The association between serum uric acid level and coronary artery disease

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.

Elevated triglycerides and low triiodothyronine: Key risk factors for coronary artery calcification in patients with schizophrenia

OBJECTIVE

Coronary artery calcification (CAC) is a well-established independent predictor of coronary heart disease, and patients with schizophrenia have significantly higher rates compared to the general population. We performed this study to examine the population-specific risk factors associated with CAC in patients with schizophrenia.

METHODS

In this cross-sectional study, patients with schizophrenia who underwent low-dose chest CT scans between January 2020 and December 2021 were analyzed. Ordinary CAC scores and results of routine blood tests were obtained. Logistic regression was used to calculate the odds ratio (OR) for potential risk factors in patients with and without CAC, while the negative binomial additive model was used to explore the dose-response relationship between risk factors and CAC score.

RESULTS

Of the 916 patients, 233 (25.4 %) had CAC, while 683 (74.6 %) did not. After adjusting for confounding factors, higher triglyceride levels (OR = 1.20, 95 % confidence interval (CI): 1.04 to 1.38, p = 0.013) and low triiodothyronine levels (OR = 0.50, 95 % CI: 0.29 to 0.84; p = 0.010) were identified as risk factors for CAC. Both triglycerides (p = 0.021) and triiodothyronine (p = 0.010) were also found to have significant dose-response relationships with CAC scores according to the negative binomial additive model in the exploratory analysis.

CONCLUSIONS

This study highlights elevated serum triglycerides and decreased triiodothyronine levels as population-specific risk factors for CAC in patients with schizophrenia, suggest the need for close monitoring of CAC in patients with schizophrenia and further prospective trials to provide additional evidence on this topic.

Serum uric acid predicts the development of atherosclerosis in women but not in men: A ten-year cohort study in China

BACKGROUND AND AIM

Atherosclerosis is becoming a significant health burden. Serum uric acid (SUA) is the final enzymatic product of purine metabolism and can contribute to the development of atherosclerosis. The aim of this study was to explore the possible predictive value of SUA in the development of atherosclerosis in a healthy Chinese population.

METHODS AND RESULTS

In this study, a total of 11,222 healthy subjects with no carotid plaque at baseline were enrolled and divided into sex-specific groups, and then the occurrence of carotid plaque during the follow-up time was documented. The association between carotid plaque and SUA levels was examined using Cox proportional-hazards regression models. The mean SUA level was 5.35 ± 1.41 mg/dL. A total of 2,911 individuals (25.94%) developed carotid plaque during the follow-up time, including 1,071 females and 1,840 males. After adjusting for potential confounding factors, the hazard ratio (HR) and 95% confidence interval (95% CI) in women for the occurrence of carotid plaque associated with SUA levels were 1.163 (1.017-1.330), but no significant correlation was found in men, as the HR was 1.050 (0.965-1.143).

CONCLUSION

Our results indicate that SUA levels predict the development of carotid plaque independent of traditional risk factors only in women.

The Chinese patent medicine Tongfengding capsule for gout in adults: a systematic review of safety and effectiveness

BACKGROUND

Gout is a common inflammatory arthritis caused by increased serum uric acid levels. Untreated or insufficiently treated gout can lead to deposition of monosodium urate crystals in joints, cartilage, and kidneys. Although Tongfengding capsules, a Chinese patent medicine, have long been used to treat gout, their effects and safety have not been reviewed systematically. This study evaluated its efficacy and safety for gout in adults.

METHODS

Randomized controlled trials involving Tongfengding capsule for gout in adults were searched from PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CBM, CNKI, and VIP databases, and analyzed using the Cochrane Handbook criteria. The primary outcome measures were the total effective rate. The secondary outcome measures including the blood uric acid (BUA), 24-h urinary total protein (24-h UTP), blood urea nitrogen (BUN), interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α) and adverse effects. The risk of bias was evaluated in all included studies. RevMan ver. 5.3.5 and GRADE profiler was used for data analysis and assessing the quality of evidence, respectively.

RESULTS

Six studies (n = 607 Chinese participants) were included. Tongfengding capsules plus conventional treatment significantly increased the total effective rate (RR 1.21, 95% CI 1.11-1.33), while reducing the BUA (MD - 66.05 µmol/L, 95% CI - 81.26 to - 50.84), 24-h UTP (MD - 0.83 g/24 h, 95% CI - 0.96 to - 0.70), BUN (MD - 0.90 mmol/L, 95% CI - 1.60 to - 0.20), IL-6 (MD - 6.99 ng/L, 95% CI - 13.22 to - 0.75), IL-8 (MD - 12.17 ng/L, 95% CI - 18.07 to - 6.27), TNF-α (MD - 8.50 ng/L, 95% CI - 15.50 to - 1.51), and adverse effects (RR 0.21, 95% CI 0.04-0.95).

CONCLUSION

Tongfengding capsules plus conventional treatment is safe and beneficial for adults with gout compared with conventional treatment.

Correlation of elevated serum uric acid with coronary artery disease in Xinjiang, China: A retrospective case-control study

Elevated serum uric acid (SUA) levels are associated with coronary artery disease (CAD). However, whether this association is independent of traditional cardiovascular risk factors remains controversial. Our study aimed to determine the concentration of SUA in the presence and severity of CAD in multi-ethnic patients in Xinjiang, China. For this study, 412 consecutive patients with percutaneous coronary intervention (PCI) and 845 individuals with normal coronary angiograms were included in the study. CAD severity was evaluated using the Gensini score index. The SUA concentrations and the levels of various cardiometabolic risk factors were investigated. We assessed the relationship between SUA levels and other cardiometabolic risk factors. Logistic regression was used to evaluate risk factors for PCI patients. SUA levels were significantly elevated in PCI patients compared to those in control subjects (P < .01). With increased UA levels, we found that the risk factors for CAD increased. SUA concentration had a significant positive relationship with total cholesterol (P < .01), triglycerides (P < .01), low-density lipoprotein cholesterol (P < .01), and creatinine (P < .01) in both sexes. In the PCI group, there was no significant correlation between UA levels. SUA levels are not an independent risk factor for CAD. It can be concluded that in Xinjiang, China, SUA is related to multiple risk factors for CAD, but not related to the severity of CAD.

Mediating effect of metabolic diseases on the relationship between hyperuricemia and coronary heart disease

BACKGROUND AND AIMS

Studies have shown that elevated serum uric acid (SUA) may increase the risk of coronary heart disease (CHD). However, it is still disputable how mediate effects between metabolic diseases and hyperuricemia affect the incidence of CHD. This study aimed to explore whether metabolic diseases may mediate the connection from hyperuricemia at baseline to the elevated incidence risk of CHD during follow-ups.

METHODS AND RESULTS

Based on the Jinchang cohort, 48 001 subjects were followed for 9 years between June 2011 and December 2019. Multivariate-adjusted Cox regression models were applied to estimate hazard ratios (HRs) of CHD with 95% confidence intervals (CIs). Significantly increased risks of CHD were observed in hyperuricemia (HR:1.46, 95%CI:1.28, 1.67) when compared with normouricemia population. The mediating effect model further demonstrated that metabolic diseases could mediate the association between hyperuricemia and CHD pathogenesis, partially for the combined metabolic diseases with mediation effects of 45.12%, 25.24% for hypertension, 28.58% for overweight or obese status, 29.05% for hypertriglyceridemia, 6.70% for hypercholesterolemia, 3.52% for low high density lipoprotein cholesterol (HDL-C), and 6.51% for high low density lipoprotein cholesterol (LDL-C), respectively.

CONCLUSIONS

Hyperuricemia significantly increased the risk of incident CHD, and this association was partly mediated by metabolic diseases.

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

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

The Impact of Uric Acid and Hyperuricemia on Cardiovascular and Renal Systems

The description of gout dates back almost 5000 years, and scientific interest in uric acid increased when it was found to be involved in the pathogenesis of gout. Since then, many basic and clinical studies have assessed the implications of uric acid for the oxidative system, inflammation, and cardiovascular and renal outcomes. Uric acid-lowering therapy failed to improve clinical hard outcomes in asymptomatic hyperuricemia, and it is retained in symptomatic hyperuricemia. Dietary and lifestyle modifications are critical to manage hyperuricemia. More studies are warranted to investigate the role of uric acid-lowering drugs on cardiovascular outcomes.

Uric acid in chronic coronary syndromes: Relationship with coronary artery disease severity and left ventricular diastolic parameter

BACKGROUND AND AIMS

Uric Acid (UA) has been related to the development of Cardio-Vascular (CV) events in patients affected by Chronic Coronary Syndromes (CCS). Among various hypothesis, two arise: UA may negatively act on coronary artery determining a higher degree of atherosclerotic disease, and/or on heart determining a higher prevalence of diastolic dysfunction. Both the above hypothesized effects are object of our investigation.

METHODS AND RESULTS

231 patients who were admitted to the cardiological department of the Niguarda Hospital (Milan, Italy) for CCS from January 2017 to June 2018 were enrolled. Coronary atherosclerotic burden was evaluated from coronary angiography as the number and type of involved vessels, as well as with both Gensini and Syntax scores. All subjects underwent a complete echocardiogram. At unadjusted and adjusted/multivariable analysis, UA levels were not significantly associated with variables analysed from the coronary angiography (number and type of vessels involved, neither the Gensini and Syntax scores) as well as with echocardiographic parameters regarding systolic and diastolic function.

CONCLUSIONS

In conclusion, the main finding of our work is the absence of a role for UA in determining coronary arteries disease as well as LV diastolic dysfunction in CCS subjects. Taking together the results of previous studies with ours, we hypothesize that UA could act on heart (both on coronary arteries and on LV function) in an early phase of the disease, whereas while in the advanced stages other factors (previous myocardial infarction, previous myocardial revascularization and so on) may overshadow its effects.

External application of herbal medicine for gout: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Gout affects a significant portion of the population worldwide annually. Numerous studies have been reported mainly in East Asia, explaining the use of traditional herbal decoctions for gout treatment. Our systematic review will be conducted to critically evaluate the evidence for the safety and effectiveness of external applications of herbal medicines on gout.

METHODS

Two independent researchers will perform electronic literature searches, study selection, data extraction, and quality assessment. To identify randomized controlled trials (RCTs) involving various external applications of herbal medicine for gout, a search will be carried out using the following 7 electronic databases: MEDLINE, EMBASE, Cochrane Library, KoreaMed, Oriental Medicine Advanced Searching Integrated System, Korean Studies Information Service System, and China National Knowledge Infrastructure. Each electronic database will be searched for articles published from their inception to the present date. Studies will be selected based on predefined criteria and summarized data regarding study participants, interventions, control groups, outcome measures, side effects, and risk of bias. There are no restrictions on publication status or language. Studies that evaluated any type of external application of herbal medicines will be eligible for inclusion, and the primary outcome will be the blood uric acid level. The methodological quality of the included RCTs will be assessed using the Cochrane risk-of-bias tool.

RESULTS

The present study will evaluate effectiveness and safety of external application of herbal medicines for gout.

CONCLUSION

Our findings will establish evidence for the external application of herbal medicines for gout and will be informative for patients with gout, clinicians, policymakers, and researchers.The results of this systematic review will be published in a peer-reviewed journal and disseminated electronically and in print. This review will be updated to inform and guide healthcare practices.

Effects of Urate-Lowering Therapy on Risk of Hyperlipidemia in Gout by a Population-Based Cohort Study and on In Vitro Hepatic Lipogenesis-Related Gene Expression

Patients with gout are at a higher risk of cardiovascular disease, which is associated with hyperlipidemia. Management of gout in Taiwan is poor, and the association between urate-lowering therapy (ULT) among gout patients and hyperlipidemia is unclear. We conducted a retrospective cohort study using data from the Longitudinal Health Insurance Database (LHID) of Taiwan on new-onset gout patients and a comparison cohort without gout. A Cox proportional hazards model was used to analyze differences in the risk of hyperlipidemia between patients with and without gout after considering related comorbidities. We also examined the ULT medications on the hepatic expression of lipogenesis-related genes. After adjusting for potential confounders, the case group (44,413 patients) was found to have a higher risk of hyperlipidemia than the control cohort (177,652 patients) [adjusted hazards ratio (aHR) = 2.55]. Gout patients without antigout treatment had significantly higher risk of hyperlipidemia than the control cohort (aHR = 3.10). Among gout patients receiving ULT, except those receiving probenecid (aHR = 0.80), all had significantly lower risk of hyperlipidemia than gout patients without ULT (all aHR < 0.90). Using real-time polymerase chain reaction, we found that most of the antigout drugs decreased the expression of hepatic genes related to lipogenesis in differentiated HepaRG cells. These data indicate that these antigout drugs reduce hyperlipidemia in gout patients, partly via the reduction in expression of lipogenesis-related genes, leading to improved blood lipid profiles. We provide evidence of the strong association between gout and hyperlipidemia and highlight the need for appropriate treatment guidelines.

Investigation of serum ischemia-modified albumin levels in coronary artery disease patients

Objective

Ischemia-modified albumin (IMA) is a novel marker for the detection of ischemia. The value of this biomarker has been studied in patients with coronary artery disease (CAD). However, the relationship between the severity of coronary stenosis and serum IMA levels remains unknown. Therefore, we aimed to investigate the potential role of serum IMA levels in predicting the severity of coronary atherosclerosis.

Materials and methods

One hundred and forty-two individuals who underwent coronary angiography for coronary artery disease complaints were included in the study. Participants were divided into three groups based on their diagnosis as control (healthy subjects), group I (subjects with lower Gensini score), and group II (subjects with higher Gensini score). Global Registry of Acute Coronary Events (GRACE) risk score and Gensini scores were calculated after coronary angiogram in the patient groups. Then, venous blood samples were collected from each participant. Serum IMA levels and the levels of routine laboratory markers were measured.

Results

The serum lymphocyte, neutrophil, and high-density lipid (HDL) levels were statistically insignificant between the groups. The white blood cell (WBC) count and IMA levels were significantly higher in the patient groups (p < 0.05). The GRACE and Gensini scores were significantly different in the patient groups (p < 0.05). However, there was no significant correlation between the GRACE and Gensini scores and serum IMA levels.

Conclusion

Although IMA levels can be a significant predictor for ischemia according to previous reports, this biomarker seems to be insufficient for determining the severity of disease in patients with CAD.

Hyperuricaemia and gout in cardiovascular, metabolic and kidney disease

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

Hyperuricemia and Hypertension, Coronary Artery Disease, Kidney Disease: From Concept to Practice

Since the publication of the Framingham Heart Study, which suggested that uric acid should no longer be associated with coronary heart disease after additional adjustment for cardiovascular disease risk factors, the number of publications challenging this statement has dramatically increased. The aim of this paper was to review and discuss the most recent studies addressing the possible relation between sustained elevated serum uric acid levels and the onset or worsening of cardiovascular and renal diseases. Original studies involving American teenagers clearly showed that serum uric acid levels were directly correlated with systolic and diastolic pressures, which has been confirmed in adult cohorts revealing a 2.21-fold increased risk of hypertension. Several studies involving patients with coronary artery disease support a role for serum uric acid level as a marker and/or predictor for future cardiovascular mortality and long-term adverse events in patients with coronary artery disease. Retrospective analyses have shown an inverse relationship between serum uric acid levels and renal function, and even a mild hyperuricemia has been shown to be associated with chronic kidney disease in patients with type 2 diabetes. Interventional studies, although of small size, showed that uric acid (UA)-lowering therapies induced a reduction of blood pressure in teenagers and a protective effect on renal function. Taken together, these studies support a role for high serum uric acid levels (>6 mg/dL or 60 mg/L) in hypertension-associated morbidities and should bring awareness to physicians with regards to patients with chronic hyperuricemia.

Correlation between Gout and Coronary Heart Disease in Taiwan: A Nationwide Population-Based Cohort Study

Background

Gout is the most common inflammatory arthritis in adult males. Patients with gout are at a higher risk of coronary heart disease (CHD). This study aimed to investigate the correlation between gout and CHD.

Methods

This was a retrospective cohort study that used data from the Longitudinal Health Insurance Database of Taiwan. The study subjects were 46,140 patients with new-onset gout during 2003-2010. To avoid selection bias, we used propensity score matching. A Cox proportional hazard model was used to analyze differences in the risk of CHD between patients with and without gout after controlling for related variables.

Results

The patients with gout had a higher risk of CHD than the patients without gout [adjusted hazards ratio (HR) = 1.34, 95% confidence interval (CI): 1.23-1.45]. The risk of CHD increased with older age. Other related factors for CHD included gender (female vs. male, adjusted HR = 0.86, 95% CI: 0.79-0.93), hypertension (adjusted HR = 1.53, 95% CI: 1.42-1.65), hyperlipidemia (adjusted HR = 1.18, 95% CI: 1.07-1.29), and diabetes mellitus (adjusted HR = 1.24, 95% CI: 1.13-1.36).

Conclusions

We found correlations between gout and CHD and other influencing factors including hypertension, hyperlipidemia, and diabetes mellitus. We also found that gender and age were associated with CHD.

Evaluation of the association between hyperuricemia and coronary artery disease: A STROBE-compliant article

The aim of the study was to assess the independent contribution of hyperuricemia to coronary artery disease (CAD) confirmed by coronary angiography (CAG), and to explore associations between serum uric acid (SUA) level and CAD.We performed a retrospective cohort study of 5069 patients who underwent CAG. Patients were divided into groups: hyperuricemia (n = 1178) versus nonhyperuricemia (n = 3891) and CAD (n = 3433) versus non-CAD (n = 1636).The incidence of CAD was higher in the hyperuricemia group than in the nonhyperuricemia group (71.5% vs 66.6%, P = .002). Hyperuricemia and CAD were significantly correlated in women (odds ratio = 1.509, 95% confidence interval, 1.106-2.057, P = .009). And there were trends, higher SUA quartiles were associated with higher percentage of CAD (62.3%, 68.0%, 68.9%, and 71.7% for quartiles 1, 2, 3, and 4, respectively, P < .001), and the incidence of 3-vessel disease increased (25.2%, 26.4%, 27.2%, and 31.1% for quartiles 1, 2, 3, and 4, respectively, P = .001) and that of normal vessel decreased (37.7%, 32.0%, 31.1%, and 28.3% for quartiles 1, 2, 3, and 4, respectively, P < .001) across quartiles, these trends were found in female group, but not in male group. The SUA level significantly increased as the number of diseased vessels increased (P < .001).There was an independent correlation between hyperuricemia and CAD in women. A higher SUA level was associated with a higher incidence of 3-vessel disease in women.

Relation of Elevated Serum Uric Acid Level to Endothelial Dysfunction in Patients with Acute Coronary Syndrome

Aim: Serum uric acid (SUA) level is known to have a prognostic value in patients with acute coronary syndrome (ACS). Endothelial function plays an important role in the development of cardiovascular disease. Although relation between SUA level and endothelial function has been previously studied in various populations, it is partially understood in patients with ACS.

Methods: A total of 55 patients with ACS with measurements of SUA level and reactive hyperemia index (RHI) to evaluate endothelial function were included. They were classified into three groups according to the tertiles of SUA level. The tertiles of SUA level were as follows: low tertile, ≤ 5.2 mg/dl; intermediate tertile, 5.3 to 6.5 mg/dl; and high tertile, ≥ 6.6 mg/dl.

Results: Mean SUA level and RHI were 5.8 ± 1.5 mg/dl and 1.88 ± 0.58. There was a significant negative correlation between SUA level and RHI (r = −0.41, p = 0.002). RHI was stepwisely observed in favor of the higher tertile groups (2.14 ± 0.74 vs. 1.84 ± 0.45 vs. 1.67 ± 0.38, p = 0.04). Multivariate analysis showed elevated SUA level as an independent predictor of reduced RHI.

Conclusion: Elevated SUA level was significantly associated with endothelial dysfunction in patients with ACS, possibly leading to subsequent poor outcomes following ACS.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Correlation of Serum Uric Acid Levels with Nonculprit Plaque Instability in Patients with Acute Coronary Syndromes: A 3-Vessel Optical Coherence Tomography Study

Elevated serum uric acid (SUA) level is known to be a prognostic factor in patients with acute coronary syndrome (ACS). However, the correlation between SUA level and coronary plaque instability has not been fully evaluated. The aim of this study was to investigate the association between SUA level and plaque instability of nonculprit lesions in patients with ACS using optical coherence tomography. A total of 150 patients with ACS who underwent 3-vessel optical coherence tomography were selected. Patients were classified into 3 groups according to tertiles of SUA level. There was a trend towards a thinner fibrous cap (0.15 ± 0.06 versus 0.07 ± 0.01 versus 0.04 ± 0.01 mm², p < 0.001) and a wider mean lipid arc (169.41 ± 33.16 versus 177.22 ± 37.76 versus 222.43 ± 47.65°, p < 0.001) with increasing SUA tertile. The plaques of the high and intermediate tertile groups had a smaller minimum lumen area than the low tertile group (6.02 ± 1.11 versus 5.38 ± 1.28 mm², p < 0.001). In addition, thin-cap fibroatheromas, microvessels, macrophages, and cholesterol crystals were more frequent in the high tertile group than the low and intermediate groups. Multivariate analysis showed SUA level to be a predictor of plaque instability.

Risk factors for first-time acute myocardial infarction patients in Trinidad

Background

The relative importance of coronary artery disease (CAD) risk varies globally. The aim of this study was to determine CAD risk factors for acute myocardial infarction (AMI) among patients in public health care institutions in Trinidad using a case–control type study design.

Methods

The sample comprised 251 AMI patients hospitalized between March 1, 2011 and April 30, 2012 and 464 age- and sex-matched non-AMI patients with no terminal or life-threatening illness and who did not undergo treatment for CAD. SPSS version 19 was used for data analysis that included chi-square tests, unadjusted and adjusted odds ratios (OR) and conditional multiple binary logistic regression.

Results

There was no difference in age between AMI and non-AMI patients (p = 0.551). Chi-square test revealed that clinical and lifestyle variables including stressful life, diabetes, hypertension, hypercholesterolaemia, ischaemic heart disease (IHD), a family history of IHD (p ≤ 0.001), smoking (p = 0.007) and alcohol consumption (p = 0.013) were associated with AMI; sex (p = 0.441), ethnicity (p = 0.366), age group (p = 0.826) and renal failure (p = 0.487) were not.

Both unadjusted and adjusted (for age) ORs showed that the odds of hypertension, IHD and alcohol consumption were greater among AMI patients than among non-AMI patients for males; diabetes and IHD for females; and that the odds of a stressful life was greater among non-AMI patients and were the same for both groups with respect to sex, age > 45 years, hypercholesterolemia, renal insufficiency, and family history of IHD.

Conditional multiple logistic regression showed that smoking [OR: 0.274, p ≤ 0.001, 95% CI for OR (0.140, 0.537)], a stressful life [OR: 2.697, p ≤ 0.001, 95% CI for OR (1.585, 4.587)], diabetes [OR: 0.530, p = 0.020, 95% CI for OR (0.310, 0.905)], hypertension [OR: 0.48, p = 0.10. 95% CI for OR (0.275, 0.837)] and IHD [OR: 0.111, p ≤ 0.001, 95% CI for OR (0.057, 0.218)] were the only useful AMI predictors.

Conclusions

Smoking, diabetes, hypertension, IHD and decrease stress are useful AMI predictors.

An association of smoking with serum urate and gout: A health paradox

BACKGROUND

The potential effect of cigarette smoking on levels of serum urate and risk of gout has been considered by a large number of studies, either as the primary variable of interest or as a covariate.

METHODS

Here we systematically review the published evidence relating to the relationship of smoking with serum urate, hyperuricaemia, and gout.

RESULTS

Many studies have reported that smoking reduces serum urate, however, the evidence has not been conclusive with other studies pointing to the opposite or no effect. It has also been suggested that smoking reduces the risk of gout, although there is some evidence to contradict this finding.

CONCLUSION

A consensus has yet to be reached as to the effect of smoking on serum urate levels and the risk of gout.

The effects of hyperuricaemia on flow-mediated and nitroglycerin-mediated dilatation in high-risk patients

BACKGROUND AND AIMS

Uric acid is emerging as one of the newer risk markers to consider in the cardiovascular risk assessment because it is demonstrated to be associated with adverse cardiovascular outcomes, particularly in high cardiovascular risk patients. One of the proposed mechanisms involving hyperuricaemia is the development of vascular damage. The aim of this study is to examine the role of hyperuricaemia on vascular function in patients with high cardiovascular risk.

METHODS AND RESULTS

We examined the clinical significance of hyperuricaemia in relation to vasomotor response of the brachial artery by using high-resolution ultrasound in 304 subjects with coronary artery disease and/or diabetes. Nitroglycerin-mediated dilatation (NMD) was significantly lower in the hyperuricaemic group compared with the normouricaemic group (12.8 ± 6.9% vs. 16.2 ± 7.7%, p < 0.001), but no significant difference was observed in flow-mediated dilatation (FMD) between the two groups [3.78 (95% CR: 1.5-9.9) vs. 3.88 (95% CR: -2.6 to 9.9), p = 0.78]. Multivariate analysis demonstrated that smoking was the strongest predictor of FMD (b = -0.81, p = 0.02); and that smoking (b = -2.62, p = 0.003), SBP (b = -0.11, p = 0.001), hyperuricaemia (b = -2.11, p = 0.02) and use of nitrates (b = -3.30, p = 0.001) were independent predictors of NMD.

CONCLUSION

High cardiovascular risk patients with hyperuricaemia had a lower NMD than those with normouricaemia. Importantly, hyperuricaemia was independently associated with NMD after multivariable adjustments. To further understand the pathophysiological mechanisms involving hyperuricaemia, particularly in the context of impaired NMD, further experimental and clinical studies are needed.

A cross-sectional analysis of the relationship between uric acid and coronary atherosclerosis in patients with suspected coronary artery disease in China

Background

Although many studies have examined the relationship between uric acid (UA) and coronary artery disease (CAD), whether UA is an independent risk factor contributing to progression of CAD is still controversial. Whether UA plays a different role in different sexes is also unclear.

Methods

A total of 1116 individuals with suspected CAD were stratified into four groups according to their serum UA quartiles in total (men and women combined), in men, and in women. The association of UA with coronary atherosclerosis was assessed by univariable and multivariable logistic regression.

Results

In total and in women, the prevalence of any plaques and significant/severe stenosis was significantly increased with an increase in quartiles of UA (all P < 0.05). The proportion of triple-vessel disease and left main artery lesion was highest in the fourth quartile (both p < 0.05). Increasing quartiles of UA were significantly associated with a coronary artery calcium score (CACS) >10 (all P < 0.01). As UA levels increased in women, the incidence of double-vessel lesions (p = 0.017) and the proportion of mixed plaques (p = 0.022) were significantly increased. The proportion of a CACS of 0 in total, in men and women was highest in the first quartile (all P < 0.01). UA was the strongest predictor of significant stenosis, multivessel disease, and mixed plaques in women (all p < 0.05). UA was the only risk factor for mixed plaques in total (P = 0.046).

Conclusion

The level of UA was significantly associated with coronary atherosclerosis in women, but not men.

Systematic review and meta-analysis of the clinical efficacy and adverse effects of Chinese herbal decoction for the treatment of gout

BACKGROUND

In East Asia, numerous reports describe the utilization of traditional Chinese herbal decoctions to treat gout. However, the reported clinical effects vary.

OBJECTIVES

In this study, we reviewed and analyzed a large number of randomized controlled clinical trials to systematically assess the clinical efficacy and adverse reactions of Chinese herbal decoctions for treating gout.

METHODS

We performed a comprehensive search of databases, such as PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, Chinese biomedical literature database, et al. In addition, we manually searched the relevant meeting information in the library of the Third Military Medical University.

RESULTS

Finally, 17 randomized controlled trials with a sample size of 1,402 cases met the criteria and were included in the study. The results of the meta-analysis showed that when gout had progressed to the stage of acute arthritis, there was no significant difference in clinical efficacy between Chinese herbal decoctions and traditional Western medicine, as indicated based on the following parameters: serum uric acid (standardized mean difference (SMD):0.35, 95% confidence interval (CI): 0.03 to 0.67), C reactive protein (SMD: 0.25, 95% CI: -0.18 to 0.69), erythrocyte sedimentation rate (SMD: 0.21, 95% CI: -0.02 to 0.45) and overall clinical response (relative risk (RR): 1.05, 95% CI: 1.01 to 1.10). However, the Chinese herbal decoction was significantly better than traditional Western medicine in controlling adverse drug reactions (RR: 0.06, 95% CI: 0.03 to 0.13).

CONCLUSIONS

Through a systematic review of the clinical efficacy and safety of Chinese herbal decoctions and traditional Western medicine for the treatment of gout, we found that Chinese herbal decoction and traditional Western medicine led to similar clinical efficacy, but the Chinese herbal decoctions were superior to Western medicine in terms of controlling adverse drug reactions.

Relationship of serum uric Acid level and angiographic severity of coronary artery disease in male patients with acute coronary syndrome

Background and objective: The association between serum uric acid and ischemic heart disease remains controversial and it has not yet been established as cardiovascular risk factor. Our objective was to study the association of serum uric acid level with angiographic severity of coronary artery disease in men with acute coronary syndrome (ACS).

Methods: This cross-sectional study was conducted on 100 consecutive male patients presenting with ACS at Punjab Institute of Cardiology. Hyperuricemia was defined as serum uric acid level > 6.5 mg/dl. Severity of ischemic heart disease was assessed on the basis of Gensini score, number of diseased vessels, critical lesions and total occlusions on coronary angiogram.

Results: Mean age of normouricemic group (n=59) was 52.62 ± 9.46 years and mean age of hyperuricemic group (n=41) was 50.52 ± 9.40 years (p=0.273). Mean uric acid level; normouricemic group (4.75 ± 1.05), hyperuricemic group (7.61 ± 1.24), p<0.001. Mean Gensini score; normouricemic group (22.15 ± 21.52), hyperuricemic group (35.69 ± 26.80). Mann Whitney U test was applied to compare the Gensini score of two groups and it showed statistically significant difference (p value <0.006). Critical lesions, total occlusions and multi-vessel disease were more frequent in hyperuricemic group but statistically significant difference was found only for total occlusions (p=0.013) and critical lesions (p=0.046).

Conclusions: Hyeruricemia is associated with higher Gensini score and more frequent total occlusions and critical lesions in men presenting with acute coronary syndrome.

Effects of dapagliflozin on cardiovascular risk factors

People with diabetes are more likely to develop a cardiovascular (CV) disease compared with those without diabetes. Although effective glycemic control has been the focus of the management of type 2 diabetes mellitus (T2DM), it is also important to control other CV risk factors to improve outcomes in these patients. Dapagliflozin, a sodium-glucose co-transporter 2 inhibitor, lowers glucose levels in patients with T2DM by increasing urinary glucose excretion. Dapagliflozin therapy has been shown to impact a number of CV risk factors. Dapagliflozin improved glycemia with a low intrinsic propensity to cause hypoglycemia. Caloric loss associated with dapagliflozin-induced glucosuria also led to body weight reduction. Small changes from baseline in mean lipid parameters and reductions in serum uric acid levels were observed in patients taking dapagliflozin. Blood pressure reductions were also noted, consistent with modest drug-induced diuresis and weight loss. Furthermore, a lower rate of cardiac events was seen in patients taking dapagliflozin compared with those taking comparators in a meta-analysis of clinical trials on dapagliflozin. Overall, dapagliflozin has shown beneficial effects on CV risk factors in patients with T2DM. Further studies are underway to evaluate the effect of dapagliflozin on CV outcomes.

Association of plasma uric acid with ischaemic heart disease and blood pressure: mendelian randomisation analysis of two large cohorts

OBJECTIVES

To assess the associations between both uric acid levels and hyperuricaemia, with ischaemic heart disease and blood pressure, and to explore the potentially confounding role of body mass index.

DESIGN

Mendelian randomisation analysis, using variation at specific genes (SLC2A9 (rs7442295) as an instrument for uric acid; and FTO (rs9939609), MC4R (rs17782313), and TMEM18 (rs6548238) for body mass index).

SETTING

Two large, prospective cohort studies in Denmark.

PARTICIPANTS

We measured levels of uric acid and related covariables in 58,072 participants from the Copenhagen General Population Study and 10,602 from the Copenhagen City Heart Study, comprising 4890 and 2282 cases of ischaemic heart disease, respectively.

MAIN OUTCOME

Blood pressure and prospectively assessed ischaemic heart disease.

RESULTS

Estimates confirmed known observational associations between plasma uric acid and hyperuricaemia with risk of ischaemic heart disease and diastolic and systolic blood pressure. However, when using genotypic instruments for uric acid and hyperuricaemia, we saw no evidence for causal associations between uric acid, ischaemic heart disease, and blood pressure. We used genetic instruments to investigate body mass index as a potentially confounding factor in observational associations, and saw a causal effect on uric acid levels. Every four unit increase of body mass index saw a rise in uric acid of 0.03 mmol/L (95% confidence interval 0.02 to 0.04), and an increase in risk of hyperuricaemia of 7.5% (3.9% to 11.1%).

CONCLUSION

By contrast with observational findings, there is no strong evidence for causal associations between uric acid and ischaemic heart disease or blood pressure. However, evidence supports a causal effect between body mass index and uric acid level and hyperuricaemia. This finding strongly suggests body mass index as a confounder in observational associations, and suggests a role for elevated body mass index or obesity in the development of uric acid related conditions.

Relationship between uric acid and vascular structure and function in hypertensive patients and sex-related differences

BACKGROUND

We sought to analyze the relationship between uric acid (UA) and vascular structure and function based on the carotid intima-media thickness, the pulse-wave velocity (PWV), the central arterial pressure, and the augmentation index in hypertensive patients and to evaluate the sex-related differences.

METHODS

A cross-sectional study was performed with 366 hypertensive individuals aged 34-75 years (men = 61.74%). The vascular structure was assessed based on the carotid intima-media thickness, the arterial stiffness was assessed by PWV, and the vascular function was assessed using hemodynamic parameters such as the central and peripheral augmentation index and the ambulatory arterial stiffness index (AASI).

RESULTS

In the bivariable analysis, the PWV (r = 0.28; P < 0.01) and AASI (r = 0.25; P < 0.01) were positively correlated with UA in women. The central augmentation index (r = -0.16; P < 0.05) and peripheral augmentation index (r = -0.18; P < 0.05) were negatively correlated with UA, whereas the maximum carotid intima-media thickness (r = 0.11; P < 0.05) was positively correlated with UA in the global analysis. In the multiple linear regression analysis, a positive association between PWV and UA was observed after adjusting for classical risk factors (β = 0.27; P = 0.01) in women only. In turn, a negative association was observed between the AASI and UA after adjusting for confounders in men (β = -0.06; P = 0.04), with a positive association in women (β = 0.11; P = 0.03).

CONCLUSIONS

Serum UA showed a positive correlation with the mean maximum intima-media thickness and PWV, and this parameter showed a negative correlation with the central and peripheral augmentation indices, although this relationship was lost after adjusting for confounding factors. AASI showed a positive association in women and a negative association in men after adjusting for confounding factors.

CLINICAL TRIALS REGISTRATION

Clinical Trials.gov Identifier: NCT01325064.

Associations between serum uric acid and markers of subclinical atherosclerosis in young adults. The cardiovascular risk in Young Finns study

BACKGROUND AND METHODS

Serum uric acid (SUA) is a suggested biomarker for established coronary artery disease, but the role of SUA in early phases of atherosclerosis is controversial. The relations of SUA with vascular markers of subclinical atherosclerosis, including carotid artery intima-media thickness (cIMT), carotid plaque, carotid distensibility (Cdist) and brachial flow-mediated dilatation (FMD) were examined in 1985 young adults aged 30-45 years. In addition to ordinary regression, we used Mendelian randomization techniques to infer causal associations.

RESULTS

In women, the independent multivariate correlates of SUA included BMI, creatinine, alcohol use, triglycerides, glucose and adiponectin (inverse association) (Model R(2) = 0.30). In men, the correlates were BMI, creatinine, triglycerides, C-reactive protein, alcohol use, total cholesterol and adiponectin (inverse) (Model R(2) = 0.33). BMI alone explained most of the variation of SUA levels both in women and men (Partial R(2) ∼ 0.2). When SUA was modeled as an explanatory variable for vascular markers, it directly associated with cIMT and inversely with Cdist in age- and sex-adjusted analysis. After further adjustments for BMI or glomerular filtration rate, these relations were reduced to non-significance. No associations were found between SUA and FMD or the presence of a carotid plaque. Mendelian randomization analyses using known genetic variants for BMI and SUA confirmed that BMI is causally linked to SUA and that BMI is a significant confounder in the association between SUA and cIMT.

CONCLUSION

SUA is associated with cardiovascular risk markers in young adults, especially BMI, but we found no evidence that SUA would have an independent role in the pathophysiology of early atherosclerosis.

Mendelian randomization: application to cardiovascular disease

In the absence of an ethical, practical, and economical randomized trial, the epidemiologist is left to explore other methods in efforts to assert causality. An approach based on genotypic variation has the potential to mitigate against some of the problems found within conventional observational studies. Genetic variations associated with risk factors of interest at the population level can be used as proxy measures for these risk factors and to generate estimates of causal effect. The potential and the possible limitations of this approach within the cardiovascular field are presented in this review.

High Levels of Serum Uric Acid Predict Severity of Coronary Artery Disease in Patients with Acute Coronary Syndrome

We aimed to elucidate the relation between serum uric acid (SUA) level and severity of coronary artery disease (CAD) in nondiabetic, nonhypertensive patients (n = 246) with acute coronary syndrome (ACS). Severity of CAD was assessed by the Gensini score. One, 2, and 3 or more diseased vessels were identified in 87 (35.4%), 55 (22.4%), and 104 (42.2%) patients, respectively. Patients with hyperuricemia had higher Gensini score, high number of diseased vessels, critical lesions, and total occlusion. Serum uric acid level was significantly associated with number of diseased vessels. Serum uric acid was an independent risk factor for multivessel disease by univariate analysis. High levels of SUA associated with the severity of CAD in nondiabetic, nonhypertensive patients with ACS.

Perfluoroalkyl chemicals and elevated serum uric acid in US adults

Background:

Perfluoroalkyl chemicals, including perfluorooctanoic acid and perfluorooctane sulfonate, are man-made chemicals that have been detected in the blood of over 98% of the US population. Serum uric acid is a novel biomarker, even mild elevations of which has been implicated in the development of hypertension, diabetes mellitus, cardiovascular disease, and chronic kidney disease. We examined the relationship of serum perfluoroalkyl chemicals, including perfluorooctanoic acid and perfluorooctane sulfonate, and elevated uric acid levels in a representative sample of US adults.

Methods:

We examined 3883 participants from the 1999–2000 and 2003–2006 National Health and Nutritional Examination Surveys, a representative, multiethnic population-based survey of noninstitutionalized US adults. Serum perfluorooctanoic acid and perfluorooctane sulfonate were analyzed as quartiles. The main outcome was hyperuricemia.

Results:

We found that serum levels of perfluoroalkyl chemicals, including perfluorooctanoic acid and perfluorooctane sulfonate, were positively associated with hyperuricemia. This association appeared to be independent of confounders such as age, gender, race-ethnicity, body mass index, diabetes, hypertension, and serum cholesterol. Compared with subjects in quartile 1 (referent), the multivariate odds ratio for hyperuricemia among subjects in quartile 4 was 1.97 (95% confidence interval 1.44–2.70, P < 0.0001) for perfluorooctanoic acid and 1.48% (95% confidence interval 0.99–2.22, P = 0.0433) for perfluorooctane sulfonate. This observed association persisted in subgroup analysis by gender and body mass index.

Conclusion:

Our results demonstrate that elevated levels of perfluoroalkyl chemicals are associated with hyperuricemia even at low perfluoroalkyl chemical exposure levels as seen in the US general population.