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

Effect of high sensitivity C-reactive protein on uric acid-related cardiometabolic risk in patients with coronary artery disease-a large multicenter prospective study

Although serum uric acid (SUA) is a risk factor for cardiometabolic outcome, but it remains unclear which patients with coronary artery disease (CAD) benefit the most from SUA lowering therapy (ULT). The association of SUA level, systemic inflammation and cardiometabolic risk is still unclear. The current study is aimed to examine whether SUA-associated cardiometabolic risk is modulated by systemic inflammation in CAD patients. A total of 16,598 CAD patients with baseline high-sensitivity C-Reactive Protein (hsCRP) and SUA available were included. Baseline and follow-up data were collected. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including death, myocardial infarction and stroke. In patients with hsCRP ≥ 2 mg/L, increasing quintiles of SUA were significantly associated with increased rates of 2-year MACCE (adjusted p < 0.001 for trend, p = 0.037 for interaction). Each unit increase in SUA levels was associated with a 11.3% increased risk of MACCE (adjusted p < 0.001, p = 0.002 for interaction). However, in patients with hsCRP < 2 mg/L, increasing quintiles of SUA were not associated with increased MACCE (adjusted p = 0.120). Elevated SUA levels are related to MACCE when hsCRP levels are 2 mg/L or more but not less than 2 mg/L. This finding suggests a potential benefit of combined ULT and anti-inflammation therapy in patients with hyperuricemia and greater systemic inflammation.

Association between serum level of urate and subclinical atherosclerosis: results from the SCAPIS Pilot

BACKGROUND

Hyperuricemia is closely associated with cardiovascular disease (CVD). However, it has not been definitively established whether this association is independent of traditional cardiovascular risk factors (CVRFs) and whether it is gender-dependent. The aim of this study was to investigate in a population-based cohort (age range, 50-64 years) stratified by sex the association between the serum urate (SU) concentration and subclinical atherosclerosis, as reflected in the coronary artery calcification (CAC) score, common carotid intima-media thickness (CIMT), and carotid plaque score.

METHODS

The study involved participants in the Swedish CArdioPulmonary bioImage Study (SCAPIS) Pilot cohort (N = 1040; 48.8% males). This pilot cohort is part of the large population-based SCAPIS with 30,000 participants in the age range of 50-64 years, aimed at improving risk prediction for CVD. Subjects with a self-reported previous history of CVD (N = 68) or gout (N = 3) were excluded. The CAC score was assessed with the Agatston method using computed tomography. CIMT and carotid plaques were quantified by ultrasound. The associations between the SU quartiles and different levels of CAC, CIMT, and carotid plaques were assessed by multivariable logistic regression.

RESULTS

Age, BMI, education level, smoking, physical activity, hs-CRP, hypertension, and dyslipidemia showed no differences between males and females, while CAC (score > 0) and diabetes were both twice as common in men than in women (58% vs 26% and 8% vs 4%, respectively). Higher SU quartiles were in both sexes associated with BMI, hs-CRP, and the prevalence of hypertension, and in women, they were also associated with the prevalence of dyslipidemia. The three upper quartiles of SU (>308μmol/L) were linked to higher CAC scores in men, when adjusting for CVRFs, but not in women. CIMT and carotid plaques showed no correlation to SU in either sex.

CONCLUSIONS

Higher levels of SU are associated with the presence of CAC in men but not in women, whereas SU is not associated with CIMT or carotid plaques in either men or women. This implies that the biological effects of SU differ in men and women or that SU has varying effects on different vascular beds or during the different stages of the atherosclerotic process.

Association between uric acid and brachial-ankle pulse wave velocity: secondary analysis of data from a cross-sectional study

At present, the association between uric acid (UA) and brachial-ankle pulse wave velocity (baPWV) has not been well clarified. This study is the second analysis based on a cross-sectional study. 912 participants (average age is 51.5 ± 9.6 years) who underwent medical health examinations were included in this study, UA levels and baPWV were measured. Participants were divided into four groups according to UA levels (Quantile 1: 2.00-4.10 mg/dL; Quantile 2: 4.20-5.20 mg/dL; Quantile 3: 5.30-6.00 mg/dL and Quantile 4: 6.10-9.80 mg/dL), and the differences of baPWV between the four groups were compared. Univariate analysis showed a positive correlation between UA and baPWV [(Quantile 2 vs Quantile 1: 8.85 (-36.05, 53.75); Quantile 3 vs Quantile 1: 60.32 (13.22, 107.42) and Quantile 4 vs Quantile 1: 80.34 (36.19, 124.49)]. After adjusting for confounding factors, the positive correlation between UA and baPWV still exists [(Quantile 2 vs Quantile 1: -9.92 (-60.16, 40.32); Quantile 3 vs Quantile 1: 82.34 (4.00, 160.68) and Quantile 4 vs Quantile 1: 143.13 (0.75, 285.51)]. Furthermore, curve fitting showed that UA and baPWV had a non-linear positive correlation. In conclusion, elevated UA were associated with baPWV, suggesting that UA could be used as a predictor of atherosclerosis.

Association between serum uric acid levels and coronary artery disease in different age and gender: a cross-sectional study

BACKGROUND

The association between uric acid (UA) and coronary artery disease (CAD) was controversial. It was still unclear how the UA level changes with age and gender.

AIMS

To confirm the relationship between the change of UA with age and gender and CAD, especially in elderly people.

METHODS

8285 individuals were investigated. The changes of UA and hyperuricemia in female and male with age were analyzed. The associations of UA, and hyperuricemia with CAD in different age and sex were assessed.

RESULTS

Individuals were stratified into four groups according to their age: ≤ 39 years; 40-59 years; 60-79 years, and ≥ 80 years. The level of UA and the proportion of hyperuricemia increased significantly with age in female (P < 0.001), but showed a downward trend in male (P < 0.001). After adjusting for confounding factors, hyperuricemia remained an independent risk factor for the incident of CAD in all women (P = 0.029). In ≥ 80 year groups of female, UA and hyperuricemia became independent risk factors for the incident of CAD in the univariate and multivariate logistic regression analyses (all P ≤ 0.001).

DISCUSSION

The level of UA showed significantly different changes with age in different gender. The relationship between UA and CAD showed differences in different age and sex.

CONCLUSIONS

There were significant correlations between UA, hyperuricemia, and CAD only in female, particularly in the ≥ 80 year elderly women, but not in men.

Silent Monosodium Urate Crystal Deposits Are Associated With Severe Coronary Calcification in Asymptomatic Hyperuricemia: An Exploratory Study

OBJECTIVE

To evaluate the association between monosodium urate (MSU) crystal deposits in patients with asymptomatic hyperuricemia and the severity and extension of coronary artery disease (CAD).

METHODS

In this cross-sectional study, consecutive inpatients with a non-ST elevation acute coronary event and asymptomatic hyperuricemia (serum uric acid concentration of ≥7.0 mg/dl) or normouricemia (serum uric acid concentration of <7.0 mg/dl) were enrolled. In patients with asymptomatic hyperuricemia, the presence of MSU crystals was determined by ultrasound evaluation of both knees and first metatarsophalangeal joints and by compensated polarized light microscopy. CAD was assessed by coronary angiography, and the following variables were considered: 1) the presence of moderate-to-severe coronary artery calcification, 2) the number of significant coronary stenoses, and 3) the presence of multivessel disease. The association between variables indicating the severity of CAD and the presence of MSU crystals was analyzed by multivariate regression.

RESULTS

One hundred forty patients were enrolled. After ultrasonography and microscopic analyses were performed, the patients were classified as having normouricemia (n = 66), asymptomatic hyperuricemia alone (n = 61), and asymptomatic hyperuricemia with MSU crystals (n = 13). The prevalence of moderate-to-severe coronary calcification was significantly higher in the patients with asymptomatic hyperuricemia with MSU crystals compared with patients with asymptomatic hyperuricemia alone and patients with normouricemia (P = 0.003). An independent association was observed between the presence of moderate-to-severe calcification and asymptomatic hyperuricemia with crystals (odds ratio 16.8, P = 0.002). No significant association was observed for the other variables.

CONCLUSION

Silent deposition of MSU crystals in patients with asymptomatic hyperuricemia was associated with more severe coronary calcification, which suggests more severe CAD in relation to crystal deposition.

Serum uric acid concentration is associated with hypertensive retinopathy in hypertensive chinese adults

BACKGROUND

This cross sectional investigation included 12,966 subjects with hypertension, a cohort of the China Stroke Primary Prevention Trial (CSPPT), a randomized, multicenter clinical trial. This study aimed to explore the correlation between serum uric acid (SUA) concentration and hypertensive retinopathy in hypertensive adults.

METHODS

Diagnosis of hypertensive retinopathy was determined by non-mydriatic fundus photography and classified with Keith-Wagener-Barker (KWB) system. The correlation of SUA levels with hypertensive retinopathy prevalence and severity was assessed by statistical analysis.

RESULTS

9848 (75.95%) subjects were diagnosed with hypertensive retinopathy with the following retinopathy grade distribution: grade 1: 58.80%, grade 2: 14.81%, and grade 3-4: 2.34%. SUA levels were significantly associated with hypertensive retinopathy prevalence. Patients with hypertensive retinopathy had higher SUA levels than those without hypertensive retinopathy. Patients in the highest uric acid quartile had an odds ratio for hypertensive retinopathy of 1.21 compared to patients in the lowest uric acid quartile (OR = 1.21, 95% CI: 1.05-1.40, P = 0.008). When compared to the non-hyperuricemia group, those in the hyperuricemia group had an odds ratio for hypertensive retinopathy of 1.18(OR = 1.18, 95% CI: 1.05-1.33, P = 0.004). Every 1 mg/dl increase in uric acid concentration was significantly associated with a 6% higher odds of hypertensive retinopathy (OR = 1.06, 95% CI: 1.02-1.10, P = 0.002).

CONCLUSIONS

The prevalence of hypertensive retinopathy was high (75.95%) among hypertensives in our patients cohort. In addition, SUA concentration was significantly associated with hypertensive retinopathy.

Impact of Serum Uric Acid Levels on Coronary Plaque Stability Evaluated Using Integrated Backscatter Intravascular Ultrasound in Patients with Coronary Artery Disease

AIM

Because the prevalence of hyperuricemia is lower in females than in males, the association between hyperuricemia and cardiovascular disease has been frequently reported in females. Increased serum uric acid levels are associated with the presence of cardiovascular risk factors such as hypertension, renal dysfunction, insulin resistance, and metabolic syndrome. However, it is controversial whether hyperuricemia is an independent risk factor for coronary artery disease in both the genders. The purpose of this study was to investigate the relationship between serum uric acid levels and coronary plaque components assessed using integrated backscatter intravascular ultrasound (IB-IVUS) in males and females.

METHODS

In total, 385 patients (298 males and 87 females) who underwent percutaneous coronary intervention using IB-IVUS were divided into three groups in each gender according to their serum uric acid levels. We characterized tissue from coronary plaques in culprit lesions.

RESULTS

Serum uric acid levels significantly correlated with percent lipid volume (r=0.37) and inversely correlated with percent fibrous volume (r=－0.35). Multivariate analysis showed that the uric acid level was independently associated with lipid-rich plaques (odds ratio 2.43, 95%, confidence interval 1.75-3.47). The prevalence of lipid-rich plaques increased with increasing uric acid levels in both genders.

CONCLUSION

Increased serum uric acid levels were associated with larger lipid content plaques in both genders.

Uric acid enhances PKC-dependent eNOS phosphorylation and mediates cellular ER stress: A mechanism for uric acid-induced endothelial dysfunction

The mechanism by which hyperuricemia induced-endothelial dysfunction contributes to cardiovascular diseases (CVDs) is not yet fully understood. In the present study, we used uric acid (UA) to trigger endothelial dysfunction in cultured endothelial cells, and investigated the effects of induced reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress induction, and the protein kinase C (PKC)-dependent endothelial nitric oxide synthase (eNOS) signaling pathway. Human umbilical vein endothelial cells (HUVECs) were incubated with 6, 9 or 12 mg/dl UA, ROS scavenger polyethylene glycol-superoxide dismutase (PEG‑SOD), ER stress inhibitor 4-phenylbutyric acid (4-PBA), and PKC inhibitor polymyxin B for 6-48 h. Nitric oxide (NO) production, eNOS activity, intracellular ROS, ER stress levels, and the interaction between eNOS and calmodulin (CaM) and cytosolic calcium levels were assessed using fluorescence microscopy and western blot analysis. Apoptosis was assessed by annexin V staining. UA increased HUVEC apoptosis and reduced eNOS activity and NO production in a dose- and time-dependent manner. Intracellular ROS was elevated after 3 h, while ER stress level increased after 6 h. UA did not alter intracellular Ca2+, CaM, or eNOS concentration, or eNOS Ser1177 phosphorylation. However, PKC-dependent eNOS phosphorylation at Thr495 was greatly enhanced, and consequently interaction between eNOS and CaM was reduced. Cellular ROS depletion, ER stress inhibition and PKC activity reduction inhibited the effect of UA on eNOS activity, NO release and apoptosis in HUVECs. Thus, we concluded that UA induced HUVEC apoptosis and endothelial dysfunction by triggering oxidative and ER stress through PKC/eNOS-mediated eNOS activity and NO production.