Nonalcoholic steatohepatitis: association of insulin resistance and mitochondrial abnormalities

Effects of the triglyceride-glucose index on non-alcoholic fatty liver disease: Causal evidence from longitudinal cohort studies

BACKGROUND

Insulin resistance (IR) is strongly related to non-alcoholic fatty liver disease (NAFLD). Triglyceride-glucose (TyG) index serves as a novel substitute indicator for IR. However, research on the effect of TyG index on NAFLD remains sparse. This study aims to investigate the causal association between TyG index and incident NAFLD.

METHODS

The primary cohort consisted of 27,052 participants from the Beijing Health Management Cohort, while the external validation cohort included 75,023 participants from the Taiwan MJ Cohort. Entropy balancing for continuous treatments (EBCT) combined with logistic regression and targeted maximum likelihood estimation (TMLE) were used to evaluate the causal association between the TyG index and incident NAFLD.

RESULTS

During a median follow-up of 2.49 years in the primary cohort, 6,168 participants (median age: 36.0 years) developed incident NAFLD. EBCT combined with logistic regression revealed the odds ratio (95 % CI) of NAFLD risk was 1.742 (1.478-2.054) for each 1-unit increase in the baseline TyG index. In the TMLE model, the risk ratio (95 % CI) for NAFLD was 1.540 (1.406-1.687) in the Q4 (quartile 4) group compared with the Q1 group. These findings were consistent with those from the external validation cohort, reinforcing the robustness of the causal relationship between the TyG index and NAFLD incidence.

CONCLUSIONS

The advanced double-robust estimation method suggests that a higher baseline TyG index may be causally associated with an increased NAFLD risk, providing more reliable evidence for its role as a simple biomarker and demonstrating the utility of double-robust estimation causal inference models in epidemiology.

The association between different insulin resistance surrogates and all-cause mortality and cardiovascular mortality in patients with metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely associated with insulin resistance (IR). However, the prognostic value of different alternative IR surrogates in patients with MASLD remains unclear. This study aimed to evaluate the association between various IR indices and all-cause mortality and cardiovascular mortality in MASLD patients.

METHODS

A total of 8,753 adults aged ≥ 20 years with MASLD from the National Health and Nutrition Examination Survey (NHANES, 2003-2018) were included, and their mortality data were obtained from the National Death Index (NDI). Insulin resistance surrogates [including the triglyceride-glucose (TyG) index, TyG-body mass index (TyG-BMI), TyG-waist circumference index, TyG-waist-to-height ratio index, and Homeostatic Model Assessment for IR] were stratified into quartiles. Cox proportional hazards models, receiver operating characteristic (ROC) curve analysis, restricted cubic spline (RCS), mediation analyses, and subgroup analyses were used to explore the associations between these indices and all-cause mortality as well as cardiovascular mortality in MASLD patients.

RESULTS

During a median follow-up of 98 months, 1,234 deaths were observed, including 409 cardiovascular disease (CVD)-related deaths. In the fully adjusted model, higher quartiles of TyG-related indices were significantly associated with an increased risk of all-cause mortality in MASLD patients. Furthermore, the TyG-BMI index was associated with both all-cause mortality and CVD mortality [all-cause mortality: HR (95% CI) 2.84 (1.73-4.67), P < 0.001; CVD mortality: HR (95% CI) 5.32 (2.26-12.49), P < 0.001]. The RCS analyses indicated a U-shaped relationship between TyG-BMI and mortality, with a threshold value of 270.49. Subgroup analyses demonstrated that TyG-related indices had stronger associations with mortality in elderly MASLD patients.

CONCLUSIONS

Our findings highlight the prognostic value of IR indices, particularly TyG-BMI index, in predicting all-cause mortality and CVD mortality in MASLD patients.

Aging and metabolic dysfunction-associated steatotic liver disease: a bidirectional relationship

In recent years, aging and cellular senescence have triggered an increased interest in corresponding research fields. Evidence shows that the complex aging process is involved in the development of many chronic liver diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). In fact, aging has a tremendous effect on the liver, leading to a gradual decline in the metabolism, detoxification and immune functions of the liver, which in turn increases the risk of liver disease. These changes can be based on the aging of liver cells (hepatocytes, liver sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells). Similarly, patients with liver diseases exhibit increases in the aging phenotype and aging cells, often manifesting as faster physical functional decline, which is closely related to the promoting effect of liver disease on aging. This review summarizes the interplay between MASLD/MASH development and aging, aiming to reveal the complex relationships that exacerbate one another. Moreover, the corresponding schemes for delaying aging or treating diseases are discussed to provide a basis for the development of effective prevention and treatment strategies in the future.

Weight loss in MASLD restores the balance of liver fatty acid sources

BACKGROUNDLipogenesis contributes substantially to the pathological accumulation of intrahepatic triacylglycerol (IHTG) in metabolic dysfunction-associated steatotic liver disease (MASLD). Since hepatic lipogenesis is highly sensitive to energy intake, we hypothesized that mechanisms of MASLD regression induced by weight loss would be driven by a marked reduction in the lipogenic pathway.METHODSOverweight adults with high liver fat (HighLF; n = 9; IHTG ≥ 5.6% measured by 1H-magnetic resonance spectroscopy) or low (normal) liver fat (LowLF; n = 6; IHTG < 5.6%) received dietary counseling for 6 months and underwent comprehensive metabolic phenotyping during inpatient studies that captured fasting and fed states. Multiple stable isotopes were used to assess the contribution of lipogenesis, free fatty acids (FFAs), and dietary fat to IHTG.RESULTSBody weight loss (-10% ± 2%) reduced IHTG in individuals with MASLD (19.4% ± 3.6% to 4.5% ± 2.1%, P < 0.001). Insulin sensitivity improved significantly (46%, P < 0.01), while fasting FFA flux from adipose tissue was not different. VLDL-triacylglycerol (VLDL-TG) concentrations fell by 38% (P = 0.02) because of a 67% reduction in contribution from lipogenesis (P = 0.02), whereas the absolute contributions from FFAs and dietary fat to VLDL-TG were not different. Reduced lipogenesis was significantly associated with loss of IHTG.CONCLUSIONThese data underscore the primary role of lipogenesis in MASLD pathology and highlight the importance of controlling this pathway through treatment strategies.TRIAL REGISTRATIONClinicalTrials.gov (NCT01371396).FUNDINGNational Institutes of Health (NIH) grant RL1DK081187; Task Force for Obesity Research at Southwestern (TORS) NIH UL1DE019584; and Clinical and Translational Science Award NIH/National Center for Advancing Translational Sciences UL1-RR024982.

Improvement of Glucose Metabolism by Pennogenin 3-O-β-Chacotrioside via Activation of IRS/PI3K/Akt Signaling and Mitochondrial Respiration in Insulin-Resistant Hepatocytes

SCOPE

Insulin resistance (IR), which causes chronic hyperglycemia, has been one of the most prevalent components of metabolic syndrome over the centuries. Pennogenin 3-O-β-chacotrioside (P3C), the main steroid glycoside derived from Paris polyphylla, has been found to exert various biological activities. However, the exact role of P3C on glucose metabolism in the IR state remains unexplored.

METHODS AND RESULTS

To induce IR, AML12 cells were exposed to glucose (27 mM) and insulin (10 µg/mL) and then incubated with P3C (0.25 or 0.5 µM) for 24 h. The effects of P3C on glucose metabolism in insulin-resistant AML12 cells were evaluated through glucose consumption assays, real-time quantitative polymerase chain reaction (qPCR), Western blotting, and metabolic analysis for extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Our data showed that P3C significantly improved insulin sensitivity in AML12 hepatocytes with high glucose-induced IR. P3C stimulated insulin sensitivity and glucose uptake by activating the IRS/PI3K/Akt signaling pathway, which enhances glycogen synthesis and suppresses gluconeogenesis in insulin-resistant AML12 cells. In addition, P3C treatment increased the protein expression of p-AMPK and PGC1α, as well as the expression of oxidative phosphorylation complex proteins, potentially enhancing mitochondrial oxidative respiration.

CONCLUSIONS

Our findings imply that P3C could be a therapeutic option for improving metabolic abnormalities associated with IR.

Female reproductive factors and metabolic dysfunction-associated steatotic liver disease: an integrated analysis of population cohort, liver imaging, and genetic data

BACKGROUND

Although premenopausal women are at lower risk for metabolic dysfunction-associated steatotic liver disease than men within the same age group, the sex advantage becomes minimal after menopause, suggesting a role for female hormones.

OBJECTIVE

This study aimed to elucidate the role of reproductive factors in the development of female metabolic dysfunction-associated steatotic liver disease, using an integrated analysis.

STUDY DESIGN

Up to 269,607 women without metabolic dysfunction-associated steatotic liver disease during baseline recruitment (2006-2010) of the UK Biobank were included. Among these, 21,017 women did not develop metabolic dysfunction-associated steatotic liver disease across the follow-up period (through December 2021) and had the measure of liver proton density fat fraction quantified by magnetic resonance imaging since 2014. Multivariable Cox regression models were applied to assess the prospective relationships of various reproductive factors with incident metabolic dysfunction-associated steatotic liver disease. Multiple linear regression models were used to explore the relationships of reproductive factors with liver proton density fat fraction. A 2-sample Mendelian randomization analysis was conducted to investigate causality in the relationships of certain reproductive factors with metabolic dysfunction-associated steatotic liver disease.

RESULTS

During a median of 12.65 years of follow-up, 3077 incident cases of metabolic dysfunction-associated steatotic liver disease were identified. Early menarche, a greater number of live births, younger age at first live birth, and oral contraceptives or hormone replacement therapy initiated at a young age were associated with an elevated risk of metabolic dysfunction-associated steatotic liver disease and higher levels of liver proton density fat fraction. Several other reproductive factors (ie, a greater number of miscarriages, surgical menopause at a young age, and prolonged use of hormone replacement therapy) were associated with incident metabolic dysfunction-associated steatotic liver disease but not with liver proton density fat fraction. In the Mendelian randomization analysis, genetically determined earlier age at menarche and younger age at first live birth were substantially associated with increased risk of metabolic dysfunction-associated steatotic liver disease.

CONCLUSION

Several reproductive factors were associated with the risk of and histologic features of metabolic dysfunction-associated steatotic liver disease, supporting the role of female hormones in the pathogenesis of metabolic dysfunction-associated steatotic liver disease.

Function of PNPLA3 I148M-Lessons From In Vivo Studies in Humans

BACKGROUND AND AIMS

Steatotic liver disease (SLD) associated with insulin resistance (IR) and the metabolic syndrome ('IR-SLD') increases the risk of liver disease, type 2 diabetes and cardiovascular disease (CVD). SLD associated with the PNPLA3 I148M variant ('PNPLA3-SLD') also predisposes individuals to liver disease but protects against type 2 diabetes and CVD. Although in real life the two causes of SLD commonly co-exist, the opposite effects of 'IR-SLD' and 'PNPLA3-SLD' on CVD and liver disease suggest their pathogenesis differs.

METHODS AND RESULTS

This review summarises human data comparing the effects of 'IR-SLD' and 'PNPLA3-SLD' on the human liver lipidome, hepatic handling of fatty acids, pathways of intrahepatocellular triglyceride synthesis, circulating lipids and lipoproteins and adipose tissue inflammation. We also discuss how steatosis in PNPLA3 I148M carriers leads to defects in mitochondrial function.

Low-Carbohydrate (Ketogenic) Diet in Children with Obesity: Part 1-Diet Impact on Anthropometric Indicators and Indicators of Metabolic Syndrome and Insulin Resistance

BACKGROUND

The ketogenic diet has been successfully used in the last 100 years in the treatment of epilepsy and other neurological disorders. In recent decades, it gained wider application in the treatment of obesity, metabolic syndrome, and type 2 diabetes. However, there have been only a few studies on its use in children with obesity and associated metabolic disorders.

OBJECTIVES

To determine the clinical and metabolic effects of a well-formulated low-carbohydrate (ketogenic) diet in children with obesity.

METHODS

One hundred children with obesity and metabolic disorders underwent initial anthropometric, laboratory, and ultrasound examinations. They were placed on a well-formulated ketogenic diet and monitored for 4 months. The 58 patients who completed the study underwent follow-up examinations to assess the effects of the diet on anthropometric, clinical, and laboratory markers of metabolic syndrome and insulin resistance, cardiovascular risk factors, and certain hormone levels. Compliance with the diet, common difficulties in adhering to it, side effects, and positive changes in the patients' health were analyzed.

RESULTS

At the end of the study, the average weight loss for the entire group was 6.45 kg, with a reduction in BMI of 3.12 kg/m2. Significant improvements were also observed in insulin resistance indicators, including fasting insulin levels, HOMA-IR index, QUICKI (p < 0.0001), and adiponectin (p = 0.04). The cases of hepatosteatosis decreased twofold, the number of patients with arterial hypertension was significantly reduced, as well as the number of children receiving antihypertensive therapy. Additionally, the number of patients meeting the criteria for metabolic syndrome decreased threefold.

CONCLUSIONS

A well-formulated short-term ketogenic diet is effective in treating obesity, metabolic syndrome, and related comorbidities, and can be part of a comprehensive approach for these patients.

Mitochondrial targeted therapies in MAFLD

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a clinical-pathological syndrome primarily characterized by excessive accumulation of fat in hepatocytes, independent of alcohol consumption and other well-established hepatotoxic agents. Mitochondrial dysfunction is widely acknowledged as a pivotal factor in the pathogenesis of various diseases, including cardiovascular diseases, cancer, neurodegenerative disorders, and metabolic diseases such as obesity and obesity-associated MAFLD. Mitochondria are dynamic cellular organelles capable of modifying their functions and structures to accommodate the metabolic demands of cells. In the context of MAFLD, the excess production of reactive oxygen species induces oxidative stress, leading to mitochondrial dysfunction, which subsequently promotes metabolic disorders, fat accumulation, and the infiltration of inflammatory cells in liver and adipose tissue. This review aims to systematically analyze the role of mitochondria-targeted therapies in MAFLD, evaluate current therapeutic strategies, and explore future directions in this rapidly evolving field. We specifically focus on the molecular mechanisms underlying mitochondrial dysfunction, emerging therapeutic approaches, and their clinical implications. This is of significant importance for the development of new therapeutic approaches for these metabolic disorders.

From "Burnt-Out" to "Burning-Out": Capturing Liver Fat Loss in Patients With Advanced Metabolic Dysfunction-Associated Steatotic Liver Disease From a Dynamic Perspective

BACKGROUND AND AIMS

The absence of hepatic fat in advanced fibrosis has been documented in metabolic dysfunction-associated steatotic liver disease (''burnt-out" MASLD). However, whether hepatic fat loss occurs continuously with fibrosis progression is controversial. We proposed a "burning-out" concept to describe this process and analyze the long-term outcomes of "burnt-out" and "burning-out" MASLD.

METHODS

We included a MASLD cohort from 16 centers, including 3273 individuals with baseline histology and 5455 with serial vibration-controlled transient elastography measurements during the follow-up. "Burnt-out" MASLD was defined by steatosis grade ≤S1 and fibrosis stage ≥F3. Trajectory analysis identified "burning-out" patients with continuous trends of decreasing controlled attenuation parameter and increasing liver stiffness measurement values.

RESULTS

Of 3273 patients with histologic evaluation included, 435 had "burnt-out" MASLD. Compared with those with pronounced steatosis in advanced fibrosis, patients with "burnt-out" had higher risks of all-cause mortality (hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.14-4.02), liver-related events (LREs; HR, 1.77; 95% CI, 1.12-2.78), and hepatic decompensation (HR, 1.83; 95% CI, 1.11-3.01). Of 5455 patients with vibration-controlled transient elastography included for trajectory analysis, 176 were identified as "burning-out" MASLD. The incidence rates of all-cause mortality, LREs, and decompensation were 7.28, 26.47, and 21.92 per 1000 person-years in "burning-out" patients, respectively. The "burning-out" group had higher cumulative incidences of adverse outcomes than patients with consistently high controlled attenuation parameter and moderate/low liver stiffness measurement values (P < .0001).

CONCLUSIONS

Continuous hepatic fat loss accompanied by fibrosis progression, referred to as "burning-out," was observed in advanced MASLD and associated with high rates of all-cause mortality, LREs, and hepatic decompensation.

Effect of high-intensity interval training on clinical parameters in patients with metabolic dysfunction-associated steatotic liver disease: a systematic review and meta-analysis of randomized controlled trials

High-intensity interval training (HIIT) has potential health benefits in the treatment of many chronic diseases. However, the efficacy of HIIT in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) remains unclear. This systematic review and meta-analysis aimed to assess the impact of HIIT on intrahepatic lipids (IHLs) , liver enzymes, and metabolic profiles in individuals with MASLD. All randomized-controlled trials (RCT) that evaluated and compared the effects of HIIT on clinical parameters in patients with MASLD were searched using the PubMed, EMBASE, WOS, and Cochrane databases. Data analysis and integration were performed using RevMan 5.3 (Cochrane Collaboration, Copenhagen, Denmark) and Stata version 18 software (StataCorp LLC, College Station, Texas, USA), and outcomes were assessed using the standardized mean difference (SMD). Our results showed that compared with other types of exercise or no exercise, HIIT could reduce the levels of IHL [SMD: -0.56%, 95% confidence interval (CI): -0.99 to -0.13, P = 0.01], BMI (SMD: -0.31, 95% CI: -0.62 to -0.01, P = 0.04), alanine aminotransferase (ALT) (SMD: -0.61, 95% CI: -0.95 to -0.26, P = 0.0006), and aspartate aminotransaminase (AST) (SMD: -0.43, 95% CI: -0.81 to -0.05, P = 0.03) in patients with MASLD. In addition, subgroup analyses showed that HIIT had a positive impact on clinical indicators in patients with MASLD with an intervention duration of less than equal to 8 weeks. This study supports the idea that HIIT can significantly reduce IHL, BMI, ALT, and AST levels, and further studies are needed to assess the long-term adherence and treatment effects of HIIT.

Pharmacological treatment for metabolic dysfunction-associated steatotic liver disease and related disorders: Current and emerging therapeutic options

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly known as nonalcoholic fatty liver disease) is a chronic liver disease affecting over a billion individuals worldwide. MASLD can gradually develop into more severe liver pathologies, including metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and liver malignancy. Notably, although being a global health problem, there are very limited therapeutic options against MASLD and its related diseases. While a thyroid hormone receptor agonist (resmetirom) is recently approved for MASH treatment, other efforts to control these diseases remain unsatisfactory. Given the projected rise in MASLD and MASH incidence, it is urgent to develop novel and effective therapeutic strategies against these prevalent liver diseases. In this article, the pathogenic mechanisms of MASLD and MASH, including insulin resistance, dysregulated nuclear receptor signaling, and genetic risk factors (eg, patatin-like phospholipase domain-containing 3 and hydroxysteroid 17-β dehydrogenase-13), are introduced. Various therapeutic interventions against MASH are then explored, including approved medication (resmetirom), drugs that are currently in clinical trials (eg, glucagon-like peptide 1 receptor agonist, fibroblast growth factor 21 analog, and PPAR agonist), and those failed in previous trials (eg, obeticholic acid and stearoyl-CoA desaturase 1 antagonist). Moreover, given that the role of gut microbes in MASLD is increasingly acknowledged, alterations in the gut microbiota and microbial mechanisms in MASLD development are elucidated. Therapeutic approaches that target the gut microbiota (eg, dietary intervention and probiotics) against MASLD and related diseases are further explored. With better understanding of the multifaceted pathogenic mechanisms, the development of innovative therapeutics that target the root causes of MASLD and MASH is greatly facilitated. The possibility of alleviating MASH and achieving better patient outcomes is within reach. SIGNIFICANCE STATEMENT: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide, and it can progress to more severe pathologies, including steatohepatitis, cirrhosis, and liver cancer. Better understanding of the pathogenic mechanisms of these diseases has facilitated the development of innovative therapeutic strategies. Moreover, increasing evidence has illustrated the crucial role of gut microbiota in the pathogenesis of MASLD and related diseases. It may be clinically feasible to target gut microbes to alleviate MASLD in the future.

Integrative Metabolism in MASLD and MASH: Pathophysiology and Emerging Mechanisms

The liver acts as a central metabolic hub, integrating signals from the gastrointestinal tract and adipose tissue to regulate carbohydrate, lipid, and amino acid metabolism. Gut-derived metabolites, such as acetate and ethanol and non-esterified fatty acids from white adipose tissue (WAT), influence hepatic processes, which rely on mitochondrial function to maintain systemic energy balance. Metabolic dysregulation from obesity, insulin resistance, and type 2 diabetes disrupt these pathways, leading to metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (MASH). This review explores the metabolic fluxes within the gut-adipose tissue-liver axis, focusing on the pivotal role of de novo lipogenesis (DNL), dietary substrates like glucose and fructose, and changes in mitochondrial function during MASLD progression. It highlights the contributions of white adipose tissue insulin resistance and impaired mitochondrial dynamics to hepatic lipid accumulation. Further understanding how the interplay between substrate flux from the gastro-intestinal tract integrates with adipose tissue and intersects with structural and functional alterations to liver mitochondria will be important to identify novel therapeutic targets and advance the treatment of MASLD and MASH.

P46Shc Inhibits Mitochondrial ACAA2 Thiolase, Exacerbating Mitochondrial Injury and Inflammation in Aging Livers

Mitochondrial maladaptation and dysfunction contribute to the progression of metabolic dysfunction-associated steatohepatitis (MASH). Induction of Shc is implicated in progressive MASH during aging and the cytoplasmic p52Shc isoform in the activation of redox enzyme NOX2. The mitochondrial Shc isoform p46Shc represses acetyl-coenzyme A acyltransferase 2 (ACAA2) in vitro. ACAA2 is a key enzyme for lipid β-oxidation; however, the metabolic consequences of in vivo p46Shc induction are unknown. In the current study, p46Shc-inducible mice were generated; these and littermate controls were aged and fed chow or fast-food (high-fat and high-fructose) diet. p46Shc induction increased liver injury, inflammation, and lipid peroxidation. p46Shc overexpression did not significantly change liver triglycerides. On electron microscopy studies, mitochondria were swollen with aberrant cristae. p46Shc induction reduced mitochondrial oxygen consumption as measured by Oroboros, as well as suppressed the production of β-hydroxybutyrate, the central metabolite of therapeutic ketosis. Mitochondria exhibited increased production of reactive oxidative species. By contrast, the expression of dominant negative p46Shc reduced ACAA2 thiolase activity, improved β-oxidation, and reduced lipid peroxidation and production of reactive oxidative species. In summary, these studies support the concept that p46Shc induction in aging represses ACAA2, resulting in decreased mitochondrial β-oxidation and increased lipid peroxidation. Maintaining β-oxidation and ketogenesis could prevent liver injury, and targeting Shc-related maladaptive responses could be a successful therapeutic strategy in aging/MASH.

The Management of Cardiometabolic Risk in MAFLD: Therapeutic Strategies to Modulate Deranged Metabolism and Cholesterol Levels

Background and Objectives: Fatty Liver Disease is a major health problem worldwide. We can distinguish liver steatosis as non-associated or associated with chronic/acute alcohol consumption. These two entities share similar stages ranging from hepatic fat storage (namely, steatosis) to inflammation, necrosis, and fibrosis until hepatocellular carcinoma (HCC). Over time, "Metabolic Associated Fatty Liver Disease" (MAFLD) has replaced nonalcoholic fatty liver disease (NAFLD) nomenclature and has included cardiometabolic criteria in these patients definition. Thus, obesity, type 2 diabetes mellitus (T2DM), hypertension, and dyslipidemia are MAFLD features and are of the metabolic syndrome. Importantly, there is not a specific treatment for MAFLD, but there are therapeutic strategies that act on metabolic dysfunction related to MAFLD. They can reduce the progression of liver fibrosis and its complications. Materials and Methods: For all these reasons, we conducted a narrative review of the literature, and we focused on metabolic dysfunction related to MAFLD, with a special regard for cholesterol metabolism. Results: MAFLD is a recently redefined condition that better describes the metabolism derangement responsible for fatty liver disease. This distinguishes MAFLD from NAFLD. In fact, the diagnostic criteria for MAFLD require the presence of liver steatosis together with at least one of the following: obesity, T2DM, or evidence of metabolic disorder such as hypertriglyceridemia, low high-density lipoprotein cholesterol, or hypertension. As a result, MAFLD is closely linked to an increased cardiometabolic risk. Current therapeutic approaches can be used to reduce this risk, focusing on lifestyle interventions and pharmacological strategies. Several treatments in patients diagnosed with MAFLD are mainly cholesterol-lowering remedies. Among these, Pro-protein Convertase Subtilisin/Kexin type 9 inhibitors (PCSK9i) show the most promising efficacy profile but data on liver fibrosis are lacking. Agonists of GLP-1 receptor, Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and Dipeptidyl Peptidase-4 inhibitors (DPP-4i) have a " multi-hit " action allowing their use also in diabetic patients with MAFLD. Conclusions: Lifestyle modifications, some nutraceuticals, statins, incretins, and PCSK9i have changed the natural course and significantly improved the cardiometabolic outcomes of MAFLD. Emerging cholesterol-lowering drugs, such as Bempedoic acid, can overcome low compliance to statins' use and their controversial effect on liver fibrosis. Finally, medications targeting insulin resistance allow for strategic interventions of the convoluted pathophysiology of MAFLD in multiple steps, with the potential to reduce liver steatosis, inflammation, and necrosis and, sometimes even to reverse liver fibrosis.

Functional compartmentalization of hepatic mitochondrial subpopulations during MASH progression

The role of peridroplet mitochondria (PDM) in diseased liver, such as during the progression of metabolic dysfunction-associated steatohepatitis (MASH), remains unknown. We isolated hepatic cytoplasmic mitochondria (CM) and PDM from a mouse model of diet-induced MASLD/MASH to characterize their functions from simple steatosis to advanced MASH, using chow-fed mice as controls. Our findings show an inverse relationship between hepatic CM and PDM levels from healthy to steatosis to advanced MASH. Proteomics analysis revealed these two mitochondrial populations are compositionally and functionally distinct. We found that hepatic PDM are more bioenergetically active than CM, with higher pyruvate oxidation capacity in both healthy and diseased liver. Higher respiration capacity of PDM was associated with elevated OXPHOS protein complexes and increased TCA cycle flux. In contrast, CM showed higher fatty acid oxidation capacity with MASH progression. Transmission electron microscopy revealed larger and elongated mitochondria during healthy and early steatosis, which appeared small and fragmented during MASH progression. These changes coincided with higher MFN2 protein levels in hepatic PDM and higher DRP1 protein levels in hepatic CM. These findings highlight the distinct roles of hepatic CM and PDM in MASLD progression towards MASH.

Lubiprostone Reduces Fat Content on MRI-PDFF in Patients With MASLD: A 48-Week Randomised Controlled Trial

BACKGROUND AND AIMS

The laxative lubiprostone has been shown to decrease intestinal permeability. We aimed to assess the safety and efficacy of lubiprostone administered for 48 weeks in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

APPROACH AND RESULTS

A randomised placebo-controlled trial was conducted in a specialised MASLD outpatient clinic at the National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt. The recruited patients had radiological evidence of MASLD along with other criteria for diagnosis. Eligible patients were randomly assigned to receive either placebo or lubiprostone 24 μg orally twice daily for 48 weeks. The liver fat content was quantified by magnetic resonance imaging estimated proton density fat fraction (MRI-PDFF). Between November 2020 and February 2023, 176 patients were screened, of whom 116 were eligible. Fifty-nine patients were randomised to receive placebo, while 57 patients were randomised to receive lubiprostone. Due mostly to patient dropout (i.e., loss to follow-up), complete data were available for 40 patients in each group. Compared with placebo group, 48-week lubiprostone treatment significantly reduced fat quantity (p = 0.04). Despite a significant reduction in body weight in the control group, no significant difference was found between both groups regarding fibrosis score by transient elastography or in serum ALT levels. One patient in the lubiprostone group developed severe diarrhoea requiring treatment stoppage. No other serious adverse events occurred.

CONCLUSION

Lubiprostone was well tolerated and reduced liver fat content as measured by MRI-PDFF in patients with MASLD over 48 weeks. Lubiprostone appears promising to treat MASLD and warrants more extensive studies to confirm such efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05768334.

Heat-Processed Diet Rich in Advanced Glycation End Products Induced the Onset and Progression of NAFLD via Disrupting Gut Homeostasis and Hepatic Lipid Metabolism

Epidemiologic studies have suggested an association between the consumption of dietary advanced glycation end products (dAGEs) and the incidence of nonalcoholic fatty liver disease (NAFLD). However, the precise mechanism by which dAGEs induce NAFLD development, particularly the pathogenic role of the gut-liver axis, remains poorly understood. In this study, by establishing a high-AGE diet (HAD)-fed C57BL/6 mouse model, we employed multiomics approaches combined with a series of biological analyses to investigate the effect of HAD on NAFLD in vivo. Our results showed that exposure to HAD led to fat accumulation, oxidative stress, inflammation, and fibrosis in the liver of mice. Transcriptome analysis further revealed that HAD exposure disrupted lipid metabolism and activated inflammation-related signaling pathways in the liver. Additionally, exposure to HAD induced perturbations in gut homeostasis, as evidenced by the compromised gut barrier function, reduced probiotic abundance, and increases in pathogenic bacterial proportions. Dysbiosis of gut homeostasis may further act as a trigger for the initiation and progression of NAFLD via the gut-liver axis. This study sheds light on the underlying mechanisms through which dAGEs contribute to the development of NAFLD and helps to understand the detrimental effects of food ultraprocessing products in modern diets. Future studies are needed to explore the in-depth mechanisms related to the gut-liver axis to consolidate our conclusions.

Establishing of a risk prediction model for metabolic dysfunction-associated steatotic liver disease: a retrospective cohort study

OBJECTIVES

Over 30% of people worldwide suffer from metabolic dysfunction-associated steatotic liver disease (MASLD), a significant global health issue. Identifying and preventing high-risk individuals for MASLD early is crucial. The purpose of our study is to investigate the factors related to the development of MASLD and develop a risk prediction model for its occurrence.

METHODS

The study included 5107 subjects, divided into training and validation groups in a 7:3 ratio using a random number table method. Collinearity diagnosis and Cox regression were used to identify factors associated with MASLD incidence, and a risk prediction model was created. The model's accuracy, reliability, and clinical applicability were assessed.

RESULTS

Our study indicated that male, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting plasma glucose (FPG), serum uric acid to creatinine ratio (SUA/Cr) and white blood cell (WBC) were associated with MASLD incidence. The elements were determined to be crucial for creating a risk prediction model. The model showed strong discriminative potential with a C-index of 0.783 and the time-dependent AUCs of 0.781, 0.789, 0.814 and 0.796 for 1-4 years in the training group, and a C-index of 0.788 and the time-dependent AUCs of 0.798, 0.782, 0.787 and 0.825 for 1-4 years in validation. Calibration curves confirmed the model's accuracy, and decision curve analysis (DCA) validated its clinical utility.

CONCLUSIONS

The model may provide clinical physicians with a reliable method for identifying high-risk populations for MASLD and serve as a guide for developing prediction models for other diseases.

The activity of a herbal medicinal product of Phyllanthus niruri and Silybum marianum powdered extracts (Heptex®) in patients with apparent risk factors for nonalcoholic steatohepatitis: a phase II, multicentered, randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease (NAFLD) characterized by damage and inflammation of hepatocytes. Some medicinal plants have shown antioxidant and anti-inflammatory effects on liver cells. We aimed to investigate the hepatoprotective effect of Heptex® capsules containing 200 mg of Dukung Anak (a powdered extract from aerial parts of Phyllanthus niruri) and 100 mg of Milk Thistle (a powdered extract from fruits of Silybum marianum) in patients with an apparent risk factor for NASH.

METHODS

This was a phase II, randomized, double-blind, placebo-controlled, three-arm, interventional clinical trial. Patients were randomized in a 1:1:1 ratio to receive placebo, low dose (one capsule) of Heptex®, or high dose (two capsules) of Heptex®. After 36 weeks, liver enzymes, Fib-4 score, lipid profile, CAP score, and kPa score were evaluated. Patients were monitored for safety throughout the treatment duration.

RESULTS

A total of 146 patients were enrolled in the study. A significant decrease was observed in ALT levels in the low-dose group (57 IU/L to 40 IU/L, p = 0.026) and the high-dose group (61 IU/L to 47.5 IU/L, p < 0.0001) and in AST levels in the high-dose group (43.5 IU/L to 32 IU/L, p = 0.001), with no significant difference between the relative percent change in ALT (p = 0.465) or AST (p = 0.632) between the three groups. No significant difference was revealed between the three groups regarding the median change in Fib-4 score at the end of treatment (p = 0.985). No significant change in the lipid profile was observed in any of the three groups except for the total cholesterol level, which significantly decreased from 210 IU/L to 187 IU/L, p = 0.031 in the low-dose group.

CONCLUSION

Heptex® capsules were safe and well tolerated over a treatment period of 36 weeks. However, the hepatoprotective effect in patients at risk of NASH still needs further assessment using more accurate investigation tools, a larger sample size, and/ or higher doses of the combination.

TRIAL REGISTRATION

Retrospectively registered (registration date: 25/04/2022; trial registration number: NCT05343780).

Metabolic dysfunction-associated steatotic liver disease-induced changes in the antioxidant system: a review

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a heterogeneous condition characterized by liver steatosis, inflammation, consequent fibrosis, and cirrhosis. Chronic impairment of lipid metabolism is closely related to oxidative stress, leading to cellular lipotoxicity, mitochondrial dysfunction, and endoplasmic reticulum stress. The detrimental effect of oxidative stress is usually accompanied by changes in antioxidant defense mechanisms, with the alterations in antioxidant enzymes expression/activities during MASLD development and progression reported in many clinical and experimental studies. This review will provide a comprehensive overview of the present research on MASLD-induced changes in the catalytic activity and expression of the main antioxidant enzymes (superoxide dismutases, catalase, glutathione peroxidases, glutathione S-transferases, glutathione reductase, NAD(P)H:quinone oxidoreductase) and in the level of non-enzymatic antioxidant glutathione. Furthermore, an overview of the therapeutic effects of vitamin E on antioxidant enzymes during the progression of MASLD will be presented. Generally, at the beginning of MASLD development, the expression/activity of antioxidant enzymes usually increases to protect organisms against the increased production of reactive oxygen species. However, in advanced stage of MASLD, the expression/activity of several antioxidants generally decreases due to damage to hepatic and extrahepatic cells, which further exacerbates the damage. Although the results obtained in patients, in various experimental animal or cell models have been inconsistent, taken together the importance of antioxidant enzymes in MASLD development and progression has been clearly shown.

Diverting hepatic lipid fluxes with lifestyles revision and pharmacological interventions as a strategy to tackle steatotic liver disease (SLD) and hepatocellular carcinoma (HCC)

Steatotic liver disease (SLD) and Hepatocellular Carcinoma (HCC) are characterised by a substantial rewiring of lipid fluxes caused by systemic metabolic unbalances and/or disrupted intracellular metabolic pathways. SLD is a direct consequence of the interaction between genetic predisposition and a chronic positive energy balance affecting whole-body energy homeostasis and the function of metabolically-competent organs. In this review, we discuss how the impairment of the cross-talk between peripheral organs and the liver stalls glucose and lipid metabolism, leading to unbalances in hepatic lipid fluxes that promote hepatic fat accumulation. We also describe how prolonged metabolic stress builds up toxic lipid species in the liver, and how lipotoxicity and metabolic disturbances drive disease progression by promoting a chronic activation of wound healing, leading to fibrosis and HCC. Last, we provide a critical overview of current state of the art (pre-clinical and clinical evidence) regarding mechanisms of action and therapeutic efficacy of candidate SLD treatment options, and their potential to interfere with SLD/HCC pathophysiology by diverting lipids away from the liver therefore improving metabolic health.

Ketogenesis protects against MASLD-MASH progression through mechanisms that extend beyond overall fat oxidation rate

The progression of metabolic-dysfunction-associated steatotic liver disease (MASLD) to metabolic-dysfunction-associated steatohepatitis (MASH) involves complex alterations in both liver-autonomous and systemic metabolism that influence the liver's balance of fat accretion and disposal. Here, we quantify the relative contribution of hepatic oxidative pathways to liver injury in MASLD-MASH. Using NMR spectroscopy, UHPLC-MS, and GC-MS, we performed stable-isotope tracing and formal flux modeling to quantify hepatic oxidative fluxes in humans across the spectrum of MASLD-MASH, and in mouse models of impaired ketogenesis. We found in humans with MASH, that liver injury correlated positively with ketogenesis and total fat oxidation, but not with turnover of the tricarboxylic acid cycle. The use of loss-of-function mouse models demonstrated that disruption of mitochondrial HMG-CoA synthase (HMGCS2), the rate-limiting step of ketogenesis, impairs overall hepatic fat oxidation and induces a MASLD-MASH-like phenotype. Disruption of mitochondrial β-hydroxybutyrate dehydrogenase (BDH1), the terminal step of ketogenesis, also impaired fat oxidation, but surprisingly did not exacerbate steatotic liver injury. Taken together, these findings suggest that quantifiable variations in overall hepatic fat oxidation may not be a primary determinant of MASLD-to-MASH progression, but rather, that maintenance of hepatic ketogenesis could serve a protective role through additional mechanisms that extend beyond quantified overall rates of fat oxidation.

Lipid metabolism in MASLD and MASH: From mechanism to the clinic

Metabolic dysfunction-associated steatotic liver disease/steatohepatitis (MASLD/MASH) is recognised as a metabolic disease characterised by excess intrahepatic lipid accumulation due to lipid overflow and synthesis, alongside impaired oxidation and/or export of these lipids. But where do these lipids come from? The main pathways related to hepatic lipid accumulation are de novo lipogenesis and excess fatty acid transport to the liver (due to increased lipolysis, adipose tissue insulin resistance, as well as excess dietary fatty acid intake, in particular of saturated fatty acids). Not only triglycerides but also other lipids are secreted by the liver and are associated with a worse histological profile in MASH, as shown by lipidomics. Herein, we review the role of lipid metabolism in MASLD/MASH and discuss the impact of weight loss (diet, bariatric surgery, GLP-1RAs) or other pharmacological treatments (PPAR or THRβ agonists) on hepatic lipid metabolism, lipidomics, and the resolution of MASH.

Sensitive Profiling of Mouse Liver Membrane Proteome Dysregulation Following a High-Fat and Alcohol Diet Treatment

Alcohol consumption and high-fat (HF) diets often coincide in Western society, resulting in synergistic negative effects on liver function. Although studies have analyzed the global protein expression in the context of alcoholic liver disease (ALD) and metabolic dysfunction-associated steatotic liver disease (MASLD), none has offered specific insights on liver dysregulation at the membrane proteome level. Membrane-specific profiling of metabolic and compensatory phenomena is usually overshadowed in conventional proteomic workflows. In this study, we use the Peptidisc method to isolate and compare the membrane protein (MP) content of the liver with its unique biological functions. From mice fed with an HF diet and ethanol in drinking water, we annotate over 1500 liver proteins with half predicted to have at least one transmembrane segment. Among them, we identify 106 integral MPs that are dysregulated compared to the untreated sample. Gene Ontology analysis reveals several dysregulated membrane-associated processes like lipid metabolism, cell adhesion, xenobiotic processing, and mitochondrial membrane formation. Pathways related to cholesterol and bile acid transport are also mutually affected, suggesting an adaptive mechanism to counter the upcoming steatosis of the liver model. Taken together, our Peptidisc-based profiling of the diet-dysregulated liver provides specific insights and hypotheses into the role of the transmembrane proteome in disease development, and flags desirable MPs for therapeutic and diagnostic targeting.

Hepatic glucose production rises with the histological severity of metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (MASH) are associated with a high prevalence of type 2 diabetes (T2D). Individuals with MASLD exhibit insulin resistance (IR) and hyperglycemia, but it is unclear whether hepatic glucose production (HGP) is increased with MASLD severity. We evaluated HGP in a cohort of histologically characterized individuals with MASL/MASH using stable isotope infusion (6,6-2H2-glucose, U-2H5-glycerol) and liver-specific genome-scale metabolic models (GEMs). Tracer-measured HGP is increased with liver fibrosis and inflammation, but not steatosis, and is associated with lipolysis and IR. The GEM-derived gluconeogenesis is elevated due to high glucogenic/energy metabolite uptakes (lactate, glycerol, and free fatty acid [FFA]), and the expression of insulin action genes (IRS1, IRS2, and AKT2) is reduced in MASH with fibrosis F2-F4, with/without T2D, suggesting these as putative mechanisms for increased fasting HGP and hyperglycemia. In conclusion, elevated HGP, lipolysis, and IR help to explain the mechanisms for the increased risk of hyperglycemia and T2D in MASH.

Glucagon promotes increased hepatic mitochondrial oxidation and pyruvate carboxylase flux in humans with fatty liver disease

We assessed in vivo rates of hepatic mitochondrial oxidation, gluconeogenesis, and β-hydroxybutyrate (β-OHB) turnover by positional isotopomer NMR tracer analysis (PINTA) in individuals with metabolic-dysfunction-associated steatotic liver (MASL) (fatty liver) and MASL disease (MASLD) (steatohepatitis) compared with BMI-matched control participants with no hepatic steatosis. Hepatic fat content was quantified by localized 1H magnetic resonance spectroscopy (MRS). We found that in vivo rates of hepatic mitochondrial oxidation were unaltered in the MASL and MASLD groups compared with the control group. A physiological increase in plasma glucagon concentrations increased in vivo rates of hepatic mitochondrial oxidation by 50%-75% in individuals with and without MASL and increased rates of glucose production by ∼50% in the MASL group, which could be attributed in part to an ∼30% increase in rates of mitochondrial pyruvate carboxylase flux. These results demonstrate that (1) rates of hepatic mitochondrial oxidation are not substantially altered in individuals with MASL and MASLD and (2) glucagon increases rates of hepatic mitochondrial oxidation.

Histological improvements following energy restriction and exercise: The role of insulin resistance in resolution of MASH

BACKGROUND & AIMS

Metabolic dysfunction-associated steatohepatitis (MASH) is one of the most common liver diseases worldwide and is characterized by multi-tissue insulin resistance. The effects of a 10-month energy restriction and exercise intervention on liver histology, anthropometrics, plasma biochemistries, and insulin sensitivity were compared to standard of care (control) to understand mechanisms that support liver health improvements.

METHODS

Following medical diagnosis of MASH, individuals were randomized to treatment (n = 16) or control (n = 8). Liver fat (magnetic resonance spectroscopy), 18-hour plasma biochemical measurements, and isotopically labeled hyperinsulinemic-euglycemic clamps were completed pre- and post-intervention. Body composition and cardiorespiratory fitness (VO2peak) were also measured mid-intervention. Those in the treatment group were counseled to reduce energy intake and completed supervised, high-intensity interval training (3x/week) for 10 months. Controls continued physician-directed care.

RESULTS

Treatment induced significant (p <0.05) reductions in body weight, fat mass, and liver injury, while VO2peak (p <0.05) and non-esterified fatty acid suppression (p = 0.06) were improved. Both groups exhibited reductions in total energy intake, hemoglobin A1c, hepatic insulin resistance, and liver fat (p <0.05). Compared to control, treatment induced a two-fold increase in peripheral insulin sensitivity which was significantly related to higher VO2peak and resolution of liver disease.

CONCLUSIONS

Exercise and energy restriction elicited significant and clinically meaningful treatment effects on liver health, potentially driven by a redistribution of excess nutrients to skeletal muscle, thereby reducing hepatic nutrient toxicity. Clinical guidelines should emphasize the addition of aerobic exercise in lifestyle treatments for the greatest histologic benefit in individuals with advanced MASH.

IMPACT AND IMPLICATIONS

The mechanisms that underpin histologic improvement in individuals with metabolic dysfunction-associated steatohepatitis (MASH) are not well understood. This study evaluated the relationship between liver and metabolic health, testing how changes in one may affect the other. We investigated the effects of energy restriction and exercise on the association between multi-tissue insulin sensitivity and histologic improvements in participants with biopsy-proven MASH. For the first time, these results show that an improvement in peripheral (but not hepatic) insulin sensitivity and systemic markers of muscle function (i.e. cardiorespiratory fitness) were strongly related to resolution of liver disease. Extrahepatic disposal of substrates and improved fitness levels supported histologic improvement, confirming the addition of exercise as crucial to lifestyle interventions in MASH.

CLINICAL TRIAL NUMBER

NCT03151798.

Down-regulation of miR-29 improves lipid metabolism in fatty liver of dairy cows

In this study, we conducted a thorough investigation into the mechanisms by which miR-29 influences lipid metabolism. Thirty-two cows were selected and categorized into distinct groups based on their liver triglyceride (TG) content: healthy, mild fatty liver, and moderate fatty liver groups. Dairy cows with moderate fatty liver showed higher levels of hepatic lipid accumulation, MDA content and serum AST, ALT and ALP contents and lower hepatic catalase CAT and SOD activities. Subsequently, hepatocytes isolated from healthy calves were exposed to sodium oleate (SO) in the presence or absence of pre-incubation with miR-29 inhibitor or inhibitor NC. Pre-transfection with miR-29 inhibitor resulted in reduced hepatocyte lipid accumulation and MDA levels, as well as decreased levels of AST, ALT, and ALP in the supernatant. In the miR-29 inhibitor + SO group, there was an increase in the expression of SREBP-1, FAS, SCD1, and Sirt1. Meanwhile, the expression of PPARα, CPT1, CPT2, PGC-1α, NRF-1, UCP2, and miR-29 were observed to be decreased. In comparison to the miR-29 inhibitor + SO group, some of the measured indicators showed partial reversal in the miR-29 inhibitor + siSirt1 + SO group. Collectively, these findings provide evidence that miR-29 may play a crucial role in the pathogenesis of fatty liver in dairy cows.

Hepatokines and MASLD: The GLP1-Ras-FGF21-Fetuin-A Crosstalk as a Therapeutic Target

The introduction of the term "Metabolic Steatotic Liver Disease" (MASLD) underscores the critical role of metabolic dysfunction in the development and progression of chronic liver disease and emphasizes the need for strategies that address both liver disease and its metabolic comorbidities. In recent years, a liver-focused perspective has revealed that altered endocrine function of the fatty liver is a key contributor to the metabolic dysregulation observed in MASLD. Due to its secretory capacity, the liver's increased production of proteins known as "hepatokines" has been linked to the development of insulin resistance, explaining why MASLD often precedes dysfunction in other organs and ultimately contributes to systemic metabolic disease. Among these hepatokines, fibroblast growth factor 21 (FGF21) and fetuin-A play central roles in regulating the metabolic abnormalities associated with MASLD, explaining why their dysregulated secretion in response to metabolic stress has been implicated in the metabolic abnormalities of MASLD. This review postulates why their modulation by GLP1-Ras may mediate the beneficial metabolic effects of these drugs, which have increased attention to their emerging role as pharmacotherapy for MASLD. By discussing the crosstalk between GLP1-Ras-FGF21-fetuin-A, this review hypothesizes that the possible modulation of fetuin-A by the novel GLP1-FGF21 dual agonist pharmacotherapy may contribute to the management of metabolic and liver diseases. Although research is needed to go into the details of this crosstalk, this topic may help researchers explore the mechanisms by which this type of pharmacotherapy may manage the metabolic dysfunction of MASLD.

Beneficial effects of MGL-3196 and BAM15 combination in a mouse model of fatty liver disease

BACKGROUND AND AIM

Metabolic dysfunction-associated steatohepatitis (MASH) is a metabolic disorder with limited treatment options. The thyroid hormone receptor (THR)-β agonist resmetirom/MGL-3196 (MGL) increases liver fat oxidation and has been approved for treating adult MASH. However, over 60% of patients receiving MGL treatment do not achieve MASH resolution. Therefore, we investigated the potential for combination therapy of MGL with the mitochondrial uncoupler BAM15 to improve fatty liver disease outcomes in the GAN mouse model of MASH.

METHODS

C57BL/6J male mice were fed GAN diet for 38 weeks before stratification and randomization to treatments including MGL, BAM15, MGL + BAM15, or no drug control for 8 weeks. Treatments were admixed in diet and mice were pair-fed to control for drug intake. Treatment effectiveness was assessed by body weight, body composition, energy expenditure, glucose tolerance, tissue lipid content, and histological analyses.

RESULTS

MGL + BAM15 treatment resulted in better efficacy versus GAN control mice than either monotherapy in the context of energy expenditure, liver fat loss, glucose control, and fatty liver disease activity score. Improvements in ALT, liver mass, and plasma cholesterol were primarily driven by MGL, while improvements in body fat were primarily driven by BAM15. No treatments altered liver fibrosis.

CONCLUSIONS

MGL + BAM15 treatment had overall better efficacy to improve metabolic outcomes in mice fed GAN diet than either monotherapy alone. These data warrant further investigation into combination therapies of THR-β agonists and mitochondrial uncouplers for the potential treatment of disorders related to fatty liver, obesity, and insulin resistance.

Machine-Learning Application for Predicting Metabolic Dysfunction-Associated Steatotic Liver Disease Using Laboratory and Body Composition Indicators

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a significant global health burden without established curative therapies. Early detection and preventive strategies are crucial for effective MASLD management. This study aimed to develop and validate machine-learning (ML) algorithms for accurate MASLD screening in a geographically diverse, large-scale population.

METHODS

Data from the prospective Fasa Cohort Study, initiated in rural Fars province, Iran (March 2014), were employed for this purpose. The required data were collected using blood tests, questionnaires, liver ultrasonography, and physical examinations. A two-step approach identified key predictors from over 100 variables: (1) statistical selection using mean decrease Gini in random forest and (2) incorporation of clinical expertise for alignment with known MASLD risk factors. The hold-out validation approach (with a 70/30 train/validation split) was utilized, along with 5-fold cross-validation on the validation set. Logistic regression, Naïve Bayes, support vector machine, and light gradient-boosting machine (LightGBM) algorithms were compared for model construction with the same input variables based on area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy.

RESULTS

A total of 6,180 adults (52.7% female) were included in the study, categorized into 4816 non-MASLD and 1364 MASLD cases with a mean age (±standard deviation [SD]) of 48.12 (±9.61) and 49.47 (±9.15) years, respectively. Logistic regression outperformed other ML algorithms, achieving an accuracy of 0.88 (95% confidence interval [CI]: 0.86-0.89) and an AUC of 0.92 (95% CI: 0.90-0.93). Among more than 100 variables, the key predictors included waist circumference, body mass index (BMI), hip circumference, wrist circumference, alanine aminotransferase levels, cholesterol, glucose, high-density lipoprotein, and blood pressure.

CONCLUSION

Integration of ML in MASLD management holds significant promise, particularly in resource-limited rural settings. Additionally, the relative importance assigned to each predictor, particularly prominent contributors such as waist circumference and BMI, offers valuable insights into MASLD prevention, diagnosis, and treatment strategies.

Fatty acid oxidation-induced HIF-1α activation facilitates hepatic urate synthesis through upregulating NT5C2 and XDH

Dyslipidemia affects approximately half of all people with gout, and prior Mendelian randomization analysis suggested a causal role for elevated triglycerides in hyperuricemia (HU), but the underlying mechanisms remain elusive. We hypothesize that dyslipidemia promotes hepatic urate biosynthesis in HU and gout and fatty acid (FA) oxidation (FAO) drives this process. Here we developed a targeted metabolomics to quantify major metabolites in purine metabolic pathway in the sera of a human cohort with HU, gout, and normaluricemic controls. We found that the levels of major purine metabolites and multiple FAs were significantly elevated in HU and gout groups compared to normouricemic controls, whereas hypoxathine showed opposite trend. Furthermore, the levels of multiple serum FAs were positively correlated with urate, xanthine, and inosine but negatively with hypoxanthine, which was also observed in a murine model of high-fat diet-induced HU. Using a stable isotope-labeled metabolic flux assay, we discovered that exogenous hypoxanthine plays a key role in urate synthesis. Moreover, FAO-induced hypoxia-inducible factor 1 alpha (HIF-1α) activation upregulated 5'-nucleotidase II (NT5C2) and xanthine dehydrogenase (XDH) levels to facilitate hypoxanthine uptake from the blood to the liver and activation of urate biosynthesis. Our findings were further supported by data in human hepatocytes and 50 paired serum and liver tissues from liver transplant donors. Together, this study uncovers a mechanism by which FAO promotes hepatic urate synthesis by activating HIF-1α-NT5C2/XDH pathways, directly linking lipid metabolism to HU.

Subcellular expression of CYP2E1 in HepG2 cells impacts response to free oleic and palmitic acid

Aims

Cytochrome P450 2E1 (CYP2E1) is a mammalian monooxygenase expressed at high levels in the liver that metabolizes low molecular weight pollutants and drugs, as well as endogenous fatty acids and ketones. Although CYP2E1 has been mainly studied in the endoplasmic reticulum (ER, microsomal fraction), it also localizes in significant amounts to the mitochondria, where it has been far less studied. We investigated the effects of CYP2E1 expression in mitochondria, endoplasmic reticulum, or both organelles in transgenic HepG2 cells exposed to free oleic and palmitic acid, including effects on cytotoxicity, lipid storage, respiration, and gene expression.

Results

We found that HepG2 cells expressing CYP2E1 in both the ER and mitochondria have exacerbated levels of palmitic acid cytotoxicity and inhibited respiration. CYP2E1 expression did not impact lipid accumulation from fatty acid exposures, but mitochondrial CYP2E1 expression promoted lipid droplet depletion during serum starvation. In contrast to HepG2 cells, differentiated HepaRG cells express abundant CYP2E1, but they are not sensitive to palmitic acid cytotoxicity. Oleic acid exposure prompted less cytotoxicity, and CYP2E1 expression in the ER prevented an oleic-acid-induced increase in respiration. HepG2 cells exposed to mixtures of palmitic and oleic acid are protected from palmitic acid cytotoxicity. Additionally, we identified that CYP2E1 was decreased at the gene and protein level in hepatocellular carcinoma. Moreover, patients with tumors that had higher CYP2E1 expression had a better prognosis compared to patients with lower CYP2E1 expression.

Innovation

This study has demonstrated that transgenic CYP2E1 subcellular localization plays an important role in sensitivity to cytotoxicity, lipid storage, and respiration in the hepatoma cell line HepG2 exposed to palmitic and oleic acid. HepaRG cells, in contrast, were insensitive to palmitic acid. This work demonstrates the clear importance of CYP2E1 in dictating lipotoxicity and differential roles for the mitochondrial and ER forms of the enzyme. Additionally, our data supports a potentially unique role for CYP2E1 in cancer cells.

Conclusion

There lies a role for CYP2E1 in altering lipotoxicity, and since CYP2E1 is known to be upregulated in both liver disease and hepatocellular carcinoma, it is important to better define how the role of CYP2E1 changes during disease progression.

A Prospective Randomised Comparative Four-arm Intervention Study of Efficacy and Safety of Saroglitazar and Vitamin E in Patients With Non-alcoholic Fatty Liver Disease (NAFLD)/Non-alcoholic Steatohepatitis (NASH)-SVIN TRIAL

Background and aim

Vitamin E is widely prescribed for non-alcoholic steatohepatitis (NASH). Saroglitazar, a novel dual peroxisome proliferator-activator receptor ɑ/γ agonist, is approved in India for non-alcoholic fatty liver disease (NAFLD). No head-to-head comparative study for vitamin E and saroglitazar is available. We studied the efficacy and safety of saroglitazar and vitamin E in NAFLD/NASH.

Materials and methods

We prospectively randomised 175 NAFLD patients into four arms as Saroglitazar 4 mg daily alone (n = 44), vitamin E 800IU daily alone (n = 41), vitamin E and saroglitazar combination (n = 47), and control arm (n = 43). All the baseline variables including liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) were recorded. Reassessment was done after 24 weeks of treatment.

Results

The mean age and body mass index was 45 ± 11 years and 26 ± 3.6 kg/m2, respectively. Compared to control, the decrease in alanine amino transferase levels with saroglitazar, vitamin E, and combination therapy was significant (95% confidence interval [CI]: 6.27-28.25, P = 0.002, 95% CI: -3.39 to 18.88, P = 0.047 and 95% CI: 8.10-29.54, P = 0.001, respectively). The reduction in CAP was significant with saroglitazar and combination therapy (95% CI: -31.94 to 11.99, P = 0.015 and 95% CI: -10.48 to 30.51, P = 0.026, respectively). Only combination therapy shows significant reduction in LSM (95% CI: 0.41-1.68, P = 0.001). Among glycaemic parameters, both saroglitazar alone and combination therapy significantly improved glycosylated haemoglobin levels (P = 0.001 and P = 0.015, respectively), and only combination therapy significantly improved homoeostasis model assessment-estimated insulin resistance (P = 0.047). Saroglitazar alone showed significant reduction in triglyceride and low-density lipoprotein levels (P = 0.038 and P = 0.018, respectively), and combination therapy showed significant increase in high-density lipoprotein levels (P = 0.024).

Conclusions

Combination of Saroglitazar and vitamin E showed statistically significant reduction of LSM and CAP along with biochemical, glycaemic, and lipid parameters.

Clinical trial registry India no

CTRI/2022/01/039538.

Efficacy and safety of Resmetirom, a selective thyroid hormone receptor-β agonist, in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD): a systematic review and meta-analysis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an important public health problem owing to its high prevalence and associated morbidity and mortality secondary to progressive liver disease and cardiovascular events. Resmetirom, a selective thyroid hormone receptor-β agonist has been developed as a therapeutic modality for MASLD. This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of resmetirom compared to a placebo in the treatment of MASLD. Eligible studies were systematically identified by screening PubMed, Scopus, Web of Science, Cochrane library, Embase, and ClinicalTrials.gov from 2014 to 2024. Only randomized controlled trials comparing the efficacy and safety of resmetirom in the treatment of MASLD against placebo were included in the analysis. Meta-analysis was performed using RevMan 5.4 software. Four studies with low risk of bias and involving a total of 2359 participants were identified. The metanalysis included only three clinical trials with 2234 participants. A significant reduction in MRI-proton density fat fraction (MRI-PDFF) with 80 mg Resmetirom compared to that with placebo [SMD - 27.74 (95% CI - 32.05 to - 32.42), p < 0.00001] at 36-52 weeks as well as at 12-16 weeks [SMD - 30.92 (95% CI - 36.44 to - 25.40), p < 0.00001]. With Resmetirom 100 mg dose at 36-52 weeks [SMD - 36.05 (95% CI - 40.67 to - 31.43), p < 0.00001] and 12-16 weeks [SMD - 36.89 (95% CI - 40.73 to - 33.05), p < 0.00001] were observed. Resmetirom treatment was associated with a significant reduction in LDL-c triglyceride, lipoproteins. and liver enzymes. There was significant reduction FT4 and increase in SHBG and sex steroids with Resmetirom compared to placebo. There was no major difference in the overall treatment emergent adverse events at 80 mg [OR 1.55 (95% CI 0.84 to 2.87), and 100 mg [OR 1.13 (95% CI 0.78 to 1.63), doses of Resmetirom compared to placebo. However, gastrointestinal adverse events diarrhoea and nausea occurred in ≥ 10% in the Resmetirom group compared to placebo at < 12 week. Resmetirom treatment showed modest efficacy in treating MASLD with reduction in MRI-PDFF, LDL-c, triglyceride, lipoproteins, liver enzymes and NASH biomarkers without significant safety concerns. Larger and long-term RCTs may further confirm this promising outcomes of Resmetirom use in MASLD.

Assessment of the Liver Steatosis and Fibrosis Risk in Metabolic Syndrome and Its Individual Components, Considering the Varying Definitions Used in Clinical Practice throughout Time: A Retrospective Cross-Sectional Study

Multiple modifications of metabolic syndrome diagnostic criteria have been made-NCEP: ATP III (from 2001, modified in 2004), IDF (2005), IDF Consortium (2009), or Polish Scientific Society Consortium standards (2022) are now frequently in use. Hepatosteatosis and hepatofibrosis are commonly mentioned aspects of metabolic syndrome that greatly increase the likelihood of developing complications. The objective of the study was to assess different diagnostic criteria for metabolic syndrome based on the prevalence of liver steatosis and fibrosis. A retrospective analysis was conducted on the medical data of 2102 patients. Out of all the single criteria, meeting the obesity criterion based on waist circumference showed the highest increase in the risk of hepatosteatosis (by 64-69%, depending on the definition used)-hypertriglyceridemia increased the risk of hepatofibrosis by 71%. Regardless of the specific criteria used, patients with metabolic syndrome had a 34-36% increased likelihood of developing hepatosteatosis-the probability of hepatofibrosis varied between 42% and 47% for the criteria established in 2004, 2005, and 2009, while the Polish 2022 criteria were not statistically significant (p = 0.818). It seems appropriate to establish consistent metabolic syndrome diagnostic criteria-the 2009 IDF guidelines are the most effective in assessing hepatosteatosis and fibrosis risk.

Gut microbiota causally affects drug-induced liver injury via plasma metabolites: a Mendelian randomization study

Background

The gut microbiota and plasma metabolites play important roles in the progression of drug-induced liver injury (DILI). We investigated the causal associations between the gut microbiota, plasma metabolome, and DILI.

Methods

The summary data for gut microbiota (n = 18,340), plasma metabolome (n = 8,299), and DILI (n = 366,838) were obtained from the large genome-wide association studies. A two-sample Mendelian randomization was performed to explore the associations between the gut microbiota, plasma metabolome, and DILI. Additionally, a two-step Mendelian randomization was performed to explore the potential metabolites.

Results

Five taxa were causally associated with DILI, including Oscillospira [odds ratio (OR) = 2.257, 95% confidence interval (CI) = 1.110-4.590], Blautia (OR = 2.311, 95% CI = 1.010-5.288), Roseburia (OR = 2.869, 95% CI = 1.429-5.761), Fusicatenibacter (OR = 1.995, 95% CI = 1.024-3.890), and Prevotella 7 (OR = 1.549, 95% CI = 1.065-2.253). Moreover, 53 metabolites were causally associated with DILI. After mediation analysis, four taxa were found to affect DILI through five mediation metabolites. N6-carbamoylthreonyladenosine mediated the effect of Blautia on DILI. Acetylcarnitine mediated the effect of Fusicatenibacter on DILI. In addition, 4-cholesten-3-one mediated the effect of Prevotella 7 on DILI. Furthermore, 5,6-dihydrothymine levels and the salicylate-to-citrate ratio mediated the effect of Oscillospira on DILI.

Conclusion

We found that the gut microbiota could affect DILI through plasma metabolites, which could serve as potential biomarkers for risk stratification and elucidate underlying mechanisms for further investigation of DILI.

Disinfection Byproducts of Haloacetaldehydes Disrupt Hepatic Lipid Metabolism and Induce Lipotoxicity in High-Fat Culture Conditions

Unhealthy lifestyles, obesity, and environmental pollutants are strongly correlated with the development of nonalcoholic fatty liver disease (NAFLD). Haloacetaldehyde-associated disinfection byproducts (HAL-DBPs) at various multiples of concentrations found in finished drinking water together with high-fat (HF) were examined to gauge their mixed effects on hepatic lipid metabolism. Using new alternative methods (NAMs), studying effects in human cells in vitro for risk assessment, we investigated the combined effects of HF and HAL-DBPs on hepatic lipid metabolism and lipotoxicity in immortalized LO-2 human hepatocytes. Coexposure of HAL-DBPs at various multiples of environmental exposure levels with HF increased the levels of triglycerides, interfered with de novo lipogenesis, enhanced fatty acid oxidation, and inhibited the secretion of very low-density lipoproteins. Lipid accumulation caused by the coexposure of HAL-DBPs and HF also resulted in more severe lipotoxicity in these cells. Our results using an in vitro NAM-based method provide novel insights into metabolic reprogramming in hepatocytes due to coexposure of HF and HAL-DBPs and strongly suggest that the risk of NAFLD in sensitive populations due to HAL-DBPs and poor lifestyle deserves further investigation both with laboratory and epidemiological tools. We also discuss how results from our studies could be used in health risk assessments for HAL-DBPs.

Mapping the global research landscape on nonalcoholic fatty liver disease and insulin resistance: A visualization and bibliometric study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a liver condition that is prevalent worldwide and associated with significant health risks and economic burdens. As it has been linked to insulin resistance (IR), this study aimed to perform a bibliometric analysis and visually represent the scientific literature on IR and NAFLD.

AIM

To map the research landscape to underscore critical areas of focus, influential studies, and future directions of NAFLD and IR.

METHODS

This study conducted a bibliometric analysis of the literature on IR and NAFLD indexed in the SciVerse Scopus database from 1999 to 2022. The search strategy used terms from the literature and medical subject headings, focusing on terms related to IR and NAFLD. VOSviewer software was used to visualize research trends, collaborations, and key thematic areas. The analysis examined publication type, annual research output, contributing countries and institutions, funding agencies, journal impact factors, citation patterns, and highly cited references.

RESULTS

This analysis identified 23124 documents on NAFLD, revealing a significant increase in the number of publications between 1999 and 2022. The search retrieved 715 papers on IR and NAFLD, including 573 (80.14%) articles and 88 (12.31%) reviews. The most productive countries were China (n = 134; 18.74%), the United States (n = 122; 17.06%), Italy (n = 97; 13.57%), and Japan (n = 41; 5.73%). The leading institutions included the Università degli Studi di Torino, Italy (n = 29; 4.06%), and the Consiglio Nazionale delle Ricerche, Italy (n = 19; 2.66%). The top funding agencies were the National Institute of Diabetes and Digestive and Kidney Diseases in the United States (n = 48; 6.71%), and the National Natural Science Foundation of China (n = 37; 5.17%). The most active journals in this field were Hepatology (27 publications), the Journal of Hepatology (17 publications), and the Journal of Clinical Endocrinology and Metabolism (13 publications). The main research hotspots were "therapeutic approaches for IR and NAFLD" and "inflammatory and high-fat diet impacts on NAFLD".

CONCLUSION

This is the first bibliometric analysis to examine the relationship between IR and NAFLD. In response to the escalating global health challenge of NAFLD, this research highlights an urgent need for a better understanding of this condition and for the development of intervention strategies. Policymakers need to prioritize and address the increasing prevalence of NAFLD.

Oligonucleotide therapies for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) represents a severe disease subtype of nonalcoholic fatty liver disease (NAFLD) that is thought to be highly associated with systemic metabolic abnormalities. It is characterized by a series of substantial liver damage, including hepatocellular steatosis, inflammation, and fibrosis. The end stage of NASH, in some cases, may result in cirrhosis and hepatocellular carcinoma (HCC). Nowadays a large number of investigations are actively under way to test various therapeutic strategies, including emerging oligonucleotide drugs (e.g., antisense oligonucleotide, small interfering RNA, microRNA, mimic/inhibitor RNA, and small activating RNA) that have shown high potential in treating this fatal liver disease. This article systematically reviews the pathogenesis of NASH/NAFLD, the promising druggable targets proven by current studies in chemical compounds or biological drug development, and the feasibility and limitations of oligonucleotide-based therapeutic approaches under clinical or pre-clinical studies.

The role of glucagon-like peptide-1 receptor agonists in metabolic dysfunction-associated steatohepatitis

Despite its considerable and growing burden, there are currently no Food and Drug Administration-approved treatments for metabolic dysfunction-associated steatotic liver disease or its progressive form, metabolic dysfunction-associated steatohepatitis (MASH). Several glucagon-like peptide-1 receptor agonists (GLP-1RAs) and other agents are in various phases of clinical development for use in MASH; an ideal therapy should reduce liver fat content, improve chronic liver disease, help mitigate metabolic comorbidities and decrease all-cause mortality. Because of interconnected disease mechanisms, metabolic dysfunction-associated steatotic liver disease/MASH often coexists with type 2 diabetes (T2D), obesity and cardiovascular disease. Various GLP-1RAs are Food and Drug Administration-approved for use in T2D, and two, liraglutide and semaglutide, are approved for overweight and obesity. GLP-1RAs decrease glucose levels and body weight and improve cardiovascular outcomes in people with T2D who are at high risk of cardiovascular disease. In addition, GLP-1RAs have been reported to reduce liver fat content and liver enzymes, reduce oxidative stress and improve hepatic de novo lipogenesis and the histopathology of MASH. Weight loss may contribute to these effects; however, the exact mechanisms are unknown. Adverse events that are commonly associated with GLP-1RAs include vomiting, nausea and diarrhoea. There is a lack of evidence from meta-analyses regarding the increased risk of acute pancreatitis and various forms of cancer with GLP-1RAs. Large-scale, phase 3 trials, which will provide definitive data on GLP-1RAs and other potential therapies in MASH, are ongoing. Given the spectrum of modalities under investigation, it is hoped that these trials will support the identification of pharmacotherapies that provide clinical benefit for patients with MASH.

Metabolic Dysfunction-Associated Steatotic Liver Disease: From Pathogenesis to Current Therapeutic Options

The epidemiological burden of liver steatosis associated with metabolic diseases is continuously growing worldwide and in all age classes. This condition generates possible progression of liver damage (i.e., inflammation, fibrosis, cirrhosis, hepatocellular carcinoma) but also independently increases the risk of cardio-metabolic diseases and cancer. In recent years, the terminological evolution from "nonalcoholic fatty liver disease" (NAFLD) to "metabolic dysfunction-associated fatty liver disease" (MAFLD) and, finally, "metabolic dysfunction-associated steatotic liver disease" (MASLD) has been paralleled by increased knowledge of mechanisms linking local (i.e., hepatic) and systemic pathogenic pathways. As a consequence, the need for an appropriate classification of individual phenotypes has been oriented to the investigation of innovative therapeutic tools. Besides the well-known role for lifestyle change, a number of pharmacological approaches have been explored, ranging from antidiabetic drugs to agonists acting on the gut-liver axis and at a systemic level (mainly farnesoid X receptor (FXR) agonists, PPAR agonists, thyroid hormone receptor agonists), anti-fibrotic and anti-inflammatory agents. The intrinsically complex pathophysiological history of MASLD makes the selection of a single effective treatment a major challenge, so far. In this evolving scenario, the cooperation between different stakeholders (including subjects at risk, health professionals, and pharmaceutical industries) could significantly improve the management of disease and the implementation of primary and secondary prevention measures. The high healthcare burden associated with MASLD makes the search for new, effective, and safe drugs a major pressing need, together with an accurate characterization of individual phenotypes. Recent and promising advances indicate that we may soon enter the era of precise and personalized therapy for MASLD/MASH.

Proteomic and metabolomic analysis of GH deficiency-induced NAFLD in hypopituitarism: insights into oxidative stress

Objective

Individuals with hypopituitarism (HPs) have an increased risk of developing non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) due to growth hormone deficiency (GHD). We aimed to investigate the possible mechanisms underlying the relationship between GHD and NAFLD using proteomic and metabolomic insights.

Methods

Serum metabolic alternations were assessed in male HPs using untargeted metabolomics. A rat model of HP was established through hypophysectomy, followed by recombinant human growth hormone (rhGH) intervention. The mechanisms underlying GHD-mediated NAFLD were elucidated through the application of label-free proteomics and phosphorylation proteomics.

Results

Metabolomic analysis revealed that biomarkers of mitochondrial dysfunction and oxidative stress, such as alanine, lactate, and creatine, were significantly elevated in HPs compared to age-matched controls. In rats, hypophysectomy led to marked hepatic steatosis, lipid peroxidation, and reduced glutathione (GSH), which were subsequently modulated by rhGH replacement. Proteomic analysis identified cytochrome P450s, mitochondrial translation elongation, and PPARA activating genes as the major distinguishing pathways in hypophysectomized rats. The processes of fatty acid transport, synthesis, oxidation, and NADP metabolism were tightly described. An enhanced regulation of peroxisome β-oxidation and ω-oxidation, together with a decreased NADPH regeneration, may exacerbate oxidative stress. Phosphoproteome data showed downregulation of JAK2-STAT5B and upregulation of mTOR signaling pathway.

Conclusions

This study identified proteo-metabolomic signatures associated with the development of NAFLD in pituitary GHD. Evidence was found of oxidative stress imbalance resulting from abnormal fatty acid oxidation and NADPH regeneration, highlighting the role of GH deficiency in the development of NAFLD.

Hepatic selective insulin resistance at the intersection of insulin signaling and metabolic dysfunction-associated steatotic liver disease

Insulin resistance (IR) is a major pathogenic factor in the progression of MASLD. In the liver, insulin suppresses gluconeogenesis and enhances de novo lipogenesis (DNL). During IR, there is a defect in insulin-mediated suppression of gluconeogenesis, but an unrestrained increase in hepatic lipogenesis persists. The mechanism of increased hepatic steatosis in IR is unclear and remains controversial. The key discrepancy is whether insulin retains its ability to directly regulate hepatic lipogenesis. Blocking insulin/IRS/AKT signaling reduces liver lipid deposition in IR, suggesting insulin can still regulate lipid metabolism; hepatic glucose metabolism that bypasses insulin's action may contribute to lipogenesis; and due to peripheral IR, other tissues are likely to impact liver lipid deposition. We here review the current understanding of insulin's action in governing different aspects of hepatic lipid metabolism under normal and IR states, with the purpose of highlighting the essential issues that remain unsettled.

Metabolic-associated fatty liver disease is characterized by a post-oral glucose load hyperinsulinemia in individuals with mild metabolic alterations

Metabolic-associated fatty liver disease (MAFLD) has been identified as risk factor of incident type 2 diabetes (T2D), but the underlying postprandial mechanisms remain unclear. We compared the glucose metabolism, insulin resistance, insulin secretion, and insulin clearance post-oral glucose tolerance test (OGTT) between individuals with and without MAFLD. We included 50 individuals with a body mass index (BMI) between 25 and 40 kg/m2 and ≥1 metabolic alteration: increased fasting triglycerides or insulin, plasma glucose 5.5-6.9 mmol/L, or glycated hemoglobin 5.7-5.9%. Participants were grouped according to MAFLD status, defined as hepatic fat fraction (HFF) ≥5% on MRI. We used oral minimal model on a frequently sampled 3 h 75 g-OGTT to estimate insulin sensitivity, insulin secretion, and pancreatic β-cell function. Fifty percent of participants had MAFLD. Median age (IQR) [57 (45-65) vs. 57 (44-63) yr] and sex (60% vs. 56% female) were comparable between groups. Post-OGTT glucose concentrations did not differ between groups, whereas post-OGTT insulin concentrations were higher in the MAFLD group (P < 0.03). Individuals with MAFLD exhibited lower insulin clearance, insulin sensitivity, and first-phase pancreatic β-cell function. In all individuals, increased insulin incremental area under the curve and decreased insulin clearance were associated with HFF after adjusting for age, sex, and BMI (P < 0.02). Among individuals with metabolic alterations, the presence of MAFLD was characterized mainly by post-OGTT hyperinsulinemia and reduced insulin clearance while exhibiting lower first phase β-cell function and insulin sensitivity. This suggests that MAFLD is linked with impaired insulin metabolism that may precede T2D.NEW & NOTEWORTHY Using an oral glucose tolerance test, we found hyperinsulinemia, lower insulin sensitivity, lower insulin clearance, and lower first-phase pancreatic β-cell function in individuals with MAFLD. This may explain part of the increased risk of incident type 2 diabetes in this population. These data also highlight implications of hyperinsulinemia and impaired insulin clearance in the progression of MAFLD to type 2 diabetes.

Influence of quitting smoking on diabetes-related complications: A scoping review with a systematic search strategy

INTRODUCTION

Smoking in people with diabetes markedly elevates their risk of developing complications and increases the likelihood of cardiovascular mortality. This review is the first to specifically provide evidence-based analysis about the influence of quitting smoking on diabetes-related complications in people with type 2 diabetes.

METHOD

The present review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. All human clinical studies assessing the effects of stopping smoking cessation on diabetes-related complications were included. PubMed and Embase were screened until January 2024. References of primary studies and principal peer-reviewed scientific journals in the field were manually screened.

RESULTS

We identified a total of 1023 studies. Only 26 met the criteria for eligibility. In general quitting smoking is associated with decreased risks of myocardial infarction and ischemic stroke. Regarding microvascular complications, the strongest evidence for the beneficial effects of smoking cessation is observed in diabetic nephropathy. However, the relationship between smoking cessation and retinopathy, neuropathy, diabetic foot complications and diabetic-related erectile dysfunction, is poorly investigated.

CONCLUSION

Quitting smoking offers significant advantages in managing diabetes-related complications, significantly lowering the risks of myocardial infarction, ischemic stroke, and diabetic nephropathy. This underscores the importance of cessation. Providing evidence-based information on the benefits of stopping smoking for people with type 2 diabetes who smoke, can bolster smoking cessation efforts in the context of diabetes management.

Anthocyanins: Potential phytochemical candidates for the amelioration of non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is described by too much hepatic fat deposition causing steatosis, which further develops into nonalcoholic steatohepatitis (NASH), defined by necroinflammation and fibrosis, progressing further to hepatic cirrhosis, hepatocellular carcinoma, and liver failure. NAFLD is linked to different aspects of the metabolic syndrome like obesity, insulin resistance, hypertension, and dyslipidemia, and its pathogenesis involves several elements including diet, obesity, disruption of lipid homeostasis, and a high buildup of triglycerides and other lipids in liver cells. It is therefore linked to an increase in the susceptibility to developing diabetes mellitus and cardiovascular diseases. Several interventions exist regarding its management, but the availability of natural sources through diet will be a benefit in dealing with the disorder due to the immensely growing dependence of the population worldwide on natural sources owing to their ability to treat the root cause of the disease. Anthocyanins (ACNs) are naturally occurring polyphenolic pigments that exist in the form of glycosides, which are the glucosides of anthocyanidins and are produced from flavonoids via the phenyl propanoid pathway. To understand their mode of action in NAFLD and their therapeutic potential, the literature on in vitro, in vivo, and clinical trials on naturally occurring ACN-rich sources was exhaustively reviewed. It was concluded that ACNs show their potential in the treatment of NAFLD through their antioxidant properties and their efficacy to control lipid metabolism, glucose homeostasis, transcription factors, and inflammation. This led to the conclusion that ACNs possess efficacy in the amelioration of NAFLD and the various features associated with it. However, additional clinical trials are required to justify the potential of ACNs in NAFLD.