Allopurinol Initiation and Change in Blood Pressure in Older Adults With Hypertension

Urate-lowering therapy is associated with a reduced risk of arrhythmias: a systematic review and meta-analysis

Objective

While urate-lowering therapy (ULT) is linked to increased cardioprotective benefits on primary prevention of cardiovascular events such myocardial infarction or heart failure, little is known regarding their effects on arrhythmia risk. The purpose of this study was to investigate the relationship between incident arrhythmias and ULT.

Methods

We searched MEDLINE and Embase from inception to May 2023. Included studies were randomized controlled trials and cohort studies that compared the risk of cardiac arrhythmias among ULT users with non-ULT users.

Results

A total of 12,420 patients from five studies were analyzed, comprising 7,359 subjects in the ULT group and 5,061 subjects in the non-ULT group. Our results showed that ULT users had significant reductions in the risk of arrhythmias (pooled relative risk [RR] 0.82, 95% confidence interval [CI] 0.74~0.92, p<0.001, I2=0.0%) compared to non-ULT users. Subgroup analysis did not show that ULT users had a significant reduced risk of atrial fibrillation (pooled RR 0.76, 95% CI 0.54~1.05, p=0.096 with I2=15.4%) compared to non-ULT users.

Conclusion

ULT is associated with lower risk of overall arrhythmias. Further studies are warranted to confirm our findings.

Impact of Hyperuricemia and Urate-Lowering Agents on Cardiovascular Diseases

The association between hyperuricemia and cardiovascular diseases has been studied for many years. Research has shown a link between high uric acid levels and increased risk of including coronary artery disease hypertension and other cardiovascular conditions. Urate-lowering therapy, particularly with xanthine oxidase inhibitors like allopurinol, has shown promising results in reducing blood pressure in individuals with hyperuricemia and hypertension. Clinical trials and studies have demonstrated significant reductions in both systolic and diastolic blood pressure with urate-lowering treatment. Urate-lowering treatment has shown a favorable effect on reducing systolic blood pressure and major adverse cardiovascular events in patients with previous cardiovascular disease. In terms of cardiovascular safety, clinical trials have indicated that xanthine oxidase inhibitors such as febuxostat are non-inferior to allopurinol and do not increase the risk of death or serious adverse events. Overall, these findings highlight the importance of managing hyperuricemia and utilizing urate-lowering therapy to mitigate the adverse cardiovascular effects associated with elevated uric acid levels.

Poor serum uric acid control increases risk for developing hypertension: a retrospective cohort study in China

Background

Serum uric acid (SUA) has been suggested as a contributor of hypertension. However, reports on the relationship between changes in SUA and hypertension are limited. Hence, we aimed to investigate the potential impact of SUA, especially its change over time, on hypertension incidence.

Methods

This dynamic cohort included 6052 participants without hypertension at baseline. Participants were categorized into six grades based on whether baseline SUA was high and whether changes in SUA progressed to hyperuricemia or decreased to normal levels. Grades 1 to 6 represented the participants' SUA control from best to worst. Logistic regression and restricted cubic spline (RCS) models were used to explore the association of the grades of SUA control and hypertension incidence.

Results

During a median follow-up of 6 years, 2550 (42.1%) participants developed hypertension. After adjusting confounding factors, compared to grade 1 with the best control of SUA, the odds ratios for grades 2 to 6 with worse control were 1.347 (1.109-1.636), 1.138 (0.764-1.693), 1.552 (1.245-1.934), 1.765 (1.170-2.663), and 2.165 (1.566-2.993), respectively. RCS indicated a linear correlation between the risk of hypertension and changes in SUA, and an elevated risk in participants with baseline hyperuricemia. Subgroup analyses showed that grades of SUA control had an interaction with systolic (P = 0.003) and diastolic blood pressure (P < 0.001). Sensitivity analyses further determined the robustness of the result that participants with poor SUA control have a higher risk of developing hypertension.

Conclusion

Poor SUA control, an increase in SUA over time, rises the risk of developing hypertension regardless of whether the initial SUA is normal or not. Initial hyperuricemia will exacerbate this risk. Effective SUA control should be an important measure for primary prevention of hypertension.

Sodium-Glucose Cotransporter 2 Inhibitors to Decrease the Uric Acid Concentration-A Novel Mechanism of Action

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) are glucose-lowering agents whose positive impact on cardiovascular risk has been described extensively. Not only do they influence lipid profile, blood pressure, atherosclerosis risk, hemoglobin level, and insulin resistance, but they also reduce cardiovascular events, all-cause mortality, and hospitalization rates. Some of these effects may be due to their impact on serum uric acid (SUA) concentration. Findings from nine meta-analyses showed that, indeed, SGLT2is significantly reduce SUA. The data on the drug- and dose-dependency of this effect were inconclusive. Several factors alternating the beneficial effects of SGLT2is on SUA, such as glycated hemoglobin concentration (HbA1c), presence of diabetes, and baseline SUA level, were described. Even though there is a consensus that the lowering of SUA by SGLT2is might be due to the increased urinary excretion rate of uric acid (UEUA) rather than its altered metabolism, the exact mechanism remains unknown. The influence of SGLT2is on SUA may not only be used in gout treatment but may also be of huge importance in explaining the observed pleiotropic effects of SGLT2is.

Uric Acid and Hypertension: a Review of Evidence and Future Perspectives for the Management of Cardiovascular Risk

Uric acid is the final product of purine metabolism, and its increased serum levels have been directly involved in the pathogenesis and natural history of hypertension. The relationship between elevated uric acid and hypertension has been proven in both animals and humans, and its relevance is already evident in childhood and adolescent population. The mechanism responsible for blood pressure increase in hyperuricemic subjects is implicating both oxidative stress and intracellular urate activity with a primary involvement of XOR (xanthine-oxidoreductase activity). An increase in the relative risk of hypertension has been confirmed by genetic data and by large meta-analyses of epidemiological data. The effects of urate-lowering treatment on blood pressure control in patients with elevated serum uric acid has been investigated in a small number of reliable studies with a large heterogeneity of patient populations and study designs. However, 2 large meta-analyses suggest a significant effect of urate-lowering treatment on blood pressure, thus confirming the significant relationship between high serum urate and blood pressure. The future research should be focused on a more appropriate identification of patients with cardiovascular hyperuricemia by considering the correct cardiovascular threshold of serum urate, the time-course of uricemia fluctuations, and the identification of reliable markers of urate overproduction that could significantly clarify the clinical and therapeutic implications of the interaction between serum uric acid and hypertension.

Elevated Serum Uric Acid and Cardiovascular Disease: A Review and Potential Therapeutic Interventions

Several landmark studies found a relationship between elevated serum uric acid (SUA) levels and cardiovascular disease (CVD). In fact, the association between hyperuricemia and hypertension (HTN), coronary artery disease (CAD), and heart failure (HF) is currently well-established. While the mechanism linking hyperuricemia and CVD is not fully known, a systemic inflammatory response by the host is believed to play a role. With the goal of decreasing the morbidity and mortality of CVD in patients with hyperuricemia, the focus has now turned to properly optimizing a medication regimen for this patient population. Recent studies have shown that controlling underlying inflammation can, in fact, lead to better cardiovascular outcomes for populations with acute and chronic coronary disease. In this paper, we will discuss the current state of understanding on the association of hyperuricemia and cardiovascular disease. Furthermore, we will look into the most recent clinical trials showing the effects anti-inflammatory medications have on both decreasing and recovering from cardiovascular events. We will conclude with a discussion on, given the information mentioned above, how to properly optimize a medication regimen in patients with elevated SUA levels with a focus on decreasing the morbidity and mortality associated with CVD.

Febuxostat ameliorates high salt intake-induced hypertension and renal damage in Dahl salt-sensitive rats

OBJECTIVE

Several clinical studies have reported that xanthine oxidoreductase inhibitors have antihypertensive and renal protective effects but their mechanisms have not been fully determined. This study aims to clarify these mechanisms by examining the effects of febuxostat, which is a novel selective xanthine oxidoreductase inhibitor, in Dahl salt-sensitive rats.

METHODS

Eight-week-old male Dahl salt-sensitive rats were fed a normal salt (0.6% NaCl) or high salt (8% NaCl) diet for 8 weeks. A portion of the rats that were fed high salt diet were treated with febuxostat (3 mg/kg per day) simultaneously. Additionally, acute effects of febuxostat (3 mg/kg per day) were examined after high salt diet feeding for 4 or 8 weeks.

RESULTS

Treatment with febuxostat for 8 weeks attenuated high salt diet-induced hypertension, renal dysfunction, glomerular injury, and renal interstitial fibrosis. Febuxostat treatment reduced urinary excretion of H2O2 and malondialdehyde and renal thiobarbituric acid reactive substances content. High salt diet increased xanthine oxidoreductase activity and expression in the proximal tubules and medullary interstitium. Febuxostat completely inhibited xanthine oxidoreductase activity and attenuated the high salt diet-increased xanthine oxidoreductase expression. Febuxostat transiently increased urine volume and Na+ excretion without change in blood pressure or urinary creatinine excretion after high salt diet feeding for 4 or 8 weeks.

CONCLUSION

Febuxostat ameliorates high salt diet-induced hypertension and renal damage with a reduction of renal oxidative stress in Dahl salt-sensitive rats. The antihypertensive effect of febuxostat may be mediated in part by diuretic and natriuretic action.

Pathophysiological Mechanisms of Hypertension Development Induced by Fructose Consumption

During the past several decades, there has been a dramatic increase in fructose consumption worldwide in parallel with epidemics of metabolic diseases. Accumulating evidence has suggested that excessive fructose consumption...

The Role of Uric Acid in Acute and Chronic Coronary Syndromes

Uric acid (UA) is the final product of the catabolism of endogenous and exogenous purine nucleotides. While its association with articular gout and kidney disease has been known for a long time, new data have demonstrated that UA is also related to cardiovascular (CV) diseases. UA has been identified as a significant determinant of many different outcomes, such as all-cause and CV mortality, and also of CV events (mainly Acute Coronary Syndromes (ACS) and even strokes). Furthermore, UA has been related to the development of Heart Failure, and to a higher mortality in decompensated patients, as well as to the onset of atrial fibrillation. After a brief introduction on the general role of UA in CV disorders, this review will be focused on UA's relationship with CV outcomes, as well as on the specific features of patients with ACS and Chronic Coronary Syndrome. Finally, two issues which remain open will be discussed: the first is about the identification of a CV UA cut-off value, while the second concerns the possibility that the pharmacological reduction of UA is able to lower the incidence of CV events.

A Non-purine Xanthine Oxidoreductase Inhibitor Reduces Albuminuria in Patients with DKD: A Randomized Controlled Trial

Background

Diabetic kidney disease (DKD) is characterized by albuminuria and reduced renal function. Whether xanthine oxidoreductase inhibitors (XORIs) have a renoprotective effect in DKD patients with type 2 diabetes remains controversial. We conducted a proof-of-concept study to investigate the renal effects of a novel XORI, TMX-049, in patients with DKD and type 2 diabetes.

Methods

This is a multicenter, 12-week, randomized, double-blind, placebo-controlled phase 2a trial conducted at 49 centers across the United States between April 2018 and June 2019. In total, 130 patients with type 2 diabetes, urine albumin-creatinine ratio (UACR) 200 - 3000 mg/g, eGFR ≥30 ml/min per 1.73 m2, and serum uric acid (sUA) 4 - 10 mg/dl were randomized 1:1:1 to TMX-049 200 mg (n=44) or 40 mg (n=44), or placebo (n=42). The primary end point was change in log-transformed UACR at week 12 from baseline. The secondary end points included changes in UACR, eGFR, and sUA from baseline.

Results

The least squares mean differences for changes in log-transformed UACR from baseline to week 12 compared with placebo were -0.43 (95% confidence interval [95% CI], -0.82 to -0.04, P=0.03) for TMX-049 200 mg and -0.05 (95% CI, -0.44 to 0.34, P=0.80) for 40 mg; a 35% reduction in UACR was observed with TMX-049 200 mg (ratio versus placebo, 0.65; 95% CI, 0.44 to 0.96) but not 40 mg (0.95; 95% CI, 0.64 to 1.41). Throughout the treatment period, marked reductions in sUA levels but no changes in eGFR were observed with both TMX-049 doses. TMX-049 was generally well tolerated, although two patients with TMX-049 200 mg developed gout.

Conclusions

TMX-049 200 mg reduced albuminuria at 12 weeks in patients with DKD and type 2 diabetes. TMX-049 may exert a renoprotective effect independent of its sUA-lowering effect.

The association between urate-lowering therapies and treatment-related adverse events, liver damage, and major adverse cardiovascular events (MACE): A network meta-analysis of randomized trials

PURPOSE

Hyperuricemia is a common disease that may lead to gout, renal damage, and cardiovascular events. Oral medication is the main treatment for hyperuricemia patients when lifestyle intervention fails. An evaluation of the safety of various urate-lowering therapies (ULTs) is integral to clinical decision-making. We constructed a network meta-analysis (NMA) to evaluate the safety of oral ULTs.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched up to April 1, 2021, for randomized controlled trials that examined the safety of ULTs. The language restriction was English. The three outcomes used to assess the safety of uric acid lowering medications were treatment-related adverse events, liver damage, and major adverse cardiovascular events (MACE).

RESULTS

Thirty-two trials enrolling 23,868 individuals were included in the study. In terms of treatment-related adverse events, there were no statistically significant differences between five uric acid lowering medications and placebo: allopurinol (risk ratio (RR): 1.08; 95% credible interval (CrI): 0.91, 1.29), febuxostat (RR: 1.05; 95% CrI: 0.89, 1.25), lesinurad (RR: 1.19; 95% CrI: 0.85, 1.67), lesinurad combined with xanthine oxidase inhibitor (XOI, RR: 1.05; 95% CrI: 0.83, 1.32), and topiroxostat (RR: 1.01; 95% CrI: 0.83, 1.23). Topiroxostat likely increases risk of liver damage (RR: 2.65; 95%CI: 1.24, 5.70; NNH: 33.40) as compared with placebo. With regard to MACE, there were no statistically significant differences between three uric acid lowering medications and placebo: allopurinol (RR: 0.63; 95% CrI: 0.36, 1.34), febuxostat (RR: 0.69; 95% CrI: 0.38, 1.66), and lesinurad combined with XOI (RR: 0.56; 95% CrI: 0.23, 1.85). The rankings of different interventions were depicted by cumulative ranking curve (SUCRA).

CONCLUSIONS

Through NMA, we provide some evidence for the safety of ULTs. We found no statistically significant differences in their effects on treatment-related adverse events and MACE. However, topiroxostat likely increases the risk of liver damage.

Effects of intensive urate lowering therapy with febuxostat in comparison with allopurinol on pulse wave velocity in patients with gout and increased cardiovascular risk: the FORWARD study

AIMS

Hyperuricaemia and gout are strongly related with traditional cardiovascular risk factors and vascular damage. This study aimed to assess whether febuxostat and allopurinol could differently influence carotid-femoral pulse wave velocity (cfPWV) in patients with gout and elevated serum uric acid (SUA) levels.

METHODS AND RESULTS

A multi-centre, multinational, phase IV, randomized, parallel-group, active-controlled, open label trial with blind end-points evaluation. One hundred and ninetyseven adults with gout and SUA levels ≥8 mg/dL were randomised to febuxostat or allopurinol in a 1:1 ratio for 36 weeks. The primary outcome was the comparison of the effects of febuxostat and allopurinol on changes in cfPWV. The mean cfPWV values at randomisation and week 36 were respectively 8.69 m/s and 9.00 m/s for subjects randomised to febuxostat and 9.02 m/s and 9.05 m/s for subjects randomised to allopurinol. No statistically significant changes in cfPWV by treatment assignment were observed at any time point for any of the assessed parameters. More subjects who received febuxostat had serum urate concentrations ≤6 mg/dL following treatment (78.3% vs 61.1% at week 36, p = 0.0137). Treatment-emergent adverse events were reported by 51 (52.0%) patients randomised to febuxostat and 63 (62.5%) patients randomised to allopurinol. The majority of events were mild in both treatment groups and included gout flares and arthralgia.

CONCLUSIONS

In patients with gout and elevated SUA levels the arterial stiffness remained stable both with febuxostat and allopurinol. Febuxostat was more effective and faster than allopurinol in achieving the SUA target. Both treatments were safe and well tolerated.

Hyperuricaemia and gout in cardiovascular, metabolic and kidney disease

During the last century, there has been an increasing prevalence of hyperuricaemia noted in many populations. While uric acid is usually discussed in the context of gout, hyperuricaemia is also associated with hypertension, chronic kidney disease, hypertriglyceridaemia, obesity, atherosclerotic heart disease, metabolic syndrome, and type 2 diabetes. Here we review the connection between hyperuricaemia and cardiovascular, kidney and metabolic diseases. Contrary to the popular view that uric acid is an inert metabolite of purine metabolism, recent studies suggest serum uric acid may have a variety of pro-inflammatory, pro-oxidative and vasoconstrictive actions that may contribute to cardiometabolic diseases. Hyperuricaemia is a predictive factor for the development of hypertension, metabolic syndrome, type 2 diabetes, coronary artery disease, left ventricular hypertrophy, atrial fibrillation, myocardial infarction, stroke, heart failure and chronic kidney disease. Treatment with uric acid-lowering therapies has also been found to improve outcomes in patients with hypertension and kidney disease, in some but not all studies. In conclusion, uric acid is emerging as a potentially treatable risk factor for cardiometabolic diseases, and more clinical trials investigating the potential benefit of lowering serum uric acid are recommended in individuals with hyperuricaemia with and without deposition and concomitant hypertension, metabolic syndrome or chronic kidney disease.

Hyperuricemia and Risk of Cardiovascular Outcomes: The Experience of the URRAH (Uric Acid Right for Heart Health) Project

The latest European Guidelines of Arterial Hypertension have officially introduced uric acid evaluation among the cardiovascular risk factors that should be evaluated in order to stratify patient's risk. In fact, it has been extensively evaluated and demonstrated to be an independent predictor not only of all-cause and cardiovascular mortality, but also of myocardial infraction, stroke and heart failure. Despite the large number of studies on this topic, an important open question that still need to be answered is the identification of a cardiovascular uric acid cut-off value. The actual hyperuricemia cut-off (> 6 mg/dL in women and 7 mg/dL in men) is principally based on the saturation point of uric acid but previous evidence suggests that the negative impact of cardiovascular system could occur also at lower levels. In this context, the Working Group on uric acid and CV risk of the Italian Society of Hypertension has designed the Uric acid Right for heArt Health project. The primary objective of this project is to define the level of uricemia above which the independent risk of CV disease may increase in a significantly manner. In this review we will summarize the first results obtained and describe the further planned analysis.

Management of asymptomatic hyperuricemia: Integrated Diabetes & Endocrine Academy (IDEA) consensus statement

AIM

The definition and management of asymptomatic hyperuricemia has been an area of controversy for many decades. Debate persists regarding the benefit of treating all cases of asymptomatic hyperuricemia and hence, unsurprisingly there are no clear clinical practice guidelines from our country.

PARTICIPANTS

Ten members consisting of eminent physicians, endocrinologists, nephrologist and a rheumatologist were selected by the Integrated Diabetes & Endocrine Academy (IDEA) for a closed meeting with the aim to come to a consensus.

EVIDENCE

A literature search was performed using PubMed and Cochrane library following which published articles in indexed peer review journals were selected.

CONSENSUS PROCESS

Each participant voiced their opinion after reviewing the available data and a consensus was reached after three meetings by voting.

CONCLUSION

Recommendations were made on important areas such as definition, investigation and management of asymptomatic hyperuricemia.

Hyperuricemia and Cardiovascular Disease

Purine metabolism in the circulatory system yields uric acid as its final oxidation product, which is believed to be linked to the development of gout and kidney stones. Hyperuricemia is closely correlated with cardiovascular disease, metabolic syndrome, and chronic kidney disease, as attested by the epidemiological and empirical research. In this review, we summarize the recent knowledge about hyperuricemia, with a special focus on its physiology, epidemiology, and correlation with cardiovascular disease. This review also discusses the possible positive effects of treatment to reduce urate levels in patients with cardiovascular disease and hyperuricemia, which may lead to an improved clinical treatment plan.

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.

Uric acid and the cardio-renal effects of SGLT2 inhibitors

Sodium/glucose co-transporter-2 (SGLT2) inhibitors, which lower blood glucose by increasing renal glucose elimination, have been shown to reduce the risk of adverse cardiovascular (CV) and renal events in type 2 diabetes. This has been ascribed, in part, to haemodynamic changes, body weight reduction and several possible effects on myocardial, endothelial and tubulo-glomerular functions, as well as to reduced glucotoxicity. This review evaluates evidence that an effect of SGLT2 inhibitors to lower uric acid may also contribute to reduced cardio-renal risk. Chronically elevated circulating uric acid concentrations are associated with increased risk of hypertension, CV disease and chronic kidney disease (CKD). The extent to which uric acid contributes to these conditions, either as a cause or an aggravating factor, remains unclear, but interventions that reduce urate production or increase urate excretion in hyperuricaemic patients have consistently improved cardio-renal prognoses. Uric acid concentrations are often elevated in type 2 diabetes, contributing to the "metabolic syndrome" of CV risk. Treating type 2 diabetes with an SGLT2 inhibitor increases uric acid excretion, reduces circulating uric acid and improves parameters of CV and renal function. This raises the possibility that the lowering of uric acid by SGLT2 inhibition may assist in reducing adverse CV events and slowing progression of CKD in type 2 diabetes. SGLT2 inhibition might also be useful in the treatment of gout and gouty arthritis, especially when co-existent with diabetes.

Uric Acid Is a Strong Risk Marker for Developing Hypertension From Prehypertension: A 5-Year Japanese Cohort Study

Prehypertension frequently progresses to hypertension, a condition associated with high morbidity and mortality from cardiovascular diseases and stroke. However, the risk factors for developing hypertension from prehypertension remain poorly understood. We conducted a retrospective cohort study using the data from 3584 prehypertensive Japanese adults (52.1±11.0 years, 2081 men) found to be prehypertensive in 2004 and reexamined in 2009. We calculated the cumulative incidences of hypertension over 5 years, examined risk factors, and calculated odds ratios (ORs) for developing hypertension after adjustments for age, sex, body mass index, smoking and drinking habits, baseline systolic and diastolic blood pressure, pulse rate, diabetes mellitus, dyslipidemia, chronic kidney disease, and serum uric acid levels. The additional analysis evaluated whether serum uric acid (hyperuricemia) constituted an independent risk factor for developing hypertension. The cumulative incidence of hypertension from prehypertension over 5 years was 25.3%. There were no significant differences between women and men (24.4% versus 26.0%; P=0.28). The cumulative incidence of hypertension in subjects with hyperuricemia (n=726) was significantly higher than those without hyperuricemia (n=2858; 30.7% versus 24.0%; P<0.001). After multivariable adjustments, the risk factors for developing hypertension from prehypertension were age (OR, 1.023; P<0.001), female sex (OR, 1.595; P<0.001), higher body mass index (OR, 1.051; P<0.001), higher baseline systolic (OR, 1.072; P<0.001) and diastolic blood pressure (OR, 1.085; P<0.001), and higher serum uric acid (OR, 1.149; P<0.001). Increased serum uric acid is a strong risk marker for developing hypertension from prehypertension. Further studies are needed to determine whether treatment of hyperuricemia in prehypertensive subjects could impede the onset of hypertension.

The Effect of Xanthine Oxidase Inhibitors on Blood Pressure and Renal Function

Several epidemiological studies have demonstrated the existence of a correlation between high serum uric acid (SUA) levels, hypertension, and chronic kidney disease (CKD). Xantine oxidase inhibitors (XOI) are the most powerful uric acid lowering drugs, with presumed beneficial effects on cardiovascular and renal system. The multifactorial mechanism linking hyperuricemia with cardiovascular and renal diseases involves both the SUA level and the xanthine oxidase (XO) activity. In this context, the clinical research has been recently focused at assessing the efficacy of urate-lowering drugs active on XO in patients with abnormal blood pressure values and renal dysfunction. The mechanism of action responsible for the beneficial effect of XOI has not completely elucidated, and long-term studies involving large population samples are needed. In particular, XOI could play an important role in the management of hypertension and CKD, especially in patients not entirely controlled by conventional therapies. In the present review, we summarize the results of recent clinical trials that largely support a positive effect of allopurinol and febuxostat on blood pressure, glomerular filtration rate (GFR), and serum creatinine in different populations of patients. Will these drugs be considered a reliable choice or alternative to currently used drugs for the hypertension and kidney failure treatment? The debate is open, but much evidence is accumulating and supporting this role.

Asymptomatic hyperuricemia: is it time to intervene?

Whether to treat hyperuricemia uncomplicated by articular gout, urolithiasis, or uric acid nephropathy is an exercise in clinical judgment and universal agreement is lacking. Patients with coronary artery disease, chronic kidney disease, and early onset hypertension with persistent hyperuricemia are likely to be benefited with urate-lowering therapy. The paradigm of the causative association of hyperuricemia with cardiovascular and chronic kidney diseases seems to have progressed from skepticism to increasing evidence of a true relationship. Although such evidences are mounting, they are not enough to support pharmacotherapy for all patients with asymptomatic hyperuricemia. Further studies are needed to determine which patients are likely to get beneficial effects from pharmacotherapy and the minimum threshold of uric acid level required to experience clinical benefits.

The Future Challenge of Reactive Oxygen Species (ROS) in Hypertension: From Bench to Bed Side

Reactive oxygen species (ROS) act as signaling molecules that control physiological processes, including cell adaptation to stress. Redox signaling via ROS has quite recently become the focus of much attention in numerous pathological contexts, including neurodegenerative diseases, kidney and cardiovascular disease. Imbalance in ROS formation and degradation has also been implicated in essential hypertension. Essential hypertension is characterized by multiple genetic and environmental factors which do not completely explain its associated risk factors. Thereby, even if advances in therapy have led to a significant reduction in hypertension-associated complications, to interfere with the unbalance of redox signals might represent an additional therapeutic challenge. The decrease of nitric oxide (NO) levels, the antioxidant activity commonly found in preclinical models of hypertension and the ability of antioxidant approaches to reduce ROS levels have spurred clinicians to investigate the contribution of ROS in humans. Indeed, particular effort has recently been devoted to understanding how redox signaling may contribute to vascular pathobiology in human hypertension. However, although biomarkers of oxidative stress have been found to positively correlate with blood pressure in preclinical model of hypertension, human data are less convincing. We herein provide an overview of the most relevant mechanisms via which oxidative stress might contribute to the pathophysiology of essential hypertension. Moreover, alternative approaches, which are directed towards improving antioxidant machinery and/or interfering with ROS production, are also discussed.

[Independent risk factors for severe cardiovascular events in male patients with gout: Results of a 7-year prospective study]

AIM

To determine risk factors for severe cardiovascular (CV) events (CVEs) in male patients with crystal-verified gout.

SUBJECTS AND METHODS

251 male patients with crystal-verified gout were prospectively followed up in 2003 to 2013. The mean follow-up period was 6.9±2.0 years. New severe CVE cases and deaths were recorded. Logistic regression was used to analyze the impact of traditional and other risk factors and allopurinol use on the risk for severe CVEs.

RESULTS

32 patients died during the follow-up period. Severe CVEs were recorded in 58 (23.1%) patients; CVE deaths were notified in 22 (8.8%) patients. The risk of all severe CVEs was high for hypertension, increased serum high-sensitivity C-reactive protein (hs-CRP) level (>5 mg/l), ≥ stage III chronic kidney disease (CKD) (glomerular filtration rate, <60 ml/min/1.73 m2), alcohol intake (>20 g/day), coronary heart disease (CHD), and a family history of premature CHD. The risk of fatal CVEs was highest for elevated serum hs-CRP level, ≥ stage III CKD, a family history of premature CHD, hypercholesterolemia, upper quartile of serum uric acid levels (>552 µmol/l), and regular intake of allopurinol.

CONCLUSION

In addition to the traditional risk factors of CV catastrophes, the presence of chronic inflammation and the impact of high serum uric acid levels may explain the high frequency of CV catastrophes.

Allopurinol and the risk of ventricular arrhythmias in the elderly: a study using US Medicare data

BACKGROUND

There are no published human studies investigating whether the use of allopurinol, the most commonly used medication for the treatment of hyperuricemia in gout, the most common type of inflammatory arthritis in adults, has any beneficial effects on ventricular electrophysiology. The objective of our study was to assess whether allopurinol use is associated with a reduction in the risk of ventricular arrhythmias (VA).

METHODS

We used the 5% random sample of Medicare beneficiaries from 2006-2012 to examine new allopurinol use and the risk of incident VA. Multivariable Cox regression analyses were adjusted for demographics (age, race, sex), comorbidity, cardiac medications, and conditions associated with VA. We calculated hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Of the 28,755 episodes of new allopurinol use, 2538 were associated with incident VA (8.8%). Among patients with incident VA, 54% were male, 78% were White, 75% had gout as the underlying diagnosis, and the mean Charlson-Romano comorbidity score was 4.8. The crude incidence of VA per 1,000,000 person-days declined as the duration of allopurinol use increased: 1-180 days, 151; 181 days to 2 years, 105; and > 2 years, 85. In multivariable-adjusted analyses, compared to non-use, allopurinol use was associated with lower HR of VA of 0.82 (95% CI, 0.76-0.90). Compared to allopurinol non-use, longer allopurinol use durations were significantly associated with lower multivariable-adjusted HR for VA: 1-180 days, 0.96 (95% CI, 0.85-1.08); 181 days to 2 years, 0.76 (95% CI, 0.68-0.85); and > 2 years, 0.72 (95% CI, 0.60-0.87). Multiple sensitivity analyses adjusting for cardiac conditions, anti-arrhythmic drugs and alternate definitions confirmed our findings with minimal/no attenuation of estimates.

CONCLUSION

Allopurinol use and use duration of more than 6 months were independently associated with a lower risk of VA. Future studies need to assess the pathophysiology of this potential benefit.

Effect of uric acid-lowering therapy on blood pressure: systematic review and meta-analysis

BACKGROUND

The purpose of this meta-analysis was to determine if uric acid-lowering therapy is associated with a decrease in blood pressure (BP) and serum creatinine levels.

MATERIALS AND METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until 29 June 2016, with keywords: uric-acid-lowering therapy, allopurinol, febuxostat, uricosuric, and BP. Only randomized controlled trials were included. The primary outcomes were reduction in systolic BP (SBP) and diastolic BP (DBP), and secondary was reduction in serum creatinine level.

RESULTS

Patients treated with allopurinol had greater reduction in SBP (standardized difference in means [SDM] = 0.321, 95% confidence interval [CI]: 0.145-0.497, p < 0.001), DBP (SDM = 0.260, 95% CI: 0.102 to 0.417, p = 0.001), and creatinine level (SDM = 0.312, 95% CI: 0.008 to 0.615, p = 0.044) than control patients. Subgroup analysis showed that allopurinol significantly decreased SBP whether or not antihypertensive drugs were being administered; a decrease in DBP was only seen in patients receiving antihypertensive drugs. Low-dose allopurinol (≤300 mg/day) was more effective at reducing SBP than high-dose (>300 mg/day) in patients receiving antihypertensive drugs.

CONCLUSIONS

These results support that allopurinol decreases BP and creatinine levels in patients with hyperuricemia. KEY MESSAGES Allopurinol decreases SBP and DPB, and creatinine levels in patients with hyperuricemia. Allopurinol resulted in a significant decrease in SBP in patients with or without treatment of antihypertensive drugs. A dose of allopurinol of ≤300 mg per day might be more effective than a higher dose.

An evidence-based review on urate-lowering treatments: implications for optimal treatment of chronic hyperuricemia

Several studies suggest that chronic hyperuricemia, the main precursor of gout, is involved in the pathogenesis of different systemic disorders that affect cardiovascular and renal systems, such as hypertension, obesity, hypercholesterolemia, atherosclerosis, metabolic syndrome, chronic heart failure, and chronic kidney disease. Recent epidemiological evidence has shown an increasing trend in the prevalence of hyperuricemia and gout in the Western world: a number of population-based studies estimate a prevalence of up to 21% for hyperuricemia and 1%–4% for gout. As such, early detection and careful management of this pathological condition is required, starting from lifestyle changes (mainly based on a diet low in red meat, sugars, and alcoholic beverages, with increased intake of vegetables, water, and vitamin C sources), adding specific drugs to lead serum uric acid (SUA) levels under the target value of 7 mg/dL. In particular, nonselective and selective XO inhibitors (allopurinol, oxypurinol, febuxostat) reduce SUA levels and the overproduction of reactive oxygen species, mainly related to XO overactivity that often causes inflammatory damage to the vascular endothelium. The effect of lowering SUA levels via XO inhibition includes an attenuation of oxidative stress and related endothelial dysfunction that largely contribute to the pathophysiology of metabolic syndrome and cardiovascular diseases. Therefore, the inhibition of XO overactivation seems to be an excellent therapeutic option to limit the harmful effects of excess UA and reactive oxygen species. In conclusion, rapid diagnosis and correct therapy for hyperuricemia may also improve the prevention and/or treatment of serious and multifactorial diseases. The available evidence supports the importance of promoting new experimental clinical trials to confirm the emerging antioxidant role of XO inhibitors, which could effectively contribute to cardiovascular and chronic kidney disease prevention.

Baseline and Change in Uric Acid Concentration Over Time Are Associated With Incident Hypertension in Large Korean Cohort

BACKGROUND

It is uncertain whether high-baseline uric acid (UA) or change in UA concentration over time is related to development of incident hypertension. To investigate relationships between: (i) baseline serum UA concentration and (ii) change in UA concentration and incident hypertension.

METHODS

About 96,606 Korean individuals (with follow-up UA data available for 56,085 people) participating in a health check program was undertaken. Cox regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incident hypertension according to UA quartiles regarding the lowest UA quartile as the reference, and also according to change in UA concentration comparing individuals with an increase in UA to those with a decrease in UA concentration over time.

RESULTS

Total follow up time was 8 years (median follow-up 3.3 years; interquartile range, 1.9-5.1). About 10,405 cases of incident hypertension occurred. In the fully adjusted regression models, the HRs (95% CI) for incident hypertension comparing the highest vs. the lowest quartiles of UA were 1.29 (1.19-1.38) in men and 1.24 (1.09-1.42) in women, with statistically significant P for trend for both gender. Additionally, stable or increasing UA concentration over time was associated with increased risk of incident hypertension, particularly in participants with baseline UA concentration ≥median (aHRs 1.14; 95% CI (1.03-1.26) and 1.18; 95% CI (0.98-1.40) in men and women, respectively).

CONCLUSIONS

High initial UA concentration and increases in UA concentration over time should be considered independent risk factors for hypertension.

Activation of Renal (Pro)Renin Receptor Contributes to High Fructose-Induced Salt Sensitivity

A high-fructose diet is shown to induce salt-sensitive hypertension, but the underlying mechanism largely remains unknown. The major goal of the present study was to test the role of renal (pro)renin receptor (PRR) in this model. In Sprague-Dawley rats, high-fructose intake increased renal expression of full-length PRR, which were attenuated by allopurinol. High-fructose intake also upregulated renal mRNA and protein expression of sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter, as well as in vivo Na/K/2Cl cotransporter activity, all of which were nearly completely blocked by a PRR decoy inhibitor PRO20 or allopurinol treatment. Parallel changes were observed for indices of intrarenal renin-angiotensin-system including renal and urinary renin and angiotensin II levels. Radiotelemetry demonstrated that high-fructose or a high-salt diet alone did not affect mean arterial pressure, but the combination of the 2 maneuvers induced a ≈10-mm Hg increase of mean arterial pressure, which was blunted by PRO20 or allopurinol treatment. In cultured human kidney 2 cells, both fructose and uric acid increased protein expression of soluble PRR in a time- and dose-dependent manner; fructose-induced PRR upregulation was inhibited by allopurinol. Taken together, our data suggest that fructose via uric acid stimulates renal expression of PRR/soluble PRR that stimulate sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter expression and intrarenal renin-angiotensin system to induce salt-sensitive hypertension.

Changes in selected metabolic parameters in patients over 65 receiving hydrochlorothiazide plus amiloride, atenolol or placebo in the MRC elderly trial

Background

Treatment of hypertension reduces incidence of stroke, myocardial infarction and heart failure perhaps partly by controlling different metabolic parameters. There is limited information regarding the changes in potassium, sodium, weight, cholesterol and glucose levels in patients using anti-hypertensives. This study aimed to determine changes in potassium, sodium, glucose, cholesterol, weight, urea and urate levels in patients using anti-hypertensives. Furthermore, to describe these changes and differences between the atenolol, hydrochlorothiazide plus amiloride and placebo arms of the Medical Research Council (MRC) elderly randomised controlled trial.

Methods

Patients were randomly allocated to one of the three treatment arms. Measurements were taken at baseline, end of year one and end of year two in 4396 subjects. Linear Mixed Models (LMM) were used to determine the longitudinal profiles of sodium, potassium, weight, cholesterol, glucose, urea and urate. Estimates of changes within groups and difference between groups were obtained.

Results

Patients randomised to receive hydrochlorothiazide + amiloride experienced a significantly greater mean reduction in potassium, sodium and weight compared to placebo at end of year one - mean differences in change −0.18 mmol/L, (95 % CI: −0.21, −0.15); −1.45 mmol/L, (95 % CI: −1.62, −1.29) and −0.46 kgs (95 % CI: −0.73, −0.20) respectively, and greater increases in cholesterol, urea and urate - mean differences in change 0.16 mmol/L, (95 % CI: 0.10,0.22); 0.77 mmol/L, (95 % CI: 0.68, 0.87) and 53.10 μmol/L, (95 % CI: 49.35, 56.85) respectively. Changes were in the same direction but smaller in the atenololarm except for potassium and weight (increases). No group differences in glucose were found.

Conclusion

Results were in line with expectation except for lack of change in glucose in the hydrochlorothiazide + amiloride arms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0368-2) contains supplementary material, which is available to authorized users.

Allopurinol reduces the risk of myocardial infarction (MI) in the elderly: a study of Medicare claims

BACKGROUND

Previous observational studies that have examined the association of allopurinol with myocardial infarction (MI) have provided contradictory results. One study showed that allopurinol reduced the risk, while another study showed an increased risk with allopurinol. Therefore, our objective was to assess whether allopurinol use is associated with a reduction in the risk of MI in the elderly.

METHOD

We used the 2006-2012 5 % random sample of Medicare beneficiaries to study the association of new allopurinol initiation and the risk of incident MI in a cohort study. Multivariable-adjusted Cox regression models adjusted for age, gender, race, and Charlson index, in addition to various cardio-protective medications (beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, diuretics, statins). We calculated hazard ratios (HRs) with 95 % confidence intervals (CIs). Sensitivity analyses adjusted for coronary artery disease (CAD) risk factors, including hypertension, hyperlipidemia, diabetes, and smoking.

RESULTS

Of the 29,298 episodes of incident allopurinol use, 1544 were associated with incident MI (5.3 % episodes). Allopurinol use was associated with reduced hazards of MI, with a HR of 0.85 (95 % CI, 0.77 to 0.95). Compared to no allopurinol use, longer durations of allopurinol use were associated with a lower HR of MI: 1-180 days, 0.98 (95 % CI, 0.84 to 1.14); 181 days to 2 years, 0.83 (95 % CI, 0.72 to 0.95); and >2 years, 0.70 (95 % CI, 0.56 to 0.88). Other factors associated with a higher hazard of MI were: age 75 to <85 years and ≥85 years, male gender, higher Charlson index score, and the use of an ACE inhibitor. Adjustment for CAD risk factors confirmed these findings.

CONCLUSION

Incident allopurinol use was associated with a reduction in the risk of incident MI in the elderly. Longer durations of allopurinol use reduced the risk of incident MI incrementally. Future studies should assess the underlying mechanisms for MI prevention and assess the risk-benefit ratio for allopurinol use.

Allopurinol and the risk of atrial fibrillation in the elderly: a study using Medicare data

OBJECTIVE

To assess the effect of allopurinol use on the risk of incident atrial fibrillation (AF) in the elderly.

METHODS

We used the 5% random Medicare Claims data from 2006 to 2012 to examine the association of allopurinol use and incident AF in a cohort of patients with an absence of AF at baseline (at least 365 days). Multivariable-adjusted Cox regression analyses compared allopurinol exposed and non-exposed periods for the risk of AF, controlling for age, sex, race, Charlson-Romano comorbidity index and use of statins, diuretics, ACE inhibitors and β-blockers. HR with 95% CIs was calculated. Sensitivity analyses considered a longer baseline period (365 days vs 183 days) and individual comorbidities.

RESULTS

There were 9244 episodes of incident allopurinol use in 8569 beneficiaries, of which 1366 episodes (14.8%) had incident AF. In multivariable-adjusted analyses, allopurinol use was associated with an HR of 0.83 (95% CI 0.74 to 0.93) for incident AF. In a separate multivariable-adjusted model, compared with no allopurinol use, longer allopurinol use durations were associated with a lower HR of AF: 180 days-2 years, 0.85 (95% CI 0.73 to 0.99) and >2 years, 0.65 (95% CI 0.52 to 0.82). Other factors significantly associated with a higher hazard of AF were: age 75-<85 years and ≥85 years, higher Charlson index score and current β-blocker use. Sensitivity analyses confirmed these findings with minimal/no attenuation of HRs.

CONCLUSIONS

Allopurinol use was associated with a reduced risk of incident AF in the elderly, especially its use for >6 months duration. Future studies should assess the mechanisms underlying this beneficial effect of allopurinol.

Uric acid in metabolic syndrome: From an innocent bystander to a central player

Uric acid, once viewed as an inert metabolic end-product of purine metabolism, has been recently incriminated in a number of chronic disease states, including hypertension, metabolic syndrome, diabetes, non-alcoholic fatty liver disease, and chronic kidney disease. Several experimental and clinical studies support a role for uric acid as a contributory causal factor in these conditions. Here we discuss some of the major mechanisms linking uric acid to metabolic and cardiovascular diseases. At this time the key to understanding the importance of uric acid in these diseases will be the conduct of large clinical trials in which the effect of lowering uric acid on hard clinical outcomes is assessed. Elevated uric acid may turn out to be one of the more important remediable risk factors for metabolic and cardiovascular diseases.

Long-term changes in body weight are associated with changes in blood pressure levels

BACKGROUND AND AIMS

Hypertension and obesity are highly prevalent in Western societies. We investigated the associations of changes in body weight with changes in blood pressure and with incident hypertension, incident cardiovascular events, or incident normalization of blood pressure in patients who were hypertensive at baseline, over a 5-year period.

METHODS AND RESULTS

Data of men and women aged 20-81 years of the Study of Health in Pomerania were used. Changes in body weight were related to changes in blood pressure by linear regression (n = 1875) adjusted for cofounders. Incident hypertension, incident cardiovascular events, or incident blood pressure normalization in patients who were hypertensive at baseline were investigated using Poisson regression (n = 3280) models. A change of 1 kg in body weight was positively associated with a change of 0.45 mm Hg (95% confidence interval (CI): 0.34-0.55 mm Hg) in systolic blood pressure, 0.32 mm Hg (95% CI: 0.25-0.38 mm Hg) in diastolic blood pressure, and 0.36 mm Hg (95% CI: 0.29-0.43 mm Hg) in mean arterial pressure (all p-values <0.001). A 5% weight loss reduced the relative risk (RR) of incident hypertension (RRs 0.84 (95% CI: 0.79-0.89)) and incident cardiovascular events (RRs 0.81 (95% CI: 0.68-0.98)) and increased the chance of incident blood pressure normalization in patients who were hypertensive at baseline by 15% (95% CI: 7-23%).

CONCLUSIONS

Absolute and relative changes in body weight are positively associated with changes in blood pressure levels and also affect the risk of cardiovascular events.