Hyperuricemia and coronary heart disease: The mediating role of blood pressure and thrombospondin 3

BACKGROUND & AIMS

Although hyperuricemia is a known risk factor for coronary heart disease (CHD), little is known about the role of blood pressure in mediating this association. The purpose of this study is to investigate the role of blood pressure-related indicators and Thrombospondin 3 (THBS3) in the association between hyperuricemia and CHD.

METHODS AND RESULTS

Our observational epidemiology study included 593 CHD cases and 760 controls from a residential stable sample. We also chose 43 new CHD patients and 43 controls to test the expression levels of THBS3 using ELISA kits. We used logistic regression models and mediating effect analysis to investigate the relationships between hyperuricemia and CHD, as well as the mediating role of blood pressure-related indicators and THBS3. In the general population (OR: 2.001 [95% CI: 1.528-2.622]), male population (OR: 1.591 [95% CI: 1.119-2.262]), and female population (OR: 2.813 [95% CI: 1.836-4.310]), hyperuricemia is an independent risk factor for CHD. In general, average systolic blood pressure (SBP) and average pulse pressure difference (PPD) mediated 3.35% and 4.59%, respectively, of the association between hyperuricemia and CHD, and 6.60% and 6.60% in women. However, in the male population, we have not yet found that blood pressure-related indicators had a significant mediating effect. Meanwhile, we found that THBS3 mediated 19.23% of the association between hyperuricemia and CHD.

CONCLUSIONS

Average SBP, PPD, and THBS3 all play a role in the association of hyperuricemia and CHD. In the female population, similar mediating results in blood pressure-related indicators were observed.

Circulating Biomarkers in Coronary Microvascular Dysfunction

Coronary microvascular dysfunction is an underdiagnosed pathologic process that is associated with adverse clinical outcomes. Biomarkers, molecules measurable in the blood, could inform the clinician by aiding in the diagnosis and management of coronary microvascular dysfunction. We present an updated review of circulating biomarkers in coronary microvascular dysfunction representing key pathologic processes, including inflammation, endothelial dysfunction, oxidative stress, coagulation, and other mechanisms.

Raised total methylated arginine load in patients with gout

Aim: The aim of this study was to measure serum levels of methylarginine derivatives and related metabolites in patients with gout. Materials & methods: This study enrolled 100 patients with gout and 80 patients in the control group. Serum asymmetric dimethylarginine, symmetric dimethylarginine, L-N-monomethylarginine, arginine, homoarginine, citrulline and ornithine levels were measured with tandem mass spectrometry. Results: Serum ornithine, citrulline and total methylated arginine load levels were statistically significantly higher in patients with gout compared with the control group, while serum arginine and homoarginine levels and global arginine bioavailability ratio were statistically significantly lower. Conclusion: There may be an association between gout, methylarginine levels and hyperuricemia and increased risk of cardiovascular disease.

Association Between Uric Acid and Worsening Peripheral Microangiopathy in Systemic Sclerosis

Objective: The key element in the pathogenesis of systemic sclerosis (SSc) is microcirculatory changes in several vascular beds. Uric acid is associated with endothelial dysfunction and therefore, microvascular damage. The aim of this study was to examine the association between uric acid (UA) and peripheral microvascular involvement in patients with SSc. Methods: We included consecutive, consenting patients with SSc. Serum UA, urea and creatinine were measured, and glomerular filtration rate (GFR) was calculated with CKD-EPI. All participants underwent nailfold video-capillaroscopy (NVC) to evaluate the microcirculation. Results: A total of 64 patients (95.3% women) were included in the study. UA levels were significantly associated with the number of avascular areas (r = 0.290; p = 0.020), whereas no correlation was shown for the GFR (r = -0.065; p = 0.609). A significant trend of UA in the three capillaroscopic patterns was shown (3.90 ± 1.52 vs. 4.15 ± 0.98 vs. 5.38 ± 2.26; for early, active, and late patterns respectively, p = 0.028). Multivariate analysis showed that male gender (β = 3.049; 95% CI = 0.997-5.101) and UA (β = 0.352; 95% CI = 0.117-0.588) were independently associated with the number of avascular areas. Conclusion: These data suggest that UA levels are significantly associated with the capillaroscopic patterns, reflecting a progressive microvasculopathy.

Hyperuricemia prevalence in healthy subjects and its relationship with cardiovascular target organ damage

BACKGROUND AND AIM

Heterogeneous results have been obtained in the relationship between Uric Acid (UA) and Target Organ Damage (TOD). In the present study we sought to assess the prevalence of hyperuricemia in healthy subjects as well as the role of UA in determining TOD. We evaluated vascular, cardiac and renal TODs in the whole population as well as sub-grouped by gender.

METHODS AND RESULTS

As many as 379 blood donors participated at the present analysis. TOD was evaluated as Pulse Wave Velocity (PWV), Left Ventricular Mass Index (LVMI) and carotid Intima-Media Thickness (IMT). Hyperuricemia was defined with the classic cut-off (>7.0 in men and >6.0 mg/dL in women) but also with a most recently defined one (5.6 mg/dL for both sex). Hyperuricemia was present in 6.3% of the whole population (7.3% males, 2.8% females) considering the classic cut-off, while, with the recently identified one, it was present in 28.2% of the whole population (37.3% males, 4.7% females). Despite all the evaluated TODs significantly correlated with UA, linear multivariate regression analysis showed that none of them, except for GFR, displayed UA as a significant covariate. Similar figures were found also when both correlation and linear regression analyses were repeated in the two genders separately.

CONCLUSIONS

Hyperuricemia is an important problem also in healthy subjects and its prevalence could further increase if lower cut-off will be used. In this specific population UA is significantly associated with renal impairment while this was not the case for cardiac and vascular damage.

Is microvascular dysfunction a systemic disorder with common biomarkers found in the heart, brain, and kidneys? - A scoping review

Although microvascular dysfunction (MVD) has been well characterized in individual organs as different disease entities, clinical evidence is mounting in support of an underlying systemic process. To address this hypothesis, we systematically searched PubMed and Medline for studies in adults published between 2014 and 2019 that measured blood biomarkers of MVD in three vital organs i.e. brain, heart, and the kidney. Of the 9706 unique articles 321 met the criteria, reporting 49 biomarkers of which 16 were common to the three organs. Endothelial dysfunction, inflammation including reactive oxidation, immune activation, and coagulation were the commonly recognized pathways. Triglyceride, C-reactive protein, Cystatin C, homocysteine, uric acid, IL-6, NT-proBNP, thrombomodulin, von Willebrand Factor, and uric acid were increased in MVD of all three organs. In contrast, vitamin D was decreased. Adiponectin, asymmetric dimethylarginine, total cholesterol, high-density and low-density cholesterol were found to be variably increased or decreased in studies. We review the pathways underlying MVD in the three organs and summarize evidence supporting its systemic nature. This scoping review informs clinicians and researchers in the multi-system manifestation of MVD. Future work should focus on longitudinal investigations to evaluate the multi-system involvement of this disease.

High serum uric acid is associated with increased arterial stiffness in hypertension

Serum uric acid level has been found to be associated with cerebrovascular diseases. However, whether serum uric acid level is a risk factor for arterial stiffness in the hypertension population is unclear. This study was designed to determine the relationship between serum uric acid level and arterial stiffness in the hypertension population. A total of 10450 participants were evaluated for the risk of arterial stiffness. Brachial-ankle pulse wave velocity (baPWV) was assessed, and high baPWV was determined as the highest quartile of baPWV values in a sex-specific manner. We evaluated the association between serum uric acid level and baPWV through multivariate-adjusted linear and logistic regression analyses. There was a significant difference on high baPWV between patients with quartiles of serum uric acid level in females and males (p<0.01), respectively. The odds ratios (95% CI) of the highest baPWV quartile across the sex-specific serum uric acid level were 1.0, 1.71 (1.35, 2.17), 1.75 (1.38, 2.23), and 1.95 (1.51, 2.51) in female, and 1.0, 1.33 (1.09, 1.64), 1.36 (1.11, 1.67), and 1.67 (1.36, 2.04) in male after adjusting for potential confounders. In conclusion, serum uric acid level could be considered as an important risk factor for arterial stiffness in Chinese hypertension population.

Asymmetric dimethylarginine predicts impaired epicardial coronary vasomotion in patients with angina in the absence of obstructive coronary artery disease

BACKGROUND

Impaired epicardial coronary vasomotion is a potential mechanism of angina and a predictor of adverse cardiovascular outcomes in patients without angiographic evidence of obstructive coronary artery disease (CAD). We sought to evaluate the association of asymmetric dimethylarginine (ADMA)-a marker of nitric oxide-mediated vascular dysfunction-with epicardial coronary vasomotor dysfunction in this select population.

METHODS

Invasive testing for epicardial vasomotor dysfunction was performed using intracoronary acetylcholine in the left anterior descending coronary artery. Impaired vasomotor response was defined as a luminal constriction of >20% on quantitative coronary angiography. Plasma ADMA levels were measured using high performance liquid chromatography. A robust multivariate linear mixed-effect model approach and Akaike information criterion were used to determine predictors of vasomotor dysfunction.

RESULTS

In 191 patients with angina in the absence of obstructive CAD, abnormal epicardial vasomotion was observed in 137 (71.7%) patients. Median ADMA rose as the extent of impairment progressed: none (0.48 [0.44-0.59] μM), any (0.51 [0.46-0.60] μM, p = 0.12), focal (0.54 [0.49,0.61] μM, p = 0.17), and diffuse (0.55 [0.49,0.63] μM, p = 0.02). In unadjusted analysis, ADMA was highly predictive of vasomotor dysfunction (χ²=15.1, p = 0.002). Notably, ADMA remained a significant predictor even after adjusting for other factors in the best fit model (χ²=10.0, p = 0.02).

CONCLUSIONS

ADMA is an independent predictor of epicardial coronary vasomotor dysfunction in patients with angina in the absence of obstructive CAD. These data support a very early mechanistic role of ADMA in the continuum of atherosclerotic heart disease.

Pulse wave velocity progression over a medium-term follow-up in hypertensives: Focus on uric acid

The role of uric acid (UA) on the arterial stiffness progression has been evaluated only in three studies. Our aim was to evaluate its role as a possible determinant of the pulse wave velocity (PWV) progression over a 3.7 ± 0.5 years follow-up period in hypertensive patients. Specific sex analysis was done due to the well-known sex interaction with UA levels. We enrolled 422 consecutive hypertensive outpatients. At baseline anamnestic, blood pressure (BP) and laboratory data as well as PWV were assessed. PWV was performed again at follow-up examination. Hyperuricemia was defined as a UA > 6 mg/dL for women and > 7 mg/dL for men. Baseline age was 53.2 ± 13 years, 58% were males, systolic and diastolic BP (SBP/DBP) 141.7 ± 17.7/86.8 ± 10.8 mm Hg, UA 5.2 ± 1.4 mg/dL, and PWV 8.5 ± 1.9 m/s. At follow-up, despite better BP values (-8.5 ± 24.6 for SBP and -7.5 ± 15.4 for DBP), PWV increases to 9.1 ± 2.3 m/s (P < 0.001) with mean ΔPWV of+ 0.5 ± 2.2 m/s. A total of 61 patients were hyperuricemic (14.4%), and they present higher PWV baseline (9.0 ± 2.5 vs 8.5 ± 1.8 m/s, P = 0.03) without significant differences in ΔPWV. Hyperuricemic female (6.2%, 11 patients) presents higher baseline PWV without significant differences in ΔPWV. No differences were found in arterial stiffness in hyperuricemic males (20.4%, 50 patients). UA showed association with baseline and ΔPWV in the whole population but it loses statistical significance at the linear regression model. Same figures were also for sex analysis. Our findings provide evidence that baseline UA levels are not determinants of PWV progression over a median follow-up of 3.8 years' in hypertensive patients.

Pathophysiology and treatment of cardiovascular disease in pediatric chronic kidney disease

Life expectancy in patients with all stages of chronic kidney disease (CKD) falls far short of that in the general population. Cardiovascular disease is the leading cause of mortality in pediatric patients with CKD. In contrast to the intimal atherosclerotic lesions that characterize cardiovascular disease in the general population, vascular endothelial dysfunction, medial arterial calcification, and cardiac dysfunction contribute to cardiovascular pathological conditions in CKD. The pathogenesis of these lesions, the origins of which can be identified in the absence of traditional cardiovascular risk factors, is incompletely understood. CKD-mediated vascular calcification in CKD is characterized by a transition of vascular smooth muscle cells to an osteoblast-like phenotype and altered bone and mineral metabolism are strongly linked to progressive cardiovascular disease in this population. Renal osteodystrophy therapies, including phosphate binders, vitamin D analogs, and calcimimetics, have an impact on the progression of cardiovascular disease. However, cardiovascular disease has its origins before the development of secondary hyperparathyroidism, and optimal therapeutic regimens that minimize cardiac dysfunction, vascular calcification, and early mortality remain to be defined.

Sex-related relationships between uric acid and target organ damage in hypertension

Heterogeneous results have been obtained in the relationship between serum uric acid (SUA) and target organ damage (TOD) in patients with hypertension. Clinic blood pressure, SUA, and cardiac, arterial (carotid and aortic), and renal TOD were assessed in 762 consecutive patients with hypertension. Hyperuricemia was defined as an SUA >7.0 in men and >6.0 mg/dL in women. Men with hyperuricemia compared with those with normal SUA showed lower estimated glomerular filtration rates and E/A ratios and a higher prevalence of carotid plaques. Women with hyperuricemia showed lower estimated glomerular filtration rates and E/A ratios and a higher intima-media thickness. Except for pulse wave velocity, all TODs significantly correlated with SUA. However, at multivariate analysis, only estimated glomerular filtration rate was significantly determined by SUA. Our data provide evidence on the role of SUA in the development of TOD only in the case of renal alteration. It is likely that SUA may indirectly act on the other TODs through the increase in blood pressure and the decrease in glomerular filtration rate.

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.

Associations Between Hyperuricemia and Chronic Kidney Disease: A Review

CONTEXT

In human beings, uric acid is the poorly soluble circulating end product of the purine nucleotide metabolism. A reduction in the glomerular filtration rate (GFR) contributes to hyperuricemia, which is frequently observed in patients with chronic kidney disease (CKD).

EVIDENCE ACQUISITION

Hyperuricemia is defined as a serum uric acid level > 7.0 mg/dL in males and > 6.0 mg/dL in females, while CKD is defined as kidney damage or a GFR < 60 mL/min/1.73 m(2) for 3 months or more, irrespective of the cause. Hyperuricemia is common in CKD and may occur because of decreased excretion, increased production, or a combination of both mechanisms.

RESULTS

The causes for hyperuricemia in overproducers may be either exogenous or endogenous. CKD has become a global public health problem because of its high prevalence and the accompanying increase in the risk of end-stage renal disease, cardiovascular disease, and premature death. The most common risk factors for CKD are obesity and the metabolic syndrome, which is strongly associated with hyperuricemia probably as a consequence of insulin resistance and the effects of insulin to reduce the urinary urate excretion. For recurring bouts of hyperuricemia or gout, patients should have a blood test and joint fluid test to determine whether the medication taken is effective. Interventional studies are a useful clinical research tool in clarifying the role of hyperuricemia in CKD.

CONCLUSIONS

Although many evidence-based studies have suggested that uric acid itself may harm patients with CKD by increasing inflammation and CKD progression, the issue is still a matter of controversy. Special attention should be paid to specific contraindications to certain drugs and the possibility of infectious arthritis.

Synergism between asymmetric dimethylarginine (ADMA) and a genetic marker of uric acid in CKD progression

BACKGROUND & AIMS

We have recently reported that a polymorphism (rs734553) in a major urate transporter gene (GLUT9) is a strong predictor of incident renal events in stage 2-5 CKD patients implying that life-time exposure to high uric acid levels may be causally implicated in CKD progression. Since disturbed NO bioavailability is a major pathway whereby high uric may cause renal damage, we tested the interaction between the major endogenous inhibitor of NO synthase, asymmetric-dimethylargine (ADMA), and the rs734553 polymorphism for CKD progression in the same cohort.

METHODS & RESULTS

Over a 29 ± 11 months follow-up the risk for incident renal events was higher in patients harboring the risk allele of the polymorphism (T) as compared to those without the risk allele (HR: 2.35, 95% CI: 1.25-4.42, P = 0.008) (p = 0.01). Similarly, patients with ADMA > median value had an increased risk for the same outcome (HR: 1.37, 95% CI: 1.06-1.76, P = 0.016). Interaction analysis showed a strong amplification by ADMA of the risk for renal events associated to the T allele because in adjusted (P = 0.016) and bootstrapping validated (P = 0.020) analyses the risk excess associated to this allele was progressively higher across increasing ADMA levels.

CONCLUSIONS

The rs734553 polymorphism, the strongest genetic marker of uric acid levels discovered so far, interacts with ADMA in determining the risk for CKD progression in CKD patients. This synergic interaction conforms to biological knowledge indicating that disturbed NO bio-availability is a critical pathway whereby life time exposure to high uric acid may engender renal damage.

Relationship between serum uric acid and serum oxidative stress markers in the Japanese general population

BACKGROUND

Increased production of reactive oxygen species is a condition that is associated with, and plays a role in the progression of, various disorders such as hypertension, atherosclerosis, and diabetes.

PURPOSE

To assess in vivo oxidative stress levels and antioxidant potential and to analyze the relationship with serum uric acid (UA) levels.

METHODS AND RESULTS

Oxidative stress levels (derivatives of reactive oxygen metabolites, d-ROMs) and antioxidant potential (biological antioxidant potential, BAP) were measured in individuals who underwent a general health screening test, and data were analyzed from 8,025 individuals (2,953 women and 5,072 men) who were free from UA-lowering medication. Higher serum UA levels were associated with increased levels of d-ROMs in both genders, and this trend was more prominent in women. In addition, higher UA levels were also associated with higher BAP in both genders, although the dose dependence was not apparent in men. These associations remained statistically significant after adjusting for age, blood pressure, renal function, albuminuria, C-reactive protein, and insulin resistance index.

CONCLUSIONS

In individuals who underwent general health screening, serum UA levels were positively associated with both d-ROMs and BAP levels. Whether lowering of UA by lifestyle modification or by medication alters d-ROM/BAP levels awaits further investigations. .

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.

Prevalence of hyperuricemia and the relationship between serum uric acid and metabolic syndrome in the Asian Mongolian area

AIM

To investigate the prevalence of hyperuricemia and the association between the serum uric aci (SUA) levels and incidence of metabolic syndrome (MetS) in the Mongolian area of China.

METHODS

This cross-sectional survey was based on a population of 1,426 subjects (809 men and 617 women) 20-80 years of age who were recruited from Inner Mongolia, China. Metabolic and anthropometric indicators were measured according to standard methods. Hyperuricemia was defined as an SUA level of ≥7.0 mg/dL for men and ≥6.0 mg/dL for women. MetS was diagnosed based on the consensus criteria released in 2009 from a joint collaboration organization.

RESULTS

The prevalence of hyperuricemia was 17.7% in men and 5.2% in women. The prevalence of MetS in men was higher than that observed in women(36.7% vs. 17.8%). Waist circumference, BMI and the level of triglycerides were most strongly correlated with the SUA level in both sexes. Men with hyperuricemia had an increased risk of MetS [OR(95%CI)=2.95(2.00-4.35)], while men with a "normal" SUA level(＞5.0 mg/dL and ＜6.3 mg/dL) had a higher risk of MetS, central obesity and hypertriglyceridemia than men in the lower level group (≤5 mg/dL). Women with a higher SUA level(≥4.3 mg/dL) had an increased risk of MetS, central obesity, hypertriglyceridemia and hypertension compared with women in the lowest tertile SUA group (≤3.5 mg/dL).

CONCLUSIONS

The SUA level is significantly associated with various metabolic indicators. In this study, waist circumference and the level of triglycerides were most strongly correlated with the SUA level in both sexes. Individuals with a normal level of SUA had an increased risk of MetS and other metabolic disorders. Further research on appropriate cut-off values for pre-hyperuricemia is expected, and the early detection of hyperuricemia is essential for the prevention of MetS.

Hypertension: what's sex got to do with it?

Hypertension is a complex and multifaceted disease, and there are well established sex differences in many aspects of blood pressure (BP) control. The intent of this review is to highlight recent work examining sex differences in the molecular mechanisms of BP control in hypertension to assess whether the "one-size-fits-all" approach to BP control is appropriate with regard to sex.

A novel metabolic balance model for describing the metabolic disruption of and interactions between cardiovascular-related markers during acute myocardial infarction

OBJECTIVE

After acute myocardial infarction (AMI), an integral evaluation of risk using multimarker approach and the understanding of the pathophysiological processes involved have recently received much attention. This study aimed to develop a model to integrally evaluate the metabolic disruption of cardiovascular-related markers and unveil their interactions after AMI.

METHODS

AMI was induced in rats by coronary artery ligation. Several cardiovascular-related markers in plasma and the heart were determined during AMI. A metabolic balance model was developed using matrix equations to assess the metabolic disturbance of, and interactions between, these markers.

RESULTS

Metabolic balance maps intuitively depicted the metabolic disruption of cardiovascular-related markers after AMI. The deviation and magnitude of the disruption were quantitatively and integrally described by φ and k (the dynamic parameter of metabolic balance disruption), respectively. The metabolic balance was disturbed in both the circulatory system and the heart post-AMI. All of the measured markers appeared to be interactional. Among these markers, kidney function and dimethylarginine dimethylaminohydrolase (DDAH) activity in the heart showed a potent effect on the other markers, whereas asymmetric dimethylarginine (ADMA) levels in plasma and adenosine triphosphate (ATP) contents in the heart were susceptible to the effects of the other markers.

CONCLUSION

A metabolic balance model was developed to integrally evaluate the disruption of cardiovascular-related markers after AMI, which proposes a new method for evaluating the disease state post-AMI using a multimarker approach. The unveiled interactions between these cardiovascular-related markers are helpful in understanding the pathophysiological processes.

Relationship between red cell distribution width and stroke in patients with stable chronic heart failure: a propensity score matching analysis

AIM

We aimed to investigate the association between baseline red cell distribution width (RDW) level and the risk of stroke in patients with heart failure (HF).

METHODS

A total of 153 consecutive patients with HF (New York Heart Association [NYHA] I-III and left ventricular ejection fraction of <40%) were included in this prospective study. All the patients were followed up for 1 year, and during this period the cerebrovascular disease was questioned.

RESULTS

In matched population, using propensity score matching comparing patients with HF having stroke with patients without stroke, we found significantly increased basal RDW and serum uric acid. The receiver-operating characteristic curves of RDW for predicting stroke are performed. An RDW ≥ 15.2% measured on admission had 87% sensitivity and 74% specificity in predicting stroke in patients with HF (area under the curve: 0.923, 95% confidence interval: 0.852-0.994, P < .001).

CONCLUSION

In conclusion, this study demonstrated that RDW may be important hematological indices for stroke in patients with HF using propensity score analysis.

Serum levels of asymmetric dimethylarginine and apelin as potential markers of vascular endothelial dysfunction in early rheumatoid arthritis

Objectives. Impaired endothelial function represents the early stage of atherosclerosis, which is typically associated with systemic inflammatory diseases like rheumatoid arthritis (RA). As modulators of endothelial nitric oxide synthase expression, asymmetric-dimethylarginine (ADMA) and apelin might be measured in the blood of RA patients to detect early atherosclerotic changes. We conducted a prospective, case-control study to investigate serum ADMA and apelin profiles of patients with early-stage RA (ERA) before and after disease-modifying antirheumatic drug (DMARD) therapy. Methods. We enrolled 20 consecutively diagnosed, treatment-naïve patients with ERA and 20 matched healthy controls. Serum ADMA and apelin levels and the 28-joint disease activity scores (DAS28) were assessed before and after 12 months of DMARDs treatment. All patients underwent ultrasonographic assessment for intima-media tickness (IMT) evaluation. Results. In the ERA group, ADMA serum levels were significantly higher than controls at baseline (P = 0.007) and significantly decreased after treatment (P = 0.012 versus controls). Baseline serum apelin levels were significantly decreased in this group (P = 0.0001 versus controls), but they were not significantly altered by treatment. IMT did not show significant changes. Conclusions. ERA is associated with alterations of serum ADMA and apelin levels, which might be used as biomarkers to detect early endothelial dysfunction in these patients.

Uric acid does not affect the prevalence and extent of coronary artery disease. Results from a prospective study

BACKGROUND

Hyperuricemia may be involved in the atherosclerotic process due to endothelial dysfunction and facilitation of smooth muscle cell proliferation. However, debates still exist on the independent role of hyperuricemia, due to its association with several cardiovascular risk factors, such as hypertension, hyperlipidemia, obesity and insulin resistance. Thus, the aim of the current study was to investigate in a consecutive cohort of patients undergoing coronary angiography whether hyperuricemia is associated with the extent of coronary artery disease.

METHODS AND RESULTS

Our population is represented by a total of 1901 consecutive patients undergoing coronary angiography between May 2007 and January 2010 at the Azienda Ospedaliera "Maggiore della Carità", Novara, Italy. We additionally evaluated platelet aggregation by PFA-100 (Collagen/Epinefrine) and Multiplate. Quantitative coronary angiography and analysis of IMT were performed by experienced cardiologists who had no knowledge of the patients' clinical information. Higher uric acid was associated with advanced age, larger prevalence of male gender, diabetes, renal insufficiency, hypertension, previous CABG and MI, but with a lower prevalence of family history of CAD. Patients with high uric acid were more often on calcium antagonists, ace-inhibitors, angiotensin receptor antagonists, and, as expected, on diuretics. A significant relationship was observed between uric acid and the prevalence (OR [95% CI] = 1.18 [1.04-1.32], p = 0.01) and severity of CAD (OR [95% CI] = 1.17 [1.03-1.33], p = 0.014). However, the relationship disappeared after correction for baseline confounding factors for both prevalence (OR [95% CI] = 1.06 [0.93-1.21], p = 0.35) and extent of CAD (OR [95% CI] = 1.0 [0.87-1.15], p = 0.96). No relationship was observed between acid uric and IMT (p = 0.73) analyzed in 359 consecutive patients. Finally, there was no relationship between uric acid and platelet aggregation in patients with or without aspirin therapy, as measured by PFA-100 and Multiplate.

CONCLUSIONS

Our study showed that uric acid is not associated with platelet aggregation, the extent of coronary artery disease and IMT. Thus, waiting for the results of additional large studies, uric acid may not be considered as a risk factor for coronary artery disease, and its reduction by specific therapies may not be recommended to prevent coronary artery disease and atherosclerosis.

Uric acid and chronic kidney disease: new understanding of an old problem

Although an elevation of serum uric acid level is often associated with chronic kidney disease (CKD), it remains controversial whether hyperuricemia per se is a true risk factor for the development or aggravation of CKD. Recent epidemiologic studies in healthy populations or in subjects with established kidney disease have reported the independent role of uric acid in lowering glomerular filtration rate and increasing the risk for new-onset kidney disease. Furthermore, lowering uric acid in patients with established renal disease has been reported to stabilize renal function independent of other confounders, suggesting a causative role of elevated uric acid in progression of CKD, rather than as an incidental finding related to CKD severity. In this manuscript we will discuss the potential role of uric acid in the development and aggravation of CKD based on epidemiologic, clinical and experimental studies. Given the worldwide epidemic of CKD, the importance of identifying modifiable risk factors of CKD, and the clinical implication of hyperuricemia in CKD, we propose large randomized clinical trials to investigate whether uric acid-lowering therapy can slow the progression of CKD.

Association of serum uric acid level with aortic stiffness and arterial wave reflections in newly diagnosed, never-treated hypertension

BACKGROUND

Serum uric acid (UA) plays a key role in the development and progression of hypertension. We investigated the association of UA levels and indices of arterial function in a cohort of newly diagnosed, never-treated hypertensive subjects.

METHODS

One thousand two hundred and twenty-five patients with a new diagnosis of mild to moderate arterial hypertension for which they had never received treatment were enrolled in the study (mean age 52.9 years, 728 men). Serum UA, carotid-femoral pulse-wave velocity (cfPWV), an index of aortic stiffness and augmentation index (AIx), a composite marker of wave reflections and arterial stiffness were measured.

RESULTS

In univariable analysis, UA levels correlated with cfPWV (r = 0.23, P < 0.001) and AIx (r = -0.24, P < 0.001). In multiple linear regression analysis, an independent positive association of cfPWV with UA levels was observed after adjusting for confounders (standardized regression coefficient β = 0.169, P < 0.001, adjusted R² = 0.402), indicating an increase in aortic stiffness with higher values of UA. In contrast, an independent negative association of AIx with UA levels was observed after adjusting for confounders (standardized regression coefficient β = -0.064, P = 0.011, adjusted R² = 0.557), indicating a decrease in wave reflections with higher values of UA. In gender-specific analyses, UA positively correlated with cfPWV in both genders, whereas a negative correlation with AIx existed only in females.

CONCLUSIONS

Serum UA levels are independently associated with aortic stiffening and wave reflections in never-treated hypertensives. Future studies are warranted in order to explore its exact role on arterial function in the hypertensive setting.

Statin treatment decreased serum asymmetric dimethylarginine (ADMA) levels in ischemic stroke patients

AIM

It remains unclear whether the decrease in the ADMA level associated with statin treatment results from the LDL-C-lowering effect or the pleiotropic effects of statins. A prospective, controlled study was conducted to examine whether statin treatment affects serum ADMA concentrations in ischemic stroke patients.

METHODS

Consecutive outpatients with non-cardiogenic ischemic stroke who had never been treated with statins and whose LDL-cholesterol level was higher than 140 mg/dL were enrolled and compared with control patients whose LDL-cholesterol level was lower than 140 mg/dL. Overall, 114 patients were enrolled in the study (56 and 58 in statin-treated and non-statin-treated groups, respectively). Patients in the statin group were treated with pravastatin 10 mg/day (n=15), fluvastatin 20 mg/day (n=14), pitavastatin 1 mg/day (n=14), or atorvastatin 10 mg/day (n=13).

RESULTS

The serum ADMA concentration and LDL-C level were significantly decreased by statin treatment (p=0.003 and p< 0.001, respectively), and the ADMA concentration in subjects treated with statins was significantly lower than that of the control (p=0.028). Multiple linear regression analysis showed that age (β=0.26, p< 0.05) and statin use (β=-0.20, p< 0.05) were independently associated with the ADMA level.

CONCLUSIONS

A significant relation between statin treatment and decreased levels of ADMA was demonstrated in ischemic stroke patients with an adequately controlled lipid profile, suggesting the statin treatment might prevent atherosclerotic disease in ischemic stroke patients through suppression of ADMA concentration.