Andrias davidianus bone peptides alleviates hyperuricemia-induced kidney damage in vitro and in vivo

Hyperuricemia(HUA)is a vital risk factor for chronic kidney diseases(CKD)and development of functional foods capable of protecting CKD is of importance.This paper aimed to explore the amelioration effects and mechanism of Andrias davidianus bone peptides(ADBP)on HUA-induced kidney damage.In the present study,we generated the standard ADBP which contained high hydrophobic amino acid and low molecular peptide contents.In vitro results found that ADBP protected uric acid(UA)-induced HK-2 cells from damage by modulating urate transporters and antioxidant defense.In vivo results indicated that ADBP effectively ameliorated renal injury in HUA-induced CKD mice,evidenced by a remarkable decrease in serum UA,creatinine and blood urea nitrogen,improving kidney UA excretion,antioxidant defense and histological kidney deterioration.Metabolomic analysis highlighted 14 metabolites that could be selected as potential biomarkers and attributed to the amelioration effects of ADBP on CKD mice kidney dysfunction.Intriguingly,ADBP restored the gut microbiome homeostasis in CKD mice,especially with respect to the elevated helpful microbial abundance,and the decreased harmful bacterial abundance.This study demonstrated that ADBP displayed great nephroprotective effects,and has great promise as a food or functional food ingredient for the prevention and treatment of HUA-induced CKD.

Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure

BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF.

Association Between Serum Uric Acid and Prevalence of Type 2 Diabetes Diagnosed using HbA1c Criteria Among Chinese Adults in Qingdao,China

Objective To determine whether elevated serum uric acid(UA)levels are associated with type 2 diabetes diagnosed using Hb A1 c levels among Chinese adults.Methods We conducted two population-based cross-sectional studies in Qingdao in China in 2006 and 2009.A total of 6894(39.4% men)subjects aged 35-74 years were included in the data analysis.Newly diagnosed diabetes was defined as Hb A1 c level of ≥6.5%,and prediabetes was classified as Hb A1 c level between 5.7% and 6.4% according to the International Diabetes Federation criteria.Multivariate logistic regression was employed to assess the association between UA and prevalence of type 2 diabetes defined using Glycated hemoglobin A1c(Hb A1 c levels.Results Subjects with prediabetes had higher UA levels than those with normal glucose tolerance,newly diagnosed diabetes,and known diabetes,with corresponding values of 325.1(82.5)μmol/L,310.9(84.2)μmol/L,291.3(81.7)μmol/L,305.2(83.6)μmol/L,respectively(P<0.001 for all comparisons).Binary logistic regression analysis showed that UA was a possible predictor for the prevalence of type 2 diabetes diagnosed using Hb A1 c levels,and the second quartile of UA levels had a higher odds ratio(OR:4.088;95% CI:2.900-5.765)for Hb A1 c than the other quartiles after adjusting for age,body mass index,sex,marital status,education,income,alcohol consumption,smoking,and cardiometabolic parameters.Conclusion Serum UA is significantly associated with type 2 diabetes diagnosed using Hb A1 c levels,independent of other cardiometabolic parameters.

Pharmacologic inducers of the uric acid exporter ABCG2 as potential drugs for treatment of gouty arthritis

Uric acid is the end product of purine catabolism and its plasma levels are maintained below its maximum solubility in water(6–7 mg/dl).The plasma levels are tightly regulated as the balance between the rate of production and the rate of excretion,the latter occurring in urine(kidney),bile(liver)and feces(intestinal tract).Reabsorption in kidney is also an important component of this process.Both excretion and reabsorption are mediated by specific transporters.Disruption of the balance between production and excretion leads to hyperuricemia,which increases the risk of uric acid crystallization as monosodium urate with subsequent deposition of the crystals in joints causing gouty arthritis.Loss-of-function mutations in the transporters that mediate uric acid excretion are associated with gout.The ATP-Binding Cassette exporter ABCG2 is important in uric acid excretion at all three sites:kidney(urine),liver(bile),and intestine(feces).Mutations in this transporter cause gout and these mutations occur at significant prevalence in general population.However,mutations that are most prevalent result only in partial loss of transport function.Therefore,if the expression of these partially defective transporters could be induced,the increased number of the transporter molecules would compensate for the mutation-associated decrease in transport function and hence increase uric acid excretion.As such,pharmacologic agents with ability to induce the expression of ABCG2 represent potentially a novel class of drugs for treatment of gouty arthritis.

Luteolin prevents uric acid-induced pancreatic β-cell dysfunction

Elevated uric acid causes direct injury to pancreatic β-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced β-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide （NO） formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor （NF）-κB. Western blotting assays were also performed to assess the effect of luteolin on the expression of MafA and inducible NO synthase （iNOS） in uric acid-treated cells. Finally, we evaluated the effect of luteolin on uric acidinduced inhibition of glucose-stimulated insulin secretion （GSIS） in Min6 cells and freshly isolated mouse pancreatic islets. We found that luteolin significantly inhibited uric acid-induced NO production, which was well correlated with reduced expression of iNOS mRNA and protein. Furthermore, decreased activity of NF-κB was implicated in inhibition by luteolin of increased iNOS expression induced by uric acid. Besides, luteolin significantly increased MafA expression in Min6 cells exposed to uric acid, which was reversed by overexpression of iNOS. Moreover, luteolin prevented uric acidinduced inhibition of GSIS in both Min6 cells and mouse islets. In conclusion, luteolin protects pancreatic β-cells from uric acid-induced dysfunction and may confer benefit on the protection of pancreatic β-cells in hyperuricemiaassociated diabetes.

Relationship of Uric Acid with Superoxide Dismutase (Sod) in Induced Hyperuricemic Rat Model

Increase uric acid levels have been found in oxidative stress. Urate radicals do not react with oxygen to form another peroxy radical, thus increasing the efficacy of uric acid as an antioxidant. Therefore, this study is designed to measure the level of uric acids and find out the relationship of uric acid with superoxide dismutase in induced hyperuricemic model. Forty male albino rats with an average weight of 180 ± 2 g were selected. The rats were grouped. The animals were fed on standard diet and given tap water ad libitum until treatment. Albino rats were divided into four groups. Group A(10)-control given only standard diet, group B(10) fed on 60% fructose with standard diet , group C(10) fed on fructose, standard diet and intraperitonially oxonic acid 250 mg/kg and group D (10) only on injection intraperotonially oxonic acid 250 mg/kg. At the end of study 10 mL of blood was drawn from heart of rats. Then blood was estimated for superoxide dismutase and uric acids done by kit methods randox-manual/Rx monza UA230/UA 233. Results: In Group C superoxide dismutase was found to be 32 % (244 mg/dL ± 2.23) more than control. In the same group the uric acid concentration was highly significantly correlated with control. Conclusion: The uric acid concentration increases when we take fructose up to 60% in our diet. It also increases superoxide dismutase concentration. More than this value may have inverse effect on the uric acid level and its role as an antioxidant may become inversed.

Status of Serum Uric Acid and Hyperuricemia among Adults in China:China Nutrition and Health Surveillance(2015)

Objective The purpose of this study was to determine the serum uric acid levels and the prevalence of hyperuricemia among Chinese adults in 2015 and compare the differences between urban and rural areas,as well as the differences between eastern,central,and western regions.Methods A national representative sample of 180,208 participants were included using a stratified,multistage,and random sampling method.The demographic characteristics and blood samples were collected to determine the serum uric acid levels and prevalence of hyperuricemia among subgroups using complicated sampling weight.A t-test or ANOVA was used for normally-distributed data.The Kruskal-Wallis rank test was used for skewed-distributed data.The Mantel-Haenszel chi-square test was used to compare the difference in categorical variables.Results The weighted mean uric acid level in Chinese adults was 310.4μmol/L(317.5μmol/L in urban areas and 302.9μmol/L in rural areas).The weighted average values of uric acid in eastern,central,and western China were 315.5μmol/L,303.5μmol/L,and 310.4μmol/L,respectively.The weighted prevalence of hyperuricemia in Chinese adults was 14.6%,with a prevalence of 16.5%in urban areas and12.5%in rural areas.The weighted prevalence of hyperuricemia in eastern,central,and western China was 16.0%,12.5%,and 14.8%,respectively.Conclusion The uric acid level in Chinese adults is relatively high.Effective actions are warranted to improve this metabolic abnormality.

Effect of dapagliflozin on uric acid in patients with chronic heart failure and hyperuricemia

BACKGROUND Patients with chronic heart failure(CHF)frequently develop hyperuricemia,an elevated serum uric acid level,associated with adverse outcomes.Dapagliflozin,a sodium-glucose cotransporter-2 inhibitor,demonstrates reduction in cardiovascular mortality and hospitalization in patients with CHF and ejection fraction(HFrEF),irrespective of diabetes.However,dapagliflozin’s effect on the uric acid levels in patients with CHF and hyperuricemia remain unclear.AIM To investigate the effects of dapagliflozin on uric acid levels in CHF patients with hyperuricemia.METHODS We conducted a randomized,double-blind,placebo-controlled trial in 200 patients with CHF and hyperuricemia,with HFrEF and serum uric acid levels≥7 mg/dL(≥416μmol/L).The participants were randomly assigned to receive a daily dose of 10 mg dapagliflozin or placebo for 24 months.The primary endpoint was the change in serum uric acid level from baseline to 24 months.Secondary endpoints included changes in left ventricular ejection fraction(LVEF),Nterminal pro-B-type natriuretic peptide(NT-proBNP),and quality of life(QoL)scores,as well as the incidence of cardiovascular death and hospitalization for heart failure.RESULTS At 24 months,dapagliflozin significantly reduced serum uric acid levels by 1.2 mg/dL(71μmol/L)compared with placebo(95%CI:-1.5 to-0.9;P<0.001).Dapagliflozin also significantly improved LVEF by 3.5%(95%CI:2.1-4.9;P<0.001),NT-proBNP by 25%(95%CI:18-32;P<0.001),and QoL scores by 10 points(95%CI:7-13;P<0.001)and reduced the risk of cardiovascular death and hospitalization for heart failure by 35%(95%CI:15–50;P=0.002)compared with the placebo.Adverse events were similar between the two groups,except for a higher rate of genital infections in the dapagliflozin group(10%vs 2%,P=0.01).CONCLUSION Dapagliflozin significantly lowered serum uric acid levels and improved the clinical outcomes in patients with CHF and hyperuricemia.Therefore,dapagliflozin may be a useful therapeutic option for this high-risk population.

Association between Serum Uric Acid to HDL-Cholesterol Ratio and Nonalcoholic Fatty Liver Disease Risk among Chinese Adults

Objective The aim of this case-control study was to explore the association between serum uric acid to high density lipoprotein cholesterol ratio(UHR) and the risk of nonalcoholic fatty liver disease(NAFLD) in Chinese adults.Methods A total of 636 patients with NAFLD and 754 controls were enrolled from the Affiliated Hospital of Qingdao University, China, between January and December 2016. All patients completed a comprehensive questionnaire survey and underwent abdominal ultrasound examination and a blood test. NAFLD was diagnosed using ultrasonography after other etiologies were excluded. Logistic regression and restricted cubic spline model were conducted to evaluate the relationship of UHR with NAFLD risk.Results The multivariable adjusted odds ratio(95% confidence interval, CI) for NAFLD in the highest versus lowest quartile of UHR was 3.888(2.324–6.504). In analyses stratified by sex and age, we observed significant and positive associations between UHR and the risk of NAFLD in each subgroup. In analyses stratified by body mass index(BMI), a significant and positive association was found only in individuals with a BMI of ≥ 24 kg/m2. Our dose-response analysis indicated a linear positive correlation between UHR and the risk of NAFLD.Conclusion UHR is positively associated with the risk of NAFLD and may serve as an innovative and noninvasive marker for identifying individuals at risk of NAFLD.

Analysis of Blood Lipids, Blood Glucose, Blood Uric Acid, and Blood Routine Test Results in Retired Employees of a Unit in the Civil Aviation System

Objective:To investigate and analyze the annual physical examination results of retired employees from a unit in the civil aviation system,focusing on blood lipids,blood glucose,blood uric acid,and blood routine results.The study aims to provide relevant references for formulating reasonable disease management measures for preventing and controlling hyperlipidemia,hyperuricemia,and other conditions in retired employees.Methods:The examination results of 231 participants were collected and analyzed.The participants were divided into four groups based on age:middle-aged group,young-old group,middle-old group,and old-old group.The blood test results were compared across these groups,and an assessment of atherosclerotic cardiovascular disease(ASCVD)risk levels was completed in conjunction with medical history.Blood test results were also compared by gender.Results:There were no significant statistical differences in blood test results when grouped by age.However,the prevalence of hyperuricemia was higher in males than in females,while the prevalence of hypercholesterolemia was higher in females than in males.The LDL-C target achievement rate was lower in the moderate-and-high-risk group as well as the very high-risk group as defined by ASCVD risk levels.Conclusion:Management of hyperuricemia and hyperlipidemia in retired employees(elderly patients)should be strengthened to reduce the risk of ASCVD events and alleviate the potential medical burden associated with disease progression.

Association between serum uric acid level and endothelial dysfunction in elderly individuals with untreated mild hypertension

Background Endothelial dysfunction is the initial stage in atherosclerotic formation and progression and is associated with high serum uric acid(SUA)level.We hypothesized that reactive hyperemia index(RHI),which reflects endothelial function,is associated with SUA levels in elderly individuals with untreated mild hypertension.Methods We recruited 123 patients≥60 years with untreated mild hypertension.The association between SUA level and RHI was analyzed using univariate correlation analysis and multiple regression analysis.The receiver operating characteristic(ROC)curve was performed to validate the cutoff value of SUA that can be used to predict endothelial dysfunction.Results The serum uric acid level significantly increased in the RHI<1.67 group,and this result was still observed in the subgroup of men.RHI was inversely associated with SUA level(P=0.006)and the association was still observed after adjusting for factors,such as age,sex,smoking status,and creatinine level(P=0.014).In the subgroup analysis,a positive association was observed only in men.In the ROC curve analysis,the optimal cutoff values of SUA for predicting endothelial dysfunction was 293.5μmol/L in elderly mild hypertension patients and 287.0μmol/L in men.Conclusion A high SUA level was considered an independent predictor of endothelial dysfunction among elderly individuals,particularly men with untreated mild hypertension.

A review: effect and mechanism of plant extracts rich in polyphenols on reducing uric acid activity

Hyperuricemia is a metabolic condition caused by the increase of uric acid level in the body,which can lead to gout,kidney disease,cardiovascular disease,hypertension and diabetes.In recent years,the incidence rate of hyperuricemia has been increasing and gradually becoming younger.Allopurinol and febuxostat are commonly used drugs to reduce the level of uric acid in the body.Although these drugs have good curative effect,they can produce adverse reactions.Therefore,it has been the focus of attention to find appropriate treatment and new drugs to reduce serum uric acid level.Natural plants have become the source of new drugs for their multiple biological activities,strong efficacy and minimal side effects.More and more studies have shown that natural plant extracts rich in phenols,flavonoids and other active components can significantly reduce the level of uric acid,and improve the complications caused by high uric acid.In this paper,hyperuricemia related diseases,functional plants rich in polyphenols with the effect of reducing uric acid and the mechanism of their active components were reviewed.

Serum uric acid level in newly diagnosed essential hypertension in a Nepalese population:A hospital based cross sectional study

Objective:To develop the missing link between hyperuricemia and hypertension.Methods:The study was conducted in Department of Biochemistry in collaboration with Nephrology Unit of Internal Medicine Department.Hypertension was defined according to blood pressure readings by definitions of the Seventh Report of the Joint National Committee.Totally 205newly diagnosed and untreated essential hypertensive cases and age-sex matched nonnotensive controls were enrolled in the study.The potential confounding factors of hyperuricemia and hypertension in both cases and controls were controlled.Uric acid levels in all participants were analyzed.Results:Renal function between newly diagnosed hypertensive cases and nonnotensive healthy controls were adjusted.The mean serum uric acid observed in newly diagnosed hypertensive cases and in nonnotensive healthy controls were(290.05±87.03)μmol/L and(245.24±09.38)μmol/L respectively.A total of 59(28.8%)participants of cases and 28(13.7%)participants of controls had hyperuricemia(odds ratio 2.555(95%CI:1.549-4.213),P<0.00l).Conclusions:The mean serum uric acid leveb and number of hyperuricemic subjects were found to be significantly higher in cases when compared to controls.

Serum Uric Acid is Associated with the Predicted Risk of Prevalent Cardiovascular Disease in a Community-dwelling Population without Diabetes

Objective To examine the association between serum uric acid levels and cardiovascular disease risk among individuals without diabetes.Methods We investigated the association between serum uric acid levels and the risk of prevalent cardiometabolic diseases, 10-year Framingham risk for coronary heart disease, and 10-year risk for atherosclerotic cardiovascular diseases （ASCVD） among 8,252 participants aged 〉 40 years without diabetes from Jiading district, Shanghai, China.Results Body mass index, waist circumference, blood glucose, glycated hemoglobin, blood pressure, and serum lipids increased progressively across the sex-specific quartiles of uric acid （all P trend 〈 0.05）. Compared with individuals in the lowest quartile, those in the higher quartiles had a significantly higher prevalence of obesity, hypertension, and dyslipidemia （all P trend 〈 0.05）. A fully adjusted logistic regression analysis revealed that individuals in the highest quartile had an increased risk of predicted cardiovascular disease compared with those in the lowest quartile of uric acid. The multivariate adjusted odds ratios （ORs） [95% confidence intervals （C/s）] for the highest quartiles for high Framingham risk were 3.00 （2.00-4.50） in men and 2.95 （1.08-8.43） in women. The multivariate adjusted ORs （95% C/s） for the highest quartile for high ASCVD risk were 1.93 [1.17-3.17） in men and 4.53 （2.57-7.98） in women.Conclusion Serum uric acid level is associated with an increased risk of prevalent obesity, hypertension, dystipidemia, 10-year Framingham risk for coronary heart disease, and lO-year risk for ASCVD among Chinese adults without diabetes.

Serum uric acid as a prognostic marker in the setting of advanced vascular disease： a prospective study in the elderly

Background Many epidemiological studies analyze the relationship between hyperuricemia and cardiovascular outcomes. This observational prospective study investigates the association of serum uric acid （SUA） levels with adverse cardiovascular events and deaths in an elderly population affected by advanced atherosclerosis. Methods Two hundred and seventy six elderly patients affected by advanced atherosclerosis （217 males and 59 females; aged 71.2 ±7.8 years） were included. All patients were assessed for history of cardiovascular disease, cancer, obesity and traditional risk factors. Patients were followed for approximately 31 ±11 months. Major events were recorded during follow-up, defined as myocardial infarction, cerebral isehemia, myocardial and/or peripheral revascularization and death. Results Mean SUA level was 5.47 ±1.43 mg/dL; then we further divided the population in two groups, according to the median value （5.36 mg/dL）. During a median follow up of 31 months （5 to 49 months）, 66 cardiovascular events, 9 fatal cardiovascular events and 14 cancer-related deaths have occurred. The patients with increased SUA level presented a higher significant incidence of total cardiovascular events （HR： 1.867, P = 0.014, 95% CI： 1.134-3.074）, The same patients showed a significant increased risk of cancer-related death （HR： 4.335, P = 0.025, 95% CI： 1.204-15.606）. Conclusions Increased SUA levels are independently and significantly associated with risk of cardiovascular events and cancer related death in a population of mainly elderly patients affected by peripheral vasculopathy.

Linking uric acid metabolism to diabetic complications

Hyperuricemia have been thought to be caused by the ingestion of large amounts of purines, and prevention or treatment of hyperuricemia has intended to prevent gout. Xanthine dehydrogenase/xanthine oxidase(XDH/XO) is rate-limiting enzyme of uric acid generation, and allopurinol was developed as a uric acid(UA) generation inhibitor in the 1950 s and has been routinely used for gout prevention since then. Serum UA levels are an important risk factor of disease progression for various diseases, including those related to lifestyle. Recently, other UA generation inhibitors such as febuxostat and topiroxostat were launched. The emergence of these novel medications has promoted new research in the field. Lifestyle-related diseases, such as metabolic syndrome or type 2 diabetes mellitus, often have a common pathological foundation. As such, hyperuricemia is often present among these patients. Many in vitro and animal studies have implicated inflammation and oxidative stress in UA metabolism and vascular injury because XDH/XO act as one of the major source of reactive oxygen species Many studies on UA levels and associated diseases implicate involvement of UA generation in disease onset and/or progression. Interventional studies for UA generation, not UA excretion revealed XDH/XO can be the therapeutic target forvascular injury and renal dysfunction. In this review, the relationship between UA metabolism and diabetic complications is highlighted.

Serum uric acid is a risk factor for large-artery atherosclerosis cerebral infarction

Using the Trial of Org 10172 in Acute Stroke Treatment （TOAST） classification for acute ischemic stroke, 371 patients with either acute large-artery atherosclerosis or small-artery oc-clusion cerebral infarction were recruited to investigate the potential impact of elevated serum uric acid on cerebrovascular disorders. The results showed that patients who have suffered from large-artery atherosclerosis, relative to small-artery occlusion patients, were characterized by elevated serum uric acid but reduced high-density lipoprotein cholesterol and triglyceride levels. Logistic regression showed that elevated uric acid and lower triglyceride levels were the main risk factors for patients with large-artery atherosclerosis. The findings of this study suggest that hyperuricemia may be a risk factor for stroke.

Electrochemical determination of vitamin C in the presence of uric acid by a novel TiO_2 nanoparticles modified carbon paste electrode

The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hydroquinone（BBNBH）.The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA,leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction.This modified electrode exhibits well-separated oxidation peaks for AA and uric acid（UA）.The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.

Science Letters:Evaluation of a kinetic uricase method for serum uric acid assay by predicting background absorbance of uricase reaction solution with an integrated method

A patented kinetic uricase method was evaluated for serum uric acid assay. Initial absorbance of the reaction mixture before uricase action （A0） was obtained by correcting the absorbance at 293 nm measured before the addition of uricase solution, and background absorbance （Ab） was predicted by an integrated method. Uric acid concentration in reaction solution was calculated from AA, the difference between A0 and Ab, using the absorptivity preset for uric acid. This kinetic uricase method exhibited CV〈4.3% and recovery of 100%. Lipids, bilirubin, hemoglobin, ascorbic acid, reduced glutathione and xanthine 〈0.32 mmol/L in serum had no significant effects. △A linearly responded to 1.2 to 37.5 μmol/L uric acid in reaction solution containing 15 μl serum. The slope of linear response was consistent with the absorptivity preset for uric acid while the intercept was consistent with that for serum alone. Uric acid concentrations in clinic sera by different uricase methods positively correlated to each other. By Bland-Altman analysis, this kinetic uricase method accorded with that by quantifying the total change of UV absorbance on the completion of uricase reaction. These results demonstrated that this kinetic uricase method is reliable for serum uric acid assay with enhanced resistance to both xanthine and other common errors, wider range of linear response and much lower cost.

Confounders of uric acid level for assessing cardiovascular outcomes

We read the article entitled Serum uric＇ acid as a prognostic marker in the setting of advanced vascular disease： a prospective study in the elderly by Stolfo, et al. with great interest. The authors evaluated the association of serum uric acid （SUA） levels with adverse cardiovascular events and deaths in an elderly population affected by advanced atherosclerosis. They founded meaningful association between SUA levels and of cardiovascular events and cancer related death. We believe that these findings will lead for further studies on uric acid.