Nonalcoholic fatty liver disease: cause or consequence of type 2 diabetes?

Diabetes mellitus-Progress and opportunities in the evolving epidemic

Diabetes, a complex multisystem metabolic disorder characterized by hyperglycemia, leads to complications that reduce quality of life and increase mortality. Diabetes pathophysiology includes dysfunction of beta cells, adipose tissue, skeletal muscle, and liver. Type 1 diabetes (T1D) results from immune-mediated beta cell destruction. The more prevalent type 2 diabetes (T2D) is a heterogeneous disorder characterized by varying degrees of beta cell dysfunction in concert with insulin resistance. The strong association between obesity and T2D involves pathways regulated by the central nervous system governing food intake and energy expenditure, integrating inputs from peripheral organs and the environment. The risk of developing diabetes or its complications represents interactions between genetic susceptibility and environmental factors, including the availability of nutritious food and other social determinants of health. This perspective reviews recent advances in understanding the pathophysiology and treatment of diabetes and its complications, which could alter the course of this prevalent disorder.

Maternal obesity and metabolic (dysfunction) associated fatty liver disease in pregnancy: a comprehensive narrative review

INTRODUCTION

Obesity and metabolic-associated fatty liver disease (MAFLD) during pregnancy constitute significant problems for routine antenatal care, with increasing prevalence globally. Similar to obesity, MAFLD is associated with a higher risk for maternal complications (e.g. pre-eclampsia and gestational diabetes) and long-term adverse health outcomes for the offspring. However, MAFLD during pregnancy is often under-recognized, with limited management/treatment options.

AREAS COVERED

PubMed/MEDLINE, EMBASE, and Scopus were searched based on a search strategy for obesity and/or MAFLD in pregnancy to identify relevant papers up to 2024. This review summarizes the pertinent evidence on the relationship between maternal obesity and MAFLD during pregnancy. Key mechanisms implicated in the underlying pathophysiology linking obesity and MAFLD during pregnancy (e.g. insulin resistance and dysregulated adipokine secretion) are highlighted. Moreover, a diagnostic approach for MAFLD diagnosis during pregnancy and its complications are presented. Finally, promising relevant areas for future research are covered.

EXPERT OPINION

Research progress regarding maternal obesity, MAFLD, and their impact on maternal and fetal/offspring health is expected to improve the relevant diagnostic methods and lead to novel treatments. Thus, routine practice could apply more personalized management strategies, incorporating individualized algorithms with genetic and/or multi-biomarker profiling to guide prevention, early diagnosis, and treatment.

Impact of clonal hematopoiesis of indeterminate potential on hepatocellular carcinoma in individuals with steatotic liver disease

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global epidemic and is the most rapidly rising cause of HCC. Clonal hematopoiesis of indeterminate potential (CHIP) contributes to neoplastic and cardiometabolic disorders and is considered a harbinger of tissue inflammation. CHIP was recently associated with increased risk of liver disease. The aim of this study was to examine whether CHIP is associated with HCC development in patients with SLD.

APPROACH AND RESULTS

We considered individuals with MASLD-HCC (n=208) and controls with (n =414) and without (n =259) advanced fibrosis who underwent whole exome sequencing. CHIP was diagnosed when ≥2 variant callers identified a known myeloid mutation with variant allele frequency ≥2%. CHIP was observed in 116 participants (13.1%), most frequently in DNMT3A, TET2, TP53 , and ASXL1 , and correlated with age ( p <0.0001) and advanced liver fibrosis (p=0.001). Higher aspartate aminotransferase levels predicted non- DNMT3A -CHIP, in particular with variant allele frequency ≥10% (OR: 1.14, 1.03 -1.28 and OR: 1.30, 1.12 -1.49, respectively, p <0.05). After adjustment for sex, diabetes, and a polygenic risk, a score of inherited MASLD predisposition CHIP was associated with cirrhosis (2.00, 1.30 -3.15, p =0.02), and with HCC even after further adjustment for cirrhosis (OR: 1.81, 1.11 -2.00, 1.30 -3.15, p =0.002). Despite the strong collinearity among aging and development of CHIP and HCC, non- DNTM3A -CHIP, and TET2 lesions remained associated with HCC after full correction for clinical/genetics covariates and age (OR: 2.45, 1.35 -4.53; OR: 4.8, 1.60 -17.0, p =0.02).

CONCLUSIONS

We observed an independent association between CHIP, particularly related to non- DNTM3A and TET2 genetic lesions and MASLD-HCC.

Oxidative Balance Score and New-Onset Type 2 Diabetes Mellitus in Korean Adults without Non-Alcoholic Fatty Liver Disease: Korean Genome and Epidemiology Study-Health Examinees (KoGES-HEXA) Cohort

The oxidative balance score (OBS) is a novel composite of pro- and anti-oxidative markers for assessing the risk of cardiometabolic diseases and non-alcoholic fatty liver disease (NAFLD). However, it has not yet been established whether the OBS is related to type 2 diabetes mellitus (T2DM), especially in a population without NALFD. Therefore, we aimed to investigate the longitudinal effect of the OBS on T2DM in a large cohort of Korean adults without NALFD. Data were assessed from 9798 participants without NALFD from the Korean Genome and Epidemiology Study-Health Examinees (KoGES-HEXA) cohort. The participants were divided into three groups according to OBS tertiles, identified as T1-T3. We prospectively assessed the hazard ratios (HRs) with 95% confidence intervals (CIs) for new-onset T2DM using multivariable Cox proportional hazard regression models over 6 years following the baseline survey. During the mean 3.5 years of follow-up, 145 individuals (1.48%; 56 men and 89 women) developed T2DM. The HRs of T2DM for the OBS tertiles were 0.79 (95% CI, 0.53-1.18) and 0.60 (95% CI, 0.39-0.93) in the T2 and T3 groups after adjusting for metabolic parameters in subjects without NALFD, respectively; however, the T2 group did not show statistical significance toward a decrease in incident T2DM. A low OBS may be a useful predictive marker in new-onset T2DM for middle-aged and older subjects without NALFD. This implies that the OBS could be an additional valuable tool for assessing the incidence of T2DM among individuals without NAFLD.

Nutritional Interventions, Probiotics, Synbiotics and Fecal Microbiota Transplantation in Steatotic Liver Disease : Pediatric Fatty Liver and Probiotics

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major health problem worldwide, and the strongest determinant of liver disease in children. The possible influence of high-fat/low-fiber dietary patterns with microbiota (e.g., increased Firmicutes/Bacteroidetes ratio), and ultimately with MASLD occurrence and progression has been elucidated by several association studies. The possible mechanisms through which microbes exert their detrimental effects on MASLD include gut vascular barrier damage, a shift towards non-tolerogenic immunologic environment, and the detrimental metabolic changes, including a relative reduction of propionate and butyrate in favor of acetate, endogenous ethanol production, and impairment of the unconjugated bile acid-driven FXR-mediated gut-liver axis. The impact of nutritional and probiotic interventions in children with MASLD is described.

Liver fat as risk factor of hepatic and cardiometabolic diseases

Non-alcoholic fatty liver disease (NAFLD) is a disorder characterized by excessive accumulation of fat in the liver that can progress to liver inflammation (non-alcoholic steatohepatitis [NASH]), liver fibrosis, and cirrhosis. Although most efforts for drug development are focusing on the treatment of the latest stages of NAFLD, where significant fibrosis and NASH are present, findings from studies suggest that the amount of liver fat may be an important independent risk factor and/or predictor of development and progression of NAFLD and metabolic diseases. In this review, we first describe the current tools available for quantification of liver fat in humans and then present the clinical and pathophysiological evidence that link liver fat with NAFLD progression as well as with cardiometabolic diseases. Finally, we discuss current pharmacological and non-pharmacological approaches to reduce liver fat and present open questions that have to be addressed in future studies.

Mendelian randomization explores the causal relationships between obesity, diabetes, inflammation and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. Observational studies have revealed various risk factors associated with NAFLD, while the causal relationships between NAFLD and clinical diseases (including obesity, diabetes and inflammation) remain unclear. In this study, based on the genome-wide association study (GWAS) data, a two-sample Mendelian randomization (MR) analysis was conducted to evaluate the causality between NAFLD and 6 clinical indicators, including body mass index (BMI), waist-to-hip ratio (WHR), C-reactive protein (CRP), fasting blood glucose (FG), fasting insulin (FI), and glycosylated hemoglobin (HbA1c). MR is based on Mendel's law of inheritance, which uses genetic variation as a toll variable to affect the health of a population to infer causal effects in the presence of unobserved confounding. Inverse variance weighted method was the main MR method. In addition, we performed multiple steps of variable screening in the method to ensure that we were conducting the study under the MR assumption. In the MR analysis, a higher WHR (P = .0078; OR = 1.008; 95% CI, 1.002-1.013) was genetically predicted to be causally associated with an increased risk of NAFLD, while patients with higher HbA1c had a lower risk of NAFLD (P = .0437; OR = 0.44; 95% CI, 0.20-0.97). Our results showed that the genetically driven WHR and HbA1c might be potential causal factors for NAFLD, while BMI, FG, FI, and CRP were not causal factors for NAFLD, which explained the promoting role of WHR and HbA1c in the occurrence and development of NAFLD. Our finding hence revealed new insights into how nature and nurture factors underpin NAFLD, providing positive effect on the causes and prevention of this disease.

Genetic predisposition to nonalcoholic fatty liver disease: insights from ANGPTL8 gene variants in Iranian adults

Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease with a global prevalence, and modulation of ANGPTL8 expression has emerged as a promising predictor of NAFLD susceptibility. This research was conducted to scrutinize ANGPTL8 protein expression in NAFLD patients and elucidate the interplay between ANGPTL8 gene polymorphisms and their lipid profiles, thus shedding new light on the pathophysiology of this complex disease. The study comprised 423 unrelated participants, including 222 healthy controls and 201 individuals with NAFLD, screened using FibroScan/ultrasonography and laboratory tests. The main goal focused on the genotype and allele frequency distribution in the ANGPTL8 gene, specifically analyzing two genetic variations: rs737337 (T/C) and rs2278426 (C/T). The participants diagnosed with NAFLD were slightly younger (P ≥ 0.05) and had a higher body mass index (BMI) than the individuals in the control group. Notably, there was a significant difference in the occurrence of the rs737337 polymorphism between the NAFLD and control groups, with a lower frequency observed in the NAFLD group. Our results indicated that individuals with the TC + CC genotype and C allele of rs737337 (T/C) had a decreased risk of higher levels of ALT and AST. Conversely, those with the CT, CT + TT genotype, and T allele of rs2278426 (C/T) exhibited an increased risk of higher levels of ALT and AST. The results imply that the rs2278426 (C/T) variant of the ANGPTL8 gene is more strongly linked to an increased risk of NAFLD compared to the rs737337 polymorphism. However, additional research is needed to understand the specific molecular mechanisms responsible for the upregulation of ANGPTL8 in individuals with NAFLD.

Type 2 Diabetes Mellitus, Non-Alcoholic Fatty Liver Disease, and Metabolic Repercussions: The Vicious Cycle and Its Interplay with Inflammation

The prevalence of metabolic-related disorders, such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (DM2), has been increasing. Therefore, developing improved methods for the prevention, treatment, and detection of these two conditions is also necessary. In this study, our primary focus was on examining the role of chronic inflammation as a potential link in the pathogenesis of these diseases and their interconnections. A comprehensive search of the PubMed database using keywords such as "non-alcoholic fatty liver disease", "type 2 diabetes mellitus", "chronic inflammation", "pathogenesis", and "progression" yielded 177 relevant papers for our analysis. The findings of our study revealed intricate relationships between the pathogenesis of NAFLD and DM2, emphasizing the crucial role of inflammatory processes. These connections involve various molecular functions, including altered signaling pathways, patterns of gene methylation, the expression of related peptides, and up- and downregulation of several genes. Our study is a foundational platform for future research into the intricate relationship between NAFLD and DM2, allowing for a better understanding of the underlying mechanisms and the potential for introducing new treatment standards.

Type 2 Diabetes Mellitus and Liver Disease: Across the Gut-Liver Axis from Fibrosis to Cancer

Type 2 diabetes mellitus is a widespread disease worldwide, and is one of the cornerstones of metabolic syndrome. The existence of a strong relationship between diabetes and the progression of liver fibrosis has been demonstrated by several studies, using invasive and noninvasive techniques. Patients with type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD) show faster progression of fibrosis than patients without diabetes. Many confounding factors make it difficult to determine the exact mechanisms involved. What we know so far is that both liver fibrosis and T2DM are expressions of metabolic dysfunction, and we recognize similar risk factors. Interestingly, both are promoted by metabolic endotoxemia, a low-grade inflammatory condition caused by increased endotoxin levels and linked to intestinal dysbiosis and increased intestinal permeability. There is broad evidence on the role of the gut microbiota in the progression of liver disease, through both metabolic and inflammatory mechanisms. Therefore, dysbiosis that is associated with diabetes can act as a modifier of the natural evolution of NAFLD. In addition to diet, hypoglycemic drugs play an important role in this scenario, and their benefit is also the result of effects exerted in the gut. Here, we provide an overview of the mechanisms that explain why diabetic patients show a more rapid progression of liver disease up to hepatocellular carcinoma (HCC), focusing especially on those involving the gut-liver axis.

The effect of G0S2 on insulin sensitivity: A proteomic analysis in a G0S2-overexpressed high-fat diet mouse model

BACKGROUND

Previous research has shown a tight relationship between the G0/G1 switch gene 2 (G0S2) and metabolic diseases such as non-alcoholic fatty liver disease (NAFLD) and obesity and diabetes, and insulin resistance has been shown as the major risk factor for both NAFLD and T2DM. However, the mechanisms underlying the relationship between G0S2 and insulin resistance remain incompletely understood. Our study aimed to confirm the effect of G0S2 on insulin resistance, and determine whether the insulin resistance in mice fed a high-fat diet (HFD) results from G0S2 elevation.

METHODS

In this study, we extracted livers from mice that consumed HFD and received tail vein injections of AD-G0S2/Ad-LacZ, and performed a proteomics analysis.

RESULTS

Proteomic analysis revealed that there was a total of 125 differentially expressed proteins (DEPs) (56 increased and 69 decreased proteins) among the identified 3583 proteins. Functional enrichment analysis revealed that four insulin signaling pathway-associated proteins were significantly upregulated and five insulin signaling pathway -associated proteins were significantly downregulated.

CONCLUSION

These findings show that the DEPs, which were associated with insulin resistance, are generally consistent with enhanced insulin resistance in G0S2 overexpression mice. Collectively, this study demonstrates that G0S2 may be a potential target gene for the treatment of obesity, NAFLD, and diabetes.

Comparison of MAFLD and NAFLD Characteristics in Children

Background & aims: An international panel proposed a diagnostic framework for metabolic-associated fatty liver disease (MAFLD) in children. The aim was to compare the clinical features of MAFLD and nonalcoholic fatty liver disease (NAFLD) in children. Methods: The characteristic differences between NAFLD and MAFLD in children were compared with the National Health and Nutrition Examination Survey (NHANES) 2017–2018 in the U.S. and the Comprehensive Prevention Project for Overweight and Obese Adolescents (CPOOA) study in China. Results: In NHANES 2017–2018, regardless of which criteria were implemented, participants with hepatic steatosis were more likely to have higher BMI z-scores, a higher prevalence of hypertension or higher metabolic indices and higher non-invasive liver fibrosis scores (all p < 0.05). The cases diagnosed by those two definitions had a similarity of over 75%. More obese children were diagnosed with MAFLD than NAFLD (p < 0.001). However, approximately 19% of children with NAFLD present with normal weight and fasting glucose levels and cannot be diagnosed with MAFLD. The CPOOA study excluded viral infected liver disease and certain kinds of congenital causes of liver steatosis patients, resulting in children with NAFLD being identical with MAFLD children. Conclusions: Most clinical features were similar between children with MAFLD and children with NAFLD, and more than 75% of children with NAFLD can also be diagnosed with MAFLD. However, approximately 19% of children with NAFLD cannot be categorized as MAFLD. Therefore, to gain greater benefits from renaming NAFLD to MAFLD in pediatrics, the prevalence of different causes of hepatic steatosis in children needs to be understood.

Risk Factors of Non-alcoholic Fatty Liver Disease in the Iranian Adult Population: A Systematic Review and Meta-analysis

Context: Non-alcoholic fatty liver disease (NAFLD) is progressing considerably worldwide. Identifying the risk factors of NAFLD is a critical step in preventing its progression. Methods: In November 2022, two independent researchers studied seven databases, including PubMed, ISI/WoS, ProQuest, Scopus, SID, Magiran, and Google Scholar, and reference list of relevant articles, searching studies that assessed NAFLD risk factors in the Iranian adult population. Heterogeneity between studies was assessed by Cochran’s test and its composition using I2 statistics. A random-effects model was used when heterogeneity was observed; otherwise, a fixed-effects model was applied. Egger’s regression test and Trim-and-Fill analysis were used to assess publication bias. Comprehensive Meta-analysis software (version 3) was used for the analyses of the present study. Results: The results of this study showed significant associations between NAFLD with age [n = 15, odds ratio (OR) = 2.12, 95% CI: 1.79 - 2.51], body mass index (n = 46, OR = 5.00, 95% CI: 3.34 - 7.49), waist circumference (n = 20, OR = 6.37, 95% CI: 3.25 - 12.48), waist-to-hip ratio (n = 17, OR = 4.72, 95% CI: 3.93 - 5.66), total cholesterol (n = 39, OR = 1.80, 95% CI: 1.52 - 2.13), high-density lipoprotein (n = 37, OR = 0.53, 95% CI: 0.44 - 0.65), low-density lipoprotein (n = 31, OR = 1.68, 95% CI: 1.38 - 2.05), triglyceride (n = 31, OR = 3.21, 95% CI: 2.67 - 3.87), alanine aminotransferase (n = 26, OR = 4.06, 95% CI: 2.94 - 5.62), aspartate aminotransferase (n = 27, OR = 2.16, 95% CI: 1.50 - 3.12), hypertension (n = 13, OR = 2.53, 95% CI: 2.32 - 2.77), systolic blood pressure (n = 13, OR = 1.83, 95% CI: 1.53 - 2.18), diastolic blood pressure (n = 14, OR = 1.80, 95% CI: 1.48 - 2.20), fasting blood sugar (n = 31,OR = 2.91, 95% CI: 2.11- 4.01), homeostatic model assessment for insulin resistance (n = 5, OR = 1.92, 95% CI: 1.48 - 2.59), diabetes mellitus (n = 15, OR = 3.04, 95% CI: 2.46 - 3.75), metabolic syndrome (n = 10, OR = 3.56, 95% CI: 2.79 - 4.55), and physical activity (n = 11, OR = 0.32, 95% CI: 0.24 - 0.43) (P < 0.05). Conclusions: In conclusion, several factors are significantly associated with NAFLD. However, anthropometric indices had the strongest relationship with NAFLD in the Iranian adult population.

Hepatocyte Kctd17 Inhibition Ameliorates Glucose Intolerance and Hepatic Steatosis Caused by Obesity-induced Chrebp Stabilization

BACKGROUND & AIMS

Obesity predisposes to type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD), but underlying mechanisms are incompletely understood. Potassium channel tetramerization domain-containing protein 17 (Kctd17) levels are increased in livers from obese mice and humans. In this study, we investigated the mechanism of increased Kctd17 and whether it is causal to obesity-induced metabolic complications.

METHODS

We transduced Rosa26-LSL-Cas9 knockin mice with AAV8-TBG-Cre (Control), AAV8-U6-Kctd17 sgRNA-TBG-Cre (L-Kctd17), AAV8-U6-Oga sgRNA-TBG-Cre (L-Oga), or AAV8-U6-Kctd17/Oga sgRNA-TBG-Cre (DKO). We fed mice a high-fat diet (HFD) and assessed for hepatic glucose and lipid homeostasis. We generated Kctd17, O-GlcNAcase (Oga), or Kctd17/Oga-knockout hepatoma cells by CRISPR-Cas9, and Kctd17-directed antisense oligonucleotide to test therapeutic potential in vivo. We analyzed transcriptomic data from patients with NAFLD.

RESULTS

Hepatocyte Kctd17 expression was increased in HFD-fed mice due to increased Srebp1c activity. HFD-fed L-Kctd17 or Kctd17 antisense oligonucleotide-treated mice show improved glucose tolerance and hepatic steatosis, whereas forced Kctd17 expression caused glucose intolerance and hepatic steatosis even in lean mice. Kctd17 induced Oga degradation, resulting in increasing carbohydrate response element-binding protein (Chrebp) protein, so concomitant Oga knockout negated metabolic benefits of hepatocyte Kctd17 deletion. In patients with NAFLD, KCTD17 messenger RNA was positively correlated with expression of Chrebp target and other lipogenic genes.

CONCLUSIONS

Srebp1c-induced hepatocyte Kctd17 expression in obesity disrupted glucose and lipid metabolism by stabilizing Chrebp, and may represent a novel therapeutic target for obesity-induced T2D and NAFLD.

Liver fat is superior to visceral and pancreatic fat as a risk biomarker of impaired glucose regulation in overweight/obese subjects

AIM

To investigate the distribution of abdominal fat, particularly ectopic fat accumulation, in relation to glucose metabolism in overweight/obese patients.

MATERIALS AND METHODS

This study included 257 overweight/obese subjects with body mass index ≥23 kg/m² . All the subjects underwent an oral glucose tolerance test. Magnetic resonance imaging-proton density fat fraction was used to measure fat accumulation in the liver, pancreas and abdomen. Impaired glucose regulation (IGR) was defined as the presence of prediabetes or diabetes.

RESULTS

Liver fat content (LFC) and visceral adipose tissue (VAT) were higher in overweight/obese subjects with diabetes than in those with normal glucose tolerance (NGT). No significant differences were observed in the pancreas fat content and subcutaneous fat area between subjects with NGT and IGR. LFC was an independent risk factor of IGR (odds ratio = 1.824 per standard deviation unit, 95% CI 1.242-2.679, p = .002). Compared with the lowest tertile of LFC, the multivariate-adjusted odds ratio for the prevalence of IGR in the highest tertile was 2.842 (95% CI 1.205-6.704). However, no association was observed between the VAT per standard deviation increment and tertiles after adjusting for multiple factors. For discordant visceral and liver fat phenotypes, the high LFC-low VAT and high LFC-high VAT groups had a higher prevalence of IGR than the low LFC-low VAT group. However, there was no difference in the prevalence of IGR between the low LFC-low VAT and low LFC-high VAT groups.

CONCLUSION

Compared with visceral and pancreatic fat content, LFC is a superior risk biomarker for IGR in overweight/obese subjects.

Understanding NAFLD: From Case Identification to Interventions, Outcomes, and Future Perspectives

While non-alcoholic fatty liver disease (NAFLD) is a prevalent and frequent cause of liver-related morbidity and mortality, it is also strongly associated with cardiovascular disease-related morbidity and mortality, likely driven by its associations with insulin resistance and other manifestations of metabolic dysregulation. However, few satisfactory pharmacological treatments are available for NAFLD due in part to its complex pathophysiology, and challenges remain in stratifying individual patient's risk for liver and cardiovascular disease related outcomes. In this review, we describe the development and progression of NAFLD, including its pathophysiology and outcomes. We also describe different tools for identifying patients with NAFLD who are most at risk of liver-related and cardiovascular-related complications, as well as current and emerging treatment options, and future directions for research.

The crucial role and mechanism of insulin resistance in metabolic disease

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

Exosomes from Short-Term High-Fat or High-Sucrose Fed Mice Induce Hepatic Steatosis through Different Pathways

Obesity and other closely associated diseases, such as metabolic-associated fatty liver disease (MAFLD) and type 2 diabetes, give rise to a common biometric and metabolic phenotype resulting from a different etiopathogenesis. To characterize the first stages of metabolic dysfunction induced by either obesity or hepatic steatosis, we compared two animal models of short-term feeding with either high-fat (HFD) or high-sucrose (SAC) diets. Using transcriptomic, metabolic, and calorimetric analyses, we determined that a short-term HFD leads to obesity and then hepatic steatosis through lipid storage, whereas SAC increases gluconeogenesis and de novo lipogenesis, resulting in hepatic steatosis followed later by obesity. Plasma exosomal miRNA profiles differed between HFD and SAC mice, and the injection of exosomes from HFD or SAC mice reproduced some transcriptomic and metabolic features of the donor mice. Finally, we exploited our data to identify circulating miR-22-3p as a candidate biomarker for MAFLD patient stratification. In conclusion, dietary challenges affecting adipose or hepatic metabolism regulate the abundance of exosomal miRNAs in plasma, which in turn modulate gene expression, helping the organism to adapt.

Lactobacillus sakei MJM60958 as a Potential Probiotic Alleviated Non-Alcoholic Fatty Liver Disease in Mice Fed a High-Fat Diet by Modulating Lipid Metabolism, Inflammation, and Gut Microbiota

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease with a rapidly increasing number of cases worldwide. This study aimed to evaluate the effects of Lactobacillus sakei MJM60958 (MJM60958) on NAFLD in vitro and in vivo. In in vitro tests, MJM60958 significantly inhibited lipid accumulation by 46.79% in HepG2 cells stimulated with oleic acid and cholesterol (OA-C). Moreover, MJM60958 showed safe and probiotic characteristics in vitro. In the animal study, MJM60958 administration in a high-fat diet-induced NAFLD mouse model significantly reduced body weight and liver weight, and controlled aspartate aminotransferase (ALT), aspartate transaminase (AST), triglyceride (TG), urea nitrogen (BUN), and uric acid (UA) levels in the blood, which are features of NAFLD. Further, treatment with MJM60958 also reduced steatosis scores in liver tissues, serum leptin and interleukin, and increased serum adiponectin content. Moreover, administration of MJM60958 resulted in a significantly decreased expression of some genes and proteins which are related to lipid accumulation, such as fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and sterol regulatory element-binding protein 1 (SREBP-1), and also upregulated genes and protein expression of lipid oxidation such as peroxisome proliferator-activated receptor alpha (PPARα) and carnitine palmitoyltransferase 1a (CPT1A). Administration of MJM60958 increased the relative abundance of specific microbial taxa such as Verrucomicrobia, which are abundant in non-NAFLD mice, and reduced Firmicutes, which are a major group in NAFLD mice. MJM60958 affected the modulation of gut microbiota and altered the strain profile of short-chain fatty acids (SCFAs) production in the cecum by reduced lactic acid and enhanced acetic acid production. Overall, MJM60958 showed potential as a probiotic that can prevent and treat NAFLD.

Pregnancy and Metabolic-associated Fatty Liver Disease: A Clinical Update

The intricate relationship between metabolic-associated fatty liver disease (MAFLD) and maternal complications has rapidly become a significant health threat in pregnant women. The presence of MAFLD in pregnancy increases the maternal risk of metabolic complications and comorbidities for both mother and baby. The preexistence or development of MAFLD in pregnancy is a complex multifactorial disorder that can lead to further complications for mother and baby. Therefore, as pregnant women are severely underrepresented in clinical research, there is a great need for a fair inclusion of this group in clinical trials. This review aims to explore the effects of MAFLD during pregnancy in the context of maternal complications and outcomes and explore the effects of pregnancy on the development and progression of MAFLD within the context of maternal obesity, altered metabolic profiles, gestational diabetes and altered hormonal profiles. We also addressed potential implications for the presence of MAFLD during pregnancy and its management in the clinical setting.

Metabolic dysfunction-associated fatty liver disease in obese youth with insulin resistance and type 2 diabetes

PURPOSE OF REVIEW

The aim of this review is to present the new definition of the disease, defining the epidemiology, risk factors with a particular attention to the role of insulin resistance (IR) and to define the main treatments explored.

RECENT FINDINGS

Nonalcoholic fatty liver disease (NAFLD) was previously considered a primary liver disease, but it would be more correct to consider it a component of the metabolic syndrome (MetS) in which IR might play a key role. Based on these findings, it has been recently proposed to modify the classic term of NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) that better reflects the pathophysiology of this complex disease.

SUMMARY

Currently, no treatments approved in childhood are available, thus the only recommended approach is the prevention and correction of the known risk factors, and particularly of IR. However, further studies are needed to better clarify the pathogenetic mechanisms of NAFLD in order to establish more tailored therapies.

Simultaneously Screening for Liver Steatosis and Fibrosis in Romanian Type 2 Diabetes Mellitus Patients Using Vibration-Controlled Transient Elastography with Controlled Attenuation Parameter

Non-alcoholic fatty liver disease (NAFLD) is a common finding among patients with type 2 diabetes mellitus (T2DM). Between NAFLD and T2DM exist a bidirectional relationship. Patients with T2DM are at high risk for NAFLD, and evidence suggests that T2DM is linked to progressive NAFLD and poor liver outcomes. NAFLD promotes the development of T2DM and leads to a substantial increase in the risk of T2DM complications. This study aimed to assess the prevalence of liver steatosis and fibrosis in patients with T2DM from north-eastern Romania by using Vibration-Controlled Transient Elastography (VCTE) with Controlled Attenuation Parameter (CAP), which is a non-invasive method and can assess simultaneously liver steatosis and fibrosis. In total, 424 consecutive patients with T2DM were enrolled and evaluated using VCTE with CAP from January 2020 to January 2022. Clinical and laboratory data were recorded in all patients. For the CAP score, we used the following cut-offs: mild steatosis (S1)—274 dB/m, moderate steatosis (S2)—290 dB/m, and severe steatosis (S3)—302 dB/m. For liver fibrosis, to differentiate between fibrosis stages, the cut-off values were F ≥ 8.2 kPa for significant fibrosis (F2), F ≥ 9.7 kPa for advanced fibrosis (F3), and F ≥ 13.6 kPa for cirrhosis (F4). In total, 380 diabetic patients (72.6%) had liver steatosis (51.3% females, the mean age of 55.22 ± 10.88 years, mean body mass index (BMI) 29.12 ± 5.64 kg/m2). Among them, 26 (8.4%) patients had moderate liver steatosis (S2) and 242 (78.5%) patients had severe hepatic steatosis (S3). According to VCTE measurements, 176 (57.14%) patients had liver fibrosis, 36 (11.7%) of them had advanced fibrosis (F3), and 42 (13.6%) diabetic patients had cirrhosis (F4). Univariate analyses showed that severe steatosis was significantly associated with ferritin (β = 0.223, p = 0.022), total cholesterol (β = 0.159, p = 0.031), and HDL-cholesterol (β = −0.120, p = 0.006). In multivariate analyses, BMI (β = 0.349, p < 0.001), fasting plasma glucose (β = 0.211, p = 0.006), and triglycerides (β = 0.132, p = 0.044) were predictors of S3. Patients with T2DM have a high prevalence of severe steatosis and advanced fibrosis which can lead to the development and progression of complications with high morbidity and mortality rates. Hence, it is necessary to implement screening strategies to prevent advanced liver disease in patients with T2DM.

NADPH Oxidases Connecting Fatty Liver Disease, Insulin Resistance and Type 2 Diabetes: Current Knowledge and Therapeutic Outlook

Nonalcoholic fatty liver disease (NAFLD), characterized by ectopic fat accumulation in hepatocytes, is closely linked to insulin resistance and is the most frequent complication of type 2 diabetes mellitus (T2DM). One of the features connecting NAFLD, insulin resistance and T2DM is cellular oxidative stress. Oxidative stress refers to a redox imbalance due to an inequity between the capacity of production and the elimination of reactive oxygen species (ROS). One of the major cellular ROS sources is NADPH oxidase enzymes (NOX-es). In physiological conditions, NOX-es produce ROS purposefully in a timely and spatially regulated manner and are crucial regulators of various cellular events linked to metabolism, receptor signal transmission, proliferation and apoptosis. In contrast, dysregulated NOX-derived ROS production is related to the onset of diverse pathologies. This review provides a synopsis of current knowledge concerning NOX enzymes as connective elements between NAFLD, insulin resistance and T2DM and weighs their potential relevance as pharmacological targets to alleviate fatty liver disease.

Impact of non-alcoholic fatty liver disease on the risk of sarcopenia: a nationwide multicenter prospective study

BACKGROUND AND AIMS

Despite the association between sarcopenia and non-alcoholic fatty liver disease (NAFLD), no study has evaluated the predictive role of NAFLD in sarcopenia. We investigated impact of NAFLD on the risk of low muscle mass (LMM) and low muscle strength (LMS) in a nationwide multicenter study.

METHODS

A total of 1595 community-dwelling people aged 70-84 years were followed for 2 years in the Korean Frailty and Aging Cohort Study. Muscle mass was estimated by dividing appendicular skeletal muscle mass (ASM) by body mass index (BMI). Muscle strength was measured as handgrip strength (HGS) divided by BMI. The sex-specific lowest quintiles of ASM/BMI and HGS/BMI of the study population were used as cutoffs for LMM and LMS, respectively. The risk of LMM and LMS were assessed according to hepatic steatosis index (HSI) and fatty liver index (FLI) quartiles.

RESULTS

As HSI quartiles increased, the LMM risk increased gradually, after adjusting for age, sex, lifestyle factors, comorbidities, and several causative factors (insulin resistance, inflammation, and vitamin D) (Q4 vs. Q1 OR [95% CI] 3.46 [2.23-5.35]). The increased risk of LMS was even higher according to HSI quartiles (Q4 vs. Q1 5.81 [3.67-9.21]). Multivariate analyses based on FLI showed similar results. People with NAFLD (HSI > 36) were at higher risk of developing LMM and LMS compared to those without (1.65 [1.19-2.31] and 2.29 [1.61-3.26], respectively).

CONCLUSIONS

The presence of NAFLD may predict future risk of LMM and LMS, with greater impact on LMS than on LMM.

Mitochondrial and metabolic dysfunction in ageing and age-related diseases

Organismal ageing is accompanied by progressive loss of cellular function and systemic deterioration of multiple tissues, leading to impaired function and increased vulnerability to death. Mitochondria have become recognized not merely as being energy suppliers but also as having an essential role in the development of diseases associated with ageing, such as neurodegenerative and cardiovascular diseases. A growing body of evidence suggests that ageing and age-related diseases are tightly related to an energy supply and demand imbalance, which might be alleviated by a variety of interventions, including physical activity and calorie restriction, as well as naturally occurring molecules targeting conserved longevity pathways. Here, we review key historical advances and progress from the past few years in our understanding of the role of mitochondria in ageing and age-related metabolic diseases. We also highlight emerging scientific innovations using mitochondria-targeted therapeutic approaches.

Self-nanoemulsifying composition containing curcumin, quercetin, Ganoderma lucidum extract powder and probiotics for effective treatment of type 2 diabetes mellitus in streptozotocin induced rats

Liquid self-nanoemulsifying drug delivery system (L-SNEDDS) of curcumin and quercetin were prepared by dissolving them in isotropic mixture of Labrafil M1944CS®, Capmul MCM®, Tween-80® and Transcutol P®. The prepared L-SNEDDS were solidified using Ganoderma lucidum extract, probiotics and Aerosil-200® using spray drying. These were further converted into pellets using extrusion-spheronization. The mean droplet size and zeta potential of L-SNEDDS were found to be 63.46 ± 2.12 nm and - 14.8 ± 3.11 mV while for solid SNEDDS pellets, these were 72.46 ± 2.16 nm and -38.7 ± 1.34 mV, respectively. The dissolution rate for curcumin and quercetin each was enhanced by 4.5 folds while permeability was enhanced by 5.28 folds (curcumin) and 3.35 folds (quercetin) when loaded into SNEDDS pellets. The Cmax for curcumin and quercetin containing SNEDDS pellets was found 532.34 ± 5.64 ng/mL and 4280 ± 65.67 ng/mL, respectively. This was 17.55 and 3.48 folds higher as compared to their naïve forms. About 50.23- and 5.57-folds increase in bioavailability was observed for curcumin and quercetin respectively, upon loading into SNEDDS pellets. SNEDDS pellets were found stable at accelerated storage conditions. The developed formulation was able to normalize the levels of blood glucose, lipids, antioxidant biomarkers, and tissue architecture of pancreas and liver in streptozotocin induced diabetic rats as compared to their naïve forms.

Serum Metabolomics in Patients with Coexisting NAFLD and T2DM Using Liquid Chromatography-Mass Spectrometry

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) frequently coexist and can act synergistically to drive adverse outcomes of one another. This study aimed to unravel the metabolomic changes in patients with NAFLD and T2DM, to identify potential noninvasive biomarkers, and to provide insights for understanding the link between NAFLD and T2DM.

METHODS

Three hundred participants aged 35 to 70 years who were diagnosed with NAFLD (n = 100), T2DM (n = 100), or a comorbidity of NAFLD and T2DM (n = 100) were included in this study. Anthropometrics and routine blood chemistry were assessed after overnight fast. The global serum metabolomic analysis was performed by ultra-performance liquid chromatography-Orbitrap mass spectrometry. Multivariate data analysis methods were utilized to identify the potential biomarkers.

RESULTS

A set of serum biomarkers that could effectively separate NAFLD from NAFLD + T2DM and T2DM from NAFLD + T2DM were identified. We found that patients with coexisting NAFLD and T2DM had significantly higher levels of total protein (TP), triglycerides (TG), glucose in urine, and gamma-hydroxybutyric acid than those with NAFLD and had significant increased levels of TP, albumin, alanine aminotransferase, aspartate aminotransferase, total cholesterol, cholinesterase, TG, low-density lipoprotein, and apolipoprotein A when compared to patients with T2DM.

CONCLUSION

The metabolomics results provide evidence that the comorbidity of NAFLD and T2DM considerably altered patients' metabolomics patterns compared to those of patients with only NAFLD or T2DM.

Magnetic Resonance Imaging Assessment of Abdominal Ectopic Fat Deposition in Correlation With Cardiometabolic Risk Factors

PURPOSE

Ectopic fat accumulation and abdominal fat distribution may have different cardiometabolic risk profiles. This study aimed to assess the associations between various magnetic resonance imaging (MRI)-acquired fat depots and cardiometabolic risk factors.

METHODS

A total of 320 subjects with median age of 59 years, 148 men and 172 women, were enrolled in the study. Visceral adipose tissue (VAT) area and fat fraction (FF), subcutaneous adipose tissue (SAT) area and FF at the L1-L2 levels, preperitoneal adipose tissue (pPAT) area and FF, hepatic FF, pancreatic FF, and intramuscular FF were assessed by MRI FF maps. The associations of various MRI-acquired fat depots with blood pressure, glucose, and lipid were examined using sex-stratified linear regression. Logistic regression stratified by sex was used to analyze the association of various MRI-acquired fat depots with the risk of hypertension, T2DM, and dyslipidemia.

RESULTS

The intraclass correlation coefficient (ICC) values were >0.9, which suggested good interobserver and intraobserver agreement. VAT area, V/S, hepatic fat, pancreatic fat, and pPAT rather than SAT area were significantly associated with multiple cardiometabolic risk factors (all p < 0.05). However, the patterns of these correlations varied by sex and specific risk factors. Also, VAT and SAT FF were only significantly associated with multiple cardiometabolic risk factors in women (all p < 0.05).

CONCLUSIONS

VAT, hepatic fat, pancreatic fat, and pPAT were associated with cardiovascular metabolic risk factors independent of BMI. The patterns of these correlations were related to gender. These findings further the understanding of the association between ectopic fat deposition and cardiometabolic risk factors and help to better understand the obesity heterogeneity.

Association Between the Risk of Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes and Chronic Kidney Disease

OBJECTIVE

To explore the relationship between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 1168 patients with T2DM were divided into the non-CKD and CKD groups, and the difference in the prevalence of NAFLD was compared. The differences in serum creatinine (SCr) and urine albumin-to-creatinine ratio (UACR) levels were compared between the non-NAFLD and NAFLD groups. Patients with T2DM were divided into three groups according to their UACR levels (UACR < 30 mg/g [U1 group]; UACR ≤ 30 mg/g to < 300 mg/g [U2 group]; and UACR ≥ 300 mg/g [U3 group]) or estimated glomerular filtration rate (eGFR) levels (≥ 90 mL/min [G1 group]; eGFR ≤ 60 mL/min to < 90 mL/min [G2 group]; and eGFR < 60 mL/min (G3 group]). The difference in the prevalence and risks of NAFLD in the different UACR or eGFR level groups was analyzed.

RESULTS

The prevalence of NAFLD in the CKD group was higher than that in the non-CKD group (63.5% vs 50.5%, p < 0.001). The SCr and UACR levels in the NAFLD group were higher than those in the non-NAFLD group (both p<0.05). The prevalence of NAFLD in the U3 group (75.6%) was higher than that in the U1 (50.5%, p < 0.05) and U2 (60.1%, p < 0.05) groups, and the prevalence of NAFLD in the U2 group (60.1%) was higher than that in the U1 group (50.5%, p < 0.05). The risk of NAFLD in the U3 group was higher than that in the U2 group (odds ratio [OR] = 3.032 and 1.473). Despite adjusting the parameters further, the NAFLD risk in the U3 group remained higher than that in the U2 group (OR = 1.660 and 2.342).

CONCLUSION

The risk of NAFLD in patients with T2DM is closely related to CKD.

Metabolic-Associated Fatty Liver Disease (MAFLD), Diabetes, and Cardiovascular Disease: Associations with Fructose Metabolism and Gut Microbiota

Non-alcoholic fatty liver disease (NAFLD) is an increasingly common condition associated with type 2 diabetes (T2DM) and cardiovascular disease (CVD). Since systemic metabolic dysfunction underlies NAFLD, the current nomenclature has been revised, and the term metabolic-associated fatty liver disease (MAFLD) has been proposed. The new definition emphasizes the bidirectional relationships and increases awareness in looking for fatty liver disease among patients with T2DM and CVD or its risk factors, as well as looking for these diseases among patients with NAFLD. The most recommended treatment method of NAFLD is lifestyle changes, including dietary fructose limitation, although other treatment methods of NAFLD have recently emerged and are being studied. Given the focus on the liver-gut axis targeting, bacteria may also be a future aim of NAFLD treatment given the microbiome signatures discriminating healthy individuals from those with NAFLD. In this review article, we will provide an overview of the associations of fructose consumption, gut microbiota, diabetes, and CVD in patients with NAFLD.

Increased Visit-to-Visit Liver Enzyme Variability Is Associated with Incident Diabetes: A Community-Based 12-Year Prospective Cohort Study

BACKGROUND

Fatty liver and/or increased liver enzyme values have been reported to be associated with incident diabetes. We sought to determine whether increased visit-to-visit liver enzyme variability is associated with incident diabetes.

METHODS

Study participants were recruited from the Korean Genome and Epidemiologic Study (KoGES). A total of 4,151 people aged 40 to 69 years was recruited and tested every 2 years for up to 12 years. Visit-to-visit aspartate aminotransferase (AST) and alanine aminotransferase (ALT) variability was evaluated in first the 6-year period through the use of various variability measurements: standard deviation (SD), average successive variability, coefficient of variation (CV), and variation independent of mean (VIM). Oral glucose tolerance test was performed at every visit.

RESULTS

During the 6-year follow-up appointments, 13.0% (538/4,151) of people developed incident diabetes. Visit-to-visit AST variability was associated with an increased risk of diabetes independent of conventional risk factors for diabetes (hazard ratio per 1-SD increment [95% confidence interval]: 1.06 [1.00 to 1.11], 1.12 [1.04 to 1.21], and 1.13 [1.04 to 1.22] for SD, CV, and VIM, respectively; all P<0.05); however, no such associations were observed in the visit-to-visit ALT variability. According to alcohol consumption status, both AST and ALT variability were independent predictors for incident diabetes in subjects with heavy alcohol consumption; however, neither AST nor ALT variability was associated with diabetes risk in subjects who did not drink alcohol heavily.

CONCLUSION

Visit-to-visit liver enzyme variability is an independent predictor of incident diabetes. Such association was more evident in those who consumed significant amounts of alcohol.

Does NAFLD mediate the relationship between obesity and type 2 diabetes risk? evidence from the multi-ethnic study of atherosclerosis (MESA)

PURPOSE

To estimate the effect of obesity on type 2 diabetes (T2DM) risk and evaluate to what extent non-alcoholic fatty liver disease (NAFLD) mediates this association.

METHODS

Data came from 4,522 adults ages 45-84 participating in the Multi-Ethnic Study of Atherosclerosis cohort. Baseline obesity was defined using established BMI categories. NAFLD was measured by CT scans at baseline and incident T2DM defined as fasting glucose ≥126 mg/dL or use of diabetes medications.

RESULTS

Over a median 9.1 years of follow-up between 2000 and 2012, 557 new cases of T2DM occurred. After adjusting for age, sex, race/ethnicity, education, diet and exercise, those with obesity had 4.5 times the risk of T2DM compared to normal weight (hazard ratio [HR] = 4.5, 95% confidence interval [CI]: 3.0, 5.9). The mediation analysis suggested that NAFLD accounted for ~36% (95% CI: 27, 44) of the effect (direct effect HR = 3.2, 95% CI: 2.3, 4.6; indirect effect through NAFLD, HR = 1.4, 95% CI: 1.3, 1.5).

CONCLUSIONS

These data suggest that the association between obesity and T2DM risk is partially explained by the presence of NAFLD. Future studies should evaluate if NAFLD could be an effective target to reduce the effect of obesity on T2DM.

Risk factors, epidemiology and prognosis of cholangiocarcinoma in Finland

Background

Cholangiocarcinoma (CCA) is a cancer arising from the intra‐ and extrahepatic bile ducts. The early stages are often asymptomatic, CCA is frequently diagnosed in an advanced stage and the prognosis of CCA is often dismal.

Objective

Our objective was to estimate the incidence of CCA in Finland and to identify risk factors for CCA, with a special interest in primary sclerosing cholangitis (PSC).

Methods

We identified all CCA cases during 1974–2018 from the Finnish Cancer Registry and calculated age‐standardised incidence rates. Five controls for each case were extracted from the Population Registry, matched by age, gender and municipality of residence at the time of diagnosis. Odds ratios (ORs) for risk factors were estimated with conditional logistic regression and survival estimates with the Kaplan–Meier method.

Results

Incidence of CCA remained stable in both genders; the age‐standardised rate (World Standard) in 2013–2017 in males and females was 1.7 per 100,000 person years and 1.3 per 100,000 person years, respectively. Primary sclerosing cholangitis carried a 30‐fold risk of intrahepatic cholangiocarcinoma (iCCA) and 25‐fold risk of extrahepatic cholangiocarcinoma (eCCA). Diabetes, inflammatory bowel disease and liver cirrhosis were associated with iCCA, whereas cholelithiasis and viral hepatitis C were associated with eCCA. The cumulative 5‐year survival was 4.6%.

Conclusions

The incidence of CCA has been stable. Known risk factors for CCA were confirmed, with PSC having the highest OR. Survival remains poor.

The complex link between NAFLD and type 2 diabetes mellitus - mechanisms and treatments

Nonalcoholic fatty liver disease (NAFLD) has reached epidemic proportions worldwide. NAFLD and type 2 diabetes mellitus (T2DM) are known to frequently coexist and act synergistically to increase the risk of adverse (hepatic and extra-hepatic) clinical outcomes. T2DM is also one of the strongest risk factors for the faster progression of NAFLD to nonalcoholic steatohepatitis, advanced fibrosis or cirrhosis. However, the link between NAFLD and T2DM is more complex than previously believed. Strong evidence indicates that NAFLD is associated with an approximate twofold higher risk of developing T2DM, irrespective of obesity and other common metabolic risk factors. This risk parallels the severity of NAFLD, such that patients with more advanced stages of liver fibrosis are at increased risk of incident T2DM. In addition, the improvement or resolution of NAFLD (on ultrasonography) is associated with a reduction of T2DM risk, adding weight to causality and suggesting that liver-focused treatments might reduce the risk of developing T2DM. This Review describes the evidence of an association and causal link between NAFLD and T2DM, discusses the putative pathophysiological mechanisms linking NAFLD to T2DM and summarizes the current pharmacological treatments for NAFLD or T2DM that might benefit or adversely affect the risk of T2DM or NAFLD progression.

Nonalcoholic fatty liver disease and the risk of insulin-requiring gestational diabetes

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases; however, there has been little research into its impact on gestational diabetes mellitus (GDM).

METHODS

This study included 308,095 women registered in the Korean National Health Insurance Service database, who delivered between 2011 and 2015 and received a health examination within 52 weeks before pregnancy. Insulin-requiring GDM was defined as no insurance claims for diabetes mellitus and a fasting blood glucose level of < 126 mg/dL before pregnancy, and initiation of insulin treatment during pregnancy. A fatty liver index (FLI) was calculated using body mass index, waist circumference, and blood triglyceride and γ-glutamyl transferase levels. FLI scores < 30 ruled out hepatic steatosis, while FLI scores ≥ 60 indicated NAFLD.

RESULTS

The prevalence of NAFLD was 0.8% (2355/308,095) and 1984 (0.6%) subjects developed insulin-requiring GDM. FLIs of 30-59 and ≥ 60 were significantly associated with increased risk of insulin-requiring GDM (odds ratio [OR] 3.50; 95% confidence interval [CI] 2.99-4.10; OR 4.19; 95% CI 3.37-5.23), respectively. Further exploration of the association of FLI with GDM across FLI decile categories revealed a steady increase in OR across the categories. The association was more prominent among those without metabolic syndrome.

CONCLUSION

NAFLD in women is an independent risk factor for insulin-requiring GDM.

Elevated Fatty Liver Index Is Independently Associated With New Onset of Hypertension During a 10-Year Period in Both Male and Female Subjects

Background

Fatty liver index (FLI), a predictor of nonalcoholic fatty liver disease, has been reported to be associated with several metabolic disorders. Because of a sex difference in FLI level, we hypothesized that FLI is associated with development of hypertension to a greater extent in men or women.

Methods and Results

We investigated the relationship between FLI and development of hypertension during a 10‐year period in a general population of subjects who received annual health examinations (n=28 990). After exclusion (44.9%) of subjects with missing data and those with hypertension at baseline, a total of 15 965 subjects (men/women: 9466/6499) were included. FLI level was significantly higher in men than in women. During the 10‐year period, 2304 men (24.3%) and 745 women (11.5%) had new onset of hypertension. Multivariable Cox proportional hazard models with a restricted cubic spline showed that the hazard ratios (HRs) for development of hypertension after adjustment of age, systolic blood pressure, estimated glomerular filtration rate, habits of smoking and alcohol drinking, family history of hypertension, and diagnosis of diabetes mellitus and dyslipidemia increased gradually with increase in FLI in men and increased rapidly and then slowly with increase in FLI in women. There was a significant interaction between FLI and sex for the risk of hypertension in all of the subjects (P=0.049). The addition of FLI to traditional risk factors significantly improved the discriminatory capability.

Conclusions

A high level of FLI predicts the development of hypertension in both men and women, although distribution patterns of HRs were different between sexes.

Is HSD17B13 Genetic Variant a Protector for Liver Dysfunction? Future Perspective as a Potential Therapeutic Target

As diet and lifestyle have changed, fatty liver disease (FLD) has become more and more prevalent. Many genetic risk factors, such as variants of PNPLA3, TM6SF2, GCKR, and MBOAT7, have previously been uncovered via genome wide association studies (GWAS) to be associated with FLD. In 2018, a genetic variant (rs72613567, T > TA) of hydroxysteroid 17-β dehydrogenase family 13 (HSD17B13) was first associated with a lower risk of developing alcoholic liver disease and non-alcoholic fatty liver disease (NAFLD) in minor allele carriers. Other HSD17B13 variants were also later linked with either lower inflammation scores among NAFLD patients or protection against NAFLD (rs6834314, A > G and rs9992651, G > A) respectively. HSD17B13 is a lipid droplet-associated protein, but its function is still ambiguous. Compared to the other genetic variants that increase risk for FLD, HSD17B13 variants serve a protective role, making this gene a potential therapeutic target. However, the mechanism by which these variants reduce the risk of developing FLD is still unclear. Because studies in cell lines and mouse models have produced conflicting results, human liver tissue modeling using induced pluripotent stem cells may be the best way to move forward and solve this mystery.

Association of hepatic steatosis derived from ultrasound and quantitative MRI with prediabetes in the general population

The aim of our study was to investigate the association of hepatic steatosis derived from quantitative ultrasound and magnetic resonance imaging (MRI) with prediabetes in a large population-based study conducted in Northeast Germany. Hepatic steatosis was assessed through transabdominal ultrasound and quantitative MRI. For analysis we included 1622 subjects with MRI who participated in an oral glucose tolerance test and reported no known type 2 diabetes mellitus (T2DM). We classified participants as proposed by the American Diabetes Association: isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), combined IFG and IGT (IFG + IGT), and undiagnosed T2DM. Regression models were adjusted for age, sex body mass index and alcohol consumption. We observed positive associations of hepatic steatosis with glycated hemoglobin, fasting glucose and insulin, 2-h glucose and insulin, as well as homeostasis model assessment-insulin resistance index. Similarly, individuals having hepatic steatosis as defined by MRI had a higher relative risk ratio (RR) to be in the prediabetes groups i-IFG (RR = 1.6; 95% confidence interval (CI) 1.2; 2.2), i-IGT (RR = 3.3, 95% CI 2.0; 5.6) and IFG + IGT (RR = 2.5, 95% CI 1.6; 3.9) or to have undiagnosed T2DM (RR = 4.8, 95% CI 2.6; 9.0). All associations were attenuated when defining hepatic steatosis by ultrasound. Hepatic steatosis is associated with prediabetes and undiagnosed T2DM in the general population. Quantitative liver MRI revealed stronger associations with prediabetes and undiagnosed T2DM compared to ultrasound, which indicates the higher sensitivity and specificity of MRI to determine hepatic steatosis.

Polycystic ovary syndrome with feasible equivalence to overweight as a risk factor for non-alcoholic fatty liver disease development and severity in Mexican population

INTRODUCTION AND OBJECTIVES

Polycystic ovary syndrome (PCOS) is the most common endocrinology disorder in women of reproductive age; these patients have a higher risk of suffering from non-alcoholic fatty liver disease (NAFLD). We determine the frequency of NAFLD in Mexican patients with PCOS and matched-controls.

PATIENTS AND METHODS

Cross-sectional study, with 98 women of 18-44 years old. Rotterdam 2003 criteria integrated PCOS diagnosis. Those with significant alcohol consumption, chronic liver disease, use of steatogenic drugs, and pharmacological PCOS treatment or fertility protocol were excluded. Controls were matched in a 1:1 ratio by age and body mass index (BMI). The presence of NAFLD was determined by transient elastography performed by a single experienced operator.

RESULTS

A total of 98 female volunteers at reproductive age were recruited. NAFLD denoted markedly higher in patients with than without PCOS at 69.3% vs. 34.6%, respectively. Compared to controls, PCOS patients had a significantly higher risk of NAFLD (OR=4.26, 95% CI 1.83-9.93). Severe steatosis was the most frequent NAFLD stage between women with PCOS and NAFLD. Patients with hyperandrogenism have a significantly higher mean CAP 277.83dB/m than controls without hyperandrogenism 191.57dB/m. NAFLD prevalence was 84.3% in PCOS patients with phenotype A, while in another phenotype, it was 41.1%.

CONCLUSIONS

PCOS is an independent risk factor for NAFLD development. NAFLD screening needs to be considered in all PCOS patients independently of BMI, except in PCOS patients without hyperandrogenism and BMI<25.

High level of fatty liver index predicts new onset of diabetes mellitus during a 10-year period in healthy subjects

Fatty liver index (FLI), a predictor of nonalcoholic fatty liver disease, has been reported to be associated with several metabolic disorders. This study aimed to evaluate the relationship between FLI and new onset of diabetes mellitus (DM). We investigated the association of FLI with new onset of DM during a 10-year period in subjects who received annual health examinations (n = 28,990). After exclusion of subjects with DM at baseline and those with missing data, a total of 12,290 subjects (male/female: 7925/4365) who received health examinations were recruited. FLI was significantly higher in males than in females. During the 10-year period, DM was developed in 533 males (6.7%) and 128 females (2.9%). Multivariable Cox proportional hazard models with a restricted cubic spline showed that the risk of new onset of DM increased with a higher FLI at baseline in both sexes after adjustment of age, fasting plasma glucose, habits of alcohol drinking and current smoking, family history of DM and diagnosis of hypertension and dyslipidemia at baseline. When the subjects were divided into subgroups according to tertiles of FLI level at baseline (T1–T3) in the absence and presence of impaired fasting glucose (IFG), hazard ratios after adjustment of the confounders gradually increased from T1 to T3 and from the absence to presence of IFG in both male and female subjects. In conclusion, a high level of FLI predicts new onset of DM in a general population of both male and female individuals.

Histological severity of nonalcoholic fatty liver disease is associated with 10-year risk for atherosclerotic cardiovascular disease

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) is associated with atherosclerotic cardiovascular disease (ASCVD). However, few studies have investigated the association between the histological severity of NAFLD and ASCVD. Therefore, we investigated whether the histological severity of NAFLD is associated with ASCVD risk.

METHODS

We performed cross-sectional analysis of prospectively enrolled, biopsy-proven NAFLD patients. The 10-year ASCVD risk was assessed using the Korean Risk Prediction Model. The histological spectrum of NAFLD was classified by the nonalcoholic steatohepatitis (NASH) clinical research network histological scoring system. The association between each histological subgroup and ASCVD risk was analyzed using logistic regression analysis.

RESULTS

This study included 398 Korean subjects (mean age, 57.9 years; male, 44.2%) with biopsy-proven NAFLD and 102 no-NALFD controls. Subjects with ASCVD risk ≥ 10% showed more severe grades of hepatocellular ballooning and more advanced stages of fibrosis when compared with subjects with ASCVD risk < 10% (p < 0.05 for each). The presence of NASH (odds ratio [OR] 4.07; 95% confidence interval [CI] 1.40-11.88) or advanced fibrosis (OR 8.11; 95% CI 1.83-35.98) was independently associated with a higher risk of ASCVD even after adjustment for age, sex, body mass index, blood pressure, lipids, liver enzymes, systemic inflammation, and insulin resistance.

CONCLUSIONS

Patients with NASH or advanced fibrosis are at an increased risk of developing ASCVD compared with no-NAFLD controls or subjects with NAFL, independent of conventional metabolic risk factors for CVD. Histological information on NAFLD may be helpful to promote our understanding of extrahepatic complications, such as ASCVD, resulting from NAFLD progression.

Burden of increased blood glucose due to modifiable risk factors among men in India

BACKGROUND AND AIMS

Worldwide, many diabetes cases are occurring mainly due to lifestyle risk factors. Hence, to quantify and compare the attributable burden of key modifiable risk factors associated with increased Blood Glucose (BG) among Indian states and districts.

METHODS

The study used the National Family Health Survey (2015-16) data to estimate Population Attributable Risk (PAR) for increased BG (>140 mg/dl) among men aged 15-54 years in 640 districts of 36 States/Union Territories (UTs), India. We have considered three key modifiable factors such as high Body Mass Index (BMI), use of tobacco and alcohol. Population Attributable Risk techniques were employed to address the attributable burden of increased blood glucose due to modifiable risk factors.

RESULTS

Substantial variations were found in the burden of increased BG due to high BMI, alcohol and tobacco use in India. The overall burden of increased BG due to high BMI, tobacco and alcohol in India was 28.5%, 2.1% and 6.4%, respectively. Regional variations in BG were found in high BMI, tobacco and alcohol consumption groups. The high burden of increased BG related to the above key modifiable risk factors mostly seen in North-Eastern' districts due to alcohol, Southern and Northern' districts was due to high BMI. However, the higher burden due to tobacco was reported in Central, Eastern and North-Eastern' districts.

CONCLUSION

Three modifiable risk factors are contributing significantly to increased BG among men. Since there are regional differences in their contributions, state/district, specific targeted interventions may be necessary to control increased BG among men in India.

Genetic predisposition similarities between NASH and ASH: Identification of new therapeutic targets

Fatty liver disease can be triggered by a combination of excess alcohol, dysmetabolism and other environmental cues, which can lead to steatohepatitis and can evolve to acute/chronic liver failure and hepatocellular carcinoma, especially in the presence of shared inherited determinants. The recent identification of the genetic causes of steatohepatitis is revealing new avenues for more effective risk stratification. Discovery of the mechanisms underpinning the detrimental effect of causal mutations has led to some breakthroughs in the comprehension of the pathophysiology of steatohepatitis. Thanks to this approach, hepatocellular fat accumulation, altered lipid droplet remodelling and lipotoxicity have now taken centre stage, while the role of adiposity and gut-liver axis alterations have been independently validated. This process could ignite a virtuous research cycle that, starting from human genomics, through omics approaches, molecular genetics and disease models, may lead to the development of new therapeutics targeted to patients at higher risk. Herein, we also review how this knowledge has been applied to: a) the study of the main PNPLA3 I148M risk variant, up to the stage of the first in-human therapeutic trials; b) highlight a role of MBOAT7 downregulation and lysophosphatidyl-inositol in steatohepatitis; c) identify IL-32 as a candidate mediator linking lipotoxicity to inflammation and liver disease. Although this precision medicine drug discovery pipeline is mainly being applied to non-alcoholic steatohepatitis, there is hope that successful products could be repurposed to treat alcohol-related liver disease as well.

Hepatokines and adipokines in NASH-related hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is increasing in industrialised societies; this is likely secondary to the increasing burden of non-alcoholic fatty liver disease (NAFLD), its progressive form non-alcoholic steatohepatitis (NASH), and the metabolic syndrome. Cumulative studies suggest that NAFLD-related HCC may also develop in non-cirrhotic livers. However, prognosis and survival do not differ between NAFLD- or virus-associated HCC. Thus, research has increasingly focused on NAFLD-related risk factors to better understand the biology of hepatocarcinogenesis and to develop new diagnostic, preventive, and therapeutic strategies. One important aspect thereof is the role of hepatokines and adipokines in NAFLD/NASH-related HCC. In this review, we compile current data supporting the use of hepatokines and adipokines as potential markers of disease progression in NAFLD or as early markers of NAFLD-related HCC. While much work must be done to elucidate the mechanisms and interactions underlying alterations to hepatokines and adipokines, current data support the possible utility of these factors - in particular, angiopoietin-like proteins, fibroblast growth factors, and apelin - for detection or even as therapeutic targets in NAFLD-related HCC.

PCSK9 rs11591147 R46L loss-of-function variant protects against liver damage in individuals with NAFLD

BACKGROUND AND AIMS

The proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis, and its inhibition represents an effective therapy to lower low-density lipoprotein cholesterol (LDL-C) levels. In this study, we examined the impact of the PCSK9 rs11591147 loss-of-function (LOF) variant on liver damage in a multicenter collection of patients at risk of nonalcoholic steatohepatitis (NASH), in clinical samples and experimental models.

METHODS

We considered 1874 consecutive individuals at risk of NASH as determined by histology. The SNP rs11591147, encoding for the p.R46L variant of PCSK9, was genotyped by TaqMan assays. We also evaluated 1) PCSK9 mRNA hepatic expression in human liver, and 2) the impact of a NASH-inducing diet in mice with hepatic overexpression of human PCSK9.

RESULTS

Carriers of PCSK9 rs11591147 had lower circulating LDL-C levels and were protected against nonalcoholic fatty liver disease (NAFLD) (OR: 0.42; 95% CI: 0.22-0.81; P = .01), NASH (OR: 0.48; 95% CI: 0.26-0.87; P = .01) and more severe fibrosis (OR: 0.55; 95% CI: 0.32-0.94; P = .03) independently of clinical, metabolic and genetic confounding factors. PCSK9 hepatic expression was directly correlated with liver steatosis (P = .03). Finally, liver-specific overexpression of human PCSK9 in male mice drives NAFLD and fibrosis upon a dietary challenge.

CONCLUSIONS

In individuals at risk of NASH, PCSK9 was induced with hepatic fat accumulation and PCSK9 rs11591147 LOF variant was protective against liver steatosis, NASH and fibrosis, suggesting that PCSK9 inhibition may be a new therapeutic strategy to treat NASH.

A human pluripotent stem cell model for the analysis of metabolic dysfunction in hepatic steatosis

Nonalcoholic fatty liver disease (NAFLD) is currently the most prevalent form of liver disease worldwide. This term encompasses a spectrum of pathologies, from benign hepatic steatosis to non-alcoholic steatohepatitis, which have, to date, been challenging to model in the laboratory setting. Here, we present a human pluripotent stem cell (hPSC)-derived model of hepatic steatosis, which overcomes inherent challenges of current models and provides insights into the metabolic rewiring associated with steatosis. Following induction of macrovesicular steatosis in hepatocyte-like cells using lactate, pyruvate, and octanoate (LPO), respirometry and transcriptomic analyses revealed compromised electron transport chain activity. 13C isotopic tracing studies revealed enhanced TCA cycle anaplerosis, with concomitant development of a compensatory purine nucleotide cycle shunt leading to excess generation of fumarate. This model of hepatic steatosis is reproducible, scalable, and overcomes the challenges of studying mitochondrial metabolism in currently available models.

Combined associations of liver enzymes and obesity with diabetes mellitus prevalence: The Tohoku Medical Megabank Community-based Cohort Study

BACKGROUND

Alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) are enzymes associated with diabetes mellitus (DM) prevalence. However, limited information is available regarding the association of liver enzymes and DM consistently present in obese and non-obese individuals. We examined whether the combination of ALT and GGT enzymes is associated with the prevalence of DM regardless of obesity in a general Japanese population.

METHODS

We conducted a cross-sectional study of 62,786 participants aged ≥20 years who lived in Miyagi and Iwate, Japan. We divided all the participants into eight groups according to the ALT level (low: <30 IU/L and high: ≥30 IU/L), GGT level (low: <50 IU/L and high: ≥50 IU/L), and the presence of obesity. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression analysis, adjusting for potential confounders, to determine associations of the combination of ALT and GGT levels and obesity with DM prevalence.

RESULTS

Overall, 6,008 participants (9.6%) had DM. Compared to non-obese individuals with low ALT and GGT levels, the participants with high ALT and GGT levels had high ORs for DM in both obese (OR 4.06; 95% CI, 3.61-4.56) and non-obese groups (OR 2.19; 95% CI, 1.89-2.52). The obese group had high ORs for DM, even at low ALT and GGT levels.

CONCLUSION

High ALT and GGT levels are associated with DM prevalence in obese and non-obese participants. This finding suggests that correcting ALT and GGT levels and controlling obesity are important for the prevention of DM.

Nonalcoholic Fatty Liver Disease and Estimated Insulin Resistance in Obese Youth: A Mendelian Randomization Analysis

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is associated with insulin resistance (IR) and predicts type 2 diabetes. Currently, it is uncertain whether NAFLD may directly cause IR or vice versa.

OBJECTIVE

To test the hypothesis that NAFLD is causally related to IR.

DESIGN AND METHODS

We performed a Mendelian randomization (MR) in 904 obese children/adolescents using an NAFLD-related genetic risk score (GRS) as an instrumental variable. We assessed NAFLD by ultrasonography and IR by homeostasis model assessment (HOMA-IR). We also interrogated the MAGIC Consortium dataset of 46 186 adults to assess the association between PNPLA3 rs738409 (ie, the most robust NAFLD-related polymorphism) and HOMA-IR, and we performed a 2-sample MR with 2 large datasets to test reverse causation (HOMA-IR increasing the risk of NAFLD).

RESULTS

Nonalcoholic fatty liver disease prevalence increased by 20% for every increase in the GRS (β-coefficient = 0.20, P < 0.001), and NAFLD was associated with ln-HOMA-IR (β-coefficient = 0.28, P < 0.001). Thus, the expected increase in ln-HOMA-IR for every increase in the GRS (expected β-coefficient) was 0.056 (0.28*0.20) in the case of complete NAFLD-HOMA-IR causal association, and 0.042 in the case of 75% causality. In our cohort, the GRS did not predict ln-HOMA-IR (β-coefficient = 0.007, P = 0.75). In the MAGIC cohort, the PNPLA3 rs738409 did not associate with ln-HOMA-IR. The 2-sample MR failed to show a causal association between ln-HOMA-IR and NAFLD.

CONCLUSIONS

Our study shows that genetically-influenced NAFLD does not increase HOMA-IR, and genetically-influenced HOMA-IR does not increase the risk of NAFLD. Shared pathogenic pathways or NAFLD subtypes not "captured" by our MR design might underpin the association between NAFLD and HOMA-IR.

DNA Methylation in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a widespread hepatic disorder in the United States and other Westernized countries. Nonalcoholic steatohepatitis (NASH), an advanced stage of NAFLD, can progress to end-stage liver disease, including cirrhosis and liver cancer. Poor understanding of mechanisms underlying NAFLD progression from simple steatosis to NASH has limited the development of effective therapies and biomarkers. An accumulating body of studies has suggested the importance of DNA methylation, which plays pivotal roles in NAFLD pathogenesis. DNA methylation signatures that can affect gene expression are influenced by environmental and lifestyle experiences such as diet, obesity, and physical activity and are reversible. Hence, DNA methylation signatures and modifiers in NAFLD may provide the basis for developing biomarkers indicating the onset and progression of NAFLD and therapeutics for NAFLD. Herein, we review an update on the recent findings in DNA methylation signatures and their roles in the pathogenesis of NAFLD and broaden people’s perspectives on potential DNA methylation-related treatments and biomarkers for NAFLD.

Human and molecular genetics shed lights on fatty liver disease and diabetes conundrum

The causal role of abdominal overweight/obesity, insulin resistance and type 2 diabetes (T2D) on the risk of fatty liver disease (FLD) has robustly been proven. A consensus of experts has recently proposed the novel definition of 'metabolic dysfunction-associated fatty liver disease, MAFLD' instead of 'nonalcoholic fatty liver disease, NAFLD', emphasizing the central role of dysmetabolism in the disease pathogenesis. Conversely, a direct and independent contribution of FLD per se on risk of developing T2D is still a controversial topic. When dealing with FLD as a potential risk factor for T2D, it is straightforward to think of hepatic insulin resistance as the most relevant underlying mechanism. Emerging evidence supports genetic determinants of FLD (eg PNPLA3, TM6SF2, MBOAT7, GCKR, HSD17B13) as determinants of insulin resistance and T2D. However, recent studies highlighted that the key molecular mechanism of dysmetabolism is not fat accumulation per se but the degree of hepatic fibrosis (excess liver fat content-lipotoxicity), leading to reduced insulin clearance, insulin resistance and T2D. A consequence of these findings is that drugs that will ameliorate liver fat accumulation and fibrosis in principle may also exert a beneficial effect on insulin resistance and risk of T2D in individuals with FLD. Finally, initial findings show that these genetic factors might be directly implicated in modulating pancreatic beta-cell function, although future studies are needed to fully understand this relationship.