Non-Alcoholic Fatty Liver Disease in Lean and Non-Obese Individuals: Current and Future Challenges

Μetabolic dysfunction-associated steatotic liver disease: a condition of heterogeneous metabolic risk factors, mechanisms and comorbidities requiring holistic treatment

Μetabolic dysfunction-associated steatotic liver disease (MASLD) comprises a heterogeneous condition in the presence of steatotic liver. There can be a hierarchy of metabolic risk factors contributing to the severity of metabolic dysfunction and, thereby, the associated risk of both liver and extrahepatic outcomes, but the precise ranking and combination of metabolic syndrome (MetS) traits that convey the highest risk of major adverse liver outcomes and extrahepatic disease complications remains uncertain. Insulin resistance, low-grade inflammation, atherogenic dyslipidaemia and hypertension are key to the mechanisms of liver and extrahepatic complications. The liver is pivotal in MetS progression as it regulates lipoprotein metabolism and secretes substances that affect insulin sensitivity and inflammation. MASLD affects the kidneys, heart and the vascular system, contributing to hypertension and oxidative stress. To address the global health burden of MASLD, intensified by obesity and type 2 diabetes mellitus epidemics, a holistic, multidisciplinary approach is essential. This approach should focus on both liver disease management and cardiometabolic risk factors. This Review examines the link between metabolic dysfunction and liver dysfunction and extrahepatic disease outcomes, the diverse mechanisms in MASLD due to metabolic dysfunction, and a comprehensive, personalized management model for patients with MASLD.

Pathophysiological underpinnings of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is emerging as the leading cause of chronic liver disease worldwide, reflecting the global epidemics of obesity, metabolic syndrome, and type 2 diabetes. Beyond its strong association with excess adiposity, MASLD encompasses a heterogeneous population that includes individuals with normal body weight ("lean MASLD") highlighting the complexity of its pathogenesis. This disease results from a complex interplay between genetic susceptibility, epigenetic modifications, and environmental factors, which converge to disrupt metabolic homeostasis. Adipose tissue dysfunction and insulin resistance trigger an overflow of lipids to the liver, leading to mitochondrial dysfunction, oxidative stress, and hepatocellular injury. These processes promote hepatic inflammation and fibrogenesis, driven by cross talk among hepatocytes, immune cells, and hepatic stellate cells, with key contributions from gut-liver axis perturbations. Recent advances have unraveled pivotal molecular pathways, such as transforming growth factor-β signaling, Notch-induced osteopontin, and sphingosine kinase 1-mediated responses, that orchestrate fibrogenic activation. Understanding these interconnected mechanisms is crucial for developing targeted therapies. This review integrates current knowledge on the pathophysiology of MASLD, emphasizing emerging concepts such as lean metabolic dysfunction-associated steatohepatitis (MASH), epigenetic alterations, hepatic extracellular vesicles, and the relevance of extrahepatic signals. It also discusses novel therapeutic strategies under investigation, aiming to provide a comprehensive and structured overview of the evolving MASLD landscape for both basic scientists and clinicians.

Circulating metabolite signatures indicate differential gut-liver crosstalk in lean and obese MASLD

BACKGROUNDAlterations in circulating metabolites have been described in obese metabolic dysfunction-associated steatotic liver disease (MASLD), but data on lean MASLD are lacking. We investigated serum metabolites, including microbial bile acids and short-chain fatty acids (SCFAs), and their association with lean and obese MASLD.METHODSSerum samples from 204 people of European descent were allocated to groups: lean healthy, lean MASLD, obese healthy, and obese MASLD (n = 47). Liquid chromatography-mass spectrometry-based metabolomics and linear model analysis were performed. MASLD prediction was assessed based on least absolute shrinkage and selection operator regression. Functional effects of altered molecules were verified in organotypic 3D primary human liver cultures.RESULTSLean MASLD was characterized by elevated isobutyrate, methionine sulfoxide, propionate, and phosphatidylcholines. Patients with obese MASLD had increased sarcosine and decreased lysine and asymmetric dimethylarginine. Using metabolites, sex, and BMI, MASLD versus healthy could be predicted with a median AUC of 86.5% and 85.6% in the lean and obese subgroups, respectively. Functional experiments in organotypic 3D primary human liver cultures showed propionate and isobutyrate induced lipid accumulation and altered expression of genes involved in lipid and glucose metabolism.CONCLUSIONLean MASLD is characterized by a distinct metabolite pattern related to amino acid metabolism, lipids, and SCFAs, while metabolic pathways of lipid accumulation are differentially activated by microbial metabolites. We highlight an important role of microbial metabolites in MASLD, with implications for predictive and mechanistic assessment of liver disease across weight categories.FUNDINGRobert Bosch Stiftung, Swedish Research Council (2021-02801, 2023-03015, 2024-03401), ERC Consolidator Grant 3DMASH (101170408), Ruth and Richard Julin Foundation for Gastroenterology (2021-00158), SciLifeLab and Wallenberg National Program for Data-Driven Life Science (WASPDDLS22:006), Novo Nordisk Foundation (NNF23OC0085944, NNF23OC0084420), PMU-FFF (E-18/28/148-FEL).

Risk factor analysis and predictive model construction of lean MAFLD: a cross-sectional study of a health check-up population in China

AIM

Cardiovascular disease morbidity and mortality rates are high in patients with metabolic dysfunction-associated fatty liver disease (MAFLD). The objective of this study was to analyze the risk factors and differences between lean MAFLD and overweight MAFLD, and establish and validate a nomogram model for predicting lean MAFLD.

METHODS

This retrospective cross-sectional study included 4363 participants who underwent annual health checkup at Yuyao from 2019 to 2022. The study population was stratified into three groups: non-MAFLD, lean MAFLD (defined as the presence of fatty liver changes as determined by ultrasound in individuals with a BMI < 25 kg/m2), and overweight MAFLD (BMI ≥ 25.0 kg/m2). Subsequent modeling analysis was conducted in a population that included healthy subjects with < 25 kg/m2 (n = 2104) and subjects with lean MAFLD (n = 849). The study population was randomly split (7:3 ratio) to a training vs. a validation cohort. Risk factors for lean MAFLD was identify by multivariate regression of the training cohort, and used to construct a nomogram to estimate the probability of lean MAFLD. Model performance was examined using the receiver operating characteristic (ROC) curve analysis and k-fold cross-validation (k = 5). Decision curve analysis (DCA) was applied to evaluate the clinical usefulness of the prediction model.

RESULTS

The multivariate regression analysis indicated that the triglycerides and glucose index (TyG) was the most significant risk factor for lean MAFLD (OR: 4.03, 95% CI 2.806-5.786). The restricted cubic spline curves (RCS) regression model demonstrated that the relationships between systolic pressure (SBP), alanine aminotransferase (ALT), serum urate (UA), total cholesterol (TCHO), triglyceride (TG), triglyceride glucose (TyG) index, high density lipoprotein cholesterol (HDLC), and MAFLD were nonlinear and the cutoff values for lean MAFLD and overweight MAFLD were different. The nomogram was constructed based on seven predictors: glycosylated hemoglobin A1c (HbA1c), serum ferritin (SF), ALT, UA, BMI, TyG index, and age. In the validation cohort, the area under the ROC curve was 0.866 (95% CI 0.842-0.891), with 83.8% sensitivity and 76.6% specificity at the optimal cutoff. The PPV and NPV was 63.3% and 90.8%, respectively. Furthermore, we used fivefold cross-validation and the average area under the ROC curve was 0.866 (Figure S3). The calibration curves for the model's predictions and the actual outcomes were in good agreement. The DCA findings demonstrated that the nomogram model was clinically useful throughout a broad threshold probability range.

CONCLUSIONS

Lean and overweight MAFLD exhibit distinct metabolic profiles. The nomogram model developed in this study is designed to assist clinicians in the early identification of high-risk individuals with lean MAFLD, including those with a normal BMI but at metabolic risk, as well as those with abnormal blood lipid, glucose, uric acid or transaminase levels. In addition, this model enhances screening efforts in communities and medical screening centers, ultimately ensuring more timely and effective medical services for patients.

Nonalcoholic Fatty Liver Disease Increases the Risk of Lung Abscess: Findings from a Nationwide Cohort Study

Objectives: This study aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD), assessed by the Fatty Liver Index (FLI), and the occurrence of lung abscess within a large population-based cohort. Method: We conducted a nationwide retrospective study using data from 367,930 subjects who underwent National Health check-ups between 2009 and 2018. Cox proportional hazards regression was performed to evaluate the association between the FLI and the incidence of lung abscess and community-acquired pneumonia (CAP) after adjusting for age, sex, and relevant covariates. Results: Among the study population, 455 (0.12%) and 44,934 (12.2%) patients were diagnosed with lung abscesses and CAP, respectively. The cumulative incidence of lung abscess was higher in individuals with elevated FLI values (FLI < 30, 0.10%; 30 ≤ FLI < 60, 0.16%; FLI ≥ 60, 0.18%; p < 0.001), whereas the incidence of CAP decreased across FLI groups (FLI < 30, 12.4%; 30 ≤ FLI < 60, 12.3%; FLI ≥ 60, 11.0%; p < 0.001). After adjusting for covariates, the risk of lung abscess significantly increased in the 30 ≤ FLI < 60 (Hazard ratio (HR) = 1.26; 95% confidence interval (CI), 0.95-1.68; p = 0.115) and the FLI ≥ 60 (HR = 1.67; 95% CI, 1.37-2.29; p < 0.001) groups, although the risk of CAP was relatively small in both groups (30 ≤ FLI < 60; HR = 1.06; 95% CI, 1.03-1.09; p < 0.001) (FLI ≥ 60; HR = 1.13; 95% CI, 1.08-1.12; p < 0.001). Conclusions: Our study provides compelling evidence supporting a potential link between NAFLD, as measured by FLI, and the incidence of lung abscess. These findings suggest the importance of vigilant monitoring of respiratory health in patients with NAFLD and emphasise the need for early detection of possible complications.

Discovery of robust and highly specific microbiome signatures of non-alcoholic fatty liver disease

BACKGROUND

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) with a global prevalence of 30% is multifactorial and the involvement of gut bacteria has been recently proposed. However, finding robust bacterial signatures of NAFLD has been a great challenge, mainly due to its co-occurrence with other metabolic diseases.

RESULTS

Here, we collected public metagenomic data and integrated the taxonomy profiles with in silico generated community metabolic outputs, and detailed clinical data, of 1206 Chinese subjects w/wo metabolic diseases, including NAFLD (obese and lean), obesity, T2D, hypertension, and atherosclerosis. We identified highly specific microbiome signatures through building accurate machine learning models (accuracy = 0.845-0.917) for NAFLD with high portability (generalizable) and low prediction rate (specific) when applied to other metabolic diseases, as well as through a community approach involving differential co-abundance ecological networks. Moreover, using these signatures coupled with further mediation analysis and metabolic dependency modeling, we propose synergistic defined microbial consortia associated with NAFLD phenotype in overweight and lean individuals, respectively.

CONCLUSION

Our study reveals robust and highly specific NAFLD signatures and offers a more realistic microbiome-therapeutics approach over individual species for this complex disease. Video Abstract.

Correlation between hepatic steatosis severity diagnosed by ultrasound and metabolic indexes in elderly patients with MAFLD

Objective

To explore the connection between metabolic parameters and the severity of hepatic steatosis determined through ultrasound in elderly individuals with metabolic dysfunction-associated fatty liver disease (MAFLD).

Methods

4,663 senior individuals who were 65 years of age or older were included in this research. They were examined physically at the Ninghai Street Community Health Service Center in Yantai City between June 7, 2021, and October 15, 2021. There were two categories of individuals identified: the MAFLD group (n = 2,985) and the non-MAFLD group (n = 1,678). Based on liver ultrasonography results, individuals in the MAFLD group were further separated into three groups: mild (n = 2,104), moderate (n = 766), and severe (n = 115). To identify indicators of risk for the severity of hepatic steatosis, metabolic data was contrasted between the groups employing logistic regression.

Results

In comparison to the non-MAFLD group, the MAFLD group showed significantly elevated levels of body mass index (BMI), blood pressure, gender, age, lipid profile, alanine transaminase (ALT), and fasting blood glucose (FBG; p < 0.05). Among individuals with MAFLD, there was a positive correlation between BMI, FBG, ALT, and aspartate transaminase (AST) levels and the severity of hepatic steatosis (p < 0.05). Logistic regression analysis indicated that BMI, female gender, FBG, ALT, triglycerides (TG), and serum uric acid (SUA) constituted risk factors for increased severity of hepatic steatosis in MAFLD.

Conclusion

The severity of hepatic steatosis in elderly MAFLD patients is significantly correlated with female gender, BMI, ALT, FBG, TG, and SUA.

Metabolomics at the cutting edge of risk prediction of MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major public health threat globally. Management of patients afflicted with MASLD and research in this domain are limited by the lack of robust well-established non-invasive biomarkers for diagnosis, prognostication, and monitoring. The circulating metabolome reflects both the systemic metabo-inflammatory milieu and changes in the liver in affected individuals. In this review we summarize the available literature on changes in the different components of the metabolome in MASLD with a focus on changes that are linked to the presence of underlying steatohepatitis, severity of disease activity, and fibrosis stage. We further summarize the existing literature around biomarker panels that are derived from interrogation of the metabolome. Their relevance to disease biology and utility in practice are also discussed. We further highlight potential direction for future studies particularly to ensure they are fit for purpose and suitable for widespread use.

Macrophages and T cells in metabolic disorder-associated cancers

Cancer and metabolic disorders have emerged as major global health challenges, reaching epidemic levels in recent decades. Often viewed as separate issues, metabolic disorders are shown by mounting evidence to heighten cancer risk and incidence. The intricacies underlying this connection are still being unraveled and encompass a complex interplay between metabolites, cancer cells and immune cells within the tumour microenvironment (TME). Here, we outline the interplay between metabolic and immune cell dysfunction in the context of three highly prevalent metabolic disorders, namely obesity; two associated liver diseases, metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH); and type 2 diabetes. We focus primarily on macrophages and T cells, the critical roles of which in dictating inflammatory response and immune surveillance in metabolic disorder-associated cancers are widely reported. Moreover, considering the ever-increasing number of patients prescribed with metabolism disorder-altering drugs and diets in recent years, we discuss how these therapies modulate systemic and local immune phenotypes, consequently impacting cancer malignancy. Collectively, unraveling the determinants of metabolic disorder-associated immune landscape and their role in fuelling cancer malignancy will provide a framework essential to therapeutically address these highly prevalent diseases.

Dietary Rhythms and MASLD-Related Hepatocellular Carcinoma

Dietary rhythms have emerged as a relevant variable in the equation relating nutrition and health. Both experimental and epidemiological studies point to potential beneficial effects of adequate fasting intervals between meals on the evolution of chronic diseases associated with aging. Metabolic dysfunction-associated steatotic liver disease (MASLD) is eminently related to diet and unsurprisingly, diet-based approaches are a mainstay in countering its long-term clinical evolution, including the emergence of hepatocellular carcinoma (HCC). We briefly discuss current evidence linking fasting intervals, MASLD, and HCC and propose a working hypothesis to reconcile some of the apparently conflicting results. This hypothesis relates the beneficial effects of time-restricted eating schedules to the quantity and quality of food, and it is easily amenable to testing.

Effect of Obesity and Metabolic Health Status on Metabolic-Associated Steatotic Liver Disease among Renal Transplant Recipients Using Hepatic Steatosis Index

BACKGROUND/OBJECTIVES

Obesity and metabolic conditions increase the risk of metabolic-associated steatotic liver disease (MASLD). This study examined the risk of MASLD in 137 renal transplant recipients (RTRs) from a single-center hospital on the basis of their obesity and metabolic health status.

METHODS

Participants were categorized into four groups: metabolically healthy nonobese (MHNO), metabolically healthy obese (MHO), metabolically abnormal nonobese (MANO), and metabolically abnormal obese (MAO). MASLD was assessed using the hepatic steatosis index (HSI), calculated as 8 × (aspartate aminotransferase/alanine aminotransferase ratio) + body mass index + 2 (if diabetic) + 2 (if woman). The HSI scores were 29.50 ± 4.55, 38.08 ± 5.44, 33.61 ± 5.23, and 39.86 ± 4.13 in the MHNO, MHO, MANO, and MAO groups, respectively (p < 0.05).

RESULTS

Overall, 25.55% of the participants (57.14% men) were classified as having MASLD (HSI > 36). A multivariate-adjusted regression analysis revealed significantly higher HSI scores in the MAO group than in the MHNO group. Both MHO and MANO groups also had significantly higher HSI scores. The odds ratios for more severe MASLD were 2.74 (95% CI: 0.88-8.52) for the MANO group and 74.59 (95% CI: 13.29-418.68) for the MAO group compared with the MHNO group.

CONCLUSIONS

These findings suggest that RTRs with obesity have a higher risk of MASLD, but even those with a normal weight and metabolic abnormalities are at increased risk.

Diagnosis and Management of Lean Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): A Systematic Review

Lean metabolic dysfunction-associated steatotic liver disease (MASLD) defies traditional views of fatty liver diseases by manifesting in nonobese individuals. The renaming from nonalcoholic fatty liver disease to MASLD underscores a broader understanding of its pathophysiology, highlighting the complex interplay of metabolic factors beyond obesity. Despite its clinical importance, diagnosing and managing lean MASLD remains challenging due to its historical ties to obesity and a general lack of awareness about its unique characteristics. On December 4, 2023, a systematic literature search was conducted across six databases, focusing on peer-reviewed studies in English related to the diagnosis and management of lean MASLD. This study was registered with the International Prospective Register of Systematic Reviews (CRD42023489308). Out of 95 studies following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 43 addressed diagnosis and surveillance, whereas 52 explored management strategies. The results revealed the difficulties in diagnosing lean MASLD, pointing out the limitations of traditional markers and the potential of advanced imaging techniques. Management strategies discussed included lifestyle changes and possible pharmacological treatments tailored to the specific metabolic features of this patient group. The study highlights the necessity for increased clinical awareness, regular monitoring, and personalized therapeutic approaches for lean MASLD. It calls for further research to refine diagnostic criteria and develop targeted treatments, aiming to enhance care for individuals with lean MASLD.

Mitigating Effects of Tanacetum balsamita L. on Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD)

The metabolic syndrome and its associated co-morbidities have been recognized as predisposing risk factors for the development of metabolic-associated fatty liver disease (MAFLD). The present study reports on the beneficial effect of the Tanacetum balsamita methanol-aqueous extract (ETB) at 150 and 300 mg/kg bw on biochemical parameters related to oxidative stress, metabolic syndrome, and liver function in rat animal models with induced MAFLD. ETB was found to be non-toxic with LD50 > 3000 mg/kg and did not affect cell viability of hepatic HEP-G2 cells in a concentration up to 800 μg/mL. The pathology was established by a high-calorie diet and streptozotocin. Acarbose and atorvastatin were used as positive controls. At the higher dose, ETB reduced significantly (p < 0.05) the blood glucose levels by about 20%, decreased lipase activity by 52%, total cholesterol and triglycerides by 50% and 57%, respectively, and restored the amylase activity and leukocytes compared to the MAFLD group. ETB ameliorated oxidative stress biomarkers reduced glutathione and malondialdehyde in a dose-dependent manner. At 300 mg/kg, the beneficial effect of the extract on antioxidant enzymes was evidenced by the elevated catalase, glutathione peroxidase, and superoxide dismutase activity by 70%, 29%, and 44%, accordingly, compared to the MAFLD rats. ETB prevents the histopathological changes related to MAFLD. ETB, rich in 3,5-dicafeoylquinic, chlorogenic, and rosmarinic acids together with the isorhamnetin- and luteolin-glucoside provides a prominent amelioration of MAFLD.

Association between nonalcoholic fatty liver disease and gallstone risk in nonobese and lean individuals

PURPOSE

The association between nonobese/lean nonalcoholic fatty liver disease (NAFLD) and gallstone formation remains unclear. We aimed to assess whether NAFLD is an independent risk factor for gallstones, even in nonobese or lean individuals.

METHODS

We analyzed 265 353 asymptomatic adults who underwent abdominal ultrasonography. The risk of gallstone was assessed on the basis of obesity and NAFLD status.

RESULTS

The overall prevalence rates of NAFLD and gallstones were 27.1% and 2.6%, respectively. The prevalence rates of NAFLD among the 195 204 nonobese and 136 194 lean participants were 14.7% and 7.4%, respectively. Individuals with NAFLD had a significantly increased risk of gallstones (adjusted odds ratio [OR], 1.23; 95% confidence interval [CI], 1.14-1.32). Moreover, NAFLD significantly increased the risk of gallstone (adjusted OR, 1.29; 95% CI, 1.17-1.41) among nonobese individuals. Lean individuals with NAFLD also exhibited a significantly increased risk of gallstones (adjusted OR, 1.20; 95% CI, 1.03-1.40). Furthermore, these findings remained consistent even in nonobese and lean individuals without insulin resistance.

CONCLUSION

Nonobese/lean NAFLD is an independent risk factor for gallstone formation, suggesting its role in gallstone pathogenesis, regardless of obesity status. Therefore, when hepatic steatosis is detected on abdominal ultrasonography, a more thorough evaluation of the gallstones may be necessary, even in nonobese or lean individuals.

Predictive Value of the Chinese Visceral Adiposity Index for Metabolic Dysfunction-Associated Fatty Liver Disease and Elevated Alanine Aminotransferase Levels in Nonobese Chinese Adults: A Cross-Sectional Study

PURPOSE

It is unclear how the Chinese Visceral Adiposity Index (cVAI) relates to metabolic dysfunction-associated fatty liver disease (MAFLD) and alanine aminotransferase (ALT) in nonobese individuals. In this study, we evaluated the ability of the cVAI to predict MAFLD and elevated ALT in nonobese participants.

METHODS

This cross-sectional study recruited 541 nonobese subjects from March 2019 to January 2022 with the age range of 18-80 years. Hepatic steatosis was diagnosed by ultrasound. Participants were divided into four groups according to cVAI quartiles. To assess the associations between cVAI and MAFLD and elevated ALT, multivariate logistic regression was used. Receiver operating characteristic (ROC) curves were generated to evaluate the ability of the cVAI to predict MAFLD and elevated ALT.

RESULTS

Compared to the group with the lowest cVAI, the group with the highest cVAI was positively associated with nonobese MAFLD [16.173 (4.082-64.073), P < 0.001] and elevated ALT [8.463 (2.859-25.049), P < 0.001]. The area under the ROC curve (AUC) of the cVAI was greater than that of WC, waist-to-height ratio, or BMI for predicting nonobese MAFLD in the male, female, > 38 and ≤ 38 years old subgroups (P < 0.05), respectively. In addition, the ability of the cVAI to predict MAFLD was better in females, young individuals, and individuals with a higher education level (P < 0.05). The cVAI also had good predictive ability for elevated ALT levels [0.655 (0.602-0.708)], particularly in females, young people, and highly educated participants. Furthermore, the cVAI was strongly positively correlated with the liver fibrosis score (P < 0.05) and was also a strong indicator of concomitant metabolic syndrome in nonobese MAFLD patients [AUC = 0.688 (0.612-0.763)].

CONCLUSION

The cVAI was strongly related to nonobese MAFLD and elevated ALT. The cVAI may be a reliable and accessible predictor of nonobese MAFLD and elevated ALT.

A High Fibrosis-4 Index is Associated with a Reduction in the Estimated Glomerular Filtration Rate in Non-obese Japanese Patients with Type 2 Diabetes Mellitus

Liver fibrosis is associated with non-alcoholic fatty liver disease (NAFLD), and one of the most important risk factors for NAFLD is type 2 diabetes (T2DM). The Fibrosis-4 (FIB-4) index, a noninvasive liver fibrosis score, has been found to be useful for estimating liver fibrosis. Because individuals with non-obese NAFLD were recently reported to be metabolically unhealthy and have a higher risk of T2DM than individuals with obese NAFLD, we hypothesized that the clinical factors related to a high FIB-4 index would differ between non-obese and obese Japanese T2DM patients. Accordingly, we examined the relationship between clinical factors and the FIB-4 index in non-obese and obese Japanese patients with T2DM. We divided 265 patients into two groups by BMI level - a non-obese group (n = 149) and an obese group (n = 116) - and examined the correlation between the FIB-4 index and clinical parameters. Single regression analysis revealed that a high FIB-4 index was correlated with a reduction in the estimated glomerular filtration rate and hypertension in the non-obese group. Importantly, multiple regression analysis showed that only a reduction in the estimated glomerular filtration rate was significantly associated with a high FIB-4 index in the non-obese group. These results demonstrated that non-obese T2DM patients with a high FIB-4 index might be at risk of kidney dysfunction. Our findings may enable the more appropriate treatment of T2DM patients based on BMI level.

Metabolic dysfunction-associated fatty liver disease/metabolic dysfunction-associated steatotic liver disease: general provisions

The literature review deals with the problem of metabolic dysfunction-associated fatty liver disease that is poorly studied in pediatric gastroenterology. Until recently, primary hepatic steatosis not associated with alcohol intake was defined as non-alcoholic fatty liver disease. Given the unity of the pathogenetic mechanisms underlying primary steatosis, associated steatohepatitis, liver fibrosis with metabolic disorders, such as visceral obesity, insulin resistance, meta-inflammation of adipose tissue, it was proposed to change the terminology. The authors present data on modern nomenclature definitions, etiological factors, prevalence, criteria of metabolic disorders and meta-inflammation associated with this nosology and specific to childhood. Metabolic dysfunction-associated fatty liver disease and nonalcoholic fatty liver disease are characterized by the development of hepatosteatosis. However, a distinguishing feature of metabolic dysfunction-associated fatty liver disease is the presence of metabolic disorders in a patient. It is believed that the use of the term “metabolic dysfunction-associated fatty liver disease” in clinical practice allows doctors to make a diagnosis more reliably and more accurately modify the patient’s lifestyle. Much attention is paid to the description of the heterogeneity of metabolic dysfunction-associated fatty liver disease in clinical practice, and a concise list of therapeutic options for metabolic dysfunction-associated fatty liver disease in childhood is presented.

Trends in Adipose-Derived Stem Cell-Conditioned Medium: A Bibliometric and Visualized Review

Adipose-derived stem cell-conditioned medium (ADSC-CM) has been widely studied and used as a stem cell-based cell-free therapy. Due to the explosion of scientific publications in this field, it is difficult to review all relevant publications systematically, not mention quantitively. In this study, we combined bibliometrics with the conventional review method to summarize, analyze, and visualize the characteristics of nearly all published articles related to ADSC-CM using CiteSpace-a bibliometrics software. We applied this software to quantitively and vividly show (a) annual publications and citations; (b) distributions and co-occurrence networks of countries/regions, authors, journals, and institutions; (c) keyword co-occurrence networks and clusters in different time periods; (d) cocitation networks of references; and (e) ongoing challenges and new topics in ADSC-CM. Altogether, we found that ADSC-CM is at a hot stage with an increasing number of publications and citations, extensive and close scientific collaborations, and dense cocited networks. Impact statement To our best knowledge, it is the first bibliometric and visualized review in the field of adipose-derived stem cell-conditioned medium (ADSC-CM). This review systematically and quantitatively revealed the developments, challenges, and emerging hot spots of ADSC-CM, providing a panoramic view to assist researchers to decide the direction of their future study in the fields of ADSCs and CM derived from stem cells.

A genetic mouse model of lean-NAFLD unveils sexual dimorphism in the liver-heart axis

Lean patients with NAFLD may develop cardiac complications independently of pre-existent metabolic disruptions and comorbidities. To address the underlying mechanisms independent of the development of obesity, we used a murine model of hepatic mitochondrial deficiency. The liver-heart axis was studied as these mice develop microvesicular steatosis without obesity. Our results unveil a sex-dependent phenotypic remodeling beyond liver damage. Males, more than females, show fasting hypoglycemia and increased insulin sensitivity. They exhibit diastolic dysfunction, remodeling of the circulating lipoproteins and cardiac lipidome. Conversely, females do not manifest cardiac dysfunction but exhibit cardiometabolic impairments supported by impaired mitochondrial integrity and β-oxidation, remodeling of circulating lipoproteins and intracardiac accumulation of deleterious triglycerides. This study underscores metabolic defects in the liver resulting in significant sex-dependent cardiac abnormalities independent of obesity. This experimental model may prove useful to better understand the sex-related variability, notably in the heart, involved in the progression of lean-NAFLD.

New aspects characterizing non-obese NAFLD by the analysis of the intestinal flora and metabolites using a mouse model

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem due to the high incidence affecting approximately one-third of the world's population. NAFLD is usually linked to obesity and excessive weight. A subset of patients with NAFLD expresses normal or low body mass index; thus, the condition is called non-obese NAFLD or lean NAFLD. However, patients and healthcare professionals have little awareness and understanding of NAFLD in non-obese individuals. Furthermore, preclinical results from non-obese animal models with NAFLD are unclear. Gut microbiota and their metabolites in non-obese/lean-NAFLD patients differ from those in obese NAFLD patients. Therefore, we analyzed the biochemical indices, intestinal flora, and intestinal metabolites in a non-obese NAFLD mouse model established using a methionine-choline-deficient (MCD) diet. The significantly lean MCD mice had a remarkable fatty liver with lower serum triglyceride and free fatty acid levels, as well as higher alanine transaminase and aspartate transaminase levels than normal mice. 16S RNA sequencing of fecal DNA showed that the overall richness and diversity of the intestinal flora decreased in MCD mice, whereas the Firmicutes:Bacteroidota ratio was increased. g_Tuzzerella, s_Bifidobacterium pseudolongum, and s_Faecalibaculum rodentium were the predominant species in non-obese NAFLD mice. Fecal metabolomics using liquid chromatography-tandem mass spectrometry revealed the potential biomarkers for the prognosis and diagnosis of non-obese NAFLD, including high levels of tyramine glucuronide, 9,12,13-TriHOME, and pantetheine 4'-phosphate, and low levels of 3-carbamoyl-2-phenylpropionaldehyde, N-succinyl-L,L-2,6-diaminopimelate, 4-methyl-5-thiazoleethanol, homogentisic acid, and estriol. Our findings could be useful to identify and develop drugs to treat non-obese NAFLD and lean NAFLD.

IMPORTANCE

Patients and healthcare professionals have little awareness and understanding of NAFLD in non-obese individuals. In fact, about 40% of people with NAFLD worldwide are non-obese, and nearly one-fifth are lean. Lean NAFLD unfortunately may be unnoticed for years and remains undetected until hepatic damage is advanced and the prognosis is compromised. This study focused on the lean NAFLD, screened therapeutic agents, and biomarkers for the prognosis and diagnosis using MCD-induced male C57BL/6J mice. The metabolites tyramine glucuronide, 9,12,13-TriHOME, and pantetheine 4'-phosphate, together with the predominant flora including g_Tuzzerella, s_Bifidobacterium pseudolongum, and s_Faecalibaculum rodentium, were specific in non-obese NAFLD mice and might be used as targets for non-obese NAFLD drug exploration. This study is particularly significant for non-obese NAFLDs that need to be more actively noticed and vigilant.

Association between TyG index trajectory and new-onset lean NAFLD: a longitudinal study

OBJECTIVE

The purpose of this manuscript is to identify longitudinal trajectories of changes in triglyceride glucose (TyG) index and investigate the association of TyG index trajectories with risk of lean nonalcoholic fatty liver disease (NAFLD).

METHODS

Using data from 1,109 participants in the Health Management Cohort longitudinal study, we used Latent Class Growth Modeling (LCGM) to develop TyG index trajectories. Using a Cox proportional hazard model, the relationship between TyG index trajectories and incident lean NAFLD was analyzed. Restricted cubic splines (RCS) were used to visually display the dose-response association between TyG index and lean NAFLD. We also deployed machine learning (ML) via Light Gradient Boosting Machine (LightGBM) to predict lean NAFLD, validated by receiver operating characteristic curves (ROCs). The LightGBM model was used to create an online tool for medical use. In addition, NAFLD was assessed by abdominal ultrasound after excluding other liver fat causes.

RESULTS

The median age of the population was 46.6 years, and 440 (39.68%) of the participants were men. Three distinct TyG index trajectories were identified: "low stable" (TyG index ranged from 7.66 to 7.71, n=206, 18.5%), "moderate stable" (TyG index ranged from 8.11 to 8.15, n=542, 48.8%), and "high stable" (TyG index ranged from 8.61 to 8.67, n=363, 32.7%). Using a "low stable" trajectory as a reference, a "high stable" trajectory was associated with an increased risk of lean-NAFLD (HR: 2.668, 95% CI: 1.098-6.484). After adjusting for baseline age, WC, SBP, BMI, and ALT, HR increased slightly in "moderate stable" and "high stable" trajectories to 1.767 (95% CI:0.730-4.275) and 2.668 (95% CI:1.098-6.484), respectively. RCS analysis showed a significant nonlinear dose-response relationship between TyG index and lean NAFLD risk (χ2 = 11.5, P=0.003). The LightGBM model demonstrated high accuracy (Train AUC 0.870, Test AUC 0.766). An online tool based on our model was developed to assist clinicians in assessing lean NAFLD risk.

CONCLUSION

The TyG index serves as a promising noninvasive marker for lean NAFLD, with significant implications for clinical practice and public health policy.

Effect of CVAI on the incidence of MASLD compared to BMI in populations with different body types: A prospective cohort study in China

BACKGROUND AND AIMS

To explore the relationship between body mass index (BMI), chinese visceral adiposity index (CVAI) and the risk of metabolic dysfunction-associated steatotic liver disease (MASLD) in populations with different body types defined by BMI.

METHODS AND RESULTS

24 191 participants from the Jinchang cohort were involved in the prospective cohort study with a 2.3-year follow-up. Information from epidemiological investigations, comprehensive health examinations and biochemical examinations was collected. MASLD was assessed by abdominal ultrasonography. BMI and CVAI were calculated using recognized formulas. Cox regressions, Restricted cubic spline (RCS) and Receiver operating characteristic (ROC) analysis were performed. The risk of MASLD increased with the increase in BMI and CVAI (Ptrend <0.001), and there was a nonlinear dose-response relationship. In the total population, BMI and CVAI increased the risk of MASLD with adjusted HR (95%CI) of 1.097 (1.091-1.104) and 1.024 (1.023-1.026), respectively. The results were similar in the lean and overweight/obese groups. There was also a nonlinear relationship between CVAI and MASLD (Pnon-linearity<0.001), no matter in which group. The area under the curve of CVAI was significantly higher than that of BMI in females with different body types, and the areas in the whole females were 0.802 (95%CI: 0.787-0.818) and 0.764 (95%CI: 0.747-0.780), respectively. There was no significant difference in the ability of BMI and CVAI to predict MASLD in all-sex and males, either in lean or overweight/obese groups.

CONCLUSIONS

CVAI and BMI were independently associated with the risk of MASLD regardless of body types defined by BMI, and CVAI showed better diagnostic ability for MASLD in females.

Predictors of High Cardiovascular Risk Among Nonobese Patients with Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease in a Chinese Population

Purpose

This study aims to investigate cardiovascular risk factors in nonobese patients with type 2 diabetes (T2DM) and non-alcoholic fatty liver disease (NAFLD) and to determine whether they might be used to predict high-risk individuals effectively.

Patients and Methods

This cross-sectional study included 245 nonobese patients with T2DM who underwent FibroTouch in the National Metabolic Management Center of the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University from January 2021 to December 2022. All individuals were divided into NAFLD and non-NAFLD groups. Patients with NAFLD were further grouped by UAP tertiles (T1, T2 and T3). We created a Cardiovascular Score (total scale: 0-5 points; ≥3 points was defined as high-risk individual) based on baPWV, carotid ultrasound, and urinary microalbumin creatinine ratio (UA/CR) to assess the risk of cardiovascular disease in non-obese T2DM patients with NAFLD. Risk factors were evaluated using univariate and multivariate analysis. The performance of risk factors was compared according to the area under the receiver operating characteristic (ROC) curve.

Results

Atherogenic index of plasma (AIP), atherosclerosis index (AI), prevalence of hypertension, body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA-IR) were higher in the NAFLD group compared to the non-NAFLD group. In T3 group, AIP, AI, BMI and HOMA-IR were higher than those of T1 group. Multivariate logistic regression showed that age, systolic blood pressure, low-density lipoprotein-cholesterol (LDL-C) and AIP were risk factors for cardiovascular disease among nonobese patients with T2DM and NAFLD. The area under the ROC curve for age, systolic blood pressure, LDL-C and AIP were 0.705, 0.688, 0.738 and 0.642, respectively. The area under the ROC curve was 0.895 when combining them.

Conclusion

Age, systolic blood pressure, AIP and LDL-C are all independent risk factors for cardiovascular disease in non-obese individuals with T2DM and NAFLD, which can be combined to identify high-risk populations and carry out intervention.

Recent Progresses on Pathophysiology, Diagnosis, Therapeutic Modalities, and Management of Non-alcoholic Fatty Liver Disorder

Abstract:

Non-alcoholic fatty liver disease (NAFLD) is currently the utmost common chronic liver disorder that happens through all age groups and is identified to occur in 14%-30% of the general population, demonstrating a critical and grossing clinical issue because of the growing incidence of obesity and overweight. From the histological aspect, it looks like alcoholic liver damage, but it happens in patients who avoid remarkable alcohol usage. NAFLD comprises a broad spectrum, ranging from benign hepatocellular steatosis to inflammatory nonalcoholic steatohepatitis (NASH), different levels of fibrosis, and cirrhosis. Patients with NASH are more susceptible to more rapid progression to cirrhosis and hepatocellular carcinoma. There is no single factor that drives proceeding from simple steatosis to NASH. However, a combination of multi parameters such as genetic background, gut microflora, intake of high fat/ fructose dietary contents or methionine/choline-deficient diet, and consequently accumulated hepatocellular lipids mainly including triglycerides and also other bio-analytes, such as free fatty acids, cholesterol, and phospholipids display a crucial role in disease promotion. NAFLD is related to overweight and insulin resistance (IR) and is regarded as the hepatic presentation of the metabolic syndrome, an amalgamation of medical statuses such as hyperlipidemia, hypertension, type 2 diabetes, and visceral obesity. Despite the increasing prevalence of this disease, which imposes a remarkable clinical burden, most affected patients remain undiagnosed in a timely manner, largely related to the asymptomatic entity of NAFLD patients and the unavailability of accurate and efficient noninvasive diagnostic tests. However, liver biopsy is considered a gold standard for NAFLD diagnosis, but due to being expensive and invasiveness is inappropriate for periodic disease screening. Some noninvasive monitoring approaches have been established recently for NAFLD assessment. In addition to the problem of correct disease course prediction, no effective therapeutic modalities are approved for disease treatment. Imaging techniques can commonly validate the screening and discrimination of NAFLD; nevertheless, staging the disease needs a liver biopsy. The present therapeutic approaches depend on weight loss, sports activities, and dietary modifications, although different insulin-sensitizing drugs, antioxidants, and therapeutic agents seem hopeful. This review aims to focus on the current knowledge concerning epidemiology, pathogenesis, and different biochemical experiments and imaging modalities applied to diagnose the different grades of NAFLD and its management, as well as new data about pharmacological therapies for this disorder.

Unique Genetic Features of Lean NAFLD: A Review of Mechanisms and Clinical Implications

Non-alcoholic fatty liver disease (NAFLD) affects 25% of the global population. About 20% have a normal body mass index (BMI) and a variant known as lean NAFLD. Unlike typical NAFLD cases associated with obesity and diabetes, lean NAFLD causes liver disease by mechanisms not related to excess weight or insulin resistance. Genetic disorders are among the major factors in developing lean NAFLD, and genome-wide association studies have identified several genes associated with the condition. This review aims to increase awareness by describing the genetic markers linked to NAFLD and the defects involved in developing lean NAFLD.

Beverage consumption in patients with metabolic syndrome and its association with non-alcoholic fatty liver disease: a cross-sectional study

Introduction

Previous research has examined the association between coffee and tea consumption and non-alcoholic fatty liver disease (NAFLD). Preclinical studies have indicated the potential hepatoprotective properties of cocoa/chocolate. However, clinical research on the consumption of cocoa/chocolate and soft drinks and their relation to NAFLD, particularly among individuals with metabolic syndrome, is limited. This study primarily aimed to assess the association between beverage consumption and NAFLD in these patients.

Methods

This cross-sectional study enrolled adult patients with metabolic syndrome visited the Medicine Outpatient Department at Siriraj Hospital, Thailand, from November 2011 to January 2013. The exclusion criteria were secondary causes of hepatic steatosis, such as excessive alcohol use, viral hepatitis, or drug-induced hepatitis. Participants completed a 23-item self-administered questionnaire covering their beverage consumption habits, including type, frequency, volume, duration, and additives in drinks, namely, coffee, tea, cocoa/chocolate, and soft drinks. To ensure accurate responses, these questionnaires were supplemented by face-to-face interviews. Ultrasonography was employed early in the methodology to diagnose NAFLD. Univariable analyses were used to compare the beverage consumption behaviors of participants with and without NAFLD. Multivariable logistic regression was used to adjust for potential confounders, including total beverage energy intake, age, anthropometric data, laboratory results, and comorbidities.

Results

This study included 505 patients with metabolic syndrome. Of these, 341 (67.5%, 95%CI: 63.2-71.6%) were diagnosed with NAFLD. The consumption rates of coffee, cocoa/chocolate, and soft drinks were similar between the two groups. However, tea consumption was significantly more common in patients with NAFLD (68.3% vs. 51.8%, p < 0.001). The groups had no significant differences in caffeine intake or total energy intake from beverages. Notably, daily intake of three or more cups of coffee was correlated with a reduced prevalence of NAFLD, with an adjusted odds ratio of 0.35 (95%CI: 0.14-0.89).

Conclusion

This study revealed that patients with metabolic syndrome, irrespective of NAFLD status, exhibited similar patterns of beverage consumption. While no definitive associations were identified between the intake of coffee, tea, cocoa/chocolate, or soft drinks and NAFLD, a notable exception was observed. A higher consumption of coffee (≥3 cups daily) was associated with a lower prevalence of NAFLD.

Non-alcoholic fatty liver disease and gut microbial dysbiosis- underlying mechanisms and gut microbiota mediated treatment strategies

Non-alcoholic fatty liver disease (NAFLD) is by far the most prevalent form of liver disease worldwide. It's also the leading cause of liver-related hospitalizations and deaths. Furthermore, there is a link between obesity and NAFLD risk. A projected 25% of the world's population grieves from NAFLD, making it the most common chronic liver disorder. Several factors, such as obesity, oxidative stress, and insulin resistance, typically accompany NAFLD. Weight loss, lipid-lowering agents, thiazolidinediones, and metformin help prominently control NAFLD. Interestingly, pre-clinical studies demonstrate gut microbiota's potential causal role in NAFLD. Increased intestinal permeability and unhindered transport of microbial metabolites into the liver are the major disruptions due to gut microbiome dysbiosis, contributing to the development of NAFLD by dysregulating the gut-liver axis. Hence, altering the pathogenic bacterial population using probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT) could benefit patients with NAFLD. Therefore, it is crucial to acknowledge the importance of microbiota-mediated therapeutic approaches for NAFLD and comprehend the underlying mechanisms that establish a connection between NAFLD and gut microbiota. This review provides a comprehensive overview of the affiliation between dysbiosis of gut microbiota and the progress of NAFLD, as well as the potential benefits of prebiotic, probiotic, synbiotic supplementation, and FMT in obese individuals with NAFLD.

Coagulation Dysfunctions in Non-Alcoholic Fatty Liver Disease-Oxidative Stress and Inflammation Relevance

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. Its incidence is progressively rising and it is possibly becoming a worldwide epidemic. NAFLD encompasses a spectrum of diseases accounting for the chronic accumulation of fat within the hepatocytes due to various causes, excluding excessive alcohol consumption. In this study, we aimed to focus on finding evidence regarding the implications of oxidative stress and inflammatory processes that form the multifaceted pathophysiological tableau in relation to thrombotic events that co-occur in NAFLD and associated chronic liver diseases. Recent evidence on the pathophysiology of NAFLD suggests that a complex pattern of multidirectional components, such as prooxidative, proinflammatory, and prothrombotic components, better explains the multiple factors that promote the mechanisms underlying the fatty acid excess and subsequent processes. As there is extensive evidence on the multi-component nature of NAFLD pathophysiology, further studies could address the complex interactions that underlie the development and progression of the disease. Therefore, this study aimed to describe possible pathophysiological mechanisms connecting the molecular impairments with the various clinical manifestations, focusing especially on the interactions among oxidative stress, inflammation, and coagulation dysfunctions. Thus, we described the possible bidirectional modulation among coagulation homeostasis, oxidative stress, and inflammation that occurs in the various stages of NAFLD.

Metabolic Associated Fatty Liver Disease (MAFLD) and COVID-19 Infection: An Independent Predictor of Poor Disease Outcome?

Background and Objectives: Early reports on COVID-19 infection suggested that the SARS-CoV-2 virus solely attacks respiratory tract cells. As the pandemic spread, it became clear that the infection is multiorganic. Metabolic associated fatty liver disease (MAFLD) is a chronic liver disease strongly associated with insulin resistance and diabetes. The aim of this study was to assess a possible interplay between MAFLD and COVID-19 infection and its implication in COVID-19 outcome. Materials and Methods: A retrospective observational study, including 130 COVID-19 positive patients was conducted. MAFLD diagnosis was made based on the International Consensus criteria. Patients were divided into two groups, group A (MAFLD) and group B (nonMAFLD). Anthropometric and laboratory analysis were obtained. COVID-19 severity was assessed using the NEWS2 score. Disease outcome was threefold and regarded as discharged, patients who required mechanical ventilation (MV), and deceased patients. Results: MAFLD prevalence was 42%, 67% of patients were discharged, and 19% needed MV. Mortality rate was 14%. MAFLD patients were significantly younger (p < 0.001), and had higher body mass index (p < 0.05), respiratory rate (p < 0.05) and systolic blood pressure (p < 0.05) than nonMAFLD patients. Regarding metabolic syndrome and inflammatory markers: group A had significantly higher glycemia at admission (p = 0.008), lower HDL-c (p < 0.01), higher triglycerides (p < 0.01), CRP (p < 0.001), IL-6 (p < 0.05) and ferritin (p < 0.05) than group B. MAFLD was associated with more prevalent type 2 diabetes (p = 0.035) and hypertension (p < 0.05). MAFLD patients had a more severe disease course (NEWS2 score, 6.5 ± 0.5 vs. 3 ± 1.0, p < 0.05). MAFLD presence was associated with lower patient discharge (p < 0.01) and increased need for MV (p = 0.024). Multiple regression analysis showed that BMI (p = 0.045), IL-6 (p = 0.03), and MAFLD (p < 0.05) are significant independent risk factors for a poor COVID-19 outcome. Conclusions: The prevalence of MAFLD is relatively high. MAFLD patients had a more severe COVID-19 clinical course and worse disease outcome. Our results imply that early patient stratification and risk assessment are mandatory in order to avoid poor outcomes.

Association between the lean nonalcoholic fatty liver disease and risk of incident type 2 diabetes in a healthy population of Northwest China: a retrospective cohort study with a 2-year follow-up period

Aims

We aimed to explore the metabolic features of lean nonalcoholic fatty liver disease (Lean-NAFLD) and its association with the risk of incident type 2 diabetes in young and middle-aged people.

Methods

We conducted a retrospective cohort study of 3001 participants who were enrolled in a health check-up program from January 2018 to December 2020 in the Health Management Center of Karamay People's Hospital. The age, sex, height, weight, body mass index (BMI), blood pressure, waist circumference (WC), fasting plasma glucose (FPG), lipid profiles, serum uric acid and alanine aminotransferase (ALT) of the subjects were collected. The cutoff point of BMI for lean nonalcoholic fatty liver disease is <25 kg/m². A COX proportional hazard regression model was used to analyze the risk ratio of lean nonalcoholic fatty liver disease to type 2 diabetes mellitus.

Results

Lean NAFLD participants had many metabolic abnormalities, such as overweight and obesity with nonalcoholic fatty liver disease. Compared with lean participants without nonalcoholic fatty liver disease, the fully adjusted hazard ratio (HR) for lean participants with nonalcoholic fatty liver disease was 3.83 (95% CI 2.02-7.24, p<0.01). In the normal waist circumference group (man<90cm, woman<80 cm), compared with lean participants without NAFLD, the adjusted hazard ratios (HRs) of incident type 2 diabetes for lean participants with NAFLD and overweight or obese participants with NAFLD were 1.93 (95% CI 0.70-5.35, p>0.05) and 4.20 (95% CI 1.44-12.22, p<0.05), respectively. For excess waist circumference (man≥90 cm, woman ≥80 cm) compared with lean participants without NAFLD, the adjusted hazard ratios (HRs) of incident type 2 diabetes for lean participants with NAFLD and overweight or obese participants with NAFLD were 3.88 (95% CI 1.56-9.66, p<0.05) and 3.30 (95% CI 1.52-7.14, p<0.05), respectively.

Conclusion

Abdominal obesity is the strongest risk factor for type 2 diabetes in lean nonalcoholic fatty liver disease.

Lean nonalcoholic fatty liver disease and sarcopenia

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases in the world. The risk factor for NAFLD is often considered to be obesity, but it can also occur in people with lean type, which is defined as lean NAFLD. Lean NAFLD is commonly associated with sarcopenia, a progressive loss of muscle quantity and quality. The pathological features of lean NAFLD such as visceral obesity, insulin resistance, and metabolic inflammation are inducers of sarcopenia, whereas loss of muscle mass and function further exacerbates ectopic fat accumulation and lean NAFLD. Therefore, we discussed the association of sarcopenia and lean NAFLD, summarized the underlying pathological mechanisms, and proposed potential strategies to reduce the risks of lean NAFLD and sarcopenia in this review.

Association between remnant lipoprotein cholesterol levels and risk of non-alcoholic fatty liver disease in non-obese populations: a Chinese longitudinal prospective cohort study

OBJECTIVES

The association between remnant lipoprotein cholesterol (RLP-C) levels and the incidence of non-alcoholic fatty liver disease (NAFLD) is unclear, especially in non-obese populations.

SETTING

We used data from a health assessment database. The assessment was conducted at the Wenzhou Medical Center from January 2010 to December 2014. The patients were divided into low, middle and high RLP-C groups according to tertiles of RLP-C, and baseline metabolic parameters were compared among the three groups. Kaplan-Meier analysis and Cox proportional hazards regression were used to evaluate the relationship between RLP-C and NAFLD incidence. Additionally, sex-specific associations between RLP-C and NAFLD were examined.

PARTICIPANTS

16 173 non-obese participants from the longitudinal healthcare database.

OUTCOME MEASURE

NAFLD was diagnosed using abdominal ultrasonography and clinical history.

RESULTS

Participants with higher RLP-C levels tended to have higher blood pressure, liver metabolic index and lipid metabolism index than those with middle or low RLP-C (p<0.001). During the 5-year follow-up period, 2322 (14.4%) participants developed NAFLD. Participants with high and middle RLP-C levels were at a higher risk of developing NAFLD, even after adjusting for age, sex, body mass index and main metabolic parameters (HR 1.6, 95% CI 1.3, 1.9, p<0.001; and HR 1.3, 95% CI 1.1, 1.6, p=0.01, respectively). The effect was consistent in subgroups of different ages, systolic blood pressures and alanine aminotransferase levels, except for sex and direct bilirubin (DBIL). These correlations, beyond traditional cardiometabolic risk factors, were stronger in males than females (HR 1.3 (1.1, 1.6) and HR 1.7 (1.4, 2.0), p for interaction 0.014 for females and males, respectively).

CONCLUSIONS

In non-obese populations, higher RLP-C levels indicated a worse cardiovascular metabolic index. RLP-C was associated with the incidence of NAFLD, independent of the traditional risk factors of metabolism. This correlation was more substantial in the male and low DBIL subgroups.

Improved body composition decreases the fat content in non-alcoholic fatty liver disease, a meta-analysis and systematic review of longitudinal studies

Background

Based on cross-sectional studies, there is a link between body composition parameters and steatosis in non-alcoholic fatty liver disease (NAFLD). However, whether long-term changes in different body composition parameters will result in NAFLD resolution is unclear. Therefore, we aimed to summarize the literature on longitudinal studies evaluating the association between NAFLD resolution and body composition change.

Methods

Based on the recommendations of the Cochrane Handbook, we performed a systematic search on September 26th, 2021, in three databases: Embase, MEDLINE (via PubMed), and Cochrane Central Register of Controlled Trials (CENTRAL). Eligible studies reported on patients with NAFLD (liver fat >5%) and examined the correlation between body composition improvement and decrease in steatosis. We did not have pre-defined body composition or steatosis measurement criteria. Next, we calculated pooled correlation coefficient (r) with a 95% confidence interval (CI). Furthermore, we narratively summarized articles with other statistical methods.

Results

We included 15 studies in our narrative review and five in our quantitative synthesis. Based on two studies with 85 patients, we found a pooled correlation coefficient of r = 0.49 (CI: 0.22-0.69, Spearman's correlation) between the change of visceral adipose tissue and liver steatosis. Similarly, based on three studies with 175 patients, the correlation was r = 0.33 (CI: 0.19-0.46, Pearson's correlation). On the other hand, based on two studies with 163 patients, the correlation between subcutaneous adipose tissue change and liver steatosis change was r = 0.42 (CI: 0.29-0.54, Pearson's correlation). Furthermore, based on the studies in the narrative synthesis, body composition improvement was associated with steatosis resolution.

Conclusions

Based on the included studies, body composition improvement may be associated with a decrease in liver fat content in NAFLD.

Systematic review registration

Identifier: CRD42021278584.

Higher mortality among lean patients with non-alcoholic fatty liver disease despite fewer metabolic comorbidities

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) can develop in individuals who are not overweight. Whether lean persons with NAFLD have lower mortality and lower incidence of cirrhosis, cardiovascular diseases (CVD), diabetes mellitus (DM) and cancer than overweight/obese persons with NAFLD remains inconclusive. We compared mortality and incidence of cirrhosis, CVD, DM and cancer between lean versus non-lean persons with NAFLD.

METHODS

This is a retrospective study of adults with NAFLD in a single centre from 2012 to 2021. Primary outcomes were mortality and new diagnosis of cirrhosis, CVD, DM and cancer. Outcomes were modelled using competing risk analysis and Cox proportional hazards regression analysis.

RESULTS

A total of 18,594 and 13,420 patients were identified for cross-sectional and longitudinal analysis respectively: approximately 11% lean, 25% overweight, 28% class 1 obesity and 35% class 2-3 obesity. The median age was 51.0 years, 54.6% were women. The median follow-up was 49.3 months. Lean patients had lower prevalence of metabolic diseases at baseline and lower incidence of cirrhosis and DM than non-lean patients and no difference in CVD, any cancer or obesity-related cancer during follow-up. However, lean patients had significantly higher mortality with incidence per 1000 person-years of 16.67, 10.11, 7.37 and 8.99, respectively, in lean, overweight, obesity class 1 and obesity class 2-3 groups respectively.

CONCLUSIONS

Lean patients with NAFLD had higher mortality despite lower incidence of cirrhosis and DM, and similar incidence of CVD and cancer and merit similar if not more attention as non-lean patients with NAFLD.

Nonalcoholic Fatty Liver Disease: A Unique Entity or Part of the Metabolic Syndrome or Both

Nonalcoholic fatty liver disease (NAFLD) is a global public health problem. NAFLD is bidirectionally correlated with metabolic syndrome, which includes obesity, type 2 diabetes, hypertension, and dyslipidemia as major components. The presence of metabolic syndrome is associated with a higher prevalence of NAFLD, and vice versa. Also, the presence of metabolic syndrome in patients with NAFLD has been linked to a higher risk of cardiovascular diseases, liver-related complications, extrahepatic malignancies, and mortality, and possibly vice versa. Multidisciplinary care pathways including lifestyle modifications, control of metabolic risk, and potentially beneficial treatments are important to improve the clinical outcomes of patients with NAFLD.

Special Population: Lean Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity but around 10% to 20% of patients with NAFLD have normal body mass index, a condition referred to as lean or nonobese NAFLD. Although lean patients more often have milder liver disease, a proportion may nonetheless develop steatohepatitis and advanced liver fibrosis. Both genetic and environmental factors contribute to the development of NAFLD. Noninvasive tests have similarly good accuracy as initial assessments for lean NAFLD. Future studies should determine the most appropriate treatment in this special population.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Correlation between nonalcoholic fatty liver disease and left ventricular diastolic dysfunction in non-obese adults: a cross-sectional study

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with a greater risk of developing cardiovascular disease and have adverse impacts on the cardiac structure and function. Little is known about the effect of non-obese NAFLD upon cardiac function. We aimed to compare the echocardiographic parameters of left ventricle (LV) between non-obese NAFLD group and control group, and explore the correlation of non-obese NAFLD with LV diastolic dysfunction.

METHODS AND RESULTS

In this cross-sectional study, 316 non-obese inpatients were enrolled, including 72 participants with NAFLD (non-obese NAFLD group) and 244 participants without NAFLD (control group). LV structural and functional indices of two groups were comparatively analyzed. LV diastolic disfunction was diagnosed and graded using the ratio of the peak velocity of the early filling (E) wave to the atrial contraction (A) wave and E value. Compared with control group, the non-obese NAFLD group had the lower E/A〔(0.80 ± 0.22) vs (0.88 ± 0.35), t = 2.528, p = 0.012〕and the smaller LV end-diastolic diameter〔(4.51 ± 0.42)cm vs (4.64 ± 0.43)cm, t = 2.182, p = 0.030〕. And the non-obese NAFLD group had a higher prevalence of E/A < 1 than control group (83.3% vs 68.9%, X² = 5.802, p = 0.016) while two groups had similar proportions of LV diastolic dysfunction (58.3% vs 53.7%, X² = 0.484, p = 0.487). Multivariate logistic regression analysis showed that non-obese NAFLD was associated with an increase in E/A < 1 (OR = 6.562, 95%CI 2.014, 21.373, p = 0.002).

CONCLUSIONS

Non-obese NAFLD was associated with decrease of E/A, while more research will be necessary to evaluate risk of non-obese NAFLD for LV diastolic dysfunction in future.

Small Intestinal Bacterial Overgrowth and Non-Alcoholic Fatty Liver Disease: What Do We Know in 2023?

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with the pathological accumulation of lipids inside hepatocytes. Untreated NAFL can progress to non-alcoholic hepatitis (NASH), followed by fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The common denominator of the above-mentioned metabolic disorders seems to be insulin resistance, which occurs in NAFLD patients. Obesity is the greatest risk factor for lipid accumulation inside hepatocytes, but a part of the NAFLD patient population has a normal body weight according to the BMI index. Obese people with or without NAFLD have a higher incidence of small intestinal bacterial overgrowth (SIBO), and those suffering from NAFLD show increased intestinal permeability, including a more frequent presence of bacterial overgrowth in the small intestine (SIBO). The health consequences of SIBO are primarily malabsorption disorders (vitamin B12, iron, choline, fats, carbohydrates and proteins) and bile salt deconjugation. Undetected and untreated SIBO may lead to nutrient and/or energy malnutrition, thus directly impairing liver function (e.g., folic acid and choline deficiency). However, whether SIBO contributes to liver dysfunction, decreased intestinal barrier integrity, increased inflammation, endotoxemia and bacterial translocation is not yet clear. In this review, we focus on gut–liver axis and discuss critical points, novel insights and the role of nutrition, lifestyle, pre- and probiotics, medication and supplements in the therapy and prevention of both SIBO and NAFLD.

Epidemiology and prevalence of lean nonalcoholic fatty liver disease and associated cirrhosis, hepatocellular carcinoma, and cardiovascular outcomes in the United States: a population-based study and review of literature

BACKGROUNDS

Nonalcoholic fatty liver disease (NAFLD) is linked to obesity and metabolic syndrome conditions. However, a subset of NAFLD patients express a normal or low body mass index (lean NAFLD [L-NAFLD]). Our aim is to compare the prevalence of L-NAFLD to the obesity-associated NAFLD in the United States by assessing prevalence, potential risk factors, liver-related complications, and coronary artery disease outcomes.

METHODOLOGY

A multicenter database (Explorys Inc.) of >70 million patients across the United States was screened. A cohort of patients with "nonalcoholic fatty liver" between 1999 and 2021 was identified. Two sub-cohorts of NAFLD patients were identified: those with a body mass index (BMI) < 25 kg/m² (L-NAFLD) and those with a BMI > 30 kg/m² (obesity-associated NAFLD). We excluded patients with age <18 and those who have viral hepatitis, hemochromatosis, Wilson's disease, biliary cirrhosis, alcoholic liver disease, cystic fibrosis, alpha-1-antitrypsin deficiency, and autoimmune hepatitis. Multivariate analysis was performed to adjust for confounders.

RESULTS

68 892 260 individuals were screened. NAFLD prevalence was four per 100 000, and L-NAFLD prevalence was 0.6 per 100 000. Compared with those without, patients with L-NAFLD tended to be older (OR 2.16), females (OR 1.28), and smokers (OR 4.67) and of Asian race (OR 2.12). L-NAFLD patients were more likely to have acute coronary syndromes (OR 30.00) and metabolic syndrome (OR 2.31) despite the normal/low BMI. Esophageal varices and hepatocellular carcinoma risks were high in both cirrhosis patients.

CONCLUSION

This is the largest study to assess L-NAFLD prevalence in the United States. L-NAFLD are at a significantly higher risk for acute coronary syndromes, esophageal varices, and hepatocellular carcinoma.

Lean or diabetic subtypes predict increased all-cause and disease-specific mortality in metabolic-associated fatty liver disease

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) encompasses diverse disease groups with potentially heterogeneous clinical outcomes. We investigated the risk of all-cause and disease-specific mortality in MAFLD subgroups.

METHODS

Using the Korean National Health Insurance Service database, participants were divided into four subgroups: no MAFLD, MAFLD-diabetes, MAFLD-overweight/obese, and MAFLD-lean. Hazard ratios (HRs) and 95% confidence interval (CI) values for all-cause and disease-specific mortality according to MAFLD subgroups were analyzed using Cox proportional hazards models.

RESULTS

Among 9,935,314 participants, those with MAFLD-diabetes showed the highest risk of all-cause and disease-specific mortality. The HRs (95% CI) for all-cause mortality were 1.61 (1.59-1.63), 1.36 (1.34-1.38), and 1.19 (1.18-1.20) in the MAFLD-diabetes, MAFLD-lean, and MAFLD-overweight/obese groups, respectively. The magnitude of cardiovascular disease and cancer-related risk showed the same pattern. The risk of liver-related mortality in the MAFLD-lean group (HR: 2.84, 95% CI: 2.72-2.97) was comparable with that in the MAFLD-diabetes group (HR: 2.85, 95% CI: 2.75-2.95). When stratified by body mass index, liver-related mortality was the highest in MAFLD-lean individuals in the underweight group (HR, 5.03, 95% CI: 4.23-5.97).

CONCLUSIONS

The MAFLD-lean and MAFLD-diabetes groups had a higher risk of all-cause and disease-specific mortality than did the MAFLD-overweight/obese group. Classifying MAFLD subgroups based on metabolic phenotypes might help risk stratification of patients with MAFLD.

Development and application of a novel model to predict the risk of non-alcoholic fatty liver disease among lean pre-diabetics with normal blood lipid levels

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has been associated with type 2 diabetes, but its relationship with pre-diabetes is still unknown. This study aims to determine whether pre-diabetes is associated with NAFLD, followed by establishing a NAFLD predictive nomogram for lean Chinese pre-diabetics with normal blood lipids.

METHODS

Datasets from 3 previous studies, 1 (2774 pre-diabetics with normal blood lipids for training, 925 for validation), 2 (546 for longitudinal internal validation, post-5-year follow-up), and 3 (501 from another institution for external validation), were used. Kaplan-Meier determined cumulative NAFLD hazard, and least absolute shrinkage and selection operator regression analysis uncovered its risk factors. Multivariate logistic regression analysis constructed the nomogram, followed by validation with receiver operating characteristic curve, calibration plot, and decision curve analyses.

RESULTS

NAFLD incidence increased with diabetes progression, and pre-diabetics had higher cumulative risk versus non-diabetics, even for lean individuals with normal blood lipids. Six risk factors were identified: body mass index, total cholesterol, alanine aminotransferase:aspartate aminotransferase, triglyceride:high density lipoprotein cholesterol, fasting blood glucose and γ-glutamyl-transferase. The nomogram yielded areas under the curve of 0.808, 0.785, 0.796 and 0.832, for respectively, training, validation, longitudinal internal validation, and external validation, which, along with calibration curve values of p = 0.794, 0.875, 0.854 and 0.810 for those 4 datasets and decision curve analyses, validated its clinical utility.

CONCLUSIONS

Lean pre-diabetic Chinese with normal blood lipids have higher NAFLD risk versus non-diabetics. The nomogram is able to predict NAFLD among such individuals, with high discrimination, enabling its use for early detection and intervention.

The Prevalence of Small Intestinal Bacterial Overgrowth in Patients with Non-Alcoholic Liver Diseases: NAFLD, NASH, Fibrosis, Cirrhosis-A Systematic Review, Meta-Analysis and Meta-Regression

Bacterial overgrowth in the small intestine (SIBO) is a pathological growth of the intestinal microbiota in the small intestine that causes clinical symptoms and can lead to digestive and absorption disorders. There is increasing evidence that people with NAFLD have a distinct gut microflora profile as well metabolome changes compared to people without NAFLD. Thorough analysis of observational and RCT studies in the current databases (EMBASE, Web of Science, PubMed, Cinahl, Clinical Trials) was conducted from 3 November 2021 to 21 June 2022. The following inclusion criteria were applied: confirmed NAFLD, NASH, LIVER FIBROSIS, CIRRHOSIS due to steatosis; diagnostic methods of liver diseases—biopsy, elastography, transabdominal ultrasound; nonalcoholic fatty liver disease activity score; confirmed SIBO; diagnostic methods of SIBO−breath tests (hydrogen test; methane test and mix test; duodenal and jejunal aspiration before any type of intervention; adults above 18yo; number of participants ≥20; full articles. We excluded review articles, populations with HBV/HCV infection and alcohol etiology and interventions that may affect NAFLD or SIBO treatment. The quality of each study methodology was classified by means of the Cochrane Collaboration’s tool (RCT) and Newcastle—Ottawa Quality Assessment Scale adapted for cross-sectional, cohort and case-control studies. The random effects meta-analysis of outcomes for which ≥2 studies contributed data was conducted. The I2 index to measure heterogeneity and the χ2 test of homogeneity (statistically significant heterogeneity p < 0.05) were applied. For categorical outcome, the pooled event rate (effect size) was calculated. This systematic review was reported according to PRISMA reporting guidelines. We initially identified 6643 studies, from which 18 studies were included in final meta-analysis. The total number of patients was 1263. Accepted SIBO diagnostic methods were both available breath tests (n-total = 15) and aspirate culture (n-total = 3). We found that among patients with non-alcoholic liver diseases, the random overall event rate of SIBO was 0.350 (95% CI, 0.244−0.472), p = 0.017. The subgroup analysis regarding a type of diagnosis revealed that the lowest ER was among patients who developed simultaneously NAFLD, NASH and fibrosis: 0.197 (95% CI, 0.054−0.510) as compared to other annotated subgroups. The highest prevalence of SIBO was observed in the NASH subgroup: 0.411 (95% CI, 0.219−0.634). There were no statistically significant differences in the prevalence of SIBO in different subgroups (p = 0.854). Statistically significant heterogeneity between studies was estimated (I2 = 86.17%, p = 0.00). Egger’s test did not indicate a publication bias (df = 16, p = 0.885). A meta-regression using a random-effects model revealed that higher percentage of males in the population with liver diseases is a predisposing factor toward SIBO (Q = 4.11, df = 1, p = 0.0426 with coefficient = 0.0195, SE = 0.0096, Z = 2.03). We showed that the prevalence of SIBO in patients with chronic non-alcoholic liver diseases can be as high as 35%, and it increases with the percentage of men in the population. The prevalence of SIBO does not differ significantly depending on the type of chronic liver disease. Despite the high heterogeneity and moderate and low quality of included studies, our meta-analysis suggests the existence of a problem of SIBO in the population of patients with non-alcoholic liver diseases, and the presence of SIBO, in turn, determines the therapeutic treatment of such type of patients, which indicates the need for further research in this area. The study protocol was registered with the international Prospective Register of Systematic Reviews (PROSPERO ID: CRD42022341473).

Pemafibrate therapy for non-alcoholic fatty liver disease is more effective in lean patients than obese patients

Introduction

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, with an increasing incidence. Pemafibrate is a novel selective peroxisome proliferator-activated receptor-a (PPAR-a) modulator which is expected to improve NAFLD. The aim of this study is to identify predictors of improvement of hepatic inflammation and fibrosis after pemafibrate therapy in patients with NAFLD.

Material and methods

Seventy-one non-diabetic patients with NAFLD treated with pemafibrate for more than six months were included in this retrospective review. Hepatic inflammation and fibrosis were evaluated by alanine aminotransferase (ALT) and Mac-2 binding protein glycosylation isomer (M2BPGi) levels, respectively.

Results

During six months of pemafibrate therapy, significant improvements were observed in ALT and M2BPGi levels regardless of the body mass index (BMI) compared to baseline. Lean NAFLD was identified as a significant positive predictor for > 50% reduction of ALT showing reduced hepatic inflammation. Subsequent multivariate analysis confirmed this result. Reduction of ALT in the lean NAFLD group (BMI < 25) was significantly greater than in the obese NAFLD group (BMI > 30) (p = 0.034). Lean NAFLD and age > 50 years were identified as significant positive predictors for > 20% reduction of M2BPGi showing reduced hepatic fibrosis. Subsequent multivariate analysis confirmed these results. Reduction of M2BPGi in the lean NAFLD group was significantly greater than in the obese NAFLD group (p = 0.022).

Conclusions

Pemafibrate therapy improves markers of hepatic inflammation and fibrosis regardless of BMI. Patients with lean NAFLD have a greater response to pemafibrate therapy compared to those with obese NAFLD.

Predictive Risk Factors of Nonalcoholic Fatty Liver Disease in a Lean Chinese Population

BACKGROUND

Although nonalcoholic fatty liver disease (NAFLD) is related to obesity, it may also affect lean individuals. Recent data suggest that lean NAFLD patients can develop the whole spectrum of NASH. However, the NAFLD predictive model for lean populations remains lacking.

METHODS

A total of 5037 lean individuals were included in this study, and the data were separated for training and validation. The logistic regression method was used, and a nomogram, a type of prediction model, was constructed according to the logistic regression analysis and the significant clinical factors. The performance of this model was evaluated based on its discrimination, calibration, and clinical utility.

RESULTS

The individuals were divided into the training (n = 4068) or validation (n = 969) cohorts at a ratio of 8 to 2. The overall prevalence of NAFLD in the lean cohort was 6.43%. The nomogram was constructed based on seven predictors: alanine aminotransferase, total cholesterol, triglycerides, low-density lipoprotein cholesterol, creatinine, uric acid, and hemoglobin A1C. The model based on these factors showed good predictive accuracy in the training set and in the internal validation set, with areas under the curve (AUCs) of 0.870 and 0.887, respectively. The calibration curves and decision curve analysis (DCA) displayed good clinical utility.

CONCLUSION

the nomogram model provides a simple and reliable ability to predict the risk of NAFLD in lean subjects. The model can predict lean NAFLD and can help physicians screen and identify lean subjects at a high risk of NAFLD.

The prevalence, comorbidities, influencing factors, and identifying factors of non-obese fatty liver disease

OBJECTIVE

To analyze the prevalence, associated comorbidities, influencing factors, and identifying factors of non-obese fatty liver disease and to provide a reference for its prevention and treatment.

MATERIALS AND METHODS

Firstly, to screen data obtained from the physical examinations of individuals conducted in the Second Affiliated Hospital of Xi'an Jiaotong University in 2021, subjects with complete data of abdominal ultrasonography, body mass index, age and sex were selected to analyze the prevalence of fatty liver disease and non-obese fatty liver disease. Secondly, to screen non-obese subjects who had data for triglycerides, fasting blood glucose, and so on, to analyze the complications, influencing factors, and identifying factors of non-obese fatty liver disease.

RESULTS

The prevalence of fatty liver disease was 27.8% (18,416/66,221), including 33.9% (11,921/35,131) in males and 20.9% (6,495/31,090) in females, revealing that the prevalence was significantly higher in males than in females (P < 0.001). There were 40,673 non-obese subjects screened in total, and the prevalence of non-obese fatty liver disease was 13.0% (5,307/40,673). The prevalence of non-obese fatty liver disease was 13.3% (2,208/16,572) in males and 12.9% (3,099/24,101) in females; the difference was not statistically significant (P = 0.17). The serum triglycerides level was elevated in 54.2% of subjects with non-obese fatty liver disease, and this was the most common abnormal metabolic index accompanying the disease. Logistic regression analysis showed that gender, age, body mass index, blood pressure, alanine aminotransferase, aspartate aminotransferase, fasting blood glucose, triglycerides, total cholesterol, and serum uric acid were independent risk factors for non-obese fatty liver disease (P < 0.001). For triglycerides, the area under the receiver operating characteristic curve in predicting non-obese fatty liver disease was the greatest (0.806).

CONCLUSION

The prevalence of fatty liver disease and non-obese fatty liver disease determined by the physical examination of individuals was high, and the triglycerides is likely to be useful for the extensive screening of non-obese fatty liver disease.

Differences in Insulin Sensitivity, Secretion, and the Metabolic Clearance Rate of Glucose in Newly Diagnosed Type 2 Diabetes Mellitus Patients: The Influences of Body Mass Index and Fatty Liver

Background: Obesity and nonalcoholic fatty liver disease are strongly associated with type 2 diabetes mellitus (T2DM), affecting insulin sensitivity and β-cell function. They interact, exacerbating the development of hyperinsulinemia to T2DM. Methods: Through oral glucose tolerance and insulin secretion tests, the relationships between insulin sensitivity and secretion, glucose clearance, body mass index (BMI), and fatty liver were studied in newly diagnosed T2DM patients. The homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of β-cell function (HOMA-β), insulin sensitivity index (ISI), and metabolic clearance rate (MCR) of glucose were calculated to analyze insulin sensitivity and β-cell function. Results: There were no differences in HOMA-IR, HOMA-β, first-phase insulin secretion (1st PH), second-phase insulin secretion (2nd PH), ISI, or MCR between lean fatty liver and lean nonfatty liver patients. Both overweight/obesity (ow/ob) and patients with fatty liver increased HOMA-IR, and decreased ISI and MCR. In the ow/ob subgroup, patients with fatty liver had severe insulin resistance but greater HOMA-β, 1st PH, and 2nd PH than individuals with nonfatty liver. The difference in MCR between fatty liver and nonfatty liver groups was not significant. Conclusion: BMI and hepatic steatosis are independent determinants of increased insulin resistance and decreased MCR. However, it is steatosis, not BMI, related to the increase in insulin secretion.

RISK FACTORS FOR HEPATOCELLULAR CARCINOMA IN PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE

Non-alcoholic fatty liver disease is growing in worldwide prevalence and thus, is expected to have a higher number of NAFLD-related hepatocellular carcinoma (HCC) in the following years. This review describes the risk factors associated with HCC in NAFLD-patients. The presence of liver cirrhosis is the preponderant one. Male gender, PNPLA3 variants, diabetes, and obesity also appear to predispose to the development of HCC, even in non-cirrhotic subjects. Thus far, intensive lifestyle modifications, including glycemic control, and obesity treatment, are effective therapies for NAFLD/ non-alcoholic steatohepatitis and, therefore, probably, also for HCC. Some drugs that aimed at decreasing inflammatory activity and fibrosis, as well as obesity, were studied. Other data have suggested the possibility of HCC chemoprevention. So far, however, there is no definitive evidence for the routine utilization of these drugs. We hope, in the future, to be able to profile patients at higher risk of NAFLD-HCC and outline strategies for early diagnosis and prevention.