Independent association of high serum uric acid concentration with angiographically defined coronary artery disease

The Relationship between Serum Vitamin C and Uric Acid Levels, Antioxidant Status and Coronary Artery Disease: a Case-Control Study

Coronary artery disease (CAD) is among the main causes of death in adults. Increase of oxidative stress and defects in antioxidant defense play a major role in endothelium performance and are affecting factors in the progress of atherosclerosis. The aim of this study was to measure serum levels of uric acid (UA) and vitamin C as well as the antioxidant status in patients with CAD, and compared them with those in healthy individuals. The present case-control study was performed on 44 cases and 44 controls. Demographic data and anthropometric indices were measured. The Food Frequency Questionnaire (FFQ) and International Physical Activity Questionnaire (IPAQ) were completed. After 12 hours of fasting,10 mL blood was sampled from the participants. Serum levels of UA, vitamin C, Total Antioxidant Capacity (TAC) and Malondialdehyde (MDA) were also measured. The data were finally analyzed by SPSS v22. A significant difference was observed between the groups in terms of UA and vitamin C. However, mean levels of MDA and TAC were not significantly different between groups. The differences between groups in terms of vitamin A, vitamin E, beta-carotene, zinc and selenium intakes were not significant either. A significant difference was detected between the groups in terms of vitamin C intake. Our results suggest that increase in UA and decrease in vitamin C in serum levels can be considered as risk factors for CAD patients. Due to a lack of any significant correlation between TAC and CAD risk in this study, further study with bigger sample size is needed.

Association Between the Serum Uric Acid Level and the Severity of Coronary Artery Disease in a Retrospective Study of China Nondialysis CKD Patients

Introduction: Hyperuricemia has been associated with increased cardiovascular events in the general population. However, the role of serum uric acid (SUA) level on the severity of coronary artery stenosis (CAS) in nondialysis chronic kidney disease (CKD) patients is obscure. Methods: We implement a retrospective cohort study of 734 patients diagnosed with stage 3-5 CKD. All selected patients underwent coronary artery angiography. The associations of SUA with the present, and severity of coronary artery disease (CAD) were analyzed. Results: Of these 734 patients, 511 patients had angiographically proven CAD. Compared with non-CAD group, the SUA level in CAD group was much higher (388.00 vs. 363.00 μmol/l, P < 0.01). After adjusting for multiple confounding factors, a multivariate logistic regression analysis demonstrated that SUA was relevant to the presence of CAD when SUA as a continuous variable. However, this relationship was not observed with SUA as a categorical variable. In a subgroup analysis for the CAD group, we found that the rates of severe CAS in the third tertile of SUA (58.6%) was higher than that in the first tertile (41.6%) (P < 0.01). Compared with the first tertile of SUA, the third tertile of SUA was an independent risk factor for severe arterial stenosis (odds ratio, OR, 1.976 [1.203-3.248]), a pattern that was recapitulated by multivariate logistic regression analysis with SUA as a continuous variable (1.002 [1.000-1.004]). Conclusions: The SUA level may serve as a predictor of the severity of CAS among nondialysis CKD patients with CAD.

Sattar MAA. The possible antianginal effect of allopurinol in vasopressin-induced ischemic model in rats

The anti-anginal effects of allopurinol were assessed in experimental model rats of angina and their effects were evaluated with amlodipine. In the vasopressin-induced angina model, oral administration of allopurinol in dose of 10 mg/kg revealed remarkably analogous effects in comparison with amlodipine such as dose-dependent suppression of vasopressin-triggered time, duration and severity of ST depression. In addition, allopurinol produced dose dependent suppression of plasma Malondialdehyde (MDA) level, systolic blood pressure, cardiac contractility and cardiac oxygen consumption; while in contrast, amlodipine minimally suppressed the elevation of plasma MDA level. Endothelial NO synthase (eNOS) expression, serum nitrate were strikingly increased, however lipid profile was significantly reduced. Seemingly, allopurinol was found to be more potent than amlodipine – a calcium channel antagonist. To conclude, it was explicitly observed and verified that on the ischemic electrocardiography (ECG) changes in angina pectoris model in rats, allopurinol exerts a significant protective effects, reminiscent of enhancement of vascular oxidative stress, function of endothelial cells, improved coronary blood flow in addition to the potential enhancement in myocardial stress. Moreover, our findings were in conformity with several human studies.

Effect of serum uric acid on the positive predictive value of dobutamine stress echocardiography

There is controversial data regarding the relationship between uric acid (UA) and coronary artery disease and cardiovascular events. Despite the deleterious effects of hyperuricemia on endothelial function, the effect of UA on myocardial ischemia has not been previously studied. We aimed to investigate the relationship between UA and myocardial ischemia that was identified using dobutamine stress echocardiography (DSE). In this retrospective study, the laboratory and DSE reports of 548 patients were reviewed. The patients were divided into two groups based on the presence of ischemia and further subdivided into three groups according to the extent of ischemia (none, ischemia in 1-3 segments, ischemia in >3 segments). Serum UA levels were compared. Determinants of ischemia were assessed using a regression model. UA was increased in patients with ischemia and was correlated with the number of ischemic segments (p < 0.001). A cutoff value of UA > 5 mg/dl had 63.9 % sensitivity, 62.0 % specificity, 42.5 % positive predictive value (PPV), and 79.6 % negative predictive value for ischemia. When the positive DSE exams were further sorted according to the UA cutoff, the PPV of DSE increased from 80.2 to 94.0 %. Uric acid (odds ratio 1.51; 95 % CI 1.14-1.99), diabetes mellitus, HDL and glomerular filtration rate were found to be independent determinants of myocardial ischemia in DSE. Increased UA is associated with both the presence and extent of DSE-identified myocardial ischemia. A UA cutoff may be a good method to improve the PPV of DSE.

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.

High Levels of Serum Uric Acid Impair Development of Coronary Collaterals in Patients With Acute Coronary Syndrome

We evaluated the association of serum uric acid (SUA) level and development of coronary collateral vessels (CCVs) in patients with acute coronary syndrome (ACS). Patients (n = 224) with ACS were included in the study. Coronary collateral vessels were graded according to the Rentrop scoring system. Rentrop grade 0 was accepted as absence of CCV (group 1; n = 117) and Rentrop grade ≥1 was accepted as presence of CCV (group 2; n = 107). Rentrop 0-1 (poor CCV) were determined in 167 patients and Rentrop 2-3 (good CCV) were determined in 57 patients. Both presence of CCV ( P < .001) and development of good CCV ( P = .003) were significantly associated with low levels of SUA. We suggest that high levels of SUA affect the CCV development negatively in nondiabetic and nonhypertensive patients with ACS.

Uric acid and pentraxin-3 levels are independently associated with coronary artery disease risk in patients with stage 2 and 3 kidney disease

BACKGROUND AND OBJECTIVES

Cardiovascular disease is prevalent in chronic kidney disease (CKD). Uric acid is increased in subjects with CKD and has been linked with cardiovascular mortality in this population. However, no study has evaluated the relationship of uric acid with angiographically proven coronary artery disease (CAD) in this population. We therefore investigated the link between serum uric acid (SUA) levels and (i) extent of CAD assessed by the Gensini score and (ii) inflammatory parameters, including C-reactive protein (CRP) and pentraxin-3, in patients with mild-to-moderate CKD.

MATERIAL AND METHODS

In an unselected population of 130 patients with estimated glomerular filtration rate (eGFR) between 90 and 30 ml/min/1.73 m(2), we measured SUA, serum pentraxin-3, CRP, urinary protein-to-creatinine ratio, lipid parameters and the severity of CAD as assessed by coronary angiography and quantified by the Gensini lesion severity score.

RESULTS

The mean serum values for SUA, pentraxin-3 and CRP in the entire study population were 5.5 ± 1.5 mg/dl, 6.4 ± 3.4 ng/ml and 3.5 ± 2.6 mg/dl, respectively. The Gensini scores significantly correlated in univariate analysis with gender (R = -0.379, p = 0.02), uric acid (R = 0.42, p = 0.001), pentraxin-3 (R = 0.54, p = 0.001), CRP (R = 0.29, p = 0.006) levels, eGFR (R = -0.33, p = 0.02), proteinuria (R = 0.21, p = 0.01), and presence of hypertension (R = 0.37, p = 0.001), but not with smoking status, diabetes mellitus, and lipid parameters. After adjustments for traditional cardiovascular risk factors, only uric acid (R = 0.21, p = 0.02) and pentraxin-3 (R = 0.28, p = 0.01) remained significant predictors of the Gensini score.

CONCLUSIONS

SUA and pentraxin-3 levels are independent determinants of severity of CAD in patients with mild-to-moderate CKD. We recommend a clinical trial to determine whether lowering uric acid could prevent progression of CAD in patients with CKD.

Association between laboratory markers and presence of coronary artery disease

The aim of this paper is to elucidate the relation between laboratory markers and coronary artery disease (CAD).

METHODS

The study involved 1254 consecutive patients with suspected or known CAD referred for coronary angiography. The blood samples including blood cell count, C-reactive protein, fibrinogen, uric acid, creatinine, and lipid spectrum were obtained after overnight fasting. One hundred and thirty-three patients were excluded due to incomplete records or inacceptable laboratory values. Differences among groups were tested with one-way ANOVA and Bonferroni post-hoc test for continuous variables and with chi-square test for categorical variables. Univariate and multivariate logistic regression was adopted for the analysis of risk factors and development of models for classification of patients into clinical categories.

RESULTS

The linear logistic regression showed association of patient's biochemical markers with the presence of disease. Both acute and chronic CAD were associated with leukocyte count (Odds ratios 1.45 and 1.26), CRP (1.13; 1.05), fibrinogen (4.23; 1.95), uric acid (1.27; 1.38), creatinine (1.04; 1.04), HDL cholesterol (0.07; 0.12), triglycerides (1.4; 1.52) and glucose (1.56; 1.39). Presence of insignificant atherosclerosis was influenced only by fibrinogen (OR 1.73), creatinine (1.02), HDL cholesterol (0.5) and glucose level (1.23). There was no difference between one- and multivessel disease in laboratory values.

CONCLUSION

Leukocyte count, CRP level, triglycerides and uric acid are associated with the presence of both acute and chronic ischaemic heart disease, but not with number of stenosed vessels. In addition, glycemia, HDL cholesterol and namely fibrinogen and creatinine have relation to occurence of insignificant atherosclerosis.

High serum uric acid and low-grade inflammation are associated with smaller LDL and HDL particles

Elevated serum uric acid (UA) is associated with higher risk for cardiovascular disease (CVD). Smaller, denser low density lipoprotein (LDL) and high-density lipoprotein (HDL) particles are the potential risk factors for CVD, while the role and diagnostic value of inflammatory markers are firmly established. This current cross-sectional study investigates interrelationships between UA, high sensitivity C-reactive protein (hsCRP) and fibrinogen concentrations with LDL and HDL sizes in healthy middle-aged subjects. The outcomes-of-interest were smaller, denser LDL and HDL particles (LDL size <or=25.5nm and HDL size <or=8.8nm). Serum UA, hsCRP and plasma fibrinogen concentrations were measured by standard laboratory methods in a sample of 194 healthy volunteers (112 men and 82 women). LDL and HDL particle sizes were determined by gradient gel electrophoresis. The subjects in the highest UA tertile had significantly smaller LDL and HDL particle sizes (P<0.05 and P<0.01, respectively) and higher concentrations of fibrinogen and hsCRP (P<0.05 and P<0.01, respectively). Elevated UA (>or=318micromol/L) was a significant predictor of smaller, denser LDL and HDL particles (OR=3.09; P<0.01; n=19 and OR=4.40; P<0.001; n=23, respectively). The observed relationship with smaller HDL size persisted after adjustment for conventional cardiovascular risk factors. UA strongly correlated with both markers of inflammation. In addition, the higher hsCRP level correlated with smaller LDL size (P<0.05), while fibrinogen concentration was inversely related to HDL size (P<0.05). Multiple regression analysis revealed that HDL size and inflammatory markers remained independent determinants of UA concentration. In conclusion, higher serum UA and low-grade inflammation are closely linked to alterations in lipoprotein metabolism which may represent an early sign of atherosclerosis in asymptomatic subjects.

Small arterial elasticity predicts the extent of coronary artery disease: Relationship with serum uric acid

BACKGROUND

Arterial elasticity has been previously linked to atherosclerotic vascular disease states. Serum uric acid level has been recently associated with increased arterial stiffness, but to what extent serum uric acid reflects angiographic coronary artery status and vessel compliance remains to be established. In this study we aimed to evaluate the association of arterial elasticity indexes, serum uric acid and the presence and extent of angiographic coronary artery disease (CAD) in patients with chronic stable angina.

METHODS

One hundred and eight consecutive patients attending for elective coronary angiography were investigated. The severity of CAD was expressed using the Gensini score. Quantitative analysis of the arterial elasticity was performed by applanation tonometry. Serum uric acid was measured in all participants. Stepwise multiple linear regression analysis was used to identify the independent correlates of the Gensini score.

RESULTS

After adjustment for age, gender, common cardiac risk factors and cardiovascular drugs, small artery elasticity index (SAEI) (p<0.001) and serum uric acid (p<0.001) were independently correlated with the severity of CAD. Stepwise multiple linear regression analysis was also used to identify independent correlates of the SAEI. Serum uric acid emerged as the only independent correlate of SAEI (p<0.001).

CONCLUSIONS

SAEI independently reflects the extent of CAD in patients with chronic stable angina. This relationship is chiefly mediated by serum uric acid. Our data add to the growing evidence that serum uric acid may be a marker of arterial stiffness and atherosclerotic burden.