Uric acid induces hepatic steatosis by generation of mitochondrial oxidative stress: potential role in fructose-dependent and -independent fatty liver

Maternal protein restriction combined with postnatal sugar consumption alters liver proteomic profile and metabolic pathways in adult male offspring rats

This study investigated the impact of maternal protein restriction (MPR) and early postnatal sugar consumption (SUG) on the liver health of adult male descendant rats. Male offspring of mothers fed a normal protein diet (NPD) or a low protein diet (LPD) were divided into four groups: Control (CTR), Sugar Control (CTR + SUG), LPD during gestation and lactation (GLLP), and LPD with sugar (GLLP + SUG). Sugar consumption (10% glucose diluted in water) began after weaning on day 21 (PND 21), and at 90 days (PND 90), rats were sacrificed for analysis. Sugar intake reduced food intake and increased water consumption in CTR + SUG and GLLP + SUG compared to CTR and GLLP. GLLP and GLLP + SUG groups showed lower body weight and total and retroperitoneal fat compared to CTR and CTR + SUG. CTR + SUG and GLLP + SUG groups exhibited hepatocyte vacuolization associated with increased hepatic glycogen content compared to CTR and GLLP. Hepatic catalase activity increased in GLLP compared to CTR. Proteomic analysis identified 223 differentially expressed proteins (DEPs) among experimental groups. While in the GLLP group, the DEPs enriched molecular pathways related to cellular stress, glycogen metabolic pathways were enriched in the GLLP + SUG and CTR + SUG groups. The association of sugar consumption amplifies the effects of MPR, deregulating molecular mechanisms related to metabolism and the antioxidant system.

Uric acid and metabolic syndrome: Importance of hyperuricemia cut-off

BACKGROUND

The relationship between HyperUricemia (HU) and Metabolic Sindrome (MS) and if Uric Acid (UA) should be inserted into MS definitions is a matter of debate. Aim of our study was to evaluate the correlation between UA and HU with Insulin Resistance (IR) and MS in a population of hypertensive patients. HU was defined with two cut-offs (the classic one of ≥6 mg/dL for women and ≥ 7 for men; the newly proposed URRAH one with ≥5.6 mg/dL for both sexes).

METHODS

We enrolled 473 Hypertensive patients followed by the Hypertension Unit of San Gerardo Hospital (Monza, Italy). IR was defined through TG/HDL ratio and NCEP-ATP-III criteria were used for MS diagnosis.

RESULTS

MS was found in 33.6 % while HU affected 14.8 % of subjects according to the traditional cut-off and 35.9 % with the URRAH cut-off. 9.7 % (traditional cut-off) and 17.3 % (URRAH's threshold) of the subjects had both HU and MS. UA level was significantly higher in MS group (5.7 vs 4.9 mg/dL, p < 0.0001) as well as for HU (29.0 vs 7.6 % and 51.6 vs 28.0 %, for classic and URRAH cut-off respectively, p < 0.0001 for both comparison). Logistic multivariable regression models showed that UA is related to MS diagnosis (OR = 1.608 for each 1 mg/dL), as well as HU with both cut-off (OR = 5.532 and OR = 3.379, p < 0.0001 for all comparison, for the classic cut-off and the URRAH one respectively).

CONCLUSIONS

The main finding of our study is that UA and HU significantly relate to IR and MS. The higher the values of UA and the higher the cut-off used, the higher the strength of the relationship.

Mechanisms of heart failure and chronic kidney disease protection by SGLT2 inhibitors in nondiabetic conditions

Sodium-glucose cotransporter 2 inhibitors (SGLT2is), initially developed for type 2 diabetes (T2D) treatment, have demonstrated significant cardiovascular and renal benefits in heart failure (HF) and chronic kidney disease (CKD), irrespective of T2D. This review provides an analysis of the multifaceted mechanisms underlying the cardiorenal benefits of SGLT2i in HF and CKD outside of the T2D context. Eight major aspects of the protective effects of SGLT2i beyond glycemic control are explored: 1) the impact on renal hemodynamics and tubuloglomerular feedback; 2) the natriuretic effects via proximal tubule Na+/H+ exchanger NHE3 inhibition; 3) the modulation of neurohumoral pathways with evidence of attenuated sympathetic activity; 4) the impact on erythropoiesis, not only in the context of local hypoxia but also systemic inflammation and iron regulation; 5) the uricosuria and mitigation of the hyperuricemic environment in cardiorenal syndromes; 6) the multiorgan metabolic reprogramming including the potential induction of a fasting-like state, improvement in glucose and insulin tolerance, and stimulation of lipolysis and ketogenesis; 7) the vascular endothelial growth factor A (VEGF-A) upregulation and angiogenesis, and 8) the direct cardiac effects. The intricate interplay between renal, neurohumoral, metabolic, and cardiac effects underscores the complexity of SGLT2i actions and provides valuable insights into their therapeutic implications for HF and CKD. Furthermore, this review sets the stage for future research to evaluate the individual contributions of these mechanisms in diverse clinical settings.

Dietary approaches for controlling cancer by limiting the Warburg effect: a review

Cancer is a mysterious disease. Among other alterations, tumor cells, importantly, have metabolic modifications. A well-known metabolic modification commonly observed in cancer cells has been termed the Warburg effect. This phenomenon is defined as a high preference for glucose uptake, and increased lactate production from that glucose, even when oxygen is readily available. Some anti-cancer drugs target the proposed Warburg effect, and some dietary regimens can function similarly. However, the most suitable dietary strategies for treating particular cancers are not yet well understood. The aim of this review was to describe findings regarding the impact of various proposed dietary regimens targeting the Warburg effect. The evidence suggests that combining routine cancer therapies with diet-based strategies may improve the outcome in treating cancer. However, designing individualized therapies must be our ultimate goal.

Effect of Hepatic Impairment on the Pharmacokinetics and Pharmacodynamics of SHR4640, a Selective Human Urate Transporter 1 Inhibitor

This parallel-group, open-label Phase I study evaluated the effect of mild to moderate hepatic impairment on pharmacokinetics (PK), pharmacodynamics (PD), and safety of a single oral dose of SHR4640. Participants with mild or moderate hepatic impairment were enrolled, with each cohort consisting of eight individuals, alongside eight well-matched controls with normal hepatic function. The participants were administered 10 mg SHR4640, and blood samples were collected for PK evaluation over 72 h. Additionally, serum uric acid (sUA) levels were measured to assess PD changes. Safety was evaluated through adverse events, laboratory tests, vital signs, and electrocardiograms. The Cmax of SHR4640 decreased by 15.0% in the mild hepatic impairment group (geometric least squares means of the ratios [GMR] = 0.850, 90% CI: 0.701-1.03) and by 17.5% in the moderate hepatic impairment group (GMR = 0.825, 90% CI: 0.681-1.00). These reductions were not statistically significant compared to the normal hepatic function group. AUC0-t and AUC0-inf were similar across all groups, indicating that overall exposure to the drug was not clinical significantly affected by hepatic impairment. Apparent clearance and volume of distribution of SHR4640 showed no association with the severity of hepatic impairment as measured by the Child-Pugh score. There were no significant differences in the changes in sUA levels from baseline across different levels of hepatic function. SHR4640 is well tolerated in participants with mild or moderate hepatic impairment. Mild and moderate hepatic impairment did not have a clinically relevant impact on PK, PD, and safety of SHR4640. SHR4640 can be used in patients with mild to moderate hepatic impairment without the need for dose adjustment.

Beta vulgaris L. var cicla Decreases Liver Injury Induced by Antiarrhytmic Agent, Amiodarone

Amiodarone (AMD) is an effective antiarrhythmic drug, but its long-term usage strongly forms liver toxicity due to its accumulation tendency. The chard (Beta vulgaris L. var. cicla) is a unique plant which has a blood sugar-lowering effect and powerful antioxidant activity. The aim of the current study was to investigate the possible protective effects of chard on AMD-induced liver injury. Male Sprague-Dawley rats were divided into four groups. Control group, aqueous chard extract given group 500 mg/kg/day for one week, AMD given group 100 mg/kg/day for one week, AMD+Chard given group (at the same doses and times). They were sacrificed on the 8th day. The blood and liver samples were taken. The serum and liver biochemical parameters were found to be changed in AMD treated group. Chard administration reversed these parameters in serum and liver. In histological experiments, necrotic areas, mononuclear cell infiltration, the endothelial rupture in central vein, sinusoidal dilatation, hyperemia, dark eosinophilic cells and picnotic nucleus were observed in liver tissues of AMD treated group. Chard treatment reduced liver tissue damage. Considering results, we can suggest that chard prevented AMD induced liver injury biochemically and histologically.

Fructose vs. glucose: modulating stem cell growth and function through sugar supplementation

In multicellular organisms, stem cells are impacted by microenvironmental resources such as nutrient availability and oxygen tension for their survival, growth, and differentiation. However, the accessibility of these resources in the pericellular environment greatly varies from organ to organ. This divergence in resource availability leads to variations in the potency and differentiation potential of stem cells. This study aimed to explore the distinct effects of glucose and fructose, as well as different oxygen tensions, on the growth dynamics, cytokine production, and differentiation of stem cells. We showed that replacing glucose with fructose subjected stem cells to stress, resulting in increased Hif1α expression and stability, which in turn led to a reduction in cell proliferation, and alterations in cytokine production. However, fructose failed to induce differentiation of human mesenchymal stem cells (hMSCs) as well as mouse fibroblasts into mature adipocytes compared to glucose, despite the upregulation of key markers of adipogenesis, including C/EBPβ, and PPARγ. Conversely, we showed that fructose induced undifferentiated mouse fibroblasts to release cytokines associated with senescence, including IL1α1, IL6, IL8, MCP1, and TNF1α, suggesting that these cells were undergoing lipolysis. Taken together, our results suggest that altering the culture conditions through changes in hexose levels and oxygen tension places considerable stress on stem cells. Additional research is required to further characterize the mechanisms governing stem cell response to their microenvironments.

Exosome prospects in the diagnosis and treatment of non-alcoholic fatty liver disease

The growing prevalence of NAFLD and its global health burden have provoked considerable research on possible diagnostic and therapeutic options for NAFLD. Although various pathophysiological mechanisms and genetic factors have been identified to be associated with NAFLD, its treatment remains challenging. In recent years, exosomes have attracted widespread attention for their role in metabolic dysfunctions and their efficacy as pathological biomarkers. Exosomes have also shown tremendous potential in treating a variety of disorders. With increasing evidence supporting the significant role of exosomes in NAFLD pathogenesis, their theragnostic potential has become a point of interest in NAFLD. Expectedly, exosome-based treatment strategies have shown promise in the prevention and amelioration of NAFLD in preclinical studies. However, there are still serious challenges in preparing, standardizing, and applying exosome-based therapies as a routine clinical option that should be overcome. Due to the great potential of this novel theragnostic agent in NAFLD, further investigations on their safety, clinical efficacy, and application standardization are highly recommended.

The relationship between the systemic immune inflammation index and the nonalcoholic fatty liver disease in American adolescents

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a growing health crisis in the general population of the United States (U.S.), but the relationship between systemic immune-inflammation (SII) index and NAFLD is not known.

METHODS

We collected data from the National Health and Nutrition Examination Survey 2017-2018. Next, propensity score matching (PSM), collinearity analysis, restricted cubic spline (RCS) plot, logistic regression, quantile regression analysis, subgroup analysis, mediation analysis, and population attributable fraction were used to explore the association of the SII with risk of NAFLD.

RESULTS

A total of 665 participants including the 532 Non-NAFLD and 133 NAFLD were enrolled for further analysis after PSM analysis. The RCS results indicated that there was a linear relationship between the SII and controlled attenuation parameter (p for nonlinear = 0.468), the relationship also existed after adjustment for covariates (p for nonlinear = 0.769). The logistic regression results indicated that a high SII level was an independent risk factor for NAFLD (OR = 3.505, 95% CI: 1.092-11.249, P < 0.05). The quantile regression indicated that at higher quantiles (0.90, and 0.95) the SII was significantly associated with NAFLD (p < 0.05). Mediation analysis indicated that alanine aminotransferase (ALT), triglycerides, and blood urea nitrogen (BUN) were partially contribute to the relationship between SII and NAFLD. The population attributable fractions indicated that 23.19% (95% CI: 8.22%, 38.17%) of NAFLD cases could be attributed to SII corresponding to 133 NAFLD cases.

CONCLUSION

There was a positive linear relationship between the SII and the risk of NAFLD. The ALT, triglycerides, and BUN had a partial mediating effect on the relationship between the SII and NAFLD.

Hepatocyte programmed cell death: the trigger for inflammation and fibrosis in metabolic dysfunction-associated steatohepatitis

By replacing and removing defective or infected cells, programmed cell death (PCD) contributes to homeostasis maintenance and body development, which is ubiquitously present in mammals and can occur at any time. Besides apoptosis, more novel modalities of PCD have been described recently, such as necroptosis, pyroptosis, ferroptosis, and autophagy-dependent cell death. PCD not only regulates multiple physiological processes, but also participates in the pathogenesis of diverse disorders, including metabolic dysfunction-associated steatotic liver disease (MASLD). MASLD is mainly classified into metabolic dysfunction-associated steatotic liver (MASL) and metabolic dysfunction-associated steatohepatitis (MASH), and the latter putatively progresses to cirrhosis and hepatocellular carcinoma. Owing to increased incidence and obscure etiology of MASH, its management still remains a tremendous challenge. Recently, hepatocyte PCD has been attracted much attention as a potent driver of the pathological progression from MASL to MASH, and some pharmacological agents have been proved to exert their salutary effects on MASH partly via the regulation of the activity of hepatocyte PCD. The current review recapitulates the pathogenesis of different modalities of PCD, clarifies the mechanisms underlying how metabolic disorders in MASLD induce hepatocyte PCD and how hepatocyte PCD contributes to inflammatory and fibrotic progression of MASH, discusses several signaling pathways in hepatocytes governing the execution of PCD, and summarizes some potential pharmacological agents for MASH treatment which exert their therapeutic effects partly via the regulation of hepatocyte PCD. These findings indicate that hepatocyte PCD putatively represents a new therapeutic point of intervention for MASH.

Activation of AMPD2 drives metabolic dysregulation and liver disease in mice with hereditary fructose intolerance

Hereditary fructose intolerance (HFI) is a painful and potentially lethal genetic disease caused by a mutation in aldolase B resulting in accumulation of fructose-1-phosphate (F1P). No cure exists for HFI and treatment is limited to avoid exposure to fructose and sugar. Using aldolase B deficient mice, here we identify a yet unrecognized metabolic event activated in HFI and associated with the progression of the disease. Besides the accumulation of F1P, here we show that the activation of the purine degradation pathway is a common feature in aldolase B deficient mice exposed to fructose. The purine degradation pathway is a metabolic route initiated by adenosine monophosphate deaminase 2 (AMPD2) that regulates overall energy balance. We demonstrate that very low amounts of fructose are sufficient to activate AMPD2 in these mice via a phosphate trap. While blocking AMPD2 do not impact F1P accumulation and the risk of hypoglycemia, its deletion in hepatocytes markedly improves the metabolic dysregulation induced by fructose and corrects fat and glycogen storage while significantly increasing the voluntary tolerance of these mice to fructose. In summary, we provide evidence for a critical pathway activated in HFI that could be targeted to improve the metabolic consequences associated with fructose consumption.

Recent Advances on Sex Hormone-Binding Globulin Regulation by Nutritional Factors: Clinical Implications

Sex hormone-binding globulin (SHBG) is a homodimeric glycoprotein produced by the human liver and secreted into the systemic circulation where it binds with high affinity sex steroids regulating their availability in blood and accessibility to target tissues. Plasma SHBG levels are altered in metabolic disorders such as obesity, anorexia, and insulin resistance. Several reports have shown that diets in terms of total calories or fat, fiber, or protein content can alter plasma SHBG levels. However, there are many components in a diet that can affect SHBG gene expression in the liver. In order to unravel the molecular mechanisms by which diets regulate SHBG production, it would be necessary to analyze single diet components and/or nutritional factors. This review summarizes the recent advances in identifying different nutritional factors regulating SHBG production and the related molecular mechanism, as well as the clinical implications.

A study on the early metabolic effects of salt and fructose consumption: the protective role of water

Increasing serum osmolality has recently been linked with acute stress responses, which over time can lead to increased risk for obesity, hypertension, and other chronic diseases. Salt and fructose are two major stimuli that can induce acute changes in serum osmolality. Here we investigate the early metabolic effects of sodium and fructose consumption and determine whether the effects of sodium or fructose loading can be mitigated by blocking the change in osmolality with hydration. Forty-four healthy subjects without disease and medication were recruited into four groups. After overnight fasting, subjects in Group 1 drank 500 mL of salty soup, while those in Group 2 drank 500 mL of soup without salt for 15 min. Subjects in Group 3 drank 500 mL of 100% apple juice in 5 min, while subjects in Group 4 drank 500 mL of 100% apple juice and 500 mL of water in 5 min. Blood pressure (BP), plasma sodium, and glucose levels were measured every 15 min in the first 2 h. Serum and urine osmolarity, serum uric acid, cortisol, fibroblast growth factor 21 (FGF21), aldosterone, adrenocorticotropic hormone (ACTH) level, and plasma renin activity (PRA) were measured at the baseline and 2 h. Both acute intake of salt or fructose increased serum osmolality (maximum ∼4 mOsm/L peaking at 75 min) associated with a rise in systolic and diastolic BP, PRA, aldosterone, ACTH, cortisol, plasma glucose, uric acid, and FGF21. Salt tended to cause greater activation of the renin-angiotensin-system (RAS), while fructose caused a greater rise in glucose and FGF21. In both cases, hydration could prevent the osmolality and largely block the acute stress response. Acute changes in serum osmolality can induce remarkable activation of the ACTH-cortisol, RAS, glucose metabolism, and uric acid axis that is responsive to hydration. In addition to classic dehydration, salt, and fructose-containing sugars can activate these responses. Staying well hydrated may provide benefits despite exposure to sugar and salt. More studies are needed to investigate whether hydration can block the chronic effects of sugar and salt on disease.

Correlation between serum uric acid to high-density lipoprotein cholesterol ratio and atrial fibrillation in patients with NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is independently associated with atrial fibrillation (AF) risk. The uric acid (UA) to high-density lipoprotein cholesterol (HDL-C) ratio (UHR) has been shown to be closely associated with cardiovascular disease (CVD) and NAFLD. The aim of this study is to clarify whether elevated UHR is associated with the occurrence of AF in patients with NAFLD and to determine whether UHR predicted AF.

METHODS

Patients diagnosed with NAFLD in the Department of Cardiovascular Medicine of the Second Hospital of Shanxi Medical University from January 1, 2020, to December 31, 2021, were retrospectively enrolled in this study. The study subjects were categorized into AF group and non-AF group based on the presence or absence of combined AF. Logistic regression was performed to evaluate the correlation between UHR and AF. Sensitivity analysis and subgroup interaction analysis were performed to verify the robustness of the study results. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff value for UHR to predict the development of AF in patients with NAFLD.

RESULTS

A total of 421 patients with NAFLD were included, including 171 in the AF group and 250 in the non-AF group. In the univariate regression analysis, NAFLD patients with higher UHR were more likely to experience AF, and the risk of AF persisted after confounding factors were adjusted for (OR: 1.010, 95%CI: 1.007-1.013, P<0.001). AF risk increased with increasing UHR quartile (P for trend < 0.001). Despite normal serum UA and HDL-C, UHR was still connected with AF in patients with NAFLD. All subgroup variables did not interact significantly with UHR in the subgroup analysis. The ROC curve analysis showed that the areas under the curve for UA, HDL-C, and UHR were 0.702, 0.606, and 0.720, respectively, suggesting that UHR has a higher predictive value for AF occurrence in NAFLD patients compared to HDL-C or UA alone.

CONCLUSION

Increased UHR level was independently correlated with a high risk of AF in NAFLD patients.

Association of serum uric acid with hypertriglyceridemia in children and adolescents: a cross-sectional study

BACKGROUND

Uric acid (UA), a liver-derived metabolite, is intimately tied to metabolic disorders. Although ample research underscores its connection with hypertriglyceridemia (HTG), studies focusing on adolescents remain limited. To fill the gaps in epidemiology,this study focused on analyzing the relationship between the levels of uric acid and HTG in a demographic sample comprising adolescents from the United States.

METHODS

In this study, a total of 4,435 participants through the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020. The exposure variable was serum uric acid (SUA), the effect variable was HTG, and the covariates included demographic, questionnaire, physical examination and laboratory indicators. We utilized weighted logistic regression and meticulous subgroup evaluations to discern the intrinsic link between SUA and HTG. Stratified analyses augmented the validation of this association, while smooth curve fitting probed for potential nonlinear correlations.

RESULTS

The study included 4,435 participants. Male adolescents exhibit elevated SUA levels. After adjusting for all variables, the weighted multiple logistic regression model revealed that SUA was positively correlated with HTG risk (OR = 1.006, 95% CI: 1.005-1.007). This relationship was consistent across the three tertiles group of SUA (T1: OR = 1.006 [95% CI: 1.005-1.007]; T2: OR = 1.006 [95% CI: 1.005-1.007]; T3: OR = 1.004 [95% CI: 1.003-1.006]; P for trend < 0.001). Stratified analyses confirmed that the positive correlation between SUA and HTG risk was significant, irrespective of sex, age or race.

CONCLUSIONS

In American children and adolescents aged 12 to 18 years, there was a pronounced association between SUA and HTG. SUA could serve as a risk indicator for HTG. It is recommended that children diagnosed with HTG should be regularly tested for SUA levels. In addition, it is recommended that SUA be included in the comprehensive care of children diagnosed with HTG.

The positive association between hyperuricemia and polycystic ovary syndrome and analysis of related factors

Purpose

To examine the potential association between polycystic ovary syndrome (PCOS) and hyperuricemia and to elucidate the underlying contributory factors.

Methods

Retrospective study on 603 women with PCOS and 604 women without PCOS. Anthropometric features, reproductive hormone profiles, and metabolic parameters were measured and compared between two groups of patients. Examinations of correlations between SUA levels and other parameters were conducted to discern potential correlations.

Results

Both serum uric acid levels and the incidence of hyperuricemia exhibited statistically significant elevations in women with PCOS when compared to their counterparts without PCOS. Nonetheless, this statistical difference was not found between the obese subgroup after stratifying study subjects by body mass index (BMI). Pearson's correlation analysis underscored the prominence of BMI as a robust factor influencing SUA levels in women, regardless of their PCOS status. Furthermore, multivariable linear regression model demonstrated significant positive associations between SUA levels and several variables, namely dehydroepiandrosterone sulfate (DHEA-S), free androgen index (FAI), total cholesterol (TC), triglycerides (TG), free fatty acids (FFA), fasting insulin (FINS), homeostatic model assessment of insulin resistance (HOMA-IR), area under the curve for insulin (AUC-I), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Additionally, it is noteworthy that the prevalence of hyperuricemia exhibited a positive association with fasting plasma glucose (FPG) levels, while conversely, it displayed a negative association with estradiol (E2) levels.

Conclusions

PCOS is associated with a significant elevation of SUA level and hyperuricemia prevalence. HA, IR, and dyslipidemia may be the mediators in the pathogenesis of hyperuricemia in women with PCOS.

The Metabolic and Endocrine Effects of a 12-Week Allulose-Rich Diet

The global rise in type 2 diabetes (T2D) and obesity necessitates innovative dietary interventions. This study investigates the effects of allulose, a rare sugar shown to reduce blood glucose, in a rat model of diet-induced obesity and T2D. Over 12 weeks, we hypothesized that allulose supplementation would improve body weight, insulin sensitivity, and glycemic control. Our results showed that allulose mitigated the adverse effects of high-fat, high-sugar diets, including reduced body weight gain and improved insulin resistance. The allulose group exhibited lower food consumption and increased levels of glucagon-like peptide-1 (GLP-1), enhancing glucose regulation and appetite control. Additionally, allulose prevented liver triglyceride accumulation and promoted mitochondrial uncoupling in adipose tissue. These findings suggest that allulose supplementation can improve metabolic health markers, making it a promising dietary component for managing obesity and T2D. Further research is needed to explore the long-term benefits and mechanisms of allulose in metabolic disease prevention and management. This study supports the potential of allulose as a safe and effective intervention for improving metabolic health in the context of dietary excess.

CRISPR/Cas9 Mediated Deletion of the Uox Gene Generates a Mouse Model of Hyperuricemia with Multiple Complications

Hyperuricemia is a common metabolic disorder with severe complications. We aimed to develop a mouse model for spontaneous hyperuricemia. Uox-/- mouse model was generated on C57BL/6J background by deleting exon 2-4 of Uox using the CRISPR/Cas9 system. The prototypic Uox -/-mice had 5.5-fold increased serum uric acid (1351.04±276.58μmol/L) as compared to the wild type mice (P<0.0001), but died by 4 weeks. After allopurinol (3ug/g) intervention, they all survived > 8 weeks. The serum uric acid was 612.55±146.98μmol/L in the 8-week-old allopurinol-rescued Uox -/-mice, which manifested multiple complications including severe renal insufficiency, hypertension, left ventricular remodeling and systolic dysfunction, aortic endothelial dysfunction, hepatic steatosis and elevated liver enzymes, as well as hyperglycemia and hypercholesteremia. The present Uox-/- mice developed spontaneous hyperuricemia complicated with urate nephropathy, cardiovascular disease and cardiometabolic disorders, and may provide a novel tool to study hyperuricemia associated early-onset cardiovascular disorders in human.

Serum Uric Acid, Hypertriglyceridemia, and Carotid Plaques: A Sub-Analysis of the URic Acid Right for Heart Health (URRAH) Study

High levels of serum uric acid (SUA) and triglycerides (TG) might promote high-cardiovascular-risk phenotypes, including subclinical atherosclerosis. An interaction between plaques xanthine oxidase (XO) expression, SUA, and HDL-C has been recently postulated. Subjects from the URic acid Right for heArt Health (URRAH) study with carotid ultrasound and without previous cardiovascular diseases (CVD) (n = 6209), followed over 20 years, were included in the analysis. Hypertriglyceridemia (hTG) was defined as TG ≥ 150 mg/dL. Higher levels of SUA (hSUA) were defined as ≥5.6 mg/dL in men and 5.1 mg/dL in women. A carotid plaque was identified in 1742 subjects (28%). SUA and TG predicted carotid plaque (HR 1.09 [1.04-1.27], p < 0.001 and HR 1.25 [1.09-1.45], p < 0.001) in the whole population, independently of age, sex, diabetes, systolic blood pressure, HDL and LDL cholesterol and treatment. Four different groups were identified (normal SUA and TG, hSUA and normal TG, normal SUA and hTG, hSUA and hTG). The prevalence of plaque was progressively greater in subjects with normal SUA and TG (23%), hSUA and normal TG (31%), normal SUA and hTG (34%), and hSUA and hTG (38%) (Chi-square, 0.0001). Logistic regression analysis showed that hSUA and normal TG [HR 1.159 (1.002 to 1.341); p = 0.001], normal SUA and hTG [HR 1.305 (1.057 to 1.611); p = 0.001], and the combination of hUA and hTG [HR 1.539 (1.274 to 1.859); p = 0.001] were associated with a higher risk of plaque. Our findings demonstrate that SUA is independently associated with the presence of carotid plaque and suggest that the combination of hyperuricemia and hypertriglyceridemia is a stronger determinant of carotid plaque than hSUA or hTG taken as single risk factors. The association between SUA and CVD events may be explained in part by a direct association of UA with carotid plaques.

Depletion of hepatic glutathione and adenosine by glucocorticoid exposure in Wistar rats is pregnancy-independent

Liver diseases have gained increasing attention due to their substantial impact on health, independently as well as in association with cardio-metabolic disorders. Studies have suggested that glutathione and adenosine assist in providing protection against oxidative stress and inflammation while glucocorticoid (GC) therapy has been associated with chronic inflammatory disorders, even in pregnancy. The implications of Glucocorticoid exposure on maternal health and fetal growth is a concern, however, the possible role of glutathione and adenosine has not been thoroughly investigated. The study therefore hypothesize that exposure to glucocorticoids leads to depletion of hepatic glutathione and adenosine levels, contributing to oxidative stress and tissue injury. Additionally, we aim to investigate whether the effects of glucocorticoids on hepatic health are pregnancy dependent in female rats. Twelve Pregnant and twelve age-matched non-pregnant rats were used for this study; an exogenous administration of glucocorticoid (Dex: 0.2 mg/kg) or vehicle (po) was administered to six pregnant and six non-pregnant rats from gestational day 14 to 19 or for a period of 6 days respectively. Data obtained showed that GC exposure led to a decrease in hepatic glucose-6-phosphate dehydrogenase, glutathione peroxidase, GSH/GSSG ratio and adenosine content in both pregnant and non-pregnant rats. In addition, increased activities of adenosine deaminase and xanthine oxidase, along with increased production of uric acid and increased levels of lactate dehydrogenase, aspartate aminotransferase, alanine transferase, alkaline phosphatase and gamma-glutamyl transferase were observed. In summary, the study indicates that GC-induced liver damage is underlined by depleted hepatic adenosine and glutathione levels as well as elevated markers of tissue inflammation and/or injury. Furthermore, the findings suggest that the effects of GC exposure on hepatic health are pregnancy independent.

Low preoperative serum uric acid is associated with early acute kidney injury after living donor liver transplantation

BACKGROUND

Liver transplantation is treatment option for patients with end-stage liver disease and hepatocellular carcinoma. Renal function deterioration significantly impacts the survival rates of liver recipients, and serum uric acid (SUA) is associated with both acute and chronic renal function disorders. Thus, our study aimed to assess the relationship and predictive value of preoperative SUA level and postoperative acute kidney injury (AKI) in living donor liver transplantation (LDLT).

METHODS

We conducted a prospective observational study on 87 patients undergoing LDLT. Blood samples were collected immediately before LDLT, and renal function status was followed up for 3 consecutive days postoperatively.

RESULTS

Low SUA levels (cutoff value 4.15 mg/dL) were associated with a high risk of early posttransplantation AKI. The area under the curve was 0.73 (sensitivity, 79.2%; specificity, 59.4%). Although not statistically significant, there were no deaths in the non-AKI group but two in the early AKI group secondary to liver graft dysfunction in addition to early AKI within the first month after LDLT.

CONCLUSION

AKI after liver transplantation may lead to a deterioration of patient status and increased mortality rates. We determined low preoperative SUA levels as a possible risk factor for early postoperative AKI.

Single photon emission computed tomography/computed tomography imaging of gouty arthritis: A new voice

Gouty arthritis, often referred to simply as gout, is a disorder of purine metabolism characterized by the deposition of monosodium urate monohydrate (MSU) crystals in multiple systems and organs, especially in joints and their surrounding soft tissue. Gout is a treatable chronic disease, and the main strategy for effective management is to reverse the deposition of MSU crystals by uric acid reduction, and to prevent gout attacks, tophi deposition and complications, and thereby improve the quality of life. However, the frequent association of gout with other conditions such as hypertension, obesity, cardiovascular disease, diabetes, dyslipidemia, chronic kidney disease (CKD) and kidney stones can complicate the treatment of gout and lead to premature death. Here, we review the use of medical imaging techniques for studying gouty arthritis with special interest in the potential role of single photon emission computed tomography (SPECT)/computed tomography (CT) in the clinical management of gout and complications (e.g., chronic kidney disease and cardiovascular disease).

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.

A genome-first approach to variants in MLXIPL and their association with hepatic steatosis and plasma lipids

BACKGROUND

Common variants of the max-like protein X (MLX)-interacting protein-like (MLXIPL) gene, encoding the transcription factor carbohydrate-responsive element-binding protein, have been shown to be associated with plasma triglyceride levels. However, the role of these variants in steatotic liver disease (SLD) is unclear.

METHODS

We used a genome-first approach to analyze a variety of metabolic phenotypes and clinical outcomes associated with a common missense variant in MLXIPL, Gln241His, in 2 large biobanks: the UK Biobank and the Penn Medicine Biobank.

RESULTS

Carriers of MLXIPL Gln241His were associated with significantly lower serum levels of triglycerides, apolipoprotein-B, gamma-glutamyl transferase, and alkaline phosphatase. Additionally, MLXIPL Gln241His carriers were associated with significantly higher serum levels of HDL cholesterol and alanine aminotransferase. Carriers homozygous for MLXIPL Gln241His showed a higher risk of SLD in 2 unrelated cohorts. Carriers of MLXIPL Gln241His were especially more likely to be diagnosed with SLD if they were female, obese, and/or also carried the PNPLA3 I148M variant. Furthermore, the heterozygous carriage of MLXIPL Gln241His was associated with significantly higher all-cause, liver-related, and cardiovascular mortality rates. Nuclear magnetic resonance metabolomics data indicated that carriage of MLXIPL Gln241His was significantly associated with lower serum levels of VLDL and increased serum levels of HDL cholesterol.

CONCLUSIONS

Analyses of the MLXIPL Gln241His polymorphism showed a significant association with a higher risk of SLD diagnosis and elevated serum alanine aminotransferase as well as significantly lower serum triglycerides and apolipoprotein-B levels. MLXIPL might, therefore, be a potential pharmacological target for the treatment of SLD and hyperlipidemia, notably for patients at risk. More mechanistic studies are needed to better understand the role of MLXIPL Gln241His on lipid metabolism and steatosis development.

Fructose-induced metabolic reprogramming of cancer cells

Excess dietary fructose consumption has been long proposed as a culprit for the world-wide increase of incidence in metabolic disorders and cancer within the past decades. Understanding that cancer cells can gradually accumulate metabolic mutations in the tumor microenvironment, where glucose is often depleted, this raises the possibility that fructose can be utilized by cancer cells as an alternative source of carbon. Indeed, recent research has increasingly identified various mechanisms that show how cancer cells can metabolize fructose to support their proliferating and migrating needs. In light of this growing interest, this review will summarize the recent advances in understanding how fructose can metabolically reprogram different types of cancer cells, as well as how these metabolic adaptations can positively support cancer cells development and malignancy.

Unlocking the Therapeutic Potential of Ellagic Acid for Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis

Obesity is in epidemic proportions in many parts of the world, contributing to increasing rates of non-alcoholic fatty liver disease (NAFLD). NAFLD represents a range of conditions from the initial stage of fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to severe fibrosis, through to hepatocellular carcinoma. There currently exists no treatment for the long-term management of NAFLD/NASH, however, dietary interventions have been investigated for the treatment of NASH, including several polyphenolic compounds. Ellagic acid is one such polyphenolic compound. Nutraceutical food abundant in ellagic acid undergoes initial hydrolysis to free ellagic acid within the stomach and small intestine. The proposed mechanism of action of ellagic acid extends beyond its initial therapeutic potential, as it is further broken down by the gut microbiome into urolithin. Both ellagic acid and urolithin have been found to alleviate oxidative stress, inflammation, and fibrosis, which are associated with NAFLD/NASH. While progress has been made in understanding the pharmacological and biological activity of ellagic acid and its involvement in NAFLD/NASH, it has yet to be fully elucidated. Thus, the aim of this review is to summarise the currently available literature elucidating the therapeutic potential of ellagic acid and its microbial-derived metabolite urolithin in NAFLD/NASH.

Sweet regulation - The emerging immunoregulatory roles of hexoses

BACKGROUND

It is widely acknowledged that dietary habits have profound impacts on human health and diseases. As the most important sweeteners and energy sources in human diets, hexoses take part in a broad range of physiopathological processes. In recent years, emerging evidence has uncovered the crucial roles of hexoses, such as glucose, fructose, mannose, and galactose, in controlling the differentiation or function of immune cells.

AIM OF REVIEW

Herein, we reviewed the latest research progresses in the hexose-mediated modulation of immune responses, provided in-depth analyses of the underlying mechanisms, and discussed the unresolved issues in this field.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Owing to their immunoregulatory effects, hexoses affect the onset and progression of various types of immune disorders, including inflammatory diseases, autoimmune diseases, and tumor immune evasion. Thus, targeting hexose metabolism is becoming a promising strategy for reversing immune abnormalities in diseases.

Association between serum uric acid and deep venous thrombosis in European populations: A two-sample Mendelian randomization study

BACKGROUND AND AIM

Previous experimental and observational studies showed that serum uric acid (SUA) was associated with deep venous thrombosis (DVT), but the causal relationship is unclear. This study aimed to explore the potential causal association between SUA and DVT.

METHODS AND RESULTS

We designed a two-sample Mendelian randomization (MR) analysis by using summary-level data from large genome-wide association studies performed in European individuals. A total of 14 SUA-related single-nucleotide polymorphisms (SNPs) (P value < 5 × 10-8) were identified as instrumental variables. The inverse variance weighted method was used as the primary method to compute the odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for per standard deviation increase in SUA. MR Egger, weighted median, weighted mode, and simple mode were also applied to test the robustness of the results. We found no significant causal effects of serum uric acid on deep venous thrombosis (odds ratio [OR]: 1.000, 95 % confidence interval [CI]: 0.998-1.002, p = 0.78) by using inverse variance weighted. MR analyses based on other methods showed similar results.

CONCLUSIONS

There was no potential causal associations between higher genetically predicted SUA levels and increased risk of deep venous thrombosis. Further, MR studies with more valid SNPs and more DVT cases are needed. Validation of the findings is also recommended.

Uric acid in health and disease: From physiological functions to pathogenic mechanisms

Owing to renal reabsorption and the loss of uricase activity, uric acid (UA) is strictly maintained at a higher physiological level in humans than in other mammals, which provides a survival advantage during evolution but increases susceptibility to certain diseases such as gout. Although monosodium urate (MSU) crystal precipitation has been detected in different tissues of patients as a trigger for disease, the pathological role of soluble UA remains controversial due to the lack of causality in the clinical setting. Abnormal elevation or reduction of UA levels has been linked to some of pathological status, also known as U-shaped association, implying that the physiological levels of UA regulated by multiple enzymes and transporters are crucial for the maintenance of health. In addition, the protective potential of UA has also been proposed in aging and some diseases. Therefore, the role of UA as a double-edged sword in humans is determined by its physiological or non-physiological levels. In this review, we summarize biosynthesis, membrane transport, and physiological functions of UA. Then, we discuss the pathological involvement of hyperuricemia and hypouricemia as well as the underlying mechanisms by which UA at abnormal levels regulates the onset and progression of diseases. Finally, pharmacological strategies for urate-lowering therapy (ULT) are introduced, and current challenges in UA study and future perspectives are also described.

Fructose-induced hyperuricaemia - protection factor or oxidative stress promoter?

Accumulating evidence suggests that dietary fructose may play a role in the hyperuricaemia development, but the precise mechanism remains unclear. Hyperuricaemia is characterised by excessive production and deposition of urate crystals, and the metabolism of fructose has been implicated in the elevation of serum urate levels. The association between fructose intake and the risk of hyperuricaemia is explained by the metabolism of fructose in the liver, small intestine, and kidney. Many studies have confirmed the correlation between fructose consumption and an increased risk of developing hyperuricaemia, but more prospective studies to fully elucidate the role of fructose intake in the pathogenesis of hyperuricaemia are needed. It is important to note that maintaining a balanced diet, and lifestyle is crucial when considering fructose intake. Limiting the consumption of products high in added sugars and maintaining a healthy weight can contribute to reducing the risk of hyperuricaemia and associated health complications.

Untargeted metabolomics reveals the regulatory effect of geniposidic acid on lipid accumulation in HepG2 cells and Caenorhabditis elegans and validation in hyperlipidemic hamsters

BACKGROUND

Geniposidic acid (GPA) alleviates oxidative stress and inflammation in mice However, whether it can effectively regulate lipid accumulation and prevent hyperlipidemia requires further investigation.

PURPOSE

This study combined the untargeted metabolomics of cells and a Caenorhabditis elegans model to evaluate the anti-hyperlipidemic potential of GPA by modulating oxidative stress and regulating lipid metabolism. A golden hamster model of hyperlipidemia was used to further validate the lipid-lowering effect and mechanism of action of GPA.

METHODS

Chemical staining, immunofluorescence, and flow cytometry were performed to examine the effects of GPA on lipid accumulation and oxidative stress. Untargeted metabolomic analysis of cells and C. elegans was performed using ultra-performance liquid chromatography coupled with quadrupole electrostatic field Orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap MS) to identify biomarkers altered by GPA action, analyze the affected metabolic pathways, and validate the mechanisms by which GPA regulates lipid metabolism and oxidative stress. A golden hamster model of hyperlipidemia was established to test the lipid-lowering effects of GPA. Body weight, biochemical markers, rate-limiting enzymes, and key proteins were assessed. Hematoxylin and eosin (H&E) and Oil Red O staining were performed.

RESULTS

Phenotypic data showed that GPA decreased free fatty acid (FFA)-induced lipid buildup and high reactive oxygen species (ROS) levels, reversed the decrease in mitochondrial membrane potential (MMP), and increased the cellular reduced glutathione/oxidized glutathione disulfide (GSH/GSSG) ratio. GPA also reduces high glucose-induced lipid build-up and ROS production in C. elegans. Metabolomic analysis showed that GPA affected purine, lipid, and amino acid metabolism. Moreover, GPA inhibited xanthine oxidase (XOD), glutamate dehydrogenase (GLDH), fatty acid synthase (FAS), phosphorylation of P38 MAPK, and upregulated the expression of SIRT3 and CPT1A protein production to control lipid metabolism and produce antioxidant benefits in cells and golden hamsters.

CONCLUSION

Current evidence suggests that GPA can effectively regulate lipid metabolism and the oxidative stress response, and has the potential to prevent hyperlipidemia. This study also provided an effective method for evaluating the mechanism of action of GPA.

Can uric acid affect the immune microenvironment in bladder cancer? A single-center multi-omics study

Metabolic abnormalities are one of the important factors in bladder cancer (BCa) progression and microenvironmental disturbance. As an important product of purine metabolism, uric acid's (UA) role in BCa metabolism and immunotherapy remains unclear. In this study, we conducted a retrospective analysis of a cohort comprising 39 BCa patients treated with PD-1 and 169 patients who underwent radical cystectomy at Shanghai Tenth People's Hospital. Kaplan-Meier curves and Cox regression analysis showed that the prognosis of patients with high UA is worse (p = 0.007), and high UA is an independent risk factor for cancer specific survival in patients with BCa (p = 0.025). We established a hyperuricemia mouse model with BCa subcutaneous xenografts in vivo. The results revealed that the subcutaneous tumors of hyperuricemia mice had a greater weight and volume in comparison with the control group. Through flow cytometric analysis, the proportion of CD8+ and CD4+ T cells in these subcutaneous tumors was seen to decline significantly. We also evaluated the relationship of UA and BCa by muti-omic analysis. UA related genes were significantly increased in the CD8+ T cell of non-responders to immunotherapy by single-cell sequencing. An 11-gene UA related signature was constructed and the risk score negatively correlated with various immune cells and immune checkpoints. Finally, a nomogram was established using a UA related signature to forecast the survival rate of patients with BCa. Collectively, this study demonstrated that UA was an independent prognostic biomarker for BCa and was associated with worse immunotherapy response.

Exploring Promising Therapies for Non-Alcoholic Fatty Liver Disease: A ClinicalTrials.gov Analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is a common disease and has been increasing in recent years. To date, no FDA-approved drug specifically targets NAFLD.

Methods

The terms "Non-alcoholic Fatty Liver Disease" and "NAFLD" were used in a search of ClinicalTrials.gov on August 24, 2023. Two evaluators independently examined the trials using predetermined eligibility criteria. Studies had to be interventional, NAFLD focused, in Phase IV, and completed to be eligible for this review.

Results

The ClinicalTrials.gov database was searched for trials examining pharmacotherapeutics in NAFLD. The search revealed 1364 trials, with 31 meeting the inclusion criteria. Out of these, 19 were finalized for evaluation. The dominant intervention model was Parallel. The most prevalent studies were in Korea (26.3%) and China (21.1%). The most common intervention was metformin (12.1%), with others like Exenatide and Pioglitazone accounting for 9.1%.

Conclusion

Therapeutics used to manage NAFLD are limited. However, various medications offer potential benefits. Further investigations are definitely warranted.

One-hour post-load glucose levels are associated with hepatic steatosis assessed by transient elastography

AIM

To examine the association between 1-hour plasma glucose (PG) concentration and markers of non-alcoholic fatty liver disease (NAFLD) assessed by transient elastography (TE).

METHODS

We performed TE in 107 metabolically well-characterized non-diabetic White individuals. Controlled attenuation parameter (CAP) was used to quantify liver steatosis, while liver stiffness marker (LS) was used to evaluate fibrosis.

RESULTS

Controlled attenuation parameter correlated significantly with 1-hour PG (r = 0.301, P < 0.01), fasting insulin (r = 0.285, P < 0.01), 2-hour insulin (r = 0.257, P < 0.02), homeostasis model assessment index of insulin resistance (r = 0.252, P < 0.01), high-density lipoprotein cholesterol (r = -0.252, P < 0.02), body mass index (BMI; r = 0.248, P < 0.02) and age (r = 0.212, P < 0.03), after correction for age, sex and BMI. In a multivariable linear regression analysis, 1-hour PG (β = 0.274, P = 0.008) and fasting insulin levels (β = 0.225, P = 0.029) were found to be independent predictors of CAP. After excluding subjects with prediabetes, 1-hour PG was the sole predictor of CAP variation (β = 0.442, P < 0.001). In a logistic regression model, we observed that the group with 1-hour PG ≥  8.6 mmol/L (155 mg/dL) had a significantly higher risk of steatosis (odds ratio 3.98, 95% confidence interval 1.43-11.13; P = 0.008) than individuals with 1-hour PG <  8.6 mmol/L, after correction for potential confounders. No association was observed between 1-hour PG and LS.

CONCLUSION

Our data confirm that 1-hour PG ≥  8.6 mmol/L is associated with higher signs of NAFLD, even among individuals with normal glucose tolerance, categorized as low risk by canonical diagnostic standards. TE is a safe low-impact approach that could be employed for stratifying the risk profile in these patients, with a high level of accuracy.

The Intersection of Genetic Factors, Aberrant Nutrient Metabolism and Oxidative Stress in the Progression of Cardiometabolic Disease

Cardiometabolic disease (CMD), which encompasses metabolic-associated fatty liver disease (MAFLD), chronic kidney disease (CKD) and cardiovascular disease (CVD), has been increasing considerably in the past 50 years. CMD is a complex disease that can be influenced by genetics and environmental factors such as diet. With the increased reliance on processed foods containing saturated fats, fructose and cholesterol, a mechanistic understanding of how these molecules cause metabolic disease is required. A major pathway by which excessive nutrients contribute to CMD is through oxidative stress. In this review, we discuss how oxidative stress can drive CMD and the role of aberrant nutrient metabolism and genetic risk factors and how they potentially interact to promote progression of MAFLD, CVD and CKD. This review will focus on genetic mutations that are known to alter nutrient metabolism. We discuss the major genetic risk factors for MAFLD, which include Patatin-like phospholipase domain-containing protein 3 (PNPLA3), Membrane Bound O-Acyltransferase Domain Containing 7 (MBOAT7) and Transmembrane 6 Superfamily Member 2 (TM6SF2). In addition, mutations that prevent nutrient uptake cause hypercholesterolemia that contributes to CVD. We also discuss the mechanisms by which MAFLD, CKD and CVD are mutually associated with one another. In addition, some of the genetic risk factors which are associated with MAFLD and CVD are also associated with CKD, while some genetic risk factors seem to dissociate one disease from the other. Through a better understanding of the causative effect of genetic mutations in CMD and how aberrant nutrient metabolism intersects with our genetics, novel therapies and precision approaches can be developed for treating CMD.

Associations of Serum Uric Acid to High-Density Lipoprotein Cholesterol Ratio with Trunk Fat Mass and Visceral Fat Accumulation

Background

It has been reported recently that the ratio of uric acid to high-density lipoprotein cholesterol (UHR) is correlated with several metabolic disorders. The present study aimed to investigate the associations of UHR with body fat content and distribution.

Methods

This study enrolled 300 participants (58 men and 242 women) aged 18 to 65 years. The levels of serum uric acid and high-density lipoprotein cholesterol were measured by standard enzymatic methods. The overall fat content and segmental fat distribution were assessed with an automatic bioelectrical impedance analyzer. In the population with obesity, the visceral fat area (VFA) and subcutaneous fat area (SFA) were measured using magnetic resonance imaging.

Results

Among the study population, 219 individuals (73.0%) were with obesity. The median level of UHR in individuals with obesity was 33.7% (26.2% - 45.9%), which was significantly higher than that in those without obesity [22.6% (17.0% - 34.4%), P < 0.01]. UHR was positively associated with overall fat content and segmental fat distribution parameters (all P < 0.01). In multivariate linear regression analysis, compared with body mass index, waist circumference was more closely associated with UHR (standardized β = 0.427, P < 0.001) after adjusting for confounding factors. Additionally, total fat mass (standardized β = 0.225, P = 0.002) and trunk fat mass (standardized β = 0.296, P = 0.036) were more closely linked to UHR than total fat-free mass and leg fat mass, respectively. In the population with obesity, VFA was independently correlated with UHR (P < 0.01), while SFA was not associated with UHR.

Conclusion

UHR was significantly associated with overall fat content and trunk fat accumulation. In the population with obesity, UHR was positively associated with VFA. Attention should be paid to the role of excessive trunk fat mass in the relationship between UHR and metabolic disorders.

Xanthine oxidase inhibitors treatment or discontinuation effects on mortality: evidence of xanthine oxidase inhibitors withdrawal syndrome

Objectives: This study investigates the impact of xanthine oxidase inhibitors (XOI) on mortality in patients with cardiovascular diseases. XOI withdrawal has been reported to increased mortality risk due to rapid adenosine triphosphate (ATP) deficiency. This study aims to determine whether XOI treatment reduces mortality and whether XOI withdrawal increases mortality. Methods: This is a real-world database study using the Japanese Registry of All Cardiac and Vascular Diseases (J-ROAD). We analyzed 1,648,891 hospitalized patients aged 20-90 with acute coronary syndrome or heart failure. In the first study, mortality rates were compared between patients without urate-lowering agents (n = 1,292,486) and those with XOI agents (n = 315,388, excluding 41,017 on other urate-lowering agents). In the second study, mortality rates were compared between the XOI continuous medication group (n = 226,261) and the XOI withdrawal group (n = 89,127). Results: After multiple adjustments, XOI treatment group showed significantly lower mortality compared with that without any urate-lowering agent (odds ratio (OR), 0.576, 95% confidence interval (CI), 0.567-0.587, p < .001). In the sub-analysis, the group with allopurinol (OR, 0.578; 95% CI, 0.557-0.600), febuxostat (OR, 0.610; 95% CI, 0.599-0.622), and topiroxostat (HR, 0.545; 95% CI, 0.473-0.628) showed lower OR of mortality compared with that without any urate-lowering agent. XOI withdrawal group led to significantly higher death rates compared to XOI continuous group (19.8% vs. 0.03%; p < .001). Conclusion: XOI treatment for patients with cardiovascular diseases is associated with reduced mortality. Conversely, XOI withdrawal is linked to elevated mortality risk. This emphasizes the importance of both prescribing and discontinuing XOI carefully to optimize patient outcomes.

Longitudinal changes in high sensitivity C-reactive protein associated with serum uric acid in the Korean Genome and Epidemiology Study

Cross-sectional studies support the role of serum uric acid (SUA) in inflammation, but evidence from cohort studies is scarce. Longitudinal associations between SUA and high-sensitivity C-reactive protein (hs-CRP) were examined in the general population. Data for participants from the Health Examinees-Gem cohort (n = 50,028; 40-69 years; 67% women) who were examined between 2004 and 2013 and followed up until 2016 were analyzed. SUA and hs-CRP were measured at baseline and during follow-up. SUA was evaluated as a continuous variable and was also divided into sex-specific quartiles. Mean hs-CRP levels at follow-up were evaluated using multivariable proportional odds regression, with non-linear smoothed baseline hs-CRP levels serving as a covariate. Selected pathological markers were also examined in relation to hs-CRP. Increased levels of SUA at baseline were related to increased levels of hs-CRP at follow-up [regression coefficient per mg/dL increase in baseline SUA (β) = 0.08, 95% confidence interval (CI), 0.040-0.128]. A dose-response relationship was observed, (P for linear trend = 0.0015). The mean values of hs-CRP were highest among participants with the highest follow-up but lowest baseline SUA levels. Elevated hs-CRP levels at follow up (> 3 mg/L) were positively related to fasting blood glucose levels, triglycerides levels, liver enzymes, and blood pressure, but negatively related to high density lipoprotein cholesterol levels per unit increase in baseline hs-CRP. High SUA levels were associated with high hs-CRP levels, suggesting a potential role of SUA in inflammation. However, additional research is needed to confirm these findings.

Prevalence and association of hyperuricemia with liver function in Saudi Arabia: a large cross-sectional study

BACKGROUND

Hyperuricemia is linked to an increased risk of various chronic diseases, but data on the prevalence and association of hyperuricemia with liver function in Saudi Arabia are scarce.

OBJECTIVES

Evaluate the prevalence, association, and risk measures of hyperuricemia and liver function in the Saudi population.

DESIGN

Retrospective, cross-sectional analysis.

SETTING

Database on large portion of Saudi population.

PATIENTS AND METHODS

Laboratory data, age, and gender of the studied subjects were collected from Al Borg Diagnostics. Subjects were stratified, based on their uric acid (UA) levels, into three groups: hypouricemic, normouricemic, and hyperuricemic. The association of UA with liver enzymes was examined in all three groups.

MAIN OUTCOME MEASURES

Association of serum UA levels with alanine transaminase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), and total bilirubin (TB).

SAMPLE SIZE

13 314 subjects.

RESULTS

Our study showed that the prevalence of hyperuricemia in the Saudi population is 17.3% (20.3% in males and 15.1% in females). We also found a positive correlation between ALT, AST, and TB with UA levels. The risk of being hyperuricemic was significantly increased in individuals with elevated ALT, AST, and TB. Individuals with elevated ALT, AST, and total TB had a higher chance of having hyperuricemia than those with normal activity. Notably, ALT, AST, and TB had good discriminating capacity for hyperuricemia.

CONCLUSIONS

Hyperuricemia is highly prevalent in the Saudi population and is associated with compromised liver function. However, further studies are needed to elucidate the mechanisms underlying these findings in large prospective cohort studies in different populations.

LIMITATIONS

Lack of data on other potential confounding variables.

Correlation of serum uric acid levels with certain anthropometric parameters in prediabetic and drug-naive diabetic subjects

Introduction

Uric acid is produced during the metabolism of nucleotide and adenosine triphosphate and contains the final product of human purine metabolism. It acts both as an antioxidant and pro-inflammatory marker and has a positive association with visceral fat in overweight subjects. The aim of the present study is to find an association of uric acid level with certain anthropometric parameters in subjects having type 2 diabetes.

Materials and Methods

The study included 124 urban drug-naive diabetic Indian subjects above 18 years of age from the general population of the city of North India. Uric acid concentrations were estimated by the uricase method. Fasting plasma glucose (FPG) concentrations were estimated by the glucose oxidase-peroxidase method. Anthropometric measurements and information on lifestyle factors and disease history were collected through in-person meeting.

Results

All participants of the study subjects had a body mass index (BMI) of more than 23.5. BMI, waist-to-hip ratio (WHR), waist-to-height ratio, waist circumference, neck circumference, weight, age, sagittal abdominal diameter (SAD), skinfold thickness, and body roundness index were positively correlated with the serum uric acid level. The correlation of weight, BMI, SAD, and WHR was statistically significant.

Conclusion

We found that serum uric acid level increases as body fat content increases. Statistical data show remarkable results for a significant correlation of uric acid level with BMI, WHR, SAD, and FPG. Hypertrophy occurs as a result of inflammatory processes and oxidative stress when the supply of energy starts to exceed the storage capacity of adipocytes, as a result, adipokines such as interleukin (IL)-1, IL-6, and tumor-necrosis factor-alpha are released more frequently which lead to low-grade chronic inflammation. Uric acid levels are much lean toward visceral obesity than overall body fat content.

The fructose survival hypothesis as a mechanism for unifying the various obesity hypotheses

The pathogenesis of obesity remains contested. Although genetics is important, the rapid rise in obesity with Western culture and diet suggests an environmental component. Today, some of the major hypotheses for obesity include the energy balance hypothesis, the carbohydrate-insulin model, the protein-leverage hypothesis, and the seed oil hypothesis. Each hypothesis has its own support, creating controversy over their respective roles in driving obesity. Here we propose that all hypotheses are largely correct and can be unified by another dietary hypothesis, the fructose survival hypothesis. Fructose is unique in resetting ATP levels to a lower level in the cell as a consequence of suppressing mitochondrial function, while blocking the replacement of ATP from fat. The low intracellular ATP levels result in carbohydrate-dependent hunger, impaired satiety (leptin resistance), and metabolic effects that result in the increased intake of energy-dense fats. This hypothesis emphasizes the unique role of carbohydrates in stimulating intake while fat provides the main source of energy. Thus, obesity is a disorder of energy metabolism, in which there is low usable energy (ATP) in the setting of elevated total energy. This leads to metabolic effects independent of excess energy while the excess energy drives weight gain.

Time- and Concentration-Dependent Stimulation of Oxidative Stress in Chondrocytes by Intracellular Soluble Urate

BACKGROUND

Gout could result in irreversible bone erosion, and chondrocyte might be involved in the process. Increased soluble urate is the early stage of gout and is strongly oxidative.

OBJECTIVE

To explore the effect of intracellular urate on the oxidative status of chondrocytes.

METHODS

A chondrocyte model was used. Serial concentrations of exogenous urate were incubated with chondrocytes for increasing amounts of time. Reactive oxygen species (ROS), oxidant, and anti-oxidant molecules were measured with biochemical assays, rt-PCR, and western blot. A urate transport inhibitor and oxidative inhibitors were used to confirm the effect of exogenous urate.

RESULTS

All concentrations of exogenous urate stimulated the production of ROS in a time- and concentration-dependent manner, as well as oxidant molecules, including hydrogen peroxide (H2O2), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, nitric oxide (NO) inducible nitric oxide synthase (iNOS), and these effects, could be inhibited by oxidant inhibitors. However, anti-oxidant molecules, including acidic leucine-rich nuclear phosphoprotein-32A (ANP32A), ataxia-telangiectasia mutated (ATM), heme oxygenase-1 (HO-1), and the transcription factor nuclear factor erythroid 2 (NF-E2)-related (Nrf2), was decreased by high concentrations of exogenous urate after prolonged incubation, but not by low to medium concentrations of exogenous urate. By inhibiting soluble urate trafficking, benzbromarone significantly suppressed the effect of urate stimulus on the oxidant and anti-oxidant molecules.

CONCLUSION

Intracellular soluble urate could regulate chondrocyte redox balance in a time and concentration-dependent manner, and would be a target for regulating and protecting chondrocyte function in the early gout stage.

Different dietary carbohydrate component intakes and long-term outcomes in patients with NAFLD: results of longitudinal analysis from the UK Biobank

BACKGROUND

This study aimed to investigate the association between the intake of different dietary carbohydrate components and the long-term outcomes of non-alcoholic fatty liver disease (NAFLD).

METHODS

We used prospective data from 26,729 NAFLD participants from the UK Biobank cohort study. Dietary information was recorded by online 24-hour questionnaires (Oxford WebQ). Consumption of different carbohydrate components was calculated by the UK Nutrient Databank Food Composition Table. Cox proportional hazards models were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI). A substitution model was used to estimate the associations of hypothetical substitution for free sugars.

RESULTS

During a median of 10.5 (IQR: 10.2-11.2) years and a total of 280,135 person-years of follow-up, 310 incident end-stage liver disease (ESLD) and 1750 deaths were recorded. Compared with the lowest quartile, the multi-adjusted HRs (95% CI) of incident ESLD in the highest quartile were 1.65 (1.14-2.39) for free sugars, 0.51 (0.35-0.74) for non-free sugars, and 0.55 (0.36-0.83) for fiber. For overall mortality, the multi-adjusted HRs (95% CI) in the highest quartile were 1.21 (1.04-1.39) for free sugars, 0.79 (0.68-0.92) for non-free sugars, and 0.79 (0.67-0.94) for fiber. Substituting free sugars with equal amounts of non-free sugars, starch or fiber was associated with a lower risk of incident ESLD and overall mortality.

CONCLUSIONS

A lower intake of free sugars and a higher intake of fiber are associated with a lower incidence of ESLD and overall mortality in NAFLD patients. These findings support the important role of the quality of dietary carbohydrates in preventing ESLD and overall mortality in NAFLD patients.

Fructose: a modulator of intestinal barrier function and hepatic health?

PURPOSE

Consumption of fructose has repeatedly been discussed to be a key factor in the development of health disturbances such as hypertension, diabetes type 2, and non-alcoholic fatty liver disease. Despite intense research efforts, the question if and how high dietary fructose intake interferes with human health has not yet been fully answered.

RESULTS

Studies suggest that besides its insulin-independent metabolism dietary fructose may also impact intestinal homeostasis and barrier function. Indeed, it has been suggested by the results of human and animal as well as in vitro studies that fructose enriched diets may alter intestinal microbiota composition. Furthermore, studies have also shown that both acute and chronic intake of fructose may lead to an increased formation of nitric oxide and a loss of tight junction proteins in small intestinal tissue. These alterations have been related to an increased translocation of pathogen-associated molecular patterns (PAMPs) like bacterial endotoxin and an induction of dependent signaling cascades in the liver but also other tissues.

CONCLUSION

In the present narrative review, results of studies assessing the effects of fructose on intestinal barrier function and their impact on the development of health disturbances with a particular focus on the liver are summarized and discussed.

Machine Learning Insights Into Uric Acid Elevation With Thiazide Therapy Commencement and Intensification

Background Elevated serum uric acid, associated with cardiovascular conditions such as atherosclerotic heart disease, hypertension, and heart failure, can be elevated by thiazide or thiazide-like drugs (THZ), essential in hypertension management. Identifying clinical determinants affecting THZ-related uric acid elevation is critical. Methods In this retrospective cross-sectional study, we explored the clinical determinants influencing uric acid elevation related to THZ, focusing on patients where THZ was initiated or the dose escalated. A cohort of 143 patients was analyzed, collecting baseline and control uric acid levels, alongside basic biochemical studies and clinical data. Feature selection was conducted utilizing criteria based on mean squared error increase and enhancement in node purity. Four machine learning algorithms - Random Forest, Neural Network, Support Vector Machine, and Gradient Boosting regressions - were applied to pinpoint clinical influencers. Results Significant features include uncontrolled diabetes, index estimated Glomerular Filtration Rate (eGFR) level, absence of insulin, action of indapamide, and absence of statin treatment, with absence of Sodium-glucose cotransporter 2 inhibitors (SGLT2i), low dose aspirin exposure, and older age also being noteworthy. Among the applied models, the Gradient Boosting regression model outperformed the others, exhibiting the lowest Mean Absolute Error (MAE), Mean Squared Error (MSE), Root Mean Squared Error (RMSE) values, and the highest R2 value (0.779). While Random Forest and Neural Network regression models were able to fit the data adequately, the Support Vector Machine demonstrated inferior metrics. Conclusions Machine learning algorithms are adept at accurately identifying the factors linked to uric acid fluctuations caused by THZ. This proficiency aids in customizing treatments more effectively, reducing the need to unnecessarily avoid THZ, and providing guidance on its use to prevent instances where uric acid levels could become problematic.

Do macronutrient intakes affect obesity indices in Jordanian adults?

OBJECTIVE

To determine whether macronutrient intake is associated with novel obesity indices, including the conicity index (CI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), and weight-adjusted-waist index (WWI).

METHODOLOGY

A cross-sectional survey was conducted with 491 adults (344 males and 147 females) working at different universities in Jordan (July-December 2019). Daily intake of energy (kcal), carbohydrates (g), protein (g), and fat (g) was obtained using 24-h recalls collected over 2 days. Additionally, obesity indices were calculated.

RESULTS

Regardless of sex, energy, and carbohydrate intakes had a moderately significant positive association, whereas protein and fat intakes had a weakly significant association with BAI, AVI, and BRI. CI and WWI showed a weakly significant association with all macronutrients in males, a moderate correlation with energy and carbohydrate intake, and a weak association with fat and protein intake in females. Male participants had significant increases in the CI (T1 = 1.29 ± 0.01 vs. T3 = 1.36 ± 0.01, p = .018), AVI (T1 = 17.96 ± 0.52 vs. T3 = 22.81 ± 0.57, p = .011), and WWI (T1 = 10.72 ± 0.11 vs. T3 = 11.29 ± 0.09, p = .047) indices scores through the carbohydrate intake tertiles. Additionally, there was a significant increase in scores of AVI (T1 = 18.60 ± 0.56 vs. T3 = 21.42 ± 0.46, p = .048) and an almost significant increase in CI (T1 = 1.30 ± 0.01vs. T3 = 1.33 ± 0.01, p = .056) through the tertiles of protein intake.

CONCLUSION

Macronutrients were significantly associated with all indices. The effect of macronutrients on obesity indices is sex-based. Among men, CI, AVI, and WWI were the indices most affected by carbohydrate and protein intakes. Future studies should further investigate food sources and macronutrient quality.

Regulation of Macronutrients in Insulin Resistance and Glucose Homeostasis during Type 2 Diabetes Mellitus

Insulin resistance is an important feature of metabolic syndrome and a precursor of type 2 diabetes mellitus (T2DM). Overnutrition-induced obesity is a major risk factor for the development of insulin resistance and T2DM. The intake of macronutrients plays a key role in maintaining energy balance. The components of macronutrients distinctly regulate insulin sensitivity and glucose homeostasis. Precisely adjusting the beneficial food compound intake is important for the prevention of insulin resistance and T2DM. Here, we reviewed the effects of different components of macronutrients on insulin sensitivity and their underlying mechanisms, including fructose, dietary fiber, saturated and unsaturated fatty acids, and amino acids. Understanding the diet-gene interaction will help us to better uncover the molecular mechanisms of T2DM and promote the application of precision nutrition in practice by integrating multi-omics analysis.

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.

Ketohexokinase-dependent metabolism of cerebral endogenous fructose in microglia drives diabetes-associated cognitive dysfunction

Dementia, as an advanced diabetes-associated cognitive dysfunction (DACD), has become the second leading cause of death among diabetes patients. Given that little guidance is currently available to address the DACD process, it is imperative to understand the underlying mechanisms and screen out specific therapeutic targets. The excessive endogenous fructose produced under high glucose conditions can lead to metabolic syndrome and peripheral organ damage. Although generated by the brain, the role of endogenous fructose in the exacerbation of cognitive dysfunction is still unclear. Here, we performed a comprehensive study on leptin receptor-deficient T2DM mice and their littermate m/m mice and revealed that 24-week-old db/db mice had cognitive dysfunction and excessive endogenous fructose metabolism in the hippocampus by multiomics analysis and further experimental validation. We found that the rate-limiting enzyme of fructose metabolism, ketohexokinase, is primarily localized in microglia. It is upregulated in the hippocampus of db/db mice, which enhances mitochondrial damage and reactive oxygen species production by promoting nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) expression and mitochondrial translocation. Inhibiting fructose metabolism via ketohexokinase depletion reduces microglial activation, leading to the restoration of mitochondrial homeostasis, recovery of structural synaptic plasticity, improvement of CA1 pyramidal neuron electrophysiology and alleviation of cognitive dysfunction. Our findings demonstrated that enhanced endogenous fructose metabolism in microglia plays a dominant role in diabetes-associated cognitive dysfunction and could become a potential target for DACD.

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.