Association of maternal serum uric acid levels with LBW/SGA: a large retrospective cohort study.

BACKGROUND: Elevated maternal serum uric acid (UA) levels were associated with adverse perinatal outcomes. This study aimed to examine the association between UA and the risk of low birth weight (LBW) / small for gestational age (SGA). METHODS: A cohort study of women delivered in Shanghai maternity hospital was included between 2017 and 2021. Electronic medical records were utilized to extract information and antenatal care records. The cut-off value of UA was 360 µmol/L. The outcome was LBW/SGA, with LBW defined as birth weight below 2500 g and SGA indicating birth weight below the 10th percentile of average weight for gestational age. The assessment of SGA was based on the Chinese standard curve for birth weight at various gestational ages. Univariate, multivariate logistic regression models, restricted cubic spline were used in this study, with adjustments made for confounding factors. RESULTS: Sixty-nine thousand six hundred seventy-four live births and singleton pregnancies were included. The ratio of LBW/SGA was 3.3%/9%. Maternal UA levels were significantly negatively correlated with birth weight. High UA levels were associated with high risk of LBW/SGA, especially in third trimester. In BMI < 25 group, the risk of LBW increased to 2.35-fold (95%CI, 1.66-3.31) in hyperuricemic group (UA > 360 µmol/L). The SGA risk was 1.66-fold (95%CI, 1.37-2.00). Gestational hypertension (GH) with hyperuricemica increased the risk of LBW (aOR = 4.00, 95%CI, 2.01-7.93) and SGA (aOR = 2.63, 95%CI, 1.83-3.78). Preeclampsia (PE) with hyperuricemia increased the risk of LBW (aOR = 1.38, 95%CI, 0.63-3.03) and SGA (aOR = 1.81, 95%CI, 1.18-2.78). In delivery gestational week (DGW) ≥ 37 group, if UA > 360 µmol/L, the incidence of LBW increased to 2.46-fold (95%CI, 1.62, 3.73) and the incidence of SGA increased to 1.52-fold (95%CI, 1.24, 1.87). In DGW < 37 group, if UA > 360 µmol/L, the incidence of LBW increased to 2.70-fold (95%CI, 1.92, 3.80) and the incidence of SGA increased to 2.13-fold(95%CI, 1.50, 3.02). CONCLUSIONS: The study found an inverse correlation between UA levels and birth weight. High UA levels were associated with increased risk of LBW/SGA, particularly in third trimester. GH or PE complicated by hyperuricemia were found to have significantly higher risk of developing LBW/SGA. This relationship also existed in pregnant women with BMI < 25.

The dysregulation of immune cells induced by uric acid: mechanisms of inflammation associated with hyperuricemia and its complications.

Changes in lifestyle induce an increase in patients with hyperuricemia (HUA), leading to gout, gouty arthritis, renal damage, and cardiovascular injury. There is a strong inflammatory response in the process of HUA, while dysregulation of immune cells, including monocytes, macrophages, and T cells, plays a crucial role in the inflammatory response. Recent studies have indicated that urate has a direct impact on immune cell populations, changes in cytokine expression, modifications in chemotaxis and differentiation, and the provocation of immune cells by intrinsic cells to cause the aforementioned conditions. Here we conducted a detailed review of the relationship among uric acid, immune response, and inflammatory status in hyperuricemia and its complications, providing new therapeutic targets and strategies.

Pathological social withdrawal in autism spectrum disorder: A case control study of hikikomori in Japan.

Introduction: Hikikomori, a form of pathological social withdrawal, has been suggested to have comorbidity with autism spectrum disorder (ASD). This study aimed to clarify how characteristics of ASD are associated with hikikomori. Methods: Thirty-nine adult male patients with a diagnosis of ASD attending our outpatient clinic for neurodevelopmental disabilities were subjected to a structured interview regarding social withdrawal, various self-administered questionnaires, and blood tests. Through structured interviews, the subjects were divided into two groups: (Group 1) ASD with hikikomori condition and (Group 2) ASD without hikikomori condition. Sixteen subjects qualified as hikikomori and 23 subjects qualified as subjects without hikikomori. Age, sex, autism spectrum quotient (AQ), Autism Diagnostic Observation Schedule (ADOS), and FIQ were matched. Results: Compared to non-hikikomori controls, hikikomori cases were likely to have stronger sensory symptoms, lower uric acid (UA) (p = 0.038), and higher rates of atopic dermatitis (p = 0.01). Cases showed more severe depressive and social anxiety symptoms based on self-rated scales: Patient Heath Questionnaire 9 (PHQ-9) (p < 0.001) and Liebowitz Social Anxiety Scale Japanese Version (LSAS-J) (p = 0.04). Tarumi's Modern-Type Depression Trait Scale (TACS-22), which measure traits of Modern-Type Depression (MTD), were significantly higher in cases (p = 0.003). Conclusion: The present study has suggested that ASD patients with hikikomori were more likely to have higher sensory abnormalities, comorbid atopic dermatitis, lower UA, stronger depressive, and anxiety tendency. Evaluating and approaching these aspects are important for appropriate interventions in ASD with hikikomori. Further investigations should be conducted to validate our pilot findings.

Purine signaling pathway dysfunction in autism spectrum disorders: Evidence from multiple omics data.

Introduction: Previous studies have suggested that the dysregulation of purine metabolism may be associated with autism spectrum disorder (ASD). Here, we adopted metabolomics and transcriptomics to verify and explore the underlying molecular mechanism of purine metabolism dysfunction in ASD and identify potential biomarkers within the purine metabolism pathway. Methods: Ultra-high-performance liquid chromatography-mass spectrometry was used to obtain the plasma metabolic profiles of 12 patients with ASD and 12 typically developing (TD) children. RNA sequencing was used to screen differentially expressed genes related to the purine metabolic pathway and purine receptor-coding genes in 24 children with ASD and 21 healthy controls. Finally, serum uric acid levels were compared in 80 patients with ASD and 174 TD children to validate the omics results. Results: A total of 66 identified metabolites showed significant between-group differences. Network analysis showed that purine metabolism was the most strongly enriched. Uric acid was one of the most highlighted nodes within the network. The transcriptomic study revealed significant differential expression of three purine metabolism-related genes (adenosine deaminase, adenylosuccinate lyase, and bifunctional enzyme neoformans 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) transformylase/inosine monophosphate (IMP) cyclohydrolase) (p < 0.01) and five purinergic receptor genes (P2X7, P2Y2, P2Y6, P2Y8, and P2Y10) (p < 0.05). In the validation sample, there was a significant difference in serum uric acid levels between the two groups (p < 0.001), and the area under the curve for uric acid was 0.812 (sensitivity, 82.5%; specificity, 63.8%). Discussion: Patients with ASD had dysfunctional purine metabolic pathways, and blood uric acid may be a potential biomarker for ASD.

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

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

Ultra-processed foods: Cross-sectional and longitudinal association with uric acid and hyperuricemia in ELSA-Brasil.

BACKGROUND AND AIMS: Food intake influences uric acid (UA) levels and hyperuricemia (HU), but evidence on the role of ultra-processed foods (UPFs) are scarce. The association between UPFs consumption and (1) HU prevalence and UA levels; (2) HU cumulative incidence; and (3) UA level change over a 4-year period was investigated. METHODS AND RESULTS: Cross-sectional and longitudinal analyses were performed using baseline (2008-2010, aged 35-74 years) and second visit (2012-2014) data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Participants with glomerular filtration rate <60 mL/min/1.73 m2, bariatric surgery, implausible caloric intake, and using urate-lowering therapy (ULT) at baseline were excluded (all analyses). Participants with HU at baseline were excluded from longitudinal analyses. UPFs consumption was assessed using a food frequency questionnaire (FFQ) and categorized by the NOVA classification system (100 g/day). HU was defined as UA≥6.8 mg/dL. Linear, logistic, and mixed-effect linear regressions investigated the associations between UPFs consumption and UA/HU, adjusted for covariates. The final samples included 13,923 (cross-sectional) and 10,517 (longitudinal) individuals. The prevalence of HU was 18.7%, and the cumulative incidence was 4.9%. Greater UPFs consumption was associated with a greater prevalence of HU (OR:1.025 95%CI: 1.006; 1.044) and higher UA levels (ß:0.024 95%CI: 0.016; 0.032). Every additional consumption of 100 g/day of UPFs raised the 4-year cumulative incidence of HU by 5.6% (95%CI: 1.021; 1.092). However, UPFs were not associated with the pace of UA level changes during the study period. CONCLUSION: The present study shows that greater UPFs consumption is associated with another deleterious health consequence: higher UA levels and the risk of having HU.

Serum uric acid level in chronic liver disease and its correlation with Child-Pugh score in a tertiary care hospital from South India.

Background: Chronic liver disease (CLD) is one of the important causes of morbidity and mortality in our country, and since the damage to the liver is irreversible, we have to look for many severity markers or predictors for the prognosis of the patient. In this study, we have tried to correlate the level of serum uric acid (UA) with the severity of CLD presented as a Child-Pugh score. Methods: A cross-sectional observational study was conducted at Vijayanagar Institute of Medical Science (VIMS), Ballari, Karnataka, from October 2015 to June 2017 in the Department of General Medicine. Fifty patients diagnosed with CLD, aged between 18 and 65 years, of either gender, were enrolled in the study. Serum UA levels were measured, and liver function and coagulation parameters were assessed. A statistical analysis was performed to evaluate the association between serum UA levels, liver function test, and coagulation parameters. Results: In our study, the mean serum UA level was 6.52 mg/dl and was raised in patients with CLD in correlation to its severity. Alcoholic liver disease (ALD) was the most common etiology for CLD (80%) followed by hepatitis B (Hep B) virus infection (12%) and hepatitis C (Hep C) virus infection (6%). Serum UA levels increased as the Child-Turcotte-Pugh (CTP) score increased. The mean UA level in CTP class C was 8.29 mg/dl. Various parameters such as serum aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase, total bilirubin, international normalized ratio (INR), calcium, and albumin were significantly associated with serum UA levels in CLD patients. Conclusion: The correlation between rising blood UA levels and the Child-Pugh score shows that UA estimate may be a valid and affordable indicator for assessing the extent of liver cirrhosis in CLD.

The influence of geographical environment factors on reference value of serum uric acid in healthy people based on CatBoost model and SHAP analysis / 西安交通大学学报(医学版)

【Objective】 To explore the geographical environment factors that may affect serum uric acid (UA) of healthy people and explore the change trend of UA reference value at the national scale. 【Methods】 The UA reference values of 607905 healthy people from 565 loci in China were collected, and the correlation between 25 geographical environment factors and UA reference values was analyzed by correlation analysis. CatBoost model was constructed and SHAP value interpretation model was applied to predict the UA reference values of healthy people in counties and cities in China, and the geographical distribution map of UA reference values of healthy people in China was drawn by using ordinary Kriging. 【Results】 A total of 20 indicators, namely, latitude, altitude, annual average temperature, annual average relative humidity, annual precipitation, air temperature annual range, annual average wind speed, percentage of surface soil silt, surface soil bulk density, surface soil gravel content, surface soil organic matter content, surface soil PH, surface soil (clay) cation exchange capacity, surface soil (silt) cation exchange capacity, surface soil base saturation, total surface soil exchange capacity, T-CaCO3, T-CaSO4, surface soil alkalinity, and surface soil salt showed their correlation with UA reference value of healthy people nationwide. The spatial distribution of UA reference values of healthy people across the country differed, manifested as the changing trend of higher in high altitude regions, higher in coastal regions than in inland regions, lower in the mid-eastern region, and higher in Southwest China at similar altitudes. 【Conclusion】 This study lays a foundation for further studies on the mechanism of different influencing factors on UA reference value. CatBoost model was established to provide the basis for establishing reference standards using UA reference values as prognostic factors for hyperuricemia and related chronic diseases in different regions.

Characterizing and Evaluating Diurnal Salivary Uric Acid Across Pregnancy Among Healthy Women.

Uric acid levels during pregnancy have been examined as a potential indicator of risk for gestational diabetes mellites, hypertension, and related adverse birth outcomes. However, evidence supporting the utility of serum uric acid levels in predicting poor maternal and fetal health has been mixed. The lack of consistent findings may be due to limitations inherent in serum-based biomeasure evaluations, such as minimal repeated assessments and variability in the timing of these assessments. To address these gaps, we examined repeated measurements of diurnal salivary uric acid (sUA) levels in a sample of 44 healthy women across early-mid and late pregnancy. We assessed potential covariates and confounds of sUA levels and diurnal trajectories, as well as associations between maternal weight gain and blood pressure during pregnancy and sUA concentrations. Using multilevel linear models, we found sUA increased across pregnancy and displayed a robust diurnal pattern with the highest concentrations at waking, a steep decline in the early morning, and decreasing levels across the day. Maternal pre-pregnancy BMI, age, prior-night sleep duration, and fetal sex were associated with sUA levels and/or diurnal slopes. Maternal blood pressure and gestational weight gain also showed significant associations with sUA levels across pregnancy. Our results expand upon those found with serum UA measurements. Further, they demonstrate the feasibility of using at-home, minimally-invasive saliva sampling procedures to track UA levels across pregnancy with potential applications for the long-term monitoring of maternal cardiometabolic risk.

Higher uric acid serum levels are associated with sarcopenia in west China: a cross-sectional study.

BACKGROUND: Sarcopenia is the decline in muscle strength and mass attributed to aging. The pathogenesis of sarcopenia may be triggered by oxidative stress and uric acid (UA) has strong antioxidant properties. The aim of this study was to investigate the relationship between UA and sarcopenia in community-dwelling adults of West China using the baseline data of West China Health and Aging Trend (WCHAT) study. DESIGN: A cross-sectional study. METHODS: 4236 adults aged 50 years or older in communities of west China were enrolled in this study. We applied Asian Working Group for Sarcopenia (AWGS) 2019 criteria to define sarcopenia. Muscle mass was measured using skeletal muscle index (SMI) based on bioimpedance analysis (BIA). Handgrip strength (HGS) and gait speed (GS) were recorded, respectively. Different variables like anthropometry measures, life styles, chronic disease and blood test were collected. General linear model was done to investigate the relationship between UA and HGS/GS/SMI, adjusting age, ethnic groups, sleeping quality, education level, cognitive function, smoking history, drinking history, ADL score, and chronic disease. RESULTS: Participants were grouped according to UA quartiles by gender. After adjusting for potential confounders, a negative association between serum UA levels and sarcopenia was shown both in men and women. And a significant association between serum UA levels and HGS in women was shown as an inverted J shape. Besides, a positive association between the UA quartiles and SMI was observed, irrespective of gender. CONCLUSIONS: Our results showed that higher uric acid levels were significantly correlated with higher muscle mass and grip strength among Chinese adults aged over 50. Higher UA serum levels might slow down the progression of sarcopenia.

Hyperuricemia as a possible risk factor for abnormal lipid metabolism in the Chinese population: a cross-sectional study.

BACKGROUND: Previous studies have reported that there may be a close relationship between elevated serum uric acid (UA) levels and metabolic syndrome. However, the association between these two factors has not been explored explicitly. Therefore, we carried out this study to investigate the association between UA and lipid profiles. METHODS: A total of 2,482 subjects participated in this cross-sectional study using a multistage stratified sampling method. Lipid profile, glucose metabolism, and other metabolic factors were measured and classified into UA-stratified and age-stratified groups to investigate the relationship between hyperuricemia and metabolic factors. Pearson correlations and logistic regressions were utilized to further explore the association between UA and lipid profile. RESULTS: The individuals aged 18 to 29 years presented with high serum UA concentrations. Moreover, the prevalence of hyperuricemia was higher among men than in women. Furthermore, statistically significant positive correlations were found between UA and serum triglycerides (TG), serum total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c). Conversely, only high-density lipoprotein cholesterol (HDL-c) was negatively correlated. Moreover, TG group status (1.70≤ TG <2.30 mmol/L) was an independent risk factor for hyperuricemia in both univariate and multivariate models. CONCLUSIONS: This study found significant positive associations between TG, TC, LDL, and UA but an inverse relationship with HDL-c. Thus hyperuricemia may be a risk factor for abnormal lipid metabolism.

Analysis of gender-specific associations between aldehyde dehydrogenase 2 (ALDH2) rs671 genetic polymorphisms and serum uric acid levels in Han Chinese.

BACKGROUND: Serum uric acid (SUA) is influenced by lifestyle and genetics, and unbalanced SUA levels are linked to various common disorders. While the aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism appears to be associated with SUA levels, the evidence remains inconclusive. The aim of this study was to examine the distribution of the ALDH2 rs671 polymorphism among Han Chinese in Beijing and determine the association between this polymorphism and SUA. METHODS: A total of 6,461 randomized healthy individuals were included in the study. Biochemical indicators were tested and ALDH2 rs671 polymorphism testing was conducted for subjects enrolled in the study. The distribution of the ALDH2 rs671 polymorphism and the relationship between genotype and the levels of serum lipids and uric acid (UA) were analyzed. RESULTS: The ALDH2 rs671 genotype frequencies were 68.1% (G/G), 29.3% (G/A), and 2.6% (A/A). There was no significant difference in allele distribution between males and females. In males, different ALDH2 genotypes exhibited significant differences in several biochemical analytes, including body mass index (BMI), blood glucose (Glu), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), UA, glutamyl transpeptidase (GGT), and creatinine (Cr) (P<0.05). No such differences were found in females. SUA levels in G/A and A/A-carrying males were significantly lower than those of G/G-carrying males. The effect of the ALDH2 polymorphism on UA was still significant after further adjustment for factors including BMI, Glu, TC, HDL-C, Cr, and GGT. CONCLUSIONS: The ALDH2 polymorphism is related to SUA in Beijing males, and A allele-carrying males have lower SUA levels.

A novel 3D coordination polymer constructed by dual-ligand for highly sensitive detection of purine metabolite uric acid.

Uric acid (UA), as the final product of purine metabolism, exists in urine and serum, which plays an important role in human metabolism, immunity and other functions. The sensitive, efficient, and rapid detection of UA has far-reaching significance in clinical diagnosis and disease prevention. Herein, a novel coordination polymer constructed by dual-ligand was successfully prepared, which exhibited excellent thermal and water stability. The polymer was interlaced by coordination bonds and hydrogen bonds to form an infinitely extended three-dimensional framework, which showed a rare and novel topological structure. The complex selectively recognized UA through significant fluorescence quenching response in the presence of various interferences. The excellent detection sensitivity (the limited detection of 1.2 µM), outstanding anti-interference ability and remarkable recyclability marked the complex to be a promising sensor material towards UA. In addition, the detection mechanism of UA by the complex was investigated in detail by combining density functional theory (DFT) and a variety of other analytical methods.

Correlation between the elevated uric acid levels and circulating renin-angiotensin-aldosterone system activation in patients with atrial fibrillation.

BACKGROUND: The aim of the present study was to investigate the correlation between the elevated uric acid (UA) levels and activation of the circulating renin-angiotensin-aldosterone system (RAAS) in patients with atrial fibrillation (AF). METHODS: A total of 233 outpatients and inpatients of the Cardiology Department from January 1, 2019, to December 31, 2019, were selected and divided into the sinus rhythm group (SR) with 84 cases, the paroxysmal AF group (pAF) with 76 cases, and the persistent AF group (PAF) with 73 patients. The general clinical data and the serum levels of UA of the enrolled patients were collected, and the radioimmunoassay was adopted to detect the levels of renin (Renin), angiotensin II (Ang II), and aldosterone (Ald). RESULTS: Renin, AngII, Ald, and UA in the PAF group were significantly higher than those in the pAF group, and the levels of the above indicators in the pAF group were significantly higher than those in the SR group (P<0.001). The left atrium anteroposterior diameter (LAD) and the left ventricular end-diastolic diameter (LVEDD) were significantly increased in the PAF group (P<0.001). The Pearson correlation analysis showed that the levels of the high sensitivity C-reactive protein (hsCRP), AngII Renin, Ald, LVEDD, and LAD were positively correlated with the serum levels of UA (r=0.174, 0.273, 0.34, 0.385, 0.138, respectively, P<0.05 in all). The left ventricular ejection fraction (LVEF) was negatively correlated with the UA level (r=-0.177, P<0.05). Multiple linear regression analysis showed that UA (ß=0.103) and LAD (ß=2.162) were independent risk factors for Renin. The independent risk factor for Ang II was UA (ß=0.167). The independent risk factor for Ald was UA (ß=0.283) and LAD (ß=8.721) (P<0.05). CONCLUSIONS: Elevated UA might cause excessive activation of the RAAS, aggravate the oxidative stress, and participate in the atrial remodeling, thereby promoting the occurrence and persistence of AF.

Survey on uric acid in Chinese subjects with essential hypertension (SUCCESS): a nationwide cross-sectional study.

BACKGROUND: Hyperuricemia (HUA) is associated with hypertension and increased cardiovascular risk. Current data regarding the prevalence of HUA in Chinese hypertensive patients are lacking. Our study aims to explore the prevalence and determinants of HUA in Chinese hypertensive adults. METHODS: Treatment-naive hypertensive adults or those taking single antihypertensive agent were included in a nationwide cross-sectional study. Basic demographics, antihypertensive medications, serum uric acid (UA), and other parameters were documented. RESULTS: The overall prevalence rate of HUA was 38.7% among 33,785 valid cases, 35.1% for males (UA >420 µmol/L), and 45.2% for females (UA >360 µmol/L). A multiple logistic regression analysis, adjusted for demographic and clinical factors (model 1), revealed that female sex [odds ratio (OR), 95% CI, 1.43, 1.36-1.51], age of ≥65 years (1.12, 1.05-1.19), low evaluated glomerular filtration rate [eGFR; 2.06, 1.91-2.23, the lowest [Q1] vs. the highest quartile (Q4)], unmarried (1.58, 1.10-2.27), Western China residency (3.21, 3.33-3.91), longer hypertension duration (1.97, 1.78-2.12, Q4 vs. Q1) and aspirin use (1.21, 1.14-1.29) were associated with HUA. In a multiple logistic regression analysis adjusted for clinical and metabolic parameters (model 2), female sex (OR, 95% CI, 1.34, 1.27-1.41), age of ≥65 years (1.09, 1.03-1.16), low eGFR (2.35, 2.19-2.52, Q1 vs. Q4), new-onset hypertension (2.01, 1.73-2.33), higher quartile of fasting blood glucose (FBG), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) levels, and body mass index (BMI) were associated with higher risk of HUA (1.89, 1.76-2.03; 2.15, 1.99-2.31; 2.86, 2.67-3.06; 1.27, 1.27-1.36, respectively, Q4 vs. Q1). Losartan, valsartan, and nifedipine were associated with lower risk of HUA (OR, 95% CI, 0.77, 0.67-0.88, 0.68, 0.60-0.77; 0.87, 0.77-0.99, 0.79, 0.70-0.89 and 0.80, 0.70-0.91, 0.82, 0.72-0.92), respectively, in models 1 and 2. CONCLUSIONS: The prevalence rate of HUA in Chinese hypertensive patients was 38.7%. Female sex, aging (≥65 years), and low eGFR were independent predictors of HUA. HUA was lower among the patients who were taking losartan, valsartan, and nifedipine. Western region residents, new-onset hypertension, longer hypertension duration, aspirin use, higher FBG, TG, LDL-C levels and BMI were potential risk factors for HUA.

Association between the uric acid and hypertension in community-based Chinese population: stratified analysis based on body mass index and age.

Many studies have shown that uric acid was related to hypertension. However, the association dependence on body mass index (BMI) or age was unclear. This study was performed with a group of 4012 Chinese population aged 30 to 92 years old. Subjects were divided into four groups according to the quartiles of uric acid (UA) concentration [First group: ≤ 231 µmol/L (reference), Second group: 231-289 µmol/L, Third group: 289-362 µmol/L, Fourth group: > 362 µmol/L]. Hypertension was defined as newly measured blood pressure ≥ 140/90 mmHg or taking antihypertensive drugs. Stratified analysis based on BMI (< 28 kg/m2 vs ≥ 28 kg/m2) and age (< 60 years old vs ≥ 60 years old) to analyze the association between UA and hypertension. Subjects were 54.50 (45.00, 63.00) years old, and 40.98% were male, 38.33% were hypertension. Adjusted odds ratios (95% confidence intervals) for the association of UA and hypertension were 2.226 (1.662, 2.980), 4.340 (3.253, 5.790), 5.898 (4.434, 7.845) and 6.557 (4.927, 8.727) in the four groups among ≥ 60 years old respectively comparing with first group among < 60 years old. Adjusted odds ratios (95% confidence intervals) for the association between UA and hypertension were 2.170 (1.236, 3.808), 5.260 (3.267, 8.468), 9.056 (5.509, 14.888) and 3.730 (2.529, 5.550) in the four groups among BMI ≥ 28 kg/m2 respectively comparing with first group among BMI < 28 kg/m2. Uric acid was significantly associated with the hypertension. The association was stronger among subjects ≥ 60 years old or BMI ≥ 28 kg/m2.

Higher Blood Uric Acid in Female Humans and Mice as a Protective Factor against Pathophysiological Decline of Lung Function.

The oxidant/antioxidant imbalance plays a pivotal role in the lung. Uric acid (UA), an endogenous antioxidant, is highly present in lung tissue, however, its impact on lung function under pathophysiological conditions remains unknown. In this work, pharmacological and genetic inhibition of UA metabolism in experimental mouse models of acute and chronic obstructive pulmonary disease (COPD) revealed that increased plasma UA levels improved emphysematous phenotype and lung dysfunction in accordance with reduced oxidative stress specifically in female but not in male mice, despite no impact of plasma UA induction on the pulmonary phenotypes in nondiseased mice. In vitro experiments determined that UA significantly suppressed hydrogen peroxide (H2O2)-induced oxidative stress in female donor-derived primary human bronchial epithelial (NHBE) cells in the absence of estrogen, implying that the benefit of UA is limited to the female airway in postmenopausal conditions. Consistently, our clinical observational analyses confirmed that higher blood UA levels, as well as the SLC2A9/GLUT9 rs11722228 T/T genotype, were associated with higher lung function in elderly human females. Together, our findings provide the first unique evidence that higher blood UA is a protective factor against the pathological decline of lung function in female mice, and possibly against aging-associated physiological decline in human females.

Interactions among endotoxin, uric acid, and lactate in relation to the risk of type 2 diabetes: A population-based study.

BACKGROUND: Blood levels of endotoxin, uric acid (UA), or lactate (LAC) are associated with type 2 diabetes mellitus (T2DM). Thus, we explored the interactions among blood endotoxin, UA, and LAC levels and the risk of T2DM. METHODS: This population-based cross-sectional study included 2520 Chinese adults. Fasting blood endotoxin, UA, and LAC levels were determined and the cut-off values were obtained from the receiver operating characteristic curve analysis. The study population was classified into two or four subgroups based on low or high, or both low and high levels of endotoxin, UA, and LAC, respectively. RESULTS: The odds ratios (ORs) for T2DM (all P < .05) were higher in the high groups than the low groups of endotoxin, UA, or LAC, respectively. Participants in the groups with high levels of both endotoxin and UA, endotoxin and LAC, or UA and LAC, had 4.71 (95% CI 3.01-7.37), 5.13 (95% CI 3.29-7.99), or 3.73 (95% CI 2.34-5.94) times higher risk for T2DM compared to those in groups with low levels of both endotoxin and UA, endotoxin and LAC, or UA and LAC (all P < 0.05), respectively. In the interaction analysis, an interactive effect between endotoxin and UA (P < .05), or endotoxin and LAC (P < .05), but not UA and LAC, was observed that contributed to an increased risk of T2DM. CONCLUSIONS: The interaction between levels of endotoxin and UA or levels of endotoxin and LAC was related to an increased risk of T2DM in the Chinese population.

Cross-sectional analysis of the association between serum uric acid levels and handgrip strength among Chinese adults over 45 years of age.

BACKGROUND: Sarcopenia is the decline in muscle strength and mass attributed to aging. The pathogenesis of sarcopenia may be triggered by oxidative stress; uric acid (UA) has strong antioxidant properties. This study aimed to examine if the serum UA level is associated with handgrip strength (HGS), which is a useful indicator of sarcopenia among Chinese participants aged over 45. METHODS: Our study included 992 eligible participants (583 males and 409 females). Based on serum UA quartiles and gender, the participants were divided into 8 groups. HGS was measured in kilograms using an electronic dynamometer. Face-to-face visits and fasting blood analyses were performed to determine the serum UA levels and various covariates. Univariate analysis of variance (ANOVA) and covariance (ANCOVA) was conducted to analyze the linear or quadratic trend between the UA levels and grip strength. RESULTS: Participants were grouped according to UA quartiles by gender. In both genders, ANOVA showed an inverted J-shaped association between serum UA levels and HGS (P for quadratic trend =0.004 in men, P for quadratic trend =0.003 in women). After adjusting for potential confounders, the association between the UA quartiles and HGS was unchanged, irrespective of gender. CONCLUSIONS: The results suggest that a specific range of serum UA levels may be associated with better HGS among Chinese adults aged over 45.

Mechanistic Insights of Soluble Uric Acid-related Kidney Disease.

Hyperuricemia, defined as the presence of elevated serum uric acid (sUA), could lead to urate deposit in joints, tendons, kidney and other tissues. Hyperuricemia as an independent risk factor was common in patients during the causation and progression of kidney disease. Uric acid is a soluble final product of endogenous and dietary purine metabolism, which is freely filtered in kidney glomeruli where approximately 90% of filtered uric acid is reabsorbed. Considerable studies have demonstrated that soluble uric acid was involved in the pathophysiology of renal arteriolopathy, tubule injury, tubulointerstitial fibrosis, as well as glomerular hypertrophy and glomerulosclerosis. In the review, we summarized the mechanistic insights of soluble uric acid related renal diseases.