Hyperuricemia, Cardiovascular Disease, and Hypertension

Serum creatinine is more strongly associated with hyperuricemia than eGFR in males but not in females

OBJECTIVES

Serum creatinine and estimated glomerular filtration ratio (eGFR) are factors associated with hyperuricemia, though which is more closely associated with hyperuricemia remains unclear.

SUBJECTS AND METHODS

This retrospective cross-sectional study examined the associations of serum creatinine and eGFR with hyperuricemia using health check-up findings. Enrolled were 6020 individuals (3509 males, 2511 females) who underwent health check-ups from 2017 to 2021. The subjects were divided based on serum uric acid level into the normuricemia (males 1.5-7.0 mg/dl, females 1.5-< 6.0 mg/dl) and hyperuricemia (males >7.0 mg/dl, female ≥ 6.0 mg/dl) groups. Matched-pair analysis was used to evaluate the association between hyperuricemia and variables related to serum uric acid.

RESULTS

Matched-pair analysis results showed a significant association of serum creatinine with hyperuricemia in male subjects but not in females. Furthermore, propensity score obtained by binominal logistic regression demonstrated that serum creatinine had a greater association with hyperuricemia than eGFR in the males but not in females.

CONCLUSIONS

The present findings indicate an association of serum creatinine with hyperuricemia in males not only because of reduced renal function but other factors related to greater muscle mass, such as increased intake of protein-rich foods containing purines and increased uric acid production induced by accelerated creatinine metabolism.

Hyperuricemia - consequences of not initiating therapy. Benefits and drawbacks of treatment

Hyperuricemia, characterized by elevated levels of uric acid in the body, is associated with several health risks, including gout, urolithiasis and cardiovascular disease. Although treatment options are available, they can lead to hypersensitivity reactions, particularly with allopurinol therapy. This paper provides a comprehensive review of the consequences of hyperuricemia, the need for treatment and the potential adverse effects of allopurinol, illustrated by a case study. The study highlights the importance of careful consideration before initiating therapy, particularly in patients with comorbidities and concomitant medication. It emphasizes the need for vigilant monitoring and individualized treatment approaches to reduce adverse effects. In addition, genetic factors, particularly HLA-B*5801, play an important role in determining susceptibility to allopurinol hypersensitivity reactions. This paper highlights the importance of informed decision making in the management of hyperuricemia to optimize patient outcomes while minimizing the risks associated with treatment.

Emerging Roles of Xanthine Oxidoreductase in Chronic Kidney Disease

Xanthine Oxidoreductase (XOR) is a ubiquitous, essential enzyme responsible for the terminal steps of purine catabolism, ultimately producing uric acid that is eliminated by the kidneys. XOR is also a physiological source of superoxide ion, hydrogen peroxide, and nitric oxide, which can function as second messengers in the activation of various physiological pathways, as well as contribute to the development and the progression of chronic conditions including kidney diseases, which are increasing in prevalence worldwide. XOR activity can promote oxidative distress, endothelial dysfunction, and inflammation through the biological effects of reactive oxygen species; nitric oxide and uric acid are the major products of XOR activity. However, the complex relationship of these reactions in disease settings has long been debated, and the environmental influences and genetics remain largely unknown. In this review, we give an overview of the biochemistry, biology, environmental, and current clinical impact of XOR in the kidney. Finally, we highlight recent genetic studies linking XOR and risk for kidney disease, igniting enthusiasm for future biomarker development and novel therapeutic approaches targeting XOR.

Dual effects of serum urate on stroke risk and prognosis: insights from Mendelian randomization

Background

To investigate the causal associations of serum urate (SUA) with stroke risk and prognosis using Mendelian randomization (MR) and the potential mediating role of stroke risk factors in the causal pathways.

Methods

We used the random-effects inverse variance weighting (IVW) as our primary method. We initially performed two-sample univariable MR (UVMR) to identify the causal associations of SUA (n = 437,354) with any stroke (AS, FinnGen: n = 311,635; MEGASTROKE: n = 446,696), ischemic stroke (IS, FinnGen: n = 212,774; MEGASTROKE: n = 440,328), intracranial hemorrhage (ICH, FinnGen: n = 343,663; ISGC: n = 3,026), functional outcome after ischemic stroke at 90d (n = 4,363), and motor recovery within 24 months after stroke (n = 488), and then multivariable MR (MVMR) to estimate the direct causal effects of SUA on these outcomes, adjusting for potential confounders. Finally, we further conducted a two-step MR to investigate the potential mediating role of body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), and estimated glomerular filtration rate (eGFR) in the identified causal pathways.

Results

Genetically predicted elevated SUA levels were significantly associated with increased risk of AS (meta-analysis: OR = 1.09, 95% CI [1.04-1.13], p = 3.69e-05) and IS (meta-analysis: OR = 1.10, 95% CI [1.01-1.19], p = 0.021) and with improved poor functional outcome after ischemic stroke at 90d (OR = 0.81, 95% CI [0.72-0.90], p = 1.79e-04) and motor recovery within 24 months after stroke (OR = 1.42, 95% CI [1.23-1.64], p = 2.15e-06). In MVMR, SBP and DBP significantly attenuated the causal effects of SUA on AS, IS, and functional outcome after ischemic stroke at 90d and motor recovery within 24 months after stroke. Further mediation analyses showed that SBP mediated 52.4 and 34.5% of the effects of SUA on AS and IS, while DBP mediated 28.5 and 23.4% of the causal effects, respectively.

Conclusion

This study supports the dual role of genetically predicted SUA in increasing stroke risk, especially ischemic stroke risk, and in improving functional outcome and motor recovery. SBP and DBP are key mediators lying on the causal pathways of SUA with AS and IS.

Dyslipidemia and hyperuricemia: a cross-sectional study of residents in Wuhu, China

BACKGROUND

While dyslipidemia has been recognized as a potential risk factor for hyperuricemia, there is currently a dearth of large-scale data specifically focused on studying the relationship between these two conditions. To address this gap, the present study analyzed a dataset of 298,891 physical examination records to investigate in greater detail the clinical classification and compositional relationship between hyperuricemia and dyslipidemia.

METHODS

For this investigation, a cross-sectional research design was utilized to analyze physical examination data that was gathered from Yijishan Hospital in Wuhu, China between 2011 and 2016. Logistic regression was employed to examine the association between hyperuricemia and dyslipidemia. Furthermore, the association between hyperuricemia and dyslipidemia was evaluated based on the clinical classifications of dyslipidemia and its components.

RESULTS

A total of 298,891 participants from China (124,886 [41.8%] females) were included in the study, with an age range of 18 to 90 years (mean [SD]: 47.76 [13.54] years). In multivariate analysis, the odds of hyperuricemia was 1.878 times higher in patients with dyslipidemia compared to those without dyslipidemia (95% confidence interval [CI]: 1.835-1.922). In the clinical classification of dyslipidemia, individuals with hypertriglyceridemia and mixed hyperlipidemia had 1.753 times (95% CI: 1.706-1.802) and 1.925 times (95% CI: 1.870-1.982) higher odds of hyperuricemia, respectively, compared to those without dyslipidemia. Among the components of dyslipidemia, the odds ratios for hyperuricemia in individuals in the fourth quartile compared to those in the first quartile were 3.744 (95% CI: 3.636-3.918) for triglycerides, 1.518 (95% CI: 1.471-1.565) for total cholesterol, and 1.775 (95% CI: 1.718 - 1.833) for non-high-density lipoprotein cholesterol.

CONCLUSIONS

Dyslipidemia has been independently linked with hyperuricemia. Moreover, the elevation of triglycerides or total cholesterol levels, including conditions such as hypertriglyceridemia and mixed hyperlipidemia, have been observed to have a positive association with the development of hyperuricemia.

SERUM URIC ACID TO HDL CHOLESTEROL RATIO IS ASSOCIATED WITH DIABETIC CONTROL IN NEW ONSET TYPE 2 DIABETIC POPULATION

Since uric acid to HDL cholesterol ratio (UHR) is proposed as a novel predictor of metabolic and inflammatory disorders, we aimed to study UHR levels in patients with new onset type 2 diabetes mellitus (T2DM) and compare them to those in healthy controls. Patients with new onset T2DM were enrolled and control subjects were volunteers to participate without any established diseases. Laboratory data including UHR, fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) were compared. The mean UHR of the T2DM and control groups was 16±8% and 10±3%, respectively (p<0.001). Moreover, UHR was significantly and positively correlated with HbA1c (r=0.75, p<0.001), FBG (r=0.64, p<0.001), waist circumference (r=0.35, p<0.001), body mass index (r=0.20, p=0.002) and inversely correlated with glomerular filtration rate (r=-0.24, p<0.001). High levels of UHR might be associated with increased mean blood glucose levels for a long time, since UHR was correlated with both FBG and HbA1c in patients with new onset T2DM.

Update in uric acid, hypertension, and cardiovascular diseases

A direct relationship between serum uric acid levels and hypertension, cardiovascular, renal and metabolic diseases has been reported in many basic and epidemiological studies. Among these, high blood pression is one of the most common features associated with hyperuricemia. In this regard, several small-scale interventional studies have demonstrated a significant reduction in blood pressure in hypertensive or prehypertensive patients on uric acid-lowering drugs. These observation or intervention studies have led to affirm that there is a causal relationship between uric acid and hypertension. While the clinical association between uric acid and high blood pressure is notable, no clear conclusion has yet been reached as to whether lowering uric acid is beneficial to prevent cardiovascular and renal metabolic diseases. Recently, several prospective randomized controlled intervention trials using allopurinol and other uric acid-lowering drugs have been reported, and the results from these trials were almost negative, suggesting that the correlation between hyperuricemia and cardiovascular disease has no causality. However, it is important to note that in some of these recent studies there were high dropout rates and an important fraction of participants were not hyperuricemic. Therefore, we should carry caution in interpreting the results of these studies. This review article presents the results of recent clinical trials using uric acid-lowering drugs, focusing on hypertension and cardiovascular and renal metabolic diseases, and discusses the future of uric acid therapy.

A novel non-enzymatic electrochemical uric acid sensing method based on nanohydroxyapatite from eggshell biowaste immobilized on a zinc oxide nanoparticle modified activated carbon electrode (Hap-Esb/ZnONPs/ACE)

Hydroxyapatite-derived eggshell biowaste (Hap-Esb) has been fabricated and developed for the electrochemical detection of uric acid (UA). The physicochemical characteristics of the Hap-Esb and modified electrodes were evaluated using a scanning electron microscope and X-ray Diffraction analysis. Utilized as UA sensors, the electrochemical behavior of modified electrodes (Hap-Esb/ZnONPs/ACE) was assessed using cyclic voltammetry (CV). The superior peak current response observed for the oxidation of UA at Hap-Esb/ZnONPs/ACE, which was 13 times higher than that of the Hap-Esb/activated carbon electrode (Hap-Esb/ACE) is attributed to the simple immobilization of Hap-Esb on zinc oxide nanoparticle-modified ACE. The UA sensor exhibited a linear range at 0.01 to 1 μM, low detection limit (0.0086 μM), and excellent stability, which surpass the existing Hap-based electrodes reported in the literature. The facile UA sensor subsequently realized is also advantaged by its simplicity, repeatability, reproducibility, and low cost, applicable for real sample analysis (human urine sample).

Hyperuricemia predicts increased cardiovascular events in patients with chronic coronary syndrome after percutaneous coronary intervention: A nationwide cohort study from Japan

Background

The causal relationship between hyperuricemia and cardiovascular diseases is still unknown. We hypothesized that hyperuricemic patients after percutaneous coronary intervention (PCI) had a higher risk of major adverse cardiovascular events (MACE).

Methods

This was a large-scale multicenter cohort study. We enrolled patients with chronic coronary syndrome (CCS) after PCI between April 2013 and March 2019 using the database from the Clinical Deep Data Accumulation System (CLIDAS), and compared the incidence of MACE, defined as a composite of cardiovascular death, myocardial infarction, and hospitalization for heart failure, between hyperuricemia and non-hyperuricemia groups.

Results

In total, 9,936 patients underwent PCI during the study period. Of these, 5,138 patients with CCS after PCI were divided into two group (1,724 and 3,414 in the hyperuricemia and non-hyperuricemia groups, respectively). The hyperuricemia group had a higher prevalence of hypertension, atrial fibrillation, history of previous hospitalization for heart failure, and baseline creatinine, and a lower prevalence of diabetes than the non-hyperuricemia group, but the proportion of men and age were similar between the two groups. The incidence of MACE in the hyperuricemia group was significantly higher than that in the non-hyperuricemia group (13.1 vs. 6.4%, log-rank P < 0.001). Multivariable Cox regression analyses revealed that hyperuricemia was significantly associated with increased MACE [hazard ratio (HR), 1.52; 95% confidential interval (CI), 1.23-1.86] after multiple adjustments for age, sex, body mass index, estimated glomerular filtration rate, left main disease or three-vessel disease, hypertension, diabetes mellitus, dyslipidemia, history of myocardial infarction, and history of hospitalization for heart failure. Moreover, hyperuricemia was independently associated with increased hospitalization for heart failure (HR, 2.19; 95% CI, 1.69-2.83), but not cardiovascular death or myocardial infarction after multiple adjustments. Sensitive analyses by sex and diuretic use, B-type natriuretic peptide level, and left ventricular ejection fraction showed similar results.

Conclusion

CLIDAS revealed that hyperuricemia was associated with increased MACE in patients with CCS after PCI. Further clinical trials are needed whether treating hyperuricemia could reduce cardiovascular events or not.

The effect of serum uric acid concentration on the severity of chronic congestive heart failure

This study aimed to investigate the adverse effects of serum uric acid concentration on the severity of chronic congestive heart failure. One hundred patients with chronic congestive heart failure (several risk factors include hypertension, smoking, and diabetes mellitus) were enrolled in this study (51 females and 49 males). Participants were admitted to Alsader Medical City in Al-Najaf from August 2018 to March 2019. Detailed medical history and complete clinical examination were performed for all patients. The patients' ages ranged from 13-90 years, with a mean of 62.1±15.8 years, and the median was 65 years. No statistically significant age difference was observed between males and females (P-value=0.687). Increased serum uric acid had a directly negative effect on the severity of chronic congestive heart failure and hypertension. High serum uric acid concentration was associated with increased severity of chronic congestive heart failure class NYHA III and NYHA IV and a decrement in ejection fraction of the left ventricle.

Insights into the Inhibitory Mechanism of Viniferifuran on Xanthine Oxidase by Multiple Spectroscopic Techniques and Molecular Docking

Viniferifuran was investigated for its potential to inhibit the activity of xanthine oxidase (XO), a key enzyme catalyzing xanthine to uric acid. An enzyme kinetics analysis showed that viniferifuran possessed a strong inhibition on XO in a typical anti-competitive manner with an IC₅₀ value of 12.32 μM (IC₅₀ for the first-line clinical drug allopurinol: 29.72 μM). FT-IR and CD data analyses showed that viniferifuran could induce a conformational change of XO with a decrease in the α-helix and increases in the β-sheet, β-turn, and random coil structures. A molecular docking analysis revealed that viniferifuran bound to the amino acid residues located within the activity cavity of XO by a strong hydrophobic interaction (for Ser1214, Val1011, Phe914, Phe1009, Leu1014, and Phe649) and hydrogen bonding (for Asn768, Ser876, and Tyr735). These findings suggested that viniferifuran might be a promising XO inhibitor with a favorable mechanism of action.

Single and combined effect of bisphenol A with high sucrose diet on the diabetic and renal tubular dysfunction phenotypes in Drosophila melanogaster

In the present study, effect of exposure of bisphenol A (BPA) and combined exposure of BPA + HSD has been investigated on the glucose homeostasis and associated renal complications in Drosophila. Exposure of 1.0 mM BPA alone induced type 2 diabetes like condition (T2D) in adult male D. melanogaster via oxidative stress. Elevated TGF-β signaling was evident by increased expression of baboon (babo) in BPA exposed organism that stimulated the modulation of extracellular matrix (ECM) component collagen IV resulting in the fibrosis of the Malpighian tubules (MTs). Combined exposure of BPA + HSD (high sucrose diet) resulted in the increased magnitude of T2D and MTs dysfunction parameters. Taken together, the study illustrates that BPA has diabetogenic potential in exposed Drosophila that caused adverse effects on their MTs and combined exposure with BPA and HSD could aggravate the renal tubular dysfunction. The study further suggests the use of Drosophila model to study the environmental chemicals induced diabetes mediated renal dysfunction.

Update on Hypertension Research in 2021

In 2021, 217 excellent manuscripts were published in Hypertension Research. Editorial teams greatly appreciate the authors' contribution to hypertension research progress. Here, our editorial members have summarized twelve topics from published work and discussed current topics in depth. We hope you enjoy our special feature, "Update on Hypertension Research in 2021".

Hyperuricemia, a Non-Independent Component of Metabolic Syndrome, Only Predicts Renal Outcome in Chronic Kidney Disease Patients without Metabolic Syndrome or Diabetes

Uric acid (UA) is elevated in metabolic syndrome (MS) and diabetes (DM). UA is associated with central obesity and blood glucose and is proposed as a criterion of MS. Previous reports showed that UA could predict renal outcome in CKD. However, recent clinical trials did not demonstrate the benefits of urate-lowering agents (ULA) for renal outcome. Whether the prognostic value of UA for renal outcome is independent of MS or secondary to MS in CKD patients is unknown. Our study included 2500 CKD stage 1−4 Asian patients divided by UA tertiles and MS/DM. In linear regression, UA was associated with obesity, C-reactive protein, and renal function. In Cox regression, high UA was associated with worse renal outcome in non-MS/DM, but not in MS/DM: hazard ratio (95% confidence interval) of UA tertile 3 was 3.86 (1.87−7.97) in non-MS/DM and 1.00 (0.77−1.30) in MS/DM (p for interaction < 0.05). MS was associated with worse renal outcome, but redefined MS (including hyperuricemia as the 6th criteria) was not. In conclusion, hyperuricemia is associated with worse renal outcome in non-MS/DM and is not an independent component of MS in CKD stage 1−4 patients. Hyperuricemia secondary to MS could not predict renal outcome.

Naringenin Prevents Inflammation, Apoptosis, and DNA Damage in Potassium Oxonate-Induced Hyperuricemia in Rat Liver Tissue: Roles of Cytochrome C, NF-κB, Caspase-3, and 8-Hydroxydeoxyguanosine

Background: Hyperuricemia (HU) is a metabolic disease characterized by high uric acid levels in the blood. HU is a risk factor for diabetes, cardiovascular complications, metabolic syndrome, and chronic kidney disease. Purpose: The present study was performed to determine the effect of experimental HU on xanthine oxidase (XO), tumor necrosis factor-alpha (TNF-α), nuclear factor-kappa B (NF-κB), interleukin-17 (IL-17), cytochrome C, glutathione peroxidase (GPx), caspase-3, and 8-hydroxydeoxyguanosine (8-OHdG) levels in liver tissues of rats. Study Design: Thirty-five, male, Wistar albino-type rats were used for this study. Experimental groups were formed as follows: Group 1: control group; Group 2: potassium oxonate (PO) group; group 3: PO+NAR (naringenin; 2 weeks) group; and Group 4: PO (2 weeks)+NAR (2 weeks) group (total of 4 weeks). Methods: The first group was not given anything other than normal rat food and drinking water. In the second group, a 250 mg/kg intraperitoneal dose of PO was administered for 2 weeks. In the third group, 250 mg/kg intraperitoneal PO (application for 2 weeks) and 100 mg/kg NAR intraperitoneally 1 hr after each application were administered. In the fourth group, intraperitoneal PO administration was applied for 2 weeks, followed by intraperitoneal administration of NAR for 2 weeks (4 weeks in total). At the end of the experimental period, XO, TNF-α, NF-κB, IL-17, cytochrome C, GPx, caspase-3, and 8-OHdG levels were determined in liver tissues. Results: HU increased XO, TNF-α, NF-κB, IL-17, cytochrome C, caspase-3, and 8-OHdG levels in liver tissues. However, both 2 and 4 weeks of NAR supplementation decreased these values, and also NAR supplementation led to an increase in GPx levels in tissues. Conclusions: The results of the study show that increased inflammation, apoptosis, and DNA damage in experimental HU can be prevented by administration of NAR due to inhibition of cytochrome C, NF-κB, caspase-3, and 8-OHdG.

Sodium glucose co-transport 2 inhibitors for gout treatment

Hyperuricemia remains the most prevalent cause of gout. Gout patients present with joint inflammation and uric acid crystals deposition manifesting as tophi. The association of gout with increased risk of insulin resistance, diabetes, metabolic disorders, increased cardiometabolic risk, and kidney disease is well established. These factors influence the treatment plan, and current treatment options have limited cardiovascular risk reduction. So the need for novel treatments with a broad range of coverage for the complications is warranted. Sodium-glucose co-transporter 2 inhibitors are novel drugs approved for treating type-2 diabetes. They prevent glucose reabsorption and lower serum uric acid levels. Recently few studies have studied their association with reducing the risk of gout. They may help address the gout related complications through their recorded benefit with weight loss, improved insulin resistance, and cardiovascular benefits in recent studies. . SGLT2-Is may be useful to reduce the risk of gout in individuals with type 2 diabetes. Limited literature is available on the safety and efficacy of these novel antidiabetic drugs in patients with gout. This review is aimed to summarize the current knowledge on the role and effectiveness of novel antidiabetic medication as an early therapeutic option in gout patients.

Elevated serum uric acid is a facilitating mechanism for insulin resistance mediated accumulation of visceral adipose tissue

OBJECTIVE

Serum uric acid (SUA) has been associated with cardiometabolic conditions such as insulin resistance (IR) and visceral adipose tissue (VAT) accumulation. Here, we aimed to clarify a unifying mechanism linking elevated SUA to IR and VAT.

METHODS

We conducted analyses in 226 subjects from the UIEM cohort with both euglycemic hyperinsulinemic clamp (EHC) and dual X-ray absorptiometry (DXA) measurements for IR and VAT accumulation and explored the role of SUA and adiponectin by developing a network of causal mediation analyses to assess their impact on IR and VAT. These models were then translated to two population-based cohorts comprising 6337 subjects from NHANES 2003-2004 and 2011-2012 cycles in the US and ENSANUT Medio Camino 2016 in Mexico, using HOMA2IR and adipoIR as indicators of peripheral and adipose tissue IR, and METS-VF as a surrogate for VAT accumulation.

RESULTS

SUA has a mediating role inside a bidirectional relationship between IR and visceral obesity, which was similar using either gold standard measurements or surrogate measures for IR and VAT. Furthermore, adiponectin acts as a linking mediator between elevated SUA and both peripheral IR and VAT accumulation. The proportion of the mechanism for IR-mediated (in either peripheral or adipose tissue) VAT accumulation was greater, compared to VAT-mediated IR accumulation (10.53% [9.23%-12.00%] to 5.44% [3.78%-7.00%]). Normal-range SUA levels can be used to rule-out underlying cardio-metabolic abnormalities in both men and women.

CONCLUSIONS

Elevated SUA acts as a mediator inside the bidirectional relationship between IR and VAT accumulation and these observations could be applicable at a phenotype scale.

Tolerable upper intake level for dietary sugars

Following a request from five European Nordic countries, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was tasked to provide scientific advice on a tolerable upper intake level (UL) or a safe level of intake for dietary (total/added/free) sugars based on available data on chronic metabolic diseases, pregnancy-related endpoints and dental caries. Specific sugar types (fructose) and sources of sugars were also addressed. The intake of dietary sugars is a well-established hazard in relation to dental caries in humans. Based on a systematic review of the literature, prospective cohort studies do not support a positive relationship between the intake of dietary sugars, in isocaloric exchange with other macronutrients, and any of the chronic metabolic diseases or pregnancy-related endpoints assessed. Based on randomised control trials on surrogate disease endpoints, there is evidence for a positive and causal relationship between the intake of added/free sugars and risk of some chronic metabolic diseases: The level of certainty is moderate for obesity and dyslipidaemia (> 50-75% probability), low for non-alcoholic fatty liver disease and type 2 diabetes (> 15-50% probability) and very low for hypertension (0-15% probability). Health effects of added vs. free sugars could not be compared. A level of sugars intake at which the risk of dental caries/chronic metabolic diseases is not increased could not be identified over the range of observed intakes, and thus, a UL or a safe level of intake could not be set. Based on available data and related uncertainties, the intake of added and free sugars should be as low as possible in the context of a nutritionally adequate diet. Decreasing the intake of added and free sugars would decrease the intake of total sugars to a similar extent. This opinion can assist EU Member States in setting national goals/recommendations.

A New Predictor of Mortality in ST-Elevation Myocardial Infarction: The Uric Acid Albumin Ratio

Several studies have shown that high uric acid (UA) and low serum albumin (SA) values increase the risk of cardiovascular disease and mortality in ST-elevation myocardial infarction (STEMI). We determined whether the uric acid/albumin ratio (UAR) is a predictor of mortality in STEMI patients. All patients who presented at our center with a diagnosis of STEMI and underwent percutaneous intervention from 2015 to 2020 were screened consecutively; 4599 patients were included. A Cox proportional hazards model was used to evaluate UAR, and adjusted predictors obtained from laboratory findings and clinical characteristics contributed to mortality. Also, a regression model was presented with a directed acyclic graph (DAG). The median age of the patients was 58 years (IQR [interquartile range]: 50–67); 3581 patients (77.9%) were male. The incidence of mortality in the entire patient group was 11.9%. Median follow-up duration of all groups was 42 months. Multivariate Cox proportional regression (model-1) analysis showed age (increase 50 to 67 years; HR [hazard ratio]: 1.34, 95% CI 1.18–1.52) and UAR (increase 1.15–1.73; HR: 1.33, 95% CI 1.16–1.52) were associated with mortality. UAR may be a prognostic factor for mortality in STEMI patients and an easily accessible parameter to identify high-risk patients.

Xanthine oxidoreductase: A leading actor in cardiovascular disease drama

Cardiovascular diseases (CVD) are the leading cause of global mortality and their pathogenesis lies mainly in the atherosclerotic process. There are close connections linking oxidative stress and inflammation to endothelial dysfunction, atherosclerosis and, consequently, to CVD. This review focuses on the role of xanthine oxidoreductase (XOR) and its products on the development of chronic inflammation and oxidative stress, responsible for atheromatous plaque formation. Evidence is reported that an excessive level of XOR products favors inflammatory response and plaque development, thereby promoting major cardiovascular risk factors. Also, the relationship between hyperuricemia and hypertension as well as between XOR activity and CVD is confirmed. In spite of the increasing number of clinical studies investigating the output of cardiovascular patients treated with urate-lowering therapies (including uricosuric drugs, XOR inhibitors and recombinant uricase) the results are still uncertain. The inhibition of XOR activity appears more promising than just the control of uricemia level in preventing cardiovascular events, possibly because it also reduces the intracellular accumulation of urate, as well as the production of reactive oxygen species. However, XOR inhibition also reduces the availability of the multifaced mediator nitric oxide and, at present, can be recommended only in hyperuricemic patients.

Role of asymptomatic hyperuricemia in the progression of chronic kidney disease and cardiovascular disease

Previous research has investigated whether hyperuricemia serves as an independent risk factor for cardiovascular and renal diseases. Hyperuricemia is defined as an abnormally high level of uric acid (UA; i.e., serum urate level > 6.8 mg/dL). Hyperuricemia has been considered a complication of chronic kidney disease (CKD). However, it seems to play a pathogenic role in the progression of renal diseases. There has been increasing focus on the link between hyperuricemia and CKD. The results of randomized controlled trials have implied independent associations between hyperuricemia and the progression of cardiovascular and renal morbidities. These associations may be mediated by renin-angiotensin system activation, nitric oxide synthase inhibition, and macrovascular/microvascular disease development. There remains controversy regarding the use of serum UA level as an indirect index of renal vascular disease. This literature review focuses on the role of asymptomatic hyperuricemia in the progression of CKD, as well as the association between hyperuricemia and cardiovascular disease. It also provides a general overview of the physiological metabolism of UA.

Serum Uric Acid Level as a Predictive Biomarker of Gestational Hypertension Severity; A Prospective Observational Case-Control Study

BACKGROUND

Pre-eclampsia poses a significant potential risk of hypertensive disorders during pregnancy, a leading cause of maternal deaths. Hyperuricemia is associated with adverse effects on endothelial function, normal cellular metabolism, and platelet aggregation and adhesion. This study was designed to compare serum urate levels in normotensive pregnant women to those with pregnancy-induced hypertension, and to evaluate its value as a potential predictive marker of hypertension severity during pregnancy.

METHODS

A prospective, observational, case-control study conducted on 100 pregnant women in their third trimester. Pregnant women were classified into two groups (n=50) according to arterial blood pressure measurements: group I had normal blood pressure, and group II had a blood pressure of ≥ 140/90, which was further subdivided according to hypertension severity into IIa (pregnancy- induced hypertension, IIb (mild pre-eclampsia), and IIc (severe pre-eclampsia). Blood samples were obtained on admission. Serum urate, high sensitive C-reactive protein, and interleukin-1β levels, and lipid profile were compared among the groups.

RESULTS

A significant increase in the mean values of serum urate, C-reactive protein, and interleukin- 1β levels was detected in gestational hypertensives. In addition, there was a positive correlation between serum urate levels and C-reactive protein and interleukin-1β, as well as between serum urate levels and hypertension severity.

CONCLUSION

Hyperuricemia and increased C-reactive protein and interleukin-1β serum levels correlate with the severity of pregnancy-induced hypertension, and these biomarkers may play a role in the pathogenesis of pre-eclampsia. Serum urate measurement is sensitive, reliable markers that correlate well with the severity of hypertension in pregnant females with pre-eclampsia.

Serum Uric Acid Is a Weak Independent Predictor of Overall Survival in Older Adults

Hyperuricemia accompanies many pathologies that contribute to overall death rate. The population-based multifaceted study of older adults in Poland made it possible to assess the effect of serum uric acid (SUA) on overall mortality. The PolSenior study performed between 2007–2011 included 3926 participants aged 65 years or above (mean age 79 ± 9 years) not treated with xanthin oxidase inhibitors (XOI) who were stratified by sex and SUA concentration into six subgroups increasing by 1 mg/dL. In 2019, survival data were retrieved from the population register. The crude risk of death was significantly higher in men and women with SUA ≥ 7 mg/dL. After adjustment to statistically significant factors, SUA remained a risk factor of death in men with SUA ≥ 8 mg/dL only, potentially due to the limited number of women with high SUA levels. Furthermore, age, heart failure, diabetes, and activities of daily living ≤ 4 pts were identified as factors increasing mortality risk regardless of sex. The risk of death increased also with smoking, past stroke, COPD/asthma, and hs-CRP > 3 mg/dL for men; and eGFR < 45 mL/min/1.73 m², mini nutritional assessment ≤ 7 pts, and loop diuretics use for women. Mild hyperuricemia is a significant health status marker and an independent risk factor for overall mortality in older Caucasians not receiving XOI. Increased mortality is mostly limited to subjects with SUA levels ≥ 8 mg/dL.

Evaluation of uric acid disorders and associated factors in essential hypertensive patients at Wolkite University specialized hospital, Southern Ethiopia

BACKGROUND

Essential hypertension is a condition characterized by a rise in blood pressure of undetermined cause, includes 90% of all hypertensive cases and is a highly important public health challenge with major modifiable cause of morbidity and mortality. Uric acids disorders in particular hyperuricemia are significant problems in essential hypertensive patients and can cause substantial morbidity and mortality. Determination of uric acid disorders may play a major role in the management and early aversion of complications in hypertensive patient. Therefore, this study aimed to determine uric acid disorders and associated factors among essential hypertensive adults in the outpatient department at Wolkite University specialized Hospital, Southern Ethiopia from November 1 to February 30, 2021.

METHODS AND MATERIALS

An institional based cross sectional study was conducted on 270 essential hypertensive adults on follow-up in outpatient department from November 1 to February 30, 2021. Structured questionnaires through face to face interviews and participants' medical records were used to collect information on determinants related with uric acid disorders. The blood specimen was collected and level of serum uric acid, blood sugar and lipid profile was measured using standard principles and procedures with an ABX Pentra 400 automated chemistry analyzer. Bivariate and multivariate logistic regression analyses were done to identify factors associated with hyperuricemia. The p-value was set at <0.05 with a 95% confidence interval of the adjusted odds ratio.

RESULTS

A total of 270 adult essential hypertensive patients were participated in the study, among those 196(27.4%) of study participants were hyperuricemic with 95%CI (21.9, 33.3). Being alcoholic [(AOR: 15.68, 95% CI: (5.93, 21.41)], taking antihypertensive medication [(AOR: 11.56, 95% CI: (3.94, 23.80)], BMI > = 30 [(AOR: 4.89, 95% CI: (1.46, 25.5)] and being centrally obese [(AOR: 6.87, 95% CI: (2.53, 18.63)] were factors significantly associated with hyperuricemia.

CONCLUSION

In this study, the high burden of hyperuricemia (27.4%) was observed in essential hypertensive patients with follow-up in outpatient department. Taking alcohol and antihypertensive medication, being overweight and centrally obese were identified factors of uric acid disorders. The finding of this study should be taken into consideration to implement preventive interventions on identified predictors in hypertensive patients. Taking fruit and vegetable, and promoting physical exercise and determinations of serum uric acid level in adult essential hypertensive patients was recommended to minimize the emergence of hyperuricemia.

Impact of Camellia japonica Bee Pollen Polyphenols on Hyperuricemia and Gut Microbiota in Potassium Oxonate-Induced Mice

Camellia japonica bee pollen is one of the major types of bee pollen in China and exhibits antioxidant and anti-inflammatory activities. The aims of our study were to evaluate the effects and the possible mechanism of Camellia japonica bee pollen polyphenols on the treatment of hyperuricemia induced by potassium oxonate (PO). The results showed that Camellia japonica bee pollen ethyl acetate extract (CPE-E) owned abundant phenolic compounds and strong antioxidant capabilities. Administration with CPE-E for two weeks greatly reduced serum uric acid and improved renal function. It inhibited liver xanthine oxidase (XOD) activity and regulated the expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), organic anion transporter 1 (OAT1), organic cation transporter 1 (OCT1) and ATP-binding cassette superfamily gmember 2 (ABCG2) in kidneys. Moreover, CPE-E suppressed the activation of the toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB (TLR4/MyD88/NF-κB) signaling pathway and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in PO-treated mice, and related inflammatory cytokines were reduced. CPE-E also modulated gut microbiota structure, showing that the abundance of Lactobacillus and Clostridiaceae increased in hyperuicemic mice. This study was conducted to explore the protective effect of CPE-E on hyperuricemia and provide new thoughts for the exploitation of Camellia japonica bee pollen.

Data-driven identification of complex disease phenotypes

Disease interaction in multimorbid patients is relevant to treatment and prognosis, yet poorly understood. In the present work, we combine approaches from network science, machine learning and computational phenotyping to assess interactions between two or more diseases in a transparent way across the full diagnostic spectrum. We demonstrate that health states of hospitalized patients can be better characterized by including higher-order features capturing interactions between more than two diseases. We identify a meaningful set of higher-order diagnosis features that account for synergistic disease interactions in a population-wide (N = 9 M) medical claims dataset. We construct a generalized disease network where (higher-order) diagnosis features are linked if they predict similar diagnoses across the whole diagnostic spectrum. The fact that specific diagnoses are generally represented multiple times in the network allows for the identification of putatively different disease phenotypes that may reflect different disease aetiologies. At the example of obesity, we demonstrate the purely data-driven detection of two complex phenotypes of obesity. As indicated by a matched comparison between patients having these phenotypes, we show that these phenotypes show specific characteristics of what has been controversially discussed in the medical literature as metabolically healthy and unhealthy obesity, respectively. The findings also suggest that metabolically healthy patients show some progression towards more unhealthy obesity over time, a finding that is consistent with longitudinal studies indicating a transient nature of metabolically healthy obesity. The disease network is available for exploration at https://disease.network/.

Hyperuricemia and Cardiovascular Risk

As the prevalence of hyperuricemia (elevated uric acid levels in the blood) increases, the relationship between serum uric acid levels and cardiovascular risk has garnered increased interest. Several studies have highlighted that elevated uric acid levels are likely tied to increased cardiovascular disease risk. Specifically, the presence of hyperuricemia is well-established to contribute to the onset of gout (an inflammatory condition characterized by painful/swollen joints). Several studies have shown that the risk of developing gout is strongly associated with the degree of hyperuricemia. In this review, we will provide insight into the association between gout and cardiovascular disease risk. It is also important to gain insight into the pathophysiology of gout to understand the contributions to cardiovascular disease risk as well as improve diagnosis and target treatment more effectively. An interdisciplinary approach for gout management and areas for further investigation will be discussed in this review.

Uric acid lowering improves insulin sensitivity and lowers blood pressure: a meta-analysis of randomized parallel-controlled clinical trials

Objectives

This meta-analysis aimed to investigate whether uric acid lowering treatment can improve β-cell function and insulin sensitivity.

Methods

PubMed, Cochrane Library, EMBASE and China Biology Medicine were searched up to March 1, 2020. Randomized controlled clinical trials of urate lowering therapy in hyperuricemia patients were included in meta-analysis. Effect size was estimated as mean difference with 95% confidence interval (CI).

Results

Our search yielded 7 eligible trials with 503 participants. This meta-analysis showed that uric acid-lowering therapy decreased fasting insulin -1.43 µIU/ml (weighted mean differences (WMD, 95% CI -2.78 to -0.09), homeostasis model assessment of insulin resistance -0.65 (WMD, 95% CI -1.05 to -0.24), systolic blood pressure -2.45 mm Hg (WMD, 95%CI -4.57 to -0.33) and diastolic blood pressure -3.41 mm Hg (WMD, 95%CI -3.87 to -2.95). However, the treatment had no significant effect on fasting plasma glucose (WMD -0.19 mmol/L, 95%CI -0.42 to 0.05), homeostasis model assessment of β-cell function index (WMD -0.02, 95%CI -0.28 to 0.24), total cholesterol (WMD 0.18 mg/dl; 95%CI, -1.39 to 1.75) and triglyceride (WMD 3.15 mg/dl, 95% CI -9.83 to 16.14).

Conclusion

Uric acid-lowering therapies might improve insulin sensitivity and lower blood pressure, but had no significant effect on HOMA-β and serum lipids.

Hepatic and Renal Impacts of Lesinurad on Experimental Hyperuricemia: Biochemical, Molecular and Pathological Investigations

&lt;b&gt;Background and Objective:&lt;/b&gt; Hyperuricemia is one of the most dangerous threats to human life. It is mainly associated with gout and inflammatory arthritis. Therefore, finding a safe medication that does not have severe side-effects is a goal shared by most physicians. The current study aimed to evaluate the effect of lesinurad (Zurampic; ZUR) and allopurinol (ALP), both alone or in combination, on the treatment of hyperuricemic mice at the biochemical, molecular and cellular levels. &lt;b&gt;Materials and Methods:&lt;/b&gt; Lesinurad and allopurinol were orally administered to hyperuricemic and control mice for seven consecutive days, either alone or in combination. Levels of uric acid and xanthine oxidase activity, blood urea nitrogen, creatinine, ALT and AST were measured in the serum. The mRNA expression of mouse hepatic guanine deaminase (Gda), purine nucleotide phosphorylase (PNP), renal urate anion transporter-1 (URAT-1) and OAT-1 transporters were examined. The renal tissues were examined using H and E staining and the immunoreactivity technique. &lt;b&gt;Results:&lt;/b&gt; Lesinurad and allopurinol administration resulted in a significant decrease in serum levels of uric acid, blood urea nitrogen and xanthine oxidase activity reported in hyperuricemic mice. Both partially reversed oxonate-induced alterations in renal mURAT-1 and mOAT-1 expressions, as well as alterations in the immunoreactivity of Bcl2. All showed an increase in renal uric acid secretion and excretion. ALP and ZUT significantly decreased the increase in Gda and PNP expression reported in hyperuricemic mice. The combined administration of ZUR and ALP restored and improved renal function histopathological changes reported in hyperuricemic mice. &lt;b&gt;Conclusion:&lt;/b&gt; The hypouricemic impact of both lesinurad and allopurinol in the treatment of hyperuricemia in mice was confirmed following hyperuricemia treatment.

Synthesis of Nylon 6/Modified Carbon Black Nanocomposites for Application in Uric Acid Adsorption

High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the absorption of toxins and hemocompatibility. MBC and nanocomposites showed excellent uric acid removal (78-82%) and hemocompatibility (1.6-1.8%). These results suggest that Nylon 6/MCB nanocomposites with low loading percentages can be used on a large scale without compatibility problems with blood.

Biomolecules and Electrochemical Tools in Chronic Non-Communicable Disease Surveillance: A Systematic Review

Over recent three decades, the electrochemical techniques have become widely used in biological identification and detection, because it presents optimum features for efficient and sensitive molecular detection of organic compounds, being able to trace quantities with a minimum of reagents and sample manipulation. Given these special features, electrochemical techniques are regularly exploited in disease diagnosis and monitoring. Specifically, amperometric electrochemical analysis has proven to be quite suitable for the detection of physiological biomarkers in monitoring health conditions, as well as toward the control of reactive oxygen species released in the course of oxidative burst during inflammatory events. Besides, electrochemical detection techniques involve a simple and swift assessment that provides a low detection-limit for most of the molecules enclosed biological fluids and related to non-transmittable morbidities.

Antioxidant Blueberry Anthocyanins Induce Vasodilation via PI3K/Akt Signaling Pathway in High-Glucose-Induced Human Umbilical Vein Endothelial Cells

Blueberries are rich in antioxidant anthocyanins. The hypotensive effects of blueberry anthocyanins in endothelial cells was investigated here. Pretreatment with blueberry anthocyanin extract, malvidin, malvidin-3-glucoside, and malvidin-3-galactoside significantly ameliorated high-glucose-induced damage by enhancing endogenous antioxidant superoxide dismutase (SOD) and heme oxygenase-1 (HO-1), lowering reactive oxygen species (ROS) generation and NADPH oxidase isoform 4 (NOX4) expression, and increasing the cell vitalities. They also effectively induced a vasodilatory effect by increasing the vasodilator nitric oxide (NO) and its promoters endothelial NO synthase (eNOS) and peroxisome proliferator-activated receptor-γ (PPARγ) levels as well as by decreasing the vasoconstrictor angiotensin-converting enzyme (ACE), xanthine oxidase-1 (XO-1), and low-density lipoprotein (LDL) levels. The activation of phosphoinositide 3-kinase (PI3K)/Akt signaling pathway and the breakdown of protein kinase C zeta (PKCζ) pathway were involved in the bioactivities. The results indicated blueberry anthocyanins protected endothelial function against high-glucose (HG) injury via antioxidant and vasodilatory mechanisms, which could be promising molecules as a hypotensive nutraceutical for diabetes patients.

The serum uric acid level in females may be a better indicator of metabolic syndrome and its components than in males in a Japanese population

BACKGROUND

Although the level of uric acid (UA) is higher in males, increased UA level in females was reported to be closely associated with prevalence of metabolic syndrome (Mets) leading to atherosclerotic cardiovascular disease (ASCVD). Few data exist regarding the gender diferences in relationship between the serum UA levels and cardo-metabolic risk in the Japanese population, which generally contains a lower proportion of obesity than Western populations.

METHODS

This cross-sectional study was designed to investigate, by gender, the association between the serum UA level and abdominal obesity, and thereby cardio-metabolic risk i.e. presence of Mets and its components using a sample of 8567 apparently healthy subjects females: n = 3334, males: n = 5233 at the Health Planning Center of Nihon University Hospital between September 2015 and August 2016.

RESULTS

Receiver operating characteristic analysis was performed to reveal the accuracy of serum UA level as a predictor of abdominal obesity based on the Japanese criteria of Mets (females vs. males: area under the curve, 0.751 vs 0.609). Furthermore, the serum UA level and proportion of abdominal obesity rose with increasing age in females; in males, however, these parameters did not change in parallel with age. Furthermore, the serum UA levels in females reflected a status of cardio-metabolic risk when compared with males in a multi-logistic regression analysis. It is particularly worth noting that in the above-mentioned multivariate logistic regression analysis, the odds ratio of hyperuricemia in females was generally 1.3-2.5 times higher than that in males.

CONCLUSIONS

Compared with males, increased serum UA level in females might be involved in abdominal obesity and cardio-metabolic risk, possibly leading to the development of ASCVD even in a Japanese population. This may be due to gender differences affecting the development of abdominal obesity and changes in the serum UA levels with age.

CLINICAL TRIAL REGISTRATION

UMIN (http://www.umin.ac.jp/) Study ID:　UMIN000035901retrospectively registered 1 March 2018.

Impact of Lesinurad and allopurinol on experimental Hyperuricemia in mice: biochemical, molecular and Immunohistochemical study

BACKGROUND

Hyperuricemia is an abnormal increase in uric acid levels in the blood. It is the cause of gout that manifested by inflammatory arthritis and painful disable. Therefore, current study evaluated the potential ameliorative impact of Lesinurad and Allopurinol on the kidneys of hyperuricemic mice at the biochemical, molecular and cellular levels.

METHODS

Lesinurad and allopurinol alone or in combination were orally administered to hyperuricemic and control mice for seven consecutive days. Levels of uric acid and blood urea nitrogen, along with antioxidants and inflammatory cytokines (IL-1β and TNF-α) were measured in the serum. The mRNA expression of mouse urate anion transporter-1, glucose transporter 9, organic anion transporters, in renal tissues were examined using quantitative real time PCR. Simultaneously, the immunoreactivity of transforming growth factor-beta 1 was examined immunohistochemically.

RESULTS

Lesinurad and allopurinol administration resulted in significant decrease in serum levels of uric acid, blood urea nitrogen, xanthine oxidase activity, catalase, glutathione peroxidase and inflammatory cytokines (IL-1β and TNF-α) reported in hyperuricemic mice. Both partially reversed oxonate-induced alterations in renal mURAT-1, mGLUT-9, mOAT-1 and mOAT-3 expressions, as well as alterations in the immunoreactivity of TGF- β1, resulting in the increase of renal uric acid secretion and excretion. The combined administration of lesinurad and ALP restored all altered parameters in a synergistic manner, improving renal function in the hyperuricemic mouse model employed.

CONCLUSION

This study confirmed synergistic ameliorative hypouricemic impact of both lesinurad and allopurinol in the treatment of hyperuricemia in mice at the biochemical, molecular and cellular levels.

Uric Acid and Arterial Stiffness

Hyperuricemia is usually associated with hypertension, diabetes mellitus, metabolic syndrome and chronic kidney disease. Accumulating data from epidemiological studies indicate an association of increased uric acid (UA) with cardiovascular diseases. Possible pathogenic mechanisms include enhancement of oxidative stress and systemic inflammation caused by hyperuricemia. Arterial stiffness may be one of the possible pathways between hyperuricemia and cardiovascular disease, but a clear relationship between increased UA and vascular alterations has not been confirmed. The review summarizes the epidemiological studies investigating the relationship between UA and arterial stiffness and highlights the results of interventional studies evaluating arterial stiffness parameters in patients treated with UA-lowering drugs.

Fasting blood glucose is predictive of hypertension in a general Japanese population

OBJECTIVE

This study was conducted to identify whether higher fasting blood glucose levels is predictive of hypertension by a large-scale longitudinal design.

METHODS

We conducted a retrospective 5-year cohort study using the data from 13 201 Japanese individuals who underwent annual medical examinations in 2004 and were reevaluated 5 years later. This study included individuals without diabetes or hypertension between ages 30 and 85 years in 2004. The cumulative incidences of hypertension over 5 years in each 10 mg/dl of fasting blood glucose levels were calculated. Moreover, we examined risk factors and calculated odds ratios (ORs) for developing hypertension after adjustments for age, sex, BMI, smoking and drinking habits, dyslipidemia, chronic kidney disease, serum uric acid, and fasting blood glucose levels by logistic regression analyses.

RESULTS

We analyzed 10 157 participants (age: 48.9 ± 10.7 years; 43.4% men) without diabetes or hypertension in 2004. After multiple adjustments, higher baseline blood glucose level is an independent risk for hypertension (OR: 1.176; 95% CI 1.086-1.275), as well as aging, women, higher BMI, drinking habits, and higher serum uric acid. After stratifying by sex, higher baseline blood glucose level is an independent risk for hypertension both in women (OR: 1.295; 95% CI 1.135-1.478) and men (OR: 1.108; 95% CI 1.001-1.227). When we conducted the same analysis using glycated hemoglobin instead of blood glucose, glycated hemoglobin was not a risk for hypertension.

CONCLUSION

Higher fasting blood glucose is an independent risk for developing hypertension. Further studies are needed to determine if treatment for elevated blood glucose can prevent developing hypertension.

Leptin Levels are Associated with Subclinical Cardiac Dysfunction in Obese Adolescents

PURPOSE

The purposes of this study were to use speckle tracking echocardiography to confirm the influence of obesity on cardiac functions and to assess their relationships with leptin and uric acid levels in obese adolescents.

METHODS

Eighty-one participants aged 16-19 years were recruited and classified as either non-obese (n = 30) or obese (n = 51). Global longitudinal strain (GLS), leptin and uric acid levels for each group were assessed and compared. The data from obese participants were then compared based on their leptin levels and analyzed for correlation using regression analysis.

RESULTS

The obese group had significantly lower absolute GLS compared to the non-obese group (19.10 ± 0.30 versus 21.10 ± 0.30%, p < 0.001). In obese group, subclinical cardiac dysfunction was worse in the hyperleptinemic group than that of the normoleptinemic group (p = 0.03). Multivariate regression analysis showed that leptin and triglyceride levels were negatively associated with absolute GLS. Leptin could predict the absolute GLS with β = -0.35 (p = 0.02).

CONCLUSION

Subclinical left ventricular systolic dysfunction was found in obese adolescents, while GLS was worse in the hyperleptinemic subjects. Leptin, but not uric acid, levels were associated with a worsening of GLS.

Protective Effects of α-Lipoic Acid on Vascular Oxidative Stress in Rats with Hyperuricemia

The aim of the present study was to observe the protective effects of α-lipoic acid (ALA) on vascular injury in rats with hyperuricemia (HUA). The ALA treatment groups (10, 30 and 90 mg/kg, respectively) were administered with ALA via gavage for 2 weeks. Subsequently, the levels of blood urea nitrogen (BUN), creatinine (CREA), uric acid (UA), total cholesterol (TC), high density lipoprotein-C (HDL-C) and low density lipoprotein-C (LDL-C) were measured; the activities of glutathione peroxidase (GSH-Px), catalase (CAT), malonaldehyde (MDA), superoxide dismutase (SOD) and xanthine oxidase (XOD) were also determined. The thoracic aorta of rats in each experimental group was observed under a light microscope; ultrastructural analysis was performed. SOD and CAT protein contents were investigated by Western blotting. The results revealed that: i) Compared with the model group, the levels of UA were decreased in the ALA groups and the levels of BUN, CREA, TC, and LDL-C decreased in the 30 and 90 mg/kg ALA groups (P<0.05); ii) compared with the model group, the activities of GSH-Px, SOD and XOD were increased and the levels of MDA were reduced in the 90 mg/kg ALA group (P&lt;0.05); and iii) in the model and 10 mg/kg ALA groups, edema and shedding were observed in endothelial cells. Compared with the model and 10 mg/kg ALA groups, the 30 and 90 mg/kg ALA groups exhibited fewer swollen endothelial cells. In summary, the results of the present study indicated that HUA resulted in vascular oxidative stress injury and decreased the activity of antioxidative enzymes, which leads to endothelial cell damage and vascular lesions. ALA may serve as a therapeutic agent for the treatment of HUA-induced endothelial dysfunction.

Expression of miR-217 and HIF-1α/VEGF pathway in patients with diabetic foot ulcer and its effect on angiogenesis of diabetic foot ulcer rats

OBJECTIVE

To investigate the expression of miR-217 and HIF-1α/VEGF pathway in patients with diabetic foot ulcer (DFU) and its effect on angiogenesis in DFU rats.

METHODS

The serum levels of miR-217, HIF-1α and VEGF were detected in DFU and simple diabetes mellitus (DM) patients, and healthy controls. DFU rat models were established and treated with miR-217 inhibitors and/or HIF-1α siRNA. The ulcer healing of DFU rats was observed. Besides, ELISA method was performed to detect the serum level of HIF-1α, VEGF and inflammatory factors, immunohistochemical (IHC) method to test the micro-vessel density (MVD), as well as qRT-PCR and Western blot to determine expressions of miR-217, HIF-1α, VEGF, VEGFR2, eNOS, MMP-2, and MMP-9 in tissues.

RESULTS

The serum levels of miR-217 were up-regulated while HIF-1α and VEGF were down-regulated in DFU patients and rats when compared with DM and healthy controls (all P < 0.05). Dual-luciferase reporter gene assay confirmed that HIF-1α was the direct target gene of miR-217. DFU rats treated with miR-217 inhibitors had decreased foot ulcer area and accelerated ulcer healing, with significantly reduced inflammatory factors (IL-1β, TNF-α and IL-6), as well as elevated HIF-1α and VEGF (all P < 0.05); meanwhile, they remarkably increased the MVD in foot dorsum wound tissues and the protein expressions of HIF-1α, VEGF, VEGFR2, eNOS, MMP-2, and MMP-9 (all P < 0.05).

CONCLUSION

Inhibiting miR-217 could up-regulate HIF-1α/VEGF pathway to promote angiogenesis and ameliorate inflammation of DFU rats, thereby effectively advancing the healing of ulcerated area.

Hyperuricemia Associated with Thiazide Diuretics in Hypertensive Adults

Introduction

Thiazide diuretics are essential first-line anti-hypertensive drugs which not only maintain blood pressure but also reduce stroke and congestive heart failure associated with morbidity and mortality in hypertensive patients. However, thiazide diuretics are associated with elevated serum uric acid (SUA) levels. This study aimed to evaluate the impact of thiazide diuretic use on their SUA levels among hypertensive individuals of Pakistan.

Methods

In this cross-sectional, prospective study, adult hypertensive patients were recruited. They were divided into two groups - thiazide diuretic group and non-thiazide group. Demographic characteristics, hypertension-related characteristics, and SUA levels were included. Data were then entered and analysed using SPSS for Windows version 22.0 (IBM Corp., Armonk, NY, USA).

Results

In the thiazide group, 24.5% were hyperuricemic as compared to 15.3% in the non-thiazide group (p=0.03). The overall mean SUA levels in the thiazide group were significantly higher than those in the non-thiazide group (5.9 ± 2.1 vs. 5.3 ± 2.7 mg/dL; p=0.02). Males in the thiazide group also showed a similar pattern (5.9 ± 2.3 vs. 5.1 ± 2.1 mg/dL; p=0.02); however, the differences were insignificant in females. Patients using thiazide diuretics for one to three years were more non-hyperuricemic than hyperuricemic (p=0.000). Among hyperuricemic patients, 36.5% were taking thiazides for three to four years and 46% were taking them for more than four years (p<0.05).

Conclusion

Hyperuricemia is a more common occurrence in thiazide diuretic users as compared to non-users. The overall sample, and men using thiazide diuretics, reported a higher mean SUA as compared to non-users. As the years of thiazide usage advanced, the number of hyperuricemic participants also significantly increased.

Benzo[a]pyrene alters vascular function in rat aortas ex vivo and in vivo

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon found in tobacco smoke and air pollution products. BaP exposure has been recently suggested to be a risk factor for hypertension in coke oven workers. The mechanisms of BaP on vascular smooth muscle function remain unclear. Here, we examined the influence and possible mechanism of BaP on vasoconstriction in rat thoracic aortas ex vivo and in vivo. In vivo exposure of rats to BaP (20 mg/kg) for 8 weeks caused a significant enhancement in the systolic blood pressure and enhanced aortic hyperreactivity to α1-adrenoceptor selective agonist phenylephrine in aortas. BaP (1 and 10 μM) treatment for 18 h induced an enhancement of phenylephrine-induced vasoconstriction in the organ cultures of aortas. Aryl hydrocarbon receptor antagonist α-naphthoflavone, protein kinase C (PKC) inhibitor chelerythrine, mitogen-activated protein kinases (MAPK) inhibitor PD98059, myosin light chain kinase (MLCK) inhibitor ML-9, and Rho-kinase inhibitor Y-27632 significantly suppressed BaP-enhanced vasoconstriction. BaP time-dependently triggered reactive oxygen species (ROS) production in primary vascular smooth muscle cells. Both antioxidant N-acetylcysteine and NAD(P)H oxidase inhibitor diphenyleneiodonium significantly inhibited BaP-triggered ROS production and vasoconstriction. These results suggest that BaP enhances aortic vasoconstriction via the activation of ROS and muscular signaling molecules PKC, MAPK, MLCK, and Rho-kinase.

Switching from allopurinol to febuxostat: efficacy and safety in the treatment of hyperuricemia in renal transplant recipients

The aim of this study was to evaluate the efficacy and tolerability of febuxostat in renal transplant recipients who were previously treated with allopurinol (the daily oral dose is 100 mg). A 6-month cohort study was conducted with 46 renal transplant recipients who had hyperuricemia. In 22 patients, treatment was changed from allopurinol to febuxostat (febuxostat was given at an oral dose of 20 mg once a day), and the other 24 patients continued the allopurinol treatment (the daily oral dose is 100 mg). The serum levels of uric acid (UA), creatinine, other biochemical parameters, estimated glomerular filtration rate (eGFR), and adverse events were measured at baseline as well as at 1, 3, and 6 months after the switch to febuxostat. Serum UA levels significantly decreased from 470.82 ± 34.37 to 378.77 ± 51.97 μmol/L in the febuxostat group, and decreased from 469.46 ± 33.47 to 428.21 ± 23.37 μmol/L in the allopurinol group. The eGFR increased from 75.55 to 85.23 mL/min in the febuxostat group, and decreased from 78.79 to 70.31 mL/min in the allopurinol group. In renal transplant recipients, febuxostat reduced the serum UA levels resulting in minor short-term improvement of renal function with no changes in the other biochemical parameters.