Uric acid secretion from adipose tissue and its increase in obesity

The role of the estimated glomerular filtration rate and body roundness index in the risk assessment of uric acid-lowering therapy-resistant gout in U.S. adults: evidence from the National Health and Nutrition Examination Survey (2007-2018)

OBJECTIVE

To explore the risk factors for uric acid-lowering therapy-resistant gout (UALT-RG) and its relationships with the estimated glomerular filtration rate (eGFR), body roundness index (BRI), and visceral adiposity index (VAI) via 2007-2018 National Health and Nutrition Examination Survey (NHANES) data.

METHODS

We calculated the BRI using waist circumference and standing height; the VAI using triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and body mass index (BMI); and the eGFR from serum creatinine levels. We also collected gout data. We explored the relationships of the eGFR, BRI, and VAI with UALT-RG risk via univariable and multivariable weighted logistic regression, trend analysis, and restricted cubic splines.

RESULTS

Among the 1,811 patients with gout, ∼9.08% had UALT-RG; these patients were more likely to have obesity, comorbid diabetes (36% [27-47%] vs. 25% [22-28%]) or impaired kidney function (eGFR < 60 mL/min/1.73 m2, 34.5% [27-43%] vs. 22.5% [20-26%]); be former smokers; and take colchicine (10% [5.6-19%] vs. 4.3% [2.8-6.7%]). Logistic regression and trend analysis suggested that an elevated BRI and decreased eGFR were independent risk factors and potential screening indicators for UALT-RG. Restricted cubic spline analysis revealed a negative linear trend between the eGFR and UALT-RG risk (p-overall < 0.0001) and a significant positive correlation between the BRI and UALT-RG risk (p-overall < 0.0001).

CONCLUSION

An increased BRI and decreased eGFR may be independent risk factors and assessment indicators for UALT-RG in U.S. adults. It is necessary to monitor serum urate levels more closely and conduct early multidisciplinary comanagement when gout is comorbid with visceral obesity and chronic kidney disease stages 3-5.

Adipocyte-secreted ANGPTL2 promotes hyperuricemia through inhibiting AKT/ABCG2 signaling

AIMS

Overweight and obesity are closely associated with hyperuricemia (HUA). However, the effect of obesity-induced adipokine on the level of serum uric acid (UA) has not been fully elucidated. This study aimed to determine the role of adipokine in the pathogenesis of HUA.

METHODS

Omental adipose tissues from HUA patients with obesity were collected for data-independent acquisition (DIA) proteomics analysis, and the secreted protein angiopoietin-like protein (ANGPTL2) was identified and further validated via Western blot and ELISA. Angptl2 knockout (ko) and adipocyte-specific ANGPTL2 overexpression mice were generated to establish HUA models. HK2 cells and primary renal tubule epithelial cells (RTECs) were applied to induce HUA cell model and treated with recombinant human ANGPTL2 or supernatants derived from C3H10 cells differentiated into adipocytes.

RESULT

ANGPTL2 levels were significantly elevated in the omental adipose tissue from HUA with obesity patients compared to control participants. Circulating ANGPTL2 levels were also increased, and positively correlated with serum UA levels, especially in male participants. Plasma UA levels were significantly decreased in Angptl2 ko mice, coinciding with up-regulated expression of ATP binding cassette subfamily G member 2 (ABCG2) and down-regulated glucose transporter 9 (GLUT9) in renal tissue. However, plasma UA levels were significantly increased, accompanied by decreased ABCG2 expression and enhanced GLUT9 expression after adipocyte-specific ANGPTL2 overexpression. Furthermore, adipocyte-derived ANGPTL2 increased UA level in cell supernatants through the inhibition of protein kinase B (AKT)/ABCG2 signaling in RTECs and HK2 cells.

CONCLUSION

Adipokine ANGPTL2 levels were significantly elevated in HUA patients with obesity. Circulating ANGPTL2 concentrations were independently associated with serum UA levels, particularly in obese males. Adipocyte-secreted ANGPTL2 promoted the level of UA through AKT/ABCG2 signaling in renal tubular cells. These findings establish ANGPTL2 as a critical adipokine linking obesity to hyperuricemia and suggest its potential as a novel therapeutic target for HUA.

Obesity reduces the urate-lowering efficacy among patients with primary gout: a prospective cohort study

OBJECTIVES

Obesity affects 53% of gout patients, while its effect on urate-lowering therapy (ULT) is unclear. This study aimed to compare the response to febuxostat among different BMI catalogs of male gout patients.

METHODS

A prospective study recruited 633 men with gout, classified by BMI into normal-weight, overweight and obese groups. Baseline age, disease duration and serum urate (SU) levels were matched simultaneously. All participants received febuxostat for 12 weeks, increasing the dosage from 20 to 40 mg daily. We compared the efficacy of ULT and the incidence of gout flares in three groups. Cox regression analysis was used to identify risk factors for achieving target SU levels before and after matching. Restricted cubic spline (RCS) curves were used to illustrate the relationship between BMI and hazard ratio (HR) for SU achievement.

RESULTS

The proportion of participants achieving SU < 6.0 mg/dl in the obese group was 38.9%, significantly lower than the overweight (54.2%) and normal-weight groups (63.8%) (P < 0.05), with no significant difference between the overweight and normal-weight groups at week 12. High BMI (HR = 0.92, 95% CI 0.89-0.96, P < 0.001) independently prevented achieving the SU target, with a similar effect after matching. Obese and overweight individuals had a higher cumulative incidence of gout flares compared with the normal-weight group (P < 0.05). The linear relationship between BMI and HR for achieving the SU target was suggested by RCS (nonlinear P > 0.05).

CONCLUSION

Obesity significantly reduces the efficacy of febuxostat-based ULT in male gout patients rather than being overweight.

TRIAL REGISTRATION

China Clinical Trial Registry, #ChiCTR2300078804.

Microbe-dependent and independent effects of diet on metabolic inflammation in glucose metabolism regulation

Diet can contribute to the development of metabolic disease including type 2 diabetes (T2D) by inducing metabolic inflammation. While the gut microbiota mediates the effects of diet, the diet can also exert its effects independent of gut microbes. The microbe-dependent and -independent effects of diet on inflammation remain to be elucidated. This review examines recent advances and dissects the specifics of both gut microbe-dependent and independent mechanisms through which diet impacts inflammation and glucose metabolism. We delineate how diet interacts with the gut microbiome and induces metabolic inflammation. We also describe the direct effects of dietary components and their related metabolites on the immune system, and explore how diet-induced sterile inflammation may contribute to metabolic disorders. It is important to consider both microbe-dependent and independent pathways when developing therapeutic approaches aimed at preventing T2D.

Gene-environment interaction modifies the association between hyperinsulinemia and serum urate levels through SLC22A12

BACKGROUNDHyperinsulinemia and insulin resistance often accompany elevated serum urate levels (hyperuricemia), a highly heritable condition that triggers gout; however, the underlying mechanisms are unclear.METHODSWe evaluated the association between the index of hyperinsulinemia and the fractional excretion of urate (FEUA) in 162 outpatients. The underlying mechanisms were investigated through single-cell data analysis and kinase screening combined with cell culture experiments. In 377,358 participants of the UK Biobank (UKBB), we analyzed serum urate, hyperinsulinemia, and salt intake. We also examined gene-environment interactions using single nucleotide variants in SLC22A12, which encodes urate transporter 1 (URAT1).RESULTSThe index of hyperinsulinemia was inversely associated with FEUA independently of other covariates. Mechanistically, URAT1 cell-surface abundance and urate transport activity were regulated by URAT1-Thr408 phosphorylation, which was stimulated by hyperinsulinemia via AKT. Kinase screening and single-cell data analysis revealed that serum and glucocorticoid-regulated kinase 1 (SGK1), induced by high salt, activated the same pathway, increasing URAT1. Arg405 was essential for these kinases to phosphorylate URAT1-Thr408. In UKBB participants, hyperinsulinemia and high salt intake were independently associated with increased serum urate levels. We found that SLC22A12 expression quantitative trait locus (eQTL) rs475688 synergistically enhanced the positive association between serum urate and hyperinsulinemia.CONCLUSIONURAT1 mediates the association between hyperinsulinemia and hyperuricemia. Our data provide evidence for the role of gene-environment interactions in determining serum urate levels, paving the way for personalized management of hyperuricemia.FUNDINGACRO Research Grants of Teikyo University; Japan Society for the Promotion of Science; the Japanese Society of Gout and Uric & Nucleic Acids; Fuji Yakuhin; Nanken-Kyoten; Medical Research Center Initiative for High Depth Omics.

HepG2 cells do not express xanthine oxidoreductase (XOR): Implications for XOR and uric acid-related research

Although the relative extent of xanthine oxidoreductase (XOR) varies considerably in human tissues, the greatest specific activity is reported in the liver and intestines. Unlike murine models, where primary hepatocytes are readily available, human counterparts are not. As such, investigators often utilize the human carcinoma cell line HepG2 for in vitro experimentation as these cells proliferate well in culture medium. Some of the studies using HepG2 cells for proof-of-principal experimentation focus on uric acid (UA) and/or XOR activity. However, it has been reported that hepatocellular carcinoma diminishes XOR expression to nearly unmeasurable levels when compared to normal cell counterparts which posits the question of validity in the context of using HepG2 cells for XOR/UA assessments. As such, we closely examined XOR expression, protein abundance, and enzymatic activity in HepG2 cells and compared these results to an immortalized murine hepatocyte line (AML12) as well as murine liver homogenate. We report the absence of detectable XOR message, protein, and enzymatic activity in HepG2 cells. Since cellular XOR expression has been reported to be stimulated by hypoxia and serum starvation, we then exposed both AML12 and HepG2 cells to hypoxia (1% O2) for 24 h or serum starvation which impacted XOR activity in AML12 cells, but not in HepG2 cells. Knowing that several studies report XOR activity in HepG2 cells, we compared a commonly used non-selective XOR assay kit to our sensitive and selective HPLC/electrochemical assay. The kit assay indicated XOR activity in HepG2 cells; however, XOR inhibition did not diminish this activity. To account for alternative enzymatic oxidization of hypo/xanthine to UA, we investigated HepG2 cells for aldehyde oxidase (AO) abundance and found immunodetectable AO protein as well as AO-inhibitable conversion of hypoxanthine to UA; albeit, at a much slower rate when compared to XOR. In toto, these data confirm that HepG2 cells do not demonstrate XOR activity and thus commonly used kit assays for XOR, in the absence of XOR inhibitor controls, may indicate a positive response induced by an alternative source of peroxide and UA such as AO.

Impact of body mass index on the association between kidney function and insulin resistance in diabetic and nondiabetic populations

AIMS/INTRODUCTION

The kidneys play a role in regulating insulin metabolism, and kidney function may indicate the progression to insulin resistance (IR) in individuals with obesity and diabetes. We evaluated the relationship between kidney function biomarkers and IR in diabetic and nondiabetic adults categorized by body mass index (BMI).

METHODS

A total of 8,272 adults from the China Health and Nutrition Survey 2009 were categorized into four groups based on BMI (overweight/obesity vs underweight/normal weight) and diabetes status (diabetes vs non-diabetes). Univariable and multivariable linear regression, along with restricted cubic spline regression, were used to determine the relationship between estimated glomerular filtration rate (eGFR), creatinine, urea nitrogen, uric acid (UA), and homeostasis model assessment for insulin resistance (HOMA-IR).

RESULTS

The relationship between kidney function biomarkers and IR only existed in the overweight/obese populations and varied by diabetic status. In diabetic patients, linear associations were observed: eGFR was negatively associated with HOMA-IR, and creatinine was positively associated. In nondiabetic individuals, nonlinear associations were found. The relationship between eGFR and HOMA-IR followed an L-shaped curve: HOMA-IR decreased as eGFR increased up to 100 mL/min/1.73 m2, then slightly increased. The UA-HOMA-IR association showed an inverted L-shape: HOMA-IR increased with higher UA levels, plateauing after UA exceeded 360 μmol/L.

CONCLUSIONS

Kidney function biomarkers are associated with IR in overweight/obese populations, with and without diabetes. eGFR and creatinine can be indicators of IR in overweight/obese subjects with diabetes, while eGFR and UA may be used in those without diabetes.

Non-linear association between visceral adipose tissue area and serum uric acid concentration in US adults: findings from NHANES 2011-2018

BACKGROUND

Research on the relationship between visceral adipose tissue (VAT) and serum uric acid (SUA) in the general population remains limited. This study aims to comprehensively examine the association between VAT area and SUA concentrations in a representative sample of U.S. adults.

METHODS

Data were drawn from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2018. A total of 10,514 participants aged 18 to 59 years were included in the analysis. VAT area was measured using dual-energy X-ray absorptiometry (DXA) scans, and SUA levels were collected at mobile examination centers. Multivariable linear regression models were employed to assess the association between VAT and SUA. Restricted cubic splines (RCS) were used to detect potential non-linear relationships. Subgroup analyses were conducted based on age, sex, drinking status, and renal function to test the robustness of the findings.

RESULTS

The median VAT area and SUA concentration were 91.24 cm² and 5.2 mg/dL, respectively. In the unadjusted model, each standard deviation (SD) increase in VAT was positively associated with SUA (β = 0.43; 95% CI: 0.39-0.47). After adjusting for covariates, this positive association remained consistent across all models. RCS analysis revealed a non-linear relationship (P for non-linearity < 0.001), with a stronger association observed when VAT was below 3.3 SDs. Significant interactions were identified in age and sex subgroups (P for interaction < 0.05).

CONCLUSION

This study demonstrates a positive, non-linear association between VAT area and SUA concentrations in young and middle-aged U.S. adults. The observed threshold effect provides valuable insight for clinicians in stratifying risks for hyperuricemia and related comorbidities, particularly among individuals with elevated VAT levels.

Association of Chronic Kidney Disease With Increased Glucose Uptake-Associated Metabolic Activity of Visceral Adipose and Subcutaneous Adipose Tissue in Patients With Gout

OBJECTIVE

We evaluate the 18F-fluorodeoxyglucose positron emission tomography (PET) standardized uptake value (SUV) by PET/computed tomography (CT) scans in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in patients with and without gout. Additionally, we investigate whether glucose uptake in these tissues predicts the progression of chronic kidney disease (CKD).

METHODS

We used International Classification of Diseases, Tenth Revision codes from the University of California San Diego patient database to identify patients with gout and controls, forming a cohort of individuals who underwent PET/CT scans. The mean VAT and SAT maximum SUV (SUVmax) were measured using PET/CT scans and adjusted for potential confounders using inverse probability of weighting analysis. We also employed multivariable linear regression to analyze changes in estimated glomerular filtration rate (eGFR) after PET/CT scans.

RESULTS

The study included 221 patients, with 120 diagnosed with gout. After the inverse probability of weighting adjustment, the mean VAT and SAT SUVmax were higher in patients with gout (mean VAT SUVmax: β = 0.09, 95% confidence interval [CI] 0.04-0.15; mean SAT SUVmax: β = 0.06, 95% CI 0.01-0.12). Additionally, in patients with gout with CKD stage ≥3, higher mean VAT and SAT SUVmax were associated with decreased eGFR in the 5 years following PET/CT scans (mean VAT SUVmax: β = -1.76, 95% CI -3.50 to -0.01; mean SAT SUVmax: β = -2.97, 95% CI -5.61 to -0.32).

CONCLUSION

Elevated glucose uptake-associated metabolic activity in both VAT and SAT was observed in patients with gout, which may contribute to CKD progression among patients with both gout and CKD.

Lifestyle and Biochemical Parameters That May Hamper Immune Responses in Pediatric Patients After Immunization with the BNT162b2 mRNA COVID-19 Vaccine

BACKGROUND

The aim of this study was to evaluate whether increased body mass index (BMI) and biochemical and lifestyle parameters linked to obesity and smoke exposure disrupt immune responses of children and adolescents following vaccination with the mRNA BNT162b2 vaccine.

METHODS

A prospective, single-center, cohort study was conducted. Participants were assigned to receive two doses of the mRNA vaccine. Anti-SARS-CoV-2 IgG and neutralizing antibodies (AB) were measured before vaccination (T0) and 14 days after the second dose (T1). BMI and biochemical parameters were evaluated at T0. A questionnaire on lifestyle characteristics was filled in.

RESULTS

IgG optical density (OD) ratio at T1 was lower in the overweight-obese group regardless of COVID-19 disease positive history [p = 0.028 for the seronegative group, p = 0.032 for the seropositive group]. Neutralizing AB were lower in overweight-obese participants in the seronegative group at T1 [p = 0.008]. HDL, fasting glucose/insulin ratio (FGIR), C-reactive protein (CRP), HBA1c, uric acid, and smoke exposure were significantly correlated with BMI [p = 0.006, p < 0.001, p < 0.001, p = 0.006, p = 0.009, p < 0.001, respectively]. The main biochemical parameters that were inversely correlated with IgG and neutralizing AB titers at T1 were uric acid [p = 0.018, p = 0.002], FGIR [p = 0.001, p = 0.008] and HBA1C [p = 0.027, p = 0.038], while smoke exposure negatively affected the humoral immune responses at T0 in the convalescent group [p = 0.004, p = 0.005].

CONCLUSIONS

Current data suggests that uric acid, insulin resistance (IR), and smoke exposure could adversely affect the immune responses in overweight-obese vaccinated children, highlighting the need for actions to enhance the protection of this particular subgroup.

The Regulatory Effects of Exercise and Metformin on Biomarkers in Obesity: A Focus on Uric Acid, Irisin, Adiponutrin, Adropin, and Copeptin

Background and Objectives: Obesity has become one of the most significant health problems nowadays, with its prevalence rapidly increasing. Approaches such as diet and exercise play an important role in the treatment of obesity. This study aimed to investigate the responses of uric acid, irisin, adiponutrin, adropin, and copeptin levels to exercise and metformin intervention in obesity. Materials and Methods: Thirty-six male Sprague-Dawley rats were randomly divided into seven groups: healthy control (HC), sham (S), obese control (OC), metformin (M), exercise (E), metformin + exercise (ME), and decapitation (D). After obesity was induced through a 12-week high-fat diet, obese rats underwent a 4-week aerobic exercise and metformin intervention. Results: Uric acid, irisin, adiponutrin, adropin, and copeptin levels were determined using an ELISA method. Copeptin levels significantly decreased in the ME group (p < 0.001). Irisin levels significantly increased in the E and ME groups (p < 0.001). The most notable increases in adropin levels occurred in the E and ME groups (p < 0.001). Uric acid levels were highest in the OC group but significantly lower in the E and M groups (p < 0.001). Adiponutrin levels did not change in response to exercise or metformin intervention in obesity (p > 0.05). Conclusions: These findings suggest that exercise and metformin intervention may play an effective role in obesity management.

Association between RC/HDL-C and hyperuricemia in adults: evidence from NHANES 2005-2018

Background

The incidence of hyperuricemia is growing in the world, with a significant influence on the survival and healthy condition of the patient. The connection between serum residual cholesterol (RC) to high-density lipoprotein cholesterol (HDL-C) ratio and hyperuricemia is uncertain. Consequently, we tried to elucidate the connection between the hyperuricemia and RC/HDL-C ratio.

Methods

Based on the National Health and Nutrition Examination Survey (NHANES) database, data from 2005 to 2018 were utilized in this cross-sectional research. RC/HDL-C index was calculated by (TC - HDL-C - LDL-C)/HDL-C. Participants were diagnosed with hyperuricemia when the serum uric acid concentration reached 6 mg/dL in women and 7 mg/dL in men. Our researcher utilized smoothed curve fitting and multivariate logistic regression analysis to examine between RC/HDL-C and hyperuricemia among adults. The consistency of these results was examined in various population subgroups.

Results

2376 individuals (19.1%) were stratified into the hyperuricemia group. We observed statistically significant differences (P values < 0.05) in the hyperuricemia population for remaining variables, except for economic level and alcohol drinking. After correcting for potential confounders, our researchers discovered the strong positive connection between the RC/HDL-C and the possibility of incurring hyperuricemia. The incidence of RC/HDL-C elevated by 98% with each additional unit of the RC/HDL-C. Subgroup analyses showed correlations for the majority of subgroups remained stable. However, gender and several diseases may modify this association.

Conclusions

Higher RC/HDL-C is correlated with higher prevalence rate of developing hyperuricemia. However, further research is still required to confirm the causal association.

Association between mixed venous oxygen saturation and serum uric acid levels in patients with heart failure

Hypoxia leads to increased purine metabolism in tissues, resulting in increased serum uric acid levels, and may also cause impaired uric acid excretion in the kidneys and intestinal tract. However, the relationship between hypoxia and serum uric acid levels in patients with heart failure remains largely unexplored. Because mixed venous oxygen saturation is an acute indicator of systemic oxygenation, in this study, we investigated the relationship between mixed venous oxygen saturation and serum uric acid levels. This retrospective analysis included 386 patients with heart failure who underwent cardiac catheterization at our institution. The relationship between mixed venous oxygen saturation and serum uric acid levels was examined by single regression analysis. Stratified regression analysis, structural equation modeling, and partial correlation analysis were used to examine the effects of eight factors known to influence mixed venous oxygen saturation and serum uric acid levels. The single regression analysis showed a significant negative correlation between mixed venous oxygen saturation and serum uric acid levels (P<0.001). Significant negative correlations were also observed in many subgroups in the stratified analysis, in the path diagram based on structural equation modeling, and in the partial correlation analysis. These results suggest that there may be a direct relationship between mixed venous oxygen saturation and serum uric acid levels that is not mediated by any known factor.

Rumenomics: Evaluation of rumen metabolites from healthy sheep identifies differentially produced metabolites across sex, age, and weight

Background

The rumen harbors a diverse and dynamic microbiome vital in digesting vegetation into metabolic byproducts for energy and general biological function. Although previous studies have reported connections between the rumen and the overall health of the sheep, the exact biological process by which this occurs is not well understood. Therefore, our study aimed to quantify sheep rumen metabolites to determine if enriched biological pathways are differentiable across phenotypic features of sex, age, and weight.

Results

We collected and quantified metabolites of rumen samples from sixteen sheep using liquid chromatography-tandem mass spectrometry. We performed a series of univariate and multivariate statistical analyses to interpret the rumen metabolomics data. To identify metabolic pathways associated with the phenotypic features of sex, weight, and age, we used MetaboAnalyst, which identified amino acid metabolism as a distinguishing factor. Among the pathways, phenylalanine metabolism emerged as a key pathway differentiating sheep based on sex and age. Additionally, phenylalanine, tyrosine, and tryptophan biosynthesis were exclusively associated with age. In univariate linear models, we also discovered that these amino acid and protein pathways were associated with weight by age-corrected effect. Finally, we identified arginine and proline biosynthesis as a pathway linked to metabolites with weight.

Conclusion

Our study identified differential pathways based on the sex, age, and weight features of sheep. Metabolites produced by the rumen may act as an indicator for sheep health and other ruminants. These findings encourage further investigation of the differentially produced metabolites to assess overall sheep health.

The impact of uric acid on musculoskeletal diseases: clinical associations and underlying mechanisms

Serum urate (SU) levels are significantly elevated in conditions such as gout, type 2 diabetes (T2D), obesity, and other metabolic syndromes. Recently, due to the high prevalence of hyperuricemia (HUA), numerous clinical connections between SU and musculoskeletal disorders like sarcopenia, osteoarthritis (OA), rheumatoid arthritis (RA), intervertebral disc degeneration (IDD), and osteoporosis (OP) have been identified. This review discusses the mechanisms linking SU to musculoskeletal disorders, as well as the clinical associations of SU with conditions such as sarcopenia, T2D with sarcopenia, McArdle disease, heart failure, gout, OA, IDD, OP and exercise-induced acute kidney injury (EIAKI), offering valuable insights for improved prevention and treatment strategies. Mechanisms linking SU to musculoskeletal disorders include oxidative stress, MSU (monosodium urate) crystal deposition, inflammation, and other factors. In adults, both age and SU levels should be considered for preventing sarcopenia, while gender and SU may directly impact muscle mass in children and adolescents. HUA and gout may be risk factors for OA progression, although some reports suggest otherwise. A U-shaped relationship between SU and IDD has been reported, particularly in Chinese men, indicating lower or higher SU level may be risk factors for IDD. Maintaining SU levels within a certain range may help prevent OP and fractures. Future research, including epidemiological studies and new pathogenesis findings, will further clarify the relationship between musculoskeletal diseases and SU.

Elevated uric acid levels as a risk factor for new-onset hypertension in newly enrolled Japanese university students (JSH46-0100)

This study aimed to determine the association between serum uric acid (UA) levels and new-onset hypertension (HTN) in newly enrolled students (aged 18 to 20 years) at a university in Gifu, Japan. We analyzed data collected over a 12-year period from April 2010 to March 2022. From this dataset, we selected individuals who were normotensive at admission and underwent a follow-up examination four years later, at the time of their progression to a master's course (n = 2859). Among these participants, 75 (2.6%) developed HTN by the second visit. Their serum UA levels (mg/dL) were significantly higher compared to those who remained HTN-free, both at baseline (6.02 ± 1.06 vs. 5.42 ± 1.17) and at the second visit (6.10 ± 1.20 vs 5.46 ± 1.22). Logistic regression analysis revealed that the odds of developing HTN were higher when considering the mean UA level across both visits (odds ratio: 1.63 per 1 mg/dL increase) compared to either the first or second visit alone. Further analysis of the relationship between elevated mean UA levels (above the cutoff value of 5.7 mg/dL) and the risk of new-onset HTN demonstrated a significant odds ratio of 3.39, which remained significant after adjusting for body mass index and sex. In summary, elevated UA levels are an independent risk factor for future HTN in young adults.

Correlation between Chinese visceral adiposity index and serum uric acid levels in type 2 diabetes mellitus patients

Purpose

The Chinese Visceral Adiposity Index (CVAI), a measure of visceral adiposity dysfunction, is used to assess visceral fat (VFA) malfunction. This research was performed to evaluate the relationship between CVAI and serum uric acid levels in type 2 diabetes mellitus (T2DM) patients.

Methods

A total of 2268 patients with T2DM were enrolled in this study. We collected the general clinical information of patients, measured the basic anthropometric indicators, tested glycolipid metabolism and biochemical indicators, and measured the visceral and subcutaneous fat area with bioelectrical impedance technology. According to the quartiles of the CVAI, the T2DM patients were classified into four groups: group A (CVAI ≤ 94.43), group B (94.43

Results

Among quartiles of CVAI, as CVAI increased, the proportion of patients with HUA gradually increased. The correlation analysis showed that the majority of basal measures, glycolipid metabolism and biochemical indicators were positively correlated with CVAI. By comparison, the level of CVAI in the HUA group was significantly higher than non-HUA group. Meanwhile, through using the ROC curve, our study observed the more predictive value of CVAI than other obesity indicators for T2DM with HUA.

Conclusion

CVAI is a simple but effective indicator, which is significantly correlated with HUA in T2DM and can reflect the incidence of HUA in T2DM patients. As CVAI increased, the risk of HUA in T2DM patients increased. Therefore, we should pay more attention to the application of CVAI in T2DM.

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Key Words

• Chinese visceral adiposity index
• hyperuricemia
• obesity
• type 2 diabetes mellitus
• uric acid

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MESH Headings

• Humans
• Diabetes Mellitus, Type 2/blood
• Male
• Female
• Middle Aged
• Uric Acid/blood
• Intra-Abdominal Fat
• Adiposity
• Aged
• China/epidemiology
• Hyperuricemia/blood
• Adult
• Biomarkers/blood
• Obesity, Abdominal/blood
• East Asian People

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Affiliation(s)

Swailla Amina Araújo Intchasso Adotey
Qian Zhang
Mengxue Chen
Yang Jiao
Yin Zhang
Claudette Butoyi
Dong Wang
Ling Yang
Guoyue Yuan Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, China
Jue Jia Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, China

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Intestinal FXR deficiency induces dysregulation of xanthine oxidase and accounts for sex difference in hyperuricemia

Overproduction of uric acid caused by increased expression and/or enhanced activity of xanthine oxidase (XO) is one of the major etiologies of hyperuricemia, which had a significant sex differences. As an important enzyme involved in production of reactive oxygen species and uric acid, activity of XO is highly correlated with hyperuricemia and its complications. However, the mechanisms underlying XO dysregulation remain unclear, and sex difference in the prevalence of hyperuricemia has been well known. To explore the potential role of intestinal farnesoid X receptor (FXR) on XO regulation and production, and the mechanisms of sex differences in this pathological process. Two hundred and sixty-one dyslipidemia participants and intestine-specific FXR-knockout mice were used to study the relationship between the intestinal FXR and the serum uric acid level. Western blotting, quantitative real-time PCR, and dual-luciferase reporter assay, were applied to clarify the regulatory role of FXR deficiency on XO. Special inhibitors, agonists, siRNA, sex hormones were used to investigate the mechanism of sex difference in FXR deficiency induced hyperuricemia in cell and animal model. Serum fibroblast growth factor 19 (FGF19) levels were lower in hyperuricemia patients in a sex difference manner. Increased local TNFα level driven by intestinal FXR deficiency/inhibition induced overexpression and hyperactivity of intestinal XO, leading to elevated intestinal uric acid synthesis, and subsequently resulting in hyperuricemia. We found that estrogens inhibited XO expression and activity, whereas androgens enhanced XO activity, leading to the sex difference in FXR deficiency induced hyperuricemia. Infliximab treatment eliminated the sex difference in uric acid levels in intestinal FXR-knockout mice. This study demonstrated the role of intestinal FXR in the pathogenesis of hyperuricemia, and partially elucidated the mechanisms underlying the sex differences of hyperuricemia.

Association of circadian syndrome with risk of hyperuricemia among middle-aged and older adults in China: The first nationwide cohort study

OBJECTIVES

No studies have been conducted to explore the association of circadian syndrome (CircS) and hyperuricemia. We addressed the gap by investigating the association of CircS and the risk of hyperuricemia among middle-aged and older adults in China.

STUDY DESIGN

Prospective cohort study.

METHODS

We utilized a nationwide cohort from the China Health and Retirement Longitudinal Study, 7009 adults aged at least 45 years were enrolled at baseline in 2011, and 4415 participants followed up to 2015. CircS was assessed using seven components including five components used to define metabolic syndrome and two components of lack of sleep and depression. Multivariable logistic regression analysis was applied to examine the association of CircS and hyperuricemia. Stratified analyses were used to identify the vulnerable subgroup.

RESULTS

Among the 7009 participants (mean age: 60.6 [SD: 9.8] years), 52.8 % were women. Compared to participants without CircS, those with CircS had a higher risk of hyperuricemia (adjusted odds ratio, aOR 2.246, 95 % CI:1.819-2.773). After 4-year follow-up, 457 (10.4 %) cases developed as hyperuricemia. The longitudinal analyses showed that CircS had a higher risk of incident hyperuricemia (aOR 2.136, 1.740-2.620). The association was stronger in women and those with kidney disease. Sensitivity analysis showed that individuals with ≥ six CircS components had the highest risk of hyperuricemia.

CONCLUSIONS

This nationwide cohort first revealed that CircS was related to an increased risk of hyperuricemia among Chinese adults. Our findings provide epidemiological evidence regarding the importance of CircS management as a preventative strategy for hyperuricemia.

Gout and Hyperuricemia: A Narrative Review of Their Comorbidities and Clinical Implications

Gout is the most common form of inflammatory arthritis, caused by the deposition of monosodium urate crystals in the joints due to elevated serum uric acid levels. Its prevalence and associated healthcare burden have been rising in recent decades, a trend expected to continue. It is crucial to recognize that gout and hyperuricemia are not merely causes of painful joint flares, but systemic metabolic disorders linked to a broad spectrum of comorbidities such as cardiovascular diseases, chronic kidney disease, diabetes, insulin resistance, steatotic liver disease, osteoarthritis, and respiratory and eye diseases. Numerous risk factors for gout and hyperuricemia have been identified, with recent research uncovering further associations with other conditions. To optimize patient outcomes, gout and hyperuricemia must be addressed through a holistic approach that accounts for these risk factors while providing comprehensive management of related comorbidities affecting various organ systems. This review summarizes the current knowledge on the risk factors, comorbidities, and clinical implications of gout and hyperuricemia. Future research should focus on improving patient outcomes by tailoring treatments individually and addressing the underlying metabolic comorbidities of gout with multimodal treatment.

The potential role of uric acid in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder among women of reproductive age and is associated with a variety of multi-system complications. The prevailing treatment strategy for PCOS is to individualize the interventions based on individual symptoms and patient complaints. However, optimal efficacy in treatment necessitates a focus on addressing the underlying pathogenic mechanisms. Uric acid (UA), the end product of purine metabolism, has been suggested to be involved in the development of several diseases, including PCOS. However, the precise mechanisms by which UA may affect PCOS remain incompletely understood. This literature review aims to investigate the correlation between UA and the various clinical presentations of PCOS, such as hyperandrogenism, insulin resistance (IR), ovulation disorders, obesity, and other related manifestations, through the analysis of epidemiological and clinical studies. The purpose of this study is to improve our comprehension of how UA contributes to each aspect of PCOS and their interrelationship, thus identifying the potential role of UA as a facilitator of PCOS. Furthermore, we explore potential pathways linking UA and PCOS, and propose therapeutic interventions based on these findings to optimize the management of this condition.

Systemic inhibition of de novo purine biosynthesis prevents weight gain and improves metabolic health by increasing thermogenesis and decreasing food intake

Objective

Obesity is a major health concern, largely because it contributes to type 2 diabetes mellitus (T2DM), cardiovascular disease, and various malignancies. Increase in circulating amino acids and lipids, in part due to adipose dysfunction, have been shown to drive obesity-mediated diseases. Similarly, elevated purines and uric acid, a degradation product of purine metabolism, are found in the bloodstream and in adipose tissue. These metabolic changes are correlated with metabolic syndrome, but little is known about the physiological effects of targeting purine biosynthesis.

Methods

To determine the effects of purine biosynthesis on organismal health we treated mice with mizoribine, an inhibitor of inosine monophosphate dehydrogenase 1 and 2 (IMPDH1/2), key enzymes in this pathway. Mice were fed either a low-fat (LFD; 13.5% kcal from fat) or a high-fat (HFD; 60% kcal from fat) diet for 30 days during drug or vehicle treatment. We ascertained the effects of mizoribine on weight gain, body composition, food intake and absorption, energy expenditure, and overall metabolic health.

Results

Mizoribine treatment prevented mice on a HFD from gaining weight, but had no effect on mice on a LFD. Body composition analysis demonstrated that mizoribine significantly reduced fat mass but did not affect lean mass. Although mizoribine had no effect on lipid absorption, food intake was reduced. Furthermore, mizoribine treatment induced adaptive thermogenesis in skeletal muscle by upregulating sarcolipin, a regulator of muscle thermogenesis. While mizoribine-treated mice exhibited less adipose tissue than controls, we did not observe lipotoxicity. Rather, mizoribine-treated mice displayed improved glucose tolerance and reduced ectopic lipid accumulation.

Conclusions

Inhibiting purine biosynthesis prevents mice on a HFD from gaining weight, and improves their metabolic health, to a significant degree. We also demonstrated that the purine biosynthesis pathway plays a previously unknown role in skeletal muscle thermogenesis. A deeper mechanistic understanding of how purine biosynthesis promotes thermogenesis and decreases food intake may pave the way to new anti-obesity therapies. Crucially, given that many purine inhibitors have been FDA-approved for use in treating various conditions, our results indicate that they may benefit overweight or obese patients.

Human brain proteome-wide association study provides insights into the genetic components of protein abundance in obesity

BACKGROUNDS

Genome-wide association studies have identified multiple genetic variants associated with obesity. However, most obesity-associated loci were waiting to be translated into new biological insights. Given the critical role of brain in obesity development, we sought to explore whether obesity-associated genetic variants could be mapped to brain protein abundances.

METHODS

We performed proteome-wide association studies (PWAS) and colocalization analyses to identify genes whose cis-regulated brain protein abundances were associated with obesity-related traits, including body fat percentage, trunk fat percentage, body mass index, visceral adipose tissue, waist circumference, and waist-to-hip ratio. We then assessed the druggability of the identified genes and conducted pathway enrichment analysis to explore their functional relevance. Finally, we evaluated the effects of the significant PWAS genes at the brain transcriptional level.

RESULTS

By integrating human brain proteomes from discovery (ROSMAP, N = 376) and validation datasets (BANNER, N = 198) with genome-wide summary statistics of obesity-related phenotypes (N ranged from 325,153 to 806,834), we identified 51 genes whose cis-regulated brain protein abundance was associated with obesity. These 51 genes were enriched in 11 metabolic processes, e.g., small molecule metabolic process and metabolic pathways. Fourteen of the 51 genes had high drug repurposing value. Ten of the 51 genes were also associated with obesity at the transcriptome level, suggesting that genetic variants likely confer risk of obesity by regulating mRNA expression and protein abundance of these genes.

CONCLUSIONS

Our study provides new insights into the genetic component of human brain protein abundance in obesity. The identified proteins represent promising therapeutic targets for future drug development.

Effects of irisin and exercise on adropin and betatrophin in a new metabolic syndrome model

Metabolic syndrome (MetS) is a prevalent public health problem. Uric acid (UA) is increased by MetS. We investigated whether administration of UA and 10% fructose (F) would accelerate MetS formation and we also determined the effects of irisin and exercise. We used seven groups of rats. Group 1 (control); group 2 (sham); group 3 (10% F); group 4 (1% UA); group 5 (2% UA); group 6 (10% F + 1% UA); and Group 7, (10% F + 2% UA). After induction of MetS (groups 3 -7), Group 3 was divided into three subgroups: 3A, no further treatment; 3B, irisin treatment; 3C, irisin treatment + exercise. Group 4, 1% UA, which was divided into three subgroups: 4A, no further treatment; 4B, irisin treatment; 4C, Irisin treatment + exercise. Group 5, 2% UA, which was divided into three subgroups: 5A, no further treatment; 5B, irisin treatment; 5C, irisin treatment + exercise. Group 6, 10% F + 1% UA, which was divided into three subgroups: 6A, no further treatment; 6B, irisin treatment; 6C, irisin treatment + exercise. Group 7, 10% F + 2% UA, which was divided into three subgroups: 7A, no further treatment; 7B, irisin treatment; 7C, irisin treatment + exercise., İrisin was administered 10 ng/kg irisin intraperitoneally on Monday, Wednesday, Friday, Sunday each week for 1 month. The exercise animals (in addition to irisin treatment) also were run on a treadmill for 45 min on Monday, Wednesday, Friday, Sunday each week for 1 month. The rats were sacrificed and samples of liver, heart, kidney, pancreas, skeletal muscles and blood were obtained. The amounts of adropin (ADR) and betatrophin in the tissue supernatant and blood were measured using an ELISA method. Immunohistochemistry was used to detect ADR and betatrophin expression in situ in tissue samples. The duration of these experiments varied from 3 and 10 weeks. The order of development of MetS was: group 7, 3 weeks; group 6, 4 weeks; group 5, 6 weeks; group 4, 7 weeks; group 3, 10 weeks. Kidney, liver, heart, pancreas and skeletal muscle tissues are sources of adropin and betatrophin. In these tissues and in the circulation, adropin was decreased significantly, while betatrophin was increased significantly due to MetS; irisin + exercise reversed this situation. We found that the best method for creating a MetS model was F + UA2 supplementation. Our method is rapid and simple. Irisin + exercise was best for preventing MetS.

Exploring the Relationship Between Different Obesity Metabolism Indices and Hyperuricemia in Patients with Hypertension and Coronary Heart Disease

Background

Previous studies have established a strong association between obesity, high metabolism, and the development of hyperuricemia. However, the relationship between obesity metabolism indices and hyperuricemia in high-risk patients with hypertension and coronary heart disease (CHD) remains unclear. The purpose of this study was to investigate this relationship in patients with both hypertension and CHD, and to identify the obesity metabolism index with the best diagnostic value.

Methods

A two-center study encompassed 6344 participants with hypertension and CHD. Multiple logistic regression was utilized to examine the correlation between six obesity metabolism indices and hyperuricemia, with restricted cubic spline (RCS) analysis to identify non-linear relationships. Diagnostic value was assessed via receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

Results

Multivariable logistic regression revealed a significant correlation between increased obesity metabolism indices and hyperuricemia. Furthermore, RCS analysis revealed a nonlinear dose-response relationship (P for nonlinear < 0.001). Moreover, ROC and DCA results showed that METS-VF index, which combined visceral obesity and metabolic parameters, became the most reliable diagnostic tool.

Conclusion

The study underscores a strong association between elevated obesity metabolism indices and hyperuricemia in patients with hypertension and CHD. The METS-VF index, amalgamating visceral obesity and metabolic parameters, emerged as the most reliable diagnostic tool.

Phosphorus modifies the association between body mass index and uric acid: Results from NHANES 2007-2018

INTRODUCTION

Studies in recent years have shown that high uric acid causes harm to the human body, which has become a serious public health problem. Elevated serum uric acid has been shown to be associated with obesity, but the relationship between BMI and uric acid (UA) remains controversial. Although the association between BMI and UA has been well studied, the effect of phosphorus levels in vivo on this association remains unclear. This study aimed to determine the relationship between BMI and serum uric acid and the effect of phosphorus on the relationship between the two.

RESEARCH DESIGN AND METHODS

The present study analyzed data from the National Health and Nutrition Examination Survey (NHANES) continuous 2007-2018 cycle. We included 10786 participants aged 20 years and over. Multivariable linear regression was performed to assess the association between BMI and serum uric acid. phosphorus was stratified into low phosphorus (<3.3 mg/dl), middle phosphorus (3.3-3.9 mg/dl) and high phosphorus (>3.9 mg/dl). Correction of the effect of phosphorus was assessed by testing the interaction between BMI and UA in multivariate linear regression.

RESULTS

In this cross-sectional study, we found that BMI was positively associated with UA in the female population but not significantly in the male population or in the total population. In multiple regression analysis, UA was 0.51 higher in the highest female BMI group than in the lowest group (p = 0.0001). The relationship between BMI and UA differed significantly by gender under the influence of phosphorus, with men and women in Model II having a greater elevation of UA in men than in women within most groups. (BMI >30, phosphorus >3.9 mg/dl, β:0.83 95% CI: 0.43, 1.23 vs β: 0.79 95% CI: 0.30, 1.29). In addition, phosphorus significantly altered the positive association between BMI and UA in most models.

CONCLUSION

Our results indicate significant associations between BMI and uric acid in women, with higher BMI values likely to be associated with a higher risk of hyperuricemia, suggesting that uric acid levels in obese people should be closely monitored in clinical practice. Phosphorus and BMI have an interactive effect in elevating UA and should be noted as indicators of phosphorus in clinical practice.

Disruption of nucleotide biosynthesis reprograms mitochondrial metabolism to inhibit adipogenesis

A key organismal response to overnutrition involves the development of new adipocytes through the process of adipogenesis. Preadipocytes sense changes in the systemic nutrient status and metabolites can directly modulate adipogenesis. We previously identified a role of de novo nucleotide biosynthesis in adipogenesis induction, whereby inhibition of nucleotide biosynthesis suppresses the expression of the transcriptional regulators PPARγ and C/EBPα. Here, we set out to identify the global transcriptomic changes associated with the inhibition of nucleotide biosynthesis. Through RNA sequencing (RNAseq), we discovered that mitochondrial signatures were the most altered in response to inhibition of nucleotide biosynthesis. Blocking nucleotide biosynthesis induced rounded mitochondrial morphology, and altered mitochondrial function, and metabolism, reducing levels of tricarboxylic acid cycle intermediates, and increasing fatty acid oxidation (FAO). The loss of mitochondrial function induced by suppression of nucleotide biosynthesis was rescued by exogenous expression of PPARγ. Moreover, inhibition of FAO restored PPARγ expression, mitochondrial protein expression, and adipogenesis in the presence of nucleotide biosynthesis inhibition, suggesting a regulatory role of nutrient oxidation in differentiation. Collectively, our studies shed light on the link between substrate oxidation and transcription in cell fate determination.

Spectrum of orbital fat necrosis in rhino-orbital-cerebral mucormycosis in post-COVID-19 patients

PURPOSE

Rhino-orbital-cerebral mucormycosis (ROCM) is the most common presentation of mucormycosis. Sinonasal-orbital debridement with exenteration is a life-saving procedure in ROCM patients in view of severe involvement of sinuses and the eyeball. Following the second wave of coronavirus disease 2019 (COVID-19), there was a massive surge in mucormycosis cases in India in post-COVID-19 patients. Of over 300 cases of mucormycosis admitted in our hospital, many underwent exenteration and these specimens were evaluated histopathologically, where fat necrosis was found to be a prominent finding. The spectrum of fat necrosis in ROCM in orbital fat has not been described in literature. Hence, we sought to evaluate the significance and spectrum of orbital fat necrosis in ROCM.

METHODS

This 3-month retrospective study included 15 cases of ROCM which underwent exenteration. Clinical data, radiologic details, and histopathologic findings were tabulated. Sections were also subjected to Periodic acid Schiff (PAS) and Gomori's methenamine silver (GMS) stains for confirming the fungus.

RESULTS

All 15 cases showed fat stranding on computed tomography (CT) scan. On histopathologic examination, various tissue reaction patterns observed included acute/chronic inflammatory infiltrate, suppurative granulomas with giant cells, coagulative and fat necrosis, broad aseptate fungal hyphae with or without angioinvasion, and neural invasion. Fungal hyphae were confirmed with PAS and GMS stains. The spectrum of fat necrosis observed in all the cases included 1) acute necrotizing fat necrosis, 2) ghost adipocytes with or without saponification, and 3) crystalline/gouty fat necrosis.

CONCLUSION

Fat necrosis is a significant finding in ROCM, both on CT scan and histopathology. All three patterns of fat necrosis may be observed simultaneously in a case of ROCM.

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

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

Association of uric acid with body adiposity and biochemical parameters in kidney transplant patients

BACKGROUND

Obesity and various biochemical parameters, including triglycerides, cholesterol, glucose, C-reactive protein, and estimated glomerular filtration rate, have been linked to elevated uric acid (UA) levels in populations with normal kidney function due to decreased UA excretion and/or increased UA synthesis. However, it remains unclear whether all these factors exhibit similar associations with UA levels in clinical populations characterized by compromised renal function, such as kidney transplant patients (KTPs).

OBJECTIVE

To evaluate whether serum UA levels are associated with body adiposity and biochemical parameters in KTPs.

METHODS

A cross-sectional study involving 113 KTPs was conducted. Body fat was estimated using bioelectrical impedance, and waist circumference was measured using an inelastic tape. Serum levels of UA, creatinine, glucose, triglycerides, total cholesterol, and its fractions were measured using the colorimetric method. C-reactive protein levels were assessed using the immunoturbidimetric method, and urea levels were determined via enzymatic kinetics. Glomerular filtration rate was estimated using the chronic kidney disease epidemiology collaboration equation. Linear regression analyses were employed to assess the association between serum UA levels and body adiposity as well as biochemical parameters, while adjusting for confounders.

RESULTS

Serum UA levels exhibited a positive association with creatinine (β = 0.402; p = 0.013) and urea (β = 0.024; p = 0.001), while demonstrating an inverse association with estimated glomerular filtration rate (β = -0.030; p < 0.001). However, serum UA levels were not significantly associated with fat mass (both in kilograms and as a percentage), waist circumference, triglycerides, C-reactive protein, glucose, HDL cholesterol, LDL cholesterol, VLDL cholesterol, or total cholesterol.

CONCLUSION

Serum UA levels are only associated with biochemical parameters linked to renal function in KTPs. Consequently, in individuals with suboptimal renal function, such as KTPs, UA does not exhibit associations with other biochemical parameters and body adiposity, as commonly observed in non-renal disease populations.

EUS-FNA diagnosis of pancreatic tophaceous gout: Two rare cases

We report two patients with pancreatic tophaceous gout diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of presumed cystic mass lesions. The first case involved a patient who had a recent episode of acute pancreatitis 6 months prior, with subsequent imaging concerning for a pseudocyst or mass lesion. The second case involved a patient with epigastric pain associated with a pancreatic head cystic mass and an erroneous original diagnosis of a mucinous pancreatic neoplasm on EUS-FNA. Diff-Quik stained direct smears on fresh material obtained from EUS-FNA of the lesions showed chalky debris with needle shaped negatively birefringent crystals consistent with gout. For the first case, the chalky material was not present on the H&E stained paraffin embedded formalin fixed cellblock slides. The importance of inclusion of cytologic specimen preparations to examine monosodium urate crystals is emphasized.

Obesity-Associated Hyperuricemia in Female Mice: A Reevaluation

Many preclinical reports have coalesced to identify a strong association between obesity and increased levels of uric acid (UA) in tissues and, importantly in the circulation (hyperuricemia). Unfortunately, nearly all these studies were conducted with male mice or, in one case, female mice without a side-by-side male cohort. Therefore, the relationship between obesity and hyperuricemia in female mice remains undefined. This lack of clarity in the field has considerable impact as the downstream effects of obesity and allied hyperuricemia are extensive, resulting in many comorbidities including cardiovascular dysfunction, chronic kidney disease and nonalcoholic fatty liver disease (NAFLD). Herein we begin to address this issue by revealing phenotypic and metabolic responses to diet-induced obesity (DIO) in a side-by-side male vs. female C57BL/6J study. Beginning at 6 weeks of age, mice were exposed to either an obesogenic diet (60% calories from fat) or control diet (10% calories from fat) for 19 weeks. Similar to numerous reported observations with the 60% diet, male mice experienced significant weight gain over time, elevated fasting blood glucose, impaired glucose tolerance and significantly elevated circulating uric acid levels (2.54 ± 0.33 mg/dL) compared to age-matched lean male controls (1.53 ± 0.19 mg/dL). As expected, the female mice experienced a slower rate of weight gain compared to the males; however, they also developed elevated fasting blood glucose and impaired glucose tolerance compared to age-matched lean controls. Countervailing our previous report whereby the control diet for the female-only study was vivarium standard chow (18% calories from fat), the obese female mice did demonstrate significantly elevated circulating UA levels (2.55 ± 0.15 mg/dL) compared to the proper control (1.68 ± 0.12 mg/dL). This affirms that the choice of control diet is crucial for reaching durable conclusions. In toto, these results, for the first time, reveal elevated circulating UA to be a similar long-term response to obesogenic feeding for both males and females and mirrors clinical observations demonstrating hyperuricemia in obesity for both sexes.

Relationship between serum vitamin C and serum uric acid in people with different BMIs: results from the NHANES 2017-2018 and Mendelian randomization study

Objective

To examine the association of overweight/obesity and serum vitamin C (serum VC) with serum uric acid (SUA) and to assess causality using Mendelian randomization (MR).

Methods

4,772 participants from the National Health and Nutrition Examination Survey (NHANES), 2017-2018 were included in this study. Multivariate linear regression, variance inflation factor and quantile regression were used to analyze the relationships between overweight/obesity and serum VC and SUA levels. Secondly, Mendelian randomization (MR) was utilized to mitigate bias and prevent reverse causality in the observational study. Genetic variants associated with obesity (N = 13,848), vitamin C levels (N = 64,979) and serum uric acid levels (N = 343,836) were sourced from the most extensive genome-wide association studies (GWAS). The primary analytical method employed was inverse variance weighted (IVW).

Results

Based on the observational study, BMI was positively associated with SUA (β = 0.06, 95% CI: 0.05 to 0.07, p < 0.001) and serum VC was negatively associated with SUA (β = -0.14, 95% CI: -0.23 to -0.04, p = 0.005). In individuals with overweight/obesity (BMI > =25), the negative effects of serum VC on SUA enhanced with increasing serum VC. High serum VC level (Q4 level, above 1.19 mg/dL) reduced SUA (β = -0.30, 95% CI: -0.47 to -0.14, p < 0.001) in individuals with overweight/obesity compared to low serum VC level (Q1 level, below 0.54 mg/dL). IVW-MR analysis revealed a significant association between SUA levels and genetically elevated levels of VC (β = -0.03, 95% CI: -0.06 to -0.00, p = 0.029) and obesity (β = 0.06, 95% CI: 0.04 to 0.07, p < 0.001).

Conclusion

Cross-sectional observational analysis revealed that BMI exhibited a positive correlation with SUA levels and that serum VC was negatively correlated with SUA levels; moreover, moderate serum VC can reduce SUA, especially in individuals with overweight/obesity. There was evidence indicating a causal effect of VC and obesity on SUA. It highlights the importance of VC in the management of SUA levels, particularly in overweight/obese individuals. The findings might be helpful for the management of high SUA levels.

Effects of Febuxostat Therapy on Circulating Adipokine Profiles in Patients with Overweight or Obesity and Asymptomatic Hyperuricemia: A Randomized Controlled Study

INTRODUCTION

Elevated levels of serum uric acid (SUA) are strongly associated with several components of the metabolic syndrome, particularly obesity. Previous studies have reported the correlation between SUA levels, xanthine oxidoreductase (XOR) activity, and the imbalanced adipokine levels that are characteristic of obesity. In this study, we explored the effect of febuxostat on circulating adipokine profiles in patients with overweight or obesity and asymptomatic hyperuricemia.

METHODS

This study was a single-center, randomized, and controlled clinical trial that enrolled 130 participants with asymptomatic hyperuricemia and obesity. One hundred seventeen participants were included in the final analysis, with 60 participants in the febuxostat group and 57 in the control group. We compared the circulating adipokine levels at 3 and 6 months, including high molecular weight (HMW) adiponectin, chemerin, omentin, monocyte chemotactic protein-1, asprosin, fibroblast growth factor 21, neuregulin-4, leptin, resistin, vaspin, visfatin, adipsin, and assessed the correlation between changes in adipokine levels (Δadipokines) and changes in XOR activity (ΔXOR) after febuxostat treatment.

RESULTS

The results showed that an increase in HMW adiponectin and omentin levels and a decrease in chemerin and asprosin levels at 3 or 6 months compared to the control group. Additionally, a positive correlation was observed between ΔXOR activity and Δasprosin. Furthermore, after adjusting for triglyceride (ΔTG) and serum uric acid (ΔSUA) in multiple linear regression analyses, we found that ΔXOR activity was independently correlated with Δasprosin.

CONCLUSION

This study may provide important evidence that febuxostat could alleviate the imbalance in circulating adipokine levels in patients with overweight or obesity and asymptomatic hyperuricemia. Furthermore, we observed a positive correlation between changes in asprosin levels and changes in XOR activity after febuxostat treatment.

Orlistat and metformin combination ameliorates obesity-induced renal injury via suppressing renal oxidative stress in male rats

BACKGROUND

Orlistat (ORS) and metformin (MEF) are robustly used as well-established clinical drugs for the treatment for both obesity and the consequences of diabetes mellitus. Additionally, no study has been conducted to explore the consequence of the combination of both ORS and MEF on the kidneys of rats with obesity-induced renal injury (OBS).

OBJECTIVES

Therefore, the objective of the current research was designed to explore the possible ameliorative effects of either ORS and/or MEF or their combination against obesity (OBS) induced experimental renal oxidative stress.

METHODS

Renal oxidative stress was investigated at redox histopathological and immunohistological points in the kidney tissues.

RESULTS

The levels of urea, uric acid, and creatinine increased with the obesity effect; in addition, the myeloperoxidase (MPO) and xanthine oxidase (XO) activators were elevated significantly with the induction of OBS. The levels of non-enzymatic antioxidants (glutathione and thiol) declined sharply in OBS rats as compared to the normal group.

CONCLUSION

The data displayed that the combination of both ORS and MEF declined the obesity effects significantly by reducing the level of peroxidation (MDA), and enhancement intracellular antioxidant enzymes. These biochemical findings were supported by histopathology, immunohistochemistry, and Masson-Trichrome evaluation, which showed minor morphological changes in the kidneys of rats.

Assessing levels of uric acid and other cardiovascular markers in prehypertensive and hypertensive adults

INTRODUCTION

Although some studies have reported the association between uric acid (UA) and hypertension, evidence on prehypertension is still lacking. Therefore, the objective of this study was to determine the levels of UA and other cardiovascular markers among prehypertensive and hypertensive patients and assess their risk for developing arterial hypertension.

METHODS

157 individuals were recruited: 67 normotensive, 23 pre-hypertensive and 67 hypertensive. Blood samples were collected to measure biochemical parameters and anthropometric measurements and blood pressure were evaluated. We calculated the product of lipid accumulation and the visceral adiposity index to assess cardiovascular risk.

RESULTS

Our data showed an increase in UA levels in normotensives (4.9±1.3mg/dL), prehypertensives (5.2±1.3mg/dL) and hypertensives (5.9±1.6mg/dL) (p=0.004). We found a higher frequency of hyperuricemia in the hypertensive group (34.3%) than in the normotensive group (13.4%, p<0.05). Hypertensive volunteers had lower levels of HDL-C (p=0.004 and p=0.003) and higher body mass indexes (p<0.001 and p=0.007), glucose (p<0.001 and p=0.033), triglycerides (p=0.001 and p=0.005), visceral adiposity index (p<0.001 and p=0.002) and lipid accumulation product (p<0.001 and p=0.007) than normotensive and prehypertensive participants. We also observed that individuals with UA≥6.2mg/dL had an increased risk of hypertension of 4.77 (p=0.003) compared to individuals with levels≤4.3mg/dL.

CONCLUSION

Our results showed that UA is associated with increased blood pressure and unfavorable changes in anthropometric and biochemical parameters, which represent risk factors for hypertension and cardiovascular diseases.

A Nationwide Nepalese Study to Establish Reference Intervals for Major Biochemical Analytes with Elucidation of Nepalese Features of Reference Values

Despite immense importance of reference intervals (RIs) for clinical diagnosis, there have been no reliable RIs available for Nepalese. Hence, this nationwide study was organized to establish RIs for 30 common biochemical parameters. This study was conducted following the harmonized protocol provided by IFCC Committee on Reference Interval and Decision Limits (C-RIDL) with recruitment of 617 apparently healthy volunteers (18 - 65 years) by near-equal gender balance from 5 major cities. Fasting blood were collected, serum was separated and measured collectively using Beckman-Coulter/Olympus AU480 chemistry analyzer. The sources of variations of reference values (RVs) were evaluated by multiple regression analysis and nested ANOVA. Latent abnormal values exclusion (LAVE) method was applied to reduce influence of latent diseases. RIs were standardized based on a value-assigned serum panel provided by C-RIDL. By ANOVA, no between-city differences were observed, while sex-related changes were typically noted for urate, creatinine, iron, γ-glutamyl transferase (GGT), immunoglobulin M, and transferrin, but not for high-density lipoprotein cholesterol. Age-related changes were observed for total cholesterol (TC), triglyceride, low-density lipoprotein cholesterol, and C-reactive protein (CRP). RIs were successfully derived all parametrically. The LAVE procedure was effective in lowering upper limits for aspartate aminotransferase, alanine aminotransferase (ALT), and CRP. Compared to other collaborating countries, Nepalese RIs were low for urea, cholesterols, ALT, and high for triglyceride, GGT, CRP, immunoglobulin G, and complements. The RIs for major chemistry analytes were derived and standardized for nationwide use in Nepal. This study distinctly elucidated sources of variation and international features of Nepalese RIs.

Supplementary Information

The online version supplementary material available at 10.1007/s12291-023-01123-6.

Plasma Uric Acid, Lactate, and Osmolality in Colorectal Cancer

A complex evaluation of colorectal cancer (CRC) in relation to screening, diagnosis, stage determination, prognosis, and treatment requires valuable biomarkers. The aim of this study was to measure selected biomarkers—uric acid (UA), lactate, Na+, Cl−, and osmolality—in CRC patients and to assess their diagnostic value to distinguish between CRC and healthy controls. Plasma lactate (2.21 ± 0.11 vs. 2.88 ± 0.19, p < 0.01), Na+ (130.79 ± 0.42 vs. 133.23 ± 0.25, p < 0.001), Cl− (102.59 ± 0.45 vs. 103.94 ± 0.23, p < 0.01), and osmolality (266.44 ± 0.86 vs. 271.72 ± 0.62, p < 0.001) were found to be significantly lower in CRC patients as compared to the healthy controls group. Among them, with satisfactory diagnostic potential, were plasma Na+ concentrations and osmolality (AUCNa+ = 0.752, p < 0.0001; AUCosmolality = 0.757, p < 0.05), respectively. UA concentrations were detected at higher concentrations in CRC patients (333.67 ± 13.05 vs. 295.88 ± 13.78, p < 0.05). The results of this study contribute to the elucidation of molecular mechanisms of CRC pathogenesis and the role of studied metabolic parameters in this process. Plasma uric acid, lactate, and osmolality parameters can be used for screening and monitoring colorectal cancer. Further studies are required to elucidate the molecular mechanisms of their action in cancer development. The action of circulating plasma lactate may be different from those locally produced in the tumor microenvironment.

A combined association of obesity, alanine aminotransferase and creatinine with hyperuricemia in youth aged 13-20 years

Background

Despite extensive research on hyperuricemia (HUA) in adults, there remains a dearth of studies examining this condition in youth. Consequently, our objective was to investigate the prevalence of HUA among youth in the United States, as well as identify the corresponding risk factors.

Methods

This study employed a nationally representative subsample of 1,051 youth aged 13-20 from the US National Health and Nutrition Examination Survey (NHANES) conducted between January 2017 and March 2020. Univariate and multivariate techniques were utilized to examine the association between HUA and obesity, dietary nutrients, liver and kidney function, glucose and lipid metabolism, inflammation, and other indicators in the adolescent population.

Results

The study encompassed a cohort of 1,051 youth aged 13-20 years, comprising 538 boys and 513 girls. The overall prevalence of HUA was found to be 7% (74 out of 1,051). Univariate analysis revealed that the HUA group exhibited greater age, body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR). Additionally, the prevalence of obesity was significantly higher in the HUA group compared to the non- HUA group (all p < 0.05). Regarding biochemical indicators, the levels of urea nitrogen, creatinine (Cr), alanine aminotransferase (ALT), glutamic oxalic aminotransferase (AST), gamma-glutamyl transferase (GGT), total cholesterol (TC), triglyceride (TG), and HS C reactive protein (Hs CRP) were found to be significantly higher in the HUA group compared to the non-HUA group (all p < 0.05). Further analysis using binary logistics regression showed that BMI (p = 0.024, OR1.158, 95%CI1.019-1.316), ALT (p = 0.020, OR1.032, 95%CI1.005-1.059), and Cr (p = 0.016, OR1.028, 95%CI1.005-1.051) were identified as risk factors for HUA, after controlling for age, gender, BMI, WC, HC, WHR, ALT, AST, GGT, TG, TC, Cr, Hs CRP, and other indicators. Interestingly, neither univariate nor multivariate analysis found any association between dietary nutrients and the risk of HUA (all p > 0.05).

Conclusion

High BMI remains a major risk factor for HUA in US youth aged 13-20 years, and ALT and Cr levels should be closely monitored along with serum uric acid.

Development and validation of a predictive model for severe white matter hyperintensity with obesity

Purpose

The purpose of the present study was to identify predictors of severe white matter hyperintensity (WMH) with obesity (SWO), and to build a prediction model for screening obese people with severe WMH without Nuclear Magnetic Resonance Imaging (MRI) examination.

Patients subjects and methods

From September 2020 to October 2021, 650 patients with WMH were recruited consecutively. The subjects were divided into two groups, SWO group and non-SWO group. Univariate and Logistic regression analysis were was applied to explore the potential predictors of SWO. The Youden index method was adopted to determine the best cut-off value in the establishment of the prediction model of SWO. Each parameter had two options, low and high. The score table of the prediction model and nomogram based on the logistic regression were constructed. Of the 650 subjects, 487 subjects (75%) were randomly assigned to the training group and 163 subjects (25%) to the validation group. By resampling the area under the curve (AUC) of the subject's operating characteristics and calibration curves 1,000 times, nomogram performance was verified. A decision curve analysis (DCA) was used to evaluate the nomogram's clinical usefulness. By resampling the area under the curve (AUC) of the subject's operating characteristics and calibration curves 1,000 times, nomogram performance was verified. A decision curve analysis (DCA) was used to evaluate the nomogram's clinical usefulness.

Results

Logistic regression demonstrated that hypertension, uric acid (UA), complement 3 (C3) and Interleukin 8 (IL-8) were independent risk factors for SWO. Hypertension, UA, C3, IL-8, folic acid (FA), fasting C-peptide (FCP) and eosinophil could be used to predict the occurrence of SWO in the prediction models, with a good diagnostic performance, Areas Under Curves (AUC) of Total score was 0.823 (95% CI: 0.760-0.885, p < 0.001), sensitivity of 60.0%, specificity of 91.4%. In the development group, the nomogram's AUC (C statistic) was 0.829 (95% CI: 0.760-0.899), while in the validation group, it was 0.835 (95% CI: 0.696, 0.975). In both the development and validation groups, the calibration curves following 1,000 bootstraps showed a satisfactory fit between the observed and predicted probabilities. DCA showed that the nomogram had great clinical utility.

Conclusion

Hypertension, UA, C3, IL-8, FA, FCP and eosinophil models had the potential to predict the incidence of SWO. When the total score of the model exceeded 9 points, the risk of SWO would increase significantly, and the nomogram enabled visualization of the patient's WMH risk. The application prospect of our models mainly lied in the convenient screening of SWO without MRI examination in order to detect SWO and control the WMH hazards early.

Genetic Determinants of Thiazide-Induced Hyperuricemia, Hyperglycemia, and Urinary Electrolyte Disturbances - A Genome-Wide Evaluation of the UK Biobank

Thiazide diuretics, widely used in hypertension, cause a variety of adverse reactions, including hyperglycemia, hyperuricemia, and electrolyte abnormalities. In this study, we aimed to identify genetic variants that interact with thiazide-use to increase the risk of these adverse reactions. Using UK Biobank data, we first performed genomewide variance quantitative trait locus (vQTL) analysis of ~ 6.2 million SNPs on 95,493 unrelated hypertensive White British participants (24,313 on self-reported bendroflumethiazide treatment at recruitment) for 2 blood (glucose and urate) and 2 urine (potassium and sodium) biomarkers. Second, we conducted direct gene-environment interaction (GEI) tests on the significant (P < 2.5 × 10-9) vQTLs, included a second UK Biobank cohort comprising 13,647 unrelated hypertensive White British participants (3,478 on thiazides other than bendroflumethiazide) and set significance at P = 0.05 divided by the number of vQTL SNPs tested for GEIs. The vQTL analysis identified eight statistically significant SNPs for blood glucose (5 SNPs) and serum urate (3 SNPs), with none being identified for the urinary biomarkers. Two of the SNPs (1 glucose SNP: CDKAL1 intron rs35612982, GEI P = 6.24 × 10-3; and 1 serum urate SNP: SLC2A9 intron rs938564, GEI P = 4.51 × 10-4) demonstrated significant GEI effects in the first, but not the second, cohort. Both genes are biologically plausible candidates, with the SLC2A9-mediated interaction having been previously reported. In conclusion, we used a two-stage approach to detect two biologically plausible genetic loci that can interact with thiazides to increase the risk of thiazide-associated biochemical abnormalities. Understanding how environmental exposures (including medications such as thiazides) and genetics interact, is an important step toward precision medicine and improved patient outcomes.

Clustering of gout-related comorbidities and their relationship with gout flares: a data-driven cluster analysis of eight comorbidities

OBJECTIVES

To study the aggregation of multiple comorbidities in people with gout and explore differences in prognosis of gout flares among different subgroups.

METHODS

Hierarchical clustering was performed to identify homogeneous subgroups among 2639 people with gout using eight comorbidities. A one-year follow-up of acute gout flares in 463 of these people was conducted; the incidence and the timing of gout flares in each cluster were assessed to explore prognosis of gout flares. Binary logistic regression was applied to assess factors associated with gout flares.

RESULTS

In baseline study, we identified five subgroups (C1-C5). C1 (n = 671, 25%) was characterized by isolated gout with few comorbidities. C2 (n = 258, 10%) were all obese. Almost all people in C3 (n = 335, 13%) had diabetes (99.7%). All people in C4 (n = 938, 36%) had dyslipidemia. C5 (n = 437, 17%) had the highest proportion of cardiovascular disease (CVD, 53%), chronic kidney disease (CKD, 56%), and cancer (7%). In follow-up study, C5 had the highest incidence (71.9%) and earliest onset (median 3 months) of gout flares. C2 had the lowest incidence (52.1%) and the latest onset (median 10 months) of gout flares. The highest relative risk for gout recurrent was seen for C5 (OR = 2.09). Other factors associated with the risk of gout flares were age at diagnosis of gout, duration of gout, presence of tophi, and smoking ≥ 20 cigarettes/day.

CONCLUSIONS

We clustered people with gout into five groups with varying comorbidities. People with CVD, CKD, and cancer had the highest risk of gout flares and should receive comprehensive care.

Fractional Excretion of Urate is Positively Associated with Type 2 Diabetes in HUA Patients: A Cross-Sectional Study

Purpose

People with hyperuricemia (HUA) are often related to metabolic disorders such as diabetes, metabolic syndrome (MetS), and obesity. However, the correlation between excretion of uric acid and these diseases is unclear. Our study aimed to explore the relationship between uric acid excretion and type 2 diabetes (T2D).

Methods

A total of 228 HUA patients from Tianjin Medical University General Hospital from 2022 to 2023 were included in this study. We collected demographic, biochemical, and anthropometric data on each subject. Urine uric acid excretion (UUAE) was calculated enzymatically from a single urine collection that lasted 24 hours. And fractional excretion of uric acid (FEUA) was calculated from serum uric acid and creatinine and uric acid and creatinine. Binary logistic regression modeling assessed the association between uric acid excretion and T2D.

Results

Of the 228 subjects, 13.4% had T2D and 48.7% had obesity. The obesity group had a lower FEUA (p<0.05) and a higher UUAE compared to the control group (p<0.05). And FEUA had a stronger correlation with the risk of T2D (p<0.001). Also, there was a negative association between BMI and FEUA and a positive link between BMI and UUAE in the outpatients.

Conclusion

Increased FEUA levels were significantly associated with T2D in HUA patients. Therefore, routine calculating of FEUA is essential for proper diagnosis and appropriate treatment T2D of in HUA patients.

Nonlinear relationship between body mass index and serum uric acid: An observational and Mendelian randomization study among Chinese adults

BACKGROUND AND AIMS

Conflicting evidence exists on the relationship between body mass index (BMI) and serum uric acid (SUA), and importantly, the causal role of BMI in SUA remains unclear. We aimed to evaluate the BMI-SUA relationship and its causality among Chinese adults using observational and Mendelian randomization (MR) analyses.

METHODS AND RESULTS

Study included 6641 adults from East China. A genetic risk score based on 14 BMI-associated East Asian variants was formulated. One-sample MR and non-linear MR analyses assessed the causal link between BMI_GRS and SUA levels. Mean BMI levels were 24.8 (SD 3.4) and 24.3 (SD 3.6) kg/m2 in men and women, respectively. Spline models revealed gender-specific BMI-SUA associations: a reverse J-shape for men and a J-shape for women (P-values for nonlinearity <0.05). In men, BMI showed a positive correlation with SUA levels when BMI was below 29.6 kg/m2 (beta coefficient 19.1 [95 % CI 15.1, 23.0] μmol/L per 1-SD increase in BMI), while in women, BMI exhibited a negative correlation with SUA levels when the BMI was less than 21.7 kg/m2 (beta coefficient -12.9 [95 % CI -21.6, -4.1] μmol/L) and a positive correlation when BMI exceeded 21.7 kg/m2 (beta coefficient 13.3 [95 % CI 10.9, 15.8] μmol/L). Furthermore, MR analysis suggested non-linear BMI-SUA link in women but not men.

CONCLUSION

Our study indicates a non-linear correlation between BMI and SUA in both genders. It is noteworthy that in women, this correlation may have a causal nature. Nevertheless, further longitudinal investigations are required to authenticate our findings.

Gender-specific association between blood cell parameters and hyperuricemia in high-altitude areas

Background

Hyperuricemia is a common metabolic disorder linked to various health conditions. Its prevalence varies among populations and genders, and high-altitude environments may contribute to its development. Understanding the connection between blood cell parameters and hyperuricemia in high-altitude areas can shed light on the underlying mechanisms. This study aimed to investigate the relationship between blood cell parameters and hyperuricemia in high-altitude areas, with a particular focus on gender differences.

Methods

We consecutively enrolled all eligible Tibetan participants aged 18-60 who were undergoing routine medical examinations at the People's Hospital of Chaya County between January and December 2022. During this period, demographic and laboratory data were collected to investigate the risk factors associated with hyperuricemia.

Results

Among the participants, 46.09% were diagnosed with hyperuricemia. In the male cohort, significant correlations were found between serum uric acid (SUA) levels and red blood cell (RBC) count, creatinine (Cr). Urea, alanine transaminase (ALT), and albumin (ALB). Notably, RBC exhibited the strongest association. Conversely, in the female cohort, elevated SUA levels were associated with factors such as white blood cell (WBC) count. Urea, ALT, and ALB, with WBC demonstrating the most significant association. Further analysis within the female group revealed a compelling relationship between SUA levels and specific white blood cell subtypes, particularly neutrophils (Neu).

Conclusion

This study revealed gender-specific associations between SUA levels and blood cell parameters in high-altitude areas. In males, RBC count may play a role in hyperuricemia, while in females, WBC count appears to be a significant factor. These findings contribute to our understanding of metabolic dynamics in high-altitude regions but require further research for comprehensive mechanistic insights.

Efficacy and safety of orlistat in male patients with overweight/obesity and hyperuricemia: results of a randomized, double-blind, placebo-controlled trial

BACKGROUND

Obesity is associated with elevated serum uric acid (SUA) levels and frequent gout flares. Losing weight can reduce the SUA level and gout flares. The effect of orlistat on SUA levels and gout flares in patients with overweight/obesity and hyperuricemia (HUA) has not been extensively studied. This study investigated the effects of orlistat on SUA levels and gout flares compared to placebo in overweight and obese patients with HUA.

METHODS

A total of 72 Chinese patients with overweight/obesity and HUA were randomly divided into a placebo group (35, 48.6%) and an orlistat group (37, 51.4%); the trial lasted 12 weeks. The primary endpoints were the relative changes in body weight, the SUA level, and gout flares in the per-protocol population.

RESULTS

Orlistat reduced the proportion of patients with gout flares (log-rank P = 0.023, hazard ratio = 0.31, 95% confidence interval 0.11-0.85). There was no significant difference in SUA level between the two groups. The average weight loss of the orlistat group was 2.85 kg, and the average weight loss of the placebo group was 0.76 kg. The weight loss in the orlistat group was significantly greater than that in the control group (P < 0.05).

CONCLUSIONS

This study is the first to demonstrate that orlistat has no significant effect on SUA levels in patients with overweight/obesity and HUA. The utility of orlistat as an adjunct therapy to prevent gout flares during weight loss in patients with HUA was emphasized.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05496075.

Relationship between serum uric acid in early pregnancy and gestational diabetes mellitus: a prospective cohort study

PURPOSE

The association between serum uric acid (UA) and gestational diabetes mellitus (GDM) was still unclear. Serum UA levels in pregnancy differed from that in non-pregnancy. This study aimed to investigate the changes of serum UA in early pregnancy, and to explore the association of serum UA with the risk of GDM.

METHODS

A prospective double-center study including 873 singleton pregnant women was conducted in Beijing, China since 2019 (clinical trial number: NCT03246295). Seventy-eight healthy non-pregnant women were selected to compare the changes of biomarkers in pregnancy. Spearman correlation and logistic regression analysis were performed to measure the relationship between serum UA in early pregnancy and GDM.

RESULTS

The incidence of GDM in our cohort was 20.27%(177/873). Compared with non-pregnant women, serum UA and creatinine decreased significantly during early pregnancy. Serum UA concentration in early pregnancy was significantly higher in GDM women than that in normal glucose tolerance (NGT) women [217.0(192.9, 272.0) μmol/l vs. 201.9(176.0, 232.0) μmol/l, p < 0.001]. After adjusted for confounding factors, elevated serum UA remained as an independent risk factor for GDM. The risk of GDM increased when serum UA was above 240 μmol/l (adjusted OR 1.964, 95% CI 1.296-2.977, p < 0.001), and stronger relationships between serum UA and GDM were observed in pregnant women aged over 35 years old and preBMI ≥ 24 kg/m2.

CONCLUSION

The normal range of serum UA and creatinine in pregnant women were lower than those in non-pregnant women. It is essential to monitor serum UA concentrations since early pregnancy to alert and prevent GDM, especially in older and heavier pregnant women.

CLINICAL TRIAL NUMBER

NCT03246295.

Association between anthropometric indices and hyperuricemia: a nationwide study in China

This article explored the relationship between anthropometric indices and hyperuricemia in Chinese adults. The ability of each anthropometric index to predict hyperuricemia was also compared in this article. This is a cross-sectional study containing 69,842 samples from 31 provinces and cities in China. Anthropometric indices included body mass index (BMI), waist circumference (WC), a body shape index (ABSI), body roundness index (BRI), waist-to-height ratio (WHtR), lipid accumulation product (LAP), visceral adiposity index (VAI), triglyceride-glucose index (TyG), waist circumference-triglyceride index (WTI), and weight-adjusted waist index (WWI). The survey data obtained were disaggregated and analyzed according to sex and age. BMI, WC, BRI, WHtR, LAP, VAI, TyG, WTI, and WWI were all significantly associated with hyperuricemia (P < 0.001). In the total population, WTI (AUC 0.7015, P < 0.001) had the highest predictive power, and WWI (AUC 0.5417, P < 0.001) had the lowest. In addition, after dividing the male and female populations, LAP (AUC 0.6571, P < 0.001 for men; AUC 0.7326, P < 0.001 for women) had the highest predictive power among both men and women. The ABSI (AUC 0.5189, P < 0.001 for men; AUC 0.5788, P < 0.001 for women) had the lowest predictive power among both men and women. BMI, WC, BRI, WHtR, LAP, VAI, TyG, and WTI were positively correlated with the risk of hyperuricemia and serum uric acid concentrations in both sexes. Among the general population, WTI had the highest predictive power. After dividing the population by sex, LAP had the highest predictive power in both men and women. Key Points • Anthropometric indices are highly correlated with hyperuricemia. Waist circumference-triglyceride index (WTI) is first found to be associated with hyperuricemia, and it has high predictive power. • The predictive power of anthropometric indices for hyperuricemia is more useful in women. • The restricted cubic splines visually shows the ratio of anthropometric indices to hyperuricemia ratio and the patient's serum uric acid concentration.

Relationship between abdominal circumference and the incidence of hyperuricemia in the general Japanese population

In this study, we aimed to separately evaluate the relationship between waist circumference and the incidence of hyperuricemia in men and women in the general Japanese population. We performed a population-based longitudinal study using data from the annual health examination of residents of Iki City, Japan. A total of 5567 participants without hyperuricemia at baseline were included in the analysis. The men and women were placed into groups according to the tertile of waist circumference. The outcome was incident hyperuricemia (uric acid > 416 µmol/L [7.0 mg/dL]). The relationship between waist circumference and the incidence of hyperuricemia was investigated using Cox proportional hazards models. During the follow-up period, hyperuricemia developed in 697 people (551 men and 146 women). The incidence (per 1000 person-years) of hyperuricemia increased with increasing waist circumference in the men (34.9 for tertile 1, 49.9 for tertile 2 and 63.3 for tertile 3; Ptrend < 0.001) and women (5.5 for tertile 1, 6.3 for tertile 2 and 11.9 for tertile 3; Ptrend < 0.001). Significant associations were identified after adjustment for potential confounders (men: Ptrend < 0.001; women: Ptrend = 0.014). In conclusion, both men and women with larger waist circumferences were at higher risks of subsequent hyperuricemia.

Serum uric acid did not affect embryonic and pregnancy outcomes in women without PCOS during IVF procedures

Objectives

Serum uric acid (UA) levels are associated with many systemic diseases. A previous study confirmed the association between high serum uric acid levels and poor prognosis of in vitro fertilization (IVF) treatment in polycystic ovary syndrome (PCOS) patients. This study aimed to explore the correlation between serum uric acid levels and reproductive outcomes in patients without PCOS.

Methods

A retrospective study that included 1057 patients who underwent pre-implantation genetic testing for monogenic disorders (PGT-M) treatment from January 2013 to December 2020 was conducted. The study population was further divided into 3 groups according to serum UA levels: the ≤250 μmol/L group, the 251-360 μmol/L group, and the >360 μmol/L group. The controlled ovarian hyperstimulation (COH) treatment outcomes, embryonic treatment outcomes and pregnancy outcomes of the first frozen embryo transfer (FET) cycle were compared among groups. Multivariable linear regression and binary regression were applied to detect the association between IVF outcomes and serum uric acid levels.

Results

The number of retrieved oocytes, fertilization rate, viable embryo rate, blastocyst formation rate and euploid rate were not associated with serum uric acid levels. The mature oocyte rate was negatively correlated with serum uric acid levels. The pregnancy outcomes of the first FET cycle were also not associated with serum uric acid levels. After adjustment for BMI, the perinatal outcomes were not associated with serum uric acid levels.

Conclusion

IVF treatment outcomes were not associated with serum uric acid levels in patients without PCOS.