups for all types of mortality (all P values for aHR < 0.001). The low cutoff value of the SAFE score discriminated not only liver-related mortality but also identified the cardiovascular high-risk group in the community cohort.

Cost-effectiveness study of FIB-4 followed by transient elastography screening strategy for advanced hepatic fibrosis in a NAFLD at-risk population.

BACKGROUND & AIMS: The cost-effectiveness to screen hepatic fibrosis in at-risk population as recommended by several professional societies has been limited. This study aimed to investigate the cost-effectiveness of this screening strategy in the expanded at-risk population recently proposed by several societies. METHODS: A combined model of the decision tree and Markov models was developed to compare expected costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio (ICER) between screening and no screening groups. The model included liver disease-related health states and cardiovascular disease (CVD) states as a base-case analysis. Screening strategy consisted of fibrosis-4 index (FIB-4) followed by vibration-controlled transient elastography (VCTE) and intensive lifestyle intervention (ILI) as a treatment for diagnosed patients. RESULTS: Cost-effectiveness analysis showed that screening the at-risk population entailed $298 incremental costs and an additional 0.0199 QALY per patient compared to no screening (ICER $14 949/QALY). Screening was cost-effective based on the implicit ICER threshold of $25 000/QALY in Korea. When the effects of ILI on CVD and extrahepatic malignancy were incorporated into the cost-effectiveness model, the ICER decreased by 0.85 times from the base-case analysis (ICER $12 749/QALY). In contrast, when only the effects of liver disease were considered in the model, excluding cardiovascular disease effects, ICER increased from the baseline case analysis to $16 305. Even when replacing with medical costs in Japan and U.S., it remained cost-effective with the estimate below the countries' ICER threshold. CONCLUSIONS: Our study provides compelling evidence supporting the cost-effectiveness of FIB-4-based screening the at-risk population for advanced hepatic fibrosis.

Genetic and Metabolic Characteristics of Lean Nonalcoholic Fatty Liver Disease in a Korean Health Examinee Cohort.

Background/Aims: The pathophysiology of lean nonalcoholic fatty liver disease (NAFLD) is unclear but has been shown to be associated with more diverse pathogenic mechanisms than that of obese NAFLD. We investigated the characteristics of genetic or metabolic lean NAFLD in a health checkup cohort. Methods: This retrospective cross-sectional study analyzed single nucleotide polymorphism data for 6,939 health examinees. Lean individuals were categorized according to a body mass index cutoff of 23 kg/m2. Single nucleotide polymorphisms were analyzed using genotyping arrays. Results: The prevalence of lean NAFLD was 21.6% among all participants with NAFLD, and the proportion of lean NAFLD was 18.5% among lean participants. The prevalence of metabolic syndrome and diabetes among lean patients with NAFLD was 12.4% and 10.4%, respectively. Lean NAFLD appeared to be metabolic-associated in approximately 20.1% of patients. The homozygous minor allele (GG) of PNPLA3 (rs738409) and heterozygous minor alleles (CT, TT) of TM6SF2 (rs58542926) were associated with lean NAFLD. However, the prevalence of fatty liver was not associated with the genetic variants MBOAT7 (rs641738), HSD17B13 (rs72613567), MARC1 (rs2642438), or AGXT2 (rs2291702) in lean individuals. Lean NAFLD appeared to be associated with PNPLA3 or TM6SF2 genetic variation in approximately 32.1% of cases. Multivariate risk factor analysis showed that metabolic risk factors, genetic risk variants, and waist circumference were independent risk factors for lean NAFLD. Conclusions: In a considerable number of patients, lean NAFLD did not appear to be associated with known genetic or metabolic risk factors. Further studies are required to investigate additional risk factors and gain a more comprehensive understanding of lean NAFLD.

Diagnostic performance of the fibrosis-4 index and the NAFLD fibrosis score for screening at-risk individuals in a health check-up setting.

BACKGROUND: The fibrosis-4 index (FIB-4) and the NAFLD fibrosis score (NFS) have been used as noninvasive screening methods for advanced fibrosis in patients with NAFLD. However, their diagnostic performance has not been evaluated in at-risk individuals regardless of hepatic steatosis. This study evaluated the performance of the FIB-4 and NFS in at-risk groups of health check-up examinees at mass screening centers. METHODS: This retrospective, cross-sectional study included 8545 participants who underwent voluntary magnetic resonance elastography at a discounted fee during their regular health check-ups at 13 mass screening centers nationwide. The at-risk group was defined as those with any of the following conditions: NAFLD, 2 or more metabolic abnormalities, diabetes mellitus, or abnormal aminotransferase levels. A magnetic resonance elastography cutoff of ≥3.6 kPa was used to define conventional advanced fibrosis. RESULTS: According to the proposed criteria, the proportion of at-risk individuals was 67.4%-80.2% in the health check-up cohort without viral or alcohol-associated liver disease. The prevalence of individuals with advanced hepatic fibrosis in each at-risk group was ~2.3%-2.8% according to various criteria. It was higher in patients without NAFLD than in those with NAFLD. A total of 28.2%-39.6% of those in each at-risk group did not show hepatic steatosis on ultrasonography. The performance of FIB-4 for advanced fibrosis in the at-risk group was comparable with that in the NAFLD group. FIB-4 showed a better area under the receiver operating characteristic curve and sensitivity than NFS in the at-risk group. CONCLUSIONS: FIB-4 demonstrated superior performance compared with the NFS, and its performance in at-risk individuals was similar to that observed for patients with NAFLD.

A survey on the awareness, current management, and barriers for non-alcoholic fatty liver disease among the general Korean population.

Non-alcoholic fatty liver disease (NAFLD) is often diagnosed incidentally during medical evaluation for diseases other than liver disease or during health checkups. This study aimed to investigate the awareness, current status, and barriers to the management of NAFLD in the general population. This cross-sectional study used an online survey, which consisted of 3-domain and 18-item questionnaires. The content validity index for each item of the questionnaire was rated above 0.80. Most respondents (72.8%) reported having heard of the term 'NAFLD', and a large proportion of the general population (85.7%) recognized the possibility of developing fatty liver without consuming alcohol. Awareness of the terminology of NAFLD and that NAFLD is a disease that needs to be managed is relatively high. However, the knowledge that NAFLD can progress to end-stage liver disease and new cardiovascular diseases is lacking. Only 25.7% of the general population is aware that NAFLD increases the incidence of heart and cerebrovascular diseases. Only 44.7% of those who were incidentally diagnosed during a health check-up were provided with any specific guidance on NAFLD, and more than half (55.3%) were not provided with education or guidance on NAFLD or did not remember it. Only 40.2% of people diagnosed with NAFLD incidentally visited a clinic. The reason for not visiting a clinic for the evaluation of NAFLD varied greatly depending on sex and age group. Only 40.2% of patients visited the clinic after being diagnosed with NAFLD. The reasons for not visiting the clinic after NAFLD diagnosis differed significantly according to sex and age.

Diagnostic Performance of the Fibrosis-4 Index and Nonalcoholic Fatty Liver Disease Fibrosis Score in Lean Adults With Nonalcoholic Fatty Liver Disease.

IMPORTANCE: The diagnostic performance of the fibrosis-4 index (FIB-4) and nonalcoholic fatty liver disease (NAFLD) fibrosis score (NFS) for advanced fibrosis in lean patients with NAFLD is limited. OBJECTIVE: To evaluate the diagnostic performance of the FIB-4 and NFS in lean individuals with NAFLD. DESIGN, SETTING, AND PARTICIPANTS: This diagnostic study included adults with biopsy-proven NAFLD from 6 referral centers in Asia from 1995 to 2019. Cohorts were matched by age and sex between the lean and nonlean groups. All statistical analyses were executed from October 2022 to March 2023. MAIN OUTCOMES AND MEASURES: The diagnostic performance of the FIB-4 and NFS at the current cutoff for advanced hepatic fibrosis in lean (body mass index [BMI] below 23 [calculated as weight in kilograms divided by height in meters squared]) and nonlean (BMI above 23) patients were evaluated. RESULTS: A total of 1501 patients were included in analysis (mean [SD] age, 46.1 [16.4] years); 788 male (52.5%), 115 lean (7.7%), 472 (30.2%) Korean, 821 (48.7%) Japanese, and 341 (21.3%) Taiwanese. Among the age- and sex-matched cohort, the mean (SD) age was 52.3 (15.1) years and 41.2% (47 of 114) were male. The diagnostic performance and areas under the operating characteristic curve of the FIB-4 (lean, 0.807 vs nonlean, 0.743; P = .28) and NFS (lean, 0.790 vs nonlean, 0.755; P = .54) between the 2 groups were comparable in the age- and sex-matched cohort. The sensitivity and specificity of the NFS showed increasing and decreasing tendency according to the BMI quartiles (P for trend < .001), while those of the FIB-4 did not (P for trend = .05 and P = .20, respectively). Additionally, although the areas under the operating characteristic curve of the FIB-4 and NFS were not significantly different in the lean group (0.807 vs 0.790; P = .09), the sensitivity of the current NFS cutoff values was lower in the lean group than in that of FIB-4 (54.4% vs 81.8%; P = .03). CONCLUSIONS AND RELEVANCE: In this cohort study, the performance of the FIB-4 and NFS in diagnosing advanced fibrosis did not differ significantly between the 2 groups overall. However, in lean NAFLD, while the sensitivity for diagnosing advanced hepatic fibrosis remained reasonable at the current cutoff level, the sensitivity of NFS at the current cutoff was too low to be an adequate screening tool.

Diagnostic Performance of Noninvasive Tests for Advanced Hepatic Fibrosis in Young Age Population.

BACKGROUND & AIMS: Most noninvasive tests (NITs) for hepatic fibrosis are designed for middle-aged patients with chronic liver disease. We compared the diagnostic performance of major NITs (aspartate aminotransferase-to-platelet ratio index [APRI], Fibrosis-4 index, and nonalcoholic fatty liver disease fibrosis score) for a community-based cohort. METHODS: This cross-sectional study analyzed 8775 participants who underwent magnetic resonance elastography at community health check-up centers. Advanced hepatic fibrosis (≥F3) was defined by magnetic resonance elastography thresholds of 3.6 kPa. The diagnostic performance of 3 NITs was evaluated according to the etiology of liver disease, sex, metabolic syndrome, obesity, and increased aminotransferase levels in 4 age groups. RESULTS: The APRI generally showed the best area under the receiver operating characteristic curve in patients aged 45 years or younger, and it was statistically significant in patients with chronic viral hepatitis and alcoholic fatty liver disease (P < .043). The best APRI cut-off value for detecting advanced hepatic fibrosis was 0.4, with a sensitivity and specificity of 75.8% and 73.5%, respectively, in the community-based cohort. The APRI showed balanced sensitivity and specificity across all age groups, whereas the other metrics showed low sensitivity in those aged <45 and low specificity in those >65 years. CONCLUSIONS: The APRI showed better sensitivity and negative predictive value than the Fibrosis-4 index and the nonalcoholic fatty liver disease fibrosis score in community-based populations with mixed etiology, and, thus, can be performed as the primary test in young adults (age, ≤45 y).

Nomenclature Dilemma of Metabolic Associated Fatty Liver Disease (MAFLD): Considerable Proportions of MAFLD Are Metabolic Healthy.

BACKGROUND & AIMS: The purpose of this study was to investigate the proportion of subjects with metabolic dysfunction-associated fatty liver disease (MAFLD) and to assess the degree of hepatic fibrosis and cardiovascular risk in metabolically healthy MAFLD subjects. METHODS: A total of 6740 subjects who underwent both magnetic resonance elastography and abdominal ultrasound were included in this study. Significant (≥3.0 kPa) and advanced (≥3.6 kPa) hepatic fibrosis were evaluated by magnetic resonance elastography. The metabolic unhealthy status among subjects with MAFLD was defined as the presence of diabetes or 2 or more metabolic risk abnormalities. RESULTS: The prevalence of MAFLD among the health examination cohort was 44.5% (3002 of 6740). A total of 26.6% (800 of 3002) of MAFLD subjects were metabolically healthy (≤1 risk factors and no diabetes), and 56.3% of MAFLD subjects (1691 of 3002) did not have metabolic syndrome. Hepatic fibrosis burden and cardiovascular risk were significantly higher in the metabolic unhealthy MAFLD group than in the healthy control group. However, the prevalence of significant (5.8% vs 4.3%; P = .099) and advanced hepatic fibrosis (0.8% vs 0.7%; P = .934) did not differ between the metabolically healthy MAFLD and healthy control groups. The prevalence of carotid artery plaque in the metabolically healthy MAFLD (32.7% vs 30.7%; P = .453) group was not different from that in the healthy control group. CONCLUSIONS: Contrary to the definition of MAFLD, a non-negligible number of metabolically healthy individuals are included in the MAFLD group. The metabolic healthy MAFLD group showed a comparable fibrosis burden and prevalence of carotid artery plaque compared with the healthy control group.

Poor Diagnostic Efficacy of Noninvasive Tests for Advanced Fibrosis in Obese or Younger Than 60 Diabetic NAFLD patients.

BACKGROUND & AIMS: Serum-based noninvasive tests (NITs) have been widely used to assess liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). However, the diagnostic efficacy of NITs across ranges of age, body mass index (BMI), and presence of type 2 diabetes (T2DM) may vary and have not been well-characterized. METHODS: We analyzed 1489 patients with biopsy-proven NAFLD from 6 centers in Japan, Taiwan, and Korea. Using histology as the gold standard, we compared the areas under the receiver operating characteristic (AUROCs) of Fibrosis-4 index (FIB-4), NAFLD fibrosis score (NFS), and the new Hepamet fibrosis score (HFS), with a focus on performance in subgroups as stratified by age, BMI, and the presence of T2DM. RESULTS: By histology, 44.0% of the overall cohort (655/1489) had F2-4, and 20.6% (307/1489) had F3-4 fibrosis. FIB-4 had the highest AUROCs for both F2-4 (0.701 vs NFS 0.676 and HFS 0.682, P = .001) and F3-4 (0.767 vs NFS 0.736 and HFS 0.752, P = .002). However, for F3-4 fibrosis, the AUROCs of all 3 NITs were generally higher in older (>60 years), nonobese (BMI <25 kg/m2), and non-diabetic patients, although overall the best performance was observed with FIB-4 among nonobese (BMI<25) diabetic patients (AUROC, 0.92). The worst performance was observed in younger patients with T2DM for all NITs including FIB-4 (AUROC, 0.63-0.66). CONCLUSIONS: FIB-4 had higher diagnostic efficacy for F3-4 than NFS or HFS, but this varied greatly by age, BMI, and T2DM, with better performance in older, nonobese, and nondiabetic patients. However, all NITs including FIB-4 had unacceptably poor performance in young or obese diabetic patients.

Reappraisal of fibrosis-4 index and non-alcoholic fatty liver disease fibrosis score for advanced fibrosis in average-risk population.

Background and aim: The current cut-offs for fibrosis-4 (FIB-4) and non-alcoholic fatty liver disease fibrosis score (NFS) are suboptimal for screening because of low accuracy and high false-negative rates in average-risk populations. This study aimed to reappraisal the performance of FIB-4 and NFS in such average-risk populations. Methods: This is a cross-sectional study, which retrospectively reviewed the magnetic resonance elastography (MRE) data of 8,522 subjects. Individuals with history of significant alcohol consumption and those with positive viral serologic markers were excluded. Finally, 6,215 average-risk individuals were analyzed. Results: The area under the receiver operating characteristic curves (AUROCs) of FIB-4 for the diagnosis of advanced hepatic fibrosis was higher than that in the NFS especially in the metabolically healthy. The AUROCs of FIB-4 for in the average-risk population was also higher than that in the NFS (0.840 in FIB-4 vs. 0.798, P = 0.036). However, the sensitivity of FIB-4 and NFS was low (69.6 and 61.4%, respectively) in applying the current cut-off of FIB-4 [1.3 (2.0)] and NFS [-1.455 (0.12)]. At cut-off of FIB-4 at 1.0, sensitivity (90.2%), and negative predictive value (99.7%) were improved. Conclusion: The diagnostic performance of FIB-4 was better than that of NFS for screening hepatic fibrosis in average-risk populations. It is recommended to use FIB-4 rather than NFS, when screening for hepatic fibrosis in general population.

Selecting the Target Population for Screening of Hepatic Fibrosis in Primary Care Centers in Korea.

Screening strategies for hepatic fibrosis are heavily focused on patients with fatty liver on sonography in primary care centers. This study aimed to investigate the target population for screening significant hepatic fibrosis in primary care centers. This retrospective cross-sectional cohort study used data from 13 nationwide centers. A total of 5111 subjects who underwent both abdominal sonography and magnetic resonance elastography as part of their health check-up were included. Subjects with viral hepatitis and/or a history of significant alcohol consumption were excluded. Significant and advanced hepatic fibrosis was defined as ≥3.0 kPa and ≥3.6 kPa in the MRE test, respectively. The prevalence of significant and advanced hepatic fibrosis was 7.3% and 1.9%, respectively. Among the subjects with significant hepatic fibrosis, 41.3% did not have fatty liver. Hepatic fibrosis burden increased according to the number of metabolic risk abnormalities. Nearly 70% of subjects with significant hepatic fibrosis also had two or more metabolic risk abnormalities and/or diabetes. However, the prevalence of fibrosis did not differ between the groups with and without fatty liver. The presence of two or more metabolic risk abnormalities was an independent risk factor for significant hepatic fibrosis regardless of the fatty liver. Therefore, in the setting of primary care centers, screening for hepatic fibrosis would better be extended to subjects with metabolically unhealthy status beyond those with fatty liver.

Prevalence of advanced hepatic fibrosis and comorbidity in metabolic dysfunction-associated fatty liver disease in Korea.

BACKGROUND & AIMS: There are several reports on the prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD). However, the prevalence of advanced hepatic fibrosis in MAFLD is largely unknown. We aimed to evaluate the prevalence of advanced fibrosis in MAFLD. METHODS: A total of 6775 subjects from nationwide 13 health check-up centres were included in this cross-sectional study. Fatty liver was evaluated using ultrasonography. Significant (≥F2) and advanced (≥F3) hepatic fibrosis were defined by MRE thresholds of 3.0 kPa (range: 2.99-3.65 kPa) and 3.6 kPa (range: 3.4-3.9 kPa) respectively. The sex- and age-standardized prevalence of MAFLD and hepatic fibrosis was estimated. RESULTS: The sex- and age-standardized prevalence of MAFLD was 33.9%. The prevalence of obesity (BMI ≥25 kg/m2 ) in MAFLD was 71.1%, and 79.0% of obese subjects had MAFLD. The prevalence of diabetes in MAFLD was 13.3%, and 73.6% of subjects with diabetes had MAFLD. The sex- and age-standardized prevalence of significant (≥F2) and advanced hepatic fibrosis (≥F3) amongst MAFLD was 9.7% (range: 3.0-9.8%) and 3.0% (range: 2.6-4.6%) respectively. The prevalence of advanced hepatic fibrosis in overweight/obese (group I), lean (group II) and diabetic (group III) MAFLD was 2.3%, 3.1% and 9.5% respectively. CONCLUSION: The sex- and age-standardized prevalence of advanced fibrosis was 3.0% (range: 2.6-4.6%) in subjects with MAFLD.

Association between serum uric acid level and non-alcoholic fatty liver disease in Koreans.

Background: The association between serum uric acid (SUA) levels and non-alcoholic fatty liver disease (NAFLD) is controversial. Objectives: We compared the association of SUA levels with NAFLD, abnormal alanine transferase (ALT), and the degree of liver fibrosis to clarify the association of SUA levels with NAFLD. Methods: We conducted a retrospective cross-sectional study. Adult patients who underwent a health check-up (N = 1,343) were included for analysis. Fatty liver was diagnosed by abdominal ultrasonography. The degree of liver fibrosis was determined using the NAFLD fibrosis score (NFS). Pearson correlation analysis showed a stronger correlation of SUA level with the fatty liver index (r = 0.40, P < 0.001) than the correlation with serum ALT level (r = 0.28, P < 0.001), or NFS (r = 0.018, P = 0.51). SUA levels in patients with NAFLD and an abnormal liver function test (LFT) result were significantly higher than levels in patients without NAFLD and abnormal LFT results. By contrast, there was no significant association of SUA level with NFS grade. When age, male sex, body mass index, the presence of hypertension, diabetic mellitus, and NAFLD, abnormality of ALT level, and SUA level were included in binary logistic regression to evaluate risk factors for elevated NFS grade, hyperuricemia was not significantly associated with NFS grade (OR = 0.94, P = 0.75). Conclusion: Pearson correlation and logistic regression together indicated SUA level is more closely associated with hepatic steatosis than abnormal liver function test or hepatic fibrosis.

Comparison of diagnostic performance between FIB-4 and NFS in metabolic-associated fatty liver disease era.

AIMS: Fibrosis-4 index (FIB-4) and non-alcoholic fatty liver disease (NAFLD) fibrosis score (NFS) are the two most widely used non-invasive tools for screening of advanced fibrosis in subjects with NAFLD. Since metabolic dysfunction-associated fatty liver disease (MAFLD) has been proposed as a new category of fatty liver disease, we aimed to compare the diagnostic performance of FIB-4 and NFS in subjects with MAFLD and in various subgroups. METHODS: This study was designed as cross-sectional study. Data from 6775 subjects who underwent magnetic resonance elastography (MRE) and abdominal ultrasonography at the same time during a health check-up at 13 various health check-up centers were retrospectively reviewed. Advanced fibrosis was defined as an MRE value of ≥3.6 kPa. RESULTS: The area under the receiver operating characteristic curves (AUROCs) of FIB-4 and NFS for diagnosing advanced fibrosis were similar in subjects with MAFLD. However, the AUROC of NFS was lower than that of FIB-4 in the diabetic subgroup of MAFLD (0.809 in FIB-4 vs. 0.717 in NFS, p = 0.002). The performances of both FIB-4 and NFS were poor in the subgroup of MAFLD with significant alcohol intake. CONCLUSIONS: The overall diagnostic performance of FIB-4 and NFS for diagnosing advanced fibrosis did not differ among subjects with MAFLD. However, the performance of NFS was lower in the diabetes subgroup of MAFLD. The diagnostic performance of FIB-4 was better for fibrosis in various subgroups of MAFLD.

Fibrosis Burden of Missed and Added Populations According to the New Definition of Metabolic Dysfunction-Associated Fatty Liver.

Recently, the classification of fatty liver and the definition for non-alcoholic fatty liver disease (NAFLD) have been challenged. Herein, we aim to evaluate the burden of hepatic fibrosis in the missed and added populations following the proposal of the new definition of metabolic dysfunction-associated fatty liver (MAFLD) in a health check-up cohort. A total of 6775 subjects underwent both magnetic resonance elastography (MRE) and an abdominal ultrasound at 13 nationwide health check-up centers in Korea. Significant and advanced hepatic fibrosis was defined as ≥3.0 kPa and ≥3.6 kPa in the MRE test, respectively. The prevalence of sonographic fatty liver (FL) was 47.4%. Among the subjects with sonographic FL, 77.3% and 94% are compatible with NAFLD and with the new MAFLD definitions, respectively. Moreover, 72% of FL cases belong to both the NAFLD and MAFLD definitions, whereas 1.4% is compatible with neither. The population compatible with the MAFLD definition has the following coexisting liver diseases: alcohol-related (71.9%), hepatitis B (23.9%), hepatitis C (0.4%), and both alcohol and viral hepatitis (2.8%). The prevalence of significant and advanced hepatic fibrosis is considerable in the MAFLD-only group. However, the prevalence of significant and advanced hepatic fibrosis is similar in the NAFLD-only group, and neither the NAFLD nor MAFLD group compared to healthy controls. The added population (MAFLD-only group), according to the new MAFLD definition, has a higher metabolic and fibrosis burden when compared to those in the missed population (NAFLD-only group).