Uric acid and coronary artery disease: An elusive link deserving further attention

Sex differences in the association of the uric acid to high-density lipoprotein cholesterol ratio with coronary artery disease risk among Chinese nondialysis patients with CKD stages 3-5

BACKGROUND AND AIMS

Evidence has indicated that serum uric acid (UA) and high-density lipoprotein cholesterol (HDL-C) are positively and negatively associated with coronary artery disease (CAD). The UA to HDL-C ratio (UHR) has recently drawn attention as a new predictor for metabolic syndrome, inflammation and atherosclerosis. However, the association between the UHR and CAD in nondialysis chronic kidney disease (CKD) patients is still unclear.

METHODS AND RESULTS

We retrospectively analysed 733 nondialysis patients with CKD stage 3-5 who received their first coronary artery angiography (CAG), including 510 participants with CAD. All laboratory indicators were collected within one week before CAG. The median UHR of CAD and non-CAD patients was 15.52% and 12.29%, respectively. In multivariate analysis, female patients with a high UHR were 4.7 times more at risk of CAD than those with a lower UHR. Meanwhile, the positive association of the UHR with the severity of coronary artery stenosis (CAS) persisted significantly in female CAD subjects but not in males. In addition, receiver operating characteristic (ROC) curves were constructed for CAD and severe CAS. The area under the curve (AUC) for the UHR was higher than that for UA and HDL-C alone in female patients [UHR (AUC): 0.715 for CAD and 0.716 for severe CAS].

CONCLUSIONS

An elevated UHR was independently related to an increased CAD risk and the severity of CAS in nondialysis female patients with CKD stage 3-5, and was more predictive of the onset of CAD and the severity of CAS than UA or HDL-C alone.

Relation Between Serum Uric Acid to Albumin Ratio and Severity of Chronic Coronary Artery Disease

Uric acid (UA) to albumin ratio (UAR) is an emerging marker to predict coronary artery disease (CAD)-related events. There is limited data on the relationship between UAR and the severity of the disease in chronic CAD patients. We aimed to evaluate UAR as an indicator for CAD severity using the Syntax score (SS). We retrospectively enrolled 558 patients with stable angina pectoris and underwent coronary angiography (CAG). Patients were divided into 2 groups, according to CAD severity: low SS (≤22) and intermediate-high SS (>22) groups. UA levels were higher and albumin levels were lower in the intermediate-high SS score group (P < .001). UAR levels were significantly higher in the intermediate-high SS group (P < .001). Also, there was a significant correlation between UAR levels and SS (r = .55, 95% confidence interval (CI): .49-.60, P < .001). In multivariable analysis, UAR >1.34 (Odds ratio, 3.8 [2.3-6.2]; P < .001) was an independent predictor of intermediate-high SS while albumin and UA levels were not. In conclusion, UAR predicted disease burden in chronic CAD patients. It may prove useful as a simple and readily available marker to select patients for further evaluation.

Association between uric acid and cardiac outcomes mediated by neutrophil-to-lymphocyte ratio in patients with left ventricular diastolic dysfunction and pulmonary hypertension

To evaluate the association of uric acid (UA) with adverse outcomes and its potential mediator in patients with left ventricular diastolic dysfunction (LVDD) and pulmonary hypertension (PH). We retrospectively analyzed 234 patients with LVDD and PH. The baseline characteristics of patients with low UA (≤ 330 µmol/L) group were compared with high UA (> 330 µmol/L) group. Adverse outcomes included all-cause mortality, cardiac death and heart failure (HF) hospitalization. Their association with UA and the mediator were evaluated using Cox regression and mediation analysis. The mediation proportion was further quantified by the R mediation package. During a mean follow-up of 50 ± 18 months, there were 27 all-cause deaths, 18 cardiovascular deaths and 41 incidents of HF hospitalization. Multivariable Cox regression analysis showed UA was an independent risk factor of adverse outcomes in LVDD and PH patients, even after adjusting for age, sex, body mass index, medical histories, systolic blood pressure, fasting blood glucose, total cholesterol, triglyceride, eGFR, BNP and medications. The hazard ratios (HRs) for UA (per 10 µmol/L increase) were as below: for all-cause mortality, HR 1.143, 95% CI 1.069-1.221, P < 0.001; for cardiac death, HR 1.168, 95% CI 1.064-1.282, P = 0.001; for HF hospitalization, HR 1.093, 95% CI 1.035-1.155, P = 0.001. Neutrophil-to-lymphocyte ratio (NLR) played a partial mediation role in the association, and the mediation proportion for NLR on the UA-adverse outcomes were 21%, 19% and 17%, respectively. In patients of LVDD with PH, higher UA level was independently correlated with adverse outcomes. Furthermore, NLR partially mediated the effect of UA on the risk of all-cause mortality, cardiac death and HF hospitalization.

Salivary uric acid across child development and associations with weight, height, and body mass index

Introduction

Obesity during childhood is a serious and growing chronic disease with consequences for lifelong health. In an effort to advance research into the preclinical indicators of pediatric obesity, we examined longitudinal assessments of uric acid concentrations in saliva among a cohort of healthy children from age 6-months to 12-years (n's per assessment range from 294 to 727).

Methods

Using data from a subsample of participants from the Family Life Project (an Environmental influences on Child Health Outcomes Program cohort), we: (1) characterized salivary uric acid (sUA) concentrations from infancy to early adolescence by sex and race; (2) assessed changes in sUA levels across development; and (3) evaluated associations between sUA concentrations and measures of child weight, height, and body mass index (BMI). Across four assessments conducted at 6-, 24-, 90-, and 154-months of age, 2,000 saliva samples were assayed for UA from 781 participants (217 participants had sUA data at all assessments).

Results

There were no significant differences in sUA concentrations by sex at any assessment, and differences in sUA concentrations between White and non-White children varied by age. At the 90- and 154-month assessments, sUA concentrations were positively correlated with measures of child weight, height, and BMI (90-month: weight- ρ(610) = 0.13, p < 0.01; height- ρ(607) = 0.10, p < 0.05; BMI- ρ(604) = 0.13, p < 0.01; 154-month: weight- ρ(723) = 0.18, p < 0.0001; height- ρ(721) = 0.10, p < 0.01; BMI- ρ(721) = 0.17, p < 0.0001). Group based trajectory modeling identified two groups of children in our sample with distinct patterns of sUA developmental change. The majority (72%) of participants showed no significant changes in sUA across time ("Stable" group), while 28% showed increases in sUA across childhood with steep increases from the 90- to 154-month assessments ("Increasing" group). Children in the Increasing group exhibited higher sUA concentrations at all assessments (6-month: t(215) = -5.71, p < 0.001; 24-month: t(215) = -2.89, p < 0.01; 90-month: t(215) = -3.89, p < 0.001; 154-month: t(215) = -19.28, p < 0.001) and higher weight at the 24- and 90-month assessments (24-month: t(214) = -2.37, p < 0.05; 90-month: t(214) = -2.73, p < 0.01).

Discussion

Our findings support the potential utility of sUA as a novel, minimally-invasive biomarker that may help advance understanding of the mechanisms underlying obesity as well as further surveillance and monitoring efforts for pediatric obesity on a large-scale.

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.

Integrated metabolomics and network pharmacology to reveal the mechanisms of Guizhi-Fuling treatment for myocardial ischemia

Myocardial ischemia is a cardio-physiological condition caused by a decrease in blood perfusion to the heart, resulting in reduced oxygen supply and abnormal myocardial energy metabolism. Guizhi-Fuling (GZFL) is effective in treating Myocardial ischemia. However, its mechanism of action remains unclear and requires further exploration. we hope to reveal the mechanisms of GZFL treating Myocardial ischemia by integrating metabolomics and network pharmacology. In this study, myocardial metabolomic analysis was first performed using GC-MS to discover the potential mechanism of action of GZFL on myocardial ischemia. Then, network pharmacology was used to analyze key pathways and construct a pathway-core target network. Molecular docking was used to validate core targets in network pharmacological signaling pathways. Finally, western blots were used to verify core targets of metabolomics and network pharmacology integrated pathways as well as key targets in signaling pathways. As a result, we identified 22 important biomarkers of GZFL for the treatment of myocardial ischemia. Most of these metabolites were restored by modulation after GZFL treatment. Based on the network pharmacology, 297 targets of GZFL in the treatment of myocardial ischemia were obtained. The further comprehensive analysis focused on 3 key targets, including Tyrosine hydroxylase (TH), myeloperoxidase (MPO), and phosphatidylinositol 3-kinases (PIK3CA), and their associated metabolites and pathways. Compared with the model group, the protein expression levels of TH, MPO and PIK3CA were decreased in GZFL. Therefore, the mechanism of GZFL for treating myocardial ischemia may be to inhibit myocardial inflammatory factors, reduce myocardial inflammation, and restore endothelial function, while regulating norepinephrine release and uric acid concentration.

Can hyperuricemia predict the progression risk of cerebral small vessel disease?

AIMS

Uric acid (UA) may play a crucial role in the process of cerebral small vessel disease (SVD), but few follow-up studies have focused on the effect of UA in the progression of SVD. The present study aimed to ascertain whether serum UA levels are associated with the risk of SVD progression.

METHODS

We performed an observational clinical study in adults older than 45 years with cranial magnetic resonance imaging (MRI) from 30 October 2015, to 28 January 2021. The patients were divided into two groups according to whether their total burden of SVD scores increased or not during the follow-up: SVD progression (increased by at least one point) and without SVD progression (increased 0 points). Cox regression and Kaplan-Meier survival analyses were used for univariate analysis between groups to identify the risk factors for SVD progression.

RESULTS

Ultimately, 261 eligible patients were included in the final analysis. Of the 261 eligible patients, 73 were included in the SVD progression group, and 188 were included in the group without SVD progression. Correlation analysis found that the levels of UA and the ratio of hyperuricemia (HUA) showed statistically significant correlations with SVD progression risk (r = 0.197 and Crammer's V = 0.213, respectively, P < 0.01). Cox regression and Kaplan-Meier survival analyses showed that after adjustment for covariates, HUA was an independent risk factor for the incidence of SVD progression. The risk of SVD progression in patients with HUA was higher than that in those without HUA (HR (95% CI), 1.77 (1.03-3.05), P < 0.05).

CONCLUSIONS

High serum UA levels are independently related to the risk of SVD progression, thus highlighting not only the influence of traditional risk factors such as hypertension and age on SVD but also the UA levels of patients for individualized treatment.

Impact of serum uric acid levels on the clinical prognosis and severity of coronary artery disease in patients with acute coronary syndrome and hypertension after percutaneous coronary intervention: a prospective cohort study

OBJECTIVE

The impact of serum uric acid (sUA) levels on the clinical prognosis and severity of coronary artery disease in patients with acute coronary syndrome (ACS) and hypertension after percutaneous coronary intervention (PCI) is not fully clear. This study aimed to assess the association among sUA levels, clinical prognosis and severity of coronary artery disease in patients with ACS and hypertension after PCI.

DESIGN

In this prospective cohort study, we followed-up patients with ACS and hypertension after PCI for 1 year to explore the risk factors for 1 year total major adverse cardiovascular events (MACEs) and multivessel coronary artery disease, the dose-effect relationship among sUA levels, MACEs and severity of coronary artery disease and correlation between sUA levels and severity of coronary artery disease (Gensini score).

SETTING/PATIENTS

Several Chinese internists followed-up 422 patients who were diagnosed with ACS and hypertension after PCI in a large tertiary hospital of Qingdao during the period from 1 June 2019 to 1 December 2019.

OUTCOME MEASURES

One-year follow-up MACEs results and coronary angiography results.

RESULTS

In the coronary angiography results, multivessel coronary artery disease (28.5% vs 21.4%, p=0.006) and non-culprit lesion vascular occlusion (11.7% vs 5.3%, p=0.042) were more common in the hyperuricaemia group, and the Gensini score (26.69±13.46 vs 17.66±10.57, p<0.001) was also higher. In the results of 1-year MACEs, the incidence of all-cause mortality (3.5% vs 2.5%, p=0.037), PCI or coronary artery bypass grafting therapy due to myocardial infarction or angina pectoris (15.1% vs 7.6%, p=0.027), medication conservative therapy in hospital due to myocardial infarction or angina pectoris (12.9% vs 6.7%, p=0.041) and total MACEs (31.8% vs 16.9%, p=0.001) were higher in patients with hyperuricaemia. Univariate and multivariate logistic regression analysis models showed that hyperuricaemia was still an independent risk factor for total MACEs within 1 year (OR=2.618, 95% CI 1.656 to 4.139, p<0.001; OR=1.920, 95% CI 1.158 to 3.183, p=0.011, respectively) and multivessel coronary artery disease (OR=2.140, 95% CI 1.371 to 3.342, p=0.001; OR=1.688, 95% CI 1.051 to 2.710, p=0.030, respectively) after adjusting for confounding factors. The severity of coronary artery disease (non-culprit lesion vascular occlusion (4.7% vs 8.4% vs 9.6% vs 16.2%, p=0.041); multivessel coronary artery disease (17.9% vs 22.4% vs 29.8% vs 35.2%, p=0.022); Gensini score (16.96±10.35 vs 19.31±10.63 vs 26.12±11.48 vs 33.33±14.01, p<0.001)) and the incidence of total MACEs (13.2% vs 14.2% vs 34.6% vs 41%, p<0.001) increased significantly with the sUA levels increasing. Further, the Gensini score was positively correlated with uric acid levels (r=0.515, p<0.001).

CONCLUSIONS

Hyperuricaemia is an independent risk factor for 1-year total MACEs and multivessel coronary artery disease in patients with ACS and hypertension after PCI.

Characterizing and Evaluating Diurnal Salivary Uric Acid Across Pregnancy Among Healthy Women

Uric acid levels during pregnancy have been examined as a potential indicator of risk for gestational diabetes mellites, hypertension, and related adverse birth outcomes. However, evidence supporting the utility of serum uric acid levels in predicting poor maternal and fetal health has been mixed. The lack of consistent findings may be due to limitations inherent in serum-based biomeasure evaluations, such as minimal repeated assessments and variability in the timing of these assessments. To address these gaps, we examined repeated measurements of diurnal salivary uric acid (sUA) levels in a sample of 44 healthy women across early-mid and late pregnancy. We assessed potential covariates and confounds of sUA levels and diurnal trajectories, as well as associations between maternal weight gain and blood pressure during pregnancy and sUA concentrations. Using multilevel linear models, we found sUA increased across pregnancy and displayed a robust diurnal pattern with the highest concentrations at waking, a steep decline in the early morning, and decreasing levels across the day. Maternal pre-pregnancy BMI, age, prior-night sleep duration, and fetal sex were associated with sUA levels and/or diurnal slopes. Maternal blood pressure and gestational weight gain also showed significant associations with sUA levels across pregnancy. Our results expand upon those found with serum UA measurements. Further, they demonstrate the feasibility of using at-home, minimally-invasive saliva sampling procedures to track UA levels across pregnancy with potential applications for the long-term monitoring of maternal cardiometabolic risk.

Hyperuricemia as a prognostic marker for long-term outcomes in patients with myocardial infarction with nonobstructive coronary arteries

Background

Hyperuricemia (HUA) has been proved as a predictor of worse outcomes in patients with coronary artery disease. Here, we investigated the prognostic value of HUA in a distinct population with myocardial infarction with nonobstructive coronary arteries (MINOCA).

Methods

A total of 1179 MINOCA patients were enrolled and divided into HUA and non-HUA groups. HUA was defined as a serum uric acid level ≥ 420 μmol/L in men or ≥ 357 μmol/L in women. The primary study endpoint was a composite of major adverse cardiovascular events (MACE), including all-cause death, nonfatal MI, nonfatal stroke, revascularization, and hospitalization for unstable angina or heart failure. Kaplan–Meier, Cox regression, and receiver-operating characteristic analyses were performed.

Results

Patients with HUA (prevalence of 23.5%) had a significantly higher incidence of MACE (18.7% vs. 12.8%; p = 0.015) than patients without during the median follow-up of 41.7 months. HUA was closely associated with an increased risk of MACE even after multivariable adjustment (hazard ratio 1.498, 95% confidence interval: 1.080 to 2.077; p = 0.016). HUA remained a robust risk factor of MACE after propensity score matching analysis. Moreover, HUA showed an area under the curve (AUC) of 0.59 for predicting MACE. Incorporation of HUA to the thrombolysis in myocardial infarction (TIMI) score yielded a significant improvement in discrimination for MACE.

Conclusions

HUA was independently associated with poor prognosis after MINOCA. Routine assessment of HUA may facilitate risk stratification in this specific population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00636-2.

Serum uric acid is an independent risk factor of worse mid- and long-term outcomes in patients with non-ST-segment elevation acute coronary syndromes

BACKGROUND

The data on the association between serum uric acid (sUA) concentration and outcomes in patients with an ACS are inconsistent and do not focus on patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS). The aim of this study was to analyze an association of sUA concentration on admission and outcomes in those patients.

METHODS

Data from the prospective, single-center registry of patients hospitalized due to NSTE-ACS from January 2006 to December 2016 were analyzed retrospectively. The population was divided into quartiles according to the baseline sUA. The primary outcome was the incidence of all-cause death, non-fatal myocardial infarction, stroke and ACS-driven revascularization at 36 months.

RESULTS

Total of 2,824 patients with sUA measured on admission were included in this analysis with a median sUA of 352 µmol/L (5.92 mg/dL). Patients with higher sUA were older and more burdened with cardiovascular risk factors and history of coronary events. The prevalence of multivessel coronary artery disease and left main stenosis was significantly higher in patients with higher sUA. Elevated sUA concentration was associated with significantly worse short-, mid- and long-term outcomes. All-cause mortality was significantly higher in each analyzed period. In the multivariable analysis, sUA elevation was identified as an independent predictor of all-cause mortality at 12-month and 36-month follow-up.

CONCLUSIONS

Elevated baseline sUA concentration was independently associated with worse mid- and long-term outcomes in patients with NSTE-ACS. Baseline sUA concentration could identify patients with NSTE-ACS at higher risk of more dismal prognosis.

Potential Therapeutic Benefits of Sodium-Glucose Cotransporter 2 Inhibitors in the Context of Ischemic Heart Failure: A State-Of-The-Art Review

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of anti-diabetic agents that block the reabsorption of glucose in the proximal convoluted tubule of the nephron, thereby contributing to glycosuria and lowering blood glucose levels. SGLT2 inhibitors have been associated with improved cardiovascular outcomes in patients with diabetes, including a reduced risk of cardiovascular death and hospitalizations for heart failure. Recently, DAPA-HF and EMPEROR REDUCED trials showed the beneficial cardiovascular effect of SGLT2 inhibitors in patients with heart failure with consistently reduced ejection fraction (HFrEF) regardless of the presence of diabetes. Moreover, some exploratory studies suggested that these drugs improve Left Ventricular (LV) systolic function and oppose LV adverse remodeling in patients with HFrEF. However, the exact mechanisms that mediated for this benefit are not fully understood. Beyond glycemic control, enhanced natriuresis, increased erythropoiesis, improved endothelial function, changes in myocardial metabolism, anti-inflammatory and anti-oxidative properties may all play an active role in SGLT2 inhibitors' cardiovascular benefits. A deep understanding of the pathophysiological interplay is key to define which HF phenotype could benefit more from SGLT2 inhibitors. Current clinical evidence on the comparison of different HF etiologies is limited to posthoc subgroup analysis of DAPA-HF and EMPEROR-REDUCED, which showed similar outcomes in patients with or without ischemic HF. On the other hand, in earlier studies of patients suffering from diabetes, rates of classic ischemic endpoints, such as myocardial infarction, stroke or coronary revascularization, did not differ between patients treated with SGLT2 inhibitors or placebo. The aim of this review is to discuss whether SGLT2 inhibitors may improve prognosis in patients with ischemic HF, not only in terms of reducing re-hospitalizations and improving left ventricular function but also by limiting coronary artery disease progression and ischemic burden.

The biology of urate

Urate is the end-product of the purine metabolism in humans. The dominant source of urate is endogenous purines and the remainder comes through diet. Approximately two thirds of urate is eliminated via the kidney with the rest excreted in the feces. While the transporter BCRP, encoded by ABCG2, has been found to play a role in both the gut and kidney, SLC22A12 and SLC2A9 encoding URAT1 and GLUT9, respectively, are the two transporters best characterized. Only 8-12% of the filtered urate is excreted by the kidney. Renal elimination of urate depends substantially on specific transporters, including URAT1, GLUT9 and BCRP. Studies that have assessed the biologic effects of urate have produced highly variable results. Although there is a suggestion that urate may have anti-oxidant properties in some circumstances, the majority of evidence indicates that urate is pro-inflammatory. Hyperuricemia can result in the formation of monosodium urate (MSU) crystals that may be recognized as danger signals by the immune system. This immune response results in the activation of the NLRP3 inflammasome and ultimately in the production and release of interleukin-1β, and IL-18, that mediate both inflammation, pyroptotic cell death, and necroinflammation. It has also been demonstrated that soluble urate mediates effects on the kidney to induce hypertension and can induce long term epigenetic reprogramming in myeloid cells to induce "trained immunity." Together, these sequelae of urate are thought to mediate most of the physiological effects of hyperuricemia and gout, illustrating this biologically active molecule is more than just an "end-product" of purine metabolism.

Prevalence and Risk Factors Associated with Hyperuricemia in the Pearl River Delta, Guangdong Province, China

Background

In China, the prevalence of HUA in the Pearl River Delta (PRD) region of Guangdong Province has not been extensively investigated. Therefore, this study investigated the prevalence of HUA and its related factors among people aged 20–99 years in nine cities in the PRD.

Materials and Methods

We selected 6491 health check participants from 9 cities in the PRD and collected participants’ anthropometric and biochemical test results for a cross-sectional study. We included 6491 participants and assessed their blood pressure (BP), body mass index (BMI), total cholesterol (TC), triglycerides (TG), glucose (Glu) and serum uric acid (UA) to analyze the regional prevalence of HUA and its related factors. HUA was indicated when fasting serum UA level was >420 μmol/L in men and >360 μmol/L in women.

Results

Overall prevalence of HUA in our cohort was 34.05%; prevalence was higher in men than in women (41.53% vs 26.14%, P < 0.001). Characteristics associated with HUA were hypertension (odds ratio (OR), 5.506; 95% confidence interval (CI), 4.402–6.889), higher body mass index (BMI; OR: 1.746; 95% CI: 1.560–1.954), age 31–40 years (OR: 0.829; 95% CI: 0.706–0.973), age 61–70 years (OR: 1.434; 95% CI: 1.194–1.722) and age ≥71 years (OR: 1.742; 95% CI: 1.397–2.173). In all subjects, serum UA was positively correlated with Glu, TG and TC. After we adjusted for age, BMI and BP, multivariate logistic regression analysis showed that HUA risk factors were high TC (OR: 1.770; 95% CI: 1.459–2.147) and TG (OR: 1.961; 95% CI: 1.632–2.357) in men; and high Glu (OR: 1.508; 95% CI: 1.084–2.099), TC (OR: 1.341; 95% CI: 1.084–1.660) and TG (OR: 1.680; 95% CI: 1.290–2.187) in women.

Conclusion

The prevalence of HUA was relatively high in the PRD of Guangdong Province. Relevant governmental bodies should focus on early diagnosis, early treatment and early intervention.

Tissue xanthine oxidoreductase activity in a mouse model of aristolochic acid nephropathy

Xanthine oxidoreductase (XOR) is a critical enzyme in purine metabolism and uric acid production, and its levels are reported to increase during stress, thereby promoting organ damage. Herein, we investigated the activity of XOR in a mouse model of aristolochic acid I (AA)-induced nephropathy, a type of nephrotoxic chronic kidney disease (CKD). A persistent decrease in renal function was observed in mice up to 4 weeks after 4 weeks of AA (2.5 mg kg^-1 ) administration. Renal histology revealed an increase in tubular interstitial fibrosis over time. Although AA administration did not change XOR activity in the plasma, heart, liver, or muscle, XOR activity was persistently increased in renal tissue. Our results suggest that the renal tissue-specific increase in XOR activity is involved in the progression of tubulo-interstitial disorders, specifically fibrosis.

A convenient sampling and noninvasive dried spot method of uric acid in human saliva: Comparison of serum uric acid value and salivary uric acid in healthy volunteers and hyperuricemia patients

Concentration of uric acid (UA) in serum is one of the markers used to diagnose gout and hyperuricemia. However, serum treatment and storage are cumbersome, and wounds are susceptible to infection. Therefore, a new sampling and analysis method using noninvasive biological samples has been developed, called the dried spot method of UA in human saliva (DSM-UHS). Saliva (5 μL) was dropped on filter paper (a spot with a diameter of 5 mm) containing hypoxanthine (IS) (5 μL) and dried at room temperature for 30 min. The filter paper was immersed in 200 μL of lithium carbonate solution and shaken in a block bath shaker for 5 min at 30 °C. Afterward, the extraction was concentrated and reconstituted with 100 μL of lithium carbonate solution analyzed by HPLC-UV. When comparing the concentration of UA in the human saliva of hyperuricemia patients (HPs) and with that of healthy volunteers (HVs), we observed the concentration of UA was higher in the HPs than in the HVs (p < 0.0001). In addition, the results showed a significant linear relationship between the content of UA in saliva and the content of UA in the serum (r = 0.6243). The content of UA in human saliva could indirectly reflect the content of UA in human serum. Then DSM-UHS could be used to determine the content of UA in the saliva of HVs and HPs. This study provides a new research method and strategy for the determination of human UA content and the clinical prewiring of hyperuricemia.

Role of comorbidities in heart failure prognosis Part 2: Chronic kidney disease, elevated serum uric acid

Despite improvements in pharmacotherapy, morbidity and mortality rates in community-based populations with chronic heart failure still remain high. The increase in medical complexity among patients with heart failure may be reflected by an increase in concomitant non-cardiovascular comorbidities, which are recognized as independent prognostic factors in this population. Heart failure and chronic kidney disease share many risk factors, and often coexist. The presence of kidney failure is associated with incremented risk of cardiovascular and non-cardiovascular mortality in heart failure patients. Chronic kidney disease is also linked with underutilization of evidence-based heart failure therapy that may reduce morbidity and mortality. More targeted therapies would be important to improve the prognosis of patients with these diseases. In recent years, serum uric acid as a determinant of cardiovascular risk has gained interest. Epidemiological, experimental and clinical data show that patients with hyperuricaemia are at increased risk of cardiac, renal and vascular damage and cardiovascular events. Moreover, elevated serum uric acid predicts worse outcome in both acute and chronic heart failure. While studies have raised the possibility of preventing heart failure through the use of uric acid lowering agents, the literature is still inconclusive on whether the reduction in uric acid will result in a measurable clinical benefit. Available evidences suggest that chronic kidney disease and elevated uric acid could worsen heart failure patients' prognosis. The aim of this review is to analyse a possible utilization of these comorbidities in risk stratification and as a therapeutic target to get a prognostic improvement in heart failure patients.

Impact of admission serum acid uric levels on in-hospital outcomes in patients with acute coronary syndrome

BACKGROUND

To assess the association between admission serum uric acid (SUA) levels and in-hospital outcomes in a real-world patients population with acute coronary syndrome (ACS) and to investigate the potential incremental prognostic value of SUA added to GRACE score (GRACE-SUA score).

METHODS

The data of consecutive ACS patients admitted to Coronary Care Unit of San Paolo and Niguarda hospitals in Milan (Italy) were retrospectively analyzed.

RESULTS

1088 patients (24% female) were enrolled. Mean age was 68 years (IQR 60-78). STEMI and NSTE-ACS patients were 504 (46%) and 584 (54%) respectively. SUA (OR 1.72 95%CI 1.33-2.22, p < 0.0001) and GRACE score (OR 1.04 95%CI 1.02-1.06, p < 0.0001) were significantly associated with an increased risk of in-hospital death at the multivariate analysis. Admission values of SUA were stratified in four quartiles. Rates of acute kidney injury, implantation of intra-aortic balloon pump and non-invasive ventilation use were significantly higher in the last quartile compared to Q1, Q2 and Q3 (p < 0.01). The areas under the ROC curve (AUC) for GRACE score and for SUA were 0.91 (95% CI 0.89-0.93, p < 0.0001) and 0.79 (95% CI 0.76-0.81, p < 0.0001) respectively. The AUC was larger for predicting in-hospital mortality with the GRACE-SUA score (0.94; 95% CI 0.93-0.95).

CONCLUSIONS

High admission levels of SUA are independently associated with in-hospital adverse outcomes and mortality in a contemporary population of ACS patients. The inclusion of SUA to GRACE risk score seems to lead to a more accurate prediction of in-hospital mortality in this study population.

Sialometric and Sialochemical Analysis in Individuals With Pulp Stones

The aim of this study was to analyze the saliva of patients with pulp stones, with sialometric and sialochemical tests. Eighty individuals, aged between18 and 65 years, of both sexes, were investigated. Patients were included in the pulp stone group when radiographic examination was suggestive of pulp stones in at least one permanent tooth, whereas those without this alteration were considered controls. Saliva was collected by stimulation, followed by salivary flowrate (SFR) and pH analysis tests. The organic components, such as urea (URE), glucose (GLU), total proteins (TPTs), alkaline phosphatase, creatinine (CRE), salivary amylase (SAM), and uric acid (URA), and the inorganic components, such as calcium, iron, and phosphorus, were evaluated by colorimetric techniques in an ultraviolet–visible (UV–vis) spectrophotometer. Differences among pulp stones and control groups were compared using Student’s t-test, with a significance level of p < 0.05. In both groups prevailed the female. Statistically significant differences between groups were observed for pH (p = 0.027), SFR (p = 0.002), alkaline phosphatase (p = 0.008), and URA (p = 0.005). None of the inorganic components showed significant difference (p > 0.05). In the analyses stratified by sex, difference between groups was observed for pH (p = 0.007) and URA (p = 0.003) in women. In conclusion, sialometric and sialochemical alterations occurred in patients with pulp stones, with significantly higher levels of pH, SFR, alkaline phosphatase, and URA.

Association Between Uric Acid and N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Unstable Angina Pectoris

BACKGROUND

The association between uric acid and N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) in patients with unstable angina pectoris (UAP) is unclear.

METHODS

We recruited 260 patients with UAP admitted to the first affiliated Hospital of Guangxi Medical University from February 2018 to August 2018. According to the level of uric acid, patients were divided into 4 groups (Q1 = 48.00-305.00 μmol/L; Q2 = 310.00-405.00 μmol/L; Q3 = 408.00-513.00 μmol/L; Q4 = 514.00-4330.00 μmol/L). The differences of NT-proBNP between groups and the relationship with cardiac function were compared.

RESULTS

The average age of the 260 patients enrolled was 75.04 years. The NT-proBNP of the 4 groups showed an increasing trend, and there were significant differences between the 4 groups (<0.001). On the other hand, with the increase of cardiac function (New York Heart Association), the levels of NT-proBNP and uric acid also showed an upward trend (all P < 0.05). Pearson correlation analysis showed that there was a positive correlation between uric acid log10 transform and NT-proBNP log10 transform (r = 0.272, P < 0.001). After adjusting the potential confounding factors, elevated uric acid was still significantly related to the increase of NT-proBNP (Q2 versus [vs.] Q1: OR = 469.64, 95%CI -1396.77 to 2336.05; Q3 vs. Q1: OR = 1166.53, 95%CI -726.12 to 3059.18; Q4 vs. Q1: OR = 3204.78, 95%CI 1240.86-5168.70). In subgroup analysis, the relationship between uric acid and NT-proBNP was significant in males, but no difference was observed in females.

CONCLUSIONS

In male patients with UAP, elevated uric acid is related to the increase of NT-proBNP, but this phenomenon is not obvious in female patients.

Serum uric acid level and subclinical left ventricular dysfunction: a community-based cohort study

AIMS

Although serum uric acid (SUA) level is correlated with oxidative stress and serves as a marker of poor prognosis in heart failure patients, its possible association with subclinical left ventricular (LV) dysfunction has not been evaluated. This study aimed to investigate the association between SUA and subclinical LV dysfunction in a sample of a general population without overt cardiac disease.

METHODS AND RESULTS

We examined 1175 participants who underwent extensive cardiovascular health check-up including laboratory tests and speckle-tracking echocardiography to assess LV global longitudinal strain (GLS). The association of SUA concentration, as a continuous variable and a categorical variable using quartiles, with the presence of abnormal LVGLS was assessed. Mean age was 62 ± 12 years, and 656 (56%) were male participants. Mean SUA was 5.6 ± 1.3 mg/dL (25th-75th percentile, 4.6-6.5 mg/dL). The prevalence of abnormal LVGLS (greater than -18.6%) was greatest in the upper quartile of SUA. In multivariable analysis, SUA as a continuous variable was significantly associated with abnormal LVGLS [adjusted odds ratio (OR), 1.26 per 1 mg/dL; P = 0.008] independent of traditional cardiovascular risk factors, pertinent laboratory parameters and echocardiographic measures, and medications. In the categorical analysis, the upper quartile of SUA was independently associated with abnormal LVGLS in a fully adjusted model (adjusted OR, 2.28 vs. lowest quartile; P = 0.020).

CONCLUSIONS

In a sample of the general population, an elevated SUA was independently associated with subclinical LV dysfunction. Assessment of LVGLS may add important prognostic information in individuals with elevated SUA, even in the absence of overt cardiac disease.

Association of gout with CAD and effect of antigout therapy on CVD risk among gout patients

Hyperuricemia has been identified as an independent risk factor for coronary artery disease (CAD), with a dose-response association. In this study, we explored the causal association between gout and antigout medication and the risk of incidental CAD. We sampled data from the National Health Insurance Research Database and recruited 37,091 patients as the gout cohort, and 37,091 controls. Our primary endpoint was the diagnosis of CAD during follow-up. The overall study population was followed up until CAD diagnosis, withdrawal from the National Health Insurance program, or the end of the study. Cox proportional hazards regression models were used to examine the effect of gout on the risk of CAD, represented by the HR with the 95% CI. Patients with gout were at greater risk of CAD, compared with those without gout: HR=1.49 after adjusting for potential confounders. Non-steroidal anti-inflammatory drugs and prednisolone use was associated with a reduced risk of CAD: HR=0.63 and 0.50, respectively. Patients with gout, treated with antigout medication, exhibited a reduced risk of CAD compared with non-gout patients. Among patients with gout, those on antigout therapy had 32% lower risk compared with those not on antigout therapy: adjusted HR=0.68, 95% CI 0.63 to 0.73. Gout increases the risk of CAD, and the use of antigout medication reduces CAD risk. These results indicate that gout or hyperuricemia is a modifiable risk factor for CAD.

Implications of Hyperuricemia in Severe Coronary Artery Disease

Hyperuricemia has been associated with mortality in patients with coronary artery disease (CAD). However, its prognostic value remains unknown in the context of severe CAD with heavy atherosclerotic burden in all 3 vessels. We used data from a large cohort of consecutive patients with severe CAD. The primary end point was all-cause death. Propensity score matching was used to identify 2 cohorts of patients with similar baseline characteristics. A total of 8,529 patients with available serum uric acid data were included in the study. Hyperuricemia was present in 1,207 (14.2%) patients. At baseline, hyperuricemic patients had more co-morbidities, and more often received medical therapy alone. During the median follow-up of 7.5 years, significantly more deaths occurred in hyperuricemic patients compared with normouricemic patients (22.5% vs 13.7%; p < 0.001). Multivariable analyses showed that hyperuricemia was associated with an increased risk of mortality (hazard ratio 1.33; 95% confidence interval 1.15 to 1.53; p < 0.001). Propensity score matching yielded similar results (hazard ratio 1.33; 95% confidence interval 1.11 to 1.61; p = 0.003). The association was relatively consistent across subgroups, except for an interaction between age and hyperuricemia. Addition of uric acid to SYNTAX score II provided significant improvements of reclassification and discrimination for mortality prediction. In conclusion, hyperuricemia is relatively common among patients with severe CAD and is independently associated with mortality. Moreover, uric acid can improve the predictability of a well-established risk score.

Femoral Intima-media Thickness, Risk Factors, and Markers of Inflammation in Cardiovascular Disease

Introduction: The burden of coronary artery disease (CAD) and peripheral vascular pathologies caused by atherosclerosis is constantly increasing. There is continuous research aiming to develop new methods that can evaluate the extent of atherosclerotic disease in different vascular beds, thus estimating global risk. Similar to carotid artery thickness, which is an established marker for increased cardiovascular risk and cerebrovascular disease, femoral intima-media thickness (f-IMT) may have the same role in case of peripheral arterial involvement. The aim of the study was determine whether f-IMT, determined at the level of the superficial femoral artery, is related to traditional risk factors, markers of peripheral vascular atherosclerosis and inflammation.

Material and methods: Forty-six patients with known cardiovascular disease were included in the study. Demographical data, cardiovascular history, and risk factors were assessed. We determined metabolic parameters (uric acid, fasting glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides), renal function (creatinine and GFR), and inflammation status for all patients. Each patient underwent ultrasound examination of the superficial femoral artery, by which f-IMT was determined for right and left limbs. Ankle-brachial index was also calculated. Data from the low (f-IMT <0.75 mm) and high (f-IMT >0.75 mm) f-IMT groups were compared and correlation coefficients were determined in each groups for f-IMT in relation to the other parameters.

Results: Mean age was 71.08 ± 9.78 years. 86.95% of the patients suffered from hyper-tension, 56.62% had coronary heart disease, and 21.73% had a history of stroke. More females had history of hypertension and CAD. The most prevalent cardiovascular risk factors were dyslipidemia (68.86%), diabetes (21.73%), and smoking (21.73%). There were significant differences between gender groups for total cholesterol levels (161.36 ± 25.04 mg/dL, 95%CI 150.26–172.47 in males vs. 201.33 ± 52.73 mg/dL, 95%CI 170.07–223.60 in females, p = 0.02), creatinine values (1.04 ± 0.22 mg/dL, 95%CI 0.94–1.14 for males vs. 0.91 ± 0.23 mg/dL, 95%CI 0.81–1.00 for females, p = 0.018), and left f-IMT (0.87 ± 0.18 mm, 95%CI 0.79–0.95 for males vs. 0.75 ± 0.10 mm, 95%CI 0.70–0.79 for females, p = 0.0049). In the group with low f-IMT, a significant, reverse correlation was established between f-IMT, uric acid (r = −0.483, p = 0.042), and right ABI (r = −730, p = 0.0006). In the group with high f-IMT, age (r = 0.408, p = 0.031), fasting glucose (r = 0.407, p = 0.034), total cholesterol (r = 0.429, p = 0.02), HDL-cholesterol (r = −0.56, p = 0.0019), triglycerides (r = 0.45, p = 0.01), hs-CRP (r = 0.45, p = 0.01), and left ABI (r = −0.71, p <0.0001) showed a significant correlation to f-IMT.

Conclusions: Increased femoral intima-media thickness is related to age, cardiovascular risk factors, and markers of peripheral arterial disease. Patients with higher f-IMT have a more augmented inflammatory status. Based on these correlations, in patients with cardiovascular disease, f-IMT could become a marker for increased cardiovascular risk.

Serum Uric Acid as an Independent Risk Factor for the Presence and Severity of Early-Onset Coronary Artery Disease: A Case-Control Study

Serum uric acid (UA) is the final product of purine metabolism in humans. The present study is aimed at identifying the potential association between serum UA and early-onset coronary artery disease (EOCAD). The study population consisted of 1093 EOCAD patients aged ≤50 years, and 1117 age- and sex-matched apparently healthy people served as controls. The concentrations of UA were measured by uricase method. The severity of CAD was evaluated by Gensini score. The mean serum level of UA was 5.843 ± 1.479 mg/dl in EOCAD patients and 5.433 ± 1.529 mg/dl in controls. Serum UA levels were significantly higher in the EOCAD group than those in the control group (P < 0.001) and was an independent risk factor for EOCAD (OR = 1.100, 95% CI: 1.022–1.185). The early-onset myocardial infarction patients with 3-vessel disease had higher serum UA levels than those with 1- or 2-vessel disease. The serum UA levels of EOCAD patients with acute coronary syndrome were significantly higher than those with chronic coronary artery disease. EOCAD patients with hyperuricemia had higher Gensini scores than those without hyperuricemia. In addition, the serum UA levels were affected by drinking (P < 0.01) and were positively correlated with serum creatinine (r = 0.323) and weight (r = 0.327). Our results show that serum UA was an independent risk factor for EOCAD. The serum UA levels were associated with the presence and severity of EOCAD and suggested that UA may be involved in the progression of EOCAD.

Serum Uric Acid Could Differentiate Acute Myocardial Infarction and Unstable Angina Pectoris in Hyperuricemic Acute Coronary Syndrome Patients

Introduction:

Serum uric acid (SUA) is the final product of purine metabolism in humans.

Aim:

The present study aimed to identify a potential association between serum UA and cardiac troponin I (cTnI) levels and to find out whether uric acid could differentiate patients presenting with the acute myocardial infarction (AMI) and unstable angina pectoris (UAP) in hyperuricemic and normouricemic acute coronary syndrome (ACS) patients.

Methods:

Eighty ACS patients, aged 50-83 years, were enrolled in the study, 40 of them presenting with AMI and 40 with UAP. Frequency of patients with serum uric level over threshold for hyperuricemia was investigated and two groups of patients were formed such as hyperuricemic and normouricemic groups (A and B groups, respectively) independently of type of ACS. Those groups of patients were also subjected to cTnI measurement.

Results:

Levels of SUA are associated with the type of ACS in the hyperuricemic ACS patients (AMI versus UAP, 499(458-590), 425(400-447) mmol/L, p=0.007, respectively). Uric acid correlated significantly with cTnI, moderate positively in the group A (rho=0.358, p=0.038) and moderate negatively in the group B (r=-0.309, p=0.037) of ACS patients. Multiple logistic regression analysis revealed that cTnI and age were independently associated with the SUA levels in the group A of ACS patients.

Conclusions:

Serum uric acid differentiates AIM and UAP patients in hyperuricemic group of acute coronary syndrome. Therefore it can be used as nonspecific parameter for evaluation of the myocardial lesion extent only in hyperuricemic ACS patients. This is supported by finding that cTnI along with age predicts SUA level in hyperuricemic ACS patients.

Change gout: how to deal with this "silently-developing killer" in everyday clinical practice

BACKGROUND

Despite being regarded as an easily-treatable disease, gout diagnosis and management can be challenging.

REVIEW

This review discusses current issues in gout management and proposes some potential solutions. Gout diagnosis should be reached as early as possible and often requires specific tests, such as synovial fluid analysis or imaging techniques that are not available in most centers, leaving healthcare professionals to rely only on clinical presentations and their experience. In addition, gout management requires the evaluation of multiple aspects, such as monitoring of serum uric acid (sUA) level (which should be reduced to <6 mg/dL) to ensure adherence and efficacy of treatment, evaluation of patient's risk profile and comorbidities, and continuous assessments to manage clinical manifestations. An important premise in gout management is non-pharmacological intervention; however, pharmacological urate-lowering therapy is crucial for an optimal control of the disease. Available options include xanthine-oxidase inhibitors (XOI), targeting uric acid overproduction, and uricosuric agents which target the predominant cause of hyperuricemia (under-excretion). Among these, lesinurad is the novel uricosuric agent to be used in combination with XOI in patients with gout not adequately controlled with XOI alone, which can further contribute to the control of hyperuricemia in gout.

CONCLUSIONS

Multidisciplinary management is crucial for the diagnosis and treatment of gout, in order to ensure treatment continuity and improve management. This review, therefore, advises that educational activities for General Practitioners and specialists should be implemented to help raise awareness on gout diagnosis, monitoring, and treatment.

Biomarkers and Gene Polymorphisms in Members of Long- and Short-lived Families: A Longevity Study

Background

The influence of biomarkers in human lifespan has been investigated but with no clear results yet.

Materials and methods

Lipids, Uric Acid (UA), Adiponectin (ADIPOQ), Insulin-like Growth Factor (IGF-1), cholesteryl ester transfer protein (CETP) and angiotensin-converting enzyme (ACE) proteins, as well as CETP, ADIPOQ, insulin-like growth factor binding protein-3 (IGFBP3) and ACE-gene polymorphisms were evaluated in 149 Greek individuals. The Long-Lived Families (LON) (n=84) comprised of 3 generations: long-lived aged ≥90 years (P), offspring (FL1) and their grandchildren (FL2), while the Short-Lived Families (EAD) (n=65) where both parents died <75 years, comprised of 2 generations: middle-aged (FD1) and children (FD2).

Results

Serum CETP and IGF-1 levels were lower, whereas AdipoQ concentrations were higher in P compared with FL1 and FL2 members (CETP: p = 0.03 for both comparisons; IGF-1 p < 0.001 for both comparisons and ADIPOQ: p = 0.001 and p = 0.004, respectively). Furthermore, serum triglycerides, UA and glucose concentrations were higher in FD1 compared with FD2 subjects (p=0.001, 0.02 and ≤0.001, respectively). In FD2 and FL2, CETP levels were lower in individuals with B2B2 compared with B1B1 genotype (p=0.007). Additionally, ACE concentrations were higher in individuals with DD compared with II genotype in both Families (p=0.001). After adjustment for age and gender, CETP levels were lower in P and FL2 individuals with B2B2 compared with the B1B1 genotype (p=0.004 and 0.007, respectively).

Conclusion

Increase serum TGs, UA and GL concentrations were higher in the middle-aged individuals compared with their children in families independently of their lifespan. The serum adiponectin concentration was the highest in the oldest old individuals implying beneficial influence on lifespan. Independently of family's lifespan history, the youngest individuals with CETPB2B2 genotype, compared with individuals with CETPB1B1 genotypes, had lower serum CETP concentrations. The knowledge of the unfavourable gene(s)influencing human lifespan may be helpful in encouraging individuals to follow healthier lifestyle habits and better control their high-risk biomarkers.

The validity, stability, and utility of measuring uric acid in saliva

AIM

Serum uric acid (UA) is associated with many health conditions, including kidney, cardiovascular, and metabolic disorders. We examined the validity and stability of salivary UA as a noninvasive measure of serum UA.

MATERIALS & METHODS

Using serum and salivary UA data from healthy adults (n = 99), we examined the UA serum-saliva correlation, and UA associations with adiponectin and C-reactive protein. Using longitudinal data from young adults (n = 182), we examined salivary UA stability.

RESULTS

We found robust positive serum-saliva correlations for UA. UA and adiponectin were inversely related in serum and saliva. Salivary UA was relatively stable; 62-66% of variance could be attributed to a latent trait-like component.

CONCLUSION

Salivary UA may be an important biomarker indexing health and disease risk.

Hyperuricemia and severity of coronary artery disease: An observational study in adults 35 years of age and younger with acute coronary syndrome

BACKGROUND

Coronary artery disease (CAD) in adults ≤ 35 years of age is rare, but the incidence is on the rise and the risk factors for this age group are largely uncertain. Previous studies have shown that hyperuricemia (HUA) is an independent risk factor for CAD in the general population, whereas the role in adults ≤ 35 years of age with acute coronary syndrome (ACS) is unclear.

METHODS

Patients, 18-35 years of age, diagnosed with ACS for the first time at the documented institu- tion between January 2005 and December 2015, were enrolled in the current study. The severity of CAD was assessed by the Gensini score. Patients were divided into two groups according to the definition of HUA. The relationship between HUA and CAD severity was assessed based on multi-variate analysis.

RESULTS

Seven hundred seventy-one participants fulfilling the criteria were included in this study (mean age, 31.6 years; 94.4% male). HUA, which was defined as a serum uric acid level ≥ 7.0 mg/dL (420μmol/L) in males and ≥ 6.0 mg/dL (357 μmol/L) in females, accounted for 37% of the participants. Multivariate analysis identified that HUA is an independent risk factor of CAD severity, as assessed by the Gensini score, in very young adults with ACS (OR 8.28; 95% CI 1.96-14.59; p = 0.01), and the effect of HUA on CAD severity was second only to diabetes mellitus.

CONCLUSIONS

Hyperuricemia was shown to be an independent risk factor for CAD severity in young adults with ACS (18-35 years of age).

Evaluation of the Effectiveness of Xanthine Oxidoreductase Inhibitors on Haemodialysis Patients using a Marginal Structural Model

A lower serum uric acid (UA) level has been associated with a higher mortality rate in haemodialysis patients. We investigated the long-term confounding factors of UA and mortality, and fitted a marginal structural model (MSM) based on the causal effect of xanthine oxidoreductase inhibitors (XORi). In total, 2429 patients on regular dialysis from April 2013 to March 2016 were included, and divided into quintiles by serum UA with Kaplan Meier (KM) curves and log rank analysis. Baseline characteristics were evaluated for relationships with all-cause mortality and cardiovascular disease (CVD) using the Cox hazard model. The MSM was used to control for time-dependent confounders of the XORi treatment effect. KM curves indicated that patients in the highest UA quintile had better outcomes than those in the lowest UA quintile. UA was not correlated with all-cause mortality or CVD events in the Cox model; however, the hazard ratio (HR) for mortality was 0.96 for the baseline administration of XORi. The MSM analysis for the effect of XORi treatment on all-cause mortality revealed a HR of 0.24 (95% confidence interval: 0.15-0.38) in all cohorts. These results suggest that XORi improved all-cause mortality in end-stage renal disease, irrespective of the serum UA level.

Is gout a risk equivalent to diabetes for stroke and myocardial infarction? A retrospective claims database study

Background

Gout is a risk factor for cardiovascular disease, but associations with specific cardiovascular outcomes, myocardial infarction (MI), and stroke are unclear. Our objective in the present study was to assess whether gout is as strong a risk factor as diabetes mellitus (DM) for incident MI and incident stroke.

Methods

In this retrospective study, we used U.S. claims data from 2007 to 2010 that included a mix of private and public health plans. Four mutually exclusive cohorts were identified: (1) DM only, (2) gout only, (3) gout and DM, and (4) neither gout nor DM. Outcomes were acute MI or stroke with hospitalization. We compared the age- and sex-specific rates of incident MI and stroke across the four cohorts and assessed multivariable-adjusted HRs.

Results

In this study, 232,592 patients had DM, 71,755 had gout, 23,261 had both, and 1,010,893 had neither. The incidence of acute MI was lowest in patients with neither gout nor DM, followed by patients with gout alone, DM alone, and both. Among men >80 years of age, the respective rates/1000 person-years were 14.6, 25.4, 27.7, and 37.4. Similar trends were noted for stroke and in women. Compared with DM only, gout was associated with a significantly lower adjusted HR of incident MI (HR 0.81, 95% CI 0.76–0.87) but a similar risk of stroke (HR 1.02, 95% CI 0.95–1.10). Compared with patients with DM only, patients with both gout and DM had higher HRs for incident MI and stroke (respectively, HR 1.35, 95% CI 1.25–1.47; HR 1.42, 95% CI 1.29–1.56).

Conclusions

Gout is a risk equivalent to DM for incident stroke but not for incident MI. Having both gout and DM confers incremental risk compared with DM alone for both incident MI and stroke.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1427-5) contains supplementary material, which is available to authorized users.

Analysis of traditional and emerging risk factors in premenopausal women with coronary artery disease: A pilot-scale study from North India

Premenopausal women are known to have less heart disease than their menopausal counterparts and men. However, there is a rising prevalence of coronary artery disease (CAD) in premenopausal females, which necessitates determination of risk factors that negate the effects of hormonal protection. There are few studies describing the prevalence of traditional and emerging risk factors in premenopausal women with CAD. Thus, our objective was to explore the prevalence of traditional and emerging risk factors and features of coronary lesions in premenopausal women with CAD in an Indian population. Forty premenopausal female patients with angiographically proven CAD and undergoing treatment with conventional therapies and 40 age-matched premenopausal females without any evidence of CAD were enrolled. Premenopausal females with CAD most commonly had the single-vessel CAD and the left anterior descending artery was most commonly involved. The prevalence of hypertension, diabetes, obesity, metabolic syndrome, family history of CAD and 10-year risk score was higher in premenopausal females with CAD than controls. Even after treatment with conventional therapies, premenopausal women with CAD had dyslipidemia and significantly elevated levels of emerging risk factors such as ApoB, ApoB/ApoA1 ratio, hsCRP, lipoprotein (a), uric acid, T4, fibrinogen, and total leukocyte count as compared to controls (p < 0.05). Further, they had significantly lower levels of HDL-C, and Apolipoprotein A1 and T3 which are protective markers for vascular risk. Multivariate regression analysis demonstrated that low levels of Apo A1 and high levels of fibrinogen, hsCRP and TG drive the vascular risk, and therefore these factors should be considered as candidates for better diagnosis, early detection, and intervention of CAD in premenopausal women.

Allopurinol use and the risk of acute cardiovascular events in patients with gout and diabetes

Background

Few studies, if any, have examined cardiovascular outcomes in patients with diabetes and gout. Both diabetes and gout are risk factors for cardiovascular disease. The objective of this study was to examine the effect of allopurinol on the risk of incident acute cardiovascular events in patients with gout and diabetes.

Methods

We used the 2007–2010 Multi-Payer Claims Database (MPCD) that linked health plan data from national commercial and governmental insurances, representing beneficiaries with United Healthcare, Medicare, or Medicaid coverage. In patients with gout and diabetes, we assessed the current allopurinol use, defined as a new filled prescription for allopurinol, as the main predictor of interest. Our outcome of interest was the occurrence of the first Incident hospitalized myocardial infarction (MI) or stroke (composite acute cardiovascular event), after which observations were censored. We employed multivariable-adjusted Cox proportional hazards models that simultaneously adjusted for patient demographics, cardiovascular risk factors and other medical comorbidities. We calculated hazard ratios [HR] (95% confidence intervals [CI]) for incident composite (MI or stroke) acute cardiovascular events. We performed sensitivity analyses that additionally adjusted for the presence of immune diseases and colchicine use, as potential confounders.

Results

There were 2,053,185 person days (5621.3 person years) of current allopurinol use and 1,671,583 person days (4576.5 person years) of prior allopurinol use. There were 158 incident MIs or strokes in current and 151 in prior allopurinol users, respectively. Compared to previous allopurinol users, current allopurinol users had significantly lower adjusted hazard of incident acute cardiovascular events (incident stroke or MI), with an HR of 0.67 (95% CI, 0.53, 0.84). Sensitivity analyses, additionally adjusted for immune diseases or colchicine use, confirmed this association.

Conclusions

Current allopurinol use protected against the occurrence of acute cardiovascular events in patients with gout and diabetes. The underlying mechanisms for this potential cardio-protective effect of allopurinol need further exploration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0513-6) contains supplementary material, which is available to authorized users.

Uric Acid for Cardiovascular Risk: Dr. Jekyll or Mr. Hide?

Uric acid (UA) is a potent endogenous antioxidant. However, high concentrations of this molecule have been associated with cardiovascular disease (CVD) and renal dysfunction, involving mechanisms that include oxidative stress, inflammatory processes, and endothelial injury. Experimental and in vitro results suggest that this biomarker behaves like other antioxidants, which can shift from the physiological antioxidant action to a pro-oxidizing effect according to their level and to microenvironment conditions. However, data on patients (general population or CAD cohorts) are controversial, so the debate on the role of hyperuricemia as a causative factor for CVD is still ongoing. Increasing evidence indicates UA as more meaningful to assess CVD in women, even though this aspect needs deeper investigation. It will be important to identify thresholds responsible for UA “biological shift” from protective to harmful effects in different pathological conditions, and according to possible gender-related differences. In any case, UA is a low-tech and inexpensive biomarker, generally performed at patient’s hospitalization and, therefore, easily accessible information for clinicians. For these reasons, UA might represent a useful additive tool as much as a CV risk marker. Thus, in view of available evidence, progressive UA elevation with levels higher than 6 mg/dL could be considered an “alarm” for increased CV risk.

The Association Between Hyperuricemia and Hematological Indicators in a Chinese Adult Population

The aim of this study was to explore the relationship between hyperuricemia and hematological indicators. Five hundred twenty-two male and 255 female subjects (18-90 years old) were recruited in the study. The level of serum uric acid (SUA), total white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin, hematocrit, and platelet count was measured, computed, and analyzed. Pearson correlation coefficients, Student t-tests, multivariate linear regression models, and multivariate logistic regression models were performed to analyze the results.For men, WBC count (r = 0.13, P < 0.01), RBC count (r = 0.15, P < 0.001), and hemoglobin (r = 0.11, P < 0.05) were significantly correlated with SUA. For women, WBC count (r = 0.24, P < 0.001), RBC count (r = 0.31, P < 0.001), hemoglobin (r = 0.31, P < 0.001), and hematocrit (r = 0.29, P < 0.001) were significantly correlated with SUA. For men, WBC (P < 0.01) and RBC (P < 0.05) counts were significantly higher in patients with hyperuricemia than in normal subjects. For men, after adjustment for confounding factors, those in the fourth quartiles of WBC counts had 1.66-fold increased odds of hyperuricemia as compared with those in the reference group. For women, after adjustment, those in the second to fourth quartiles of WBC count, RBC count, hemoglobin, and hematocrit had increased the odds of hyperuricemia as compared with those in the reference groups. Our study showed significant relations between the level of SUA and WBC count, RBC count, hemoglobin, and hematocrit, which could be important biological markers of hyperuricemia.