Effects of Dietary Fructose Restriction on Liver Fat, De Novo Lipogenesis, and Insulin Kinetics in Children With Obesity

The Hepatic Axis Fructose-Methylglyoxal-AMPK: Starring or Secondary Role in Chronic Metabolic Disease?

Biochemical alterations linked to metabolic syndrome (MetS), type 2 diabetes (T2DM), and metabolic dysfunction-associated steatotic liver disease (MASLD) may be brought on by the Western diet. Based on research conducted over the past decade, fructose is one of the main culprits. Over 80% of ingested fructose is metabolized by the liver at first pass, where it stimulates de novo lipogenesis (DNL) to drive hepatic triglyceride (TG) synthesis, which contributes to MASLD, hepatic insulin resistance (IR), and dyslipidemia. Fructose reduction produces quick and significant amelioration in these metabolic disturbances. We hereby propose potential overarching processes that can link these pathways to signaling disruption by the critical metabolic sensor AMP-activated protein kinase (AMPK). We proffer that when large amounts of fructose and glucose enter the liver, triose fluxes may be sufficient to produce transient increases in methylglyoxal (MG), allowing steady-state concentrations between its production and catabolism by glyoxalases to be high enough to modify AMPK-sensitive functional amino acid residues. These reactions would transiently interfere with AMPK activation by both AMP and aldolase. Such a sequence of events would boost the well-documented lipogenic impact of fructose. Given that MG adducts are irreversible, modified AMPK molecules would be less effective in metabolite sensing until they were replaced by synthesis. If proven, this mechanism provides another avenue of possibilities to tackle the problem of fructose in our diet. We additionally discuss potential multimodal treatments and future research avenues for this apparent hepatic AMPK malfunction.

Exploring Glyoxalase Strategies for Managing Sugar-Induced Chronic Diseases

The liver's crucial role in methylglyoxal (MG) metabolism is frequently overlooked in the literature. We present a perspective that enhances the current understanding of the role of methylglyoxal (MG) and the glyoxalase cycle in the pathogenesis of insulin resistance and obesity, ultimately leading to type 2 diabetes mellitus (DM) and cardiovascular disease (CVD). Fructose may be a significant substrate contributing, particularly in contemporary times, to the flux of trioses in the liver, accounting for a substantial portion of MG production. The steady-state concentration of MG-and the subsequent modification of proteins-would then be determined by the flux of trioses, their utilization in lipogenesis, and their decomposition into MG, which is further converted into D-lactate by glyoxalase enzymes GLO1 and GLO2. Consequently, enhancing the activity and/or expression of GLO1 could potentially mitigate the adverse effects of fructose in the liver. Additional research and validation are required to confirm these biological pathways. These arguments are in favor of further research into safe and efficient ways to activate the glyoxalase pathway to lessen the negative effects of fructose metabolism that lead to insulin resistance (IR) and its related repercussions.

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.

ACG Clinical Guideline: Malnutrition and Nutritional Recommendations in Liver Disease

Malnutrition, defined as deficiency, excess, or imbalance of nutrients, is a common complication in patients with liver disease, especially those with cirrhosis. Malnutrition may present as an isolated micronutrient deficiency, such as zinc deficiency, and it commonly presents as frailty and/or sarcopenia in patients with advanced liver disease. Patients with cirrhosis and/or alcohol-associated hepatitis should be assessed for malnutrition because it adversely affects patient outcomes including mortality, as well as waitlist and posttransplant outcomes among liver transplant candidates. The prevalence of malnutrition varies based on the method of assessment and disease severity, being higher in those with advanced liver disease. Among stable outpatients with cirrhosis, counseling should be done to eat small frequent meals, a night-time snack between 7 PM and 10 PM, and 2 or more cups of coffee daily. In selected patients with metabolic dysfunction-associated steatohepatitis, vitamin E 800 IU/d should be provided. Among hospitalized patients with cirrhosis, nutritional supplementation preferably by enteral route should be implemented in those with poor oral intake of daily requirements of proteins and/or calories. Protein intake should not be restricted including patients with decompensated cirrhosis and hepatic encephalopathy. A vegetable source of protein seems to be better tolerated than an animal source of protein in patients with hepatic encephalopathy. Branched chain amino acids augment the efficacy of lactulose and rifaximin in the treatment of hepatic encephalopathy. Level of evidence and strength of recommendations were evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations system. This guideline was developed under the auspices of the American College of Gastroenterology Practice Parameters Committee.

UPLC-QqQMS based targeted metabolomics reveal combination impact on metabolism caused by bisphenol AF and fructose combined exposure in male mice

Bisphenol AF (BPAF), a fluorinated alternative to the plasticizer bisphenol A (BPA), is found in both the environment and the human body. Fructose is one of the sweeteners that has been widely used in recent years. Prior research has verified that the combined exposure to fructose and BPA considerably worsened the impact on glycolipid metabolism. However, it is currently unclear whether BPAF have a combination effect on health with fructose. Serum glucose and insulin, liver biochemistry, histology of the liver and adipose tissue, serum profiles of amino acids, vitamins, bile acids, steroid hormones, catecholamines, and adipocytokines like leptin, omentin-1, adiponectin, asprosin, and adipocyte fatty acid binding protein (A-FABP) of male mice were all investigated in this study following a week of combined exposure to two doses of BPAF (lower dose: 0.25, and higher dose: 25 μg/kg daily). The results showed that simultaneous exposure to lower doses of BPAF and fructose considerably increased blood insulin and liver coefficient, total bilirubin, direct bilirubin, and glucose while significantly decreasing body weight, food intake, liver creatinine, and serum leptin, asprosin, and A-FABP. According to histology analysis, adipocyte enlargement may result from lower dose BPAF and fructose combined exposure, while bile duct dilatation may result from both lower and higher doses of BPAF combined with fructose. Concurrently, the combination of lower doses of BPAF and fructose increased the release of adrenocortical hormones and catecholamines, worsened metabolic disorders in amino acids such as histidine, arginine and proline, branched chain amino acid (isoleucine), and aromatic amino acids (tryptophan and phenylalanine), and aggravated the depletion of vitamin B12 and A. Interestingly, following the combined exposure to BPAF and fructose, bile acids including taurocholic acid, deoxycholic acid, cholic acid, and taurine ursodeoxycholic acid rose in a dose-dependent manner. According to these results, exposure to fructose and BPAF together may have a more detrimental effect on metabolism than either substance alone. Further research should be conducted to verify the impact of joint exposure to BPAF and fructose on human.

Consensus on the key characteristics of metabolism disruptors

Metabolism-disrupting agents (MDAs) are chemical, infectious or physical agents that increase the risk of metabolic disorders. Examples include pharmaceuticals, such as antidepressants, and environmental agents, such as bisphenol A. Various types of studies can provide evidence to identify MDAs, yet a systematic method is needed to integrate these data to help to identify such hazards. Inspired by work to improve hazard identification of carcinogens using key characteristics (KCs), we developed 12 KCs of MDAs based on our knowledge of processes underlying metabolic diseases and the effects of their causal agents: (1) alters function of the endocrine pancreas; (2) impairs function of adipose tissue; (3) alters nervous system control of metabolic function; (4) promotes insulin resistance; (5) disrupts metabolic signalling pathways; (6) alters development and fate of metabolic cell types; (7) alters energy homeostasis; (8) causes inappropriate nutrient handling and partitioning; (9) promotes chronic inflammation and immune dysregulation in metabolic tissues; (10) disrupts gastrointestinal tract function; (11) induces cellular stress pathways; and (12) disrupts circadian rhythms. In this Consensus Statement, we present the logic that revealed the KCs of MDAs and highlight evidence that supports the identification of KCs. We use chemical, infectious and physical agents as examples to illustrate how the KCs can be used to organize and use mechanistic data to help to identify MDAs.

Mannose reduces fructose metabolism and reverses MASH in human liver slices and murine models in vivo

BACKGROUND

Fibrosis drives liver-related mortality in metabolic dysfunction-associated steatohepatitis (MASH), yet we have limited medical therapies to target MASH-fibrosis progression. Here we report that mannose, a simple sugar, attenuates MASH steatosis and fibrosis in 2 robust murine models and human liver slices.

METHODS

The well-validated fat-and-tumor MASH murine model for liver steatosis and fibrosis was employed. Mannose was supplied in the drinking water at the start ("Prevention" group) or at week 6 of the 12-week MASH regimen ("Therapy" group). The in vivo antifibrotic effects of mannose supplementation were tested in a second model of carbon tetrachloride (CCl4)-induced liver fibrosis. A quantitative and automated digital pathology approach was used to comprehensively assess steatosis and fibrosis phenotypes. Mannose was also tested in vitro in human and primary mouse hepatocytes conditioned with free fatty acids alone or with fructose, and human precision-cut liver slices from patients with end-stage MASH cirrhosis.

RESULTS

Oral mannose supplementation improved liver fibrosis in vivo in both fat-and-tumor MASH and CCl4 mouse models, as well as in human precision-cut liver slice MASH samples. Mannose also reduced liver steatosis in fat-and-tumor MASH mice, and in human and mouse hepatocytes in vitro. Ketohexokinase, the main enzyme in fructolysis, was decreased with mannose in whole mouse liver, cultured hepatocytes, and human precision-cut liver slices. Removal of fructose or overexpression of ketohexokinase each abrogated the antisteatotic effects of mannose.

CONCLUSIONS

This study identifies mannose as a novel therapeutic candidate for MASH that mitigates steatosis by dampening hepatocyte ketohexokinase expression and exerts independent antifibrotic effects in 2 mouse models and human liver tissue slices.

Early childhood adiposity, lifestyle and gut microbiome are linked to steatotic liver disease development in adolescents

BACKGROUND/OBJECTIVES

To examine the relationship between early childhood adiposity, adolescent lifestyles, gut microbiota and steatotic liver disease (SLD) development in adolescents using data from a prospective, longitudinal cohort study.

METHODS

We included 69 adolescents (14-17 years old) with SLD and 69 adolescents without SLD, matched for BMI-z scores, sex, and age, from the 13-year longitudinal cohort the "Growth and Obesity Cohort Study". Anthropometric data between the ages of 4 and 17 and lifestyle parameters (including diet and physical activity) at 14-17 years old were evaluated. Fecal samples were collected and microbiome composition and function were assessed using 16S ribosomal RNA amplicon sequencing.

RESULTS

Principal component analysis demonstrated dietary intake factors and childhood adiposity factors expanding the distribution variation between case and control groups, respectively. Lower odds of developing SLD during adolescence was associated with higher levels of daily fiber intake during adolescence (adjusted odds ratio = 0.91) and lower childhood adiposity (triceps skinfold at 5 years of age, suprailiac skinfold at 8 and 11 years of age, and waist-to-hip ratio at age 5-9 years). SLD was associated with a lower abundance of specific microbial species, such as Bacteroides vulgatus, which was higher in the control group compared to the case group (control/case abundance ratio = 18.71). B. vulgatus abundance also positively correlated with dietary fiber intake and inversely correlated with childhood adiposity.

CONCLUSIONS

Adiposity in early childhood and a low dietary fiber intake may contribute to the pathogenesis of SLD during adolescence, possibly through alterations to the intestinal microbiome; these findings could inform early disease markers and targets for intervention.

Modifiable cardiovascular risk factors in children at risk of acute myocardial infarction: A comprehensive review

While acute myocardial infarction is rare in children, a part of the pediatric population is at a higher risk due to preexisting non-modifiable conditions. To mitigate the risk, modifiable risk factors such as unhealthy diet or sedentary lifestyle should be controlled from childhood, promoting healthy habits from the earliest stages. The primary purpose of this review is to assess the evidence on lifestyle/nutrition related modifiable risk factor intervention on the risk of acute myocardial infarction in children found in four databases, PubMed, Embase, Scopus and WoS. After screening, 29 of 272 articles assessed met the inclusion criteria. We found evidence that a healthy lifestyle, including an adequate dietary pattern and good eating habits in childhood, reduces the prevalence of acute myocardial infarction. The data retrieved from this review are consistent with the hypothesis that a healthy lifestyle might contribute lower the risk of acute myocardial infarction in at-risk children.

Perinatal obesity primes the hepatic metabolic stress response in the offspring across life span

Perinatal obesity is associated with an increased risk of metabolic diseases and hepatic dysfunction in offspring. However, the underlying mechanisms of this metabolic programming remain incompletely understood. This study aimed to elucidate the influence of maternal obesity and early life exposure to high-fat diet on offspring liver phenotype, hepatokine profile, and key components of hepatic metabolism. To this end, we employed a murine high-fat diet-induced perinatal obesity model, investigating the offspring in early life and late adulthood. After exposure to perinatal obesity, the offspring showed a significantly increased body weight in early life with no histological signs of steatosis, but a dysregulated hepatokine profile. Proteomic profiling, followed by molecular analyses, revealed a decreased lipogenesis and increased fatty acid oxidation, suggesting a protective mechanism against the development of steatosis. These changes were accompanied by increased markers of lipid peroxidation and DNA damage, indicating increased oxidative stress. Concomitantly, the antioxidative enzymes catalase and superoxide dismutase 2 were significantly reduced and oxidative phosphorylation was impaired, implying an altered oxidative stress response. While changes in oxidative stress level were only detected in early life, the lipid metabolism was altered across life span. This metabolic programming could determine the resilience and susceptibility to chronic liver disease later in life.

Impact of Weight Loss on Metabolic Dysfunction Associated Steatohepatitis and Hepatic Fibrosis

PURPOSE OF REVIEW

This review highlights the impact of weight loss on metabolic dysfunction associated steatotic liver disease (MASLD), formally known as nonalcoholic fatty liver disease (NAFLD), and its progressive form of metabolic dysfunction associated steatohepatitis (MASH), formally known as nonalcoholic steatohepatitis (NASH). The effects of weight loss, as achieved through lifestyle modification, pharmacotherapy, bariatric surgery or endobariatric procedures on MASLD/MASH and hepatic fibrosis are discussed.

RECENT FINDINGS

Although foundational in the treatment of MASLD/MASH, weight loss through life-style modification is challenging for most patients to achieve and sustain long-term. In patients with MASLD/MASH, a multidisciplinary approach may facilitate success with lifestyle modification, individualized consideration of pharmacotherapies and/or surgical approaches that have potential to lend an improvement in MASLD/MASH. Effective and sustained weight loss improves hepatic steatosis, steatohepatitis and potentially hepatic fibrosis. Improvement in hepatic fibrosis can improve patient-related outcomes associated with complications of advanced hepatic fibrosis or cirrhosis in patients with MASLD/MASH. Identifying risk factors that influence MASLD/MASH and early implementation of therapeutic weight loss strategies may improve chronic liver injury and decrease risk for adverse clinical outcomes related to progressive hepatic fibrosis attributable to MASLD/MASH.

Examining Prenylated Xanthones as Potential Inhibitors Against Ketohexokinase C Isoform for the Treatment of Fructose-Driven Metabolic Disorders: An Integrated Computational Approach

Background/Objectives: Fructose-driven metabolic disorders, such as obesity, non-alcoholic fatty liver disease (NAFLD), dyslipidemia, and type 2 diabetes, are significant global health challenges. Ketohexokinase C (KHK-C), a key enzyme in fructose metabolism, is a promising therapeutic target. α-Mangostin, a naturally occurring prenylated xanthone, has been identified as an effective KHK-C inhibitor, prompting exploration of its analogs for enhanced efficacy. This study aimed to identify α-Mangostin analogs with improved inhibitory properties against KHK-C to address these disorders. Methods: A library of 1383 analogs was compiled from chemical databases and the literature. Molecular docking, binding free energy calculations, pharmacokinetic assessments, molecular dynamics simulations, and quantum mechani-cal analyses were used to screen and evaluate the compounds. α-Mangostin's binding affinity (37.34 kcal/mol) served as the benchmark. Results: Sixteen analogs demonstrated binding affinities superior to α-Mangostin (from -45.51 to -61.3 kcal/mol), LY-3522348 (-45.36 kcal/mol), and reported marine-derived inhibitors (from -22.74 to -51.83 kcal/mol). Hits 7, 8, 9, 13, and 15 not only surpassed these benchmarks in binding affinity, but also exhibited superior pharmacokinetic properties compared to α-Mangostin, LY-3522348, and marine-derived inhibitors, indicating strong in vivo potential. Among these, hit 8 emerged as the best performer, achieving a binding free energy of -61.30 kcal/mol, 100% predicted oral absorption, enhanced metabolic stability, and stable molecular dynamics. Conclusions: Hit 8 emerged as the most promising candidate due to its superior binding affinity, favorable pharmacokinetics, and stable interactions with KHK-C. These findings highlight its potential for treating fructose-driven metabolic disorders, warranting further experimental validation.

Nicotinamide Adenine Dinucleotide Phosphate Oxidases and Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by lipid accumulation in the liver due to an excess in their supplies or an impairment in their management. While some patients remain stable for years, a proportion of them progress up to steatohepatitis (MASH). MASLD links with systemic pathways being associated with metabolic and non-metabolic diseases. Although liver lipid accumulation represents the first hit for MASLD, the pathophysiology of its development and progression to MASH remains not completely understood. Oxidative stress has received particular attention in recent years, as most of the oxidative process occurs in the liver, which is also the target of oxidative stress-induced damage. Growing evidence linked the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOX) to the increased liver production of reactive oxygen species up to liver damage and fibrosis. NOX acts both in hepatocytes and in non-parenchymal hepatic cells, contributing to hepatocyte lipotoxicity, impaired hepatic microcirculation, hepatic stellate, and mesenchymal stem cells activation and proliferation. This review aims to summarize the current knowledge on the involvement of oxidative stress in the MASLD-MASH transition, focusing on the role of NOX isoforms, and to suggest targeting NOX as a therapeutic approach in MASLD.

Early exposure to a cholinergic receptor blocking agent mitigates adult obesity and protects pancreatic islet function in male rats

We tested the hypothesis that attenuation of the circulating insulin level in rats during early life can provide sustained protection against diet-induced obesity and metabolic dysfunction in adulthood. Male Wistar rats received intraperitoneal scopolamine butylbromide (SB) during the first 12 days of suckling, whereas control rats received 0.9% saline injections. The animals were weaned on day 21 and fed a normal chow diet. At 60 days of age, the control and SB groups were fed a normal chow diet (ND; 4.5% fat) or a high-fat diet (HF; 35% fat) until 90 days of age to induce obesity and metabolic dysfunction. Insulin secretion, food intake, and body weight were measured. Pancreatic islet function, autonomic nervous system function, and glucose homeostasis were evaluated at 90 days of age. During lactation, the plasma insulin concentration was significantly lower in the SB groups than in the control group. SB rats also exhibited reduced body weight. The HF diet resulted in obesity, glucose intolerance, insulin resistance, disruption of insulin secretion, and vagal hyperactivity in adult control rats. Remarkably, SB-treated rats fed the HF diet showed attenuated body weight and adiposity and did not develop diet-induced glucose/insulin imbalance. In addition, vagal activity and adequate pancreatic islet insulin secretion were preserved. Offspring exposed to SB during early life are provided with long-lasting protection against obesity and metabolic complications induced by an HF diet. An attenuated circulating insulin level in early life may have far-reaching consequences on metabolic programming.NEW & NOTEWORTHY High insulin levels during early life may lead to the late development of obesity and diabetes. We investigated whether attenuation of insulin levels by using an antimuscarinic agent could prevent diet-induced obesity and diabetes. Rats' early exposure to an antimuscarinic agent reduced insulin levels during the lactation period and promoted protection against obesity and metabolic dysfunctions. Independent of the programming mechanisms, insulin levels during early life may be a defining factor of health or diseases later in life.

Metabolic disorders, inter-organ crosstalk, and inflammation in the progression of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a global health concern, affecting over 30 % of adults. It is a principal driver in the development of cirrhosis and hepatocellular carcinoma. The complex pathogenesis of MASLD involves an excessive accumulation of lipids, subsequently disrupting lipid metabolism and prompting inflammation within the liver. This review synthesizes the recent research progress in understanding the mechanisms contributing to MASLD progression, with particular emphasis on metabolic disorders and interorgan crosstalk. We highlight the molecular mechanisms linked to these factors and explore their potential as novel targets for pharmacological intervention. The insights gleaned from this article have important implications for both the prevention and therapeutic management of MASLD.

Fructose-mediated AGE-RAGE axis: approaches for mild modulation

Fructose is a valuable and healthy nutrient when consumed at normal levels (≤50 g/day). However, long-term consumption of excessive fructose and elevated endogenous production can have detrimental health impacts. Fructose-initiated nonenzymatic glycation (fructation) is considered as one of the most likely mechanisms leading to the generation of reactive species and the propagation of nonenzymatic processes. In the later stages of glycation, poorly degraded advanced glycation products (AGEs) are irreversibly produced and accumulated in the organism in an age- and disease-dependent manner. Fructose, along with various glycation products-especially AGEs-are present in relatively high concentrations in our daily diet. Both endogenous and exogenous AGEs exhibit a wide range of biological effects, mechanisms of which can be associated with following: (1) AGEs are efficient sources of reactive species in vivo, and therefore can propagate nonenzymatic vicious cycles and amplify glycation; and (2) AGEs contribute to upregulation of the specific receptor for AGEs (RAGE), amplifying RAGE-mediated signaling related to inflammation, metabolic disorders, chronic diseases, and aging. Therefore, downregulation of the AGE-RAGE axis appears to be a promising approach for attenuating disease conditions associated with RAGE-mediated inflammation. Importantly, RAGE is not specific only to AGEs; it can bind multiple ligands, initiating a complex RAGE signaling network that is not fully understood. Maintaining an appropriate balance between various RAGE isoforms with different functions is also crucial. In this context, mild approaches related to lifestyle-such as diet optimization, consuming functional foods, intake of probiotics, and regular moderate physical activity-are valuable due to their beneficial effects and their ability to mildly modulate the fructose-mediated AGE-RAGE axis.

Body Composition and Progression of Biopsy-Proven Non-Alcoholic Fatty Liver Disease in Patients With Obesity

BACKGROUND

Obesity is a significant risk factor for the progression of non-alcoholic fatty liver disease (NAFLD). However, a convenient and efficacious non-invasive test for monitoring NAFLD progression in patients with obesity is currently lacking. This study aims to investigate the associations between CT-based body composition and the progression of biopsy-proven NAFLD in patients with obesity.

METHODS

Liver biopsy was conducted in patients with obesity, and the progression of NAFLD was evaluated by the NAFLD activity score (NAS). Body composition was assessed through abdominal computed tomography (CT) scans.

RESULTS

A total of 602 patients with an average age of 31.65 (±9.33) years old were included, comprising 217 male patients and 385 female patients. The wall skeletal muscle index (SMI), total SMI, and visceral fat index (VFI) were positively correlated with NAS in both male and female patients. Multivariate regression analysis demonstrated significant associations between high liver steatosis and wall SMI (HR: 1.60, 95% CI: 1.12 to 2.30), total SMI (HR: 1.50, 95% CI: 1.02 to 2.08), VSI (HR: 2.16, 95% CI: 1.48 to 3.14), visceral fat to muscle ratio (HR: 1.51, 95% CI: 1.05 to 2.18), and visceral to subcutaneous fat ratio (HR: 1.51, 95% CI: 1.07 to 2.12). Non-alcoholic steatohepatitis (NASH) was significantly associated with wall SMI (HR: 1.52, 95% CI: 1.06 to 2.19) and VSI (HR: 1.50, 95% CI: 1.03 to 2.17). Liver fibrosis ≥ F2 was significantly associated with psoas muscle index (HR: 0.64, 95% CI: 0.44 to 0.93) and psoas skeletal muscle density (HR: 0.61, 95% CI: 0.41 to 0.89).

CONCLUSIONS

Our study suggested that certain CT-based body composition indicators, notably high VFI, were significantly associated with the progression of NAFLD in patients with obesity. Great attentions and timely managements should be given to these patients with body composition characteristics associated with the risk of NAFLD progression.

Dietary Fructose: A Literature Review of Current Evidence and Implications on Metabolic Health

With the increasing intake of dietary fructose, primarily from sucrose and sweetened beverages, metabolic illnesses such as type 2 diabetes mellitus, hypertension, fatty liver disease, dyslipidemia, and hyperuricemia have become more prevalent worldwide, and there is also growing concern about the development of malignancies. These negative health impacts have been validated in various meta-analyses and randomized controlled trials. In contrast, the naturally occurring fructose found in fruits and vegetables contains only a minimal amount of fructose and, when consumed in moderation, may be a healthier choice. This review focuses on the biology of fructose, including its dietary sources, the physiology of its metabolism, and the pathological basis of various disorders related to high dietary fructose intake.

Lifestyle Interventions in Pediatric Primary Care

Pediatric clinicians should offer guidance on age-appropriate nutrition, physical activity, sleep and screen time for families of children and adolescents with obesity. They should build rapport with families, ask permission before discussing obesity-related health concerns, use preferred terminology, and recommend whole family change. Using principles of shared decision-making, pediatric clinicians and families should set individualized goals for lifestyle changes, prioritizing reducing sugar-sweetened beverage intake, increasing physical activity, and reducing screen time. Families of children and adolescents with obesity should be connected to the highest level of support accessible to and desired by the family, including intensive health behavior and lifestyle treatment programs.

Obesity, Metabolic Syndrome, and Sugar-Sweetened Beverages (SSBs) in America: A Novel Bioethical Argument for a Radical Public Health Proposal

The prevalence of obesity, metabolic syndrome, and the associated long-term chronic diseases (cardiovascular disease, type II diabetes, cancer, Alzheimer's disease, depression) have reached epidemic levels in the United States and Western nations. In response to this public health calamity, the author of this paper presents and defends a novel bioethical argument: the consistency argument for outlawing SSBs (sugar-sweetened beverages) for child consumption (the "consistency argument"). This argument's radical conclusion states that the government is justified in outlawing SSBs consumption for child consumption. The reasoning is as follows: if one accepts that the physical harm caused by chronic alcohol consumption justifies the government outlawing alcoholic beverages for child consumption, and there is strong evidence that comparable physical harms result from chronic SSBs consumption, then, mutatis mutandis, the government is also justified in outlawing child consumption of SSBs. To support this argument, the author provides extensive evidence based on epidemiological observational studies, interventional studies, controlled trials, large meta-analyses, and the pathophysiology and biological mechanisms of action behind SSBs and chronic disease. Chronic consumption of large doses of SSBs and alcoholic beverages both drive the same diseases: obesity and insulin resistance, cardiovascular disease, hypertension, and cancer. Chronic SSB consumption carries the additional risk of Alzheimer's disease, dementia, and depression. The author concludes this paper by considering prominent objections to the consistency argument, and then demonstrating that each objection is unsound.

Dietary fructose: from uric acid to a metabolic switch in pediatric metabolic dysfunction-associated steatotic liver disease

Fructose consumption in pediatric subjects is rising, as the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). Despite increasing evidence supporting the detrimental effects of fructose in the development of Metabolic Syndrome (MetS) and its related comorbidities, the association between fructose intake and liver disease remains unclear, mainly in youths. The current narrative review aims to illustrate the correlation between fructose metabolism and liver functions besides its impact on obesity and MASLD in pediatrics. Fructose metabolism is involved in the liver through the classical lipogenic pathway via de novo lipogenesis (DNL) or in the alternative pathway via uric acid accumulation. Hyperuricemia is one of the main features of MALSD patients, underlining how uric acid is growing interest as a new marker of disease. Observational and interventional studies conducted in children and adolescents, who consumed large amounts of fructose and glucose in their diet, were included. Most of these studies emphasized the association between high fructose intake and weight gain, dyslipidemia, insulin resistance, and MASLD/MASH, even in normal-weight children. Conversely, reducing fructose intake ameliorates liver fat accumulation, lipid profile, and weight. In conclusion, fructose seems a potent inducer of both insulin resistance and hepatic fat accumulation.

Associations of dietary sugars with liver stiffness in Latino adolescents with obesity differ on PNPLA3 and liver disease severity

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common paediatric liver disease. Latinos have high MASLD risk due to 50% prevalence of GG genotype of PNPLA3. Our primary aim was to evaluate associations between dietary carbohydrates/sugars and liver stiffness in Latino adolescents with obesity. Our secondary aim was to examine effect modification by (a) PNPLA3 genotype or (b) liver disease severity. Data were obtained from 114 Latino adolescents with obesity involved in two prior studies. No associations were seen between dietary carbohydrates/sugars and liver stiffness in the group as a whole. In subjects with GG genotype of PNPLA3, total sugar, fructose, sucrose, and glucose were associated with liver stiffness. Positive relationships between carbohydrate, total sugar, and sucrose and liver stiffness were stronger in those with MASLD and fibrosis compared to those with healthy livers and MASLD without fibrosis.

An international multidisciplinary consensus on pediatric metabolic dysfunction-associated fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in children and adolescents, particularly those with obesity. NAFLD is considered a hepatic manifestation of the metabolic syndrome due to its close associations with abdominal obesity, insulin resistance, and atherogenic dyslipidemia. Experts have proposed an alternative terminology, metabolic dysfunction-associated fatty liver disease (MAFLD), to better reflect its pathophysiology. This study aimed to develop consensus statements and recommendations for pediatric MAFLD through collaboration among international experts.

METHODS

A group of 65 experts from 35 countries and six continents, including pediatricians, hepatologists, and endocrinologists, participated in a consensus development process. The process encompassed various aspects of pediatric MAFLD, including epidemiology, mechanisms, screening, and management.

FINDINGS

In round 1, we received 65 surveys from 35 countries and analyzed these results, which informed us that 73.3% of respondents agreed with 20 draft statements while 23.8% agreed somewhat. The mean percentage of agreement or somewhat agreement increased to 80.85% and 15.75%, respectively, in round 2. The final statements covered a wide range of topics related to epidemiology, pathophysiology, and strategies for screening and managing pediatric MAFLD.

CONCLUSIONS

The consensus statements and recommendations developed by an international expert panel serve to optimize clinical outcomes and improve the quality of life for children and adolescents with MAFLD. These findings emphasize the need for standardized approaches in diagnosing and treating pediatric MAFLD.

FUNDING

This work was funded by the National Natural Science Foundation of China (82070588, 82370577), the National Key R&D Program of China (2023YFA1800801), National High Level Hospital Clinical Research Funding (2022-PUMCH-C-014), the Wuxi Taihu Talent Plan (DJTD202106), and the Medical Key Discipline Program of Wuxi Health Commission (ZDXK2021007).

Global perspective on nonalcoholic fatty liver disease and nonalcoholic steatohepatitis - prevalence, clinical impact, economic implications and management strategies

BACKGROUND

The metabolically-based liver disease, nonalcoholic fatty liver disease (NAFLD), is the most common cause of chronic liver disease currently affecting 38% of the world's adult population. NAFLD can be progressive leading to nonalcoholic steatohepatitis (NASH), liver transplantation, liver cancer, liver-related mortality and is associated with decreased quality of life from impaired physical functioning and increased healthcare resource utilisation. However, screening for NAFLD is cost-prohibitive but screening for high risk NAFLD (NAFLD with F2 fibrosis or greater) is imperative.

AIM

To review the global perspective on NAFLD and NASH METHODS: We retrieved articles from PubMed using search terms NAFLD, prevalence, clinical burden, economic burden and management strategies.

RESULTS

NAFLD/NASH shows geographical variation across the globe. Highest prevalence rates are in South America and the Middle East and North Africa; lowest prevalence is in Africa. NAFLD's economic impact is from direct and indirect medical costs and loss in worker productivity. It is projected that, over the next two decades, the total cost of NAFLD and diabetes will exceed $1.5 trillion (USD). Risk stratification algorithms identifying "high risk NAFLD" were made following non-invasive tests for NAFLD identification and fibrosis development. These algorithms should be used in primary care and endocrinology settings so timely and appropriate interventions (lifestyle and cardiometabolic risk factor management) can be initiated.

CONCLUSIONS

To reduce the burgeoning burden of NAFLD/NASH, management should include risk stratification algorithms for accurate identification of patients, linkage to appropriate settings, and initiation of effective treatment regimens.

The effects of inulin on solubilizing and improving anti-obesity activity of high polymerization persimmon tannin

High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.

Transcriptomic insights into the lipotoxicity of high-fat high-fructose diet in rat and mouse

Along with the increasing prevalence of obesity worldwide, the deleterious effects of high-calorie diet are gradually recognized through more and more epidemiological studies. However, the concealed and chronic causality whitewashes its unhealthy character. Given an ingenious mechanism orchestrates the metabolic adaptation to high-fat high-fructose (HFF) diet and connive its lipotoxicity, in this study, an experimental rat/mouse model of obesity was induced and a comparative transcriptomic analysis was performed to probe the mystery. Our results demonstrated that HFF diet consumption altered the transcriptomic pattern as well as different high-calorie diet fed rat/mouse manifested distinct hepatic transcriptome. Validation with RT-qPCR and Western blotting confirmed that SREBP1-FASN involved in de novo lipogenesis partly mediated metabolic self-adaption. Moreover, hepatic ACSL1-CPT1A-CPT2 pathway involved in fatty acids β-oxidation, played a key role in the metabolic adaption to HFF. Collectively, our findings enrich the knowledge of the chronic adaptation mechanisms and also shed light on future investigations. Meanwhile, our results also suggest that efforts to restore the fatty acids metabolic fate could be a promising avenue to fight against obesity and associated steatosis and insulin resistance challenged by HFF diet.

Beyond Obesity and Overweight: The Clinical Assessment and Treatment of Excess Body Fat in Children : Part 1 - Insulin Resistance as the Root Cause of Pediatric Obesity

PURPOSE OF REVIEW

Pediatric obesity and comorbidities related to insulin resistance continue to be a growing public health crisis. If lifestyle measures are unsuccessful, pharmacological and surgical interventions are offered. In this paper, we describe the driving force of the obesity crisis: hyperinsulinemia and the development of insulin resistance. We give historical background of key policy issues which have contributed to this pandemic as well as the physiologic mechanisms of insulin resistance. The prevalence of obesity will continue to rise unless the root cause of hyperinsulinemia is addressed.

RECENT FINDINGS

Current research on insulin resistance demonstrates that a decreased consumption of carbohydrates is an effective first-line dietary intervention for the treatment of obesity and related metabolic diseases. Evidence shows it is safe and beneficial. A low-carbohydrate eating pattern can be helpful to address pediatric obesity. However, there must be policy guardrails in place to ensure that this is a sustainable and viable option for children and their families. There must be a change in the nutritional environment to help individuals battle the chronic disease of obesity.

Effects of dietary sugar restriction on hepatic fat in youth with obesity

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in children. Like adults, children can develop the progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), which is characterized by hepatic inflammation, often in the presence of fibrosis. Children with NAFLD are at higher risk of liver-related complications, metabolic dysfunction, and cardiovascular disease in adulthood. Many factors contribute to the escalating prevalence of NAFLD in the pediatric population, among which are an array of dietary patterns such as overnutrition, poor diet quality, and heavy consumption of fat and sugar, including fructose. Findings from an increasing number of epidemiological studies support a connection between high habitual sugar consumption and NAFLD, especially within the context of obesity, but these studies are not able to demonstrate whether sugar is a contributing factor or instead an indicator of an overall poor diet (or lifestyle) quality. To date, only four randomized controlled dietary interventions assessing the effects of sucrose/fructose restriction on hepatic fat fraction in youth with obesity have been published. The objectives of this review are to summarize the key findings from these dietary interventions to achieve a better understanding of the strength of the relationship between dietary sugar restriction and liver fat reduction, despite their inherent limitations, and to discuss the potential impact of weight loss and fat mass reduction on improvement in hepatic steatosis.

Hepatic steatosis induced by nicotine plus Coca-Cola™ is prevented by nicotinamide riboside (NR)

Introduction

Cigarettes containing nicotine (Nic) are a risk factor for the development of cardiovascular and metabolic diseases. We reported that Nic delivered via injections or e-cigarette vapor led to hepatic steatosis in mice fed with a high-fat diet. High-fructose corn syrup (HFCS) is the main sweetener in sugar-sweetened beverages (SSBs) in the US. Increased consumption of SSBs with HFCS is associated with increased risks of non-alcoholic fatty liver disease (NAFLD). Nicotinamide riboside (NR) increases mitochondrial nicotinamide adenine dinucleotide (NAD+) and protects mice against hepatic steatosis. This study evaluated if Nic plus Coca-Cola™ (Coke) with HFCS can cause hepatic steatosis and that can be protected by NR.

Methods

C57BL/6J mice received twice daily intraperitoneal (IP) injections of Nic or saline and were given Coke (HFCS), or Coke with sugar, and NR supplementation for 10 weeks.

Results

Our results show that Nic+Coke caused increased caloric intake and induced hepatic steatosis, and the addition of NR prevented these changes. Western blot analysis showed lipogenesis markers were activated (increased cleavage of the sterol regulatory element-binding protein 1 [SREBP1c] and reduction of phospho-Acetyl-CoA Carboxylase [p-ACC]) in the Nic+Coke compared to the Sal+Water group. The hepatic detrimental effects of Nic+Coke were mediated by decreased NAD+ signaling, increased oxidative stress, and mitochondrial damage. NR reduced oxidative stress and prevented mitochondrial damage by restoring protein levels of Sirtuin1 (Sirt1) and peroxisome proliferator-activated receptor coactivator 1-alpha (PGC1) signaling.

Conclusion

We conclude that Nic+Coke has an additive effect on producing hepatic steatosis, and NR is protective. This study suggests concern for the development of NAFLD in subjects who consume nicotine and drink SSBs with HFCS.

Metabolic effects of an essential amino acid supplement in adolescents with PCOS and obesity

OBJECTIVE

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, insulin resistance, and hepatic steatosis (HS). Because dietary essential amino acid (EAA) supplementation has been shown to decrease HS in various populations, this study's objective was to determine whether supplementation would decrease HS in PCOS.

METHODS

A randomized, double-blind, crossover, placebo-controlled trial was conducted in 21 adolescents with PCOS (BMI 37.3 ± 6.5 kg/m2, age 15.6 ± 1.3 years). Liver fat, very low-density lipoprotein (VLDL) lipogenesis, and triacylglycerol (TG) metabolism were measured following each 28-day phase of placebo or EAA.

RESULTS

Compared to placebo, EAA was associated with no difference in body weight (p = 0.673). Two markers of liver health improved: HS was lower (-0.8% absolute, -7.5% relative reduction, p = 0.013), as was plasma aspartate aminotransferase (AST) (-8%, p = 0.004). Plasma TG (-9%, p = 0.015) and VLDL-TG (-21%, p = 0.031) were reduced as well. VLDL-TG palmitate derived from lipogenesis was not different between the phases, nor was insulin sensitivity (p > 0.400 for both). Surprisingly, during the EAA phase, participants reported consuming fewer carbohydrates (p = 0.038) and total sugars (p = 0.046).

CONCLUSIONS

Similar to studies in older adults, short-term EAA supplementation in adolescents resulted in significantly lower liver fat, AST, and plasma lipids and thus may prove to be an effective treatment in this population. Additional research is needed to elucidate the mechanisms for these effects.

Obesogens: a unifying theory for the global rise in obesity

Despite varied treatment, mitigation, and prevention efforts, the global prevalence and severity of obesity continue to worsen. Here we propose a combined model of obesity, a unifying paradigm that links four general models: the energy balance model (EBM), based on calories as the driver of weight gain; the carbohydrate-insulin model (CIM), based on insulin as a driver of energy storage; the oxidation-reduction model (REDOX), based on reactive oxygen species (ROS) as a driver of altered metabolic signaling; and the obesogens model (OBS), which proposes that environmental chemicals interfere with hormonal signaling leading to adiposity. We propose a combined OBS/REDOX model in which environmental chemicals (in air, food, food packaging, and household products) generate false autocrine and endocrine metabolic signals, including ROS, that subvert standard regulatory energy mechanisms, increase basal and stimulated insulin secretion, disrupt energy efficiency, and influence appetite and energy expenditure leading to weight gain. This combined model incorporates the data supporting the EBM and CIM models, thus creating one integrated model that covers significant aspects of all the mechanisms potentially contributing to the obesity pandemic. Importantly, the OBS/REDOX model provides a rationale and approach for future preventative efforts based on environmental chemical exposure reduction.

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) and Thyroid Function in Childhood Obesity: A Vicious Circle?

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a multisystem disorder characterized by the presence of fatty liver degeneration associated with excess adiposity or prediabetes/type 2 diabetes or metabolic dysregulation. An intricate relationship between the liver and thyroid has been reported in both health and disease. Simultaneously, there is a strong correlation between obesity and both MAFLD and thyroid dysfunction. In this narrative review, we highlighted the relationship between MAFLD and thyroid function in children and adolescents with obesity in order to explore how thyroid hormones (THs) act as predisposing factors in the onset, progression, and sustainability of MAFLD. THs are integral to the intricate balance of metabolic activities, ensuring energy homeostasis, and are indispensable for growth and development. Regarding liver homeostasis, THs have been suggested to interact with liver lipid homeostasis through a series of processes, including stimulating the entry of free fatty acids into the liver for esterification into triglycerides and increasing mitochondrial β-oxidation of fatty acids to impact hepatic lipid accumulation. The literature supports a correlation between MAFLD and obesity, THs and obesity, and MAFLD and THs; however, results in the pediatric population are very limited. Even though the underlying pathogenic mechanism involved in the relationship between MAFLD and thyroid function remains not fully elucidated, the role of THs as predisposing factors of MAFLD could be postulated. A potential vicious circle among these three conditions cannot be excluded. Identifying novel elements that may contribute to MAFLD could offer a practical approach to assessing children at risk of developing the condition.

Understanding the Burden of Nonalcoholic Fatty Liver Disease: Time for Action

The prevalence of nonalcoholic fatty liver disease (NAFLD) in the United States is 38%, having increased by 50% within the past 3 decades. The estimated NAFLD prevalence among people with type 2 diabetes is 55-70%. The presence of type 2 diabetes is associated with a higher likelihood of progression of NAFLD to fibrosis development, liver transplant, and death. Cardiovascular disease is the main cause of mortality among people with NAFLD, and the risk of death is significantly higher in people with both NAFLD and type 2 diabetes. NAFLD carries high patient and economic burdens but low awareness among both the general public and health care providers. This article reviews the epidemiology of NAFLD and discusses the need for appropriate risk stratification, referral for specialty care, management of cardiometabolic risk factors, and treatment of the disease. The authors present a call to action to raise awareness of NAFLD and address its increasing burden in a systematic and efficient manner.

The effect of low-fructose diet on anthropometric and metabolic factors: A systematic review and meta-analysis

AIMS

In recent decades, there has been a rise in the consumption of sugars containing fructose, raising concerns about their association with metabolic disorders and obesity. We conducted a systematic review and meta-analysis of randomized controlled trials to assess the effects of a low-fructose diet on anthropometric and metabolic variables.

DATA SYNTHESIS

We conducted a systematic review and meta-analysis of randomized controlled trials to assess the effects of low-fructose diets on anthropometric and metabolic factors. Relevant studies were identified by searching electronic databases such as PubMed, Scopus, and Web of Science up to January 2023. The quality of the included studies was assessed using the Cochrane risk-of-bias tool. Ten trials with varying intervention durations (ranging from 4 to 24 weeks) and a total of 750 participants were included. The analysis revealed that a low-fructose diet had no significant effect on weight but did have a significant impact on body mass index (SMD = -0.2; 95 % CI: -0.37, -0.04, P = 0.017) and waist circumference (SMD = -0.48; 95 % CI: -0.67, -0.29, P < 0.0001). Furthermore, a low-fructose diet significantly affected systolic blood pressure (SMD = -0.24; 95 % CI: -0.39, -0.09, P = 0.002), fasting blood glucose (SMD = -0.23; 95 % CI: -0.40, -0.07, P = 0.005), hemoglobin A1c (SMD = -0.62; 95 % CI: -0.93, -0.31, P < 0.0001), and triglyceride levels (SMD = -0.17; 95 % CI: -0.33, -0.02, P = 0.028). However, it had no significant effect on diastolic blood pressure, insulin levels, or homeostatic model assessment of insulin resistance. Subgroup analysis indicated that a low-fructose diet had a greater effect on healthy participants aged over 50 years.

CONCLUSIONS

Meta-analysis results suggest that low-fructose diets significantly reduce body mass index, waist circumference, systolic blood pressure, fasting blood glucose, hemoglobin A1c, and triglyceride levels. Additionally, the results of the current study suggest that a low-fructose diet may be more effective in healthy individuals who are older than 50 years old compared to those younger than 50 years old.

The chylomicron saga: time to focus on postprandial metabolism

Since statins have had such tremendous therapeutic success over the last three decades, the field of atherosclerosis has become somewhat LDL-centric, dismissing the relevance of triglycerides (TG), particularly chylomicrons, in atherogenesis. Nonetheless, 50% of patients who take statins are at risk of developing atherosclerotic cardiovascular disease (ASCVD) and are unable to achieve their goal LDL-C levels. This residual risk is mediated, in part by triglyceride rich lipoproteins (TRL) and their remnants. Following his seminal investigation on the subject, Zilversmit proposed that atherosclerosis is a postprandial event in 1979 (1-4). In essence, the concept suggests that remnant cholesterol-rich chylomicron (CM) and very-low density lipoprotein (VLDL) particles play a role in atherogenesis. Given the foregoing, this narrative review addresses the most recent improvements in our understanding of postprandial dyslipidemia. The primary metabolic pathways of chylomicrons are discussed, emphasizing the critical physiological role of lipoprotein lipase and apoCIII, the importance of these particles' fluxes in the postprandial period, their catabolic rate, the complexities of testing postprandial metabolism, and the role of angiopoietin-like proteins in the partition of CM during the fed cycle. The narrative is rounded out by the dysregulation of postprandial lipid metabolism in insulin resistance states and consequent CVD risk, the clinical evaluation of postprandial dyslipidemia, current research limits, and potential future study directions.

Mannose Supplementation Curbs Liver Steatosis and Fibrosis in Murine MASH by Inhibiting Fructose Metabolism

Metabolic dysfunction-associated steatohepatitis (MASH) can progress to cirrhosis and liver cancer. There are no approved medical therapies to prevent or reverse disease progression. Fructose and its metabolism in the liver play integral roles in MASH pathogenesis and progression. Here we focus on mannose, a simple sugar, which dampens hepatic stellate cell activation and mitigates alcoholic liver disease in vitro and in vivo . In the well-validated FAT-MASH murine model, oral mannose supplementation improved both liver steatosis and fibrosis at low and high doses, whether administered either at the onset of the model ("Prevention") or at week 6 of the 12-week MASH regimen ("Reversal"). The in vivo anti-fibrotic effects of mannose supplementation were validated in a second model of carbon tetrachloride-induced liver fibrosis. In vitro human and mouse primary hepatocytes revealed that the anti-steatotic effects of mannose are dependent on the presence of fructose, which attenuates expression of ketohexokinase (KHK), the main enzyme in fructolysis. KHK is decreased with mannose supplementation in vivo and in vitro, and overexpression of KHK abrogated the anti-steatotic effects of mannose. Our study identifies mannose as a simple, novel therapeutic candidate for MASH that mitigates metabolic dysregulation and exerts anti-fibrotic effects.

Effects of Consuming Beverages Sweetened with Fructose, Glucose, High-Fructose Corn Syrup, Sucrose, or Aspartame on OGTT-Derived Indices of Insulin Sensitivity in Young Adults

(1) Background: Clinical results on the effects of excess sugar consumption on insulin sensitivity are conflicting, possibly due to differences in sugar type and the insulin sensitivity index (ISI) assessed. Therefore, we compared the effects of consuming four different sugars on insulin sensitivity indices derived from oral glucose tolerance tests (OGTT). (2) Methods: Young adults consumed fructose-, glucose-, high-fructose corn syrup (HFCS)-, sucrose-, or aspartame-sweetened beverages (SB) for 2 weeks. Participants underwent OGTT before and at the end of the intervention. Fasting glucose and insulin, Homeostatic Model Assessment-Insulin Resistance (HOMA-IR), glucose and insulin area under the curve, Surrogate Hepatic Insulin Resistance Index, Matsuda ISI, Predicted M ISI, and Stumvoll Index were assessed. Outcomes were analyzed to determine: (1) effects of the five SB; (2) effects of the proportions of fructose and glucose in all SB. (3) Results: Fructose-SB and the fructose component in mixed sugars negatively affected outcomes that assess hepatic insulin sensitivity, while glucose did not. The effects of glucose-SB and the glucose component in mixed sugar on muscle insulin sensitivity were more negative than those of fructose. (4) Conclusion: the effects of consuming sugar-SB on insulin sensitivity varied depending on type of sugar and ISI index because outcomes assessing hepatic insulin sensitivity were negatively affected by fructose, and outcomes assessing muscle insulin sensitivity were more negatively affected by glucose.

The role of anti-diabetic drugs in NAFLD. Have we found the Holy Grail? A narrative review

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) has become a leading cause of liver disease, affecting 30% of the global population. NAFLD prevalence is particularly high in obese individuals and patients with type 2 diabetes mellitus (T2DM). NAFLD ranges from simple fat deposition in the liver to necroinflammation and fibrosis (non-alcoholic steatohepatitis (NASH)), NASH-cirrhosis, and/or hepatocellular carcinoma. Insulin resistance plays a key role in NAFLD pathogenesis, alongside dysregulation of adipocytes, mitochondrial dysfunction, genetic factors, and changes in gut microbiota. Since insulin resistance is also a major predisposing factor of T2DM, the administration of anti-diabetic drugs for the management of NAFLD seems reasonable.

METHODS

In this review we provide the NAFLD-associated mechanisms of action of some of the most widely used anti-diabetic drugs, namely metformin, pioglitazone, sodium-glucose transport protein-2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor analogs (GLP1 RAs), and dipeptyl-peptidase-4 inhibitors (DPP4i) and present available data regarding their use in patients with NAFLD, with and without T2DM.

RESULTS

Both metformin and DPP4i have shown rather contradictory results, while pioglitazone seems to benefit patients with NASH and is thus the only drug approved for NASH with concomitant significant liver fibrosis by all major liver societies. On the other hand, SGLT2i and GLP1 RAs seem to be beneficiary in patients with NAFLD, showing both remarkable results, with SGLT2i proving to be more efficient in the only head-to-head study so far.

CONCLUSION

In patients with NAFLD and diabetes, pioglitazone, GLP1 RAs, and SGLT2i seem to be logical treatment options. Larger studies are needed before these drugs can be recommended for non-diabetic individuals.

Differential expression of immunoregulatory cytokines in adipose tissue and liver in response to high fat and high sugar diets in female mice

A comprehensive understanding of how dietary components impact immunoregulatory gene expression in adipose tissue (AT) and liver, and their respective contributions to metabolic health in mice, remains limited. The current study aimed to investigate the metabolic consequences of a high-sucrose diet (HSD) and a high-fat diet (HFD) in female mice with a focus on differential lipid- and sucrose-induced changes in immunoregulatory gene expression in AT and liver. Female C57BL/6 J mice were fed a purified and macronutrient matched high fat, high sugar, or control diets for 12 weeks. Mice were extensively phenotyped, including glucose and insulin tolerance tests, adipose and liver gene and protein expression analysis by qPCR and Western blot, tissue lipid analyses, as well as histological analyses. Compared to the control diet, HSD- and HFD-fed mice had significantly higher body weights, with pronounced obesity along with glucose intolerance and insulin resistance only in HFD-fed mice. HSD-fed mice exhibited an intermediate phenotype, with mild metabolic deterioration at the end of the study. AT lipid composition was significantly altered by both diets, and inflammatory gene expression was only significantly induced in HFD-fed mice. In the liver however, histological analysis revealed that both HSD- and HFD-fed mice had pronounced ectopic lipid deposition indicating hepatic steatosis, but more pronounced in HSD-fed mice. This was in line with significant induction of pro-inflammatory gene expression specifically in livers of HSD-fed mice. Overall, our findings suggest that HFD consumption in female mice induces more profound inflammation in AT with pronounced deterioration of metabolic health, whereas HSD induced more pronounced hepatic steatosis and inflammation without yet affecting glucose metabolism.

Nutritional patterns as machine learning predictors of liver health in a population of elderly subjects

BACKGROUND AND AIMS

Non-alcoholic hepatic steatosis affects 25% of adults worldwide and its prevalence increases with age. There is currently no definitive treatment for NAFLD but international guidelines recommend a lifestyle-based approach, including a healthy diet. The aim of this study was to investigate the interactions between eating habits and the risk of steatosis and/or hepatic fibrosis, using a machine learning approach, in a non-institutionalized elderly population.

METHODS AND RESULTS

We recruited 1929 subjects, mean age 74 years, from the population-based Salus in Apulia Study. Dietary habits and the risk of steatosis and hepatic fibrosis were evaluated with a validated food frequency questionnaire, the Fatty Liver Index (FLI) and the FIB-4 score, respectively. Two dietary patterns associated with the risk of steatosis and hepatic fibrosis have been identified. They are both similar to a "western" diet, defined by a greater consumption of refined foods, with a rich content of sugars and saturated fats, and alcoholic and non-alcoholic calorie drinks.

CONCLUSION

This study further supports the concept of diet as a factor that significantly influences the development of the most widespread liver diseases. However, longitudinal studies are needed to better understand the causal effect of the consumption of particular foods on fat accumulation in the liver.

Lifestyle interventions in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a dynamic chronic liver disease that develops in close association with metabolic irregularities. Between 2016 and 2019, the global prevalence among adults was reported as 38% and among children and adolescents it was about 10%. NAFLD can be progressive and is associated with increased mortality from cardiovascular disease, extrahepatic cancers and liver complications. Despite these numerous adverse outcomes, no pharmacological treatments currently exist to treat nonalcoholic steatohepatitis, the progressive form of NAFLD. Therefore, the main treatment is the pursuit of a healthy lifestyle for both children and adults, which includes a diet rich in fruits, nuts, seeds, whole grains, fish and chicken and avoiding overconsumption of ultra-processed food, red meat, sugar-sweetened beverages and foods cooked at high heat. Physical activity at a level where one can talk but not sing is also recommended, including leisure-time activities and structured exercise. Avoidance of smoking and alcohol is also recommended. Policy-makers, community and school leaders need to work together to make their environments healthy by developing walkable and safe spaces with food stores stocked with culturally appropriate and healthy food items at affordable prices as well as providing age-appropriate and safe play areas in both schools and neighbourhoods.

The Impact and Burden of Dietary Sugars on the Liver

NAFLD, or metabolic dysfunction-associated steatotic liver disease, has increased in prevalence hand in hand with the rise in obesity and increased free sugars in the food supply. The causes of NAFLD are genetic in origin combined with environmental drivers of the disease phenotype. Dietary intake of added sugars has been shown to have a major role in the phenotypic onset and progression of the disease. Simple sugars are key drivers of steatosis, likely through fueling de novo lipogenesis, the conversion of excess carbohydrates into fatty acids, but also appear to upregulate lipogenic metabolism and trigger hyperinsulinemia, another driver. NAFLD carries a clinical burden as it is associated with obesity, type 2 diabetes, metabolic syndrome, and cardiovascular disease. Patient quality of life is also impacted, and there is an enormous economic burden due to healthcare use, which is likely to increase in the coming years. This review aims to discuss the role of dietary sugar in NAFLD pathogenesis, the health and economic burden, and the promising potential of sugar reduction to improve health outcomes for patients with this chronic liver disease.

The intestinal-hepatic axis: a comprehensive review on fructose metabolism and its association with mortality and chronic metabolic diseases

Fructose is a common ingredient of food industry in the form of sucrose and high fructose corn sirup (HFCS). Due to its unique metabolic properties, excessive intake of fructose has been linked to various diseases, including obesity, nonalcoholic fatty liver disease (NAFLD), cardiovascular disease (CVD), chronic renal insufficiency, and even increase the risk of death. Interestingly, although high fructose intake may induce gout, it does not cause hyperuricemia, and the underlying molecular mechanisms remain debated. While previous studies focused on the liver as the primary site of fructose metabolism, recent evidence has suggested a crucial role for the intestine-hepatic axis in fructose metabolism. Low dose fructose is mainly metabolized in the small intestine. Only when the intake exceeds the intestine's metabolic capacity fructose spills over to be metabolized in the liver. High fructose diets also have a significant impact on the diversity of the gut microbiota, leading to alterations in the metabolic byproducts produced by these gut bacteria and thereby inducing endotoxemia. This paper provides a comprehensive review of the epidemiological and pathological studies conducted in recent years, describing the metabolic differences between fructose and glucose and the possible mechanisms underlying the link between excessive fructose intake and chronic metabolic diseases.

Sugar and Dyslipidemia: A Double-Hit, Perfect Storm

The availability of sugar has expanded over the past 50 years, due to improved industrial processes and corn subsidies, particularly in the form of sweetened beverages. This correlates with a surge in the prevalence of cardiometabolic disorders, which has brought this issue back into the spotlight for public health. In this narrative review, we focus on the role of fructose in the genesis of cardiometabolic dyslipidemia (an increase in serum triglyceride-rich lipoproteins (TRL): VLDL, chylomicrons (CM), and their remnants) bringing together the most recent data on humans, which demonstrates the crucial interaction between glucose and fructose, increasing the synthesis while decreasing the catabolism of these particles in a synergistic downward spiral. After reviewing TRL metabolism, we discuss the fundamental principles governing the metabolism of fructose in the intestine and liver and the effects of dysregulated fructolysis, in conjunction with the activation of carbohydrate-responsive element-binding protein (ChREBP) by glucose and the resulting crosstalk. The first byproduct of fructose catabolism, fructose-1-P, is highlighted for its function as a signaling molecule that promotes fat synthesis. We emphasize the role of fructose/glucose interaction in the liver, which enhances de novo lipogenesis, triglyceride (TG) synthesis, and VLDL production. In addition, we draw attention to current research that demonstrates how fructose affects the activity of lipoprotein lipase by increasing the concentration of inhibitors such as apolipoprotein CIII (apoCIII) and angiopoietin-like protein 3 (ANGPTL3), which reduce the catabolism of VLDL and chylomicrons and cause the building up of their atherogenic remnants. The end outcome is a dual, synergistic, and harmful action that encourages atherogenesis. Thus, considering the growing concerns regarding the connection between sugar consumption and cardiometabolic disease, current research strongly supports the actions of public health organizations aimed at reducing sugar intake, including dietary guidance addressing "safe" limits for sugar consumption.

Non-alcoholic Steatohepatitis in Asians: Current Perspectives and Future Directions

Non-alcoholic steatohepatitis (NASH) is a subset of non-alcoholic fatty liver disease (NAFLD), which, apart from excess fat in the liver, may be characterised by some level of inflammatory infiltration and fibrogenesis, occasionally progressing to liver cirrhosis or hepatocellular carcinoma (HCC). The objective of the current review is to elucidate the rising prevalence, the role of microbiome and genetics in pathogenesis, diagnostic challenges, and novel treatment alternatives for NASH. Newer diagnostic techniques are being developed since using liver biopsy in a larger population is not a reasonable option and is primarily restricted to clinical research, at least in developing countries. Besides these technical challenges, another important factor leading to deviation from guideline practice is the lack of health insurance coverage in countries like India. It leads to reluctance on the part of physicians and patients to delay required tests to curb out-of-pocket expenditure. There is no cure for NASH, with liver transplantation remaining the last option for those who progress to end-stage liver disease (ESLD) or are detected with early-stage HCC. Thus, lifestyle modification remains the only viable option for many, but compliance and long-term adherence remain major challenges. In obese individuals, bariatric surgery and weight reduction have shown favourable results. In patients with less severe obesity, endoscopic bariatric metabolic therapies (EBMT) are rapidly emerging as less invasive therapies. However, access and acceptability remain poor for these weight reduction methods. Therefore, intense research is being conducted for potential newer drug classes with several agents currently in phase II or III of clinical development. Some of these have demonstrated promising results, such as a reduction in hepatic fat content, and attenuation of fibrosis with an acceptable tolerability profile in phase II studies. The developments in the management of NASH have been fairly encouraging. Further well-designed long-term prospective studies should be undertaken to generate evidence with definitive results.

The impact of dietary fructose on gut permeability, microbiota, abdominal adiposity, insulin signaling and reproductive function

The excessive intake of fructose in the regular human diet could be related to global increases in metabolic disorders. Sugar-sweetened soft drinks, mostly consumed by children, adolescents, and young adults, are the main source of added fructose. Dietary high-fructose can increase intestinal permeability and circulatory endotoxin by changing the gut barrier function and microbial composition. Excess fructose transports to the liver and then triggers inflammation as well as de novo lipogenesis leading to hepatic steatosis. Fructose also induces fat deposition in adipose tissue by stimulating the expression of lipogenic genes, thus causing abdominal adiposity. Activation of the inflammatory pathway by fructose in target tissues is thought to contribute to the suppression of the insulin signaling pathway producing systemic insulin resistance. Moreover, there is some evidence that high intake of fructose negatively affects both male and female reproductive systems and may lead to infertility. This review addresses dietary high-fructose-induced deteriorations that are obvious, especially in gut permeability, microbiota, abdominal fat accumulation, insulin signaling, and reproductive function. The recognition of the detrimental effects of fructose and the development of relevant new public health policies are necessary in order to prevent diet-related metabolic disorders.

You Are What You Eat: A Review on Dietary Interventions for Treating Pediatric Nonalcoholic Fatty Liver Disease

As the obesity pandemic worsens, cases of pediatric nonalcoholic fatty liver disease (NAFLD) and complications of this disease, such as progressive liver failure, in young adults will continue to rise. Lifestyle changes in the form of dietary modifications and exercise are currently first-line treatments. Large pediatric-specific randomized controlled trials to support specific interventions are currently lacking. A variety of dietary modifications in children with NAFLD have been suggested and studied with mixed results, including low-sugar and high-protein diets, the Mediterranean diet, and the Dietary Approach to Stop Hypertension (DASH). The roles of dietary supplements such as Vitamin E, polyunsaturated fatty acids (PUFAs), ginger, and probiotics have also been investigated. A further understanding of specific dietary interventions and supplements is needed to provide both generalizable and sustainable dietary recommendations to reverse the progression of NAFLD in the pediatric population.

Problems and Challenges Associated with Renaming Non-alcoholic Fatty Liver Disease to Metabolic Associated Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has become the world’s largest chronic liver disease in the 21st century, affecting 20%–30% of the world’s population. As the epidemiology, etiology, and pathogenesis of NAFLD have been studied in-depth, it has been gradually recognized that most patients with NAFLD have one or more combined metabolic abnormalities known as metabolic syndrome. In 2020, the international expert group changed the name of NAFLD to metabolic-associated fatty liver disease (MAFLD) and proposed new diagnostic criteria for MAFLD and MAFLD-related liver cirrhosis, as well as the conceptual framework of other cause-related fatty liver diseases to avoid diagnosis based on the exclusion of other causes and better reflect its pathogenesis. However, there are still many ambiguities in the term, and changing the name does not address the unmet key needs in the field. The change from NAFLD to MAFLD was not just a change of definition. The problems and challenges are summarized as follows: epidemiology, children, rationality of “metabolism,” diagnostic criteria, double/multiple causes, drug discovery, clinical trials, and awareness raising. Metabolic-associated fatty liver disease has complex disease characteristics, and there are still some problems that need to be solved.

Triglyceride-Rich Lipoprotein Metabolism: Key Regulators of Their Flux

The residual risk for arteriosclerotic cardiovascular disease after optimal statin treatment may amount to 50% and is the consequence of both immunological and lipid disturbances. Regarding the lipid disturbances, the role of triglyceride-rich lipoproteins (TRLs) and their remnants has come to the forefront in the past decade. Triglycerides (TGs) stand as markers of the remnants of the catabolism of TRLs that tend to contain twice as much cholesterol as compared to LDL. The accumulation of circulating TRLs and their partially lipolyzed derivatives, known as "remnants", is caused mainly by ineffective triglyceride catabolism. These cholesterol-enriched remnant particles are hypothesized to contribute to atherogenesis. The aim of the present narrative review is to briefly summarize the main pathways of TRL metabolism, bringing to the forefront the newly discovered role of apolipoproteins, the key physiological function of lipoprotein lipase and its main regulators, the importance of the fluxes of these particles in the post-prandial period, their catabolic rates and the role of apo CIII and angiopoietin-like proteins in the partition of TRLs during the fast-fed cycle. Finally, we provide a succinct summary of the new and old therapeutic armamentarium and the outcomes of key current trials with a final outlook on the different methodological approaches to measuring TRL remnants, still in search of the gold standard.