Hyperuricemia Predisposes to the Onset of Diabetes via Promoting Pancreatic β-Cell Death in Uricase-Deficient Male Mice

Metabolic crosstalk and therapeutic interplay between diabetes and hyperuricemia

Hyperuricemia and diabetes mellitus (DM) are prevalent metabolic disorders with high comorbidity, imposing a substantial global public health burden. Their coexistence is not merely additive but synergistic, exacerbating metabolic dysregulation through mechanisms such as insulin resistance and β-cell apoptosis, ultimately establishing a vicious cycle. Both disorders induce acute and chronic damage to vital organs, particularly the cardiovascular, renal systems. Hyperuricemia aggravates diabetic complications, notably diabetic cardiomyopathy, nephropathy and retinopathy via oxidative stress, inflammation, and metabolic dysregulation.Current urate-lowering therapies (ULTs), such as xanthine oxidase inhibitors and urate transporter 1 (URAT1, also known as SLC22A12) antagonists, demonstrate potential benefits in ameliorating diabetic complications but face challenges including safety concerns and dose adjustments. Similarly, several glucose-lowering drugs also exhibit the benefits of improving hyperuricemia. This review summarizes the metabolic crosstalk and therapeutic interplay between hyperuricemia and DM, examines the pathogenic role of uric acid in diabetic complications, and discusses the benefits and challenges of existing ULTs and glucose-lowering drugs in disrupting this cycle of metabolic dysregulation and concurrent organ damage. We hope our findings deepen the comprehension of the intricate metabolic crosstalk between glucose and urate homeostasis, providing novel therapeutic insights for patients with comorbid DM and hyperuricemia.

The new definition of metabolic syndrome including hyperuricemia improves its prognostic value: results from NHANES database

BACKGROUND

Metabolic syndrome (MetS) is a significant global health issue that is strongly associated with an increased risk of cardiovascular disease (CVD). While MetS was initially proposed to identify more high-risk individuals and facilitate early management, hyperuricemia has not yet been included in its definition, despite its strong association with MetS. This study aims to explore the prognostic value of incorporating hyperuricemia into the definition of MetS.

METHODS

Data derived from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2018 were analyzed. The old version of MetS (MetSold) aligned with NCEP-ATP III criteria, whereas the new version of MetS (MetSnew) included hyperuricemia as a sixth criterion. Baseline characteristics were compared between participants with and without MetS, and outcomes were assessed by multivariate analyses.

RESULTS

Among the 36,363 participants analyzed, 12,594 (34.6%) and 14,137 (38.9%) met MetSold and MetSnew criteriarespectively. Compared to MetSold, MetSnew identified additional 1534(4.24%) participants at metabolic risk. Both MetSold and MetSnew were significantly associated with long-term all-cause and CVD mortality (all P < 0.001). Furthermore, the additional participants identified by MetSnew exhibited a similar risk of all-cause and CVD mortality as those meeting MetSold criteria. MetSnew demonstrated enhanced identification and reclassification abilities compared to MetSold, as evidenced by improvement in C-index, NRI and IDI.

CONCLUSIONS

The inclusion of hyperuricemia in the MetS criteria could identify a larger proportion of individuals at metabolic risk, thereby facilitating early management to prevent long-term adverse events.

The link between hyperuricemia and diabetes: insights from a quantitative analysis of scientific literature

Background

Hyperuricemia (HUA) is a significant public health issue, ranking second only to diabetes in prevalence. While existing research demonstrates a robust correlation between these two conditions, the precise etiological mechanisms remain inadequately elucidated. This study utilized scientometric analysis to investigate the global association between HUA and diabetes.

Methods

Data on HUA and diabetes were retrieved from the Web of Science Core Collection database, encompassing the period from its inception until September 30, 2024. Collaboration networks were examined using VOSviewer, cluster analysis was executed with CiteSpace, and systematic mapping was conducted using Bibliometrix.

Results

By September 30, 2024, 1,464 studies indicated a consistent yearly increase in publications connecting HUA and diabetes despite some fluctuations. The lead authors were Richard J. Johnson, Miguel A. Lanaspa, and Masanari Kuwabara, with most contributors from China, the United States, and Japan. Key institutions include China Medical University, Shanghai Jiao Tong University, and Capital Medical University. The most published journal was Nutrition, Metabolism and Cardiovascular Diseases (CVDs), whereas the most cited journal was Diabetes Care. The reference network from 1987 to September 30, 2024, identified 19 clusters highlighting key research areas in HUA and diabetes, such as metabolic syndrome, uropathology, chronic kidney disease (CKD), and CVD. Exploring pathological mechanisms and pharmacological interventions linked to diabetes concomitant with HUA has emerged as a focal point of research and a burgeoning trend within the field.

Conclusion

This study is the first scientometric analysis to synthesize research trends on HUA and diabetes, revealing molecular mechanisms and treatment strategies and providing theoretical insights for future clinical use.

Roles of N6-methyladenosine in LncRNA changes and oxidative damage in cadmium-induced pancreatic β-cells

N6-methyladenosine (m6A) modification and LncRNAs play crucial regulatory roles in various pathophysiological processes, yet roles of m6A modification and the relationship between m6A modification and LncRNAs in cadmium-induced oxidative damage of pancreatic β-cells have not been fully elucidated. In this study, m6A agonist entacapone and inhibitor 3-deazadenosine were used to identify the effects of m6A on cadmium-induced oxidative damage as well as LncRNA changes. Our results indicate that elevated levels of m6A modification by entacapone can rescue the cell viability and attenuate the cell apoptosis, while the inhibition levels of m6A modification can exacerbate the cell death. Furthermore, the elevation of m6A modification can recover cadmium-induced oxidative damage to pancreatic β-cells, which characterized as inhibition the ROS accumulation, MDA contents, protein expressions of Nrf2 and Ho-1, while elevation the expressions of Sod1 and Gclc. On the contrary, the reduction levels of m6A modification can exacerbate the cadmium-induced oxidative damage. More importantly, six significantly differentially expressed LncRNAs were selected according to our preliminary sequencing data (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE253072) and there is a clear correlation between the levels of these LncRNAs and m6A modification after cadmium treatment. Interestingly, the intervention of m6A modification levels can significantly affect the levels of these LncRNAs. In detail, the stimulation of m6A modification reversed the changes of cadmium-induced LncRNAs, while the m6A modification inhibition can significantly exacerbate the changes of cadmium-induced LncRNAs. In conclusion, our data revealed critical roles of m6A modification in cadmium-induced LncRNAs and oxidative damage. Our findings point to a new direction for future studies on the molecular mechanisms of pancreatic β-cell damage induced by cadmium.

Lacticaseibacillus casei JS-2 from 'Jiangshui' Reduces Uric Acid and Modulates Gut Microbiota in Hyperuricemia

Lacticaseibacillus casei (JS-2) is a novel probiotic isolated from "Jiangshui", a kind of traditional folk fermented food, which has a significant effect on hyperuricemia (HUA). In vitro experimental results showed that JS-2 has a high degradation ability and selectivity for uric acid (UA). The animal test results indicated that after two weeks of treatment, JS-2 could significantly reduce the level of UA in the serum of HUA quails (p < 0.01), and its effect is almost equivalent to that of the positive drug control group, benzbromarone. Further, after JS-2 treatment, the level of xanthine oxidase in quail serum decreased significantly. Analysis data of quail fecal metabolomics results showed that JS-2-altering metabolites were involved in amino acid, purine, and lipid metabolism. To investigate the mechanism underlying JS-2-mediated UA degradation in the quail model of HUA, 16S rRNA gene sequencing was conducted. It was found that the structure and function of the gut microbiota were restored after JS-2 intervention, and the abundance of short-chain fatty acid (SCFA)-producing bacteria (g__Ruminococcus_torques_group and g__Butyricicoccus) and bacteria with UA degradation capacity (g__unclassified_f__Lachnospiraceae and g__Negativibacillus) increased significantly; intestinal SCFAs, especially propionic acid, increased accordingly. These experimental data suggest that the beneficial effects of JS-2 may derive from changes in the gut microbiome, altering host-microbiota interactions, reducing UA levels by increasing UA excretion, and reducing absorption. These findings provided new evidence that JS-2 has the potential to be used as a naturally functional food for the prevention of HUA.

Uric acid to albumin ratio is a novel predictive marker for all-cause and cardiovascular death in diabetic patients: a prospective cohort study

Background

Diabetes is one of the leading causes of death with an increasing prevalence worldwide. Diabetes-related premature mortality is largely preventable and reversible if identified and managed early. Accordingly, we intend to investigate the predictive value of uric acid to albumin ratio (UAR) for all-cause and cardiovascular death in diabetic patients.

Methods

Univariate and multivariate Cox regression analyses were performed to identify risk factors for all-cause death of diabetic patients. The receiver operating characteristic (ROC) curves and nomogram model were used to evaluate the predictive ability of variables. Kaplan-Meier survival analysis was used to display the progression risks of diabetic patients.

Results

A total of 804 diabetic patients were enrolled in the study. During the 5-year follow-up, all-cause death was found in 80 participants (9.95%) and cardiovascular death was found in 24 participants (2.99%). Age, UAR, and hsCRP were independent risk factors for all-cause death in diabetic patients after adjusting for potential confounding factors. Age and UAR had good predictive value for 1-, 3-, and 5-year all-cause death in diabetic patients, and the combination of UAR and age had the highest predictive value. An easy and intuitive prognostic nomogram model with good predictive accuracy was constructed based on age and UAR. Patients in higher quantiles of age and UAR had more rapid progression to all-cause death and higher mortality risk than patients in the lower quantiles. UAR also had good predictive value for cardiovascular death in diabetic patients.

Conclusions

UAR may be a simple, cost-effective, and reliable predictive marker for all-cause and cardiovascular death in U.S. diabetic patients. The clinical utility of UAR and nomogram based on age and UAR can help physicians identify individuals at higher risk and therefore promote prevention strategies.

Physicochemical properties, health benefits, and applications of the polysaccharides from Rosa rugosa Thunb.: A review

Rosa rugosa Thunb. (R. rugosa) has been used as food and medicine and not just as ornamental plant for nearly a thousand years, its nutritional and medicinal value have been recognized by people. It contains a variety of biological active ingredients that are beneficial to the human body. R. rugosa polysaccharides are also one of the main bioactive ingredients, which have many health benefits such as anti-diabetes, antioxidation, anti-inflammation, anti-tumour, moisture-preserving and anti-alcoholic liver disease. This review summarizes the extraction, purification, structural characteristics, health benefits, and structure-activity relationships of R. rugosa polysaccharides. In addition, current and potential applications of R. rugosa polysaccharides are analyzed and supplemented, hoping to provide some valuable insights for further research and development of functional food additives, nutritional supplements, additives for daily chemical products, and even pharmaceuticals.

High Fat Mass Index is Associated with Endometrial Hyperplasia in Polycystic Ovary Syndrome Patients: A Retrospective Study

Aim

To assess body composition, glucolipid metabolism, and uric acid levels in PCOS (Polycystic Ovary Syndrome) patients to determine their relationship with the risk of endometrial hyperplasia (EH).

Methods

A total of 232 patients were included and divided into groups according to whether they had PCOS and endometrial pathology (Group A: non-PCOS and normal endometrium; Group B: PCOS and normal endometrium; Group C: non-PCOS and EH; Group D: PCOS and EH). Body composition differences between groups and correlations between body composition, glucolipid metabolism, and uric acid levels were analyzed.

Results

In Group D, the patient's PSM (Percent Skeletal Muscle) of Trunk, PBF (Percent Body Fat) of Arm, free mass index, FMI (Fat Mass Index), and appendicular skeletal muscle mass index were significantly higher than in Groups A, B, and C. Waist-hip rate, PBF, PBF of Trunk, PSM of Leg, skeletal muscle mass index and visceral fat level were significantly higher than in Groups A and B. FMI was an independent risk factor for EH in PCOS patients, the AUC for FMI prediction of endometrial hyperplasia in PCOS patients was 0.82. FMI had significant positive correlations with fasting glucose, fasting insulin, HOMA-IR (Homeostatic Model Assessment for Insulin Resistance), total cholesterol, triglyceride, low-density lipoprotein, triglyceride/high-density lipoprotein, and uric acid levels. FMI was correlated with HOMA-IR and uric acid at 0.602 and 0.649 respectively in PCOS patients.

Conclusion

Increased FMI and altered glucolipid metabolism as key factors associated with a higher risk of EH in patients with PCOS. Monitoring body composition and metabolic health in PCOS patients could help identify those at greater risk of EH, guiding preventive interventions.

Hyperuricemia and epiretinal pathologies: a review of pathophysiological links and clinical implications

Hyperuricemia (HUA), defined by elevated serum uric acid levels, is well-established in its association with systemic conditions like gout and cardiovascular diseases. Recently, however, emerging research has revealed a potential connection between HUA and ocular disorders, particularly epiretinal pathologies. This review investigates the pathophysiological mechanisms linking HUA to epiretinal conditions, including epiretinal membrane formation, macular edema, and retinal vascular diseases. By thoroughly analyzing current literature, this review seeks to deepen the understanding of the relationship between HUA and epiretinal disorders, with the aim of informing new therapeutic strategies and enhancing patient outcomes.

GDF11 improves hippocampal neurogenesis and cognitive abilities in diabetic mice by reducing neural inflammation

BACKGROUND

The cognitive decline associated with type 2 diabetes (T2D) is often attributed to compromised hippocampal neurogenesis and exacerbated neural inflammation. This study investigates the therapeutic potential of growth differentiation factor 11 (GDF11) in reversing these neurodegenerative processes in diabetic mice.

RESULT

We utilized a murine model of T2D and examined the effects of GDF11 on learning, memory, neurogenesis, and neuroinflammatory markers. Our results indicate that diabetic mice exhibit significant deficits in cognitive function, mirrored by reduced hippocampal neurogenesis and increased neuroinflammation. Chronic administration of GDF11 was observed to significantly enhance cognitive abilities, as evidenced by improved performance in learning and memory tasks. Concurrently, GDF11 treatment restored neural activity and promoted the regeneration of new neurons within the hippocampus. Inflammatory profiling revealed a reduction in neuroinflammatory markers, which was further supported by reduced microglia numbers. To delineate the role of neuroinflammation, we pharmacologically depleted microglia, leading to a restoration of neurogenesis and cognitive functions in diabetic mice.

CONCLUSION

These findings endorse the hypothesis that GDF11 exerts its beneficial effects by modulating neuroinflammatory pathways. Consequently, GDF11 represents a promising intervention to ameliorate diabetes-induced cognitive impairments and neural degeneration through its anti-inflammatory properties.

A phenome-wide association and factorial Mendelian randomization study on the repurposing of uric acid-lowering drugs for cardiovascular outcomes

Uric acid has been linked to various disease outcomes. However, it remains unclear whether uric acid-lowering therapy could be repurposed as a treatment for conditions other than gout. We first performed both observational phenome-wide association study (Obs-PheWAS) and polygenic risk score PheWAS (PRS-PheWAS) to identify associations of uric acid levels with a wide range of disease outcomes. Then, trajectory analysis was conducted to explore temporal progression patterns of the observed disease outcomes. Finally, we investigated whether uric acid-lowering drugs could be repurposed using a factorial Mendelian randomization (MR) study design. A total of 41 overlapping phenotypes associated with uric acid levels were identified by both Obs- and PRS- PheWASs, primarily cardiometabolic diseases. The trajectory analysis illustrated how elevated uric acid levels contribute to cardiometabolic diseases, and finally death. Meanwhile, we found that uric acid-lowering drugs exerted a protective role in reducing the risk of coronary atherosclerosis (OR = 0.96, 95%CI: 0.93, 1.00, P = 0.049), congestive heart failure (OR = 0.64, 95%CI: 0.42, 0.99, P = 0.043), occlusion of cerebral arteries (OR = 0.93, 95%CI: 0.87, 1.00, P = 0.044) and peripheral vascular disease (OR = 0.60, 95%CI: 0.38, 0.94, P = 0.025). Furthermore, the combination of uric acid-lowering therapy (e.g. xanthine oxidase inhibitors) with antihypertensive treatment (e.g. calcium channel blockers) exerted additive effects and was associated with a 6%, 8%, 8%, 10% reduction in risk of coronary atherosclerosis, heart failure, occlusion of cerebral arteries and peripheral vascular disease, respectively. Our findings support a role of elevated uric acid levels in advancing cardiovascular dysfunction and identify potential repurposing opportunities for uric acid-lowering drugs in cardiovascular treatment.

Pro-inflammatory diets promote the formation of hyperuricemia

Background

Hyperuricemia, as a very prevalent chronic metabolic disease with increasing prevalence year by year, poses a significant burden on individual patients as well as on the global health care and disease burden, and there is growing evidence that it is associated with other underlying diseases such as hypertension and cardiovascular disease. The association between hyperuricemia and dietary inflammatory index (DII) scores was investigated in this study.

Methods

This study enrolled 13, 040 adult subjects (aged ≥ 20 years) from the US National Health and Nutrition Survey from 2003 to 2018. The inflammatory potential of the diet was assessed by the DII score, and logistic regression was performed to evaluate the relationship between the DII score and the development of hyperuricemia; subgroup analyses were used to discuss the influence of other factors on the relationship.

Results

Participants in the other quartiles had an increased risk of hyperuricemia compared to those in the lowest quartile of DII scores. Stratification analyses stratified by body mass index (BMI), sex, hypertension, drinking, diabetes, education level and albumin-creatinine-ratio (ACR) revealed that the DII score was also associated with the risk of hyperuricemia (P<0.05). There was an interaction in subgroup analysis stratified by sex, age, and hypertension (P for interaction <0.05). The results showed a linear-like relationship between DII and hyperuricemia, with a relatively low risk of developing hyperuricemia at lower DII scores and an increased risk of developing hyperuricemia as DII scores increased.

Conclusions

This study showed that the risk of hyperuricemia increased at slightly higher DII scores (i.e., with pro-inflammatory diets), but not significantly at lower levels (i.e., with anti-inflammatory diets). The contribution of the DII score to the development of hyperuricemia increased with higher scores. The relationship between inflammatory diets and hyperuricemia requires more research on inflammation, and this study alerts the public that pro-inflammatory diets may increase the risk of developing hyperuricemia.

Uric Acid Inhibits Mice Pancreatic Steatosis via the Glycerophospholipid Pathway

Background: despite evidence for mutually reinforcing effects of serum uric acid (SUA) and lipids, the effects of uric levels on pancreatic steatosis are not well-established. In this study, the relationship between low concentrations of uric acid and pancreatic steatosis was evaluated. Methods: forty C57BL/6J mice were fed a diet of high uric acid (HU), high fat (HF), high uric acid and high fat (HUHF), and normal control (NC) (10 mice in each group). Weight was measured weekly. Ultrasonography was performed to observe the pancreatic echo intensity of all mice before the end of feeding. Subsequently, peripheral blood was taken for biochemical examination. Intact pancreatic tissues were taken, part of which was used for pathological examination, part of which was used for PCR experiments and Western Blot experiments to obtain glycerophospholipid-associated mRNA data and protein levels. Results: body weight was significantly higher in the HF group than in the other three groups. Higher uric acid matched lower total cholesterol and triglyceride, matched higher low-density lipoprotein, and matched equal high-density lipoprotein. Ultrasound images and HE staining of pancreatic tissues of mice showed that higher uric acid matched lower fat content. The mRNA levels of phospholipase A2 group IB were highest in high uric acid group, while relative protein expression levels were lowest in high uric acid and control groups. Phospholipase A2 group IIA showed the opposite patterns. Conclusions: elevated serum uric acid at low concentrations can inhibit pancreatic steatosis, which is modulated via the glycerophospholipid metabolic pathway.

Design of Machine Learning Algorithms and Internal Validation of a Kidney Risk Prediction Model for Type 2 Diabetes Mellitus

Objective

This study aimed to explore specific biochemical indicators and construct a risk prediction model for diabetic kidney disease (DKD) in patients with type 2 diabetes (T2D).

Methods

This study included 234 T2D patients, of whom 166 had DKD, at the First Hospital of Jilin University from January 2021 to July 2022. Clinical characteristics, such as age, gender, and typical hematological parameters, were collected and used for modeling. Five machine learning algorithms [Extreme Gradient Boosting (XGBoost), Gradient Boosting Machine (GBM), Support Vector Machine (SVM), Logistic Regression (LR), and Random Forest (RF)] were used to identify critical clinical and pathological features and to build a risk prediction model for DKD. Additionally, clinical data from 70 patients (nT2D = 20, nDKD = 50) were collected for external validation from the Third Hospital of Jilin University.

Results

The RF algorithm demonstrated the best performance in predicting progression to DKD, identifying five major indicators: estimated glomerular filtration rate (eGFR), glycated albumin (GA), Uric acid, HbA1c, and Zinc (Zn). The prediction model showed sufficient predictive accuracy with area under the curve (AUC) values of 0.960 (95% CI: 0.936-0.984) and 0.9326 (95% CI: 0.8747-0.9885) in the internal validation set and external validation set, respectively. The diagnostic efficacy of the RF model (AUC = 0.960) was significantly higher than each of the five features screened with the highest feature importance in the RF model.

Conclusion

The online DKD risk prediction model constructed using the RF algorithm was selected based on its strong performance in the internal validation.

Prevalence and Risk Factors of Hyperuricemia Among Young and Middle-Aged Tibetan Men Living at Ultrahigh Altitudes: A Cross-Sectional Study

He, Ben, Jiayue Feng, Yan Shu, Lichun Yang, Zepin He, Kanxiu Liao, Hui Zhuo, and Hui Li. Prevalence and risk factors of hyperuricemia among young and middle-aged Tibetan men living at ultrahigh altitudes: a cross-sectional study. High Alt Med Biol. 25:42-48, 2024. Background: Few studies have examined the prevalence or risk factors of hyperuricemia among populations living at ultrahigh altitudes. Here we examined the prevalence of hyperuricemia and factors associated with it among young and middle-aged Tibetan men living at ultrahigh altitudes. Methods: This cross-sectional study analyzed 672 Tibetan men 18-60 years old living on the Qinghai-Tibet Plateau (mean altitude 4,014 m) within the county of Litang in the Ganzi Tibetan autonomous prefecture of Sichuan Province, China. Demographic and clinical data were collected from self-administered questionnaires, physical examinations and laboratory tests. Participants whose blood uric acid (UA) contained >420 μmol/l were classified as having hyperuricemia. Results: Of the 672 men analyzed, 332 (49.4%) had hyperuricemia. Multivariate logistic regression showed risk of hyperuricemia to correlate positively with body mass index (per 1 U increase: odds ratio [OR] 1.172, 95% confidence interval [CI] 1.1066-1.243), triglycerides (OR 1.408, 95% CI 1.084-1.828), red blood cell count (OR 1.376, 95% CI 1.009-1.875), and creatinine level (per 1 U increase: OR 1.051, 95% CI 1.033-1.070). Conversely, risk of hyperuricemia correlated negatively with the presence of diabetes mellitus (OR 0.412, 95% CI 0.175-0.968). Subgroup analyses showed that prevalence of hyperuricemia was significantly higher among those with polycythemia than among those without it, and that UA levels correlated positively with hematocrit and hemoglobin levels. Conclusions: Hyperuricemia is an important public health problem among Tibetan men living at ultrahigh altitudes in Ganzi autonomous prefecture. The region urgently requires appropriate prevention and management efforts.

Is Environmental Cadmium Exposure Causally Related to Diabetes and Obesity?

Cadmium (Cd) is a pervasive toxic metal, present in most food types, cigarette smoke, and air. Most cells in the body will assimilate Cd, as its charge and ionic radius are similar to the essential metals, iron, zinc, and calcium (Fe, Zn, and Ca). Cd preferentially accumulates in the proximal tubular epithelium of the kidney, and is excreted in urine when these cells die. Thus, excretion of Cd reflects renal accumulation (body burden) and the current toxicity of Cd. The kidney is the only organ other than liver that produces and releases glucose into the circulation. Also, the kidney is responsible for filtration and the re-absorption of glucose. Cd is the least recognized diabetogenic substance although research performed in the 1980s demonstrated the diabetogenic effects of chronic oral Cd administration in neonatal rats. Approximately 10% of the global population are now living with diabetes and over 80% of these are overweight or obese. This association has fueled an intense search for any exogenous chemicals and lifestyle factors that could induce excessive weight gain. However, whilst epidemiological studies have clearly linked diabetes to Cd exposure, this appears to be independent of adiposity. This review highlights Cd exposure sources and levels associated with diabetes type 2 and the mechanisms by which Cd disrupts glucose metabolism. Special emphasis is on roles of the liver and kidney, and cellular stress responses and defenses, involving heme oxygenase-1 and -2 (HO-1 and HO-2). From heme degradation, both HO-1 and HO-2 release Fe, carbon monoxide, and a precursor substrate for producing a potent antioxidant, bilirubin. HO-2 appears to have also anti-diabetic and anti-obese actions. In old age, HO-2 deficient mice display a symptomatic spectrum of human diabetes, including hyperglycemia, insulin resistance, increased fat deposition, and hypertension.

The Management of Diabetes with Hyperuricemia: Can We Hit Two Birds with One Stone?

Serum urate (SU) is an independent predictor for the incidence of diabetes. In current diabetes treatment regimens, there is insufficient appreciation of the importance of hyperuricemia (HU) in disease control and prevention. To summarize the updated knowledge on the effects of SU on β-cell function, insulin resistance and chronic diabetic complications, as well as to evaluate the management of patients with both HU and diabetes, we searched the MEDLINE PubMed database, and included 285 journal articles. An inverted U-shaped relationship between fasting plasma glucose and SU levels was established in this review. Elevated SU levels may enhance the development of chronic diabetic complications, including macrovascular and microvascular dysfunction. Diet and exercise are essential parts of the lifestyle changes necessary for HU and diabetes management. Glucose- and urate-lowering drug selection and combination should be made with the principle of ameliorating, and at least not deteriorating, diabetes and HU. Medical artificial intelligence technology and monitoring systems can help to improve the effectiveness of long-term management of HU and diabetes through digital healthcare. This study comprehensively reviews and provides a scientific and reliable basis for and viewpoints on the clinical management of diabetes and HU.

Structural and functional integrity of endocrine pancreas post administration of Karwinskia humboldtiana fruit to Wistar rats: a possible therapeutic application for cancer of exocrine origin

AIMS

Pancreatic adenocarcinoma represents a therapeutic challenge due to the high toxicity of antineoplastic treatments and secondary effects of pancreatectomy. T-514, a toxin isolated from Karwinskia humboldtiana (Kh) has shown antineoplastic activity on cell lines. In acute intoxication with Kh, we reported apoptosis on the exocrine portion of pancreas. One of the mechanisms of antineoplastic agents is the induction of apoptosis, therefore our main objective was to evidence structural and functional integrity of the islets of Langerhans after the administration of Kh fruit in Wistar rats.

METHODS

TUNEL assay and immunolabelling against activated caspase-3 were used to detect apoptosis. Also, immunohistochemical tests were performed to search for glucagon and insulin. Serum amylase enzyme activity was also quantified as a molecular marker of pancreatic damage.

RESULTS

Evidence of toxicity on the exocrine portion, by positivity in the TUNEL assay and activated caspase-3, was found. On the contrary, the endocrine portion remained structurally and functionally intact, without apoptosis, and presenting positivity in the identification of glucagon and insulin.

CONCLUSIONS

These results demonstrated that Kh fruit induces selective toxicity on the exocrine portion and establish a precedent to evaluate T-514 as a potential treatment against pancreatic adenocarcinoma without affecting the islets of Langerhans.

Evaluation of levels of uric acid and lipid profile in hospitalized patients with diabetes

OBJECTIVE

Diabetes is the most common metabolic disorder that leads to various complications, and among these complications, disruption in the lipid profile and serum uric acid (SUA) is one of the significant cases that can lead to the deterioration of the health status of patients with diabetes. So, we aimed to evaluate the level of SUA and lipid profiles in patients with diabetes. A total of 230 patients with diabetes who were admitted to Razi Hospital, Rasht, Iran, were enrolled in this study. Demographical data and clinical characteristics of the patients include gender, body mass index (BMI), duration of diabetes, history of smoking, FBS, HbA1c, SUA, Creatinine (Cr), Cholesterol (Chol), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), retinopathy, hypertension, ischemic heart disease (IHD), and microalbuminuria were recorded. All data were analyzed using the SPSS version 21 by a significant level < 0.05.

RESULT

According to our results, 70 were male, and 160 were female, with a mean age of 57.36 ± 8.05 years and a mean BMI of 28.10 ± 4.62. The most frequent comorbidities were hypertension, 67%. The serum level of FBS, HBA1c, SUA, Cr, Chol, LDL, HDL, and TG were 191.47 ± 71.66 mg/dL, 7.94 ± 1.21 mg/dL, 5.65 ± 1.95 mg/dL, 0.94 ± 0.16 mg/dL, 167.28 ± 45.22 mg/dL, 95.91 ± 37.03 mg/dL, 39.78 ± 10.44 mg/dL, and 186.75 ± 76.65 mg/dL, respectively. Only UA had a significant relationship with TG level (P < 0.05).

Association between serum uric acid levels and cardiovascular risk factors among adults in India

BACKGROUND AND AIM

The objective of this study was to explore the association between serum uric acid (SUA) levels and cardiovascular risk factors in the Indian population.

METHODS AND RESULTS

This was a cross-sectional, population-based study. The study enrolled adults aged 20 years and above residing in rural, sub-urban, and urban. All participants completed a detailed questionnaire, underwent anthropometric measurements, and had blood samples collected. Participants were divided into three tertiles based on their SUA concentrations. A total of 2976 participants were included in this study, with 865 from rural, 1030 from sub-urban, and 1081 from urban populations. The mean values of cardiovascular risk factors were significantly higher in tertile 3 (p < 0.001) as compared to the other tertiles. However, we observed a negative trend between the increase of SUA and SUA/Scr ratio and HbA1c levels (Pearson correlation r = -0.068; p < 0.001 and r = -0.140; p < 0.001, respectively). The healthy and prediabetic groups did not show any significant change in HbA1c with increasing SUA levels, while an inverse trend was observed in diabetics. In the diabetic population, both men and women showed an inverse trend between increasing SUA levels and HbA1c in both known and newly diagnosed diabetes (p < 0.001).

CONCLUSIONS

The study found a positive association between SUA levels and cardiovascular risk factors. However, HbA1c was inversely correlated with increasing SUA tertiles in both known and newly diagnosed diabetes, as compared to the general population. Additionally, both men and women with diabetes consistently showed an inverse relationship between increasing SUA/SCr ratio and HbA1c levels.

The Effects of N-acetylcysteine on Transient Receptor Potential Melastatin 2 Channels Activation and Expression in Testicular Tissue of Diabetic Rats

INTRODUCTION

Diabetes mellitus (DM) is a common, chronic metabolic disease that has harmful effects on many diverse tissues, including the testis. One of the ways of tissue damage is the modification of transient receptor potential melastatin 2 (TRPM2) channels by increased reactive oxygen species (ROS). In our study for the first time, it was aimed to investigate TRPM2 channel activation in testicular tissues of diabetic rats induced by streptozotosin (STZ) and to examine the efficacy of N-acetylcysteine (NAC) treatment, which is an antioxidant.

METHODS

In our study, 28 Wistar albino male rats aged 8-10 weeks were used, and animals were divided into four groups: control group, NAC group, DM group, and DM + NAC group. The experimental phase was designed as eight weeks. The malondialdehyde (MDA) level, which is an indicator for lipid peroxidation due to oxidative stress, was measured by the spectrophotometric method. The Tunel assay was used to determine apoptosis on testicular tissue. TRPM2 immunoreactivity was determined by the avidin-biotin-peroxidase complex method, and quantitative polymerase chain reaction (QPCR) was used to determine TRPM2 expression levels.

RESULTS

It was seen that MDA levels were significantly increased in the DM group and decreased after NAC treatment. Similarly, it was observed that apoptosis levels, which increased significantly in diabetic rats, decreased to the levels of the control group after treatment. It was seen that TRPM2 activation and expression levels were significantly decreased in the DM group.

CONCLUSION

 The results of this study show that NAC regulates TRPM2 activation in the testicular tissue of patients with diabetes and has tissue-protective properties.

Mechanistic insights of soluble uric acid-induced insulin resistance: Insulin signaling and beyond

Hyperuricemia is a metabolic disease caused by purine nucleotide metabolism disorder. The prevalence of hyperuricemia is increasing worldwide, with a growing trend in the younger populations. Although numerous studies have indicated that hyperuricemia may be an independent risk factor for insulin resistance, the causal relationship between the two is controversial. There are few reviews, however, focusing on the relationship between uric acid (UA) and insulin resistance from experimental studies. In this review, we summarized the experimental models related to soluble UA-induced insulin resistance in pancreas and peripheral tissues, including skeletal muscles, adipose tissue, liver, heart/cardiomyocytes, vascular endothelial cells and macrophages. In addition, we summarized the research advances about the key mechanism of UA-induced insulin resistance. Moreover, we attempt to identify novel targets for the treatment of hyperuricemia-related insulin resistance. Lastly, we hope that the present review will encourage further researches to solve the chicken-and-egg dilemma between UA and insulin resistance, and provide strategies for the pathogenesis and treatment of hyperuricemia related metabolic diseases.

Estimation of health risks associated with dietary cadmium exposure

In much of the world, currently employed upper limits of tolerable intake and acceptable excretion of cadmium (Cd) (ECd/Ecr) are 0.83 µg/kg body weight/day and 5.24 µg/g creatinine, respectively. These figures were derived from a risk assessment model that interpreted β2-microglobulin (β2MG) excretion > 300 μg/g creatinine as a "critical" endpoint. However, current evidence suggests that Cd accumulation reduces glomerular filtration rate at values of ECd/Ecr much lower than 5.24 µg/g creatinine. Low ECd/Ecr has also been associated with increased risks of kidney disease, type 2 diabetes, osteoporosis, cancer, and other disorders. These associations have cast considerable doubt on conventional guidelines. The goals of this paper are to evaluate whether these guidelines are low enough to minimize associated health risks reliably, and indeed whether permissible intake of a cumulative toxin like Cd is a valid concept. We highlight sources and levels of Cd in the human diet and review absorption, distribution, kidney accumulation, and excretion of the metal. We present evidence for the following propositions: excreted Cd emanates from injured tubular epithelial cells of the kidney; Cd excretion is a manifestation of current tissue injury; reduction of present and future exposure to environmental Cd cannot mitigate injury in progress; and Cd excretion is optimally expressed as a function of creatinine clearance rather than creatinine excretion. We comprehensively review the adverse health effects of Cd and urine and blood Cd levels at which adverse effects have been observed. The cumulative nature of Cd toxicity and the susceptibility of multiple organs to toxicity at low body burdens raise serious doubt that guidelines concerning permissible intake of Cd can be meaningful.

Gender Difference in the Association of Hyperuricemia with Insulin Resistance and beta-cell Function in Nondiabetic Korean Adults: The 2019 Korea National Health and Nutrition Examination Survey

AIMS

This study was conducted to assess the association of uric acid (UA) with the homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-B) by gender in nondiabetic Korean adults.

MATERIALS AND METHODS

The study was carried out using data from the 2019 Korean National Health and Nutrition Examination Survey and included nondiabetic Korean men, premenopausal women, and postmenopausal women aged 20 years or older.

RESULTS

First, after adjusted for the related variables (excluding obesity), the prevalence of hyperuricemia (UA ≥ 7.0 mg/dL in men or UA ≥ 6.0 mg/dL in women) was positively associated with the quartiles of HOMA-IR and HOMA-B in men, premenopausal women, and postmenopausal women. Second, when further adjusted for obesity, hyperuricemia was positively associated with the quartiles of HOMA-IR and HOMA-B in men and postmenopausal women but not in premenopausal women. Third, after adjusted for the related variables (including obesity), UA level was positively associated with the quartiles of HOMA-IR and HOMA-B in men and postmenopausal women but not in premenopausal women.

CONCLUSIONS

hyperuricemia is positively associated with insulin resistance and beta-cell function in nondiabetic Korean men and postmenopausal women but not in premenopausal women.

Elevated serum uric acid is associated with cognitive improvement in older American adults: A large, population-based-analysis of the NHANES database

Background

The many studies revealing a connection between serum uric acid (SUA) and dementia have reported conflicting results. This study sought to investigate the relations between SUA and cognitive function in older adults.

Materials and methods

The sample was 2,767 American adults aged ≥60 years from the National Health and Nutrition Examination Survey 2011-2014. Cognitive performance was evaluated by the Consortium to Establish a Registry for Alzheimer's Disease test, animal fluency test, digit symbol substitution test, and composite z-score. Multivariate linear regression analyses were conducted to estimate the association between SUA and cognitive function.

Results

SUA level and cognitive function were significantly, positively correlated. Age significantly correlated with the association between SUA and cognitive function.

Conclusion

These findings support a connection between SUA and cognition, showing a positive link between SUA and cognitive scores among older American adults. We contend that a slight rise in uric acid within the normal range is advantageous for enhanced cognition. To confirm the precise dose-time-response relation, more tests will be needed.

Hyperuricaemia and its association with other risk factors for cardiovascular diseases: A population-based study

INTRODUCTION

Cardiovascular diseases are very common in the general population, and several factors play a role in their development. The purpose of this study was to investigate the relationship between hyperuricaemia and other cardiovascular disease risk factors.

METHODS

This cross-sectional study was conducted on 1008 people over the 15-year-old general population in Kerman, Iran. The blood samples of all patients were analysed for the uric acid serum level, and they completed a checklist including physical activity, previous history of hypertension and diabetes, smoking and opium.

RESULTS

A number of 1008 cases of people were entered into the study. According to the results of this study, 254 patients had uric acid levels above the 75th percentile (6 mg/dl in males, and 5 mg/dl in females). No significant difference was observed between gender (p = .249) and age groups (p = .125) of people with and without hyperuricaemia. The prevalence of overweight/obesity (p < .001), hypertension (p = .004) and low physical activity (p = .033) was significantly higher in patients with hyperuricaemia. The duration of hypertension was significantly higher in hyperuricaemic individuals (p = .022). Overweight/obesity (OR = 2.67; 95% CI = 1.87-3.82) and hypertension (OR = 1.40; 95% CI = 1.02-1.93) were two significant independent factors that contributed to the increased risk of hyperuricaemia in the subjects.

CONCLUSION

The uric acid serum level is higher in people with hypertension and overweight/obesity. Hyperuricaemia increases the risk of cardiovascular events, which can be prevented by determining the appropriate strategy for the early diagnosis and treatment of this metabolic disorder.

Quantification of uric acid concentration in tears by using PDMS inverse opal structure surface-enhanced Raman scattering substrates: Application in hyperuricemia

Hyperuricemia is closely related to a variety of diseases and has been listed as one of the twenty most persistent diseases in the 21st century by the United Nations. Therefore, strengthening the diagnosis of hyperuricemia has become imperative. Here, ordered inverse opal array structures (PAANs) composed of PDMS and gold nanoparticles (AuNPs) have been designed using a bottom-up self-assembly method. The structures exhibit a periodic distribution of hot spots, an enhancement factor (EF) of 4.22 × 10⁴, and a relative standard deviation (RSD) of signal intensity of less than 5%, which can provide high reproducibility of SERS signals. The PAANs substrate is used to detect uric acid in the tears of patients with hyperuricemia, and the limit of detection is 6.03 μM. The significant linear relationship between blood uric acid and tear uric acid indicates that the developed method is a rapid, effective, and non-invasive technique for the determination of uric acid in tears.

Lactobacillus paracasei X11 Ameliorates Hyperuricemia and Modulates Gut Microbiota in Mice

Hyperuricemia (HUA) is the presence of excessive uric acid (UA) in blood, which leads to an increased risk of chronic kidney disease and gout. Probiotics have the potential effect of alleviating HUA. The purpose of this study was to screen probiotics with UA-lowering activity and explore the underlying mechanism. The UA-lowering activity of 20 lactic acid bacteria strains was investigated in vitro, and the effect of candidate probiotics on UA metabolism was evaluated using the HUA Balb/c mouse model. The results showed that Lactobacillus paracasei X11 had excellent UA-lowering activity in vitro, which could degrade nucleotides and nucleosides completely within 30 min, and the degradation rates of purine and trioxypurine could reach 83.25% and 80.42%, respectively. In addition, oral administration of L. paracasei X11 could reduce serum UA by 52.45% and inhibit renal proinflammatory cytokine IL-1β by 50.69%, regulating adenosine deaminase (ADA), xanthine oxidase (XOD), and transporter expression (GLUT9, NPT1, and URAT1) to a normal level. Moreover, it could restore the ratio of Bacteroidetes to Firmicutes (Bac/Firm ratio) and showed a positive effect on the recovery of the intestinal microbiota. These findings provided fundamental information about the UA-lowering properties of probiotics, which suggested that L. paracasei X11 had the potential to be developed as a novel probiotic strain to ameliorate HUA.

Effect and Potential Mechanism of Lactobacillus plantarum Q7 on Hyperuricemia in vitro and in vivo

Hyperuricemia (HUA) is a disorder of purine metabolism resulting in abnormally elevated serum uric acid (UA) concentration. It is believed that there is an association between gut microbiota and HUA, and probiotics have the potential palliative effect. However, the underlying mechanism of probiotics in ameliorating HUA remains unclear. The purpose of this study was to investigate the effect and mechanism of Lactobacillus plantarum Q7 on HUA in Balb/c mice. The results showed that L. plantarum Q7 had an excellent capability to affect UA metabolism, which could degrade nucleotides by 99.97%, nucleosides by 99.15%, purine by 87.35%, and UA by 81.30%. It was observed that L. plantarum Q7 could downregulate serum UA, blood urea nitrogen (BUN), creatinine (Cr), and xanthine oxidase (XOD) by 47.24%, 14.59%, 54.59%, and 40.80%, respectively. Oral administration of L. plantarum Q7 could restore the liver, kidney, and intestinal injury induced by HUA and the expression of metabolic enzymes and transporters to normal level. 16S rRNA sequencing analysis showed that L. plantarum Q7 treatment could restore the imbalance of species diversity, richness, and community evenness compared with the model group. The ratio of Bacteroidetes to Firmicutes was recovered nearly to the normal level by L. plantarum Q7 intervention. The dominant microorganisms of L. plantarum Q7 group contained more anti-inflammatory bacteria than those of the model group. These findings indicated that L. plantarum Q7 might regulate UA metabolism and repair the liver and kidney injury by reshaping the gut microbiota and could be used as a potential probiotic strain to ameliorate HUA.

Association between circulating cystatin C and hyperuricemia: a cross-sectional study

INTRODUCTION/OBJECTIVES

Circulating cystatin C has reportedly been related to cardiovascular disease, diabetes, and metabolic syndrome, apart from its traditional role in estimating the glomerular filtration rate. However, whether circulating cystatin C is related to hyperuricemia remains unclear.

METHOD

We included 2406 men and 1273 women who attended their annual health checkups in this study. Anthropometric and biochemical parameters were measured. Hyperuricemia was diagnosed as fasting serum uric acid > 420 µmol/L in men and women.

RESULTS

A total of 695 (18.9%) participants were diagnosed with hyperuricemia. Hyperuricemic patients had significantly higher serum cystatin C levels than healthy controls (0.91 (0.83-1.02) versus 0.82 (0.72-0.92) mg/L, P < 0.001). Serum cystatin C levels were positively related to the prevalence of hyperuricemia, which was 5.18%, 14.76%, 22.66%, and 31.24% in participants with serum cystatin C levels in the first, second, third, and fourth quartiles, respectively (P < 0.001 for trend). In stepwise multivariate logistic regression analysis, participants with serum cystatin C in the fourth quartile had a more than twofold increased risk of hyperuricemia (OR 2.262, 95% CI 1.495-3.422; P < 0.001) compared with those with serum cystatin C in the first quartile. In subgroup analyses, the fourth quartile of cystatin C was related to increased risks of hyperuricemia in both non-obese and obese participants (OR 4.405, 95% CI 1.472-13.184, P = 0.008; OR 1.891, 95% CI 1.228-2.911, P = 0.004, respectively), in non-metabolic syndrome participants (OR 3.043, 95% CI 1.692-5.473; P < 0.001) but not in metabolic syndrome participants (OR 1.689, 95% CI 0.937-3.045; P = 0.081), and in non-non-alcoholic fatty liver disease (non-NAFLD) (OR 2.128, 95% CI 1.424-3.180; P < 0.001, respectively) and young and middle-aged participants (OR 2.235, 95% CI 1.492-3.348, P < 0.001) but not in NAFLD and elderly participants.

CONCLUSIONS

This study revealed a positive association of circulating cystatin C with hyperuricemia. Key Points • Serum cystatin C is associated with an increased risk of hyperuricemia. • Serum cystatin C is a useful biomarker in distinguishing patients at high risk of having hyperuricemia.

Effects of Sporisorium reiliana polysaccharides and Phoenix dactylifera monosaccharides on the gut microbiota and serum metabolism in mice with fructose-induced hyperuricemia

In recent decades, the prevalence of hyperuricemia has increased, and dietary fructose is an important risk factor for the development of this disease. This study investigated and compared the effects of Sphacelotheca reiliana polysaccharides and Phoenix dactylifera monosaccharides on a series of physiological and biochemical indicators and on the metagenomes and serum metabolites in mice with hyperuricemia caused by a high-fructose diet. S. reiliana polysaccharides inhibited uric acid biosynthesis and promoted uric acid excretion, thereby alleviating the hyperuricemia phenotype. In addition, hyperuricemia was closely related to the gut microbiota. After treatment with S. reiliana polysaccharides, the abundances of Bacteroidetes and Proteobacteria in the mouse intestines were decreased, the expression of genes involved in glycolysis/gluconeogenesis metabolic pathways and purine metabolism was downregulated, and the dysfunction of the gut microbiota was alleviated. With regard to serum metabolism, the abundance of hippuric acid, uridine, kynurenic acid, propionic acid and arachidonoyl decreased, and the abundances of serum metabolites in inflammatory pathways involved in kidney injury and gout, such as bile acid metabolism, purine metabolism and tryptophan metabolism pathways, decreased. P. dactylifera monosaccharides aggravated hyperuricemia. This research provides a valuable reference for the development of sugar applications.

Cyanidin-3-O-Glucoside Ameliorates Palmitic-Acid-Induced Pancreatic Beta Cell Dysfunction by Modulating CHOP-Mediated Endoplasmic Reticulum Stress Pathways

Cyanidin-3-O-glucoside (C3G) is a natural colorant with anti-diabetic properties, while its underlying mechanisms remain far from clear. Here, we investigated the protective role of C3G on palmitic acid (PA)-induced pancreatic beta cell dysfunction and further decipher its possible molecular mechanisms. Both primary isolated mouse islets and the INS-1E cell were used, and treated with a mixture of PA (0.5 mM) and C3G (12.5 µM, 25 µM, 50 µM) for different durations (12, 24, 48 h). We found that C3G could dose-dependently ameliorate beta cell secretory function and further alleviate cell apoptosis. Mechanistically, the primary role of the PKR-like ER kinase (PERK) endoplasmic reticulum (ER) stress pathway was detected by RNA sequencing, and the PERK-pathway-related protein expression, especially the pro-apoptotic marker C/EBP homologous protein (CHOP) expression, was significantly downregulated by C3G treatment. The critical role of CHOP in mediating the protective effect of C3G was further validated by small interfering RNA. Conclusively, C3G could ameliorate PA-induced pancreatic beta cell dysfunction targeting the CHOP-related ER stress pathway, which might be used as a nutritional intervention for the preservation of beta cell dysfunction in type 2 diabetes mellitus.

Mediating Effect of Body Mass Index and Dyslipidemia on the Relation of Uric Acid and Type 2 Diabetes: Results From China Health and Retirement Longitudinal Study

Objective

This study assessed temporal relationships of serum uric acid (SUA) with blood glucose and determine the mediating effects of body mass index (BMI) and dyslipidemia on the relation of SUA and risk of type 2 diabetes.

Methods

Participants aged ≥ 45 years were participated in 2011 and followed up until 2015. Cox proportional hazards regression with a robust variance estimator was performed to explore the association of SUA with the risk of diabetes, and crosslagged path analysis was introduced to examine the temporal relationships between SUA and blood glucose. A mediation analysis was finally used to identify the mediating effect of BMI and dyslipidemia on the relation of SUA and the future risk of diabetes.

Results

A total of 9,020 participants were included with an average age of 58.59 years at baseline in 2011, and 53.6% of them were women. Linear dose–response relationship was identified by restricted spline cubic analysis between baseline SUA and follow-up blood glucose (the non-linear trend for fasting plasma glucose (FPG): β2 = −0.71, p = 0.52; for HbA1c: β2 = 0.05, p = 0.07; for risk of diabetes: β2 = 0.12, p = 0.39). Additionally, compared with the lowest quartiles of SUA, the adjusted risk ratios of diabetes were 1.00 (95% CI: 0.82–1.23), 1.08 (95% CI: 0.89–1.31), and 1.37 (95% CI: 1.11–1.96) for quartile 2–4 (p-trend &lt; 0.01), respectively. Further additional adjustments for BMI or dyslipidemia, these ratios were not statistically significant. In addition, a unidirectional relationship from baseline SUA to follow-up FPG (ρ1 = 0.24, p = 0.03) was further confirmed using crosslagged path analysis. After stratifying by genders, the above results were only significant in the women subgroup, and we thus conducted a mediation analysis in women and found that the BMI and dyslipidemia partially mediated the effect of SUA on diabetes with a 23.05 and 18.82% mediating effect, respectively.

Conclusions

These findings provide strong evidence that hyperuricemia preceded diabetes, and the effect of baseline SUA on follow-up type 2 diabetes was more pronounced among middle-aged and elderly Chinese women, especially in postmenopausal women, and this effect is partly mediated by BMI and dyslipidemia at baseline.

Pharmacodynamic evaluation of the XOR inhibitor WN1703 in a model of chronic hyperuricemia in rats induced by yeast extract combined with potassium oxonate

Hyperuricemia is a common disease caused by a disorder of purine metabolism, which often causes hyperlipidemia and other metabolic diseases. WN1703 was demonstrated to be an effective xanthine oxidoreductase (XOR) inhibitor in our previous study. Here, we evaluated the pharmacodynamic effect of WN1703 on rats suffering from chronic hyperuricemia accompanied by disorders of lipid metabolism. We discovered that WN1703 was an efficacious uric acid (UA)-lowering compound. Simultaneously, it had effect on relieving renal injury, regulating lipid metabolism by reducing levels of triglycerides and low-density lipoprotein-cholesterol, increasing levels of high-density lipoprotein-cholesterol, and improving renal and liver lesions. WN1703 also exhibited anti-inflammatory and antioxidant activity by alleviating the increasing trend of levels of tumor necrosis factor-α, interleukin-1β, monocyte chemoattractant protein-1, and malondialdehyde, and improving the activity of superoxide dismutase and glutathione peroxidase. WN1703 appeared to be more effective than febuxostat in inhibiting XOR and had higher antioxidant activity. In general, the pharmacologic action of WN1703 showed a clear dose–effect relationship.

•

WN1703 showed similar effects on lowering UA and inhibiting XOR to febuxostat.

•

WN1703 could alleviate glucose and lipids metabolism disorder.

•

WN1703 could improve anti-inflammatory effects, and antioxidant effects.

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The pharmacologic action of WN1703 is dose-dependent.

Antihyperuricemic Effect of Green Alga Ulva lactuca Ulvan through Regulating Urate Transporters

A novel polysaccharide from Ulva lactuca (ULP) was purified using a Sepharose CL-4B column. Fourier transform infrared spectroscopy, high-performance liquid chromatography, and nuclear magnetic resonance spectroscopy were employed to analyze the structure of ULP. It consisted of rhamnose (Rha), glucuronic acid (GluA), galactose (Gal), and xylose (Xyl) at a molar ratio of 32.75:22.83:1.07:6.46 with the molecular weight of 2.24 × 10⁵ Da. The four major glycosidic residues found in ULP were →2,3)-α-l-Rhap-(1→, →4)-β-d-GlcpA-(1→, →2,6)-β-d-Galp-(1→, and →4)-β-d-Xylp-(1→. The antihyperuricemic activity of ULP was exhibited by detecting related biochemical indexes, urate transporter gene expressions, renal histopathology, and intestinal microbiota shifts. ULP obviously decreased the levels of serum uric acid (UA), blood urea nitrogen, and creatinine, while inhibited serum and hepatic xanthine oxidase activities as well as improved renal injury in hyperuricemic mice. Furthermore, the upregulation of UA excretion genes ABCG2/OAT1 and downregulation of UA resorption genes URAT1 and GLUT9 were detected. In addition, ULP exerted its antihyperuricemic effect through regulating the intestinal microbiome, characterized by elevating the helpful microbial abundance, meanwhile declining the harmful bacterial abundance and restoring the gut microbiome homeostasis. This study demonstrates the antihyperuricemic activity of ULP and its potential effect for the treatment of hyperuricemia-related diseases.

Hyperuricemia-induced endothelial insulin resistance: the nitric oxide connection

Hyperuricemia, defined as elevated serum concentrations of uric acid (UA) above 416 µmol L^-1, is related to the development of cardiometabolic disorders, probably via induction of endothelial dysfunction. Hyperuricemia causes endothelial dysfunction via induction of cell apoptosis, oxidative stress, and inflammation; however, it's interfering with insulin signaling and decreased endothelial nitric oxide (NO) availability, resulting in the development of endothelial insulin resistance, which seems to be a major underlying mechanism for hyperuricemia-induced endothelial dysfunction. Here, we elaborate on how hyperuricemia induces endothelial insulin resistance through the disruption of insulin-stimulated endothelial NO synthesis. High UA concentrations decrease insulin-induced NO synthesis within the endothelial cells by interfering with insulin signaling at either the receptor or post-receptor levels (i.e., proximal and distal steps). At the proximal post-receptor level, UA impairs the function of the insulin receptor substrate (IRS) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) in the insulin signaling pathway. At the distal level, high UA concentrations impair endothelial NO synthase (eNOS)-NO system by decreasing eNOS expression and activity as well as by direct inactivation of NO. Clinically, UA-induced endothelial insulin resistance is translated into impaired endothelial function, impaired NO-dependent vasodilation, and the development of systemic insulin resistance. UA-lowering drugs may improve endothelial function in subjects with hyperuricemia.

The Association of Serum Uric Acid with Beta-Cell Function and Insulin Resistance in Nondiabetic Individuals: A Cross-Sectional Study

PURPOSE

Higher serum levels of uric acid (SUA) are associated with an increased risk of developing type 2 diabetes. Meanwhile, insulin resistance and beta-cell dysfunction are critical factors that mediate the progression from normal glucose tolerance to impaired fasting glucose (IFG) and type 2 diabetes. We aimed to investigate the association between SUA levels and insulin resistance and beta-cell dysfunction in individuals without diabetes, thus explicating the role of uric acid in the early stage of the natural history of type 2 diabetes.

PATIENTS AND METHODS

We used cross-sectional data from the China Health and Nutrition Survey to examine the association. Insulin resistance and beta-cell dysfunction were estimated using the homeostasis model assessment of insulin resistance (HOMA-IR) index and homeostasis model assessment of beta-cell function (HOMA-beta) index, respectively. The associations were analyzed by using partial correlation analysis and multivariate logistic regressionl analysis.

RESULTS

SUA levels were positively associated with fasting glucose, fasting insulin, HOMA-IR in the total population. After adjustment for age, drinking, smoking, living area, daily dietary nutrient intake, body mass index (BMI), estimated glomerular filtration rate (eGFR), hypertension, and dyslipidemia, compared with participants in the lowest quartile of SUA, the adjusted odds ratios for the fourth quartiles were 1.56(1.09-2.24) for IFG, 1.51(1.27-1.78) for insulin resistance, and 1.06(0.88-1.27) for beta-cell dysfunction. In the subgroup analysis, no interactions were found between serum uric acid and age, drinking status, smoking status, BMI, hypertension, or dyslipidemia (all p for interaction>0.05).

CONCLUSION

In nondiabetic individuals, SUA levels are independently associated with IFG and insulin resistance, while no significant association exists between SUA and beta-cell dysfunction.

The application value of serum 25(OH)D3, uric acid, triglyceride, and homeostasis model assessment of insulin resistance in male patients with hyperuricemia combined with hypogonadism

BACKGROUND

The purpose of this study was to investigate the application value of serum 25(OH)D3, uric acid, triglyceride (TG), and homeostasis model assessment of insulin resistance (HOMA-IR) in male patients with hyperuricemia combined with hypogonadism.

METHODS

From August 2018 to August 2020, a total of 198 male patients with primary hyperuricemia were prospectively enrolled in our hospital for inpatient treatment in the department of Metabolism and Endocrinology. They are divided into normal gonadal function group (normal group, n = 117) and hypogonadal function group (hypogonadism group, n = 81), according to free testosterone (FT) level, International Index of Erectile Function (IIEF-5), and androgen deficiency in the aging male (ADAM) questionnaires. Laboratory indexes were compared between two groups. Multivariate logistic regression was applied to analyze the influencing factors of hypogonadism.

RESULTS

Among the 198 hyperuricemia patients, 40.91 % were hypogonadism. Compared with the normal group, the BMI, waist circumference (WC), and the prevalence of non-alcoholic fatty liver disease (NAFLD), hyperlipidemia (HLP), and obesity (OB) in the hypogonadism group were higher, and the difference was statistically significant (P < 0.05, respectively). The levels of fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), triacylglycerol (TG), serum uric acid (SUA), alanine transaminase (ALT) of hypogonadism group were higher than those of normal group, while the levels of TT, FT, E2, 25(OH)D3 of hypogonadism group were lower than those of normal group (P < 0.05, respectively). Pearson's linear correlation was used to analyze the correlation between the indicators with significant differences in general data and laboratory indicators and hypogonadism. BMI, WC, HOMA-IR, TG, SUA, TT, FT, 25(OH)D3, E2 were positively correlated with hypogonadism (r = 0.556, 0.139, 0.473, 0.143, 0.134, 0.462, 0.419, 0.572, 0.601, P = 0.012, 0.027, 0.018, 0.019, 0.028, 0.029, 0.030, 0.009, 0.003, respectively). Taking the above indicators as independent variables and hypogonadism as the dependent variable, logistic regression analysis found that the risk factors for hypogonadism were SUA, WC, BMI, HOMA-IR, TG, TT, FT, E2, and 25(OH) D3.

CONCLUSIONS

Serum 25(OH)D3, SUA, HOMA-IR, TG levels were positively correlated with male hyperuricemia patients with hypogonadism. They have important application value in the diagnosis of male hyperuricemia patients with hypogonadism.

Uric acid-induced pancreatic β-cell dysfunction

Hyperuricemia is associated with insulin resistance, pancreatic β-cell dysfunction and consequently with development of type 2 diabetes. Although a direct relationship between high levels of uric acid (UA) and the development of diabetes is still a controversial issue, there is some evidence that strongly points to pancreatic β-cells damage as a result of high serum UA levels. Here, the mechanisms underlying UA-induced β-cell damage are discussed. Available literature indicates that UA can decrease glucose-stimulated insulin secretion and cause β-cell death. The mechanisms underlying these effects are UA-induced oxidative stress and inflammation within the β-cells. UA also stimulates inducible nitric oxide (NO) synthase (iNOS) gene expression leading to NO-induced β-cell dysfunction. Thus hyperuricemia may potentially cause β-cell dysfunction, leading to diabetes. It may be hypothesized that in hyperuricemic subjects, UA-lowering drugs may be beneficial in preventing diabetes.

Effect modification of hyperlipidemia and hypertension on the association between type 2 diabetes and gout

AIMS

We evaluated the association between type 2 diabetes and gout by a retrospective cohort study.

METHODS

Data of 17,259 male and 18,318 female patients with type 2 diabetes were retrieved for the 1998-2010 period. These patients were matched to a comparison group (n=34,518 and n=36,636, respectively) in a 1:2 ratio by age and region.

RESULTS

We found that patients with type 2 diabetes after adjustment for hyperlipidemia and hypertension had a lower risk of incident gout than the matched population (incidence rate ratio, men: 0.39 [95% CI: 0.36-0.42]; women: 0.78 [0.72-0.84]). Specifically, type 2 diabetes alone without hyperlipidemia and hypertension was associated with a reduced risk of incident gout in men (adjusted relative risk [RR]: 0.29, 95% CI: 0.22-0.39), but not in women (0.86, 95% CI: 0.55-1.36). We found that insulin users with hyperlipidemia and hypertension associated with risk of incident gout and no sex-specific differences were noted (adjusted RR, men: 1.28 [95% CI: 1.11-1.48]; women: 1.32 [95% CI: 1.14-1.53]). Specifically, insulin users alone without hyperlipidemia and hypertension were not statistically significantly associated with gout risk (P≥.0954).

CONCLUSIONS

The results of this study indicated that hyperlipidemia and hypertension modified the association between type 2 diabetes and gout.

Uric Acid and Cardiovascular Disease: An Update From Molecular Mechanism to Clinical Perspective

Uric acid (UA) is the end product of purine nucleotide metabolism in the human body. Hyperuricemia is an abnormally high level of UA in the blood and may result in arthritis and gout. The prevalence of hyperuricemia has been increasing globally. Epidemiological studies have shown that UA levels are positively correlated with cardiovascular diseases, including hypertension, atherosclerosis, atrial fibrillation (AF), and heart failure (HF). Hyperuricemia promotes the occurrence and development of cardiovascular diseases by regulating molecular signals, such as inflammatory response, oxidative stress, insulin resistance/diabetes, endoplasmic reticulum stress, and endothelial dysfunction. Despite extensive research, the underlying molecular mechanisms are still unclear. Allopurinol, a xanthine oxidase (XO) inhibitor, has been shown to improve cardiovascular outcomes in patients with HF, coronary heart disease (CHD), type 2 diabetes (T2D), and left ventricular hypertrophy (LVH). Whether febuxostat, another XO inhibitor, can improve cardiovascular outcomes as well as allopurinol remains controversial. Furthermore, it is also not clear whether UA-lowering treatment (ULT) can benefit patients with asymptomatic hyperuricemia. In this review, we focus on the latest cellular and molecular findings of cardiovascular disease associated with hyperuricemia and clinical data about the efficacy of ULT in patients with cardiovascular disease.