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

Effects of uric acid on ischemic diseases, stratified by lipid levels: a drug-target, nonlinear Mendelian randomization study

Although uric acid-lowering agents such as xanthine oxidase inhibitors have potential cardioprotective effects, studies on their use in preventing cardiovascular diseases are lacking. We investigated the genetically proxied effects of reducing uric acid on ischemic cardiovascular diseases in a lipid-level-stratified population. We performed drug-target Mendelian randomization (MR) analyses using UK Biobank data to select genetic instruments within a uric acid-lowering gene, xanthine dehydrogenase (XDH), and construct genetic scores. For nonlinear MR analyses, individuals were stratified by lipid level. Outcomes included acute myocardial infarction (AMI), ischemic heart disease, cerebral infarction, transient cerebral ischemic attack, overall ischemic disease, and gout. We included 474,983 non-gout individuals with XDH-associated single-nucleotide polymorphisms. The XDH-variant-induced uric acid reduction was associated with reduced risk of gout (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.78-0.93; P < 0.001), cerebral infarction (OR, 0.86; 95% CI, 0.75-0.98; P = 0.023), AMI (OR, 0.79; 95% CI, 0.66-0.94; P = 0.010) in individuals with triglycerides ≥ 188.00 mg/dL, and cerebral infarction in individuals with low-density lipoprotein cholesterol (LDL-C) ≤ 112.30 mg/dL (OR, 0.76; 95% CI, 0.61-0.96; P = 0.020) or LDL-C of 136.90-157.40 mg/dL (OR, 0.67; 95% CI, 0.49-0.92; P = 0.012). XDH-variant-induced uric acid reduction lowers the risk of gout, AMI for individuals with high triglycerides, and cerebral infarction except for individuals with high LDL-C, highlighting the potential heterogeneity in the protective effects of xanthine oxidase inhibitors for treating AMI and cerebral infarction depending on the lipid profiles.

Nanomedicine-Based Therapeutics for Myocardial Ischemic/Reperfusion Injury

Myocardial ischemic/reperfusion (IR) injury is a global cardiovascular disease with high mortality and morbidity. Therapeutic interventions for myocardial ischemia involve restoring the occluded coronary artery. However, reactive oxygen species (ROS) inevitably impair the cardiomyocytes during the ischemic and reperfusion phases. Antioxidant therapy holds great promise against myocardial IR injury. The current therapeutic methodologies for ROS scavenging depend predominantly on administering antioxidants. Nevertheless, the intrinsic drawbacks of antioxidants limit their further clinical transformation. The use of nanoplatforms with versatile characteristics greatly benefits drug delivery in myocardial ischemic therapy. Nanoplatform-mediated drug delivery significantly improves drug bioavailability, increases therapeutic index, and reduces systemic toxicity. Nanoplatforms can be specifically and reasonably designed to enhance molecule accumulation at the myocardial site. The present review initially summarizes the mechanism of ROS generation during the process of myocardial ischemia. The understanding of this phenomenon will facilitate the advancement of innovative therapeutic strategies against myocardial IR injury. The latest developments in nanomedicine for treating myocardial ischemic injury are then discussed. Finally, the current challenges and perspectives in antioxidant therapy for myocardial IR injury are addressed.

Global status and trends in gout research from 2012 to 2021: a bibliometric and visual analysis

BACKGROUND

Gout is the most common inflammatory arthritis with an increasing prevalence and incidence across the globe. We aimed to provide a comprehensive and systematic knowledge map of gout research to determine its current status and trends over the past decade.

METHODS

Publications on gout research were obtained from the Web of Science Core Collection (WOSCC) database. Bibliometric R, VOSviewer, and Citespace were employed to analyze the eligible literature.

RESULTS

A total of 5535 publications concerning gout research between 2012 and 2021 were included. Most publications and citations both numerically came from China. The strongest international cooperation belonged to the USA. The University of Auckland was the most productive institution with a leading place in research collaboration. The prime funding agency was the National Natural Science Foundation of China. Most papers were published in Clinical Rheumatology. Annals of the Rheumatic Diseases achieved the highest number of citations, H-index and IF, which showed the most excellent comprehensive strength. The individual author with the most paper authorship was Dalbeth Nicola with 241 publications and 46 H-index. Keywords and co-citation analysis discovered that pathological mechanism remains the future hotspot in gout research. It may involve gout connection with gut microbiota, NLRP3 inflammasome, xanthine oxidase, and urate-transporter ABCG2. In addition, besides metabolic diseases, the relationship between gout and heart failure may need more attention.

CONCLUSION

This study clarified the current status and research frontier in gout over the past decade, which would provide valuable research references for later researchers. Key Points •We disclosed the current status and frontier directions of gout over the past 10 years worldwide. •We identified future hotspots of gout research, including gout connection with gut microbiota, NLRP3 inflammasome, xanthine oxidase, and urate-transporter ABCG2. •We discovered that the relationship between gout and heart status would be the research frontier.

The effect of allopurinol on cardiovascular outcomes in patients with type 2 diabetes: a systematic review

BACKGROUND

Cardiovascular disease (CVD) remains the main cause of death in patients with type 2 diabetes (T2D). Although hyperuricemia has been associated with multiple CV complications, it is not officially recognized as a target parameter for CVD risk reduction.

AIM

To systematically review the literature in order to determine whether treating hyperuricemia with allopurinol in patients with T2D reduces CVD risk.

METHODS

A thorough literature search in the PubMed, CENTRAL, and EMBASE databases from inception to August 2022 was performed. After application of selection criteria, 6 appropriate studies were identified.

RESULTS

Detailed analysis of the data derived indicated that there is an association between allopurinol treatment and CV benefits, resulting in a reduced risk of CVD events and mortality rates. This association can be attributed mainly to the reduction of inflammation and oxidative burden, as well as to the improvement of glycemic and lipid profiles.

CONCLUSIONS

This systematic review provides evidence that allopurinol may reduce CVD risk in patients with T2D. Randomized, placebo-controlled trials should be performed in order to confirm these findings and identify specific subgroups of patients who will benefit most.

Efficacy and safety of urate-lowering agents in asymptomatic hyperuricemia: systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Asymptomatic hyperuricemia was found to be associated with increased cardiovascular disease risk but the potential benefits of urate-lowering therapy (ULT) remain controversial. We conducted a systematic review and network meta-analysis (NMA) with frequentist model to estimate the efficacy and safety of ULT in asymptomatic hyperuricemia.

METHODS

MEDLINE, Embase, and Scopus were searched without language restrictions. Randomized controlled trials (RCT) of adults with asymptomatic hyperuricemia were eligible if they compared any pair of ULTs (i.e., allopurinol, febuxostat, probenecid, benzbromarone, sulfinpyrazone, rasburicase, lesinurad, and topiroxostat) and placebo or no ULT, and had outcomes of interest, including composite renal events, major adverse cardiovascular events, serum urate levels, estimated glomerular filtration rate (eGFR), systolic blood pressure, and adverse events.

RESULTS

NMA with frequentist approach was applied to estimate relative treatment effects, i.e., risk ratio (RR) and mean difference (MD). A total of 23 RCTs were eligible. NMA identified beneficial effects of ULT on composite renal events and eGFR but not for other outcomes. Allopurinol and febuxostat had significantly lower composite renal events than placebo (RR 0.39, 95% confidence interval [CI] 0.23 to 0.66, and RR 0.68, 95% CI 0.46 to 0.99, respectively). Both treatments also resulted in significantly higher eGFR than placebo (MD 3.69 ml/min/1.73 m², 95% CI 1.31 to 6.08, and MD 2.89 ml/min/1.73 m², 95% CI 0.69 to 5.09, respectively). No evidence of inconsistency was identified.

CONCLUSIONS

Evidence suggests that allopurinol and febuxostat are the ULTs of choice in reducing composite renal events and improving renal function.

TRIAL REGISTRATION

This study was registered with PROSPERO: CRD42019145908. The date of the first registration was 12^th November 2019.

Sex-specific effect of serum urate levels on coronary heart disease and myocardial infarction prevention: A Mendelian randomization study

BACKGROUND AND AIMS

Observational studies have examined serum urate levels in relation to coronary heart disease (CHD) and myocardial infarction (MI). Whether these associations are causal remains controversial, due to confounding factors and reverse causality. We aim to investigate the causality of these associations using Mendelian randomization method.

METHODS AND RESULTS

Instrumental variables were obtained from the largest genome-wide association studies of serum urate (457,690 individuals) to date. Summary statistics were from CARDIoGRAMplusC4D consortium (60,801 CHD cases; 43,676 MI cases), FinnGen (21,012 CHD cases; 12,801 MI cases), UK Biobank (10,157 CHD cases; 7018 MI cases), and Biobank Japan (29,319 CHD cases). Inverse-variance weighted method was applied as the main results. Other statistical methods and reverse MR analysis were conducted in the supplementary analyses. Elevated genetically determined serum urate levels were associated with increased risks of CHD and MI. The association pattern remained for the datasets in FinnGen, the combined results of three independent data sources (CHD: odds ratio (OR), 1.10; 95%CI, 1.06-1.15; p = 4.2 × 10^-6; MI: OR, 1.12; 95%CI, 1.07-1.18; p = 2.7 × 10^-6), and East Asian population. Interestingly, sex-specific subgroup analyses revealed that these associations kept in men only, but not among women in individuals of European ancestry. No consistent evidence was found for the causal effect of CHD or MI on serum urate levels.

CONCLUSION

We provide consistent evidence for the causal effect of genetically predicted serum urate levels on CHD and MI, but not the reverse effect. Urate-lowering therapy may be of cardiovascular benefit in the prevention of CHD and MI, especially for men.

Hyperuricemia in Patients With Coronary Artery Disease and Its Association With Disease Severity

The biochemical background of coronary artery disease (CAD) has been intensively explored in the past several decades. Previous clinical investigations have demonstrated the association of non-traditional risk factors, such as hyperuricemia, with CAD. Studies have shown that increased serum uric acid (SUA) was associated with an increased risk of adverse cardiovascular (CV) outcomes in patients with CAD. While the exact pathophysiological mechanisms leading to increased risk are still unknown, it has been postulated that hyperuricemia leads to endothelial dysfunction, oxidative metabolism, and platelet adhesiveness and aggregation, leading to CAD. Moreover, previous studies have shown that hyperuricemia is an independent risk factor for CAD. However, the correlation between high SUA levels and the severity of CAD remains unclear. The purpose of this review was to elucidate the association of hyperuricemia to CAD severity and to determine the effect of urate-lowering therapy (ULT) on CAD. A search of PubMed up to June 24, 2021, was carried out by the reviewers. From the findings, hyperuricemia stands as an independent risk factor for CAD, and CAD patients treated with ULT had improved CV outcomes and reduced mortality. Therefore, while SUA level is valuable in predicting an augmented risk of CAD and anticipating worse outcomes, ULT has promising cardioprotective effects.

Gout Pharmacotherapy in Cardiovascular Diseases: A Review of Utility and Outcomes

Hyperuricemia and gout have been linked to an increased risk for cardiovascular (CV) disease, stroke, hypertension, heart failure, and chronic kidney disease, possibly through a proinflammatory milieu. However, not all the drugs used in gout treatment improve CV outcomes; colchicine has shown improved CV outcomes in patients with recent myocardial infarction and stable coronary artery disease independent of lipid-lowering effects. There is resurging interest in colchicine following publication of the COLCOT, LoDoCo, LoDoCo2, LoDoCo-MI trials, and COLCORONA trial which will shed light on its utility in COVID-19. Our aim is to review the CV use of colchicine beyond pericardial diseases, as well as CV outcomes of the available gout therapies, including allopurinol and febuxostat. The CARES trial and its surrounding controversies, which lead to the US FDA ‘black box’ warning on febuxostat, in addition to the recent FAST trial which contradicts this and finds febuxostat to be non-inferior, are discussed in this paper.

Allopurinol and cardiovascular events: Time-related biases in observational studies

OBJECTIVE

Several observational studies reported that allopurinol, an effective treatment for gout, was associated with important reductions in cardiovascular events, with calls for large randomized trials, though some results were conflicting. We assessed the extent of time-related biases in these observational studies.

METHODS

We searched the literature for all observational studies reporting on allopurinol and cardiovascular events, focusing on two time-related biases. Time-related confounding bias results from studies using cohorts of patients all exposed to allopurinol, with comparisons based on episodes of allopurinol discontinuation, where confounding factors are not updated over follow-up time. Immortal time bias arises from the exposure misclassification of periods of cohort follow-up during which the outcome under study cannot occur.

RESULTS

We identified 12 studies, of which eight were affected by time-related confounding bias or immortal time bias, while the remaining four studies avoided these biases. The studies affected by time-related confounding bias resulted in significant reductions in the incidence of cardiovascular events with allopurinol use (pooled hazard ratio 0.88; 95% CI: 0.85-0.92), as did the studies affected by immortal time bias (pooled hazard ratio 0.79; 95% CI: 0.72-0.87). The four studies that avoided these biases resulted in a pooled hazard ratio of 1.07 (95% CI: 0.91-1.25).

CONCLUSIONS

Observational studies reporting significantly reduced incidence of cardiovascular events with allopurinol use were affected by time-related biases. Overall, studies that avoided these biases did not find a protective effect. The ALL-HEART randomised trial will provide important and accurate evidence on the potential effectiveness of allopurinol on cardiovascular outcomes.

The Role of Uric Acid in the Acute Myocardial Infarction: A Narrative Review

Increased serum uric acid (SUA) levels have been associated with various pathologic processes such as increased oxidative stress, inflammation, and endothelial dysfunction. Thus, it is not surprising that increased SUA is associated with various adverse outcomes including cardiovascular (CV) diseases. Recent epidemiological evidence suggests that increased SUA may be related to acute myocardial infarction (AMI). Accumulating data also showed that elevated UA has pathophysiological role in the development of AMI. However, there are also studies showing that SUA is not related to the risk of AMI. In this narrative review, we summarized the recent literature data regarding SUA and AMI after providing some background information for the association between UA and coronary artery disease. Future studies will show whether decreasing SUA levels is beneficial for outcomes related to AMI and the optimum SUA levels for best outcomes in CV diseases.

Hyperuricemia in Kidney Disease: A Major Risk Factor for Cardiovascular Events, Vascular Calcification, and Renal Damage

Kidney disease, especially when it is associated with a reduction in estimated glomerular filtration rate, can be associated with an increase in serum urate (uric acid), suggesting that hyperuricemia in subjects with kidney disease may be a strictly secondary phenomenon. Mendelian randomization studies that evaluate genetic scores regulating serum urate also generally have not found evidence that serum urate is a causal risk factor in chronic kidney disease. Nevertheless, this is countered by a large number of epidemiologic, experimental, and clinical studies that have suggested a potentially important role for uric acid in kidney disease and cardiovascular disease. Here, we review the topic in detail. Overall, the studies strongly suggest that hyperuricemia does have an important pathogenic role that likely is driven by intracellular urate levels. An exception may be the role of extracellular uric acid in atherosclerosis and vascular calcification. One of the more striking findings on reviewing the literature is that the primary benefit of lowering serum urate in subjects with CKD is not by slowing the progression of renal disease, but rather by reducing the incidence of cardiovascular events and mortality. We recommend large-scale clinical trials to determine if there is a benefit in lowering serum urate in hyperuricemic subjects in acute and chronic kidney disease and in the reduction of cardiovascular morbidity and mortality in subjects with end-stage chronic kidney disease.

Refractory Angina-Unsolved Problem

The article discusses pharmacologic and interventional therapeutic options for patients with refractory angina. Refractory angina refers to long-lasting symptoms (≥3 months) due to established reversible ischemia in the presence of obstructive coronary artery disease, which cannot be controlled by escalating medical therapy with second-line and third-line pharmacologic agents, bypass grafting, or stenting. Due to an aging population, increased number of comorbidities, and advances in coronary artery disease treatment, incidence of refractory angina is growing. Although the number of therapeutic options is increasing, there is a lack of randomized clinical trials that could help create recommendations for this group of patients.

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.

Uric Acid and Hypertension: An Update With Recommendations

The association between increased serum urate and hypertension has been a subject of intense controversy. Extracellular uric acid drives uric acid deposition in gout, kidney stones, and possibly vascular calcification. Mendelian randomization studies, however, indicate that serum urate is likely not the causal factor in hypertension although it does increase the risk for sudden cardiac death and diabetic vascular disease. Nevertheless, experimental evidence strongly suggests that an increase in intracellular urate is a key factor in the pathogenesis of primary hypertension. Pilot clinical trials show beneficial effect of lowering serum urate in hyperuricemic individuals who are young, hypertensive, and have preserved kidney function. Some evidence suggest that activation of the renin-angiotensin system (RAS) occurs in hyperuricemia and blocking the RAS may mimic the effects of xanthine oxidase inhibitors. A reduction in intracellular urate may be achieved by lowering serum urate concentration or by suppressing intracellular urate production with dietary measures that include reducing sugar, fructose, and salt intake. We suggest that these elements in the western diet may play a major role in the pathogenesis of primary hypertension. Studies are necessary to better define the interrelation between uric acid concentrations inside and outside the cell. In addition, large-scale clinical trials are needed to determine if extracellular and intracellular urate reduction can provide benefit hypertension and cardiometabolic disease.

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.

Cardiovascular Disease in Gout and the Protective Effect of Treatments Including Urate-Lowering Therapy

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.

Molecular Understanding of the Cardiomodulation in Myocardial Infarction and the Mechanism of Vitamin E Protections

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Myocardial infarction is a major cause of deaths globally. Modulation of several molecular mechanisms occurs during the initial stages of myocardial ischemia prior to permanent cardiac tissue damage, which involves both pathogenic as well as survival pathways in the cardiomyocyte. Currently, there is increasing evidence regarding the cardioprotective role of vitamin E in alleviating the disease. This fat-soluble vitamin does not only act as a powerful antioxidant; but it also has the ability to regulate several intracellular signalling pathways including HIF-1, PPAR-γ, Nrf-2, and NF-κB that influence the expression of a number of genes and their protein products. Essentially, it inhibits the molecular progression of tissue damage and preserves myocardial tissue viability. This review aims to summarize the molecular understanding of the cardiomodulation in myocardial infarction as well as the mechanism of vitamin E protection.

Allopurinol use associated with increased risk of acute myocardial infarction in older people in a case-control study

Objective

There is controversy about the association between the allopurinol use and the risk of acute myocardial infarction. The aim of the study was to examine the association between allopurinol use and acute myocardial infarction in older people in Taiwan.

Materials and Methods

We used the 2000-2013 database of the Taiwan National Health Insurance Program to conduct a case-control study. Cases were assigned as subjects aged 65 years and older with the first incident acute myocardial infarction. Matched controls were assigned as subjects aged 65 years and older without any type of coronary artery disease. Ever use of allopurinol was defined as subjects who had at least a prescription of allopurinol before the diagnosis date of first incident acute myocardial infarction. The odds ratio (OR) and the 95% confidence interval (CI) for acute myocardial infarction associated with allopurinol use were estimated by the multivariable logistic regression model.

Results

There were 4701 cases with the first incident acute myocardial infarction and 9369 matched controls. The adjusted OR of acute myocardial infarction was 2.2 (95% CI 1.7- 2.7) for subjects with ever use of allopurinol, compared with never use. The adjusted ORs of acute myocardial infarction were 2.0 (95% CI 1.5-2.6) for subjects with average daily dosage of allopurinol <200 mg and 2.5 (95% CI 1.6-4.0) for subjects with average daily dosage of allopurinol ≥200 mg.

Conclusion

Allopurinol use is associated with increased odds of acute myocardial infarction in older people, which is dosage dependent.

lncRNA ANRIL protects H9c2 cells against hypoxia-induced injury through targeting the miR-7-5p/SIRT1 axis

BACKGROUND

Acute myocardial infarction (AMI) occurred in the heart, which underwent long-term ischemia, and was mainly caused by hypoxia. Recently, studies have uncovered the participation of long noncoding RNAs (lncRNAs) in the pathogenesis of heart disease. Here, we planned to probe the role and molecular basis of ANRIL in hypoxia-induced H9c2 cell injury.

METHODS

Trypan blue exclusion assay and Transwell and flow cytometry assays were conducted to assess hypoxia-induced injury by determining the viability, migration, invasion, and apoptosis of H9c2 cells in different conditions, respectively. Gene expressions were evaluated by quantitative real-time polymerase chain reaction or western blot analysis as needed. RNA immunoprecipitation and luciferase reporter assays were applied to confirm the associations among genes.

RESULTS

ANRIL expression was dramatically enhanced in hypoxia-injured H9c2 cells, and silencing ANRIL aggravated hypoxia-induced H9c2 cell injury. ANRIL positively regulated sirtuin 1 (SIRT1) expression via competitively binding with miR-7-5p. Moreover, inhibition of miR-7-5p counteracted ANRIL depletion-exacerbated injury in hypoxic H9c2 cells, meanwhile, forced SIRT1 expression attenuated the injury-promoting effect of miR-7-5p upregulation on hypoxic H9c2 cells.

CONCLUSION

Our findings disclosed that ANRIL plays a protective part in hypoxia-induced H9c2 cell injury via modulating the miR-7-5p/SIRT1 axis, suggesting the great potential of ANRIL as a protective target for AMI.

Effectiveness of Statins as Primary Prevention in People With Gout: A Population-Based Cohort Study

BACKGROUND

Cardiovascular guidelines do not give firm recommendations on statin therapy in patients with gout because evidence is lacking.

AIM

To analyze the effectiveness of statin therapy in primary prevention of coronary heart disease (CHD), ischemic stroke (IS), and all-cause mortality in a population with gout.

METHODS

A retrospective cohort study (July 2006 to December 2017) based on Information System for the Development of Research in Primary Care (SIDIAP^Q), a research-quality database of electronic medical records, included primary care patients (aged 35-85 years) without previous cardiovascular disease (CVD). Participants were categorized as nonusers or new users of statins (defined as receiving statins for the first time during the study period). Index date was first statin invoicing for new users and randomly assigned to nonusers. The groups were compared for the incidence of CHD, IS, and all-cause mortality, using Cox proportional hazards modeling adjusted for propensity score.

RESULTS

Between July 2006 and December 2008, 8018 individuals were included; 736 (9.1%) were new users of statins. Median follow-up was 9.8 years. Crude incidence of CHD was 8.16 (95% confidence interval [CI]: 6.25-10.65) and 6.56 (95% CI: 5.85-7.36) events per 1000 person-years in new users and nonusers, respectively. Hazard ratios were 0.84 (95% CI: 0.60-1.19) for CHD, 0.68 (0.44-1.05) for IS, and 0.87 (0.67-1.12) for all-cause mortality. Hazard for diabetes was 1.27 (0.99-1.63).

CONCLUSIONS

Statin therapy was not associated with a clinically significant decrease in CHD. Despite higher risk of CVD in gout populations compared to general population, patients with gout from a primary prevention population with a low-to-intermediate incidence of CHD should be evaluated according to their cardiovascular risk assessment, lifestyle recommendations, and preferences, in line with recent European League Against Rheumatism recommendations.

Association between allopurinol and cardiovascular outcomes and all-cause mortality in diabetes: A retrospective, population-based cohort study

AIM

To assess the association between allopurinol and mortality and cardiovascular outcomes in an allopurinol-treated diabetes cohort.

MATERIALS AND METHODS

We conducted a population-based retrospective cohort study in Ontario, Canada. Eligible subjects were ≥ 66 years old with diabetes and a first prescription for allopurinol between 1 April, 2002 and 31 March, 2012 and were followed until 31 March, 2016. The primary outcome was a composite: all-cause mortality, non-fatal cardiovascular event (myocardial infarction, revascularization procedure, or stroke) or congestive heart failure (CHF). Secondary outcomes were components of the primary outcome and pneumonia as a negative tracer. Allopurinol was modelled as time-varying exposed versus unexposed, daily dose category and cumulative dose using sex-specific multivariable Cox proportional hazards models.

RESULTS

Over a median follow-up of 4.65 years (interquartile range 1.79-7.81), 16 266/23 103 males and 10 571/15 313 females experienced the primary outcome. Allopurinol was associated with a reduction in the primary outcome [adjusted hazard ratios (aHR) 0.77 (95% confidence interval 0.75-0.80) and 0.81 (0.78-0.84) for males and females, respectively], driven by marked reductions in all-cause mortality and modest reductions in cardiovascular events/CHF. There was no effect of cumulative allopurinol dose on any outcome, and allopurinol was also associated with reduced risk of pneumonia in males [aHR 0.88 (0.83, 0.93)].

CONCLUSIONS

Allopurinol was associated with reduced mortality and cardiovascular outcomes. However, lack of cumulative dose effect and a positive tracer outcome in males suggests residual bias. Future research assessing whether allopurinol prevents vascular complications in diabetes requires a clinical trial.

Shortage of Cellular ATP as a Cause of Diseases and Strategies to Enhance ATP

Germline mutations in cellular-energy associated genes have been shown to lead to various monogenic disorders. Notably, mitochondrial disorders often impact skeletal muscle, brain, liver, heart, and kidneys, which are the body’s top energy-consuming organs. However, energy-related dysfunctions have not been widely seen as causes of common diseases, although evidence points to such a link for certain disorders. During acute energy consumption, like extreme exercise, cells increase the favorability of the adenylate kinase reaction 2-ADP -> ATP+AMP by AMP deaminase degrading AMP to IMP, which further degrades to inosine and then to purines hypoxanthine -> xanthine -> urate. Thus, increased blood urate levels may act as a barometer of extreme energy consumption. AMP deaminase deficient subjects experience some negative effects like decreased muscle power output, but also positive effects such as decreased diabetes and improved prognosis for chronic heart failure patients. That may reflect decreased energy consumption from maintaining the pool of IMP for salvage to AMP and then ATP, since de novo IMP synthesis requires burning seven ATPs. Similarly, beneficial effects have been seen in heart, skeletal muscle, or brain after treatment with allopurinol or febuxostat to inhibit xanthine oxidoreductase, which catalyzes hypoxanthine -> xanthine and xanthine -> urate reactions. Some disorders of those organs may reflect dysfunction in energy-consumption/production, and the observed beneficial effects related to reinforcement of ATP re-synthesis due to increased hypoxanthine levels in the blood and tissues. Recent clinical studies indicated that treatment with xanthine oxidoreductase inhibitors plus inosine had the strongest impact for increasing the pool of salvageable purines and leading to increased ATP levels in humans, thereby suggesting that this combination is more beneficial than a xanthine oxidoreductase inhibitor alone to treat disorders with ATP deficiency.

A meta-analysis of the efficacy of allopurinol in reducing the incidence of myocardial infarction following coronary artery bypass grafting

Background

The xanthine oxidase inhibitor allopurinol that is commonly used to treat gout, has been suggested to have pleiotropic effects that are likely to reduce the incidence of myocardial infarction (MI) in at risk individuals. The aim of this meta-analysis was to assess the efficacy of allopurinol treatment in reducing the incidence of MI.

Method

MEDLINE, Scopus, Web of Science, and Cochrane Library databases were searched for randomised controlled trials examining the efficacy of allopurinol in reducing the incidence of MI. The quality of study methodology was assessed by two independent reviewers using the Cochrane Collaboration’s tool for assessing risk of bias. This meta-analysis was conducted using a fixed-effects model, and heterogeneity was assessed with the I² index.

Results

One thousand one hundred twenty-three citations were screened and only six studies satisfied the inclusion criterion. Published between 1988 and 1995, all studies examined the cardioprotective efficacy of allopurinol in the setting of coronary artery bypass graft (CABG). From a total pooled sample size of 229, MI was reported in 2 (1.77%) allopurinol and 14 (12.07%) control patients. A fixed-effects meta-analysis (I² = 0%) identified a statistically significant reduced incidence of myocardial infarction (RR 0.21, 95% CI: 0.06, 0.70, p = 0.01) in patients allocated to allopurinol. However, in the leave-one-out sensitivity analyses, the treatment effect became non-significant with the removal of one of the studies.

Conclusion

Based on the limited evidence available, allopurinol appears to reduce the incidence of perioperative MI following CABG. Further research is required to confirm these findings.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0881-6) contains supplementary material, which is available to authorized users.

MicroRNA-210 aggravates hypoxia-induced injury in cardiomyocyte H9c2 cells by targeting CXCR4

BACKGROUND

Myocardial infarction (MI), a leading cause of mortality, is identified as the myocardial necrosis due to prolonged ischemia. Hypoxia, resulting from ischemia, induces cell apoptosis during MI. Since miR-210 is a hypoxia inducible factor, we aimed to explore the functional role of miR-210 in hypoxic H9c2 cells.

METHODS

Hypoxia-induced cell injury was evaluated according to cell viability, apoptosis and expression of apoptosis-associated proteins. miR-210 expression after hypoxia was tested. Then, miR-210 was overexpressed or silenced, and its effects on viability and apoptosis of H9c2 cells under normoxia and hypoxia were measured. Utilizing bioinformatics method, possible target genes of miR-210 were screened, and the interaction between miR-210 and target gene was investigated. Moreover, the effect of co-transfections with microRNAs and small interfering RNAs on hypoxia-induced cell injury as well as the possible involved signaling pathways was also determined.

RESULTS

Hypoxia induced cell injury and up-regulation of miR-210 in H9c2 cells. Hypoxia-induced cell injury was aggravated by miR-210 overexpression but was attenuated by miR-210 suppression. CXC chemokine receptor 4 (CXCR4) was a target gene of miR-210, and CXCR4 inhibition could reverse the effects of miR-210 inhibition on H9c2 cells. Furthermore, the key kinases involved in the SMAD and mTOR signaling pathways were down-regulated by hypoxia, and the down-regulations were reversed by miR-210 suppression through modulating CXCR4.

CONCLUSION

miR-210 was up-regulated in hypoxic H9c2 cells. Suppression of miR-210 attenuated hypoxia-induced cell injury in H9c2 cells by targeting CXCR4, along with activations of the SMAD and mTOR signaling pathways.

Allopurinol and the risk of incident peripheral arterial disease in the elderly: a US Medicare claims data study

Objective

The aim was to examine whether allopurinol use is independently associated with a reduction in the risk of incident peripheral arterial disease (PAD) in the US elderly.

Methods

We used the 5% random Medicare sample from 2006 to 2012 to examine the association of allopurinol use and duration of use with the risk or hazard of incident PAD in a retrospective cohort study using a new user design. Multivariable Cox regression models adjusted for demographics, co-morbidity, cardiac medications and cardiac conditions. Hazard ratios (HRs) and 95% CIs were calculated.

Results

We identified 26 985 episodes of incident allopurinol use in 25 282 beneficiaries; 3167 allopurinol use episodes (12%) ended in incident PAD. In multivariable-adjusted analyses, allopurinol use was associated with an HR of 0.88 (95% CI: 0.81, 0.95) for incident PAD, as was female gender, HR 0.84 (95% CI: 0.78, 0.90). In a separate multivariable-adjusted model, compared with no allopurinol use, longer durations of allopurinol use were associated with lower HR of PAD: 181 days to 2 years, 0.88 (95% CI: 0.79, 0.97); and >2 years, 0.75 (95% CI: 0.63, 0.89). Other factors significantly associated with a higher HR of PAD were age 75 to < 85 and ⩾85 years, higher Charlson index score and black race. Sensitivity analyses that adjusted for cardiac conditions and medications confirmed these findings, with minimal to no attenuation of HRs.

Conclusion

New allopurinol use was independently associated with a lower risk of PAD in the elderly. Longer allopurinol use durations seemed more protective. Mechanisms of the protective effect need to be investigated in future studies.

An evaluation of longitudinal changes in serum uric acid levels and associated risk of cardio-metabolic events and renal function decline in gout

OBJECTIVE

Gout patients have a high burden of co-morbid conditions including diabetes mellitus (DM), chronic kidney disease (CKD), and cardiovascular disease (CVD). We sought to evaluate the association between changes in serum uric acid (SUA) levels over time and the risk of incident DM, CVD, and renal function decline in gout patients.

METHODS

An observational cohort study was conducted among enrollees of private health insurance programs in the US between 2004 and 2015. Gout patients were included on the index date of a SUA measurement ≥6.8 mg/dl. The exposure of interest was cumulative change in SUA levels from baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for incident DM, incident CVD, and renal function decline (≥30% reduction in glomerular filtration rate) were derived using marginal structural models with stabilized inverse probability weights accounting for baseline confounders (age, gender, co-morbidities, co-medications) and time-varying confounders (serum creatinine, blood urea nitrogen, glycated hemoglobin).

RESULTS

Among 26,341 patients with gout, the average age was 62, 75% were men, and the median baseline SUA was 8.6 mg/dl (interquartile range 7.7 to 9.5). The incidence rates/100 person-years (95% CI) were 1.63 (1.51-1.75) for DM, 0.77 (0.70-0.84) for CVD, and 4.32 (4.14-4.49) for renal function decline. The adjusted HR (95% CI) per 3 mg/dl reduction in SUA, corresponding on average to achieving the target level of <6 mg/dl in this population, was 1.04 (0.92-1.17) for DM, 1.07 (0.89-1.29) for CVD, and 0.85 (0.78-0.92) for renal function decline.

CONCLUSIONS

Reduction in SUA in patients with gout may be associated with a reduced risk of renal function decline, but not with DM or CVD.

Xanthine oxidase inhibitors for prevention of cardiovascular events: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Xanthine oxidase inhibitors (XOI), classified as purine-like (allopurinol and oxypurinol) and non-purine (febuxostat and topiroxostat) XOI, present antioxidant properties by reducing the production of reactive oxygen species derived from purine metabolism. Oxidative stress is an important factor related to endothelial dysfunction and ischemia-reperfusion injury, and may be implicated in the pathogenesis of heart failure, hypertension, and ischemic heart disease. However, there is contradictory evidence regarding the possible cardiovascular (CV) protective effect exerted by XOI. Our objective is to compare the incidence of major adverse cardiovascular events (MACE), mortality, total (TCE) and specific CV events in randomized controlled trials (RCTs) testing XOI against placebo or no treatment.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Central, Lilacs databases were searched from inception to Dec 30 2016, along with hand searching. RCTs including exclusively adult individuals, lasting ≥ 4 weeks, with no language restriction, were eligible. Independent paired researchers selected studies and extracted data. Considering the expected rarity of events, Peto and DerSimonian/Laird odds ratios (OR), the latter in case of heterogeneity, were used for analysis. Random-effects meta-regression was used to explore heterogeneity.

RESULTS

The analysis of MACE included 81 articles (10,684 patients, 6434 patient-years). XOI did not significantly reduce risk of MACE (ORP = 0.71, 95% CI 0.46-1.09) and death (0.89, 0.59-1.33), but reduced risk of TCE (0.60, 0.44-0.82; serious TCE: 0.64, 0.46 to 0.89), and hypertension (0.54, 0.37 to 0.80). There was protection for MACE in patients with previous ischemic events (0.42, 0.23-0.76). Allopurinol protected for myocardial infarction (0.38, 0.17-0.83), hypertension (0.32, 0.18-0.58), TCE (0.48, 0.31 to 0.75, I2 = 55%) and serious TCE (0.56, 0.36 to 0.86, I2 = 44%). Meta-regression associated increasing dose of allopurinol with higher risk of TCE and serious TCE (P < 0.05). Accordingly, lower doses (≤ 300 mg/day) of allopurinol reduced the risk of TCE, unlike higher doses. Non-purine-like XOI did not significantly reduce or increase the risk of adverse CV events, but confidence intervals were wide. Quality of evidence was generally low to moderate.

CONCLUSIONS

Purine-like XOI may reduce the incidence of adverse CV outcomes. However, higher doses of allopurinol (> 300 mg/day) may be associated with loss of CV protection.

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.