Asymptomatic hyperuricemia is a strong risk factor for resistant hypertension in elderly subjects from general population

Causal relationship between serum uric acid and cardiovascular disease: A Mendelian randomization study

Background

Observational studies have established an association between serum uric acid and cardiovascular disease (CVD). However, these studies are susceptible to uncontrolled confounders and reverse causality bias. To overcome these challenges, we employed a two-sample Mendelian randomization (MR) approach to investigate the causal link between serum uric acid and CVD.

Methods

We utilized Genome-wide association study (GWAS) data for serum uric acid and six CVD: coronary artery disease (CAD), hypertension, myocardial infarction (MI), heart failure (HF), angina, and coronary heart disease (CHD). MR analyses employed inverse variance weighting (IVW), MR-Egger, weighted median, and weighted model. Sensitivity analyses were conducted to assess result reliability, including Cochrane's Q test, MR-Egger intercept, MR-PRESSO, and the leave-one-out approach.

Results

IVW analysis revealed that a genetic predisposition to elevated serum uric acid levels significantly increases the risk of CVD, with higher odds ratios (ORs) observed for CAD (OR: 1.227; 95 % CI: 1.107-1.360, P = 0.0002), hypertension (OR: 1.318, 95 %CI: 1.184-1.466, P = 2.13E-06), MI (OR: 1.184, 95 %CI: 1.108-1.266, P = 2.13E-06), HF (OR: 1.158, 95 %CI: 1.066-1.258, P = 2.13E-06), angina (OR: 1.150, 95 %CI: 1.074-1.231, P = 0.0002) and CHD (OR: 1.170, 95 %CI: 1.072-1.276, P = 0.0005). Sensitivity analysis research results have robustness.

Conclusion

This MR study robustly demonstrates a significant causal relationship between genetically elevated serum uric acid and various cardiovascular diseases, suggesting that higher levels may enhance the risk of cardiovascular events. Consequently, patients with elevated uric acid levels warrant early and aggressive interventions to mitigate cardiovascular risks.

Clinicopathological characteristics and associated factors of idiopathic membranous nephropathy with hyperuricemia: a single-centered cross-sectional study

PURPOSE

This study was designed to investigate the clinicopathological features of idiopathic membranous nephropathy (IMN) with hyperuricemia (HUA), together with associated factors within 10 years in a single centre in Shandong Province.

METHODS

In this cross-sectional study, we analysed the clinical and pathological data of 694 IMN patients in our hospital from January 2010 to December 2019. Based on serum uric acid (UA) level, the patients were divided into hyperuricemia (HUA) group (n = 213) and normal serum uric acid (NUA) group (n = 481). Multi-variate logistic regression analysis was conducted on to screen the associated factors of HUA.

RESULTS

213 (30.69%) IMN patient were complicated with HUA. Compared with the patients with NUA, significant increase was noticed in the proportion of patients showing edema, concurrent hypertensive disease or diabetes mellitus (DM), as well as the proportion of positive glomerular capillary loop IgM and positive C1q in the HUA group (P < 0.05). In addition, significant increase was noticed in the 24 h urine protein, serum creatinine, triglycerides, complement C3 and complement C4 in HUA group compared with those of NUA group (all P < 0.05). With gender as a control factor, multi-variate logistic regression analysis showed positive glomerular capillary loops C1q, serum albumin, serum phosphorus were associated with IMN combined with HUA in male, while triglycerides and serum creatinine were associated with IMN combined with HUA in female counterparts.

CONCLUSION

About 30.69% of IMN patients had HUA, with a male predominance than female. In male patients with IMN, higher serum albumin level and serum phosphorus level were associated with higher incidence of HUA, while in female IMN patients, higher serum triglyceridemia and serum creatinine level were associated with higher incidence of HUA. Therefore, it can be targeted to prevent the occurrence of HUA in IMN.

Association of serum uric acid with benefits of intensive blood pressure control

INTRODUCTION AND OBJECTIVES

Intensive systolic blood pressure (SBP) control improved outcomes in the Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial. Whether the serum uric acid concentration at baseline alters the benefits of intensive SBP control is unknown.

METHODS

The STEP trial was a randomized controlled trial that compared the effects of intensive (SBP target of 110 to<130mmHg) and standard (SBP target of 130 to <150mmHg) SBP control in Chinese patients aged 60 to 80 years with hypertension. The primary outcome was a composite of cardiovascular disease events. This post hoc analysis was performed to examine whether the effects of intensive SBP intervention differed by the baseline uric acid concentration using 2 models: restricted cubic spline curves and subgroup analyses, both based on the Fine-Gray subdistribution hazard model in the analysis of the primary outcome and secondary outcomes (excluding all-cause death). In the analysis of all-cause death, the Cox regression model was used. We also examined the change in the follow-up uric acid concentrations.

RESULTS

Overall, the risk of the primary outcome rose as the cumulative uric acid concentration increased in both the intensive and standard treatment groups. Patients with intensive treatment had a lower multivariable-adjusted subdistribution hazard ratio for the primary outcome, but with a wide overlap of 95%CI. Next, we stratified patients according to their baseline uric acid concentration (tertile 1 [T1], <303.0μmol/L; tertile 2 [T2], 303.0 to <375.8μmol/L; and tertile 3 [T3], ≥375.8μmol/L). Subgroup analyses using tertiles provided HRs and 95%CI in T1 (HR, 0.55; 95%CI, 0.36-0.86; P=.008), T2 (HR, 0.80; 95%CI, 0.56-1.14; P=.22) and T3 (HR, 0.86; 95%CI, 0.60-1.21; P=.39), with an interaction P value of .29. The results for most of the secondary outcomes followed the same trends.

CONCLUSIONS

There was no evidence that the benefit of the intensive SBP control differed by baseline uric acid concentrations. This trial was registered at ClinicalTrial.gov (Identifier: NCT03015311).

Uric acid and blood pressure in NHANES dated from 2009 to 2018: A cross-sectional research

BACKGROUND AND AIM

This study aimed to explore the association between uric acid (UA) and blood pressure (BP), included systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP).

METHODS AND RESULTS

A cross-sectional study with 22,478 individuals aged from 12 to 80 years (11,443 males and 11,035 females) from the National Health and Nutrition Examination Survey (NHANES) was performed. Multiple linear regression analysis was applied to explore the relationship between UA and BP, Stratified analysis and interaction were performed based on gender, race, age, body mass index (BMI), and alcohol consumption. Significantly positively associations were presented in SBP(β, 0.84 [95% CI, 0.67, 1.00]), DBP(β, 0.23 [95% CI, 0.11, 0.36]), and MAP (β, 0.43 [95% CI, 0.31, 0.55]). The associations were much more stronger between UA and SBP in females (β, 1.04 [95% CI, 0.78, 1.30], p for interaction 0.0003), black group (β, 1.17 [95% CI, 0.77, 1.56], p for interaction 0.0296), age (≥45) group (β, 1.03 [95% CI, 0.68, 1.39], p for interaction <0.0001) and drinking group (β, 0.98 [95% CI, 0.75, 1.21], p for interaction <0.0001). The significant interactions were found between UA and DBP in gender and alcohol consumption (all p for interaction <0.05). In terms of MAP, the significant interactions were found in race, age, and alcohol consumption (all p for interaction <0.05).

CONCLUSIONS

A significantly positively association was found between UA and BP, including SBP, DBP, and MAP.

Hyperuricemia enhances procoagulant activity of vascular endothelial cells through TMEM16F regulated phosphatidylserine exposure and microparticle release

The link between serum uric acid (SUA) and the risk of venous thromboembolism (VTE) is well established. Recent data suggested a causative role of UA in endothelial cells (ECs) dysfunction. However, the molecular mechanism of high UA on thrombogenesis is unknown. We investigate whether high UA induce phosphatidylserine (PS) externalization and microparticle (MP) shedding in cultured EC, and contribute to UA-induced hypercoagulable state. In the present study, we demonstrate that UA induces PS exposure and EMP release of EC in a concentration- and time-dependent manner, which enhances the procoagulant activity (PCA) of EC and inhibited over 90% by lactadherin in vitro. Furthermore, hyperuricemic rat model was used to evaluate the development of thrombi following by flow stasis in the inferior vena cava (IVC). Hyperuricemia group is more likely to form large and hard thrombi compared with control. Importantly, we found that TMEM16F expression is significantly upregulated in UA-treated EC, which is crucial for UA-induced PS exposure and MP formation. Additionally, UA increases the generation of reactive oxygen species (ROS), lipid peroxidation, and cytosolic Ca2+ concentration in EC, which might contribute to increased TMEM16F expression. Using confocal microscopy, we also observed disruption of the actin cytoskeleton, suggesting that depolymerization of actin filaments might be required for TMEM16F activation and followed by PS exposure and membrane blebbing in UA-treated EC. Our results demonstrate a thrombotic role of EC in hyperuricemia through TMEM16F-mediated PS exposure and MPs release.

Hyperuricemia and Its Associated Factors Among Adult Staff Members of the Ethiopian Public Health Institute, Ethiopia

Background

Hyperuricemia is related not only to an increased risk of gouty arthritis but also to an increased risk of cardiovascular diseases, resistant hypertension, insulin resistance and progression of type 2 diabetes mellitus. However, to the best of our knowledge, the prevalence of hyperuricemia and its associated factors have rarely been assessed in Ethiopian populations. Therefore, this study aimed to determine the prevalence of hyperuricemia and its associated factors among adult staff members of the Ethiopian Public Health Institute.

Methods

An institution-based cross-sectional study was conducted from July 1 to October 28, 2018. A total of 402 study participants were selected using a simple random sampling technique. An interviewer-administered questionnaire was used to collect the data. A blood sample of approximately 5 mL was collected from each study participant after overnight fasting through standardized methods for biochemical tests, and analyses were carried out with an automated COBAS 6000 analyzer. Data analysis was performed by SPSS version 20 software. The factors associated with the outcome variable were identified by bivariable and multivariable logistic regression analyses, and a p value <0.05 was used to declare statistical significance.

Results

The mean age of the study participants was 37.13±10.5 (mean ± SD), and 51.5% of the participants were male. The overall prevalence of hyperuricemia (>5.7 mg/dL for females and >7 mg/dL for males) was found to be 31.0%. The multivariable logistic analysis revealed that age (AOR=1.59, 95% CI 1.01–2.78), sex (AOR=1.66, 95% CI 1.02–2.70), cigarette smoking (AOR=2.05, 95% CI 1.01–4.19) and serum low-density lipoprotein (LDL) (AOR=1.70, 95% CI 1.01–2.87) were significantly associated with hyperuricemia.

Conclusion

The prevalence of hyperuricemia was relatively high compared to similar studies. Early screening for hyperuricemia in the general population, especially in those who are smokers, of older age and with high serum LDL levels, is vital to control its adverse effects at an early stage.

Prevalence of Hyperuricemia and the Use of Allopurinol in Older Poles-Results from a Population-Based PolSenior Study

BACKGROUND

Our study analyzes the frequency and risk factors of hyperuricemia and the use of allopurinol in a representative cohort of the older Polish adult population.

METHODS

The analysis was a part of a cross-sectional PolSenior study on aging in Poland. The complete medication data were available in 4873 out of 4979 community dwelling respondents aged 65 and over. Serum uric acid concentrations were evaluated in 4028 participants (80.9% of the cohort).

RESULTS

Hyperuricemia was observed in 28.2% of women and 24.7% of men. Ten risk factors of hyperuricemia were selected based on multivariable LASSO logistic regression analysis. Nine factors showed significant odds ratios: eGFR < 60 mL/min/1.73 m2 (OR = 4.10), hypertriglyceridemia (OR = 1.88), obesity (OR = 1.75), heart failure (1.70), CRP > 3.0 mg/dL (OR = 1.64), coronary artery disease (OR = 1.30), use of loop-diuretics (OR = 4.20), hydrochlorothiazide (OR = 2.96), and thiazide-like diuretics (OR = 2.81). Allopurinol was used by 2.8% of men and 1.8% of women. The therapy was considered effective in 46.7% of men and 53.3% of women.

CONCLUSIONS

Hyperuricemia was present in 23.1% (95% CI: 21.8-24.4) of the older Polish population. The frequency of hyperuricemia increases with age, reaching 30.5% in men and 33.7% in women aged 90 years or more. Chronic kidney disease, obesity, heart failure, hypertriglyceridemia, and the use of diuretics were the strongest risk factors for hyperuricemia in older adults. The treatment with allopurinol was ineffective in more than half of participants.

Uric acid and hypertension: a focused review and practical recommendations

: Uric acid levels are higher in humans than in other mammals. Best known as an extracellular antioxidant, uric acid also increases salt sensitivity, fat storage, and lipogenesis. Xanthine oxidase-related oxidative stress may also induce endothelial dysfunction and renal vasoconstriction. Renal structure abnormalities contribute to salt-sensitive and uric acid-independent hypertension. Maternal hyperuricemia during pregnancy and hyperuricemia early in life are likewise independent risk factors for hypertension. Genetic polymorphism is potentially involved in the activity of xanthine oxidoreductase, but further studies are needed. Xanthine oxidase inhibition consistently decreases blood pressure in younger hypertensive patients, albeit modestly. Hyperuricemia affects one out of five adults as a result of the Western diet, insulin resistance, and renal dysfunction. This review advocates lifestyle changes to maintain uric acid levels within the normal range in young (pre)hypertensive individuals or normotensives with a family history of hypertension, metabolic disorders, or obesity; moreover, antihypertensive medications that increase uric acid levels should be avoided.

Hyperuricemia and Hypertension: Links and Risks

Hyperuricemia has long been recognized to be associated with increased cardiovascular risk, including risk of developing hypertension. Epidemiological findings suggest that the link with hypertension is stronger in children and adolescents. Uric acid acts as a strong antioxidant compound in the extracellular environment but has pro-inflammatory effects within the intracellular setting. A chronic phase of microvascular injury is known to occur after prolonged periods of hyperuricemia. This is proposed to contribute to afferent arteriolopathy and elevation of blood pressure that may become unresponsive to uric acid-lowering therapies over time. Studies have struggled to infer direct causality of hyperuricemia due to a vast number of confounders including body mass index. The aim of this review is to present the available data and highlight the need for large scale prospective randomized controlled trials in this area. At present, there is limited evidence to support a role for uric acid-lowering therapies in helping mitigate the risk of hypertension.

Does obesity modify the epidemiological association between hyperuricemia and the prevalence of hypertension among Northern Chinese community-dwelling people? A Chinese population-based study

OBJECTIVES

Hyperuricemia and obesity both play a role in the development of hypertension. However, limited evidence is available for the combined effect of hyperuricemia and obesity on the prevalence of hypertension in the Chinese population. We aimed to assess the separate and combined effects of these two risk factors on the risk of hypertension.

METHODS

We conducted a cross-sectional study in an area of Dalian city, Liaoning Province, China, from September 2015 to November 2016; 8700 adult residents were invited to participate in this study. Hyperuricemia was defined as serum uric acid ≥ 416 μmol/L in men and ≥ 357 μmol/L in women according to the guidelines. Individuals were categorised into four groups: the control group (body mass index (BMI) §amp;lt; 25 without hyperuricemia, the reference group), the obesity group (BMI ≥ 25 without hyperuricemia), the hyperuricemia group (BMI §amp;lt; 25 with hyperuricemia) and the obese-hyperuricemia group (BMI ≥ 25 with hyperuricemia). A multivariable logistic model was used to investigate individual and combined effects of hyperuricemia and obesity on the risk of hypertension.

RESULTS

Of the 8331 individuals included, 44.3% were obese, 13.6% suffered from hyperuricemia, and 7.8% were both obese and hyperuricemic. The hypertension prevalence was the highest in the obese-hyperuricemia group (55.5% (95% CI 51.6% to 59.2%)), followed by that in the obesity (44.3% (42.6% to 46.1%)) and that in the hyperuricemia groups (33.5% (29.5% to 37.9%)). After adjusting for confounders, the obese-hyperuricemia group had a nearly threefold increased risk of hypertension compared with their healthy counterparts (OR 2.98 (2.48 to 3.57)). This pattern was also observed in the obesity group with a higher risk of hypertension (OR 2.18 (1.96 to 2.42)) compared with the control group, whereas the risk of hypertension was not elevated significantly in the hyperuricemia group (OR 1.14 (0.92 to 1.42)).

CONCLUSION

Our study provided the first evidence that obese Chinese individuals with hyperuricemia had a significantly increased risk of hypertension compared with their healthy counterparts. This combined effect on the risk of hypertension is much stronger than the individual effect of either factor.

Hypertriglyceridemia and hyperuricemia: a retrospective study of urban residents

Background

The aim of this study was to determine the association between hypertriglyceridemia and hyperuricemia (HUA).

Methods

The study was conducted in 3884 subjects who had not received medication enrolled as a baseline. Each participant received at least three annual health check-ups between 2011 and 2017. The risk of hyperuricemia was assessed in four Quartiles (Q1 to Q4) according to TG levels using multivariate-adjusted logistic regression models.

Results

The total incidence rate of HUA was 62.3/1000 person-years. In the univariate analysis, the risk of hyperuricemia in people with hypertriglyceridemia was 2.353 times that of normal triglycerides, with a 95% confidence interval of (2.011, 2.754), and the risk of hyperuricemia in men was 1.86 times of female, and the 95% confidence interval is (1.634, 2.177). After adjusting the potential confounders, the relative risk RR of TG at Q2 Q3 Q4 was 1.445 (95%CI:1.114, 1.901), 2.075 (1.611, 2.674), 2.972 (2.322, 3.804).

Conclusions

TG is an independent risk factor for hyperuricemia. As the level of TG increases, the risk of HUA increases.

Frequency of Hyperuricemia and its Risk Factors in the Adult Population

Introduction

Hyperuricemia (HU) does not only predispose to gouty arthritis but also increases the risk of major cardiovascular events and chronic kidney disease and decreases the overall quality of life. Although the incidence of hyperuricemia is increasing in the Asian population, prevalence studies from healthy asymptomatic adults are still scarce. The aim of this study was to determine the frequency of HU in the general population of Karachi, Pakistan.

Methods

A cross-sectional study was conducted in various out-patient clinics across Karachi in January 2019. Serum uric acid (SUA) levels were recorded using UASure Blood Uric Acid Monitoring System. Age, gender, body mass index (BMI), the frequency of activity, the frequency of meat consumption, and the presence of hypertension were noted. For hypertensives, the use of thiazide diuretics was noted. Data were entered and analyzed using SPSS v. 22. 

Results

This study was completed by 375 individuals including 208 (55.5%) men and 167 (44.5%) women. Their mean age was 48.78 ± 13.399 years and the mean SUA level was 5.92 ± 1.73 mg/dl. There were 83 (39.9%) men and 30 (17.9%) women with elevated SUA levels. The overall prevalence of HU was 30.1%. Patient characteristics including gender, hypertension, the use of diuretics frequency of meat consumption, sedentary lifestyle, and BMI showed statistical significance with mean SUA levels. Eta-squared indicated a weak effect of SUA with gender, age, and use of thiazide diuretics. A moderate effect was seen with hypertension, the frequency of meat consumption, sedentary lifestyle, and BMI.

Conclusion

Hyperuricemia is a health hazard and its incidence is high in Pakistan. Patients who have risk factors for elevated SUA levels must be monitored for hyperuricemia at regular intervals.

Physiology of Hyperuricemia and Urate-Lowering Treatments

Gout is the most common form of inflammatory arthritis and is a multifactorial disease typically characterized by hyperuricemia and monosodium urate crystal deposition predominantly in, but not limited to, the joints and the urinary tract. The prevalence of gout and hyperuricemia has increased in developed countries over the past two decades and research into the area has become progressively more active. We review the current field of knowledge with emphasis on active areas of hyperuricemia research including the underlying physiology, genetics and epidemiology, with a focus on studies which suggest association of hyperuricemia with common comorbidities including cardiovascular disease, renal insufficiency, metabolic syndrome and diabetes. Finally, we discuss current therapies and emerging drug discovery efforts aimed at delivering an optimized clinical treatment strategy.

Febuxostat attenuates ER stress mediated kidney injury in a rat model of hyperuricemic nephropathy

Hyperuricemia contributes to kidney tubular injury and kidney fibrosis. However, the underlying mechanism remains unclear. Here we examined the role of RTN1A, a novel endoplasmic reticulum (ER)-associated protein and ER stress in hyperuricemic nephropathy. We first found the expression of RTN1A and ER stress markers was significantly increased in kidney biopsies of hyperuricemia patients with kidney injury. In a rat model of hyperuricemic nephropathy (HN) established by oral administration of a mixture of adenine and potassium oxonate, increased expression of RTN1A and ER stress was shown in tubular and interstitial compartment of rat kidneys. Treatment of Febuxostat, a new selective inhibitor of xanthine oxidase (XO), not only attenuated renal tubular injury and tubulointerstitial fibrosis, but also reduced uric acid crystals deposition in HN rat kidneys. In vitro, Febuxostat also reduced ER stress and apoptosis in uric acid treated tubular epithelial cells. Our data suggest that RTN1A and ER stress mediate tubular cell injury and kidney fibrosis in HN. Urate-lowering therapy (ULT) with Febuxostat attenuates uric-acid induced ER stress in renal tubular cells and the progression of HN.

The problem of cardio-renal diseases in patients with gout

BACKGROUNDS

Although evidence is mounting on the role of hyperuricemia in cardio-renal disease, continuing doubt remains as to whether hyperuricemia can be considered a major causal cardiovascular risk factor. In addition, available data suggest that treatment may be beneficial, even in the absence of overt gout, when hyperuricemia accompanies other clinical conditions, such as urate deposition, advanced chronic kidney disease, or cardiovascular risk factors.

METHODS AND RESULTS

Analysis of the literature suggests there would be sufficient evidence warranting clinical trials to determine whether lowering uric acid levels would be clinically beneficial in the prevention or treatment of cardiovascular and renal diseases.

CONCLUSION

Under a practical profile, it becomes progressively more important to investigate the possibility of reducing serum uric acid levels in the general population below the level of 5.0 mg/dL.