Prevalence and severity of nonalcoholic fatty liver disease by transient elastography: Genetic and metabolic risk factors in a general population

Breakthrough in the Treatment of Metabolic Associated Steatotic Liver Disease: Is it all over?

On March 14, 2024, after more than 25 years of intense research and a long series of failures, the Food and Drug Administration approved resmetirom as first drug for the treatment of non-alcoholic steatohepatitis (NASH) with fibrosis (now Metabolic-Associated Steatotic Liver Disease - MASLD). The present review covers this difficult process, finally providing a drug to complement lifestyle intervention, that has long been the sole approved therapeutic intervention. However, the availability of a drug shown to reduce disease progression in advanced stages of diseases opens a series of questions that deserve even more intense research. How to continue ongoing trials? How to generate an appropriate use of resmetirom in the community, limiting treatment according to predefined criteria and according to individual risk assessment? How to guarantee that both hepatic and non-hepatic comorbidities are appropriately targeted? How to define cost-effective strategies that might prevent the generation of unacceptable differences within the population, given the high costs of novel drugs and the extremely high numbers of candidates to treatment? Only a close surveillance of drug use in the real world, generated by insurance databases and national healthcare system registries, might provide adequate answers to these compelling questions.

NLRP3 inflammasome pathway involved in the pathogenesis of metabolic associated fatty liver disease

The prevalence of Metabolic-associated fatty liver disease (MAFLD) has been steadily increasing worldwide, paralleling the global epidemic of obesity and diabetes. It is estimated that approximately one-quarter of the global population is affected by MAFLD. Despite its high prevalence, MAFLD often goes undiagnosed due to the lack of specific symptoms in its early stages. However, as the disease progresses, it can lead to more severe liver-related complications such as fibrosis, cirrhosis, and hepatocellular carcinoma. Therefore, we aimed to investigate the expression levels of the nucleotide-binding oligomerization domain, leucine-rich repeat (LRR)-containing proteins (NLR) family pyrin domain-containing protein 3 [NLRP3] inflammasome pathway components, NLRP3 and interleukin 1β (IL-1β) genes in patients with MAFLD with various degrees of steatosis and fibrosis. Participants were classified into two equal groups; MAFLD group: consisted of 120 patients with different degrees of hepatic fibrosis and steatosis based on fibro scan results. The non-MAFLD group was comprised of 107 participants. Molecular analysis of pyrin domain-containing protein 3 and IL-1β relative gene expressions was performed in the blood of all participants, using Real-time quantitative polymerase chain reaction (RT-qPCR). Patients with post-MAFLD hepatic fibrosis had significantly higher relative gene expression levels of IL-1β and NLRP3; with IL-1β > 1.1 had AUC of 0.919, sensitivity of 88.33, specificity of 96.26, PPV of 96.4, and NPV of 88 and 92.3 accuracy (p value < 0.001). NLRP3 > 1.33 had a sensitivity of 97.5, specificity of 99.07, PPV of 99.2, NPV of 97.2, and 98.3 accuracy with an AUC of 0.991 (p value < 0.001) as predictors of post-MAFLD hepatic fibrosis.. A significant increase in the mean relative gene expression levels of both IL-1β and NLRP3 found in patients with early fibrosis (F0-F1-2); 31.97 ± 11.8 and 6.76 ± 2.18, respectively; compared with patients with advanced hepatic fibrosis stages (F2-F3); 2.62 ± 3.71 and 4.27 ± 2.99 (p < 0.001 each). The present study provides novel evidence for the possible involvement of IL-1β and NLRP3 inflammasome in metabolic-associated fatty liver disease pathogenesis and could be valid markers for the early detection of post-MAFLD hepatic fibrosis.

Correlation between controlled attenuation parameter values with SYNTAX score in patients with significant coronary artery disease

Non-alcoholic fatty liver disease (NAFLD) is an emerging cause of chronic liver disease, with coronary artery disease (CAD) as the main cause of death in NAFLD patients. However, correlation between the severity of liver steatosis and coronary atherosclerosis is yet to be understood. Here we aim to explore the correlation between controlled attenuation parameter (CAP) values and SYNTAX (Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) score in adult patients with significant CAD, defined as ≥ 50% stenosis of the left main coronary artery, or ≥ 70% stenosis of the other major coronary arteries. A cross-sectional study was conducted on 124 adult patients with significant CAD who underwent coronary angiography. Transient elastography with CAP was used to assess liver steatosis severity, resulting in a mean CAP value of 256.5 ± 47.3 dB/m, with 52.5% subjects had significant steatosis (CAP value of ≥ 248 dB/m). Median SYNTAX score was 22. A statistically significant correlation was observed between CAP value and SYNTAX score (r = 0.245, p < 0.0001). The correlation was more pronounced in patients with prior history of PCI (r = 0.389, p = 0.037). Patients with high-risk SYNTAX score (> 32) had the highest CAP value (285.4 ± 42.6 dB/m), and it was significantly higher than those with low-risk SYNTAX score (0-22), with a mean difference of 38.76 dB/m (p = 0.006). Patients with significant liver steatosis should undergo periodic CAD assessment and lifestyle modification, especially those with severe liver steatosis.

The prevalence and predictors of metabolic dysfunction-associated steatotic liver disease and fibrosis/cirrhosis among adolescents/young adults

OBJECTIVES

We investigated the current prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and fibrosis/cirrhosis and identified at-risk populations for MASLD and MASLD-related fibrosis among US adolescents and young adults in the United States.

METHODS

Utilizing the National Health and Nutrition Examination Survey 2017-2020, the prevalence of MASLD and fibrosis/cirrhosis was assessed via controlled attenuation parameter (CAP) score and liver stiffness measurements by transient elastography in participants aged 12-29 years with at least one cardiometabolic criteria and absence of other chronic liver disease. Multivariable logistic regression was performed to determine predictors of MASLD and MASLD-related fibrosis.

RESULTS

The overall prevalence of MASLD was 23.9% (95% confidence interval [CI]: 21.3-26.5 for CAP ≥ 263 dB/m) and 17.3% (95% CI: 14.7-20.0 for ≥285 dB/m), respectively. The prevalence of fibrosis and cirrhosis in MASLD was 11.0% and 3.1%, respectively. When categorized by age, the prevalence of MASLD varied from 16.8% (of which 6.2% [fibrosis], 1.8% [cirrhosis]) in early and middle adolescents (12-17 years), to 25.5% (11.8% [fibrosis], 4.8% [cirrhosis]) in late adolescents and young adults (18-24 years), and to 30.4% (of which 13.2% [fibrosis] and 2.1% [cirrhosis]) in older young adults (25-29 years). The independent predictors for MASLD included male sex, Hispanic, non-Hispanic Asian, body mass index, and low HDL-cholesterol. In contrast, diabetes and body mass index were associated with an increased risk of fibrosis in individuals with MASLD.

CONCLUSIONS

The prevalence of MASLD and related fibrosis in adolescents and young adults in the United States has reached a significant level, with a substantial proportion of cirrhosis.

Factors associated with body weight gain and insulin-resistance: a longitudinal study

BACKGROUND

Obesity is the result of energy intake (EI) chronically exceeding energy expenditure. However, the potential metabolic factors, including insulin resistance, remain unclear. This study longitudinally investigated factors associated with changes in body weight.

SUBJECTS

A cohort of 707 adults without diabetes were investigated at the 4-year follow-up visit. The habitual intake of energy and macronutrients during the past 12 months was assessed using a validated Food Frequency Questionnaire for the local population. Homeostatic model assessment of β-cell function and insulin resistance (HOMA-IR) was used as a surrogate measure of insulin resistance. Additionally, PNPLA3 was genotyped.

RESULTS

Eighty-seven participants were weight gainers (G; cutoff value = 5 kg), and 620 were non-gainers (NG). Initial anthropometric (G vs. NG: age, 44 ± 13 vs 51 ± 13 years, P < 0.001; body mass index, 27.8 ± 6.5 vs 28.1 ± 5.1 kg/m2, P = ns; body weight, 76.7 ± 22.1 vs 74.2 ± 14.7 kg, P = ns; final body weight, 86.3 ± 23.7 vs 72.9 ± 14.2 kg, P < 0.001) and diet characteristics, as well as insulin concentrations and HOMA-IR values, were similar in both groups. Four years later, G showed significantly increased EI, insulin concentrations, and HOMA-IR values. G had a higher prevalence of the PNPLA3 CG and GG alleles than NG (P < 0.05). The presence of G was independently associated with age (OR = 1.031), EI change (OR = 2.257), and unfavorable alleles of PNPLA3 gene (OR = 1.700). Final body mass index, waist circumference, and EI were independently associated with final HOMA-IR (P < 0.001).

CONCLUSIONS

EI is associated with body weight gain, and genetic factors may influence the energy balance. Insulin resistance is a consequence of weight gain, suggesting a possible intracellular protective mechanism against substrate overflow.

CLINICAL TRIAL REGISTRATION

ISRCTN15840340.

Oral Supplementation of Phosphatidylcholine Attenuates the Onset of a Diet-Induced Metabolic Dysfunction-Associated Steatohepatitis in Female C57BL/6J Mice

BACKGROUND & AIMS

Changes in phosphatidylcholine levels in the liver have been associated with the development of metabolic dysfunction-associated steatotic liver disease. Here, the effects of supplementing phosphatidylcholine on the development of early signs of metabolic dysfunction-associated steatohepatitis were assessed.

METHODS

Male and female C57BL/6J mice were fed a liquid control or a fructose-, fat-, and/or cholesterol-rich diet for 7 or 8 weeks. The diets of female mice were fortified ± phosphatidylcholine (12.5 mg/g diet). In liver tissue and portal blood, indices of liver damage, inflammation, and bacterial endotoxemia were measured. J774A.1 cells and human monocytes preincubated with phosphatidylcholine (0.38 mmol/L) were challenged with lipopolysaccharide (50-100 ng/mL) ± the peroxisome proliferator-activated receptor γ (PPARγ) activator pioglitazone (10 μmol/L) or ± a liver receptor homolog 1 (LRH-1) antagonist 1-(3'-[1-(2-[4-morpholinyl]ethyl)-1H-pyrazol-3-yl]-3-biphenylyl)ethanon (1-10 μmol/L).

RESULTS

In fructose-, fat-, and/or cholesterol-rich diet-fed mice the development of fatty liver and the beginning of inflammation were associated with significantly lower hepatic phosphatidylcholine levels when compared with controls. Supplementing phosphatidylcholine significantly attenuated the development of fatty liver and inflammation, being associated with protection against the induction of PPARγ2, and activation of nuclear factor of κ light polypeptide gene enhancer in B-cell inhibitor α whereas Lrh1 expression was unchanged. The protective effects of phosphatidylcholine on the lipopolysaccharide-induced activation of J774A.1 cells and human monocytes were attenuated significantly by the PPARγ activator pioglitazone and the LRH-1 antagonist.

CONCLUSIONS

Our data suggest that phosphatidylcholine levels in the liver are lower in early metabolic dysfunction-associated steatohepatitis in mice and that supplementation of phosphatidylcholine can diminish the development of metabolic dysfunction-associated steatotic liver disease through mechanisms involving LRH-1/PPARγ2/ nuclear factor κ-light-chain enhancer of activated B-cell signaling.

Country-Wide HCV Elimination Strategies Need to Reach Older Patients in the General Population: The Italian Experience

HCV infection is still a major burden worldwide, and most countries are not on track to meet the WHO 2030 elimination goal. The current challenge is to identify individuals to be treated. In this study, we will describe the trend of new DAA prescriptions and the changes over time in terms of the characteristics of patients starting antiviral therapy in our unit. Data of 1646 hepatitis C patients who started therapy during the period of 2015-2022 regarding annual number of prescriptions, age, gender, nationality, HCV genotype, provenance, and liver disease severity were analyzed. We observed a peak in the number of new prescriptions in 2018 and a downward trend starting in 2019. Patients from the general population, centers for addictions, and prison differed significantly. The mean age in the general population remained above 60 years, the percentage of patients from centers for addictions and prison increased and, after 2016, there was no significant change in the percentage of patients with F3-F4 fibrosis. As HCV screening and linkage-to-care pathways seem to be already well implemented and successful in centers for addictions and in prisons, efforts need to be focused on those of older age in the general population. To carry this out, the more structured involvement of different health professionals must be figured out.

Geographical similarity and differences in the burden and genetic predisposition of NAFLD

NAFLD has become a major public health problem for more than 2 decades with a growing prevalence in parallel with the epidemic of obesity and type 2 diabetes (T2D). The disease burden of NAFLD differs across geographical regions and ethnicities. Variations in prevalence of metabolic diseases, extent of urban-rural divide, dietary habits, lifestyles, and the prevalence of NAFLD risk and protective alleles can contribute to such differences. The rise in NAFLD has led to a remarkable increase in the number of cases of cirrhosis, hepatocellular carcinoma, hepatic decompensation, and liver-related mortality related to NAFLD. Moreover, NAFLD is associated with multiple extrahepatic manifestations. Most of them are risk factors for the progression of liver fibrosis and thus worsen the prognosis of NAFLD. All these comorbidities and complications affect the quality of life in subjects with NAFLD. Given the huge and growing size of the population with NAFLD, it is expected that patients, healthcare systems, and the economy will suffer from the ongoing burden related to NAFLD. In this review, we examine the disease burden of NAFLD across geographical areas and ethnicities, together with the distribution of some well-known genetic variants for NAFLD. We also describe some special populations including patients with T2D, lean patients, the pediatric population, and patients with concomitant liver diseases. We discuss extrahepatic outcomes, patient-reported outcomes, and economic burden related to NAFLD.

High prevalence of liver fibrosis among general population: a Romanian population-based study

BACKGROUND

Cirrhosis can be present undected for years prior to a symptomatic presentation. Early detection may result in improved outcomes. Data are lacking, however, regarding the yield of screening in many populations. We aimed to determined prevalence of significant liver fibrosis diagnosed by vibration-controlled transient elastography (VCTE) in apparently healthy Romanians.

METHODS

Between December 2021 and March 2022, we prospectively screened 1,027 subjects from different counties of Northeastern Romania using VCTE and B-mode ultrasonagraphy after a comprehensive medical history questionnaire. Participants with abnormal liver stiffness measurement values were further evaluated by laboratory tests to identify the severity and etiology of chronic liver disease.

RESULTS

Overall, 17.9% of subjects had liver stiffness measurments (LSM) ≥8 kpa, including 55 with LSM ≥13.0 kpa. Among these subjects, 26.1% had a history of heavy alcohol intake, 22.3% tested positive for hepatitis B and/or C infection, and 49.5% were diagnosed with NAFLD. The prevalence of elevated LSM was highest among older subjects (>60 y old) and those with diabetes. Among those with LSM ≥13 kPa and ≥9.6 kpa, FIB-4 was <2.67 in 46.9% and 87.5% respectively.

CONCLUSION

There is high prevalence of significant liver fibrosis in the Romanian general population. VCTE is a usefool tool for early detection of liver disease and appears more sensitive than FIB-4.

Factors Associated with Liver Fibrosis in Chinese Patients with Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease

Purpose

Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are frequently co-occurring diseases. Liver fibrosis (LF), with increasing incidence, has a prognostic value for NAFLD mortality. Our study aimed to investigate the relevant factors for FL in T2DM individuals with NAFLD.

Patients and Methods

A total of 565 T2DM patients with NAFLD from Hebei General Hospital participated in the study. Patients underwent an abdominal ultrasound, a questionnaire and laboratory tests. The fibrosis-4 index (FIB-4) was used to evaluate LF, with FIB ≥1.3 indicating LF and FIB ≥2.67 indicating F3-4 fibrosis.

Results

Compared with NLF group, LF group had higher levels of systolic blood pressure (SBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transpeptidase (GGT). The glomerular filtration rate (GFR), low-density lipoprotein cholesterol (LDL), glycated hemoglobin (HbA1c), and platelets (PLT) in LF patients were lower than those without LF. Patients with LF were older than those without LF. ALT, AST, and GGT in patients with severe LF were higher than those with mild LF, while platelet was lower. Age, SBP, duration of diabetes, ALT, AST, and GGT were positively correlated with FIB-4, while eGFR, TC, LDL, and HbA1c were negatively correlated with FIB-4. Logistic regression showed that age, SBP, ALT, GGT, LDL, and PLT were independently associated with LF.

Conclusion

For T2DM patients combined with NAFLD, older age, higher SBP, higher ALT, higher GGT, lower LDL, and lower PLT were relevant factors for LF.

MAFLD: a multisystem disease

Nonalcoholic fatty liver disease (NAFLD), affecting about 25% of general population and more than 50% of dysmetabolic patients, is an emerging cause of chronic liver disease and its complications. Recently, an international consensus of experts proposed to rename this disease as 'Metabolic dysfunction-Associated Fatty Liver Disease' (MAFLD) to focus on the bidirectional interplay between fatty liver and metabolic alterations and to stress the need of assessing fatty liver independently from alcohol consumption and other coexisting causes of liver disease. The peculiarity of NAFLD/MAFLD lies in the presence of a higher risk of not only - as expected - liver-related events but also of extrahepatic events, mostly cardiovascular and cancers. Available evidence suggests that these associations are not only the expression of sharing the same risk factors but shed light about the ability of NAFLD/MAFLD and particularly of its progressive form - nonalcoholic/metabolic dysfunction-associated steatohepatitis - to act as an independent risk factor via promotion of atherogenic dyslipidemia and a proinflammatory, profibrogenic, and procoagulant systemic environment. The present review summarizes available epidemiological and clinical evidence supporting the concept of NAFLD/MAFLD as a multisystemic disease, and highlights potential explanatory mechanisms underlying the association between NAFLD/MAFLD and extrahepatic disorders.

Screening for Liver Fibrosis in the General Population: Where Do We Stand in 2022?

Approximately 30% of the worldwide population has at least one risk factor for liver disease. Identifying advanced liver disease before the occurrence of complications remains a difficult challenge in clinical practice, where diagnosis comes too late for many patients, at the time of liver decompensation or palliative hepatocellular carcinoma, with poor short-term prognosis. Noninvasive, blood- or elastography-based tests of liver fibrosis (NITs) have been developed for the early diagnosis of advanced liver fibrosis. Recent population-based studies evaluating the screening of liver fibrosis with these NITs have provided important information on at-risk groups that should be targeted. New measures based on the sequential use of NITs help to better organize the referral of at-risk patients to the liver specialist. However, energizing these measures will require increased awareness of both chronic liver diseases and the use of NITs among non-specialists.

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.

Diagnostic and therapeutic potential of protease inhibition

Proteases are enzymes that hydrolyze peptide bonds in proteins and peptides; thus, they control virtually all biological processes. Our understanding of protease function has advanced considerably from nonselective digestive enzymes to highly specialized molecular scissors that orchestrate complex signaling networks through a limited proteolysis. The catalytic activity of proteases is tightly regulated at several levels, ranging from gene expression through trafficking and maturation to posttranslational modifications. However, when this delicate balance is disturbed, many diseases develop, including cancer, inflammatory disorders, diabetes, and neurodegenerative diseases. This new understanding of the role of proteases in pathologic physiology indicates that these enzymes represent excellent molecular targets for the development of therapeutic inhibitors, as well as for the design of chemical probes to visualize their redundant activity. Recently, numerous platform technologies have been developed to identify and optimize protease substrates and inhibitors, which were further used as lead structures for the development of chemical probes and therapeutic drugs. Due to this considerable success, the clinical potential of proteases in therapeutics and diagnostics is rapidly growing and is still not completely explored. Therefore, small molecules that can selectively target aberrant protease activity are emerging in diseases cells. In this review, we describe modern trends in the design of protease drugs as well as small molecule activity-based probes to visualize selected proteases in clinical settings.

Subclinical and clinical atherosclerosis in non-alcoholic fatty liver disease is associated with the presence of hypertension

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with increased cardiovascular (CV) risk. However, it is unclear whether NAFLD contributes independently to the development of CV disease. Our study aimed at assessing the differences in several indices of atherosclerosis, arterial stiffness and cardiac morphology among patients with isolated NAFLD, isolated hypertension (HT) or a combination of the two conditions.

METHODS AND RESULTS

A total of 169 participants (mean age = 50.4 ± 10.2 yrs; males = 73.6%) were divided according to the presence of NAFLD and HT into three groups: only NAFLD (55 patients), only HT (49 patients), and NAFLD + HT (65 patients). Exclusion criteria were a BMI≥35 kg/m² and a diagnosis of diabetes mellitus. Carotid ultrasonography was performed to measure markers of atherosclerosis and arterial stiffness. Cardiac remodeling was analyzed using echocardiography. The prevalence of subclinical and overt atherosclerosis was significantly higher in the NAFLD + HT patients as compared to the other two groups (atherosclerotic plaques: 43.1%, 10.9%, and 22.4% (p < 0.001) in NAFLD + HT, NAFLD, and HT groups, respectively). No differences were found among indices of arterial stiffening and cardiac remodeling across the three groups. In multivariate regression analysis, the coexistence of NAFLD and HT was an independent risk factor for overt atherosclerosis (OR = 4.88, CI 95% 1.14-20.93), while no association was found when either NAFLD or HT was considered alone.

CONCLUSION

Overt atherosclerosis was significantly present only in NAFLD + HT patients, but not in patients with isolated NAFLD. This implies that the impact of NAFLD on vascular structure and function could depend on the coexistence of other major CV risk factors, such as HT.

Prepandemic Prevalence Estimates of Fatty Liver Disease and Fibrosis Defined by Liver Elastography in the United States

BACKGROUND AND AIMS

Fatty liver disease is a growing public health burden. We estimated prepandemic fatty liver disease prevalence determined by transient elastography-assessed hepatic steatosis and fibrosis, and examined associations with lifestyle and other factors in a United States population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 7923 non-Hispanic white, non-Hispanic black, non-Hispanic Asian, and Hispanic men and women aged 20 years and over in the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020 prepandemic data.

RESULTS

The prevalence of fatty liver disease (CAP > 300 dB/m) was 28.8% and of fibrosis (liver stiffness > 8 kPa) was 10.4%. Only 7.2% of participants with fatty liver disease and 10.9% with fibrosis reported being told by a health care provider that they had liver disease. In addition to known risk factors such as metabolic factors and ALT, persons with fatty liver disease were less likely to meet physical activity guidelines, more likely to be sedentary for ≥ 12 h a day, and reported a less healthy diet. Persons with fibrosis were less likely to have a college degree and reported a less healthy diet.

CONCLUSIONS

In the U.S. population, most persons with fatty liver disease are unaware of their condition. Physical activity and dietary modifications might reduce the fatty liver disease burden. There is an urgent need for fatty liver disease management in high-risk individuals using transient elastography or other noninvasive methods to intervene in disease progression.

The prevalence and incidence of NAFLD worldwide: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide and the leading cause of liver-related morbidity and mortality. We aimed to predict the burden of NAFLD by examining and estimating the temporal trends of its worldwide prevalence and incidence.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, EMBASE, Scopus, and Web of Science without language restrictions for reports published between date of database inception and May 25, 2021. We included observational cross-sectional or longitudinal studies done in study populations representative of the general adult population, in whom NAFLD was diagnosed using an imaging method in the absence of excessive alcohol consumption and viral hepatitis. Studies were excluded if conducted in paediatric populations (aged <18 years) or subgroups of the general population. Summary estimates were extracted from included reports by KR and independently verified by HA using the population, intervention, comparison, and outcomes framework. Primary outcomes were the prevalence and incidence of NAFLD. A random-effects meta-analysis was used to calculate overall and sex-specific pooled effect estimates and 95% CIs.

FINDINGS

The search identified 28 557 records, of which 13 577 records were screened; 299 records were also identified via other methods. In total, 72 publications with a sample population of 1 030 160 individuals from 17 countries were included in the prevalence analysis, and 16 publications with a sample population of 381 765 individuals from five countries were included in the incidence analysis. The overall prevalence of NAFLD worldwide was estimated to be 32·4% (95% CI 29·9-34·9). Prevalence increased significantly over time, from 25·5% (20·1-31·0) in or before 2005 to 37·8% (32·4-43·3) in 2016 or later (p=0·013). Overall prevalence of NAFLD was significantly higher in men than in women (39·7% [36·6-42·8] vs 25·6% [22·3-28·8]; p<0·0001). The overall incidence of NAFLD was estimated to be 46·9 cases per 1000 person-years (36·4-57·5); 70·8 cases per 1000 person-years (48·7-92·8) in men and 29·6 cases per 1000 person-years (20·2-38·9) in women (p<0·0001). There was considerable heterogeneity between studies of both NAFLD prevalence (I²=99·9%) and NAFLD incidence (I²=99·9%).

INTERPRETATION

Worldwide prevalence of NAFLD is considerably higher than previously estimated and is continuing to increase at an alarming rate. Incidence and prevalence of NAFLD are significantly higher among men than among women. Greater awareness of NAFLD and the development of cost-effective risk stratification strategies are warranted to address the growing burden of NAFLD.

FUNDING

Canadian Institutes of Health.

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.

GW9662, a peroxisome proliferator-activated receptor gamma antagonist, attenuates the development of non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Insulin resistance is among the key risk factors for the development of non-alcoholic fatty liver disease (NAFLD). Recently, it has been reported that GW9662, shown to be a potent peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, may improve insulin sensitivity in settings of type 2 diabetes. Here, we determined the effects of GW9662 on the development of NAFLD and molecular mechanisms involved.

METHODS

Female C57BL/6J mice were pair-fed either a liquid control diet (C) or a fat-, fructose- and cholesterol-rich diet (FFC) for 8 weeks while either being treated with GW9662 (1 mg/kg body weight; C+GW9662 and FFC+GW9662) or vehicle (C and FFC) i.p. three times weekly. Indices of liver damage and inflammation, parameters of glucose metabolism and portal endotoxin levels were determined. Lipopolysaccharide (LPS)-challenged J774A.1 cells were treated with 10 μM GW9662.

RESULTS

Despite similar caloric intake the development of NAFLD and insulin resistance were significantly attenuated in FFC+GW9662-treated mice when compared to FFC-fed animals. Bacterial endotoxin levels in portal plasma were almost similarly increased in both FFC-fed groups while expressions of toll-like receptor 4 (Tlr4), myeloid differentiation primary response 88 (Myd88) and interleukin 1 beta (Il1b) as well as nitrite (NO₂^-) concentration in liver were significantly higher in FFC-fed mice than in FFC+GW9662-treated animals. In J774A.1 cells, treatment with GW9662 significantly attenuated LPS-induced expression of Il1b, interleukin 6 (Il6) and inducible nitric oxide synthase (iNos) as well as NO₂^- formation.

CONCLUSION

In summary, our data suggest that the PPARγ antagonist GW9662 attenuates the development of a diet-induced NAFLD and that this is associated with a protection against the activation of the TLR4 signaling cascade.

The prevalence of alcoholic and nonalcoholic fatty liver disease in adolescents and young adults in the United States: analysis of the NHANES database

BACKGROUND

The prevalence of fatty liver disease is potentially increasing in adolescents and young adults (AYAs) due to the obesity and alcohol pandemics. The aim of this study was to assess the prevalence of alcohol-associated fatty liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) in a representative U.S. cohort utilizing transient elastography to directly measure hepatic steatosis and suspected fibrosis.

METHODS

AYAs (age 15-39 years) with valid FibroScan® measurements in the National Health and Nutrition Examination Survey (NHANES) database (2017-2018) were included in the analyses. Those with viral hepatitis, pregnancy, or ALT/AST > 500 U/L were excluded. The population was divided into those with excessive alcohol consumption (ALQ130) and those without. Controlled attenuation parameter (CAP) score ≥ 248 dB/m was used to identify suspected ALD and NAFLD. In those with evidence of ALD, the following cutoffs of liver stiffness measurement (LSM) were used for suspected fibrosis: F ≥ F2 at LSM ≥ 7.5 kPa and F ≥ F3 at ≥ 9.5 kPa, respectively. In those with suspected NAFLD, the following LSM cutoffs were used: F ≥ F2 at 6.1 and F ≥ F3 at ≥ 7.1, respectively. Cutoffs were chosen based on published literature to maximize sensitivity.

RESULTS

Comparing to those without, subjects with excessive alcohol consumption tended to be older (29.8 vs 28.5 years), have a higher BMI (29.3 vs 28.9 kg/m2), and be from a White ethnicity (65.3% vs. 55.4%). In subjects with excessive alcohol consumption, suspected ALD was present in 56.59% (95% CI 41.57-70.49). In those with suspected ALD, suspected significant fibrosis (F ≥ F2) was present in 12.3% (95% CI 4.74-28.34) and advanced fibrosis (F ≥ F3) was present in 6.31% (95% CI 0.69-39.55). Similarly, in subjects without excessive alcohol consumption, suspected NAFLD was present in 40.04% (36.64-43.54). In those with suspected NAFLD, suspected significant fibrosis (F ≥ F2) was present in 31.07% (27.25-35.16) and suspected advanced fibrosis (F ≥ F3) was present in 20.15% (16.05-24.99).

CONCLUSION

A significant percentage of AYAs are at risk for ALD and NAFLD and a subset of these subjects is at risk for significant fibrosis. Efforts should focus on increasing awareness of the prevalence of ALD and NAFLD in this population and to mitigate modifiable risk factors.

Clinical Factors Associated with Non-Obese Nonalcoholic Fatty Liver Disease Detected among US Adults in the NHANES 2017-2018

NAFLD can occur in non-obese individuals with BMI < 25 kg/m2. Our goal was to examine the prevalence and clinical factors associated with non-obese NAFLD using vibration-controlled transient elastography (VCTE) with controlled attenuation parameter which estimates steatosis and fibrosis among US adults. We aggregated data from the 2017−2018 cycle of NHANES and included adults (age ≥ 20 years) with BMI < 25 kg/m2 with complete data for the survey, medical examination, and VCTE along with controlled attenuation parameter (CAP). We excluded participants with risks of other liver diseases. We considered patients to have non-obese NAFLD if CAP was >285 dB/m, or non-obese NAFLD fibrosis if this CAP criteria was met and liver stiffness was >8.6 kPa. We calculated the adjusted OR and 95% CI for associations with non-obese NAFLD using multivariable logistic regression. The prevalence of non-obese NAFLD was 6.2% and Asian Americans (12.2%) had the highest non-obese NAFLD prevalence. Clinical factors associated with non-obese NAFLD were advanced age and metabolic syndrome (ORadjusted = 6.8, 95% CI 3.0−15.5). In a separate model, we found elevated glucose (ORadjusted = 4.1, 95% CI 2.1−7.9), triglycerides (ORadjusted = 3.8, 95% CI 1.7−8.5), and truncal fat (100-unit increase ORadjusted = 1.07, 95% CI: 1.04−1.10) were associated with higher odds of non-obese NAFLD. Meanwhile, low physical activity (ORadjusted = 2.9, 95% CI 1.2−7.1) was also positively associated with non-obese NAFLD. Non-obese NAFLD is prevalent in the US and is highly associated with metabolic conditions and syndrome. Our results support the importance of considering racial/ethnic differences when investigating NAFLD in a clinical setting.

Liver steatosis and metabolic dysfunction-associated fatty liver disease among HIV-positive and negative adults in urban Zambia

INTRODUCTION

The growing importance of non-communicable diseases (NCDs) and high HIV prevalence in urban African settings may increase the burden of metabolic dysfunction-associated fatty liver disease (MAFLD). We assessed liver steatosis among HIV-positive and negative adults in urban Zambia.

METHODS

Adults 30 years and older who were newly diagnosed with HIV, or tested HIV-negative at two primary care clinics in Lusaka, Zambia, were assessed for liver steatosis. Cardiometabolic data were collected through comprehensive clinical and laboratory assessments. Transient elastography was performed to measure controlled-attenuation parameter (≥248 dB/m). We used multivariable logistic regression models to determine the factors associated with the presence of steatosis.

RESULTS

We enrolled 381 patients, including 154 (40%) antiretroviral therapy-naïve people living with HIV (PLWH) with a median CD4+ count of 247 cells/mm³ and a mean body mass index (BMI) of 23.8 kg/m². Liver steatosis was observed in 10% of participants overall and was more common among HIV-negative adults than in PLWH (15% vs 3%). The proportion of patients with steatosis was 25% among obese (BMI ≥30 kg/m²) participants, 12% among those overweight (BMI 25-29.9 kg/m²), and 7% among those with a BMI <25 kg/m². Among patients with a fasting glucose ≥7 mmol/L or confirmed diabetes, 57% had liver steatosis. In multivariable analyses, HIV status (adjusted odds ratio (aOR) 0.18, 95% CI 0.06 to 0.53), confirmed diabetes or elevated fasting glucose (aOR 3.92, 95% CI 1.57 to 9.78) and elevated blood pressure (aOR 2.95, 95% CI 1.34 to 6.48) were associated with steatosis. The association between BMI>25 kg/m² and liver steatosis was attenuated after adjustment for potential confounders (aOR 1.96, 95% CI 0.88-4.40). Overall, 21 (9%) participants without HIV and 4 (3%) with HIV met the criteria for MAFLD. Among individuals with liver steatosis, 65% (95% CI 49% to 80%) fulfilled criteria of MAFLD, whereas 15 (39%) of them had elevated transaminases and 3 (8%) F2-F4 fibrosis.

CONCLUSIONS

The prevalence of liver steatosis in this urban cohort of HIV-positive and negative adults in Zambia was low, despite a large proportion of patients with high BMI and central obesity. Our study is among the first to report data on MAFLD among adults in Africa, demonstrating that metabolic risk factors are key drivers of liver steatosis and supporting the adoption of the criteria for MAFLD in African populations.

Update on Non-Alcoholic Fatty Liver Disease-Associated Single Nucleotide Polymorphisms and Their Involvement in Liver Steatosis, Inflammation, and Fibrosis: A Narrative Review

Genetic factors are involved in the development, progression, and severity of NAFLD. Polymorphisms in genes regulating liver functions may increase liver susceptibility to NAFLD. Therefore, we conducted this literature study to present recent findings on NAFLD-associated polymorphisms from published articles in PubMed from 2016 to 2021. From 69 selected research articles, 20 genes and 34 SNPs were reported to be associated with NAFLD. These mutated genes affect NAFLD by promoting liver steatosis (PNPLA3, MBOAT7, TM2SF6, PTPRD, FNDC5, IL-1B, PPARGC1A, UCP2, TCF7L2, SAMM50, IL-6, AGTR1, and NNMT), inflammation (PNPLA3, TNF-α, AGTR1, IL-17A, IL-1B, PTPRD, and GATAD2A), and fibrosis (IL-1B, PNPLA3, MBOAT7, TCF7L2, GATAD2A, IL-6, NNMT, UCP, AGTR1, and TM2SF6). The identification of these genetic factors helps to better understand the pathogenesis pathways of NAFLD

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.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the past years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato, the Società Italiana di Diabetologia and the Società Italiana dell'Obesità reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure and Istituto Superiore di Sanità. Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources.Level of evidence Level of evidence of recommendations for each PICO question were reported according to available evidence.

Transient Elastography-Assessed Hepatic Steatosis and Fibrosis Are Associated With Body Composition in the United States

BACKGROUND & AIMS

We examined transient elastography assessed hepatic steatosis and fibrosis distributions and relationships with body composition in a representative United States population sample.

METHODS

Liver stiffness and controlled attenuation parameter (CAP) were assessed on 4870 non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic men and women aged 20 years and over in the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Participants underwent anthropometry and dual-energy x-ray absorptiometry (DXA).

RESULTS

Compared to women, men had higher mean CAP (274.2 dB/m vs 254.4 dB/m) and liver stiffness (6.4 kPa vs 5.5 kPa). CAP and liver stiffness increased through middle age and markedly with BMI. In multivariate-adjusted analysis, CAP in the upper quartile was associated with increased age, BMI, waist-to-hip ratio, diabetes, hypertension, alanine aminotransferase (ALT) and C-reactive protein and decreased HDL cholesterol. After adjustment, non-Hispanic Blacks had lower CAP and non-Hispanic Asians had higher CAP. In multivariate-adjusted analysis, liver stiffness in the upper quartile was associated with male sex, increased age, BMI, diabetes, hepatitis C virus positivity, ALT and CAP. Lower stiffness among Non-Hispanic Asians was not significant after adjustment for BMI. DXA trunk and extremity fat mass were positively related to both CAP and liver stiffness with multivariate adjustment (P < .001 for each). Results were similar with CAP and liver stiffness as continuous characteristics.

CONCLUSIONS

In the United States population, increased anthropometric and DXA body composition measures were associated with higher CAP and liver stiffness. Racial-ethnic differences observed merit further research to elucidate the burden of obesity and liver health disparities.

Clinical and Laboratory Characteristics of Normal Weight and Obese Individuals with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has had, over the past few decades, a progressively growing prevalence among the general population all over the world, in parallel with metabolic conditions such as type 2 diabetes mellitus (T2DM), dyslipidemia, and obesity. However, NAFLD is also detected in 10−13% of subjects with a body mass index (BMI) ≤ 25 kg/m² (lean-NAFLD), whose major risk factors remain unknown. In this study, we aimed to characterize the clinical features and associated risk factors of lean-NAFLD in comparison with obese-NAFLD patients. Consecutive patients diagnosed with NAFLD by vibration-controlled transient elastography and controlled attenuation parameter were prospectively enrolled. Biological and clinical data obtained from the participants were stratified according to their BMI in two groups: lean-NAFLD and obese-NAFLD. In total, 331 patients (56.8% males) were included in the final analysis. Most of the subjects were obese-NAFLD (n = 258, 77.9%) and had a higher prevalence of T2DM, dyslipidemia, and components of the metabolic syndrome, together with abnormal biological parameters. Regarding liver stiffness measurements, the proportion of subjects with at least significant fibrosis (≥F2) was approximately twofold higher among obese-NAFLD (43.81%) in comparison with lean-NAFLD patients (23.29%). Moreover, obese individuals had a higher risk for liver fibrosis (OR = 2.6, 95%, CI 1.5−4.42, p < 0.001) than lean individuals. Although associated metabolic conditions and at least significant liver fibrosis were present in approximately one-quarter of the patients, these were more frequent among obese-NAFLD patients. Therefore, individualized screening strategies for NAFLD should be established according to BMI.

Risk Factors for COVID-19: Diabetes, Hypertension, and Obesity

INTRODUCTION

The recent global pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has involved more than 7 million people worldwide and been associated with more than 400,000 deaths. No clear information is known about all the potential risk factors for COVID-19 or what factors adversely influence its clinical course and mortality. Therefore, we analyzed the role of obesity, type 2 diabetes, and hypertension as risk factors for COVID-19.

METHODS

We identified articles for inclusion by searching PubMed and Google Scholar (last accessed 15 June 2020). Retrospective review of literature. Analysis of epidemiological data concerning obesity prevalence and COVID-19 incidence, particularly in Italy and the USA.

RESULTS

Data from several retrospective studies of prevalence showed that patients with hypertension, type 2 diabetes, and obesity may have more severe COVID-19, intensive care unit admission, and higher mortality rates, but it is not definitively clear if this is an independent association. In general, the prevalence of obesity in patients with COVID-19 seems to be the same as that of the general population throughout the world; however, obesity seems to be associated with more severe disease and mortality in younger (< 60 years) patients. Similar effects seem to occur in patients with diabetes and/or hypertension but at older ages (> 60 years). In strict connection, it has been proposed that the use of drugs inhibiting angiotensin-converting enzyme 2 (ACE-2) or dipeptidyl dipeptidase 4 (DPP-4) might influence viral activity and disease severity since ACE-2 and DPP-4 receptors mediate SARS-CoV-2 entry into the host cells; however, no evidence exists to date that shows that this may be the case.

CONCLUSION

Overall, diabetes, hypertension, and obesity seem to negatively affect the clinical course and disease outcome in patients with COVID-19. However, these data need further confirmation by studies with more accurate data registration.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes, and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the last years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato (AISF), the Società Italiana di Diabetologia (SID) and the Società Italiana dell'Obesità (SIO) reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure (CNEC) and Istituto Superiore di Sanità (ISS). Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources. Level of evidence: Level of evidence of recommendations for each PICO question were reported according to available evidence.

Metabolic-Associated Fatty Liver Disease Is Highly Prevalent in the Postacute COVID Syndrome

Background

A proposal has recently been advanced to change the traditional definition of nonalcoholic fatty liver disease to metabolic-associated fatty liver disease (MAFLD), to reflect the cluster of metabolic abnormalities that may be more closely associated with cardiovascular risk. Long coronavirus disease 2019 (COVID-19) is a smoldering inflammatory condition, characterized by several symptom clusters. This study aims to determine the prevalence of MAFLD in patients with postacute COVID syndrome (PACS) and its association with other PACS-cluster phenotypes.

Methods

We included 235 patients observed at a single university outpatient clinic. The diagnosis of PACS was based on ≥1 cluster of symptoms: respiratory, neurocognitive, musculoskeletal, psychological, sensory, and dermatological. The outcome was prevalence of MAFLD detected by transient elastography during the first postdischarge follow-up outpatient visit. The prevalence of MAFLD at the time of hospital admission was calculated retrospectively using the hepatic steatosis index.

Results

Of 235 patients, 162 (69%) were men (median age 61). The prevalence of MAFLD was 55.3% at follow-up and 37.3% on admission (P < .001). Insulin resistance (odds ratio [OR] = 1.5; 95% confidence interval [CI], 1.14–1.96), body mass index (OR = 1.14; 95% CI, 1.04–1.24), and the metabolic syndrome (OR = 2.54; 95% CI, 1.13–5.68) were independent predictors of MAFLD. The number of PACS clusters was inversely associated with MAFLD (OR = 0.86; 95% CI, .76–0.97). Thirty-one patients (13.2%) had MAFLD with no other associated PACS clusters. All correlations between MAFLD and other PACS clusters were weak.

Conclusions

Metabolic-associated fatty liver disease was highly prevalent after hospital discharge and may represent a specific PACS-cluster phenotype, with potential long-term metabolic and cardiovascular health implications.

Abdominal obesity and dsyglycemia are risk factors for liver fibrosis progression in NAFLD subjects: A population-based study

OBJECTIVE

To investigate longitudinal changes in the liver stiffness measurement (LSM) in the general adult population without known liver disease and to describe its association with metabolic risk factors, with a special focus on subjects with non-alcoholic fatty liver disease (NAFLD) and dysglycemia.

MATERIAL AND METHODS

A longitudinal adult population-based cohort study was conducted in Catalonia. LSM was measured by transient elastography (TE) at baseline and follow-up (median: 4.2 years). Subgroup with NAFLD and dysglycemia were analyzed. Moderate-to-advanced liver fibrosis was defined as LSM ≥8.0 kPa and LSM ≥9.2 kPa respectively.

RESULTS

Among 1.478 subjects evaluated, the cumulative incidence of LSM ≥8.0 kPa and ≥9.2 kPa at follow-up was 2.8% and 1.9%, respectively. This incidence was higher in NAFLD (7.1% for LSM ≥8.0 kPa and 5% for LSM ≥9.2 kPa) and dysglycemia (6.2% for LSM ≥8.0 kPa and 4.7% for LSM ≥9.2 kPa) subgroups. In the global cohort, the multivariate analyses showed that dysglycemia, abdominal obesity and atherogenic dyslipidemia were significantly associated with progression to moderate-to-advanced liver fibrosis. Female sex was negatively associated. In subjects with NAFLD, abdominal obesity and dysglycemia were associated with changes in LSM to ≥8.0 kPa and ≥9.2 kPa at follow-up. A decline in LSM value to <8 kPa was observed in 64% of those subjects with a baseline LSM ≥8.0 kPa.

CONCLUSIONS

In this population study, the presence of abdominal obesity and dysglycemia were the main risk metabolic factors associated with moderate-to-advanced liver fibrosis development over time in general populations as well as in subjects with NAFLD.

Population screening for liver fibrosis: Toward early diagnosis and intervention for chronic liver diseases

Cirrhosis, highly prevalent worldwide, develops after years of hepatic inflammation triggering progressive fibrosis. Currently, the main etiologies of cirrhosis are non-alcoholic fatty liver disease and alcohol-related liver disease, although chronic hepatitis B and C infections are still major etiological factors in some areas of the world. Recent studies have shown that liver fibrosis can be assessed with relatively high accuracy noninvasively by serological tests, transient elastography, and radiological methods. These modalities may be utilized for screening for liver fibrosis in at-risk populations. Thus far, a limited number of population-based studies using noninvasive tests in different areas of the world indicate that a significant percentage of subjects without known liver disease (around 5% in general populations and a higher rate -18% to 27%-in populations with risk factors for liver disease) have significant undetected liver fibrosis or established cirrhosis. Larger international studies are required to show the harms and benefits before concluding that screening for liver fibrosis should be applied to populations at risk for chronic liver diseases. Screening for liver fibrosis has the potential for changing the current approach from diagnosing chronic liver diseases late when patients have already developed complications of cirrhosis to diagnosing liver fibrosis in asymptomatic subjects providing the opportunity of preventing disease progression.

Non-alcoholic fatty liver disease in adults 2021: A clinical practice guideline of the Italian Association for the Study of the Liver (AISF), the Italian Society of Diabetology (SID) and the Italian Society of Obesity (SIO)

Nonalcoholic fatty liver disease (NAFLD) is a common and emerging liver disease in adults, paralleling the epidemic of obesity and diabetes, and leading to worrisome events (hepatocellular carcinoma and end-stage liver disease). In the last years, mounting evidence added insights about epidemiology, natural history, diagnosis and lifestyle-based or drug treatment of NAFLD. In this rapidly evolving scenario, members of the Associazione Italiana per lo Studio del Fegato (AISF), the Società Italiana di Diabetologia (SID) and the Società Italiana dell'Obesità (SIO) reviewed current knowledge on NAFLD. The quality of the published evidence is graded, and practical recommendations are made following the rules and the methodology suggested in Italy by the Centro Nazionale per l'Eccellenza delle cure (CNEC) and Istituto Superiore di Sanità (ISS). Whenever possible, recommendations are placed within the context the Italian Healthcare system, with reference to specific experience and local diagnostic and management resources. Level of evidence: Level of evidence of recommendations for each PICO question were reported according to available evidence.

TM6SF2 rs58542926 is related to hepatic steatosis, fibrosis and serum lipids both in adults and children: A meta-analysis

BACKGROUND AND AIMS

Findings about the associations between transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 and nonalcoholic fatty liver disease have not been consistently replicated, particularly in steatosis and fibrosis. The present study aimed to investigate the associations between the rs58542926T allele and the spectrum of NAFLD and its related metabolic phenotypes.

METHODS

Systematic literature research was performed to analyse the associations between rs58542926 and the spectrum of NAFLD and its related metabolic phenotypes. A random effects meta-analysis with a dominant genetic model was applied.

RESULTS

Data from 123,800 individuals across 44 studies were included in the current meta-analysis.rs58542926 T allele was associated with an increased risk of NAFLD in both adults (OR=1.62; 95% CI: 1.40, 1.86) and children (OR=2.87; 95% CI: 1.85, 4.46). Children had a stronger association with NAFLD (P=0.01). rs58542926 T allele was also positively associated with steatosis progression (mean difference=0.22; 95% CI: 0.05, 0.39) and fibrosis stage (OR=1.50; 95% CI: 1.20, 1.88) in adults. The TM6SF2 rs58542926 T allele was positively associated with ALT in both adults and children (both P<0.01) and only with higher AST in adults (P<0.01). The rs58542926 T allele was negatively associated with serum total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TGs) in both adults and children (all P<0.01).The serum level of TG was much lower in adults than in children (P<0.01).

CONCLUSION

TM6SF2 rs58542926 is involved in the entire spectrum of NAFLD and its related metabolic phenotype, and differences in serum lipid levels were observed between adults and children.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021288163.

The Prevalence of Liver Steatosis and Fibrosis Assessed by Vibration-Controlled Transient Elastography and Controlled Attenuation Parameter in Apparently Healthy Romanian Medical Students

Vibration-Controlled Transient Elastography (VCTE) with Controlled Attenuation Parameter (CAP) is used as a non-invasive method for evaluating liver steatosis and fibrosis simultaneously. In this prospective study, we aimed to assess the prevalence of liver steatosis and fibrosis, as well as the associated risk factors in Romanian medical students by VCTE and CAP score. We used a cut-off CAP score of ≥248 dB/m for the diagnosis of mild steatosis (S1), ≥268 dB/m for moderate steatosis (S2), and ≥280 dB/m to identify severe steatosis (S3). For liver fibrosis, the cut-off values were: ≤5.5 kPa, indicating no fibrosis (F0), 5.6 kPa for mild fibrosis (F1), 7.2 kPa for significant fibrosis (F2), 9.5 kPa for advanced fibrosis (F3), and 12.5 kPa for cirrhosis (F4). In total, 426 Romanian medical students (67.8% females, mean age of 22.22 ± 1.7 years) were evaluated. Among them, 352 (82.6%) had no steatosis (S0), 32 (7.5%) had mild steatosis (S1), 13 (3.1%) had a moderate degree of steatosis (S2), and 29 (6.8%) had severe steatosis (S3). Based on liver stiffness measurements (LSM), 277 (65%) medical students did not have any fibrosis (F0), 136 (31.9%) had mild fibrosis (F1), 10 (2.4%) participants were identified with significant fibrosis (F2), 3 (0.7%) with advanced fibrosis (F3), and none with cirrhosis (F4). In conclusion, the prevalence of liver steatosis and fibrosis is low among Romanian medical students.

Reassessment of the Hispanic Disparity: Hepatic Steatosis Is More Prevalent in Mexican Americans Than Other Hispanics

Hepatic steatosis (HS) is a growing problem in adults worldwide, with racial/ethnic disparity in the prevalence of the disease. The purpose of this study was to characterize the racial/ethnic prevalence of the stages (normal/mild [S0/S1], moderate [S2], and severe [S3]) of HS in Mexican Americans and other Hispanics compared to other racial/ethnic groups. We analyzed data for 5,492 individuals 12 years and older from the newly released National Health and Nutrition Examination Survey 2017-2018, which is a representative sample of the US adult population. HS was diagnosed by FibroScan using controlled attenuation parameter values: S0, <238; S1, 238-259; S2, 260-290; S3, >290. We analyzed the data using the bivariate chi-squared test and multinomial regression. The prevalence of HS overall was 46.9% (S2,16.6%; S3, 30.3%). The prevalence of S3 was highest among Mexican Americans (42.8%), lowest among Blacks (21.6%), 27.6% in other Hispanics, and 30.6% in Whites (P < 0.05). Mexican Americans were about 2 times more likely than Whites to have S2 and S3, while other Hispanics showed no difference from Whites. In an adjusted model, the common risk factors of S2 and S3 were male sex, older ages, high waist-to-hip ratio, body mass index ≥25, and high triglycerides (P < 0.05). Other risk factors for S3 were hemoglobin A1c ≥5.7 and highly sensitive C-reactive protein ≥10 mg/dL (P < 0.05). Conclusion: Our study challenges the paradigm that HS is higher in Hispanics overall; rather, our data show that HS is higher in Mexican Americans and not non-Mexican American Hispanics.

Fasting Ketonuria and the Risk of Incident Nonalcoholic Fatty Liver Disease With and Without Liver Fibrosis in Nondiabetic Adults

INTRODUCTION

Dietary carbohydrate restriction or ketogenic diets are known to be beneficial in preventing liver fat accumulation. However, the effect of ketonemia on the risk of nonalcoholic fatty liver disease (NAFLD) in nondiabetic population is largely unknown. We investigated the association between fasting ketonuria and the risk of incident NAFLD in healthy adults.

METHODS

A cohort of 153,076 nondiabetic Koreans with no hepatic steatosis and low probability of fibrosis at baseline was followed for a median of 4.1 years. The outcome was incident hepatic steatosis with or without liver fibrosis, and it was assessed by liver ultrasound and noninvasive fibrosis indices, including fibrosis-4 and the NAFLD fibrosis score (NFS). Parametric proportional hazard models were used to estimate hazard ratios (HRs) for outcome according to ketonuria status.

RESULTS

Within 677,702.1 person-years of follow-up, 31,079 subjects developed hepatic steatosis. Compared with no ketonuria (reference), fasting ketonuria was significantly associated with a decreased risk of incident hepatic steatosis, with multivariable-adjusted HRs (95% confidence interval) of 0.81 (0.78-0.84). The corresponding HRs for incident hepatic steatosis with intermediate-to-high NFS were 0.79 (0.69-0.90). Similar associations were observed replacing NFS with fibrosis-4. In addition, the presence of persistent ketonuria at both baseline and subsequent visit was associated with the greatest decrease in the adjusted HR for incident NAFLD.

DISCUSSION

Ketonuria was associated with a reduced risk of developing incident hepatic steatosis with and without intermediate-to-high probability of advanced fibrosis in a large cohort of nondiabetic healthy individuals. The role of hyperketonemia in the prevention of NAFLD requires further exploration.

Quantification of Liver Fat Content with Ultrasound: A WFUMB Position Paper

New ultrasound methods that can be used to quantitatively assess liver fat content have recently been developed. These quantitative ultrasound (QUS) methods are based on the analysis of radiofrequency echoes detected by the transducer, allowing calculation of parameters for quantifying the fat in the liver. In this position paper, after a section dedicated to the importance of quantifying liver steatosis in patients with non-alcoholic fatty liver disease and another section dedicated to the assessment of liver fat with magnetic resonance, the current clinical studies performed using QUS are summarized. These new methods include spectral-based techniques and techniques based on envelope statistics. The spectral-based techniques that have been used in clinical studies are those estimating the attenuation coefficient and those estimating the backscatter coefficient. Clinical studies that have used tools based on the envelope statistics of the backscattered ultrasound are those performed by using the acoustic structure quantification or other parameters derived from it, such as the normalized local variance, and that performed by estimating the speed of sound. Experts' opinions are reported.

Interplay between non-alcoholic fatty liver disease and cardiovascular risk in an asymptomatic general population

BACKGROUND AND AIMS

Non-alcoholic fatty liver (NAFLD) is a major cause of liver disease worldwide leading also to a higher risk of cardiovascular events. We aimed to evaluate the impact of fatty liver and fibrosis on cardiovascular risk in a general population.

METHODS

Five hundred and forty-two subjects included in the community-based ABCD (Alimentazione, Benessere Cardiovascolare e Diabete) study were recruited. Steatosis (controlled attenuation parameter > 288 dB/m) and severe fibrosis (low risk, liver stiffness measurement [LSM] < 7.9 KPa with M probe and < 5.7 KPa with XL probe; intermediate risk, LSM 7.9-9.5 KPa with M probe and 5.7-9.2 KPa with XL probe; high risk, LSM ≥ 9.6 KPa with M probe and ≥ 9.3 KPa with XL probe) were assessed with FibroScan. Cardiovascular risk was evaluated by the atherosclerotic cardiovascular disease (ASCVD) risk estimator and defined low if < 5%, borderline if 5-7.4%, intermediate if 7.5-19.9% and high if ≥ 20%. Intima-media thickness (IMT) was measured with ultrasound.

RESULTS

Prevalence of steatosis and of severe fibrosis in this cohort was 31.7% and 4.8%, respectively. ASCVD score was evaluated in patients with and without steatosis and according to the risk of severe fibrosis. By ordinal regression analysis, both steatosis (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.13-2.33, P = 0.009) and severity of fibrosis (OR 1.67, 95% CI 1.18-2.36, P = 0.003) were independent risk factors for a higher ASCVD risk after adjusting for obesity. Subjects with NAFLD, when compared with those without, did not differ for IMT (0.75 vs 0.72 mm; P = 0.11) and IMT ≥ 1 mm (15.6% vs 12.1%; P = 0.24). Higher prevalence of IMT ≥ 1 mm was found in patients at high or intermediate risk of severe fibrosis (24% and 28.6%, respectively) compared with those at low risk (12.1%) (P = 0.03); this association was maintained after adjusting for confounders (OR 2.70, 95% CI 1.01-2.86, P = 0.04).

CONCLUSION

In the setting of a general adult population, the presence of NAFLD and severe fibrosis are associated with to a higher cardiovascular risk profile, pointing towards the need for specific preventive measures.

Fibrosis-4 Index vs Nonalcoholic Fatty Liver Disease Fibrosis Score in Identifying Advanced Fibrosis in Subjects With Nonalcoholic Fatty Liver Disease: A Meta-Analysis

INTRODUCTION

In subjects with nonalcoholic fatty liver disease (NAFLD), advanced fibrosis (AF) carries the highest risk of adverse liver-related events. To reduce the number of unnecessary biopsies, several noninvasive tools (NITs) for the risk stratification of fibrosis have been developed. We conducted this meta-analysis to assess the performance of the fibrosis-4 index (FIB-4) and NAFLD fibrosis scores (NFS), the 2 most common NITs, for the appropriate selection of subjects with AF for biopsy.

METHODS

Four databases were searched until December 2020 (CRD42021224766). Original articles reporting data on the performance of FIB-4 and NFS, interpreted according to standard cutoffs in subjects with biopsy-proven NAFLD, were included. Separate data extractions were performed according to the lower cutoff, the higher cutoff, and the dual threshold approach. The numbers of subjects classified as true-negative, true-positive, false-negative, and false-positive were extracted. Summary operating points were estimated using a random-effects model.

RESULTS

Eighteen studies evaluating 12,604 subjects were included. Participants were adult outpatients with biopsy-proven NAFLD or nonalcoholic steatohepatitis. Overall, a weak-to-moderate performance was found for both scores. The head-to-head comparison showed FIB-4 to be associated with a higher performance in ruling in and NFS in ruling out AF in the single threshold approach, whereas, with the dual threshold approach, a lower prevalence of indeterminate findings was found for FIB-4.

DISCUSSION

This meta-analysis suggested that currently available NITs have a limited performance in identifying AF among subjects with NAFLD. Further studies are needed to optimize existing thresholds or develop new NITs.

Blood pressure, glycemic status and advanced liver fibrosis assessed by transient elastography in the general United States population

OBJECTIVE

Few studies investigated the role of different predictors of advanced liver fibrosis in unselected populations. Here, we estimate the prevalence of steatosis and fibrosis in the general United States population by means of transient elastography and evaluate the impact of blood pressure (BP) and diabetes on disease severity.

METHODS

This is a cross-sectional study of United States adults participating in the 2017-2018 cycle of the National Health and Nutrition Examination Survey. Participants underwent a transient elastography examination, and liver steatosis and fibrosis were estimated through the controlled attenuation parameter (CAP) score and liver stiffness measurement (LSM), respectively.

RESULTS

Four thousand, three hundred and seventy-one participants had reliable transient elastography and BP readings. Steatosis (CAP ≥ 248 dB/m), advanced fibrosis (LSM ≥ 9.6 kPa) and cirrhosis (LSM ≥ 13 kPa) were present in 56.9, 5.5 and 2.9% of participants, respectively. After controlling for potential confounders, risk of steatosis increased proportionally going from participants with optimal (reference) to those with normal [odds ratio (OR) 1.24, 95% confidence interval (CI) 0.83-1.86], high normal (OR 1.41, 95% CI 1.01-1.97) and elevated BP (OR 1.64, 95% CI 1.21-2.21), whereas no significant association was found between BP status and liver fibrosis. Conversely, presence of diabetes increased the risk of both steatosis (OR 2.15, 95% CI 1.49-3.11) and advanced fibrosis (OR 2.25, 95% CI 1.36-3.72).

CONCLUSION

Liver steatosis and fibrosis are highly prevalent in the multiethnic United States adult population, raising concerns for future incidence of cirrhosis and its complications. BP status was associated with a progressively higher risk of steatosis, whereas obesity and diabetes were consistently associated with both steatosis and fibrosis.

Current type 2 diabetes, rather than previous gestational diabetes, is associated with liver disease in U.S. Women

AIM

To investigate the relative contribution of previous gestational diabetes mellitus (GDM) and current type 2 diabetes (T2D) on the development of liver fibrosis, the strongest predictor of end-stage liver disease.

METHODS

This is a population-based cross-sectional study based on data from the 2017-2018 cycle of the National Health and Nutrition Examination Survey. We included women age ≥ 20 years that had delivered at least one live birth and had available data on vibration-controlled transient elastography (VCTE). Liver steatosis and fibrosis were assessed by the median value of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), respectively.

RESULTS

Among the 1699 women included in the study, 144 (10.1%, 95% CI 7.7-13.2) reported a previous diagnosis of GDM. Women with previous GDM were younger, had a higher BMI, a higher prevalence of T2D and were significantly older at the time they had the last live birth. Univariate analysis did not show a significant difference between women with and without a prior history of GDM in terms of both steatosis (44.8% vs 39.4%, p = 0.464) and fibrosis (7.5% vs 7.6%, p = 0.854). Multivariable logistic regression analysis showed that BMI, γ-glutamyltranspeptidase levels, T2D (OR 2.96, 95% CI 1.48-5.93, p < 0.01), HBV and HCV infection were associated with higher odds of significant fibrosis, while previous GDM showed a neutral effect.

CONCLUSIONS

Women with previous GDM that do not develop overt T2D might not experience a poor hepatic prognosis.

Prevalence of Fatty Liver Disease and Fibrosis Detected by Transient Elastography in Adults in the United States, 2017-2018

Fatty liver disease is a clinicopathologic spectrum that encompasses simple steatosis, steatohepatitis, advanced fibrosis, and cirrhosis. Transient elastography has evolved as an accurate technique and noninvasive tool for assessing hepatic fibrosis in clinical practice.¹ The controlled attenuation parameter (CAP) score has been added to elastography, which computes ultrasound attenuation related to hepatic steatosis and improves the measurement of hepatic steatosis.^1,2 Given the unmet need to reckon the current burden of disease, it is essential to estimate the recent prevalence of fatty liver disease and fibrosis assessed by transient elastography in the United States. We investigated the sex-, race/ethnicity-, and body mass index-based prevalence of fatty liver disease and hepatic fibrosis by CAP-enhanced transient elastography in the United States.

The association between hypertension and nonalcoholic fatty liver disease (NAFLD): literature evidence and systems biology analysis

Nonalcoholic fatty liver disease (NAFLD) has become a major public health issue as its progression increases risks of multisystem morbidity and mortality. Recent evidence indicates a more complex relationship between hypertension and NAFLD than previously thought. In this study, a comprehensive literature search was used to gather information supporting the comorbidity phenomenon of hypertension and NAFLD. Then, systems biology approach was applied to identify the potential genes and mechanisms simultaneously associated with hypertension and NAFLD. With the help of protein-protein interaction network-based algorithm, we found that the distance between hypertension and NAFLD was much less than random ones. Sixty-four shared genes of hypertension and NAFLD modules were identified as core genes. Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis indicated that some inflammatory, metabolic and endocrine signals were related to the potential biological functions of core genes. More importantly, drugs used to treat cardiovascular diseases, hypertension, hyperlipidemia, inflammatory diseases and depression could be potential therapeutics against hypertension-NAFLD co-occurrence. After analyzing public OMICs data, ALDH1A1 was identified as a potential therapeutic target, without being affected by reverse causality. These findings give a clue for the potential mechanisms of comorbidity of hypertension and NAFLD and highlight the multiple target-therapeutic strategy of NAFLD for future clinical research.

Liver disease prevalence and severity in people with serious mental illness: a cross-sectional analysis using non-invasive diagnostic tools

BACKGROUND/PURPOSE OF THE STUDY

Little is known about all-cause liver disease in people with serious mental illness (SMI), despite heightened risk factors. We, therefore, prospectively assessed liver disease by etiology and severity in a cross-sectional cohort of people with SMI at a tertiary health service.

METHODS

We recruited 255 people with SMI between August 2019 and March 2020. Liver disease data were derived from structured interview, medical records, biochemical and BBV serological analyses, and vibration-controlled transient elastography (VCTE). Steatosis was determined using a threshold of ≥ 248 db/m via the controlled attenuation parameter (CAP) on VCTE. Liver disease prevalence was assessed descriptively, and predictors of metabolic-dysfunction associated fatty liver disease (MAFLD) analyzed using linear regression and multivariable analysis. Best fit modeling of non-invasive screening tests for MAFLD was also assessed.

RESULTS

Valid VCTE was obtained for 252 (98.9%) participants. Median age was 40 years (IQR 31-49) with male predominance (65.9%). Hepatitis C Virus (HCV) seroprevalence was 14.7% (37/252), with four new viremic cases identified. Hepatic steatosis was diagnosed in 61.5% (155/252) of participants, with MAFLD criteria met in 59.9% (151/252) of cases. Clozapine and paliperidone were associated with hepatic steatosis (CAP + 23.3 db/m, p 0.013 and CAP + 25.5, p 0.037, respectively). Advanced liver disease, defined by LSM ≥ 8.2 kPa, was identified in 26 individuals (10.3%). MAFLD compared to no MAFLD was associated with more advanced liver disease (5.3 kPa, 4.3-6.5 versus 4.9 kPa, 3.9-5.6, p < 0.001).

CONCLUSION

Liver disease is common in people with SMI and should be screened for as part of standard physical health assessment.

The lignan-rich fraction from Sambucus Williamsii Hance ameliorates dyslipidemia and insulin resistance and modulates gut microbiota composition in ovariectomized rats

Menopausal women are susceptible to have high risk of cardiovascular diseases, type II diabetes and osteoporosis due to the metabolic disorder caused by estrogen deficiency. Accumulating evidence supports that gut microbiota is a key regulator of metabolic diseases. Our previous metabolomics study interestingly demonstrated that the anti-osteoporotic effects of lignan-rich fraction (SWCA) from Sambucus wialliamsii Hance were related to the restoration of a series of lipid and glucose metabolites. This study aims to investigate how SWCA modulates lipid and glucose metabolism and the underlying mechanism. Our results show that oral administration of SWCA (140 mg/kg and 280 mg/kg) for 10 weeks alleviated dyslipidemia, improved liver functions, prevented glucose tolerance and insulin actions, attenuated system inflammation and improved intestinal barrier in OVX rats. It also induced a high abundance of Actinobacteria, and restored microbial composition. We are the first to report the protective effects of the lignan-rich fraction from S. williamsii on dyslipidemia and insulin resistance. Our findings provide strong evidence for the application of this lignan-rich fraction to treat menopausal lipid disorder and insulin resistance-related diseases.

Clinical implications of renin-angiotensin system inhibitors for development and progression of non-alcoholic fatty liver disease

Recently, there has been an increasing interest in the therapeutic efficacy of RAS inhibitors (RASi) in patients with non-alcoholic fatty liver disease (NAFLD) because they may reduce oxidative stress, inflammatory markers, and enhanced fibrosis. An objective of this study was to investigate the role of RASi on NAFLD development and progression in a large cohort. We conducted a nested case-control study. Study subjects were classified into two study cohorts according to baseline NAFLD status: non-NAFLD (n = 184,581) and established NALFD (n = 27,565). An NAFLD development or progression case was defined as a patient with newly developed NAFLD or new progression of advanced fibrosis from non-NAFLD and established NALFD cohorts, respectively. A conditional logistic regression analysis was conducted to estimate the associations between RASi exposure and NAFLD development/progression. Overall, no significant association was evident between RASi use and NAFLD development or progression (NAFLD development; ever-user vs. never-user: OR 1.017; 95% CI 0.842-1.230, NAFLD progression; ever-user vs. never-user: aOR 0.942; 95% CI 0.803-1.105). RASi ever-use in cases of individuals who were obese or who had normal fasting plasma glucose (FPG) was associated with reduced risk of both NAFLD development (body mass index (BMI) ≥ 25 kg/m2: 0.708 [95% confidence interval (CI) 0.535-0.937], FPG of < 100 mg/mL: 0.774 [95% CI 0.606-0.987]) and progression (BMI ≥ 25 kg/m2: 0.668 [95% CI 0.568-0.784], FPG of < 100 mg/mL: 0.732 [95% CI 0.582-0.921]). The present study did not verify a significant overall association between RASi use and NAFLD development/progression but suggested that RASi might prevent NAFLD development and progression among specific subjects.

Hepatic Fibrosis Associates With Multiple Cardiometabolic Disease Risk Factors: The Framingham Heart Study

BACKGROUND AND AIMS

NAFLD is increasing in prevalence and will soon be the most common chronic liver disease. Liver stiffness, as assessed by vibration-controlled transient elastography (VCTE), correlates with hepatic fibrosis, an important predictor of liver-related and all-cause mortality. Although liver fat is associated with cardiovascular risk factors, the association between hepatic fibrosis and cardiovascular risk factors is less clear.

APPROACH AND RESULTS

We performed VCTE, assessing controlled attenuation parameter (CAP; measure of steatosis) and liver stiffness measurement (LSM) in 3,276 Framingham Heart Study adult participants (53.9% women, mean age 54.3 ± 9.1 years) presenting for a routine study visit. We performed multivariable-adjusted logistic regression models to determine the association between LSM and obesity-related, vascular-related, glucose-related, and cholesterol-related cardiovascular risk factors. The prevalence of hepatic steatosis (CAP ≥ 290 dB/m) was 28.8%, and 8.8% had hepatic fibrosis (LSM ≥ 8.2 kPa). Hepatic fibrosis was associated with multiple cardiovascular risk factors, including increased odds of obesity (OR, 1.82; 95% CI, 1.35-2.47), metabolic syndrome (OR, 1.49; 95% CI 1.10-2.01), diabetes (OR, 2.67; 95% CI, 1.21-3.75), hypertension (OR, 1.52; 95% CI, 1.15-1.99), and low high-density lipoprotein cholesterol (OR, 1.47; 95% CI, 1.09-1.98), after adjustment for age, sex, smoking status, alcohol drinks/week, physical activity index, aminotransferases, and CAP.

CONCLUSIONS

In our community-based cohort, VCTE-defined hepatic fibrosis was associated with multiple cardiovascular risk factors, including obesity, metabolic syndrome, diabetes, hypertension, and high-density lipoprotein cholesterol, even after accounting for covariates and CAP. Additional longitudinal studies are needed to determine if hepatic fibrosis contributes to incident cardiovascular disease risk factors or events.

Management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is a very common medical condition, driven by a combination of genetic and lifestyle factors, ultimately producing a severe chronic liver disease and increased cardiovascular risk. Most people are asymptomatic for a long time, and their daily life is unaffected, leading to difficulty in identifying and managing people who slowly progress to non-alcoholic steatohepatitis (NASH), NASH-cirrhosis, and eventually hepatocellular carcinoma. Despite advances in the understanding of pathogenic mechanisms and the identification of liver fibrosis as the strongest factor in predicting disease progression, no specific treatments have been approved by regulatory agencies. Outside controlled trials, treatment is generally limited to lifestyle intervention aimed at weight loss. Pioglitazone remains the drug of choice to reduce progression of fibrosis in people with diabetes, although it is often used off-label in the absence of diabetes. Vitamin E is mainly used in children and may be considered in adults without diabetes. Several drugs are under investigation according to the agreed targets of reduced NASH activity without worsening of fibrosis or improving fibrosis without worsening of NASH. Anti-inflammatory, anti-fibrotic agents and metabolism modulators have been tested in either phase III or phase IIb randomized controlled trials; a few failed, and others have produced marginally positive results, but only a few are being tested in extension studies. The development of non-invasive, easily repeatable surrogate biomarkers and/or imaging tools is crucial to facilitate clinical studies and limit liver biopsy.

Quantitative assessment of liver steatosis using ultrasound controlled attenuation parameter (Echosens)

Controlled attenuation parameter (CAP) is the algorithm available on the FibroScan system (Echosens, France) for quantification of liver steatosis. It assesses the ultrasound beam attenuation, which is directly related to liver fat content. The inter-observer reproducibility of the technique is high, with a reported concordance correlation coefficient of 0.82. Specific quality criteria for CAP measurements are not clearly defined yet, and there are conflicting results in the literature. Using liver biopsy as the reference standard, several studies have assessed the CAP performance in grading liver steatosis, and have reported that values are not affected by liver fibrosis. The cutoff for detection of liver steatosis reported in the literature ranges from 222 decibels per meter (dB/m) in a cohort of patients with chronic hepatitis C to 294 dB/m in a meta-analysis of nonalcoholic fatty liver disease (NAFLD) patients. CAP has been used as a tool to noninvasively evaluate the prevalence of NAFLD in groups at risk or in the general population; however, it should be underscored that different CAP cutoffs for steatosis detection (S > 0) were used in different studies, and this limits the robustness of the findings. CAP, alone or combined with other noninvasive indices or biomarkers, has been proposed as a tool for assessing nonalcoholic steatohepatitis or as a noninvasive predictor of prognosis in patients with chronic liver disease. CAP is easy to perform and has become a point-of-care technique. However, there is a large overlap of values between consecutive grades of liver steatosis, and cutoffs are not clearly defined.