Uric acid: from a biological advantage to a potential danger. A focus on cardiovascular effects.
Cortese Francesca,Giordano Paola,Scicchitano Pietro,Faienza Maria Felicia,De Pergola Giovanni,Calculli Giacinto,Meliota Giovanni,Ciccone Marco Matteo
Non-communicable diseases represent nowadays the most common cause of death worldwide, having largely overcome infectious diseases. Among them, cardiovascular diseases constitute the majority. Given these premise, great efforts have been made by scientific societies to emphasize the fundamental role of cardiovascular prevention and risk factors control. In addition to classical cardiovascular risk factors such as smoking, arterial hypertension, hypercholesterolemia and male gender, new risk factors are emerging from international literature. Among them, uric acid is the protagonist. Several evidences show a direct role of hyperuricemia in the determinism of metabolic and vascular disorders. From the other hand, some researchers have demonstrated that uric acid is only a marker of cardiovascular damage and not a risk factor for its development. Aim of this review is to evaluate the scientific evidences on the role of uric acid in cardiovascular diseases in order to shed light on this confusing topic.
Vascular Consequences of Hyperuricemia and Hypouricemia.
Albert Daniel,Scudder Paige N,Bagley Pamela,Saag Kenneth G
Rheumatic diseases clinics of North America
There are more than 10,000 articles in the literature published since 1999 that appear in a search of hyperuricemia and hypouricemia for vascular events. Systematic reviews were reviewed for this time frame, numbering approximately 300 articles in addition to more than 400 reports of randomized clinical trials published since 2017. In summary, the epidemiologic associations of hyperuricemia and hypouricemia with vascular disease are confounded by comorbid conditions. The interventional data are suggestive of a relationship of gout and vascular disease and to a lesser extent hyperuricemia and hypertension; however, more interventional studies are necessary to confirm these relationships.
The effect of polymorphism of uric acid transporters on uric acid transport.
Wang Ze,Cui Tao,Ci Xiaoyan,Zhao Fang,Sun Yinghui,Li Yazhuo,Liu Rui,Wu Weidang,Yi Xiulin,Liu Changxiao
Journal of nephrology
The abnormal metabolism of uric acid results in many disease such as chronic kidney disease, hyperuricemia, nephrolithiasis, gout, hypertension, vascular disease and so on. Serum uric acid levels are maintained by the balance between production and elimination. There are many factors that maintain the balance of serum uric acid. One of them is transporters which are responsible for the debouchment of uric acid within blood. The transport and excretion of uric acid is a complicated procedure which is related with various transporters such as OAT1, OAT3, OAT4, URAT1, GLUT9, BCRP, MRP4, NPT1, NTP4, and so on. In recent years, a large number of genome-wide association studies have shown that the single nucleotide polymorphisms of uric acid transporters were closely related to serum uric acid level. What's more, some mutations on these gene locus may also break the balance of serum uric acid. Here, the polymorphisms of uric acid transporters closely related with the serum uric acid balance were reviewed and discussed because of their important significance in clinical therapy for a precision medicine. The mechanism of metabolic diseases with gene variation may provide new strategy for the design and development of innovative drug to treat diseases with uric acid metabolic disturbance.
Cardiovascular Safety of Urate Lowering Therapies.
Kang Eun Ha,Kim Seoyoung C
Current rheumatology reports
PURPOSE OF REVIEW:The effect of urate lowering treatment (ULT) on cardiovascular (CV) risk and mortality in gout has been a topic of interest. This review discusses the CV effect of ULT and comparative CV safety among ULT agents. RECENT FINDINGS:The mechanism linking gout with CV risk is not fully understood but seems multifactorial involving hyperuricemia, xanthine oxidase (XO), oxidative stress, and chronic inflammation. Conflicting data exist regarding CV benefits of ULT in adults with and without hyperuricemia. Although meta-analyses on randomized controlled trials (RCTs) suggest CV benefits with allopurinol, few high-quality RCTs have examined the CV effect of ULT among patients with hyperuricemia or gout. The recent CARES trial adds new information on comparative CV safety between two XO inhibitors (XOIs), febuxostat and allopurinol, in patients with gout. It remains unclear whether ULT reduces CV risk in patients with gout or hyperuricemia. Comparative CV safety studies of XOIs suggest that additional mechanisms beyond urate-lowering effect or XO inhibition are likely involved in CV risk modification in patients with gout. Ongoing RCTs of ULT may be able to further determine the effect of ULT on CV risk.
Cardiovascular Disease in Gout and the Protective Effect of Treatments Including Urate-Lowering Therapy.
Gupta Manik K,Singh Jasvinder A
Cardiovascular disease affects more than 90 million Americans. Recent studies support an increased cardiovascular disease risk in inflammatory conditions, such as gout. Increased serum urate levels, or hyperuricemia, are a precursor to gout. Data from meta-analyses have shown hyperuricemia to be linked to hypertension and coronary heart disease. Similarly, gout has been associated with an increased risk of myocardial infarction, cerebrovascular accidents, and death from cardiovascular disease in randomized clinical trials. Urate-lowering therapy reduces serum urate and may decrease systemic inflammation, generation of oxidative species, and reverses endothelial dysfunction through hyperuricemia-dependent or hyperuricemia-independent pathways. Cardioprotective benefits of allopurinol, a first-line agent for the treatment of gout, have been demonstrated to potentially prevent myocardial infarction, stroke, atrial fibrillation, and other cardiovascular diseases in observational studies in select populations. Randomized controlled trials (RCTs) have also examined the role of newer urate-lowering therapies, such as febuxostat and lesinurad, and their risk of cardiovascular-specific mortality in comparison to allopurinol. A large post-marketing study of febuxostat vs. allopurinol showed higher all-cause and cardiovascular-specific mortality in the febuxostat group than in the allopurinol group; a major study limitation was that large numbers of patients were lost to follow-up or discontinued treatment. RCTs are required to assess the comparative effectiveness of urate-lowering therapies, validate findings of observational studies, and to determine which subgroup populations of gout are most likely to benefit from appropriate long-term urate-lowering therapy. This review examines the data for increased cardiovascular disease in gout and potential underlying mechanisms (including hyperuricemia, inflammation, endothelial dysfunction, oxidative stress) and the effect of urate-lowering therapy on cardiovascular disease.
Hyperuricemia and endothelial function: From molecular background to clinical perspectives.
Maruhashi Tatsuya,Hisatome Ichiro,Kihara Yasuki,Higashi Yukihito
Uric acid is the end product of purine metabolism catalyzed by xanthine oxidase in humans. In the process of purine metabolism, reactive oxygen species, including superoxide, are generated concomitantly with uric acid production, which may deteriorate endothelial function through the reaction of superoxide with nitric oxide (NO), leading to decreased NO bioavailability and increased production of peroxynitrite, a reactive oxidant. Therefore, xanthine oxidase may be a therapeutic target in the treatment of endothelial dysfunction. Indeed, clinical studies have shown that endothelial dysfunction is restored by treatment with a xanthine oxidase inhibitor in patients with cardiovascular risk factors. However, it has not been fully determined whether uric acid per se is an independent causal risk factor of endothelial dysfunction in humans. Although experimental studies have indicated that uric acid absorbed into endothelial cells via the activation of uric acid transporters expressed in endothelial cells causes endothelial dysfunction through increased oxidative stress and inflammation, an actual biological effect of uric acid on endothelial function in vivo has not been fully elucidated, in part, because of the difficulty in investigating the effect of uric acid alone on endothelial function due to the close associations of uric acid with other conventional cardiovascular risk factors and the complicated relationship between uric acid and endothelial function attributed to the potent antioxidant properties of uric acid. In this review, we focus on the relationship between uric acid and endothelial function from molecular to clinical perspectives.
Recent advances on uric acid transporters.
Xu Liuqing,Shi Yingfeng,Zhuang Shougang,Liu Na
Uric acid is the product of purine metabolism and its increased levels result in hyperuricemia. A number of epidemiological reports link hyperuricemia with multiple disorders, such as kidney diseases, cardiovascular diseases and diabetes. Recent studies also showed that expression and functional changes of urate transporters are associated with hyperuricemia. Uric acid transporters are divided into two categories: urate reabsorption transporters, including urate anion transporter 1 (URAT1), organic anion transporter 4 (OAT4) and glucose transporter 9 (GLUT9), and urate excretion transporetrs, including OAT1, OAT3, urate transporter (UAT), multidrug resistance protein 4 (MRP4/ABCC4), ABCG-2 and sodium-dependent phosphate transport protein. In the kidney, uric acid transporters decrease the reabsorption of urate and increase its secretion. These transporters' dysfunction would lead to hyperuricemia. As the function of urate transporters is important to control the level of serum uric acid, studies on the functional role of uric acid transporter may provide a new strategy to treat hyperuricemia associated diseases, such as gout, chronic kidney disease, hyperlipidemia, hypertension, coronary heart disease, diabetes and other disorders. This review article summarizes the physiology of urate reabsorption and excretion transporters and highlights the recent advances on their roles in hyperuricemia and various diseases.
Uric acid in the pathogenesis of metabolic, renal, and cardiovascular diseases: A review.
Sharaf El Din Usama A A,Salem Mona M,Abdulazim Dina O
Journal of advanced research
The association between uric acid (UA) on one side and systemic hypertension (Htn), dyslipidemia, glucose intolerance, overweight, fatty liver, renal disease and cardiovascular disease (CVD) on the other side is well recognized. However, the causal relationship between UA and these different clinical problems is still debatable. The recent years have witnessed hundreds of experimental and clinical trials that favored the opinion that UA is a probable player in the pathogenesis of these disease entities. These studies disclosed the strong association between hyperuricemia and metabolic syndrome (MS), obesity, Htn, type 2 diabetes mellitus (DM), non-alcoholic fatty liver disease, hypertriglyceridemia, acute kidney injury, chronic kidney disease (CKD), coronary heart disease (CHD), heart failure and increased mortality among cardiac and CKD patients. The association between UA and nephrolithiasis or preeclampsia is a non-debatable association. Recent experimental trials have disclosed different changes in enzyme activities induced by UA. Nitric oxide (NO) synthase, adenosine monophosphate kinase (AMPK), adenosine monophosphate dehydrogenase (AMPD), and nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase are affected by UA. These changes in enzymatic activities can lead to the observed biochemical and pathological changes associated with UA. The recent experimental, clinical, interventional, and epidemiologic trials favor the concept of a causative role of UA in the pathogenesis of MS, renal, and CVDs.
Uric acid lowering therapy in cardiovascular diseases.
Volterrani Maurizio,Iellamo Ferdinando,Sposato Barbara,Romeo Franco
International journal of cardiology
Recent evidence would indicate that high serum uric acid (SUA) levels can be a significant and independent risk factor for hypertension and cardiovascular diseases, such as ischemic heart disease and heart failure. In the last few years an independent risk relationship between hyperuricemia, cardiovascular disease and mortality has also been reported. Hyperuricemia has been shown as an independent risk factor for acute myocardial infarction and an independent and conjoint association of either gout and SUA with total and cardiovascular mortality has been reported, with mortality impact in gout patients increasing with rising SUA concentrations, even for SUA levels in the normal to high range. These findings prompted a growing research interest on the possible benefits of uric acid lowering drugs in cardiovascular diseases. Indeed, clinical studies have reported on the beneficial effects of uric acid lowering drugs, in particular of xanthine oxidase inhibitors, in hypertension, ischemic heart disease and heart failure. Two main mechanisms have been claimed to explain the dangerous effects of hyperuricemia and, as a consequence, the benefits of uric acid lowering therapy: endothelial dysfunction and systemic inflammation. This brief review aims to summarize current evidence from human studies on the role of acid uric lowering therapy in cardiovascular diseases for practical and clinical purposes. The possible mechanisms underlying the benefits of acid uric lowering therapy are also addressed.
Cardiovascular disease in autoimmune rheumatic diseases.
Hollan Ivana,Meroni Pier Luigi,Ahearn Joseph M,Cohen Tervaert J W,Curran Sam,Goodyear Carl S,Hestad Knut A,Kahaleh Bashar,Riggio Marcello,Shields Kelly,Wasko Mary C
Various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis, spondyloarthritis, vasculitis and systemic lupus erythematosus, are associated with premature atherosclerosis. However, premature atherosclerosis has not been uniformly observed in systemic sclerosis. Furthermore, although experimental models of atherosclerosis support the role of antiphospholipid antibodies in atherosclerosis, there is no clear evidence of premature atherosclerosis in antiphospholipid syndrome (APA). Ischemic events in APA are more likely to be caused by pro-thrombotic state than by enhanced atherosclerosis. Cardiovascular disease (CVD) in ARDs is caused by traditional and non-traditional risk factors. Besides other factors, inflammation and immunologic abnormalities, the quantity and quality of lipoproteins, hypertension, insulin resistance/hyperglycemia, obesity and underweight, presence of platelets bearing complement protein C4d, reduced number and function of endothelial progenitor cells, apoptosis of endothelial cells, epigenetic mechanisms, renal disease, periodontal disease, depression, hyperuricemia, hypothyroidism, sleep apnea and vitamin D deficiency may contribute to the premature CVD. Although most research has focused on systemic inflammation, vascular inflammation may play a crucial role in the premature CVD in ARDs. It may be involved in the development and destabilization of both atherosclerotic lesions and of aortic aneurysms (a known complication of ARDs). Inflammation in subintimal vascular and perivascular layers appears to frequently occur in CVD, with a higher frequency in ARD than in non-ARD patients. It is possible that this inflammation is caused by infections and/or autoimmunity, which might have consequences for treatment. Importantly, drugs targeting immunologic factors participating in the subintimal inflammation (e.g., T- and B-cells) might have a protective effect on CVD. Interestingly, vasa vasorum and cardiovascular adipose tissue may play an important role in atherogenesis. Inflammation and complement depositions in the vessel wall are likely to contribute to vascular stiffness. Based on biopsy findings, also inflammation in the myocardium and small vessels may contribute to premature CVD in ARDs (cardiac ischemia and heart failure). There is an enormous need for an improved CVD prevention in ARDs. Studies examining the effect of DMARDs/biologics on vascular inflammation and CV risk are warranted.
[Hyperuricemia and cardiovascular continuum].
Larina V N,Bart B Ia,Larin V G,Donskov A S
Many recent reports suggest the relationship between hyperuricemia, risk and prognosis of arterial hypertension and coronary heart disease. The works on the clinical and prognostic significance in chronic heart failure are few even if this pathology deteriorates prognosis of some cardiovascular diseases. Hyperuricemia is considered to be a component of cardiovascular continuum, risk factor of chronic heart failure and marker of its unfavourable outcome. Prognostic significance of hyperuricemia in patients with chronic heart failure is discussed.
Relationships among hyperuricemia, endothelial dysfunction and cardiovascular disease: molecular mechanisms and clinical implications.
Puddu Paolo,Puddu Giovanni M,Cravero Eleonora,Vizioli Luca,Muscari Antonio
Journal of cardiology
Uric acid is the end product of purine metabolism. Its immediate precursor, xanthine, is converted to uric acid by an enzymatic reaction involving xanthine oxidoreductase. Uric acid has been formerly considered a major antioxidant in human plasma with possible beneficial anti-atherosclerotic effects. In contrast, studies in the past two decades have reported associations between elevated serum uric acid levels and cardiovascular events, suggesting a potential role for uric acid as a risk factor for atherosclerosis and related diseases. In this paper, the molecular pattern of uric acid formation, its possible deleterious effects, as well as the involvement of xanthine oxidoreductase in reactive oxygen species generation are critically discussed. Reactive oxygen species contribute to vascular oxidative stress and endothelial dysfunction, which are associated with the risk of atherosclerosis. Recent studies have renewed attention to the xanthine oxidoreductase system, since xanthine oxidoreductase inhibitors, such as allopurinol and oxypurinol, would be capable of preventing atherosclerosis progression by reducing endothelial dysfunction. Also, beneficial effects could be obtained in patients with congestive heart failure. The simultaneous reduction in uric acid levels might contribute to these effects, or be a mere epiphenomenon of the drug action. The molecular mechanisms involved are discussed.
Improvement of LVEF in patients with HFrEF with coronary heart disease after revascularization-A real-world study.
Peng Ding,Liu Jing-Hua
Journal of interventional cardiology
OBJECTIVE:This study aimed to explore the predictive factors for left ventricular ejection fraction (LVEF) improvement after revascularization. METHODS:This real-world study examined 993 patients with ischemic HFrEF who had received revascularization (PCI or CABG), had survived at least 90 days and had undergone an echocardiography review. Based on the change in the LVEF, we divided the patients into two groups. RESULT:We obtained 454 patients with ≥10% improvement and 539 with <10% improvement or deterioration. By Cox regression analysis, we obtained five independent factors for LVEF improvement, including female (P = 0.018, OR 0.726, 95% CI 0.557-0.947), prior MI (P = 0.000, OR 0.590, 95% CI 0.476-0.732), LVEF (P = 0.008, OR 0.967, 95% CI 0.943-0.991), digoxin (P = 0.027, OR 0.708, 95% CI 0.521-0.961), loop diuretic (P = 0.000, OR 1.515, 95% CI 1.208-1.901), and triple-vessel disease (P = 0.000, OR 1.462, 95% CI 1.192-1.792). By multivariate generalized estimation, we obtained seven factors associated with the degree of improvement, namely, low LVEF, short LVESD, short LVEDD, no prior MI, no hyperuricemia, clopidogrel use and triple-vessel disease. CONCLUSIONS:The method of revascularization (PCI vs CABG) had no effect on LVEF improvement. Patients with severely impaired baseline LVEFs, triple-vessel disease, or no history of MI tended to exhibit marked LVEF improvement (≥10%) after revascularization. In addition, LVESD, LVEDD, hyperuricemia, clopidogrel use and loop diuretic affected the degree of improvement.
Hyperuricemia predicts adverse clinical outcomes after cardiac resynchronization therapy.
Perge Péter,Boros András M,Zima Endre,Gellér László,Merkely Béla,Széplaki Gábor
Scandinavian cardiovascular journal : SCJ
OBJECTIVES:Changes in the levels of serum creatinine and N-terminal of prohormone brain natriuretic peptide (NT-proBNP) are useful risk markers after cardiac resynchronization therapy (CRT). The diagnostic value of changes in serum uric acid levels has been established in chronic heart failure, but no data are available on the prognostic value of hyperuricemia in a CRT population. DESIGN:We measured markers of renal function [creatinine, blood urea nitrogen (BUN) and uric acid] and NT-proBNP levels of 129 heart failure patients undergoing CRT in a prospective, observational study. The 5-year all-cause mortality and the 6-month clinical response (≥ 15% increase in the left ventricular ejection fraction) were considered as study end points. RESULTS:In multivariable analyses, the uric acid was found to be a statistically significant predictor of the outcome. Uric acid levels exceeding 386 mmol/L before CRT increased the chances of mortality [n = 55, hazard ratio = 2.39 (1.30-4.39), p < 0.01] and poor clinical response [n = 37, odds ratio = 2.89 (1.22-6.87), p = 0.01] independently of serum NT-proBNP and other factors. CONCLUSIONS:Elevated uric acid concentrations in patients with CRT are associated with an increased risk of mortality and poor clinical response independently of the NT-proBNP levels and other relevant clinical factors.
Prevalence of Hyperuricemia in Patients With Acute Heart Failure With Either Reduced or Preserved Ejection Fraction.
Palazzuoli Alberto,Ruocco Gaetano,De Vivo Oreste,Nuti Ranuccio,McCullough Peter A
The American journal of cardiology
The relation between uric acid (UA) and heart failure has been described; however, there is little detail concerning acute heart failure (AHF) in patients with reduced versus preserved ejection fraction heart failure (HFrEF, HFpEF). We studied 324 consecutive AHF patients screened from interventional Diur-HF Trial (NCT01441245) from January 2011 to February 2016, and divided into HFrEF (EF <50%) and HFpEF (EF ≥50%). We defined hyperuricemia as serum UA ≥7.0 mg/dL in men and ≥6 mg/dL in women. Patients were followed up for 6 months after discharge. The primary outcome was heart failure hospitalization or death. Among 173 HFrEF and 151 HFpEF cases, hyperuricemia was found in 43% and 57%, respectively (p = 0.01). Hyperuricemia was also more frequent in women (74% vs 60%; p = 0.008), those with diabetes (39% vs 19%; p <0.001), hypertension (62% vs 43%; p = 0.001), and atrial fibrillation (48% vs 34%; p = 0.01). In patients with HFrEF, univariate analysis found that hyperuricemia (hazard ratio [HR] 1.48, 95% confidence interval [CI] 1.02 to 2.15; p = 0.04) and congestion score ≥3 (HR 2.83, 95% CI 1.52 to 5.28; p <0.001) were associated with the primary end point; after adjustment, only congestion score ≥3 (HR 2.08, 95% CI 1.06 to 4.10; p = 0.03) confirmed this trend. Conversely, in patients with HFpEF, hyperuricemia was the only significant predictor of the primary end point both in univariate (HR 2.25, 95% CI 1.44 to 3.50; p <0.001) and multivariate analyses (HR 2.38, 95% CI 1.32 to 4.28; p = 0.004). In conclusion, in AHF hyperuricemia is common in both in HFrEF and in HFpEF. In the HFpEF subgroup, hyperuricemia was the only independent predictor of heart failure hospitalization or death.
Prognostic Significance of Hyperuricemia in Patients With Acute Heart Failure.
Palazzuoli Alberto,Ruocco Gaetano,Pellegrini Marco,Beltrami Matteo,Giordano Nicola,Nuti Ranuccio,McCullough Peter A
The American journal of cardiology
Serum uric acid (UA) is associated with death and hospitalization in chronic heart failure (HF). However, UA in acute HF has not been well studied with respect to its relation to renal dysfunction and vascular congestion. We measured admission serum UA along with baseline variables in 281 patients with acute HF screened from the Loop Diuretics Administration and Acute Heart Failure (Diur-HF) trial. Hyperuricemia was defined as serum UA >7 mg/dl in men and >6 mg/dl in women. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate <60 ml/min/1.73 m(2) before hospital admission. Death or HF hospitalization at 6 months was the primary outcome. The mean UA concentration was 6.4 ± 2.5 mg/dl, and 121 patients (43.1%) were classified as hyperuricemic. UA values were significantly increased in patients with CKD compared to patients without CKD (6.8 ± 2.7 vs 6.1 ± 2.1 mg/dl; p = 0.02); however, UA was not associated with the development of acute kidney injury. Patients with hyperuricemia had greater degrees of pulmonary and systemic congestion than normouricemic patients (congestion score 3.5 vs 2.1, p <0.01). Hyperuricemia was associated with higher risk of death or HF rehospitalization (univariate hazard ratio 1.46 [1.02 to 2.10]; p = 0.04, multivariate hazard ratio 1.69 [1.16 to 2.45]; p = 0.005). In conclusion, hospitalized patients with acute HF, elevated UA levels were associated with both CKD and pulmonary congestion. After controlling for potential confounders, hyperuricemia was associated with rehospitalization and death at 6 months.
Relationship of hyperuricemia with mortality in heart failure patients with preserved ejection fraction.
Shimizu Takeshi,Yoshihisa Akiomi,Kanno Yuki,Takiguchi Mai,Sato Akihiko,Miura Shunsuke,Nakamura Yuichi,Yamauchi Hiroyuki,Owada Takashi,Abe Satoshi,Sato Takamasa,Suzuki Satoshi,Oikawa Masayoshi,Yamaki Takayoshi,Sugimoto Koichi,Kunii Hiroyuki,Nakazato Kazuhiko,Suzuki Hitoshi,Saitoh Shu-ichi,Takeishi Yasuchika
American journal of physiology. Heart and circulatory physiology
Serum uric acid is a predictor of cardiovascular mortality in heart failure with reduced ejection fraction. However, the impact of uric acid on heart failure with preserved ejection fraction (HFpEF) remains unclear. Here, we investigated the association between hyperuricemia and mortality in HFpEF patients. Consecutive 424 patients, who were admitted to our hospital for decompensated heart failure and diagnosed as having HFpEF, were divided into two groups based on presence of hyperuricemia (serum uric acid ≥7 mg/dl or taking antihyperuricemic agents). We compared patient characteristics, echocardiographic data, cardio-ankle vascular index, and cardiopulmonary exercise test findings between the two groups and prospectively followed cardiac and all-cause mortality. Compared with the non-hyperuricemia group (n = 170), the hyperuricemia group (n = 254) had a higher prevalence of hypertension (P = 0.013), diabetes mellitus (P = 0.01), dyslipidemia (P = 0.038), atrial fibrillation (P = 0.001), and use of diuretics (P < 0.001). Cardio-ankle vascular index (8.7 vs. 7.5, P < 0.001) and V̇e/V̇co2 slope (34.9 vs. 31.9, P = 0.02) were also higher. In addition, peak V̇o2 (14.9 vs. 17.9 ml·kg(-1)·min(-1), P < 0.001) was lower. In the follow-up period (mean 897 days), cardiac and all-cause mortalities were significantly higher in those with hyperuricemia (P = 0.006 and P = 0.004, respectively). In the multivariable Cox proportional hazard analyses after adjustment for several confounding factors including chronic kidney disease and use of diuretics, hyperuricemia was an independent predictor of all-cause mortality (hazard ratio 1.98, 95% confidence interval 1.036-3.793, P = 0.039). Hyperuricemia is associated with arterial stiffness, impaired exercise capacity, and high mortality in HFpEF.
Effect of urate-lowering therapies on renal disease progression in patients with hyperuricemia.
Levy Gerald D,Rashid Nazia,Niu Fang,Cheetham T Craig
The Journal of rheumatology
OBJECTIVE:To evaluate the association between hyperuricemia and renal disease progression in a real-world, large observational database study. METHODS:We conducted a population-based retrospective cohort study identifying 111,992 patients with hyperuricemia (> 7 mg/dl) from a large medical group. The final cohort were ≥ 18 years old, urate-lowering therapy (ULT)-naïve, and had the following laboratory results available: at least 1 glomerular filtration rate (GFR) level before the index date and at least 1 serum uric acid (sUA) level and GFR in the followup 36-month period. The cohort was categorized into 3 groups: never treated (NoTx), ULT time receiving therapy of < 80% (< 80%), and ULT time receiving therapy of ≥ 80% (≥ 80%). Outcomes were defined as a ≥ 30% reduction in GFR from baseline, dialysis, or GFR of ≤ 15 ml/min. A subanalysis of patients with sUA < 6 mg/dl at study conclusion was performed. Cox proportional hazards regression model determined factors associated with renal function decline. RESULTS:A total of 16,186 patients met inclusion criteria. There were 11,192 NoTx patients, 3902 with < 80% time receiving ULT, and 1092 with ≥ 80% time receiving ULT. Factors associated with renal disease progression were age, sex, hypertension, diabetes, congestive heart failure, hospitalizations, rheumatoid arthritis, and higher sUA at baseline. Time receiving therapy was not associated with renal outcomes. Patients who achieved sUA < 6 mg/dl had a 37% reduction in outcome events (p < 0.0001; HR 0.63, 95% CI: 0.5-0.78). CONCLUSION:Hyperuricemia is an independent risk factor for renal function decline. Patients treated with ULT who achieved sUA < 6 mg/dl on ULT showed a 37% reduction in outcome events.
The independent impact of congestive heart failure status and diuretic use on serum uric acid among men with a high cardiovascular risk profile: a prospective longitudinal study.
Misra Devyani,Zhu Yanyan,Zhang Yuqing,Choi Hyon K
Seminars in arthritis and rheumatism
OBJECTIVE:To evaluate the independent impact of congestive heart failure (CHF) status (compensation or decompensation) on serum uric acid levels among men with high cardiovascular risk profile. METHOD:We analyzed 11,681 men from the Multiple Risk Factor Interventional Trial, using data prospectively collected at baseline and annually over 6 years (64,644 visits). We evaluated the impact of change in CHF status during study follow-up, as compared with study baseline, on hyperuricemia (serum uric acid ≥7 mg/dL) and serum uric acid levels, using generalized estimating equations, adjusting for age, race, weight, weight change, education, alcohol intake, diuretic use, hypertension, serum creatinine level, and dietary factors. Similarly, we evaluated the independent impact of change in diuretic use (initiation or discontinuation). RESULTS:At baseline, mean serum uric acid was 6.88 mg/dL. Compared with no change in CHF status, odds ratios of hyperuricemia were 1.67 (95% CI, 1.21 to 2.32) for CHF decompensation and 0.21 (95% CI, 0.08 to 0.55) for compensation. The corresponding uric acid differences were 0.41 (95% CI, 0.20 to 0.62) and -1.00 (95% CI, -1.72 to -0.27), respectively. The odds ratios for initiation and discontinuation of diuretic were 3.32 (95% CI, 3.06 to 3.61) and 0.39 (95% CI, 0.35 to 0.44). CONCLUSIONS:CHF decompensation and diuretic use are both independently associated with increased odds of hyperuricemia among men with a high cardiovascular risk profile, whereas CHF recovery and diuretic discontinuation are associated with substantially lower odds of hyperuricemia.
Uric acid level and allopurinol use as risk markers of mortality and morbidity in systolic heart failure.
Wu Audrey H,Ghali Jalal K,Neuberg Gerald W,O'Connor Christopher M,Carson Peter E,Levy Wayne C
American heart journal
BACKGROUND:Previous studies have not extensively examined the association of hyperuricemia and adverse outcomes in systolic heart failure (HF) in relation to xanthine oxidase inhibitor therapy. METHODS:The Prospective Randomized Amlodipine Survival Evaluation study included New York Heart Association class IIIB or IV patients with left ventricular ejection fraction <30%. For analysis, the population was divided into uric acid quartiles among nonallopurinol users (2.2-7.1, >7.1-8.6, >8.6-10.4, >10.4 mg/dL) and those using allopurinol. Multivariate Cox regression modeling was performed to identify predictors of mortality. Uric acid quartile and allopurinol groups were referenced to the lowest uric acid quartile. RESULTS:A total of 1,152 patients were included. In general, patients in the allopurinol group and in the highest uric acid quartile had indicators of more severe HF, including worse renal function and greater proportion of New York Heart Association class IV patients, and greater diuretic use. The allopurinol group and highest uric acid quartile had the highest total mortality (41.7 and 42.4 per 100 person-years, respectively) and combined morbidity/mortality (45.6 and 51.0 per 100 person-years, respectively). Allopurinol use and highest uric acid quartile were independently associated with mortality (hazard ratio [HR] 1.65, 95% CI 1.22-2.23, P = .001 and HR 1.35, 95% CI 1.07-1.72, P = .01, respectively) and combined morbidity/mortality (uric acid quartile 4 vs 1: HR 1.32, 95% CI 1.06-1.66, P = .02; allopurinol use: HR 1.48, 95% CI 1.11-1.99, P = .008). CONCLUSION:Elevated uric acid level was independently associated with mortality in patients with severe systolic HF, even when accounting for allopurinol use.
Uric acid-lowering treatment with benzbromarone in patients with heart failure: a double-blind placebo-controlled crossover preliminary study.
Ogino Kazuhide,Kato Masahiko,Furuse Yoshiyuki,Kinugasa Yoshiharu,Ishida Katsunori,Osaki Shuichi,Kinugawa Toru,Igawa Osamu,Hisatome Ichiro,Shigemasa Chiaki,Anker Stefan D,Doehner Wolfram
Circulation. Heart failure
BACKGROUND:Hyperuricemia is common in chronic heart failure (CHF), and it is a strong independent marker of prognosis. Upregulated xanthine oxidase (XO) activity and impaired renal excretion have been shown to account for increased serum uric acid (UA) levels in CHF. Therapeutic interventions with allopurinol to reduce UA levels by XO inhibition have been shown to be beneficial. Discussions are ongoing whether UA itself is actively involved or it is a mere marker of upregulated XO activity within CHF pathophysiology. Therefore, the aim of this study was to test the effect of lowering UA by uricosuric treatment without XO inhibition on hemodynamic and metabolic characteristics of CHF. Impaired renal excretion of UA was taken into account. METHODS AND RESULTS:Serum UA (SUA), urinary UA (uUA) excretion, and renal clearance test for UA (Cl(UA)) were measured in 82 patients with CHF. SUA was significantly increased compared with controls of similar age (control, 5.45+/-0.70 mg/dL; New York Heart Association I, 6.48+/-1.70 mg/dL; New York Heart Association II, 7.34+/-1.94 mg/dL; New York Heart Association III, 7.61+/-2.11 mg/dL; P<0.01). Patients with CHF showed lower uUA excretion and Cl(UA). On multivariate analysis, insulin, brain natriuretic peptide (P<0.01), and creatinine levels (P=0.05) showed independent correlation with SUA. The treatment effect of the uricosuric agent benzbromarone was tested in 14 patients with CHF with hyperuricemia in a double-blind, placebo-controlled, randomized crossover study design. Benzbromarone significantly decreased SUA (P<0.01). Brain natriuretic peptide, left ventricular ejection fraction, and dimensions in echocardiographic assessment did not change after benzbromarone therapy. In contrast, fasting insulin (placebo, 18.8+/-8.9 microU/mL; benzbromarone, 11.0+/-6.2 microU/mL; P<0.05), homeostasis model assessment of insulin resistance index (placebo, 5.4+/-2.6; benzbromarone, 3.0+/-1.7; P<0.05), and tumor necrosis factor-alpha (placebo, 2.59+/-0.63 pg/mL; benzbromarone, 2.14+/-0.51 pg/mL; P<0.05) improved after benzbromarone, and the changes in tumor necrosis factor-alpha levels were correlated with reduction of SUA (P<0.05). CONCLUSIONS:These results show that UA lowering without XO inhibition may not have an effect on hemodynamic impairment in CHF pathophysiology. To the extent that these data are correct, this finding suggests that upregulated XO activity rather than UA itself is actively involved in hemodynamic impairment in CHF. Clinical Trial Registration- clinical trials.gov. Identifier: NCT00422318.
Effects of xanthine oxidase inhibition with allopurinol on endothelial function and peripheral blood flow in hyperuricemic patients with chronic heart failure: results from 2 placebo-controlled studies.
Doehner Wolfram,Schoene Nina,Rauchhaus Mathias,Leyva-Leon Francisco,Pavitt Darrell V,Reaveley David A,Schuler Gerhard,Coats Andrew J S,Anker Stefan D,Hambrecht Rainer
BACKGROUND:In patients with chronic heart failure (CHF), hyperuricemia is a common finding and is associated with reduced vasodilator capacity and impaired peripheral blood flow. It has been suggested that the causal link of this association is increased xanthine oxidase (XO)-derived oxygen free radical production and endothelial dysfunction. We therefore studied the effects of XO inhibition with allopurinol on endothelial function and peripheral blood flow in CHF patients after intra-arterial infusion and after oral administration in 2 independent placebo-controlled studies. METHODS AND RESULTS:In 10 CHF patients with normal serum uric acid (UA) levels (315+/-42 micromol/L) and 9 patients with elevated UA (535+/-54 micromol/L), endothelium-dependent (acetylcholine infusion) and endothelium-independent (nitroglycerin infusion) vasodilation of the radial artery was determined. Coinfusion of allopurinol (600 microg/min) improved endothelium-dependent but not endothelium-independent vasodilation in hyperuricemic patients (P<0.05). In a double-blind, crossover design, hyperuricemic CHF patients were randomly allocated to allopurinol 300 mg/d or placebo for 1 week. In 14 patients (UA 558+/-21 micromol/L, range 455 to 743 micromol/L), treatment reduced UA by >120 micromol/L in all patients (mean reduction 217+/-15 micromol/L, P<0.0001). Compared with placebo, allopurinol improved peak blood flow (venous occlusion plethysmography) in arms (+24%, P=0.027) and legs (+23%, P=0.029). Flow-dependent flow improved by 58% in arms (P=0.011). Allantoin, a marker of oxygen free radical generation, decreased by 20% after allopurinol treatment (P<0.001). There was a direct relation between change of UA and improvement of flow-dependent flow after allopurinol treatment (r=0.63, P<0.05). CONCLUSIONS:In hyperuricemic CHF patients, XO inhibition with allopurinol improves peripheral vasodilator capacity and blood flow both locally and systemically.
Association between Serum Uric Acid and Non-Alcoholic Fatty Liver Disease: A Meta-Analysis.
Darmawan Guntur,Hamijoyo Laniyati,Hasan Irsan
Acta medica Indonesiana
BACKGROUND:non-alcoholic fatty liver disease (NAFLD) is known to be associated with some metabolic disorders. Recent studies suggested the role of uric acid in NAFLD through oxidative stress and inflammatory process. This study is aimed to evaluate the association between serum uric acid and NAFLD. METHODS:a systematic literature review was conducted using Pubmed and Cochrane library. The quality of all studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). All data were analyzed using REVIEW MANAGER 5.3. RESULTS:eleven studies from America and Asia involving 100,275 subjects were included. The pooled adjusted OR for NAFLD was 1.92 (95% CI: 1.66-2.23; p<0.00001). Subgroup analyses were done based on study design, gender, non-diabetic subjects, non-obese subjects. All subgroup analyses showed statistically significant adjusted OR and most of which having low to moderate heterogeneity. Two studies revealed relationship between increased serum uric acid levels and severity of NAFLD. No publication bias was observed. CONCLUSION:our study demonstrated association between serum uric acid level and NAFLD. This finding brings a new insight of uric acid in clinical practice. Increased in serum uric acid levels might serve as a trigger for physician to screen for NAFLD.
Effects of uric acid-lowering therapy on the progression of chronic kidney disease: a systematic review and meta-analysis.
Liu Xuemei,Zhai Tingting,Ma Ruixia,Luo Congjuan,Wang Huifang,Liu Liqiu
OBJECTIVES:Whether uric acid levels were associated with the progression of chronic kidney disease (CKD) remained controversial. This meta-analysis was aimed to assess the effect of lowering serum uric acid therapy on the progression of CKD to clarify the role of uric acid in the progression of CKD indirectly. METHODS:Pubmed, Embase, the Cochrane library, CBM were searched for randomized controlled trials (RCTs) that assessed the efficiency of lowering serum uric acid therapy on the progression of CKD without language restriction. Summary estimates of weighted mean differences (WMDs) and relative risk (RR) were obtained by using random-effect or fixed-effect models. Sensitivity analyses were performed to identify the source of heterogeneity. RESULTS:A total of 12 randomized controlled trials with 832 CKD participants were included in the analysis. Pooled estimate for eGFR was in favor of lowering serum uric acid therapy with a mean difference (MD) of 3.88 ml/min/1.73 m, 95% CI 1.26-6.49 ml/min/1.73 m, p = .004 and this was consistent with results for serum creatinine. The risk of worsening of kidney function or ESRD or death was significantly decreased in the treatment group compared to the control group (RR 0.39, 95% CI 0.28-0.52, p< .01). CONCLUSIONS:Uric acid-lowering therapy may be effective in retarding the progression of CKD. Further randomized controlled trials should be performed to confirm the effect of lowering serum uric acid therapy on the progression of CKD.
Serum uric acid and mortality in chronic kidney disease: A systematic review and meta-analysis.
Xia Xi,Luo Qimei,Li Bin,Lin Zhenchuan,Yu Xueqing,Huang Fengxian
Metabolism: clinical and experimental
BACKGROUND:Studies have shown inconsistent results about the association between serum uric acid levels and mortality in patients with chronic kidney disease (CKD). METHODS:A systematic literature search in MEDLINE, Web of Science and bibliographies of retrieved articles was performed to identify studies investigating the association between serum uric acid and mortality in patients with CKD. Pooled hazard ratios (HR) and corresponding 95% confidence intervals (CIs) were calculated using random-effects models. RESULTS:A total of 24 studies with 25,453 patients with CKD were included. By meta-analysis, patients with the highest serum uric acid level were associated with a significantly higher risk for mortality (14 studies; HR, 1.52; 95% CI, 1.33-1.73) compared with patients with the lowest serum uric acid level. For dose-response analysis, a linear relationship (8 studies; Pfor non-linearity=0.14) between serum uric acid levels and risk of mortality was found. Overall, an increase of 1mg/dl in serum uric acid level was associated with an 8% increased risk of mortality (21 studies; HR, 1.08; 95% CI, 1.04-1.11). CONCLUSIONS:Elevated serum uric acid levels are significantly associated with risk of mortality in patients with CKD. Further randomized controlled trials should attempt to determine whether it improves survival to target serum uric acid in patients with CKD.
The role of xanthine oxidoreductase and uric acid in metabolic syndrome.
Battelli Maria Giulia,Bortolotti Massimo,Polito Letizia,Bolognesi Andrea
Biochimica et biophysica acta. Molecular basis of disease
Xanthine oxidoreductase (XOR) could contribute to the pathogenesis of metabolic syndrome through the oxidative stress and the inflammatory response induced by XOR-derived reactive oxygen species and uric acid. Hyperuricemia is strongly linked to hypertension, insulin resistance, obesity and hypertriglyceridemia. The serum level of XOR is correlated to triglyceride/high density lipoprotein cholesterol ratio, fasting glycemia, fasting insulinemia and insulin resistance index. Increased activity of endothelium-linked XOR may promote hypertension. In addition, XOR is implicated in pre-adipocyte differentiation and adipogenesis. XOR and uric acid play a role in cell transformation and proliferation as well as in the progression and metastatic process. Collected evidences confirm the contribution of XOR and uric acid in metabolic syndrome. However, in some circumstances XOR and uric acid may have anti-oxidant protective outcomes. The dual-face role of both XOR and uric acid explains the contradictory results obtained with XOR inhibitors and suggests caution in their therapeutic use.
The physiology of uric acid and the impact of end-stage kidney disease and dialysis.
Murea Mariana,Tucker Bryan M
Seminars in dialysis
Uric acid-mediated biological effects are milieu dependent. In a physiological milieu, serum uric acid serves as an antioxidant; when homeostasis is perturbed, divergent effects are observed depending on the clinical context. Several epidemiologic studies indicated the presence of a direct relationship between higher concentrations of serum uric acid and cardiovascular mortality; yet not all studies support this conclusion. Although high serum levels of uric acid are associated with higher mortality in patients with nondialysis-dependent chronic kidney disease and perhaps in those with end-stage kidney disease receiving peritoneal dialysis, the opposite relationship is seen in patients with end-stage kidney disease on hemodialysis. This review discusses the pathologic mechanisms associated with elevated serum uric acid levels by clinical context; examines the interplay between uric acid metabolism and modality of renal replacement therapy; and presents hypotheses to rationalize the disparate associations between incremental levels of serum uric acid and survival across the continuum of kidney disease and by type of renal replacement therapy.