Release of platelet constituents by monosodium urate crystals

Serum Uric Acid Levels Associated with Outcomes of Neurodegenerative Disorders and Brain Health: Findings from the UK Biobank

BACKGROUND

The relationship between serum uric acid (SUA) levels and brain-related health remains uncertain.

OBJECTIVES

This study aimed to investigate the relationship between SUA levels and some neurodegenerative disorders and brain structure.

DESIGN

A longitudinal study.

SETTING AND PARTICIPANTS

384,517 participants who did not have stroke, dementia, and Parkinsonism, with complete urate testes and covariates were included.

MEASUREMENTS

Cox proportional hazards models, competing risk models, and restricted cubic spine models were applied.

RESULTS

During the median follow-up time of 12.7 years (interquartile range [IQR]:12.0, 13.5), 7821 (2.0%) participants developed stroke, 5103 (1.3%) participants developed dementia, and 2341 (0.6%) participants developed Parkinsonism. Nonlinear relationships were identified between SUA levels and stroke (J-shaped), dementia, and Parkinsonism (U-shaped). SUA levels of 4.2 mg/dl, 6.4 mg/dl, and 6.6 mg/dl yielded the lowest risk of stroke, dementia, and Parkinsonism, respectively. Besides, we found high SUA levels reduced the volumes of total brain, grey matter, white matter, grey matter in the hippocampus, and hippocampus, but increased lateral-ventricle volume. Inflammation accounted for 9.1% and 10.0% in the association of SUA with stroke and lateral-ventricle volume.

CONCLUSIONS

Lower SUA levels increased the risk of Parkinsonism, while both lower and higher SUA levels were positively associated with increased risk of stroke and dementia. Moreover, high SUA levels reduced brain structure volumes. Our findings suggest the association between SUA levels and brain-related disorders and highlight the importance of SUA management.

Hyperuricemia: An Intriguing Connection to Metabolic Syndrome, Diabetes, Kidney Disease, and Hypertension

PURPOSE OF THE REVIEW

Our review explores the epidemiology, physiology, and clinical data surrounding the connection between hyperuricemia and metabolic syndrome, chronic kidney disease, and hypertension.

RECENT FINDINGS

Compelling physiologic mechanisms have been proposed to explain a causal relationship between hyperuricemia and metabolic syndrome, chronic kidney disease, and hypertension but clinical studies have given mixed results in terms of whether intervening with hyperuricemia using urate-lowering therapy has any beneficial effects for patients with these conditions. Despite the large amount of research already put into this topic, more randomized placebo-controlled trials are needed to more firmly establish whether a cause-effect relationship exists and whether lowering uric acid levels in patients with these conditions is beneficial.

Integrating network pharmacology and renal metabonomics to reveal the protective mechanism of resveratrol on gouty nephropathy

Resveratrol (Res) has been demonstrated to have beneficial effects on gouty nephropathy (GN). However, the mechanisms of Res on GN remain unclear. This study aimed to investigate the mechanisms of Res on GN. In this study, network pharmacology technology was used to predict the Res targets in the prevention and treatment of GN. Renal metabonomics was used to identify differential metabolites in kidney tissue of GN model rats. Finally, molecular docking technology was used to verify the binding ability of Res to key targets. Metabonomics analysis showed that 24 potentially important metabolites were involved in the prevention and treatment of GN with Res. After exposure to Res, metabolite levels normalized. The network pharmacology analysis showed that 24 key targets were involved in the prevention and treatment of GN disease. According to the metabolite-gene network diagram, we identified two core genes, PTGS1 and PTGS2, and found that both were involved in the arachidonic acid metabolism pathway. Molecular docking further verified the affinity of Res binding to PTGS1 and PTGS2. In conclusion, the mechanism of Res against GN may be the regulation of arachidonic acid metabolism through the regulation of PTGS 1 and PTGS 2.

Hyperuricemia is associated with heart failure readmission in patients with heart failure and preserved ejection fraction-an observational study in Chinese

BACKGROUND AND AIMS

This study aimed to explore the association between hyperuricemia and heart failure (HF) readmission in HF patients with preserved ejection fraction (HFpEF) because the impact of hyperuricemia on the prognosis of these patients has not been fully understood.

METHODS AND RESULTS

This retrospective observational study included 538 hospitalized patients diagnosed with HFpEF. A total of 57.6 % of patients with HFpEF suffered from hyperuricemia (serum uric acid (SUA) was >7 mg/dL in men and >6 mg/dL in women). Compared to those without hyperuricemia, patients with hyperuricemia were more likely to be female (62.6 % vs. 53.9 %, p = 0.044) and older (78.0 ± 8.4 vs. 75.9 ± 9.0 years, p = 0.008). Our Cox analysis revealed that SUA level (hazard ratio (HR) = 1.158, 95 % confidence interval (CI): 1.087-1.234, p<0.001) and hyperuricemia (HR = 1.846, 95 % CI: 1.308-2.606, p<0.001) were associated with HF readmission in patients with HFpEF, respectively. Kaplan-Meier analysis showed that patients with hyperuricemia had a significantly worse prognosis (p<0.001). The receiver operating characteristic analysis revealed that the area under the ROC curve of SUA for predicting HF readmission was 0.6276 (95 % CI: 0.5763-0.6790) and a designated cut-off value of 7.53 mg/dL.

CONCLUSIONS

Hyperuricemia is a common comorbidity among patients with HFpEF. Moreover, SUA level and hyperuricemia have been shown to be associated with HF readmission. Therefore, it is meaningful to monitor SUA levels in patients with HFpEF during the whole treatment period of HF. Whereas, whether intervention of hyperuricemia could benefit patients with HFpEF needs further studies.

A cross-sectional analysis of the relationship between ischemic stroke and uric acid in young people in highland areas

Objective

To investigate the relationship between serum uric acid (SUA) levels and ischemic stroke in young patients in the Ganzi Tibetan plateau area.

Methods

A cross-sectional survey was undertaken from January 2020 to June 2023 involving young patients (age: 15-45 years) diagnosed with ischemic stroke. The survey was conducted at the Department of Internal Medicine of the People's Hospital of Derong County, Ganzi Prefecture. The participants underwent a comprehensive assessment, including questionnaire surveys, physical examinations, laboratory tests, and head computed tomography (CT) examinations. Based on the tertiles of serum uric acid (SUA) levels, the patients were stratified into three groups. Furthermore, stroke severity was classified into mild (1-4 points), moderate (5-15 points), and severe (>15 points) categories using the National Institute of Health Stroke Scale.

Results

The severe stroke group exhibited higher levels of age, glucose, systolic blood pressure, serum triglyceride, low-density lipoprotein cholesterol, and serum uric acid (SUA) compared to the mild stroke group (P < 0.05). Furthermore, the likelihood of male sex, advanced age, smoking, and a family history of stroke, diabetes mellitus, and heart disease were significantly elevated in the severe stroke group compared to the moderate stroke group (P < 0.05). Multivariate logistic regression analysis conducted on young adults residing in highland areas revealed a significant association between SUA levels and the risk of stroke.

Conclusion

Elevated SUA levels serve as a distinct risk factor for the development of a major stroke in young patients in highland areas. At SUA levels of 320.56 mol/L, the risk of a moderate-to-severe stroke is noticeably elevated.

The impact of platelet-to-lymphocyte ratio on clinical outcomes in heart failure: a systematic review and meta-analysis

BACKGROUND

Inflammation has been suggested to play a role in heart failure (HF) pathogenesis. However, the role of platelet-to-lymphocyte ratio (PLR), as a novel biomarker, to assess HF prognosis needs to be investigated. We sought to evaluate the impact of PLR on HF clinical outcomes.

METHODS

English-published records in PubMed/Medline, Scopus, and Web-of-science databases were screened until December 2023. Relevant articles evaluated PLR with clinical outcomes (including mortality, rehospitalization, HF worsening, and HF detection) were recruited, with PLR difference analysis based on death/survival status in total and HF with reduced ejection fraction (HFrEF) patients.

RESULTS

In total, 21 articles (n = 13,924) were selected. The total mean age was 70.36 ± 12.88 years (males: 61.72%). Mean PLR was 165.54 [95% confidence interval (CI): 154.69-176.38]. In total, 18 articles (n = 10,084) reported mortality [either follow-up (PLR: 162.55, 95% CI: 149.35-175.75) or in-hospital (PLR: 192.83, 95% CI: 150.06-235.61) death rate] and the mean PLR was 166.68 (95% CI: 154.87-178.50). Further analysis revealed PLR was significantly lower in survived HF patients rather than deceased group (152.34, 95% CI: 134.01-170.68 versus 194.73, 95% CI: 175.60-213.85, standard mean difference: -0.592, 95% CI: -0.857 to -0.326, p < 0.001). A similar trend was observed for HFrEF patients. PLR failed to show any association with mortality risk (hazard ratio: 1.02, 95% CI: 0.99-1.05, p = 0.289). Analysis of other aforementioned outcomes was not possible due to the presence of few studies of interest.

CONCLUSION

PLR should be used with caution for prognosis assessment in HF sufferers and other studies are necessary to explore the exact association.

The effect of allopurinol on cardiovascular outcomes in patients with type 2 diabetes: a systematic review

BACKGROUND

Cardiovascular disease (CVD) remains the main cause of death in patients with type 2 diabetes (T2D). Although hyperuricemia has been associated with multiple CV complications, it is not officially recognized as a target parameter for CVD risk reduction.

AIM

To systematically review the literature in order to determine whether treating hyperuricemia with allopurinol in patients with T2D reduces CVD risk.

METHODS

A thorough literature search in the PubMed, CENTRAL, and EMBASE databases from inception to August 2022 was performed. After application of selection criteria, 6 appropriate studies were identified.

RESULTS

Detailed analysis of the data derived indicated that there is an association between allopurinol treatment and CV benefits, resulting in a reduced risk of CVD events and mortality rates. This association can be attributed mainly to the reduction of inflammation and oxidative burden, as well as to the improvement of glycemic and lipid profiles.

CONCLUSIONS

This systematic review provides evidence that allopurinol may reduce CVD risk in patients with T2D. Randomized, placebo-controlled trials should be performed in order to confirm these findings and identify specific subgroups of patients who will benefit most.

Serum Uric Acid Concentration in Patients with Cerebrovascular Disease (Ischemic Stroke and Vascular Dementia)

Introduction:

Significance of serum uric acid (UA) in cerebrovascular disease still remains controversial. UA is most abundant natural antioxidant in human plasma. Its antioxidant properties might protect against free radical damage, thereby reducing the risk of oxidative stress-related cognitive impairment and dementia.

Aim:

In our investigation, we determine the level of UA in 100 male patients diagnosed with the first ischemic brain stroke (blood samples were collected during the acute phase and post-acute phase), 100 male patients diagnosed with vascular dementia and 100 male healthy volunteers (control group).

Methods:

UA was determined using DIMENSION LxR automatic analyzer. Measurement of UA concentration was based on an enzymatic method (range 208-428 μmol/L).

Results:

The prevalence of hyperuricemia among ischemic stroke and vascular dementia patients was 30% and 8%, respectively. Serum UA concentration was higher 7 and 14 days after the stroke compared to the acute phase (24-48 hours after hospitalization) and these concentrations were significantly higher than those measured in the control group. UA levels measured at 24-48 hours after the first symptoms of ischemic stroke were strongly correlated with those measured after 7 days of treatment (r = 0.79, p = 0.001) or after 14 days (r = 0.839, p = 0.0049). No significant differences were found between ischemic stroke and vascular dementia groups.

Conclusion:

UA concentrations were higher in ischemic stroke and vascular dementia groups than in controls. UA increase may reflect vascular atherosclerosis and tissue hypoxia. UA monitoring in patients with cerebrovascular disease is essential, because UA is more harmful than protective.

Temporal relationship between body mass index and uric acid and their joint impact on blood pressure in children and adults: the Bogalusa Heart Study

OBJECTIVE

This study aimed to examine the temporal relationship between body mass index (BMI) and uric acid (UA), and their joint effect on blood pressure (BP) in children and adults.

METHODS

The longitudinal cohorts for temporal relationship analyses consisted of 564 and 911 subjects examined twice 5-14 years apart from childhood to adulthood. The cross-sectional cohorts for mediation analyses consisted of 3102 children and 3402 nondiabetic adults. Cross-lagged panel analysis models were used to examine the temporal relationship between BMI and UA, and mediation analysis models the mediation effect of UA on the BMI-BP association.

RESULTS

After adjusting for age, race, sex and follow-up years in children, and additionally smoking and alcohol drinking in adults, the path coefficients (standardized regression coefficients) from baseline BMI to follow-up UA (0.145 in children and 0.068 in adults) were significant, but the path coefficients from baseline UA to follow-up BMI (0.011 in children and 0.016 in adults) were not. In mediation analyses, indirect effects through UA on the BMI-systolic BP association were estimated at 0.028 (mediation effect = 8.8%) in children and 0.033 (mediation effect = 13.5%) in adults (P < 0.001 for both). Direct effects of BMI on systolic BP (0.289 in children and 0.212 in adults) were significant. The mediation effect parameters did not differ significantly between Blacks and Whites.

CONCLUSIONS

Changes in BMI precede alterations in UA, and the BMI-BP association is in part mediated through BMI-related increase in UA both in children and in adults. These findings have implications for addressing mechanisms of obesity hypertension beginning in early life.

Impact of uric acid on immature platelet fraction in patients undergoing percutaneous coronary intervention

INTRODUCTION

Reticulated platelets have been involved in the pathophysiology of coronary artery disease (CAD). Immature platelet fraction (IPF) allows their measurement in daily clinical practice, although the factors conditioning their elevation are still largely unexplored. Serum uric acid (SUA) is the end product of purine metabolism, displaying a pro-oxidant and pro-inflammatory action and increasing the cardiovascular risk. The aim of our study was to investigate the impact of SUA on IPF levels in patients undergoing percutaneous coronary intervention (PCI), and their relationship with CAD.

METHODS

We enrolled a cohort of consecutive patients undergoing coronary angiography in a single center. Hyperuricemia was defined by SUA ≥ 6.5 mg/dl. Significant CAD was defined as at least 1 vessel stenosis >50%, while severe CAD was defined as left main and/or three-vessel disease. IPF was measured at admission by routine blood cells count (A Sysmex XE-2100).

RESULTS

We included in our study 2217 patients, of whom 544 had high levels of SUA, while 1673 had normal levels. Hyperuricemics were older, with higher percentage of renal failure, hypertension, dilated cardiomyopathy or valvular disease as indication to angiography, higher levels of creatinine and C-reactive protein (p < 0.001, respectively) when compared to normouricemics. Immature platelet fraction (IPF) was significant higher in hyperuricemic patients (3.96% vs 3.59%, p = 0.004). A progressive direct increase in the IPF values was observed in relation to SUA levels (r = 0.101, p < 0.001), although at multivariate analysis, hyperuricemia did not result as an independent predictor of IPC in 3rd tertile (adjusted OR [95%CI] = 1.21 [0.85-1.71] P = 0.288). When stratifying hyperuricemics and normouricemics according to IPF tertiles (<2.3%; 2.3-3.9%; ≥ 4%), reticulated platelets were not associated to the prevalence of CAD (SUA ≥6.5:80.9 vs 79.3% vs 78.6%, p = 0.60; SUA < 6.5: 79.3% vs 81.3% vs 78.9%, p = 0.878) or severe CAD (SUA ≥6.5: 34.9% vs 38.9% vs 35.2%, p = 0.99; SUA < 6.5: 30.4% vs 33.5% vs 34%, p = 0.192), and the results were confirmed at multivariate analysis for CAD (SUA ≥6.5: adjusted OR [95%CI] = 1.11 [0.81-1.51] P = 0.524, SUA < 6.5: adjusted OR [95%CI] = 0.89 [0.75-1.05] P = 0.170) or severe CAD (SUA ≥6.5: adjusted OR [95%CI] = 1.03 [0.81-1.31] P = 0.795; SUA < 6.5: adjusted OR [95%CI] = 1.10 [0.96-1.26] P = 0.192).

CONCLUSIONS

In the present study we found a direct relationship between SUA levels and IPF values; however, hyperuricemia did not result as an independent predictor of higher IPF tertile values. Neither in hyperuricemics nor in normouricemics higher IPF were independently associated to the prevalence of CAD or severe CAD.

Clinical relevance of serum uric acid and abdominal aortic-calcification in a national survey

Background

Hyperuricemia was often found in subjects with an elevated risk of cardiovascular disease (CVD). Abdominal aortic‐calcification (AAC) is significantly associated with subclinical atherosclerotic disease.

Hypothesis

The aim of this study is to evaluate the relationship between serum uric acid (SUA) level and AAC from a national database.

Methods

A total of 2765 eligible participants older than 40 years who received dual‐energy X‐ray absorptiometry (DXA) scans with SUA data were enrolled from the National Health and Nutrition Examination Survey (2013‐2014). The association between SUA level and AAC was analyzed using multivariate regression models for covariate adjustment.

Results

After categorizing SUA level into four quartiles, the odds ratios for the presence of subclinical atherosclerosis via contrasting the highest SUA quartile with the lowest SUA quartile were 1.876 (95% CI = 1.298‐2.711), 2.038 (95% CI = 1.303‐3.187), 1.935 (95% CI = 1.221‐3.065), and 1.956 (95% CI = 1.225‐3.124) (all, P value less than .05) in Model 1, Model 2, Model 3, and Model 4, respectively. The above relationship remained still in the fully adjusted model for the male but not female subjects. The optimal SUA cutoff value was 6.35 mg/dL for male and 5.25 mg/dL for female to predict the presence of subclinical atherosclerosis.

Conclusions

Our results explore the promising evidences that SUA level showed a positive correlation with AAC score in a dose‐response manner. These findings decisively indicated that SUA may act as a promising tool to forecast the incidence of subclinical atherosclerosis in males.

Higher levels of serum uric acid influences hepatic damage in patients with non-alcoholic fatty liver disease (NAFLD)

BACKGROUND

recent evidence suggests a causal link between serum uric acid and the metabolic syndrome, diabetes mellitus, arterial hypertension, and renal and cardiac disease. Uric acid is an endogenous danger signal and activator of the inflammasome, and has been independently associated with an increased risk of cirrhosis.

AIM AND METHODS

six hundred and thirty-four patients from the nation-wide HEPAMET registry with biopsy-proven NAFLD (53% NASH) were analyzed to determine whether hyperuricemia is related with advanced liver damage in patients with non-alcoholic fatty liver disease (NAFLD). Patients were divided into three groups according to the tertile levels of serum uric acid and gender.

RESULTS

the cohort was composed of 50% females, with a mean age of 49 years (range 19-80). Patients in the top third of serum uric acid levels were older (p = 0.017); they had a higher body mass index (p < 0.01), arterial blood pressure (p = 0.05), triglyceridemia (p = 0.012), serum creatinine (p < 0.001) and total cholesterol (p = 0.016) and lower HDL-cholesterol (p = 0.004). According to the univariate analysis, the variables associated with patients in the top third were more advanced steatosis (p = 0.02), liver fibrosis (F2-F4 vs F0-1; p = 0.011), NASH (p = 0.002) and NAS score (p = 0.05). According to the multivariate logistic regression analysis, the top third of uric acid level was independently associated with steatosis (adjusted hazard ratio 1.7; CI 95%: 1.05-2.8) and NASH (adjusted hazard ratio 1.8; CI 95%: 1.08-3.0) but not with advanced fibrosis (F2-F4) (adjusted hazard ratio 1.09; CI 95%: 0.63-1.87).

CONCLUSION

higher levels of serum uric acid were independently associated with hepatocellular steatosis and NASH in a cohort of patients with NAFLD. Serum uric acid levels warrants further evaluation as a component of the current non-invasive NAFLD scores of histopathological damage.

Serum Uric Acid Levels and Risk of Intracranial Atherosclerotic Stenosis: A Cross-Sectional Study

Elevated serum uric acid (SUA) has been reported to be associated with an increased risk of cardiovascular diseases, but the role of SUA in intracranial atherosclerosis remains unclear. To investigate the association between SUA and intracranial atherosclerotic stenosis (ICAS), we evaluated 1522 subjects (305 with ICAS, 1217 without ICAS) with magnetic resonance angiography (MRA). Subjects were classified into ten groups according to the deciles of the SUA level. The rate of ICAS reached a minimum in the seventh decile (6.0-6.3 mg/dL; reference group). After adjusting for confounding factors, multivariate logistic regression analysis demonstrated that both low SUA level (≤ 3.8 mg/dL; OR, 2.34; 95% CI, 1.29-4.39; p = 0.006) and high SUA level (≥ 7.8 mg/dL; OR, 2.10; 95% CI, 1.15-3.92; p = 0.017) conferred greater risk for ICAS. In multivariable analysis with a quadratic model which used SUA as a continuous variable, a U-shaped association between SUA and the rate of ICAS was confirmed (α > 0; p < 0.001). The estimated SUA level associated with the lowest rate of ICAS was 6.2 mg/dL. In conclusion, our findings suggest a U-shaped association between ICAS and SUA.

Effects of Uric Acid on Diabetes Mellitus and Its Chronic Complications

With the deepening of the researches on uric acid, especially in the study of metabolic diseases, uric acid has been found to be closely related to obesity, metabolic syndrome, nonalcoholic fatty liver disease, diabetes, and other metabolic diseases. Uric acid causes a series of pathophysiological changes through inflammation, oxidative stress, vascular endothelial injury, and so on and thus subsequently promotes the occurrence and development of diseases. This review confirmed the positive correlation between uric acid and diabetes mellitus and its chronic complications through the pathogenesis and clinical studies aspects.

Relationship Between Serum Uric Acid Levels and Nonalcoholic Fatty Liver Disease in Non-Obese Patients

Background and objectives: Nonalcoholic fatty liver disease (NAFLD) is associated with multiple factors such as hypertension, diabetes, dyslipidemia, obesity, and hyperuricemia. We aim to investigate the relationship between uric acid and NAFLD in a non-obese and young population. Materials and Methods: This study was performed in January 2010–2019 with a group of 367 (225 patients in the NAFLD group and 142 in the control group) patients with liver biopsy-proven NAFLD or no NAFLD. Patients with NAFLD were classified according to the percentage of steatosis as follows, group I had 1–20% and group II >20%. Demographic, clinical, and laboratory (biochemical parameters) features were collected retrospectively. Results: The mean body mass index (BMI) and age of the patients were 26.41 ± 3.42 and 32.27 ± 8.85, respectively. The BMI, homeostatic model of assessment (HOMA-IR), and uric acid (UA) values of the NAFLD group were found to be significantly higher than those of the controls. A positive correlation was found between the NAFLD stage and UA. The following factors were independently associated with NAFLD: BMI, HOMA-IR, and UA. In addition, the cut-off value of UA was 4.75 mg/dl with a sensitivity of 45.8% and a specificity of 80.3%. Conclusions: UA is a simple, non-invasive, cheap, and useful marker that may be used to predict steatosis in patients with NAFLD.

J-shaped association between serum uric acid and acute coronary syndrome in patients with essential hypertension

BACKGROUND

The prognostic value of serum uric acid (SUA) for incident acute coronary syndrome (ACS) in hypertensive subjects is uncertain. Therefore, the present study examined the association between SUA and incident ACS in a large cohort of Chinese hypertensive adults.

METHODS

This was a retrospective cohort study, which enrolled 5473 Chinese community-dwelling hypertensive patients from 1 January 2012 to 31 December 2012. Study outcomes were ACS events, and patients were followed until 31 December 2016. Cox regression analyses were conducted to determine adjusted HRs and 95% CIs for baseline SUA tertiles (low, middle and high group) and for men and women separately.

RESULTS

A total of 5473 participants were included in the analysis (median follow-up was 4.5 years). Participants were divided into tertiles based on SUA levels. During follow-up, 9 (0.49%), 14 (0.77%) and 25 (1.37%) patients developed ACS in the lowest, middle and highest tertiles, respectively. When compared with the lowest tertile of SUA, the highest tertile of SUA was associated with ACS risk in all subjects and in men and women separately (HR: 2.62, 95% CI 1.14 to 7.01, p=0.0233; 2.15, 95% CI 1.08 to 6.04, p=0.021, and 3.49, 95% CI 1.25 to 7.74, p=0.017, respectively).

CONCLUSIONS

Higher SUA levels were independently associated with an elevated risk of ACS incidence. The relationship between SUA levels and ACS in hypertensive patients was J-shaped.

High serum uric acid level is a mortality risk factor in peritoneal dialysis patients: a retrospective cohort study

Background

The results remain controversial with regards to the impact of serum uric acid on clinical outcomes from peritoneal dialysis population. The aim of our study was to investigate the influence of serum uric acid levels on mortality in peritoneal dialysis patients.

Methods

Data on 9405 peritoneal dialysis patients from the Zhejiang Renal Data system were retrospectively analyzed. All demographic and laboratory data were recorded at baseline. The study cohort was divided into quintiles according to baseline uric acid level (mg/dL): Q1 (< 6.06), Q2 (6.06–6.67), Q3 (6.68–7.27) (reference), Q4 (7.28–8.03), and Q5 (≥8.04). Hazards ratio (HR) of all-cause and cardiovascular mortality was calculated.

Results

Mean serum uric acid was 7.07 ± 1.25 mg/dL. During a median follow-up of 29.4 (range, 3.0 to 115.4) months, 1226 (13.0%) patients died, of which 515 (5.5%) died of cardiovascular events. The Kaplan-Meier survival curves showed that patients in the middle uric acid quintile (Q3: 6.68–7.27) exhibited the highest patient and cardiovascular survival rates (log-rank test P < 0.05). Multivariate Cox regression analysis showed that, using Q3 as the reference, in the fully adjusted model, a higher uric acid level (Q4: 7.28–8.03, and Q5: ≥8.04) was significantly associated with higher all-cause mortality (Model 3; Q4: HR, 1.335, 95% CI, 1.073 to 1.662, P = 0.009; Q5: HR, 1.482, 95% CI, 1.187 to 1.849, P = 0.001), but not with cardiovascular mortality. The adverse effect of higher uric acid level (≥7.28 mg/dL) on all-cause mortality was more prominent in groups such as male, hypoalbuminemia, normal weight, non-diabetes mellitus at baseline rather than in their counterparts respectively.

Conclusions

A higher uric acid level was an independent risk factor for all-cause mortality in peritoneal dialysis patients.

Electronic supplementary material

The online version of this article (10.1186/s12986-019-0379-y) contains supplementary material, which is available to authorized users.

The prognostic role of platelet-to-lymphocyte ratio in patients with acute heart failure: A cohort study

Identification of rapid, inexpensive, and reliable prognostic factors can improve survival estimation and guide healthcare in patients with acute heart failure (AHF). In this study, we aimed to determine the prognostic value of the platelet-to-lymphocyte ratio (PLR) in patients with AHF. A total of 443 patients from two hospitals met the inclusion criteria from January 2010 to December 2017. Univariate and multivariate Cox analyses were performed to determine the association of PLR with survival. All-cause mortality was analysed using the Kaplan-Meier method. The 6-month survival rate for patients according to PLR quartiles (<110.63, 110.63-139.23, 139.23-177.17, and >177.17) were 90.09%, 76.79%, 50.07%, and 37.27%, respectively (p < 0.001). Univariate analysis identified high PLR (>110.63), old age (≥73 years), smoking habit, low estimated glomerular filtration rate (<57), and high platelet count (≥198 × 10⁹/l) as poor prognostic factors for survival. In the multivariate analysis, after adjusting for confounding factors, the third (hazard ratio [HR] = 3.118, 95% confidence interval [CI] = 1.668-5.386, p < 0.001) and fourth (HR = 2.437, 95% CI = 1.302-3.653, p < 0.001) quartiles of PLR were identified as independent prognostic factors in patients with AHF. A higher PLR was associated with poor clinical outcomes in patients with AHF and might be a novel marker in AHF management.

An Inverse Relationship between Hyperuricemia and Mortality in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

Background: The results have been inconsistent with regards to the impact of uric acid (UA) on clinical outcomes both in the general population and in patients with chronic kidney disease. The aim of this study was to study the influence of serum UA levels on mortality in patients undergoing continuous ambulatory peritoneal dialysis. Methods: Data on 492 patients from a single peritoneal dialysis unit were retrospectively analyzed. The mean age of the patients was 53.5 ± 15.3 years, with 52% being female (n = 255). The concomitant comorbidities at the start of continuous ambulatory peritoneal dialysis (CAPD) encompassed diabetes mellitus (n = 179, 34.6%), hypertension (n = 419, 85.2%), and cardiovascular disease (n = 186, 37.9%). The study cohort was divided into sex-specific tertiles according to baseline UA level. A Cox proportional hazard model was used to calculate hazard ratios (HRs) of all-cause, cardiovascular, and infection-associated mortality with adjustments for demographic and laboratory data, medications, and comorbidities. Results: Multivariate Cox regression analysis showed that, using UA tertile 1 as the reference, the adjusted HR of all-cause, cardiovascular, and infection-associated mortality for tertile 3 was 0.4 (95% confidence interval (CI) 0.24⁻0.68, p = 0.001), 0.4 (95% CI 0.2⁻0.81, p = 0.01), and 0.47 (95% CI 0.19⁻1.08, p = 0.1). In the fully adjusted model, the adjusted HRs of all-cause, cardiovascular, and infection-associated mortality for each 1-mg/dL increase in UA level were 0.84 (95% CI, 0.69⁻0.9, p = 0.07), 0.79 (95% CI, 0.61⁻1.01, p = 0.06), and 0.79 (95% CI, 0.48⁻1.21, p = 0.32) for men and 0.57 (95% CI, 0.44⁻0.73, p < 0.001), 0.6 (95% CI, 0.41⁻0.87, p = 0.006), and 0.41 (95% CI, 0.26⁻0.6, p < 0.001) for women, respectively. Conclusions: Higher UA levels are associated with lower risks of all-cause, cardiovascular and infection-associated mortality in women treated with continuous ambulatory peritoneal dialysis.

The association between time-mean serum uric acid levels and the incidence of chronic kidney disease in the general population: a retrospective study

Background

Investigations on the role of the time-mean serum uric acid (SUA) value in determining the risk of chronic kidney disease (CKD) are limited. We investigated whether the time-mean SUA value indicates the risk of CKD, and explored associations of the baseline and time-mean SUA levels with kidney function decline and incident CKD in a healthy population.

Methods

We initiated an inhabitant-based cohort study between January 2011 and December 2016. All participants completed a yearly medical check-up at the Zhejiang Province People’s Hospital and had baseline estimated glomerular filtration rates (eGFR) > 60 ml/min/1.73m². The SUA level and eGFR were assessed every year in the follow-up period. A multivariate adjusted binary logistic regression analysis and Cox proportional hazards models were used to evaluate the risk of newly-developed CKD among different stratified groups.

Results

During the 6-year follow-up period, 227 (4.4%) participants developed CKD. In multivariable-adjusted analyses, the odds ratio (OR) for new-onset CKD increased, with higher time-mean SUA levels than at baseline (OR: 1.00 [reference], 2.709 [95% confidence interval: 1.836–5.293], 3.754 [1.898–7.428], and 7.462 [3.694–15.073]). After adjustment for potential cofounders, a multivariate Cox proportional hazard model showed that a higher SUA increased the risk of developing CKD (the adjusted hazard ratios of the highest and lowest quartiles for the baseline and time-mean SUA levels were 1.689 [1.058–2.696] and 6.320 [3.285–12.159], respectively).

Conclusion

An increased time-mean and single SUA value were independently associated with an increased likelihood of eGFR decline and development of new-onset CKD in the general population.

A meta-analysis of the efficacy of allopurinol in reducing the incidence of myocardial infarction following coronary artery bypass grafting

Background

The xanthine oxidase inhibitor allopurinol that is commonly used to treat gout, has been suggested to have pleiotropic effects that are likely to reduce the incidence of myocardial infarction (MI) in at risk individuals. The aim of this meta-analysis was to assess the efficacy of allopurinol treatment in reducing the incidence of MI.

Method

MEDLINE, Scopus, Web of Science, and Cochrane Library databases were searched for randomised controlled trials examining the efficacy of allopurinol in reducing the incidence of MI. The quality of study methodology was assessed by two independent reviewers using the Cochrane Collaboration’s tool for assessing risk of bias. This meta-analysis was conducted using a fixed-effects model, and heterogeneity was assessed with the I² index.

Results

One thousand one hundred twenty-three citations were screened and only six studies satisfied the inclusion criterion. Published between 1988 and 1995, all studies examined the cardioprotective efficacy of allopurinol in the setting of coronary artery bypass graft (CABG). From a total pooled sample size of 229, MI was reported in 2 (1.77%) allopurinol and 14 (12.07%) control patients. A fixed-effects meta-analysis (I² = 0%) identified a statistically significant reduced incidence of myocardial infarction (RR 0.21, 95% CI: 0.06, 0.70, p = 0.01) in patients allocated to allopurinol. However, in the leave-one-out sensitivity analyses, the treatment effect became non-significant with the removal of one of the studies.

Conclusion

Based on the limited evidence available, allopurinol appears to reduce the incidence of perioperative MI following CABG. Further research is required to confirm these findings.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0881-6) contains supplementary material, which is available to authorized users.

Elevated serum uric acid predicts the development of moderate coronary artery calcification independent of conventional cardiovascular risk factors

BACKGROUND AND AIMS

Hyperuricemia was frequently noted in subjects with a high risk of cardiovascular disease (CVD). This study aimed to elucidate whether serum uric acid (SUA) is associated with development of moderate coronary artery calcification in generally healthy adults.

METHODS

A total of 9297 subjects underwent multidetector CT for the evaluation of CAC at least two times during their annual health examinations. Among them, 4461 participants without CVD history and who had no (scores 0) or minimal CAC (scores 1-10) in their first examination were enrolled. The association between SUA as a continuous and categorical variable and development of moderate coronary artery calcification (CAC score > 100) was assessed by Cox regression analysis. Receiver-operating characteristic (ROC) curves were constructed to investigate the diagnostic efficacy of SUA.

RESULTS

During a median follow-up of 4.1 years, 131 incident cases of moderate calcification developed. Baseline SUA concentration was significantly higher in subjects with progression to moderate coronary artery calcification (6.6 ± 1.3 vs. 5.8 ± 1.3 mg/dL, p < 0.001). SUA as a continuous variable (per 1 mg/dL) and divided into quartiles was positively associated with a higher risk of development of moderate calcification after adjustment for conventional CVD risk factors. The addition of SUA to the conventional CVD risk factors improved the predictive power for development of moderate coronary artery calcification.

CONCLUSIONS

SUA was an independent predictor for development of moderate coronary artery calcification in subjects with no or minimal calcification.

Measurement and Clinical Significance of Biomarkers of Oxidative Stress in Humans

Oxidative stress is the result of the imbalance between reactive oxygen species (ROS) formation and enzymatic and nonenzymatic antioxidants. Biomarkers of oxidative stress are relevant in the evaluation of the disease status and of the health-enhancing effects of antioxidants. We aim to discuss the major methodological bias of methods used for the evaluation of oxidative stress in humans. There is a lack of consensus concerning the validation, standardization, and reproducibility of methods for the measurement of the following: (1) ROS in leukocytes and platelets by flow cytometry, (2) markers based on ROS-induced modifications of lipids, DNA, and proteins, (3) enzymatic players of redox status, and (4) total antioxidant capacity of human body fluids. It has been suggested that the bias of each method could be overcome by using indexes of oxidative stress that include more than one marker. However, the choice of the markers considered in the global index should be dictated by the aim of the study and its design, as well as by the clinical relevance in the selected subjects. In conclusion, the clinical significance of biomarkers of oxidative stress in humans must come from a critical analysis of the markers that should give an overall index of redox status in particular conditions.

Association of diabetes mellitus with decline in ankle-brachial index among patients on hemodialysis: A 6-year follow-up study

Peripheral artery occlusive disease is common among diabetes mellitus (DM) and end-stage renal disease patients, and tends to progress faster and lead to worse outcomes. This study compared the association of DM with the decline in ankle-brachial index (ABI) among patients on hemodialysis (HD). This was a longitudinal analysis of ABI in HD patients from 2009 to 2015. Medical records and yearly ABI values were obtained. A longitudinal mixed-model analysis was used to evaluate ABI changing trends while accounting for within-patients correlation. There were 296 patients on HD in the period of 2009-2015. In a 6-year follow-up, those with DM had a more rapid ABI decline compared to non-DM patients (slopes: -0.014 vs. 0.010 per year, interaction p < 0.001). In DM patients, female sex, high pulse pressure, high triglyceride, low creatinine, and high uric acid were associated with a decrease in ABI. In non-DM patients, old age, high pulse pressure, high low-density lipoprotein cholesterol, and high uric acid were associated with a decreased in ABI. There were 49.6% of patients with a normal ABI experienced a decrease at least 0.1 of ABI from baseline, and 35.3% had a final ABI < 0.9 in patients with a baseline ABI ≥ 0.9 (n = 232). In this study, DM patients on HD tend to develop a more rapid decline in ABI than non-DM patients on HD. Age, sex, pulse pressure, lipid profile, creatinine, and uric acid are associated with a decreased in ABI.

Serum Uric Acid Is Associated with Poor Outcome in Black Africans in the Acute Phase of Stroke

BACKGROUND

Prognostic significance of serum uric acid (SUA) in acute stroke still remains controversial.

OBJECTIVES

To determine the prevalence of hyperuricemia and its association with outcome of stroke patients in the Douala General Hospital (DGH).

METHODS

This was a hospital based prospective cohort study which included acute stroke patients with baseline SUA levels and 3-month poststroke follow-up data. Associations between high SUA levels and stroke outcomes were analyzed using multiple logistic regression and survival analysis (Cox regression and Kaplan-Meier).

RESULTS

A total of 701 acute stroke patients were included and the prevalence of hyperuricemia was 46.6% with a mean SUA level of 68.625 ± 24 mg/l. Elevated SUA after stroke was associated with death (OR = 2.067; 95% CI: 1.449-2.950; p < 0.001) but did not predict this issue. However, an independent association between increasing SUA concentration and mortality was noted in a Cox proportional hazards regression model (adjusted HR = 1.740; 95% CI: 1.305-2.320; p < 0.001). Furthermore, hyperuricemia was an independent predictor of poor functional outcome within 3 months after stroke (OR = 2.482; 95% CI: 1.399-4.404; p = 0.002).

CONCLUSION

The prevalence of hyperuricemia in black African stroke patients is quite high and still remains a predictor of poor outcome.

Association of serum uric acid and cardioembolic stroke in patients with acute ischemic stroke

BACKGROUND

Although high uric acid levels have been reported to be a risk factor for cardiovascular disease and stroke, the relationship between serum uric acid (SUA) levels and cardioembolic stroke (CES) has not been fully elucidated. In this study, we sought to investigate the relationship between the risk of CES and SUA levels. We hypothesized that SUA concentrations are associated with CES.

METHODS

We retrospectively analyzed 2350 patients with acute ischemic stroke who were admitted to the Seoul National University Hospital between 2002 and 2010. The participants were stratified into five groups according to SUA levels obtained within 24h after stroke onset. The association between SUA levels and CES was evaluated using multivariable logistic regression models.

RESULTS

Of the 2350 patients, 412 (27.7%) were classified with CES, and 1077 (72.3%) were classified with non-CES, including LAA (large artery atherosclerosis) and SVO (small vessel occlusion). Among the acute stroke patients, SUA levels were higher in those with atrial fibrillation and other cardiovascular risk factors. Compared with the non-CES patients, the CES patients were more likely to fall in the highest quintile of SUA level. Multivariate analysis revealed that the patients with SUA concentrations in the highest quintile were associated with CES (OR=2.59, 95% CI: 1.35-4.97), test for trend P<0.001. Similar results were obtained for gender-based subgroups by (in men, OR=2.34, 95% CI: 1.06-5.15 and in women OR=3.41, 95% CI: 1.15-10.07), test for trend P<0.01 and P<0.001, respectively.

CONCLUSION

SUA level is associated with the risk of CES in acute ischemic stroke patients of both sexes. Further prospective clinical trials of lowering SUA to prevent CES may be worth considering.

Starting with Rosuvastatin in Primary Hyperlipidemia—

The authors investigated the effects of rosuvastatin, beyond its lipid-lowering activity, on several nonlipid metabolic variables, along with its safety and tolerability, in patients treated for primary hyperlipidemia. Patients (n=55) with primary hyperlipidemia were open-label assigned to the recommended starting dose of rosuvastatin 10 mg/day, and serum metabolic variables were measured at baseline and after 8 and 20 weeks. Treatment with rosuvastatin produced significant reductions in total cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein B, nonhigh-density lipoprotein cholesterol (non HDL-C), and triglyceride concentrations, whereas HDL-C, apolipoprotein A-I, and lipoprotein(a) levels did not change significantly from baseline. The LDL-C treatment target was achieved in 71% of patients. No significant variations in renal function parameters (serum creatinine and creatinine clearance), insulin resistance estimates, and serum concentrations of uric acid, total homocysteine, vitamin B12, and folic acid were observed during the period of treatment. High-sensitivity C-reactive protein levels were significantly lowered by rosuvastatin therapy (median values, 3.1 vs 2.0 vs 1.9 mg/L, at 0, 8, and 20 weeks, respectively; p<0.0001). In conclusion, rosuvastatin at 10 mg/day is a highly effective, safe, and well-tolerated monotherapy option for patients with primary hyperlipidemia, with a favorable antiinflammatory potential and nondeteriorating effects on renal function.

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.

Uric Acid and Cardiovascular Disease: An Update

In recent years, serum uric acid (SUA) as a determinant of cardiovascular (CV) risk has gained interest. Epidemiological, experimental and clinical data show that patients with hyperuricaemia SUA are at increased risk of cardiac, renal and vascular damage and CV events. There is now some evidence to suggest that urate-lowering treatment may reduce CV risk in this group and, thus, may represent a new strategy in risk reduction.

Association of Far-Infrared Radiation Therapy and Ankle-Brachial Index of Patients on Hemodialysis with Peripheral Artery Occlusive Disease

Background and Aim: The ankle-brachial index (ABI) is recognized to be a good marker for atherosclerosis, and is useful in the diagnosis of peripheral artery occlusive disease (PAOD) which is prevalent among patients on hemodialysis (HD). Methods: This randomized trial aimed to evaluate the effect of far-infrared radiation (FIR) therapy on ABI in HD patients with PAOD. PAOD was defined as patients with ABI < 0.95. One hundred and eight HD patients were enrolled, including 50 in the control group and 58 in the FIR group. A WS TY101 FIR emitter was applied for 40 minutes during each HD session, three times per week for six months. The ABI was measured before and after the FIR therapy. Results: Regardless of FIR therapy, the bilateral ABI decreased (in the FIR group, left: 0.88±0.22 to 0.85±0.24, p = 0.188; right: 0.92±0.20 to 0.90±0.23, p = 0.372; in control group, left: 0.91±0.23 to 0.88±0.21, p = 0144; right: 0.93±0.17 to 0.89±0.21, p = 0.082). Multivariate logistic analysis of the FIR group revealed that high uric acid (odds ratio [OR]: 2.335; 95% confidence interval [CI]: 1.117-4.882; p=0.024) and aspirin use (OR: 16.463; 95% CI: 1.787-151.638; p=0.013) were independently associated with increased bilateral ABI after FIR therapy. Conclusions: This study demonstrates that ABI is not increased after FIR therapy in HD patients with PAOD. However, in the FIR group, patients with higher uric acid level or those who used aspirin have increased bilateral ABI after FIR therapy.

Hyperuricemia in systemic lupus erythematosus: is it associated with the neuropsychiatric manifestations of the disease?

OBJECTIVES

To assess the association between hyperuricemia and different neuropsychiatric manifestations and stroke risk factors in systematic lupus erythematosus (SLE) patients.

METHODS

This study was conducted on 204 SLE patients who were admitted to a tertiary referral center. A standardized questionnaire was completed for all the participants and the medical records were reviewed regarding the occurrence of arterial or venous thrombotic events, stroke, seizure, depression, headache, psychosis, and peripheral neuropathy. In addition blood samples were drawn to obtain serum uric acid, triglyceride (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and total cholesterol levels.

RESULTS

Hyperuricemia (serum uric acid ≥6mg/dl for women and ≥7mg/dl for men) was detected in 16.1% of SLE patients and was significantly associated with the occurrence of stroke (OR, 2.38; 95%CI, 1.2-7.24), and peripheral neuropathy (OR, 3.49; 95% CI, 1.52-12.23), independent of hypertension and hyperlipidemia. Hyperuricemia was also significantly associated with hypertension (OR, 7.76; 95% CI, 2.72-15.76), hyperlipidemia (OR, 5.05; 95% CI, 1.59-11.32), and history of arterial thrombosis (OR, 4.95; 95% CI, 1.98-15.34), independent of age and body mass index.

CONCLUSIONS

Hyperuricemia in SLE patients is independently associated with the occurrence of stroke and peripheral neuropathy. It is also independently associated with hypertension, hyperlipidemia, and history of arterial thrombosis, which are the major stroke and myocardial infarction risk factors in SLE patients.

[Hyperuricemia in systemic lupus erythematosus: is it associated with the neuropsychiatric manifestations of the disease?]

OBJECTIVES

To assess the association between hyperuricemia and different neuropsychiatric manifestations and stroke risk factors in systematic lupus erythematosus (SLE) patients.

METHODS

This study was conducted on 204 SLE patients who were admitted to a tertiary referral center. A standardized questionnaire was completed for all the participants and the medical records were reviewed regarding the occurrence of arterial or venous thrombotic events, stroke, seizure, depression, headache, psychosis, and peripheral neuropathy. In addition blood samples were drawn to obtain serum uric acid, triglyceride (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and total cholesterol levels.

RESULTS

Hyperuricemia (serum uric acid ≥ 6mg/dl for women and ≥ 7mg/dl for men) was detected in 16.1% of SLE patients and was significantly associated with the occurrence of stroke (OR, 2.38; 95%CI, 1.2-7.24), and peripheral neuropathy (OR, 3.49; 95% CI, 1.52-12.23), independent of hypertension and hyperlipidemia. Hyperuricemia was also significantly associated with hypertension (OR, 7.76; 95% CI, 2.72-15.76), hyperlipidemia (OR, 5.05; 95% CI, 1.59-11.32), and history of arterial thrombosis (OR, 4.95; 95% CI, 1.98-15.34), independent of age and body mass index.

CONCLUSIONS

Hyperuricemia in SLE patients is independently associated with the occurrence of stroke and peripheral neuropathy. It is also independently associated with hypertension, hyperlipidemia, and history of arterial thrombosis, which are the major stroke and myocardial infarction risk factors in SLE patients.

The Association between Serum Uric Acid Levels and the Prevalence of Vulnerable Atherosclerotic Carotid Plaque: A Cross-sectional Study

Little is known about the associations between serum uric acid (SUA) levels and atherosclerotic carotid plaque vulnerability. The aim of this study was to assess the associations of SUA levels with the prevalence of vulnerable atherosclerotic carotid plaque in a community-based cohort. In the Asymptomatic Polyvascular Abnormalities Community (APAC) study, cross-sectional data from 2860 Chinese residents who underwent SUA measurement and ultrasonographic assessment of carotid plaque were analyzed. Multivariable logistic regression models were used to assess the associations of SUA levels with presence of vulnerable carotid plaque. After adjustment for potential confounders, SUA levels were significantly associated with the prevalence of vulnerable plaque amongst the middle-aged adults (odds ratio [OR] = 1.19, 95% confidence interval [CI]: 1.11-1.28). Compared to the lowest quartile, quartiles 2, 3 and 4 had a prevalence OR of 1.33 (1.02-1.74), 1.70 (1.27-2.27) and 2.05 (1.53-2.75), respectively, for the presence of vulnerable carotid plaque (p for trend across quartiles < 0.001). In the APAC study, elevated SUA levels were independently associated with the prevalence of vulnerable carotid plaque in middle-aged adults.

Prognostic value of serum uric acid: new-onset in and out-of-office hypertension and long-term mortality

OBJECTIVE

Serum uric acid (SUA) has been associated with an increased cardiovascular risk, but no conclusive evidence exists on whether it is an independent risk factor or a reflection of other risk factors to which it is related. We examined the relationship of SUA with a number of cardiovascular variables [including risk factors never evaluated before, such as organ damage and out-of-office blood pressure (BP)], as well as its prognostic relevance in the population.

METHODS

In 2045 participants of the Pressioni Arteriose Monitorate E Loro Associazioni study, we measured, along with SUA, metabolic, renal, and anthropometric variables, left-ventricular mass index, and office, home and ambulatory BP. Cardiovascular and all-cause mortality was assessed over a 16-year follow-up period, and measurements were repeated 10 years after the initial data collection.

RESULTS

Baseline SUA had a near-normal distribution, with a mean value of 4.9 ± 1.3 (SD) mg/dl and a significant direct relationship with BP and metabolic variables, serum creatinine and left-ventricular mass index. It was among the factors independently predicting new-onset home and ambulatory hypertension, the increased risk of developing these conditions for 1  mg/dl increase of SUA after adjustment for all available potential confounders being 34 and 29%, respectively (P = 0.015 and P = 0.014). An increase in SUA of 1  mg/dl also independently predicted cardiovascular and all-cause mortality, the fully adjusted increase in risk being 22% (P = 0.03) and 12% (P = 0.04), respectively.

CONCLUSION

In the general population of the Pressioni Arteriose Monitorate E Loro Associazioni study, SUA correlated with a number of cardiovascular risk factors. Nevertheless, it independently predicts new-onset out-of-office hypertension, and long-term cardiovascular and all-cause mortality.

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.

Uric acid is associated with metabolic syndrome in children and adults in a community: the Bogalusa Heart Study

BACKGROUND

Elevated serum uric acid (UA) is commonly found in subjects with metabolic syndrome (MetS). This study examined the association of UA with levels of individual MetS components and the degree of their clustering patterns in both children and adults.

METHODS

The study sample consisted of 2614 children aged 4-18 years and 2447 adults aged 19-54 years. MetS components included body mass index (BMI), mean arterial pressure (MAP), triglycerides to high-density lipoprotein cholesterol ratio (TG/HDLC), and homeostasis model assessment of insulin resistance (HOMA). Observed/expected (O/E) ratio and intra-class correlation coefficient (ICC) were used as a measure of the degree of clustering of categorical and continuous MetS variables, respectively.

RESULTS

UA was positively and significantly associated only with BMI in children but with all four components in adults. The odds ratio for MetS associated with 1 mg/dL increase of UA was 1.74 (p<0.001) in children and 1.92 (p<0.001) in adults. O/E ratios showed a significant, increasing trend with increasing UA quartiles in both children and adults for 3- and 4-variable clusters with p-values for trend <0.001, except for BMI-MAP-TG/HDLC and MAP-TG/HDLC-HOMA clusters in children and MAP-TG/HDLC-HOMA cluster in adults. ICCs of 3 and 4 components increased with increasing UA quartiles in children and adults.

CONCLUSIONS

These results indicate that UA may play a role in the development of MetS in both pediatric and adult populations alike, which may aid in the identification and treatment of high risk individuals for MetS and related clinical disorders in early life.

Increased ventricular pacing threshold levels in patients with high serum uric acid levels

BACKGROUND

Permanent cardiac pacemakers (PCM) are accepted as the most effective treatment for symptomatic bradyarrhythmias. Serum uric acid (UA) levels are associated with various inflammatory markers, oxidative stress, and endothelial dysfunction. This study aimed to investigate the association between serum UA and ventricular pacing threshold (VPT) levels in patients who underwent permanent pacemaker implantation.

MATERIALS AND METHODS

We retrospectively analyzed a total of 198 patients who underwent PCM implantation for indications such as symptomatic bradycardia without a reversible etiology and high-degree and complete atrioventricular block.

RESULTS

VPT values were found to correlate with serum UA levels (r=0.591, p<0.001), high sensitivity C-reactive protein (hs-CRP) levels (r=0.505, p<0.001), and ventricular impedance (r=0.220, p=0.016). The serum UA levels and hs-CRP levels were also correlated (r=0.691, p<0.001). To identify independent risk factors for VPT values, a multivariate linear regression model was conducted, and serum UA levels (β=0.361, p=0.001), hs-CRP levels (β=0.277, p=0.012), and impedance values (β=0.207, p=0.011) were found to be independent risk factors for VPT.

CONCLUSION

In the present study, VPT values at the time of implantation and at the 30th day were increased in patients with high serum UA levels. To further extend the life of pacemakers, as well as other factors that affect threshold values, serum UA levels should be noted.

Serum uric acid and cardiovascular risk: state of the art and perspectives

Hyperuricaemia is commonly found in subjects with cardiovascular disease, but its role as risk factor is very controversial. Although several studies reported serum uric acid as a marker of an underlying pathophysiological process, other studies hypothesis a potential causal link between serum uric acid and cardiovascular diseases. Some studies suggest that uric acid is biologically active and may have an atherogenesis role in development of cardiovascular diseases, although the mechanisms are not fully understood. Other studies have shown that uric acid can independently predict the development of some cardiovascular risk factors such as hypertension and metabolic syndrome, as well as myocardial infarction and stroke. The relations between serum uric acid and established cardiovascular risk factors are complex, and these latter could be considered as confounding factors. In this report, we review the inextricably link of serum uric acid to known cardiovascular risk factors, and we describe the possible mechanisms and potential causative role between serum uric acid and cardiovascular events in the general population, in subjects with cardiovascular risk factors and in those with pre-existing cardiovascular diseases. Limited information however is available concerning the impact of urate-lowering treatments on cardiovascular events, whereas only a positive therapeutic trial could give definite answers to the difficult problem of causality of uric acid in relation to cardiovascular risk. Thus, it is time to propose the design of a therapeutic trial, integrating cardiologists and rheumatologists, in order to further decrease cardiovascular risk.

Potential role of uric acid in metabolic syndrome, hypertension, kidney injury, and cardiovascular diseases: is it time for reappraisal?

Elevated serum uric acid concentration is a common laboratory finding in subjects with metabolic syndrome/obesity, hypertension, kidney disease and cardiovascular events. Hyperuricemia has been attributed to hyperinsulinemia in metabolic syndrome and to decreased uric acid excretion in kidney dysfunction, and is not acknowledged as a main mediator of metabolic syndrome, renal disease, and cardiovascular disorder development. However, more recent investigations have altered this traditional view and shown, by providing compelling evidence, to support an independent link between hyperuricemia and increased risk of metabolic syndrome, diabetes, hypertension, kidney disease and cardiovascular disorders. However, despite these new findings, controversy regarding the exact role of uric acid in inducing these diseases remains to be unfolded. Furthermore, recent data suggest that the high-fructose diet in the United State, as a major cause of hyperuricemia, may be contributing to the metabolic syndrome/obesity epidemic, diabetes, hypertension, kidney disease and cardiovascular disorder. Our focus in this review is to discuss the available evidence supporting a role for uric acid in the development of metabolic syndrome, hypertension, renal disease, and cardiovascular disorder; and the potential pathophysiology mechanisms involved.

Effects of uric acid levels on outcome in severe ischemic stroke patients treated with intravenous recombinant tissue plasminogen activator

Uric acid (UA) has been known to be a neuroprotective antioxidant because of its free radical scavenger activity. We studied the influence of UA in patients with acute ischemic stroke after thrombolytic therapy. Two hundred eighteen consecutive patients treated with intravenous thrombolysis were included in this analysis. We analyzed the relationship between serum UA levels obtained at the emergency department and clinical outcomes. Early improvement and excellent functional outcomes were measured using the National Institutes of Health Stroke Scale (NIHSS) 24 h after onset and the modified Rankin scale after 3 months. There was no significant relationship between serum UA levels and early improvement or excellent functional outcome in the total patients (p = 0.583 and p = 0.082, respectively). However, in patients with severe baseline stroke deficits (NIHSS score ≥15), higher-tertile UA levels were significantly associated with excellent functional outcomes (p = 0.003). Excellent functional outcomes in patients with severe baseline disability might have a significant association with serum UA levels particularly in men but not in women (p = 0.007 in men and p = 0.621 in women). Increased serum UA levels might be associated with better outcomes in ischemic stroke patients treated with intravenous thrombolysis, but the effectiveness of UA can differ by initial stroke severity and gender.

Serum urate and incidence of kidney disease among veterans with gout

OBJECTIVE

To study the association between serum urate level (sUA) and the risk of incident kidney disease among US veterans with gouty arthritis.

METHODS

From 2002 through 2011 adult male patients with gout who were free of kidney disease were identified in the data from the Veterans Administration VISN 16 database and were followed until incidence of kidney disease, death, or the last available observation. Accumulated hazard curves for time to kidney disease were estimated for patients with average sUA levels > 7 mg/dl (high) versus ≤ 7 mg/dl (low) based on Kaplan-Meier analyses; and statistical comparison was conducted using a log-rank test. A Cox proportional hazard model with time-varying covariates was used to estimate the unadjusted and adjusted hazard ratios for kidney disease.

RESULTS

Eligible patients (n = 2116) were mostly white (53%), with average age 62.6 years, mean body mass index 31.2 kg/m(2), and high baseline prevalence of hypertension (93%), hyperlipidemia (67%), and diabetes (20%). Mean followup time was 6.5 years. The estimated rates of all incident kidney disease in the overall low versus high sUA groups were 2% versus 4% at Year 1, 3% versus 6% at Year 2, and 5% versus 9% at Year 3, respectively (p < 0.0001). After adjustment, high sUA continued to predict a significantly higher risk of kidney disease development (HR 1.43, 95% CI 1.20-1.70).

CONCLUSION

Male veterans with gout and sUA levels > 7 mg/dl had an increased incidence of kidney disease.

Hyperuricemia is an independent risk factor for mortality only if chronic kidney disease is present

BACKGROUND/AIMS

Hyperuricemia has been considered a risk factor for renal disease and cardiovascular disease. However, the potential contribution of hyperuricemia to mortality remains uncertain, and the results in the available literature vary according to kidney function. The aim of this study was to determine the association between hyperuricemia and mortality in patients undergoing percutaneous coronary intervention (PCI) across the interaction of kidney function.

METHOD

We retrospectively reviewed patients who underwent PCI from 2003 to 2009. Propensity scores for hyperuricemia (>7 mg/dl for males and >6 mg/dl for females) were used to assemble a matched cohort of 693 pairs of patients with and without hyperuricemia for analysis from the 3,201 patients who fulfilled the inclusion criteria among the 4,842 patients who underwent PCI.

RESULTS

Of the 3,201 patients who underwent PCI and for whom data were available regarding their baseline serum uric acid level, 763 (23.8%) had hyperuricemia. The hyperuricemia-associated hazard ratios (HRs) [95% confidence intervals (CIs)] for all-cause mortality were 1.780 (1.270-2.495) in the unmatched cohort and 1.655 (1.109-2.468) in the matched cohort. The HRs (95% CI) for all-cause mortality among those with and without chronic kidney disease (CKD) were 2.080 (1.318-3.283) and 1.592 (0.778-3.256), respectively (p for interaction, 0.001).

CONCLUSIONS

Hyperuricemia is an independent risk factor for all-cause mortality in those patients with CKD but not in those without CKD.

Lack of association between serum uric acid levels and outcome in acute ischemic stroke

BACKGROUND

The prognostic value of serum uric acid (UA) in acute ischemic stroke is controversial. The aim of this study is to further analyse the relation between UA and outcome after acute ischemic stroke.

METHODS

We analysed UA levels in blood samples collected within 6h of stroke onset from patients included in the placebo arm of the US and Canadian Lubeluzole Ischemic Stroke Study (LUB-INT-9). We compared mean serum UA levels in patients with and without early neurological improvement (≥ 4 versus <4 points improvement on NIHSS after 5 days) and in patients with good functional and poor functional outcome (mRS 0-2 versus mRS 3-6). Multivariable logistic regression analyses were performed to adjust for possible confounders.

RESULTS

UA levels of 226 patients were available for analysis. Mean serum UA levels were not significantly higher in patients with than without early neurological improvement (0.33 mmol/L versus 0.30 mmol/L, p=0.070). The difference between patients with good and patients with poor functional outcome was borderline statistically significant (0.34 mmol/L versus 0.31 mmol/L, p=0.050). After adjustment for confounders, higher serum UA levels were neither associated with early neurological improvement OR (1.30, 95% CI 0.98-1.73, p=0.069), nor with a good functional outcome (OR 1.09, 95% CI 0.72-1.65, p=0.690).

CONCLUSION

We found no association between admission serum UA levels and both short- and long-term outcome in acute ischemic stroke.

New insights into uric acid effects on the progression and prognosis of chronic kidney disease

Hyperuricemia is particularly common in patients with arterial hypertension, metabolic syndrome, or kidney disease. Its role, however, as a risk factor for both renal and cardiovascular outcomes and in the context of the well-established interrelationship between cardiovascular disease and chronic kidney disease (CKD) is debated. For decades high serum uric acid levels were mainly considered the result of renal dysfunction and not a true mediator of renal disease development and progression. However, recent epidemiological studies suggest an independent association between asymptomatic hyperuricemia and increased risk of arterial hypertension, CKD, cardiovascular events, and mortality. Furthermore, data from experimental models of hyperuricemia have provided robust evidence in this direction. Hyperuricemia causes increased arterial pressure, proteinuria, renal dysfunction, and progressive renal and vascular disease in rats. The main pathophysiological mechanisms of these deleterious effects caused by uric acid are endothelial dysfunction, activation of local renin-angiotensin system, increased oxidative stress, and proinflammatory and proliferative actions. A small number of short-term, single-center clinical studies support the beneficial influence of pharmaceutical reduction of serum uric acid on total cardiovascular risk, as well as on renal disease development and progression. Hyperuricemia is probably related to the incidence of primary hypertension in children and adolescents, as serum uric acid lowering by allopurinol has an antihypertensive action in this group of patients. Finally, it is clear that adequately powered randomized controlled trials are urgently required to elucidate the role of uric acid in cardiovascular events and outcomes, as well as in the development and progression of CKD.