Impact of diabetes on uric acid and its relationship with the extent of coronary artery disease and platelet aggregation: a single-centre cohort study

Hyperuricemia and the risk of stroke incidence and mortality: A systematic review and meta-analysis

Objectives

The relationship between hyperuricemia (HUA) and stroke remains controversial. In this systematic review, we discuss the association between HUA and stroke.

Materials and methods

The PubMed, Embase, Web of Science, and Cochrane Library were searched from their earliest records to March 13th, 2024, and additional papers were identified through a manual search. Prospective studies that provided a multivariate-adjusted estimate of the association between HUA and risk of stroke incidence and mortality, represented as relative risks (RRs) with 95% confidence intervals (CIs), were eligible.

Results

A total of 22 studies including 770,532 adults were eligible and included. Hyperuricemia was associated with a significantly increasing risk of both stroke incidence (pooled RR, 1.42; 95% CI, 1.31-1.53) and stroke mortality (pooled RR, 1.53; 95% CI, 1.18-1.99) in our meta-analyses. Relative risk of stroke incidence was as follows: females (pooled RR, 1.67; 95% CI, 1.44-1.92) and males (pooled RR, 1.13; 95% CI, 1.02-1.25). Relative risk of mortality was as follows: female (pooled RR, 1.41; 95% CI, 1.31-1.52) and males (pooled RR, 1.27; 95% CI, 1.20-1.34). For the risk of stroke mortality, the association between HUA and ischemic stroke (pooled RR, 1.39; 95% CI, 1.31-1.47) was more significant than that of hemorrhagic stroke (pooled RR, 1.13; 95% CI, 1.02-1.26).

Conclusion

Our study confirms an association between HUA and risk of stroke, which is more pronounced in females.

Prognostic Significance of Serum Uric Acid and Exercise Capacity in Older Adults Hospitalized for Worsening Cardiovascular Disease

Elevated serum uric acid (sUA) is associated with the risk of developing cardiovascular disease (CVD). Here, we examined the prognostic significance of sUA and exercise capacity in 411 Japanese adults (age, ≥65; mean, 81 years) hospitalized for worsening CVD. When the patients were stratified by sUA into three groups (<5.3, 5.4-6.9, >7.0 mg/dL), the high-sUA group had a significantly worse peak VO2 and composite endpoint (rehospitalization due to worsening CVD and all-cause mortality) compared with low- and moderate-sUA groups (p < 0.001). When the patients were stratified by sUA into five groups (sUA < 3.9, 4.0-5.9, 6.0-7.9, 8.0-8.9, and >10.0 mg/dL), the incidence of the composite endpoint was significantly higher in the highest sUA group compared with that in the reference group, but only in women. Univariate Cox regression analysis, but not a multivariate analysis, indicated that sUA was significantly associated with the composite endpoint. Although sUA and exercise capacity may have some degree of prognostic significance in older patients with CVD, this significance may differ between men and women.

Association of Serum Uric Acid With Retinal Capillary Plexus

BACKGROUND

To determine the association between serum uric acid (SUA) and the retinal capillary plexus (RCP) using optical coherence tomography angiography (OCTA).

METHODS

This cross-sectional study evaluated data from August 2019 to January 2020 from participants recruited from the Jidong community (Tangshan, Hebei, China). All participants completed detailed anthropometrical measurements, laboratory tests and comprehensive ophthalmic examinations. We assessed the vessel density in RCP using OCTA. We used multivariable analysis to evaluate the sex-specific association between SUA and RCP after adjusting for confounders.

RESULTS

A total of 2730 participants were included in this study. The mean age of the participants was 44.0 ± 11.6 years, and 1463 (53.6%) were women. The multivariable βs and 95% confidence intervals (CIs) of superficial RCP vessel density in the second through fourth SUA quartiles compared with the lowest SUA quartiles were -0.27 (-0.56 - 0.03), -0.30 (-0.60 - 0.01), and -0.46 (-0.78 - -0.14) (P for trend = 0.007) in men.

CONCLUSIONS

Higher SUA levels were significantly associated with lower RCP vessel density in men. Our findings provide evidence for the detrimental effect of high SUA levels on the retinal microvasculature and imply the importance of modulating SUA to prevent the microvascular alternation especially for men.

Carotid intima-media thickness in patients with hyperuricemia: a systematic review and meta-analysis

OBJECTIVE

Despite the high incidence and mortality of cardiovascular events in hyperuricemia patients, the role of serum uric acid in cardiovascular diseases is still controversial. The aim of this meta-analysis was to explore the difference of carotid intima-media thickness in hyperuricemia and control groups.

METHODS

We performed this meta-analysis by searching the PubMed, Cochrane Library, Embase and Web of Science databases up to July 2020. The 95% confidence intervals and standard mean differences were calculated to analyze the differences in carotid intima-media thickness in hyperuricemia groups and control groups. Sensitivity analysis, subgroup analysis and meta-regression were used to explore the sources of heterogeneity. Publication bias was evaluated by funnel plot and Begg's regression test. We used Stata 14.0 software to complete our analyses.

RESULTS

A total of 8 articles were included. The results showed that there was a significant increase in carotid intima-media thickness in the hyperuricemia groups compared with the control groups [SMD = 0.264, 95% CI (0.161-0.366), P < 0.001]. Subgroup analyses showed that age, sample size, blood pressure and body mass index were not the source of heterogeneity. Meta-regression enrolled the method of CIMT measurement, location, age, smoking and diabetes mellitus as categorical variables, but none of these factors was found to be significant in the model. The Begg's test value (P = 0.174) was greater than 0.05, indicating there was no publication bias.

CONCLUSION

The results showed that carotid intima-media thickness was increased in hyperuricemia patients compared with controls, which indicated that hyperuricemia patients may have a higher risk of cardiovascular diseases.

The Role of Uric Acid in Acute and Chronic Coronary Syndromes

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

Serum Uric Acid and Diabetes: From Pathophysiology to Cardiovascular Disease

Hyperuricemia, has been traditionally related to nephrolithiasis and gout. However, it has also been associated with the development of type 2 diabetes mellitus (T2DM) and cardiometabolic and cardiovascular diseases. Pathophysiologically, elevated serum uric acid (SUA) levels may be associated with abnormal lipid and glucose metabolism. In this narrative review, we consider the associations between hyperuricemia, hyperglycemia, atherosclerosis and thrombosis. Furthermore, we comment on the available evidence linking elevated SUA levels with the incidence and outcomes of coronary heart disease, stroke, peripheral artery disease and non-alcoholic fatty liver in subjects with T2DM. The effects of antidiabetic drugs (e.g. metformin, pioglitazone, sulfonylureas, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors and insulin) on SUA concentrations are also reviewed.

Low Serum Uric Acid Predicts Risk of a Composite Disease Endpoint

Background and objectives: Mortality may increase in hypouricemia as well as inhyperuricemia. We assessed the predictive value of low serum uric acid (SUA) levels on the risk of overall mortality or a composite endpoint of death and nonfatal events. Materials and Methods: In 1013 community-based middle-aged adults, free of uncontrolled diabetes and coronary heart disease at baseline, the association of sex-specific SUA tertiles with defined outcomes was evaluated prospectively by logistic regression, stratified to gender and presence of type-2 diabetes, using recent criteria. Results: Totally, 43 deaths and additional incident nonfatal events in 157 cases were recorded at a median 3.4 years' follow-up. Multivariable linear regression disclosed SUA to be significantly associated among non-diabetic individuals positively with creatinine, triglycerides, and body mass index in women further with fasted glucose. In multivariable-adjusted logistic regression analysis, sex-specifically dichotomized baseline uric acid (<5.1 and <4.1 mg/dL vs. higher values) significantly predicted the non-fatal events in the whole sample (relative risk (RR) 1.51 [95% confidence interval (CI) 1.02; 2.26]), as well as in men, while composite endpoint in the whole sample tended to rise (RR 1.38). Compared with the intermediate one, the top and bottom SUA tertiles combined tended to confer mortality risk (RR 2.40 [95% CI 0.89; 6.51]). Adverse outcomes in diabetic women were predicted by tertiles 2 and 3. Conclusions: Inverse association of SUA with adverse outcomes, especially in men, is consistent with the involvement of uric acid mass in autoimmune activation. The positive association of uric acid with adverse outcomes in diabetic women is likely mediated by concomitant high-density lipoprotein dysfunction.

Identification of two novel subgroups in patients with diabetes mellitus and their association with clinical outcomes: A two-step cluster analysis

Aims/Introduction

The aim of this study was to determine whether distinct subphenotypes of patients with type 2 diabetes in the European classification exist in Chinese populations, and to further establish novel subphenotypes more suitable for Chinese populations.

Material and Methods

The research retrospectively analyzed 5414 patients with type 2 diabetes from the National Clinical Research Center for Metabolic Diseases Diabetes Center in China, and a two‐step cluster analysis was carried out. First, we confirmed the European classification in Chinese populations by six parameters, including age at disease onset, body mass index, glycosylated hemoglobin, homeostatic model assessment 2 to estimate β‐cell function and insulin resistance, and glutamate decarboxylase antibodies. Furthermore, triglycerides and uric acid were added to refine the cluster analysis, and Cox regression was used to evaluate the risk of diabetic complications.

Results

Just three clusters were replicated in our cohort according to Emma Ahlqvist's European classification. When other variables were added to the cluster analysis, seven subgroups were identified, including five clusters of the European classification and two novel subgroups, namely, uric acid‐related diabetes and inheritance‐related diabetes. Compared with patients with inheritance‐related diabetes, patients with severe insulin‐resistant diabetes showed a higher risk of diabetic peripheral neuropathy, hypertension and chronic kidney disease, and the uric acid‐related diabetes subgroup showed a higher risk of coronary heart disease, cerebral vascular disease and end‐stage renal disease. Patients with severe insulin‐deficient diabetes showed a higher risk of diabetic retinopathy and diabetic foot than those with inheritance‐related diabetes. Furthermore, there were sex‐specific associations between subgroups and clinical outcomes. No significant difference was observed in the prevalence of cancer in each subgroup.

Conclusions

Seven subgroups of type 2 diabetes were identified in Chinese populations, with distinct characteristics and disparate clinical outcomes. This etiology‐based stratification might contribute to the diagnosis and management of type 2 diabetes.

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.

The differential role of uric acid - The purpose or cause of cardiovascular diseases?

For 40 years many studies have been conducted to verify the connection between serum uric acid concentration and cardiovascular diseases, such as myocardial infarction. Unfortunately, it remains unclear which form of uric acid - prooxidant or antioxidant - could be a predictive marker of cardiovascular disease, especially in patients after myocardial infarction. It is well-known that uric acid is an organic compound and the water-soluble final product of purine catabolism, which is catalysed by xanthine oxidoreductase and excreted by kidneys. An increased concentration of UA in human plasma leads to diseases like tumours, renal disorders, atherosclerosis, hypertension, diabetes, metabolic syndrome, polycythaemia vera, haemolytic anaemias, ischemia, oxidative stress, and rare genetic disorders connected with UA degradation. Epidemiological studies have shown that UA might be a marker of oxidative stress, progression of inflammation, or renal disease. A fortiori, it is possible that could also be a predictor for short/long-term survival of patients with CVD. Evidence provided by multiple studies is controversial and mutually exclusive. Among 71 studies the most of them found an independent association between SUA and CVD risk. Some of those studies confirm that CVD risk is higher in women who had elevated SUA levels. On the other hand, many studies reached the opposite conclusion and did not find any relationship between SUA and CVD mortality and morbidity.

Serum uric acid as a risk factor of all-cause mortality and cardiovascular events among type 2 diabetes population: Meta-analysis of correlational evidence

AIMS

To explore the association between serum uric acid (SUA) level and the risk of cardiovascular complications and all-cause mortality rates among individuals with type 2 diabetes.

METHODS

Web of Science and PubMed database were searched for studies reported associations between SUA level and cardiovascular complications and all-cause mortality among individuals with type 2 diabetes. Hazard ratios (HRs) were independently extracted by two investigators and synthesized through meta-analysis across selected studies.

RESULTS

6 (n = 11,750 patients), 4 (n = 3044 patients) and 2 studies (n = 7792 patients) were identified reporting associations between SUA level and all-cause mortality, coronary heart disease (CHD) and stroke respectively. HR for all-cause mortality, CHD, and stroke per 59 μmol/l increase was 1.06 (95% CI: 1.03, 1.09), 1.09 (95% CI: 0.94, 1.26) and 1.19 (95% CI: 1.08, 1.31), respectively.

CONCLUSIONS

Overall, the SUA level was associated with a higher risk of all-cause mortality and stroke. We found no significant association between SUA level and CHD among type 2 diabetes population.

High calcium intake from fat-free milk, body composition and glycaemic control in adults with type 2 diabetes: a randomised crossover clinical trial

We evaluated the effects of high-Ca fat-free milk v. low-Ca control diet on adiposity and on glycaemic control. Fourteen subjects with type 2 diabetes (aged 49·5 (sd 8·6) years, BMI 29·4 (sd 4·5) kg/m2, low habitual Ca consumption (<600 mg/d)) were included in this randomised, crossover clinical trial. Subjects participated in two 12-week experimental sessions (high-Ca fat-free milk (HC) or low-Ca control (LC)) separated by 8-week washout. Subjects daily consumed in the laboratory a breakfast shake containing 700 mg (HC) or 6·4 mg (LC) of Ca. Energy-restricted diets containing 800 mg of dietary Ca/d were prescribed. Dietary records data indicated the consumption of 1200 mg of Ca/d during HC and of 525 mg of Ca/d during LC. There was a greater reduction in body weight, body fat mass, waist circumference and waist:hip ratio after HC. Serum 25-hydoxyvitamin D and homeostatic model assessment-2 β-cell function (HOMA2-%B) increased, and serum uric acid, parathormone (PTH) and glycated Hb (HbA1c) concentrations reduced after HC. In addition, changes from baseline in terms of serum uric acid, glucose, HbA1c and PTH concentrations were lower, and those of HOMA2-%B, serum Ca and 25-hydoxyvitamin D were higher after the HC than after LC. The consumption of approximately three servings of fat-free milk and 1200 mg of dietary Ca/d enhanced weight loss, improved body composition and promoted glycaemic control in subjects with type 2 diabetes and low habitual Ca consumption (<600 mg/d).

Uric acid: from a biological advantage to a potential danger. A focus on cardiovascular effects

Non-communicable diseases represent nowadays the most common cause of death worldwide, having largely overcome infectious diseases. Among them, cardiovascular diseases constitute the majority. Given these premise, great efforts have been made by scientific societies to emphasize the fundamental role of cardiovascular prevention and risk factors control. In addition to classical cardiovascular risk factors such as smoking, arterial hypertension, hypercholesterolemia and male gender, new risk factors are emerging from international literature. Among them, uric acid is the protagonist. Several evidences show a direct role of hyperuricemia in the determinism of metabolic and vascular disorders. From the other hand, some researchers have demonstrated that uric acid is only a marker of cardiovascular damage and not a risk factor for its development. Aim of this review is to evaluate the scientific evidences on the role of uric acid in cardiovascular diseases in order to shed light on this confusing topic.

Platelet and Red Blood Cell Counts, as well as the Concentrations of Uric Acid, but Not Homocysteinaemia or Oxidative Stress, Contribute Mostly to Platelet Reactivity in Older Adults

Purpose

The goal of this study was to estimate the hierarchical contribution of the most commonly recognized cardiovascular risk factors associated with atherogenesis to activation and reactivity of blood platelets in a group of men and women at ages 60-65.

Methods

Socioeconomic and anthropometric data were taken from questionnaires. Blood morphology and biochemistry were measured with standard diagnostic methods. Plasma serum homocysteine was measured by immunochemical method. Plasma concentrations of VCAM, ICAM, total antioxidant status, and total oxidant status were estimated with commercial ELISA kits. Markers of oxidative stress of plasma and platelet proteins (concentrations of protein free thiol and amino groups) and lipids (concentrations of lipid peroxides) and generation of superoxide anion by platelets were measured with colorimetric methods. Platelet reactivity was estimated by impedance aggregometry with arachidonate, collagen, and ADP as agonists. Expression of selectin-P and GPIIb/IIIa on blood platelets was tested by flow cytometry.

Results

Platelet aggregation associated significantly negatively with HGB and age and significantly positively with PLT, MPV, PCT, PDW, and P-LCR. When platelet reactivity (“cumulative platelet reactivity_aggregation”) was analyzed in a cumulated manner, the negative association with serum concentration of uric acid (R_s = −0.169, p = 0.003) was confirmed. Multivariate analysis revealed that amongst blood morphological parameters, platelet count, plateletcrit, and number of large platelets and uric acid are the most predictive variables for platelet reactivity.

Conclusions

The most significant contributors to platelet reactivity in older subjects are platelet morphology, plasma uricaemia, and erythrocyte morphology.

Baseline Serum Uric Acid Levels Are Associated with All-Cause Mortality in Acute Coronary Syndrome Patients after Percutaneous Coronary Intervention

Background

Whether serum uric acid (UA) is associated with all-cause mortality in patients with acute coronary syndrome (ACS) following percutaneous coronary intervention (PCI) remains unclear.

Methods

We performed a retrospective cohort study of 2296 patients with ACS. Curve-fitting and Cox proportional-hazard regression models with a hazard ratio (HR) and 95% confidence interval (CI) were used.

Results

During a mean follow-up of 246.31 ± 49.16 days, 168 (7.32%) patients died from all causes. Patients were divided into two groups [the high-UA group (n = 566) and the low-UA group (n = 1730)] based on the serum UA threshold value (5.6 mg/dl) identified through curve fitting. Fifty-three (9.36%) patients died in the high-UA group, and 115 (6.65%) patients died in the low-UA group. The difference between groups was statistically significant (P = 0.031). Univariate analysis showed that the risk of all-cause mortality in the high-UA group was significantly greater than that in the low-UA group (HR = 1.45, 95% CI: 1.03 to 2.04). This difference persisted after adjustment for baseline characteristics, medical history, and medication history (HR = 1.42, 95% CI: 1.05 to 1.87).

Conclusions

Our study demonstrated that elevated serum UA (>5.6 mg/dl) is associated with all-cause mortality in ASC patients after PCI.

Relation of serum uric acid to asymptomatic proximal extracranial artery stenosis in a middle-aged Chinese population: a community-based cross-sectional study

OBJECTIVE

Serum uric acid (SUA) has been associated with cardiovascular diseases, including atherosclerosis and carotid artery stenosis. However, data on the relationship between SUA level and proximal extracranial artery stenosis (PEAS) are limited. Therefore, this study investigates the association between SUA levels and the risk of PEAS in asymptomatic Chinese population.

SETTING

This community-based cross-sectional study was conducted in Jidong Community Hospital, Tangshan, Hebei, China between July 2013 and August 2014.

PARTICIPANTS

The study examined 3325 asymptomatic participants (40-60 years) to evaluate the risk of PEAS.

RESULTS

For the participants stratified into quartiles based on gender-specific SUA levels, the prevalence of PEAS increased from Q1 to Q4 from 12.3% to 29.8% in the vertebral artery (VA), and from 2.8% to 5.8% in the common carotid artery. The proportion of PEAS relative to the detected number of arterial stenosis was lower in Q1 than in Q2-Q4. The multivariable ORs and 95% CI of PEAS in the second through fourth compared with the lowest quartiles for arterial stenosis were 1.278 (0.980 to 1.665), 1.117 (0.851 to 1.468) and 1.375 (1.033 to 1.830) (p_trend=0.0399); and for VA stenosis, 1.285 (0.966 to 1.709), 1.085 (0.808 to 1.457) and 1.439 (1.061 to 1.952) (p_trend=0.0235).

CONCLUSION

Elevated SUA concentration is significantly associated with PEAS in an asymptomatic middle-aged Chinese population, and vertebral arteries appeared to be the most vulnerable vessels.

The association between elevated serum uric acid levels and islet β-cell function indexes in newly diagnosed type 2 diabetes mellitus: a cross-sectional study

Background

Serum uric acid (UA) has been reported as a risk factor for type 2 diabetes mellitus (T2DM). However, whether serum UA is associated with insulin resistance and insulin secretion, and the effect of gender on it in the case of the existed association, both remain undefined.

Methods

A cross-sectional study was designed and performed, which enrolled a total of 403 newly diagnosed T2DM patients (mean age, 50.21 ± 13.34 years (62.5% males)). Clinical characteristics and islet function indexes of all participants were analyzed based on gender-specific tertiles of serum UA levels. In addition, multiple linear regression analysis was conducted to investigate covariates associated with islet function indexes.

Results

The mean levels of serum UA were 331.05 μmol/L (interquartile range (IQR): 60.6, 400.9 μmol/L) and 267.9 μmol/L (IQR: 204.7, 331.9 μmol/L) in men and women, respectively. The values of insulin secretion indexes involving AUCins30/glu30, AUCins120/glu120 and total insulin disposition index (DI120) in females were significantly higher than those in males. Apart from the homeostasis model assessment insulin resistance of men, serum UA was positively associated with insulin secretion and insulin resistance indexes both in men and women. Multivariable linear regression analysis showed serum UA exerted an independent impact on insulin secretion in females, but not on insulin resistance. In males, islet function was simultaneously affected by serum UA age, body mass index (BMI), and serum lipids.

Conclusion

Serum UA harbored a positive correlation with insulin secretion and insulin resistance indexes in newly diagnosed T2DM patients, which was influenced by gender, BMI, serum lipids. Hence, serum UA may be considered as a predictor for islet function in clinical practice.

The role of hyperuricemia on vascular endothelium dysfunction

Hyperuricemia appears to be associated with an increased risk for cardiovascular disease and associated mortality. Population epidemiological data support a causal link between hyperuricemia and cardiovascular disease. Endothelium injury could be one of the potential mechanisms in hyperuricemia-induced cardiovascular disease. However, the specific role of uric acid (UA) in the impairment of vascular relaxation and its signal transduction pathway has not been examined. The authors investigated the role of UA on vascular relaxation, nitric oxide (NO) production and expression of proinflammatory cytokines. Brachial flow-mediated dilation and nitroglycerine-mediated dilation were measured by B-mode ultrasound with 10 megahertz linear-array transducer from 21 patients with hyperuricemia and 16 control subjects. Human umbilical vein endothelial cells (ECs) were incubated with UA (5-15 mg/dl) with or without nuclear factor (NF)-κB inhibitor II. Hyperuricemia inhibited brachial flow-mediated dilation. While UA significantly inhibited NO expression with time course- and dose- dependent manner in the cultured ECs, 10 mg/dl UA also increased expression of inflammation cytokine interleukin (IL)-6, IL-8 and tumor necrosis factor-α in vitro. These abnormalities were associated with UA-induced activation of transcription factor NF-κB. Furthermore, NF-κB inhibitor II prevented UA-induced reduction of NO and increased inflammation cytokines. These data suggested hyperuricemia-induced endothelium injury and vascular dysfunction by a reduction of NO and expression of inflammatory cytokines through the NF-κB pathway.

Serum Uric Acid and Impaired Glucose Tolerance: The Cardiometabolic Risk in Chinese (CRC) Study

Serum uric acid (SUA) elevation has been previously related to impaired fasting glucose and type 2 diabetes. The present study was comprehensive to examine the associations between SUA and impaired glucose tolerance (IGT) in Chinese adults. For this purpose, data were collected from a community-based health examination survey conducted in Central China; 2-h glucose (OGTT) and SUA were measured in 1956 men and women. In multivariate models, SUA levels were significantly associated with an increasing trend of 2-h glucose (OGTT) (P for trend < 0.0001). The odds ratios (OR; 95 % CI) of IGT across increasing quartiles of SUA were 1.0, 1.354 (0.948-2.087), 1.337 (0.959-2.251), and 2.192 (1.407-3.416), after adjusting for age, sex, body mass index, waist circumference, fasting insulin, blood pressure, serum lipids, serum creatinine, and estimated glomerular filtration rate. (P for trend = 0.001). In addition, we found an additive pattern between SUA and triglyceride (TG; P = 0.038) or between SUA and low-density lipoprotein cholesterol (LDL-C; P = 0.041) in relation to IGT. SUA was related to IGT in the Chinese adults, independent of other conventional metabolic risk factors. TG and LDL-C might modify the associations.

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.

Comparison of the effects of metoprolol or carvedilol on serum gamma-glutamyltransferase and uric acid levels among patients with acute coronary syndrome without ST segment elevation

Objective:

Serum gamma-glutamyltransferase (GGT) and uric acid levels measured in patients with acute coronary syndrome without ST segment elevation (NSTEMI) are important in diagnosis and in predicting the prognosis of the disease. There is a limited number of clinical studies investigating the effects of beta-blockers on GGT and uric acid levels in these patients. In our study, we aimed to investigate the effects of beta-blocker therapy on GGT and uric acid levels.

Methods:

We conducted a randomized, prospective clinical study. Hundred patients with NSTEMI were included in this study, and they were divided into two groups. Fifty patients were administered metoprolol succinate treatment (1 × 50 mg), whereas the remaining 50 patients were administered carvedilol treatment (2 × 12.5 mg). Thereafter, all of the patients underwent coronary angiography. Blood samples were taken at the time of admission, at the 1^st month, and 3^rd month to detect GGT and uric acid levels.

Results:

There was no statistically significant difference among the metoprolol or carvedilol groups in terms of the GGT levels measured at the baseline, 1^st month, and 3^rd month (p=0.904 and p=0.573, respectively). In addition, there was no statistically significant difference among the metoprolol or carvedilol groups in terms of uric acid levels measured at the baseline, 1^st month, and 3^rd month (p=0.601 and p=0.601, respectively).

Conclusion:

We found that GGT and uric acid levels did not show any change compared to the baseline values, with metoprolol and carvedilol treatment initiated in the early period in patients with NSTEMI.

Clopidogrel resistance response in patients with coronary artery disease and metabolic syndrome: the role of hyperglycemia and obesity

BACKGROUND

Despite the proven benefits of clopidogrel combined aspirin therapy for coronary artery disease (CAD), CAD patients with metabolic syndrome (MS) still tend to have coronary thrombotic events. We aimed to investigate the influence of metabolic risk factors on the efficacy of clopidogrel treatment in patients with CAD undergoing percutaneous coronary intervention (PCI).

METHODS

Cohorts of 168 MS and 168 non-MS subjects with CAD identified by coronary angiography (CAG) were enrolled in our study. MS was defined by modified Adult Treatment Panel III criteria. All subjects had taken 100 mg aspirin and 75 mg clopidogrel daily for more than 1 month, and administered loading doses of 600 mg clopidogrel and 300 mg aspirin before PCI. Blood samples were taken 24 h after the loading doses of clopidogrel and aspirin. Platelet aggregation was measured using light transmittance aggregometry (LTA) and thrombelastography (TEG). Clopidogrel resistance was defined as more than 50% adenosine diphosphate (ADP) induced platelet aggregation as measured by TEG.

RESULTS

Platelet aggregation inhibition rate by ADP was significantly lower in patients with MS as measured both by TEG (55% ± 31% vs. 68% ± 32%; P < 0.001) and LTA (29% ± 23% vs. 42% ± 29%; P < 0.001). In the multivariate analysis, elderly [OR (95% CI): 1.483 (1.047-6.248); P = 0.002], obesity [OR (95% CI): 3.608 (1.241-10.488); P = 0.018], high fasting plasma glucose level [OR (95% CI): 2.717 (1.176-6.277); P = 0.019] and hyperuricemia [OR (95% CI): 2.583 (1.095-6.094); P = 0.030] were all statistically risk factors for clopidogrel resistance. CAD patients with diabetes and obesity were more likely to have clopidogrel resistance than the CAD patients without diabetes and obesity [75% (61/81) vs. 43% (67/156); P < 0.001].

CONCLUSIONS

CAD patients with MS appeared to have poorer antiplatelet response to clopidogrel compared to those without MS. Obesity, diabetes and hyperuricemia were all significantly associated with clopidogrel resistance.