Estimating Global Prevalence of Metabolic Dysfunction-Associated Fatty Liver Disease in Overweight or Obese Adults

A poor perspective of self weight significantly increases adverse outcomes in non-alcoholic fatty liver disease (NAFLD)

Background

Non-alcoholic fatty liver disease (NAFLD) is prevalent amongst overweight and obese individuals, and weight loss remains the main mode of treatment for NAFLD patients. Weight perception plays a key role in the efficacy of such treatment. The current study aims to investigate the prevalence, associating factors and implications of poor weight perception amongst such individuals.

Methods

An analysis was done on data collected from NHANES between 1999 and 2018. Comparison was made between NAFLD individuals with and without poor weight perception in terms of prevalence, associated characteristics, and clinical outcomes. Multivariate analysis was used to compare effect size of adverse events associated with NAFLD individuals with poor weight perception.

Results

Of the 12,170 NAFLD patients, 19.2% (CI: 18.5 to 19.9%) had poor weight perception. Poor weight perception was significantly associated with lower education levels, reduced levels of exercise and unhealthier lipid profiles. There was an increased risk in all-cause mortality (HR: 1.18, CI: 1.00 to 1.38, p = 0.047), cardiovascular disease mortality (SHR: 1.33, CI: 1.03 to 1.71, p = 0.026), major adverse cardiovascular events (OR: 1.21 CI: 1.10 to 1.32, p < 0.001), and advanced fibrosis (OR: 1.30, CI: 1.03 to 1.64, p = 0.025) for individuals with poor weight perception.

Conclusion

This study highlights the positive association between appropriate weight perception and better outcomes in individuals with NAFLD. Poor weight perception increased the risk of adverse events and decreased inclination toward seeking weight loss treatment. Greater emphasis should be placed on dealing with weight perception in individuals with NAFLD for better treatment outcomes.

The Effects of Probiotics, Prebiotics and Synbiotics in Non-Alcoholic Fat Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH): A Systematic Review

Modifications in the microbiota caused by environmental and genetic reasons can unbalance the intestinal homeostasis, deregulating the host's metabolism and immune system, intensifying the risk factors for the development and aggravation of non-alcoholic fat liver disease (NAFLD). The use of probiotics, prebiotics and synbiotics have been considered a potential and promising strategy to regulate the gut microbiota and produce beneficial effects in patients with liver conditions. For this reason, this review aimed to evaluate the effectiveness of probiotics, prebiotics, and symbiotics in patients with NAFLD and NASH. Pubmed, Embase, and Cochrane databases were consulted, and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines were followed. The clinical trials used in this study demonstrated that gut microbiota interventions could improve a wide range of markers of inflammation, glycemia, insulin resistance, dyslipidemia, obesity, liver injury (decrease of hepatic enzymes and steatosis and fibrosis). Although microbiota modulators do not play a healing role, they can work as an important adjunct therapy in pathological processes involving NAFLD and its spectrums, either by improving the intestinal barrier or by preventing the formation of toxic metabolites for the liver or by acting on the immune system.

Estimating global prevalence, incidence, and outcomes of non-alcoholic fatty liver disease from 2000 to 2021: systematic review and meta-analysis

BACKGROUND

The increasing burden of non-alcoholic fatty liver disease (NAFLD) worldwide imposes an emerging public health issue. We perform the current study to estimate the global prevalence, incidence, disease progression, and clinical outcomes of NAFLD.

METHODS

A systematic search was conducted in Medline, Embase, Web of Science, Google Scholar, and Cochrane CENTRAL that screened articles in English language published from January 2000 to December 2021. NAFLD prevalence, incidence, rate of disease progression, and outcomes were calculated with the DerSimonian-Laird random effects model with arcsine transformation.

RESULTS

Our search identified 59,156 records, of which 578 studies fulfilled our inclusion criteria. The overall prevalence of NAFLD was 29.38% (95% confidence interval [CI] 28.09-30.69) regardless of the diagnostic techniques. Looking at the group in which the diagnosis was made by ultrasound exclusively, the pooled prevalence was 30.49% (95% CI 29.55-31.43). NAFLD has become more prevalent during the year 2011-2021 (31.63%, 95% CI 30.23-33.04) compared with year 2000-2010 (27.94%, 95% CI 26.23-29.69). The pooled estimation of non-alcoholic steatohepatitis prevalence was 8.26% (95% CI 1.13-21.01), 46.49% (95% CI 35.93-57.20), and 46.72% (95% CI 37.57-55.98) in general population, NAFLD patients, and severe/morbidly obese patients, respectively. Based on a total of 110,142 newly developed NAFLD patients, the pooled incident rate was estimated as 46.24 cases per 1000 person-years (95% CI 43.21-49.30). In patients with NAFLD, the incident rate of hepatocellular carcinoma was 1.46 (95% CI 0.90-2.03) cases per 1000 person-years. The overall pooled estimate of NAFLD related mortality was 23.91 (95% CI 13.55-37.18) death per 1000 person-years.

CONCLUSIONS

The prevalence of NAFLD is increasing globally. It is contributing to poor clinical outcomes including hepatocellular carcinoma and death. Rising awareness and urgent actions are warranted to control the NAFLD pandemic across the globe.

REGISTRATION

PROSPERO, No. CRD42020171104.

Metabolically associated fatty liver disease – a disease of the 21st century: A review

Metabolically associated fatty liver disease (MAFLD) is a widespread chronic disease characterized by increased accumulation of fat in the liver, which is based on metabolic dysfunction. The incidence of MAFLD is well over 20% in most regions of the world and is on an increasing trend. Current thinking considers the etiology and pathogenesis of MAFLD under the concept of "multiple parallel blows". According to this model, the development and progression of the disease are due to the interaction of multiple genetic, environmental and adaptive factors, which include specific genetic polymorphisms (e.g., the PNPLA3 gene) and epigenetic modifications, dietary patterns (e.g. high saturated fat and fructose intake), sedentary activity, obesity, insulin resistance, dysregulation of adipokines, lipotoxicity, oxidative stress, and gut microbiota dysbiosis (small intestinal bacterial overgrowth syndrome). The basis for the diagnosis of MAFLD is the presence of proven hepatic steatosis in combination with one of the following criteria: overweight/obesity, presence of type 2 diabetes mellitus, signs of metabolic dysregulation. Nonmedicamental therapies recommended for patients with MAFLD include weight loss (if overweight or obese), reduction of saturated fatty acid and fructose intake, and inclusion of adequate amounts of omega-3 polyunsaturated fatty acids and dietary fibre (psyllium) in the diet. Pharmacotherapy of MAFLD should be aimed at correcting insulin resistance, improving liver function and reducing the risk of associated diseases.

Sarcopenia: Body Composition and Gait Analysis

Background

Age-induced sarcopenia negatively affects walking stability and increases the risk of falls, which is the leading cause of accidental death in the elderly.

Objective

This study aimed to analyze and contrast body composition and gait characteristics in those with sarcopenia in relation to healthy controls to shed some light on the prevention of falls in elderly patients with sarcopenia.

Materials and Methods

In this study, 68 community dwellers were scanned by the Hologic QDR-4500A Dual-energy X-ray absorptiometry (DXA). The appendicular lean mass index (ALMI) results were used to distinguish the normal participants from those with sarcopenia: 24 in the sarcopenia group, and 44 into the normal group. The participants were asked to undergo gait analysis on a plantar pressure measurement system. Statistical analysis was conducted to contrast both groups' gait and butterfly parameters from their gait test, and then a gait forward dynamics method was performed to quantify the analysis for both groups.

Results

The ALMI of the female was not related to their age (r = 0.06) while that of the male was weakly related (r = 0.17). Body mass index (BMI) from both groups was normal, although with a statistically greater BMI from the normal group compared with sarcopenia (p &lt; 0.001). Greater values and significant differences were found in step length and stride length from the normal elderly group (p &lt; 0.01), and so was the length of the gait line and single support line (p &lt; 0.05). Gait forward dynamics analysis results showed no motor neural or musculoskeletal disorders in their gait performance from the sarcopenia group.

Conclusion

For the elderly, age did not largely affect the ALMI, BMI, or T-score, but BMI and ALMI were strongly correlated. In this study, significant differences were found in certain gait parameters between the elderly with sarcopenia and the normal elderly, which were related to absolute muscle strength, suggesting that sarcopenia was a disease mainly caused by decreased muscle mass. In addition, when abnormities were identified in step length, stride length, length of gait line, or length of single support line, it is proposed to take a DXA scan to confirm whether the elderly suffer from sarcopenia.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: a Review of Shared Cardiometabolic Risk Factors

The prevalence of nonalcoholic fatty liver disease (NAFLD) is rising. NAFLD/nonalcoholic steatohepatitis (NASH) is associated not only with hepatic morbidity and mortality but also with an increased cardiovascular risk. NAFLD and cardiovascular disease (CVD) share several risk factors, such as obesity, metabolic syndrome, hypertension, dyslipidemia, type 2 diabetes, and chronic kidney disease. This review summarizes the evidence linking cardiometabolic risk factors and NAFLD in the context of risk for CVD. The cause of NAFLD/NASH is complex, involving a range of factors from genetics to lifestyle and energy balance. Genetically driven high liver fat content does not appear to be causally associated with increased CVD risk. In contrast, metabolic dysfunction not only predisposes to liver pathology but also leads to a significantly higher CVD risk. Given that NAFLD pathophysiology is influenced by multiple factors, each patient is unique as to their risk of developing CVD and liver pathology. At the same time, the rising burden of NAFLD/NASH is closely linked with the global increase in metabolic disorders, including obesity and type 2 diabetes. Therefore, both personalized therapeutic approaches that recognize individual pathophysiology, as well as public health policies that address the root causes of cardiometabolic risk factors for NAFLD may be needed to effectively address the NAFLD/NASH epidemic.

Silymarin for Treating Toxic Liver Disease: International Consensus Recommendations

Chronic liver disease (CLD) is a leading health problem impacting the quality of life globally. China shares a major global burden of CLD-including alcoholic liver disease, nonalcoholic fatty liver disease/metabolic dysfunction-associated fatty liver disease, and drug-induced liver injury, except for chronic viral hepatitis. Several exogenous toxins or endogenous metabolic insults trigger hepatic pathology toward steatosis, inflammation, and fibrosis, which, if left untreated, may culminate in liver cirrhosis. Oxidative stress is a common pathomechanism underlying all phenotypes of toxic liver injury; thus, these may be brought under a unified entity, viz. toxic liver disease (TLD). Therefore, a common strategy to treat TLD is to use antioxidants as hepatoprotective agents. The cornerstone for treating fatty liver disease is lifestyle modification, diet, exercise, and behavioral therapy, along with the limited use of pharmacological agents. Available preclinical and clinical evidence indicates that silymarin is a hepatoprotective agent with established antioxidant, anti-inflammatory, antifibrotic effects. An international expert panel of clinicians was convened to discuss combining alcoholic liver disease, nonalcoholic fatty liver disease/metabolic dysfunction-associated fatty liver disease, drug-induced liver injury, and liver cirrhosis under the single definition of TLD, based on the shared pathologic mechanism of oxidative stress. The panel highlighted the significance of silymarin as an antioxidant treatment for TLD.

Liver Fibrosis in Asians With Metabolic Dysfunction-Associated Fatty Liver Disease

BACKGROUND & AIMS

This study aimed to evaluate risk factors associated with liver fibrosis in metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

A cross-sectional study of 967 Korean patients with MAFLD involved a cohort from a health screening program during the years 2015-2018. The patients were classified into 4 MAFLD subgroups: group 1 (overweight). group 2 (obese), group 3 (lean/normal weight with metabolic abnormalities), and group 4 (diabetes). Liver fibrosis was assessed based on liver stiffness measurement (LSM) value using 2-dimensional real-time magnetic resonance elastography. We investigated differences in liver fibrosis according to MAFLD subgroup classification and determined the risk factors for significant fibrosis.

RESULTS

The mean age was 50.8 years, and 869 (90%) patients were male. The mean value of LSM in magnetic resonance elastography was 2.48 ± 0.47 kPa. Significant fibrosis (LSM ≥2.97 kPa) was observed in 66 (6.8%) of 967 patients. The proportion of significant fibrosis in MAFLD group 1, group 2, group 3, and group 4 was 1.3%, 5.5%, 6.4%, and 18.9%, respectively (P < .001). Multivariable analysis indicated that the risk factors for significant fibrosis were serum ferritin ≥300 ng/mL (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.10-3.49; P = .023), Fibrosis-4 ≥1.3 (OR, 2.97; 95% CI, 1.68-5.24; P < .001), homeostatic model assessment of insulin resistance ≥2.0 (OR, 2.60; 95% CI, 1.25-5.43; P = .011), metabolic syndrome (OR, 2.53; 95% CI, 1.31-4.88; P = .006), and MAFLD group 4 (OR, 6.93; 95% CI, 1.96-24.51; P = .003). However, the etiology of liver disease was not statistically associated with liver fibrosis.

CONCLUSION

Liver fibrosis in patients with MAFLD varies according to subgroup classification based on diabetes, body mass index, and metabolic risk factors.

Metabolic dysfunction-associated fatty liver disease: a year in review

PURPOSE OF REVIEW

In 2020, a novel comprehensive redefinition of fatty liver disease was proposed by an international panel of experts. This review aims to explore current evidence regarding the impact of this new definition on the current understanding of the epidemiology, pathogenesis, diagnosis, and clinical trials for fatty liver disease.

RECENT FINDINGS

The effectiveness of metabolic dysfunction-associated fatty liver disease (MAFLD) was compared to the existing criteria for nonalcoholic fatty liver disease (NAFLD). Recent data robustly suggest the superior utility of MAFLD in identifying patients at high risk for metabolic dysfunction, the hepatic and extra-hepatic complications, as well as those who would benefit from genetic testing, including patients with concomitant liver diseases. This change in name and criteria also appears to have improved disease awareness among patients and physicians.

SUMMARY

The transformation in name and definition from NAFLD to MAFLD represents an important milestone, which indicates significant tangible progress towards a more inclusive, equitable, and patient-centred approach to addressing the profound challenges of this disease. Growing evidence has illustrated the broader and specific contexts that have tremendous potential for positively influencing the diagnosis and treatment. In addition, the momentum accompanying this name change has included widespread public attention to the unique burden of this previously underappreciated disease.

The Prevalence of Metabolic Dysfunction-Associated Fatty Liver Disease and Its Association with Physical Function and Prognosis in Patients with Acute Coronary Syndrome

It is believed that patients with acute coronary syndrome (ACS) are at an increased risk of nonalcoholic fatty liver disease (NAFLD), which can lead to sarcopenia and physical dysfunction. However, the relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and physical dysfunction and prognosis remains unclear. We investigated the prevalence of MAFLD in patients with ACS to assess the relationship between MAFLD and muscle strength, walking speed, and 6-min walking distance (6 MWD). We reviewed patients with ACS who were assessed for hepatic steatosis using the fatty liver index, and the results were further assessed to determine the presence of MAFLD. Among 479 enrolled hospitalized patients, MAFLD was identified in 234 (48.9%) patients. Multiple regression analysis revealed that MAFLD was independently associated with lower leg strength, gait speed, and 6 MWD (leg strength, p = 0.020; gait speed, p = 0.003 and 6 MWD, p = 0.011). Furthermore, in multivariate Poisson regression models after adjustment for clinical confounding factors, combined MAFLD and reduced physical functions were significantly associated with a higher incidence of clinical events. MAFLD is common in hospitalized patients with ACS and is associated with impaired physical function. Also, the coexistence of MAFLD and lower physical function predict the incidence of clinical events in patients with ACS.

Impact of renaming NAFLD to MAFLD in an Australian regional cohort: Results from a prospective population-based study

BACKGROUND AND AIMS

Clinical and public health implications of the recent redefining of non-alcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD) remain unclear. We sought to determine the prevalence and compare MAFLD with NAFLD in a well-defined cohort.

METHODS

A cross-sectional study was conducted in regional Victoria with participants from randomly selected households. Demographic and health-related clinical and laboratory data were obtained. Fatty liver was defined as a fatty liver index ≥ 60 with MAFLD defined according to recent international expert consensus.

RESULTS

A total of 722 participants were included. Mean age was 59.3 ± 16 years, and 55.3% were women with a median body mass index of 27.8 kg/m² . Most (75.2%) participants were overweight or obese. MAFLD was present in 341 participants giving an unadjusted prevalence of 47.2% compared with a NAFLD prevalence of 38.7%. Fifty-nine (17.5%) participants met the criteria of MAFLD but not NAFLD. The increased prevalence of MAFLD in this cohort was primarily driven by dual etiology of fatty liver. All participants classified as NAFLD met the new definition of MAFLD. Compared with NAFLD subjects, participants with MAFLD had higher ALT (26.0 [14.0] U/L vs 30.0 [23] U/L, P = 0.024), but there were no differences in non-invasive markers for steatosis or fibrosis.

CONCLUSION

Metabolic-associated fatty liver disease is a highly prevalent condition within this large community cohort. Application of the MAFLD definition increased prevalence of fatty liver disease by including people with dual etiologies of liver disease.

Estimating the global prevalence of hepatitis E virus in swine and pork products

Zoonotic transmission of hepatitis E virus (HEV), in particular the genotype (GT) 3 and GT4 strains, constitutes a major one health issue. Swine serves as an important reservoir and the processed pork products essentially contribute to foodborne transmission. This study comprehensively estimated HEV prevalence in domestic pigs, wild boars, and pork products. At global level, we found nearly 60% domestic pigs and 27% wild boars have ever encountered HEV infection based seroprevalence rate. Nearly 13% domestic and 9.5% wild swine are actively infected based on HEV RNA positivity. Importantly, about 10% of commercial pork products are HEV RNA positive, although available data are limited in this respect. Our results indicate the high prevalence rate of HEV infection in pigs and widespread contamination in pork products, although there are substantial variations at regional and country levels. These findings are important for better understanding the global epidemiology and clinical burden of HEV infection in human population related to zoonotic transmission.

Epidemiology, natural history, and diagnosis of metabolic dysfunction-associated fatty liver disease: a comparative review with nonalcoholic fatty liver disease

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) is the most common chronic liver disease worldwide - with an estimated global prevalence of 37%. Different from nonalcoholic fatty liver disease (NAFLD), which is an exclusion diagnosis, MAFLD is defined by a set of positive criteria. This recent change in terminology is challenging because MAFLD and NAFLD denote two similar, albeit not identical, clinical populations. When the diagnostic criteria for MAFLD are applied, liver histology appears more severe and clinical outcomes are less favorable. However, the clinical management of MAFLD and NAFLD remains similar. While liver biopsy is still the reference standard for achieving a final diagnosis, noninvasive imaging- or biomarker-based diagnostic modalities are currently gaining momentum. However, liver biopsy should be recommended when diagnostic challenges exist. In this review, we compared the epidemiology, natural history, and diagnosis of MAFLD with respect to the traditional NAFLD definition.

Lipid-Lowering Responses to Dyslipidemia Determine the Efficacy on Liver Enzymes in Metabolic Dysfunction-Associated Fatty Liver Disease with Hepatic Injuries: A Prospective Cohort Study

PURPOSE

Effective treatment of dyslipidemia with lipid-lowering agents is pivotal in the management of metabolic-associated fatty liver disease (MAFLD) for preventing cardiovascular complications. We explored the associations between improvements in liver injuries indicated by changes in transaminases and a reduction in lipid levels in MAFLD patients with dyslipidemia and elevated transaminases during lipid-lowering therapies.

METHODS

This prospective, cohort study enrolled consecutive MAFLD patients with hyperlipidemia and elevated transaminases. Patients were divided into a group receiving lipid-lowering agents and an age-, sex- and baseline lipid level-matched control group without receiving lipid-lowering agents. Clinical visits were performed at the 1st month and then every 3 months for 1 year.

RESULTS

This study included 541 MAFLD patients (lipid-lowering group: 325 patients; control group: 216 patients). Compared with controls, there was a substantially greater reduction in alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transpeptidase (GGT), triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) in the lipid-lowering group after 12 months (all P < 0.05). The decrease in ALT was positively correlated with the decrease in TC (r = 0.332), TG (r = 0.180), LDL-c (r = 0.253) and apolipoprotein E (ApoE) (r = 0.119), while the decrease in AST was positively correlated with the decrease in TC (r = 0.228) and LDL-c (r = 0.192) (all P<0.05). The greater range of reduction in blood lipids (TC/TG/LDL-c), the higher the transaminase and GGT normalization rate (all P<0.05). Multivariate analysis confirmed that a TG decrease of over 50% remained an independent predictor of transaminase and GGT normalization (OR 2.07, 95% CI 1.12-3.84, P=0.020).

CONCLUSION

Lipid-lowering to target levels might be beneficial to liver injury improvements in MAFLD patients with dyslipidemia when receiving lipid-lowering agents.

Low Screening Rates Despite a High Prevalence of Significant Liver Fibrosis in People with Diabetes from Primary and Secondary Care

Diabetes is a driver of non-alcoholic fatty liver disease (NAFLD) and fibrosis. We determine current practices in examining liver fibrosis in people with diabetes and record prevalence levels in primary and secondary care. We extracted HbA_1c results ≥48 mmol/mol to identify people with diabetes, then examined the proportion who had AST, ALT, and platelets results, facilitating calculation of non-invasive fibrosis tests (NIT), or an enhanced liver fibrosis score. Fibrosis markers were requested in only 1.49% (390/26,090), of which 29.7% (n = 106) had evidence of significant fibrosis via NIT. All patients at risk of fibrosis had undergone transient elastography (TE), biopsy or imaging. TE and biopsy data showed that 80.6% of people with raised fibrosis markers had confirmed significant fibrosis. We also show that fibrosis levels as detected by NIT are marginally lower in patients treated with newer glucose lowering agents (sodium-glucose transporter protein 2 inhibitors, dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists). In conclusion by utilising a large consecutively recruited dataset we demonstrate that liver fibrosis is infrequently screened for in patients with diabetes despite high prevalence rates of advanced fibrosis. This highlights the need for cost-effectiveness analyses to support the incorporation of widespread screening into national guidelines and the requirement for healthcare practitioners to incorporate NAFLD screening into routine diabetes care.

The New Therapeutic Approaches in the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease which is characterized by extremely complex pathogenetic mechanisms and multifactorial etiology. Some of the many pathophysiological mechanisms involved in the development of NAFLD include oxidative stress, impaired mitochondrial metabolism, inflammation, gut microbiota, and interaction between the brain-liver-axis and the regulation of hepatic lipid metabolism. The new therapeutic approaches in the treatment of NAFLD are targeting some of these milestones along the pathophysiological pathway and include drugs like agonists of peroxisome proliferator-activated receptors (PPARs), glucagon-like peptide-1 (GLP-1) agonists, sodium/glucose transport protein 2 (SGLT2) inhibitors, farnesoid X receptor (FXR) agonists, probiotics, and symbiotics. Further efforts in biomedical sciences should focus on the investigation of the relationship between the microbiome, liver metabolism, and response to inflammation, systemic consequences of metabolic syndrome.

Estimating Global Prevalence of Metabolic Dysfunction-Associated Fatty Liver Disease in Overweight or Obese Children and Adolescents: Systematic Review and Meta-Analysis

Objectives: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a new terminology updated from non-alcoholic fatty liver disease (NAFLD). We aim to estimate the global prevalence of MAFLD in overweight or obese children and adolescents, by repurposing existing data on fatty liver disease.

Methods: We screened relevant articles published up to December 2020. Pooled prevalence was calculated using Logit transformations.

Results: Our search returned 35,441 records, of which 156 studies fulfilled the inclusion criteria. The overall prevalence of MAFLD was 33.78% in the general population and 44.94% in a special population based on child obesity clinics, regardless of the diagnostic techniques. For subgroup analysis, MAFLD prevalence was significantly higher in boys compared to girls (36.05 vs. 26.84% in the general population; 50.20 vs. 35.34% in the child obesity clinics-based population). Interestingly, based on study source, the pooled prevalence of MAFLD was 1.5-fold higher in other “fatty liver disease” studies compared to the classical “NAFLD” studies in the general population.

Conclusion: MAFLD is highly prevalent in overweight or obese children and adolescents. Raising awareness and urgent actions are warranted to control the MAFLD pandemic across the globe.

Clinical outcomes in COVID-19 and cirrhosis: a systematic review and meta-analysis of observational studies

BACKGROUND

COVID-19 continues to pose a significant healthcare challenge throughout the world. Comorbidities including diabetes and hypertension are associated with a significantly higher mortality risk. However, the effect of cirrhosis on COVID-19 outcomes has yet to be systematically assessed.

OBJECTIVES

To assess the reported clinical outcomes of patients with cirrhosis who develop COVID-19 infection.

DESIGN/METHOD

PubMed and EMBASE databases were searched for studies included up to 3 February 2021. All English language primary research articles that reported clinical outcomes in patients with cirrhosis and COVID-19 were included. The study was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The risk of bias was assessed using the Quality In Prognostic Score (QUIPS) risk-of-bias assessment instrument for prognostic factor studies template. Meta-analysis was performed using Cochrane RevMan V.5.4 software using a random effects model.

RESULTS

63 studies were identified reporting clinical outcomes in patients with cirrhosis and concomitant COVID-19. Meta-analysis of cohort studies which report a non-cirrhotic comparator yielded a pooled mortality OR of 2.48 (95% CI: 2.02 to 3.04). Analysis of a subgroup of studies reporting OR for mortality in hospitalised patients adjusted for significant confounders found a pooled adjusted OR 1.81 (CI: 1.36 to 2.42).

CONCLUSION

Cirrhosis is associated with an increased risk of all-cause mortality in COVID-19 infection compared to non-cirrhotic patients. Patients with cirrhosis should be considered for targeted public health interventions to prevent COVID-19 infection, such as shielding and prioritisation of vaccination.

Mediating Roles of hsCRP, TNF-α and Adiponectin on the Associations between Body Fat and Fatty Liver Disease among Overweight and Obese Adults

Simple Summary

Body fat has been reported to be related to a higher risk of fatty liver disease (FLD). However, few studies have explored the mediating roles of inflammatory biomarkers or adipokines on the relationships. This study examined the potential mediating effects of high sensitivity C-reactive protein (hsCRP), tumor necrosis factor-α (TNF-α) and adiponectin (APN) in relationships between body fat and FLD in overweight and obese adults. Additionally, gender and age differences were demonstrated. It was concluded that hsCRP has a significant mediating effect on the association between body fat percentage and FLD in females independent of potential covariates. It was also demonstrated that the mediation effect of hsCRP was only significant and more profound in relatively older adults (36–56 years, 38.3%), not significant in the young ones (19–35 years). TNF-α and APN were not significantly associated with body fat percentage or FLD, with no mediating effect on the association between body fat percentage and FLD observed in either gender. In conclusion, hsCRP was a potential mediator on the association between adiposity and FLD, and this mediation is gender-specific and age-specific. The authors hope that the findings could contribute to the further exploration of the inflammatory-related mechanism of obesity-associated FLD.

Abstract

Body fat has been reported to be associated with a higher risk of fatty liver disease (FLD). However, few studies have explored the mediating roles of an inflammatory biomarker or adipokine on the relationships. Here, we examined the potential mediating roles of high sensitivity C-reactive protein (hsCRP), tumor necrosis factor-α (TNF-α) and adiponectin (APN) in relationships between body fat and FLD in overweight and obese adults. Additionally, gender differences will be investigated. In total, 1221 participants aged 19–56 years were included in our study. Body fat percentage was measured with Dual Energy X-ray Absorptiometry (DEXA) and FLD by abdominal ultrasound. Mediation analysis was performed to assess the mediating effect of hsCRP, TNF-α and APN on the associations between BF (%) and FLD by gender differences. We found that hsCRP was significantly associated with body fat percentage in both genders (b = 0.2014, p < 0.0001 and b = 0.1804, p < 0.0001 for male and female, respectively), while hsCRP was associated with FLD only in the female group (b = 0.1609, p = 0.0109) but not in male group (b = 0.4800, p = 0.0603). We observed that hsCRP has a significant mediating effect on the association between body fat percentage and FLD (b = 0.0290, p = 0.0201, mediation ratio: 13.6%) in the female group independent of potential covariates (age, smoking, alcohol drinking and physical activity). TNF-α was not significantly associated with body fat percentage or FLD, with no mediating effect on the association between body fat percentage and FLD in either gender. In conclusion, there is a gender-specific mediation role of hsCRP in the association between body fat and FLD. HsCRP was a potential mediator on the association between adiposity and FLD in the female gender, but not in the male gender. Higher body fat was associated with a higher risk of FLD, and the inflammation level might play a potential mediating role in the association between body fat and FLD among female overweight and obese adults.

[Obesity as a risk factor for diseases of the digestive system]

Currently, the global prevalence of obesity among the worlds adult population is about 650 million people, which makes it possible to consider this chronic metabolic disease as a non-infectious pandemic of the 21st century. It has been proven that obesity is associated with several gastroenterological diseases, while the mechanisms of these associations are extremely heterogeneous and multifactorial. Hypertrophy and hyperplasia of adipocytes in obesity lead to a change in the profile of adipokine production (a decrease in adiponectin, an increase in leptin), an increase in the production of pro-inflammatory cytokines (interleukin-1, 6, 8, tumor necrosis factor ), C-reactive protein, free fatty acids, as well as active forms of oxygen (superoxide radicals, H2O2). All the above induces the development of chronic slowly progressive inflammation, oxidative stress, and insulin resistance. In addition, peptides secreted by adipocytes (adiponectin, leptin, nesfatin-1 and apelin) can modulate gastrointestinal motility, acting both centrally and peripherally. The qualitative and quantitative changes in the intestinal microbiota observed in obese patients (increased Firmicutes and decreased Bacteroidetes) lead to a decrease in the production of short-chain fatty acids and an increase in the intestinal permeability due to disruption of intercellular tight junctions, which leads to increased translocation of bacteria and endotoxins into the systemic circulation. Numerous studies have demonstrated the association of obesity with diseases of the esophagus (gastroesophageal reflux disease, Barretts esophagus, esophageal adenocarcinoma, esophageal motility disorders), stomach (functional dyspepsia, stomach cancer), gallbladder (cholelithiasis, gallbladder cancer), pancreas (acute pancreatitis, pancreatic cancer), liver (non-alcoholic fatty liver disease, hepatocellular carcinoma), intestine (diverticular disease, irritable bowel syndrome, colorectal cancer).

The Troubling Link Between Non-alcoholic Fatty Liver Disease (NAFLD) and Extrahepatic Cancers (EHC)

Non-alcoholic fatty liver disease (NAFLD) is a fast-spreading epidemic across the globe and has serious implications far beyond that of a "benign" liver condition. It is usually an outcome of ectopic fat storage due to chronic positive energy balance leading to obesity and is associated with multiple health problems. While association with cardiovascular disease and hepatocellular cancer is well recognized, it is becoming clear the NAFLD carries with it an increased risk of cancers of extrahepatic tissues. Studies have reported a higher risk for cancers of the colon, breast, prostate, lung, and pancreas. Fatty liver is associated with increased mortality; there is an urgent need to understand that fatty liver is not always benign, and not always associated with obesity. It is, however, a reversible condition and early recognition and intervention can alter its natural history and associated complications.

Current Options and Future Directions for NAFLD and NASH Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with a broad spectrum ranging from simple steatosis to advanced stage of nonalcoholic steatohepatitis (NASH). Although there are many undergoing clinical trials for NAFLD treatment, there is no currently approved treatment. NAFLD accounts as a major causing factor for the development of hepatocellular carcinoma (HCC), and its incidence rises accompanying the prevalence of obesity and diabetes. Reprogramming of antidiabetic and anti-obesity medicine is a major treatment option for NAFLD and NASH. Liver inflammation and cellular death, with or without fibrosis account for the progression of NAFLD to NASH. Therefore, molecules and signaling pathways involved in hepatic inflammation, fibrosis, and cell death are critically important targets for the therapy of NAFLD and NASH. In addition, the avoidance of aberrant infiltration of inflammatory cytokines by treating with CCR antagonists also provides a therapeutic option. Currently, there is an increasing number of pre-clinical and clinical trials undergoing to evaluate the effects of antidiabetic and anti-obesity drugs, antibiotics, pan-caspase inhibitors, CCR2/5 antagonists, and others on NAFLD, NASH, and liver fibrosis. Non-invasive serum diagnostic markers are developed for fulfilling the need of diagnostic testing in a large amount of NAFLD cases. Overall, a better understanding of the underlying mechanism of the pathogenesis of NAFLD is helpful to choose an optimized treatment.

Editorial: International Consensus Recommendations to Replace the Terminology of Non-Alcoholic Fatty Liver Disease (NAFLD) with Metabolic-Associated Fatty Liver Disease (MAFLD)

In 2020, international consensus guidelines recommended the renaming of non-alcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD), supported by diagnostic criteria. MAFLD affects up to 25% of the global population. However, the rates of MAFLD are likely to be underestimated due to the increasing prevalence of type 2 diabetes mellitus (T2DM) and obesity. Within the next decade, MAFLD has been projected to become a major cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide, as well as the most common indication for liver transplantation in the US. This transition in terminology and clinical criteria may increase momentum and clinical evidence at multiple levels, including patient diagnosis, management, and care, and provide the basis for new research areas and clinical development for therapeutics. The diagnostic criteria for MAFLD are practical, simple, and superior to the existing NAFLD criteria for identifying patients at increased risk of developing progressive liver disease. This Editorial aims to present the historical evolution of the terminology for fatty liver disease and the advantages of diagnosis, patient management, and future research on MAFLD.