Measurement Of Uric Acid Research Articles

Elevated Uric Acid Is Associated With New-Onset Atrial Fibrillation: Results From the Swedish AMORIS Cohort.

Background The role of uric acid is gaining increasing importance in the evaluation of cardiovascular disease, but its relationship with atrial fibrillation (AF) is unclear. This study aims to investigate the association between uric acid levels and risk of new-onset AF. Methods and Results A total of 339 604 individuals 30 to 60 years of age and free from cardiovascular disease at baseline (1985-1996) in the Swedish AMORIS (Apolipoprotein-Mortality Risk) cohort were followed until December 31, 2019 for incident AF. Cox regression models were used to examine the association between uric acid and AF, adjusting for potential confounders and stratifying by incident cardiovascular disease. Over a mean follow-up of 25.9 years, 46 516 incident AF cases occurred. Compared with the lowest uric acid quartile, each of the upper 3 quartiles were associated with an increased risk of AF in a dose-response manner. Adjusted hazard ratios were 1.09 (95% CI, 1.06-1.12) for second quartile, 1.19 (95% CI, 1.16-1.23) for third quartile, and 1.45 (95% CI, 1.41-1.49) for fourth quartile. The association was similar among individuals with and without incident hypertension, diabetes, heart failure, or coronary heart disease. The dose-response pattern was further supported in a subsample of individuals with repeated measurements of uric acid. Conclusions Elevated uric acid was associated with an increased risk of AF, not only among people with cardiovascular disease and cardiovascular risk factors but also among those without. Future investigations are needed to examine whether lowering uric acid is relevant for AF prevention.

A Cross-Sectional Study of Association between Serum Uric Acid Levels and Smoking in Chronic Smokers in a Tertiary Care Hospital

Background: Smoking is harmful and causes various diseases due to the accumulation of free radicals causing oxidative damage. Antioxidants help in resisting damage from oxidative stress resulting from cigarette smoking. The presence of the double bonds in the uric acid makes it a powerful antioxidant. Uric acid measurement is cheap, and hence, it can be used as a periodical screening tool for ensuring the adequate antioxidant activity. Objectives: To study the relationship between serum uric acid level and smoking in chronic smokers. Materials and Methods: This is a cross-sectional study among 110 smokers of age group between 28 and 60 years. A complete detailed history was obtained from subjects including age, sex, average number of daily cigarettes smoked, duration of smoking, and dietary habit. After examination, the attained subjects’ serum uric acid level were assessed. Results: Average number of cigarettes smoked (cigarettes/day) and Pack years of smoking have a significantly negative correlation with serum uric acid (mg/dL) and are not correlated with the duration of the smoking. The correlation of serum uric acid with the Pack years of smoking was significant within the age groups and with different dietary patterns, and not with the gender. Linear regression model predicts that serum uric acid (mg/dL) decreases −0.09 times for each unit increase in Pack years of smoking and is statistically significant. Conclusion: Cessation of smoking can be recommended among the smokers, to maintain the normal serum uric acid, as uric acid is responsible for the major antioxidant activity in the body, to prevent cancers.

PS-C27-11: HYPERTENSION AND LOW EGFR AMONG MALE OCCUPATIONAL AUTO-RICKSHAW DRIVERS FROM NORTH INDIA- SCREENING FOR CHRONIC KIDNEY DISEASE RISK FACTORS

Objective: To find out the prevalence of low estimated Glomerular Filtration Rate (eGFR) and major Chronic Kidney Disease (CKD) risk factors such as hypertension, Diabetes Mellitus, obesity among male occupational auto-rickshaw drivers as they are highly exposed to air pollution. Design and method: The study population included male auto-rickshaw drivers of more than or equal to 18 years of age and driving for at least one year. Participant's demography (height, weight, waist circumference), and blood pressure were measured and medical history, history of substance abuse, and occupation history was obtained in a structured questionnaire. Blood and urinalysis were performed for measurement of serum creatinine, uric acid, and proteinuria respectively. eGFR was measured using the CKD-EPI equation. Results: A total of 900 male auto-rickshaw drivers were enrolled in the study. Age varied from 19 to 75 (mean 39.56 ± 10.5 years). 59.6% had less than 15 years of experience in driving an auto-rickshaw (mean 13.1 ± 9.7 years) with daily working hours of 10.3 ± 2.1. Among 900 participants, 3.9% had low eGFR (less than 60 ml/min), and 8.7% had proteinuria (more than 30 mg/dl). Prevalence of CKD, hypertension, and diabetes was found to be 3.9% (stage - 1 to stage - 4; 6.4%, 1.3%, 3.4%, 0.5% respectively), 37% and 8.4% respectively. One-third (33.6%) of auto-rickshaw drivers were newly diagnosed with hypertension and 15 (2.7%) were new-onset diabetic. Around one-fourth (24.5%) of autorickshaw drivers were prevalent with hyperuricemia (serum uric acid more than 7 mg/dl) and 5% were anemic (Hb (less than 13 gm/dl). Approximately 42% of the participants were overweight or obese (BMI more than 25 kg/m2) and central obesity was found in 7.4% (more than 102 cm) participants. Tobacco products and alcohol use among auto/taxi drivers were high (63% and 23.5% respectively). Conclusion: High prevalence of CKD and associated risk factors such as hypertension, diabetes, obesity hyperuricemia, and anemia were observed in male occupational auto-rickshaw drivers. A routine screening program should be implemented for primary prevention and management of risk factors of CKD among such populations that are highly exposed to air pollution.

Odds of Achieving Target Serum Uric Acid Levels Among Gout Patients: The Role of Rurality in Outcomes and Treatment Adherence.

The goal of this paper was to analyze patient outcomes related to gout treatment including, serum uric acid (sUA) measures and treatment adherence across patients in metropolitan, micropolitan or rural counties. We conducted a drug-disease cohort study among patients with gout initiating urate lowering therapy. The proportion of patients with sUA < 6 mg/dL at 1 year of follow-up is compared over the cohort groups using a chi-square test and adjusted logistic regression. Adherence to urate lowering therapy was calculated using the proportion of days covered (PDC). A T-test was used to compare the average PDC and an adjusted logistic regression model was used to estimate the odds of a PDC greater than 80%. A total of 9922 patients were included in the study. Most patients were in a metropolitan (77.4%) area, followed by micropolitan (11.8%) and finally, (10.8%) in a rural area. We found no statistically significant difference among the proportion of patients achieving target sUA of <6 mg/dL, 37.17% among metropolitan patients, 38.9% among micropolitan patients, and 37.7% for those in a rural area, P-value = .502. The proportion of patients achieving 80% treatment adherence was 49.92% in the metropolitan, 51.78% in the micropolitan, and 55.05% in the rural areas, P-value = .005. Adjusted regression models showed no statistically significant difference in proportions achieving target sUA levels or 80% adherence. Urban patients treated for gout did not have better gout outcomes compared to rural patients. Future research should consider provider-based interventions to improve outcomes.

The glucocerebrosidase mutations and uric acid levels in Parkinson’s disease: A 3-years investigation of a potential biomarker”

BackgroundBlood uric acid level indicates an emerging biomarker in Parkinson's disease (PD). This study aimed to evaluate longitudinal uric acid levels among different kinds of glucocerebrosidase (GBA) mutations and to compare it among sporadic PD, genetic cohort Parkinson's disease (GENPD), genetic cohort unaffected (GENUN), and healthy control (HC) patients. MethodsWe conducted a study on 654 individuals from the Parkinson's progression markers initiative (PPMI) database. Baseline characteristics, uric acid levels, movement disorder society unified Parkinson's disease rating scale III (MDS-UPDRS III), Hoehn and Yahr Parkinson stage (H&Y stage), and DaT scan specific binding ratio (SBR) data were obtained. Different GBA mutations were collected and categorized into three groups. Longitudinal measurements of uric acid and MDS-UPDRS III score were evaluated during 3-years of follow-up. ResultGENPD cohort exhibited a greater MDS-UPDRS III score, H&Y stage, and lower SBR in the right caudate, left caudate, and right putamen compared to sporadic PD. Baseline uric acid level was similar among all groups and different GBA variants. After adjustment for age, sex, and body mass index, the uric acid level was significantly lower in the GENPD group than in HC during year 2 (P-value: 0.009). No significant longitudinal differences were detected for the MDS-UPDRS III score and three groups of GBA mutations. ConclusionThis is the first study to assess uric acid levels and MDS-UPDRS III scores among different GBA mutation variants within 3 years of follow-up. We found similar clinical characteristics among different subtypes of GBA mutations.

Deposition of Ni/RGO nanocomposite on conductive cotton fabric as non-enzymatic wearable electrode for electrochemical sensing of uric acid in sweat

In this work, the development of a wearable electrochemical sensor for the direct measurement of uric acid in human sweat is reported. The preparation of Ni and reduced graphene oxide composites with stable electrocatalytic responses, as well as their structural characterization, was carried out. The electrochemical properties of the Ni/RGO/CCF modified electrode of conductive cotton fabric were investigated for the purpose of uric acid determination using differential pulse voltammetry. On a scale ranging from 10 μM to 60 μM, the electrode signals (Ni/RGO/CCF) were found to be linearly related to the uric acid concentration. It was possible to attain a low limit of detection (5.083 μM) with good reproducibility. Finally, an interference investigation and real-time sample analysis of the modified electrode demonstrate that it has a great potential for use as disposable sensors in biological systems. • A wearable electrochemical sensor for the direct measurement of uric acid (UA) in human sweat is reported. • The fabricated electrode is investigated for the purpose of UA determination using differential pulse voltammetry. • The fabricated sensing electrode exhibits a great potential for use as disposable sensors in biological systems.

Determination of Cystatin C Level in a Sample of Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) effects around one-third of the population and is frequently under recognized by patients and clinicians. GFR of less than 60 mL/min/1.73 m2, A minimum of 30 mg of albuminuria per 24 hours, Hematuria or structural abnormalities are signs of kidney damage such like polycystic kidney disease or dysplastic kidneys that persists for more than 3 months. The purpose of this research was to examine the efficacy of cystatin C as a measure of renal function in individuals. Cystatin C, Creatinine, urea, and uric acid levels were measured in 225 blood samples (150 patients and 75 controls). Cystatin C was measured as enzymatic link absorbance assay and the measurements of urea, creatinine, and uric acid were performed using the Cobas c311. Cystatin C levels, urea, serum creatinine, and uric acid were found to show high significant differences (p &lt;0.01) between the patient and control. Cystatin C is useful to detect individuals with CKD who show a little reduction in GFR as compared to serum creatinine. Serum Cystatin C, urea, uric acid, and Creatinine levels all rise as eGFR falls. Serum Cystatin C could be utilized to evaluate people who have poorly managed diabetes mellitus or high blood pressure when the serum creatinine level is inconclusive.

Effect of Telmisartan and Quercetin in 5 Fluorouracil-Induced Renal Toxicity in Rats.

The present study was designed to evaluate the possible synergistic effects of telmisartan and quercetin in 5 fluorouracil (5-FU) induced nephrotoxicity in rats. Forty male rats were randomly divided into five groups: The negative control group, the positive control group that received 5-FU, the telmisartan group, receiving 10 mg/kg, the quercetin group, receiving 80 mg/kg, and the combination of telmisartan and quercetin group. All the treatments were given orally for 14 days. A single intraperitoneal injection of 5-FU (150 mg/kg) on day 13 of the experiment was given except for the negative control group. On the 15th day after scarification, approximately 5 mL of blood was collected and used for measurement of CBC, urea, creatinine, and uric acid. The kidneys were used for histopathological examination and for the measurement of kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), Cystatin C (Cys-C), and total antioxidant capacity (TAOC). The combination therapy significantly attenuated the levels of tissue KIM-1, NGAL, Cys-C, and serum uric acid as well as blood inflammatory markers, Neutrophil/Lymphocyte (NLR), Monocyte/Lymphocyte (MLR), and Platelets/Lymphocyte ratios (PLR), and restored the TAOC. The histopathological findings greatly support the biochemical tests. The results strongly suggest the renoprotective effects of telmisartan and quercetin in combination against the nephrotoxic effect of 5-FU through decreasing the levels of KIM-1, NGAL, and cys-C, and the novel inflammatory markers of kidney injury like NLP, MLR, and PLR, as well as decreasing uric acid and restoring the TAOC. The proposed mechanism could be the additive inhibitory effect on RAS provided by both telmisartan and quercetin.

Deep eutectic solvent-driven self-assembly of metal mercaptide complexes with enzyme-mimicking activities for detection of uric acid through one-step cascade catalytic reaction

This work presents a generic strategy to create a series of metal mercaptides complexes via coordination self-assembly between transition metals (Mn, Cu, Co, Fe, and Ni) and cysteine (Cys) by forming the sulfur-metal bridges. This strategy involves dissolving metal chlorides and Cys into deep eutectic solvents (DES), followed by the precipitation of metal mercaptides complexes (such as Cys-Mn) by adding water as an antisolvent, where DES serves as the solvent, shape directing, and capping agent, thereby preventing the formation of other metal impurities. Interestingly, the prepared complexes possess both laccase and peroxidase-like properties, allowing the design of a technique for the detection of L-3,4-dihydroxyphenylalanine (l-DOPA) and uric acid, respectively. The prepared Cys-Mn can linearly oxidize l-DOPA with its concentrations from 0.1 to 130 μM and the detection limit was calculated to be 75.5 nM. Additionally, the Cys-Mn can mimic the activity of peroxidase towards oxidization of o-phenylenediamine at neutral pH, allowing single-step and one-pot cascade reactions for visual and fluorometric measurements of uric acid (UA) that could work in the range of 0.2–500 μM UA with a detection limit of 0.06 μM and 0.054 μΜ, respectively. The assay was successful in detecting UA in serum and urine samples with relative standard deviation (RSD) ranging from 7.3% to 10.2% and 3.0%–8.5% respectively, suggesting that it may prove useful in medical diagnostic testing.

Hyperuricemia: an unrecognized risk factor for kidney-related sequelae in children with hemolytic uremic syndrome.

Chronic kidney-related sequelae after STEC-HUS occur in 20-40% of patients. Hyperuricemia (HU) may cause acute and chronic toxicity involving the kidneys. We retrospectively assessed if there was an association between the presence of HU during the acute illness and that of kidney-related sequelae in children with STEC-HUS. Children with STEC-HUS who had clinical and laboratory data at 2years of follow-up were included in this case-control study. Univariate and multivariate analyses were performed between patients with (cases) or without (controls) kidney-related sequelae to identify factors associated with outcomes, including different measures of serum uric acid (sUA) (baseline level, peak, and duration of HU). HU was defined as sUA > 8mg/dL. Of 86 patients included, 77.9% had HU. Patients with sequelae (n = 41) had a higher prevalence of HU (41/41 vs. 26/45, p < 0.01), higher baseline leukocyte count, serum creatinine (sCr), and sUA levels as well as lower sodium than controls. During hospitalization, cases also had higher sCr peak, sUA peak and duration of HU, requirement and duration of dialysis, extrarenal complications, and hypertension. By multivariate analysis, after adjusting for length of dialysis, only duration of HU (p = 0.0005; OR 1.7, 95% CI 1.27-2.36) remained as an independent predictor of sequelae, with a best cutoff of 5.5days (AUC 0.95, specificity 80%, sensitivity 100%). The presence of HU is a common finding in children with STEC-HUS and its duration during the acute stage was associated with kidney-related sequelae, regardless of the duration of dialysis. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Measurement of serum uric acid by isotope dilution liquid chromatography tandem mass spectrometry: Modification of a candidate reference measurement method and its clinical application

Uric acid is a precipitating factor for gout and renal disease, and regular monitoring of uric acid concentration is essential for health management. Hence, accurate measurement is indispensable for clinical diagnosis. Reference measurement procedure (RMP) is an essential element to ensure accuracy and comparability of tested results. In this study, the optimization of a candidate RMP (cRMP) adopting isotope dilution coupled with liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method for human serum uric acid measurement has been developed. The accuracy of this cRMP was validated by measuring certified reference materials (CRMs) and participating in the external quality assessment (EQA) scheme initiated by International Federation of Clinical Chemistry (IFCC) and National Center for Clinical Laboratory (NCCL). Biases were −0.64-1.51%, which were within the required equivalent limit. Excellent precision was obtained with intra- and inter-assay CVs of 0.42–0.73% and 0.20–0.43%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) was determined to be 0.24 and 1.19 μmol/L, respectively. A good liner response was obtained ranged from 30.0 to 895 μmol/L. Compared with the previous RMP for uric acid, the much easier one-step protein precipitation method without further evaporation, the simplified isocratic elution of chromatographic separation condition, and the shorter analysis running time in only 5 min allowed simpler and faster analysis. Moreover, this optimized cRMP was also applied for value assignment for clinical serum samples covered a wide concentration range of uric acid and obtained a decent calibration and measurement capability (CMC).

Salivary uric acid sensor using the fordable “Finger‐Powered” microfluidic device

AbstractHere, we report a novel biosensing system using a finger‐powered microfluidic device, which is suitable for daily self‐testing of uric acid in saliva. To realize the rapid determination of salivary uric acid, the biosensing system measures directly from the paper‐based saliva sampling device. The microfluidic device has the diaphragm pump, the reagent reservoir, and the reaction cell in which the electrochemical uric acid biosensor is embedded. Once the microfluidic chip has been folded, the finger‐powered microfluidic device prepares the reagent containing the saliva, which is ready to measure. A wireless potentiostat for electrochemical measurement of uric acid with the biosensor was also developed. Combining these elements together, the whole process from saliva sampling to determination was completed in less than a minute (Sensitivity: 0.03 nA/μM). The measurement results were also consistent with that measured using a commercially available uric acid determination kit. Hence, our method is expected to have the potential to enhance the use of biochemical information in the field of healthcare IoT.

The Effects of Use of Long-Term Second-Generation Antipsychotics on Liver and Kidney Function: A Prospective Study.

(1) Background: The second-generation antipsychotics (SGAPs) induce metabolic and inflammatory side effects, but documentation of their effects on the liver and kidneys is scarce. Aim: To study the three-year fluctuation of selected markers of renal and hepatic function in forensic psychiatric patients receiving SGAPs for more than five years. (2) Methods: Thirty-five forensic psychiatric patients (N = 35) were classified into two groups according to the type of SGAPs used for their treatment and the relevant risk of weight gain and metabolic complications. The three-year medication history, anthropometric data and biochemical data relevant to renal and hepatic function were retrieved from the individual medical files, specifically: serum levels of urea, uric acid, creatinine, alkaline phosphatase and amylase; the liver function enzymes, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and gamma-glutamyl transpeptidase(γ-GT), and also the inflammatory index C-reactive protein (CRP). (3) Results: The patients receiving the SGAPs with a low risk for weight gain showed no significant fluctuation in the biochemical markers over the three-year period. The patients receiving the SGAPs with a high risk for weight gain showed significant differences between at least two measurements of uric acid (p = 0.015), SGOT (p = 0.018) and SGPT (p = 0.051). They showed significantly higher levels of creatinine in the third year compared to the second year (p = 0.029), and SGOT in the second year compared to the first (p = 0.038), and lower levels of SGPT in the third year compared to the second (p = 0.024). (4) Conclusion:In addition to consideration of possible metabolic and inflammatory complications, the choice of an antipsychotic drug for long-term treatment should also take into account the risk of hepatotoxicity and kidney damage.

A STUDY OF SOME BIOCHEMICAL INDICATORS OF KIDNEY FUNCTION AND ESTIMATION OF SOME ELEMENTS CONCENTRATION IN THE BLOOD SERUM OF PATIENTS WITH CELIAC DISEASE

Celiac disease is a long-term autoimmune and digestive disorder that damages small intestine. The current study aimed to estimate some important enzymatic and biochemical variables for kidney functions in patients who eat gluten and abstain from it, compare them with healthy ones, see the usefulness of the GFD “Gluten free diet” to improve the health status of patients, and find biomarkers that contribute to the early diagnosis of celiac disease. The current study was conducted in Nineveh Governorate on patients who came to Al-Salam, Ibn Sina and Al-Khansa Hospital, as well as some private laboratories, as well as some patients from the students of Mosul University, the Technical Institute, and Al-Jada’a and Salamiyah camps after accurate diagnosis by specialist Doctors . 183 blood serum samples were collected for people of both sexes, aged between (2-25) years,. The samples were distributed into three groups, the group of patients who take gluten, including (62) samples (31 males and 31 females), and the group of patients who abstain from eating gluten, which includes (61) samples (31 males and 30 females), as well as the healthy group (control). It includes (60) samples (30 males and 30 females) The results of the current study showed a significant increase in tissue transglutaminase tTG-IgA enzyme for patients taking gluten compared to healthy subjects and no significant difference in enzyme activity in GFD patients compared to healthy subjects at a probability level (p ≤ 0.05). The results also showed that there was no significant difference in the measurement of creatinine, uric acid and glucose in patients who eat gluten as well as for gluten free diet GFD patients, and a significant increase in the measurement of urea in patients who take gluten compared with the healthy group , and no significant difference in the measurement of urea for GFD patients compared with control. The results also showed a significant decrease in Fe+2, Cu+2, Ca+2, and Zn+2 in patients who take gluten, as well as for GFD patients, compared with healthy subjects at a probability level (p ≤ 0.05). In conclusion monitoring of these biochemical markers is important in diagnosis and follow-up of celiac patients.

Level of Uric Acid in Women Suffering from Pre-Eclampsia and its Comparison with Normal Pregnancy

Objective: Current study is conducted to explore the variations in uric acid level in pre-eclamptic and normal healthy pregnancy in its third trimester in pregnant females. Methods: This descriptive cross sectional study was conducted to measure the serum uric acid level in mg/dl by kit method. The cutoff value was kept at 5mg/dl. The 10 ml of midstream urine was collected for estimation of urinary protein by dipstick method and graded from +1 to +3. For comparison between two groups in terms of levels of uric acid, independent sample t-test was used. Pearson Chi Square test was used to compare qualitative variables. Results: Raised levels of uric acid were obtained in 81.6% preeclampsia samples, and 13.1% found among normal samples, p&lt;0.01 showed that level of serum uric acid has a significant relationship with preeclampsia. Independent sample t-test showed a significant mean difference for SBP, DBP, and SUA between two groups, (p&lt;0.01) Conclusion: Significant high level of serum uric acid level was found in pre-eclamptic females than normotensive women. The findings suggest that measurement of serum uric acid may be a suitable marker in diagnosis of pre-eclampsia. Keywords: Pregnancy, Pre-eclampsia, Serum Uric Acid, Hypertension

Impact of hyperuricemia on coronary blood flow and in-hospital mortality in patients with acute myocardial infarction undergoing percutaneous coronary intervention

BackgroundAlthough serum uric acid (UA) is considered as a risk factor for cardiovascular disease, few data exist regarding the relationship between hyperuricemia, coronary blood flow, and subsequent outcome in patients with acute myocardial infarction (AMI). The purpose of our study is to assess whether hyperuricemia is associated with suboptimal coronary flow and increased risk of mortality in patients with AMI after percutaneous coronary intervention (PCI). MethodsUsing the Rural AMI registry data, 989 consecutive patients with AMI who underwent emergent PCI and had UA measurement at admission were analyzed. We defined hyperuricemia as serum UA ≥7.0 mg/dL in men and ≥ 6.0 mg/dL in women. The primary endpoint was suboptimal coronary flow, defined as post PCI Thrombosis In Myocardial Infarction flow grade ≤ 2. The secondary outcome was in-hospital mortality. ResultsHyperuricemia was found in 249 (25.2%) patients. Patients with hyperuricemia were more often complicated with cardiogenic shock compared with those without (16.9% vs. 7.4%, p < 0.001). In addition, the median high-sensitivity C-reactive protein was significantly higher in patients with hyperuricemia (0.18 mg/dL; IQR, 0.09–0.71 mg/dL) than in those without (0.14 mg/dL; IQR, 0.07–0.41 mg/dL, p < 0.05). Under these conditions, the prevalence of suboptimal coronary flow after PCI (17.3% vs. 10.1%, p < 0.05) and in-hospital mortality (10.8% vs. 3.6%, p < 0.001) were significantly higher in patients with hyperuricemia compared with those without. Multivariable logistic regression analysis revealed that hyperuricemia was significantly associated with suboptimal coronary flow [odds ratio (OR), 1.60; 95% confidence interval (CI), 1.02–2.49; p < 0.05] and in-hospital mortality (OR, 2.08; 95% CI, 1.05–4.12; p < 0.05). ConclusionsAssessment of serum UA upon admission provides useful information for predicting suboptimal coronary flow and in-hospital mortality in patients with AMI undergoing PCI.

Optoelectronic online monitoring system for hemodialysis and its data analysis

An optoelectronic system is presented for online measuring the concentrations of uric acid and β2-microglobulin in dialysates during hemodialysis (HD). The optoelectronic system consists of two sets of ultra-violet (UV) light emitting diodes (LEDs), flow cell, and photodiodes (PD); one set is for absorbance measurement of uric acid at 278 nm, while the other set is for β2-microglobulin measurement at 315 nm. The flow cell is employed for dialysate passing through during HD and for the online absorbance measurement. Further, a cylindrical flow cell is applied to reduce the total internal reflection (TIR) and to abate the stray light radiation on the PD for better linearity and less deviation. The system is first calibrated with standardized solutions and integrated with a commercial HD machine to test and monitor dialysate from 10 HD sessions of six (6) patients in the clinical study. The concentrations of uric acid and β2-microglobulin in dialysate can be obtained using our optoelectronic systems; more they are used to predict the concentrations in the patients’ serum using supporting vector machine (SVM) regression. The results displayed very good correlations, R2 = 0.8482 for uric acid and 0.7208 for β2-microglobulin, showing the great potentials of our systems with online HD monitoring capability.

Elevated Uric Acid Mediates the Effect of Obesity on Hypertension Development: A Causal Mediation Analysis in a Prospective Longitudinal Study.

ObjectiveAlthough elevated uric acid is associated with obesity and considered a predictor of hypertension, the causal linkage between the three metabolic conditions is not very clear. We aim to examine whether elevated uric acid mediates the effects of obesity on hypertension development.MethodsA total of 1984 participants (mean aged 53 years, 62.10% female) with repeated measurements of obesity, blood pressure, and uric acid 4 years apart in the Gusu cohort were included. We first applied cross-lagged panel analysis and bidirectional association analysis to delineate the temporal association between obesity and hyperuricemia. Then, a causal mediation model was constructed to further examine the causal role of hyperuricemia in the linkage between obesity and hypertension. Age, sex, education, cigarette smoking, alcohol consumption, fasting blood glucose, and lipids were adjusted.ResultsThe cross-lagged panel analysis demonstrated that the relationship from baseline obesity to follow-up hyperuricemia was stronger than that from baseline hyperuricemia to follow-up obesity (β: 0.09 vs 0.06, P<0.01 for BMI, β: 0.13 vs 0.07, P<0.01 for WC). Bidirectional association analysis found that baseline obesity predicted the risk of incident hyperuricemia (OR = 1.09, P<0.01 for BMI, OR = 1.05, P<0.01 for WC), but the other directional association was not statistically significant (all P>0.05). The causal mediation analysis found that hyperuricemia partially mediated the association of baseline BMI (mediate proportion: 3.09%, 95% CI: 0.97%~6.00% for SBP, 3.74%, 95% CI: 1.55%~7.00% for DBP) and baseline WC (mediate proportion: 5.56%, 95% CI: 2.01%~11.00% for SBP, 5.81%, 95% CI: 2.59%~10.00% for DBP) with follow-up blood pressures.ConclusionObesity preceded hyperuricemia and the latter partially mediated the relationship between obesity and hypertension, independent of behavioral and other metabolic factors.

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.

Prevalence and potential relevance of hyperuricemia in pediatric kidney transplant recipients-a CERTAIN registry analysis.

Asymptomatic hyperuricemia is frequently observed in pediatric kidney transplant recipients; symptomatic hyperuricemia, however, is a rare complication. Only few data are available in this patient population. We, therefore, investigated the prevalence of hyperuricemia and its association with kidney transplant function and blood pressure in a multicenter cohort of pediatric kidney transplant recipients. This is a retrospective, observational multicenter registry study. All pediatric kidney transplant recipients in the CERTAIN database with at least one documented serum uric acid level and a follow-up of 5years posttransplant were eligible. We identified 151 patients with 395 measurements of serum uric acid. We calculated the prevalence of hyperuricemia, analyzed potential risk factors and clinical consequences such as elevated blood pressure and reduced estimated glomerular filtration rate (eGFR). Statistical analysis was performed using IBM SPSS Statistics 26. One hundred and ten of 395 (27.8%) serum uric acid levels were above 416µmol/L (7.0mg/dL), defined as the upper limit of normal. Univariate analysis showed a significant (p=.026) inverse association of serum uric acid with eGFR overtime. There was no significant association of serum uric acid concentrations with body mass index (z-score), blood pressure (z-score), or sex. No episodes of gout were documented. This study shows that hyperuricemia is present in a considerable number of patients sometime after pediatric kidney transplantation and is associated with lower eGFR. Whether hyperuricemia contributes to faster decline of graft function or to the overall cardiovascular risk of these patients remains to be elucidated.