Serum uric acid concentrations and risk of intracerebral hemorrhage: A systematic review and meta-analysis

J-shaped relationship between Chinese visceral adiposity index and hyperuricemia: a cross-sectional study

BACKGROUND

Recent years have seen the emergence of numerous novel indicators for visceral obesity. This study investigates the potential correlation between the Chinese visceral adiposity index (CVAI) and hyperuricemia (HUA).

METHODS

This research, derived from a 2011 cross-sectional analysis in Dalian, China, employed restricted cubic spline (RCS) plots to identify inflection points. Subsequently, one-way and multifactorial logistic regression models were utilized, with HUA as the outcome variable. Additionally, subgroup analyses and interaction tests were conducted. Eventually, receiver operating characteristic (ROC) curves were calculated to assess the effectiveness of CVAI and other body composition indices in predicting HUA.

RESULTS

The study included 10,061 individuals, with a HUA prevalence of 14.25%. Significant relationships with HUA were observed for CVAI. RCS analysis revealed a J-shaped relationship between CVAI and HUA. Compared to those in the low CVAI category, HUA was notably associated with individuals in the high CVAI category in multifactorial logistic regression (OR = 2.661, 95% CI: 2.323, 3.047). Subgroup analyses demonstrated stronger relationships in women, participants without hypertension, and participants without diabetes. Additional modeling via ROC curves suggested that the CVAI may offer effective predictive value for HUA.

CONCLUSION

This study confirmed that an elevated CVAI elevates the risk of HUA in middle-aged and elderly populations in the Dalian community. The findings advance obesity prevention strategies that mitigate HUA risk and support healthcare initiatives for China's aging population.

Association of serum uric acid level with intracranial aneurysms: A Mendelian randomization study

Objective

Numerous studies have posited the involvement of serum uric acid (SUA) in the pathogenesis and progression of various cardiovascular diseases, particularly aortic aneurysms. However, the casual effect of SUA level on intracranial aneurysms (IAs) was rarely studied. Consequently, we aimed to explore the causal association between SUA and IAs using Mendelian randomization (MR) analysis.

Methods

We conducted a two-sample MR analysis with SUA as the exposure variable and IAs as the outcome variable. Genome-wide association study (GWAS) datasets for SUA were acquired from the Open GWAS catalog, including 389,404 European and 129,405 East Asian individuals. The dataset for IAs was sourced from a meta-analysis of GWASs comprising 317,636 individuals across different ancestral populations (European: 7495 cases and 71,934 controls; East Asian: 3259 cases and 234,948 controls). The MR analyses were performed according to populations (European and East Asian) and IAs status [unruptured IAs (uIAs) or aneurysmal subarachnoid hemorrhage (aSAH)], respectively. The inverse variance weighted (IVW) method was employed as primary analysis to discern causal estimates.

Results

Our findings revealed that an elevated genetically predicted SUA level (mg/dL) correlated with an increased risk of IAs among the European population (OR = 1.29 [95%CI:1.05-1.57], P = 0.013) and East Asian population (OR = 1.56 [95%CI: 1.27-1.92], P < 0.001). Among European individuals, subgroup analysis indicated a persistent causal association of SUA with uIAs (OR = 1.50 [95%CI: 1.08-2.08], P = 0.015) and aSAH (OR = 1.26 [95%CI: 1.00-1.60], P = 0.049). However, subgroup analysis in East Asian populations was not conducted due to the lack of separate data on uIAs and aSAH.

Conclusions

Our MR analysis demonstrated a causal relationship between elevated SUA levels and an amplified risk of IAs. Further rigorous investigations are imperative to provide evidence and elucidate the underlying mechanisms.

Prognostic Significance of Uric Acid Levels in Intracerebral Hemorrhage Patients

Background and Purpose

The role of serum uric acid (UA) level in patients suffering from stroke remains controversial. Our aim was to investigate the effect of UA level on clinical outcomes in patients with intracerebral hemorrhage (ICH).

Methods

In the retrospective cohort study, we analyzed data from 250 patients with intracerebral hemorrhage (85 women and 165 men) to investigate the difference in UA levels between patients with a good prognosis and those with a poor prognosis. Additionally, we analyzed the impact of UA levels on the risk of short-time prognosis of ICH patients.

Results

Patients with a good prognosis presented with significantly lower levels of UA (348.71 ± 84.97 μmol/L) than those with poor prognosis (393.06 ± 148.46 μmol/L). Furthermore, multivariate logistic regression model demonstrated that a high UA level was a likely risk factor for worse prognosis among patients suffering in ICH (odds ratio [95% confidence interval], 1.006 [1.0012, 1.0108]; P = 0.015). Additionally, UA has a threshold effect value of 363.9 μmol/L and was presented in levels that were in a nonlinear relationship with incidence rate of short-time prognosis outcome of ICH patients.

Conclusion

Our findings indicate that higher UA levels can increase the risk of poor clinical prognosis in patients with ICH and high UA levels are not conductive to the clinical prognosis of patients with ICH. These findings provide a new perspective on the treatment and prevention of ICH.

Dysuricemia

Gout results from elevated serum urate (SU) levels, or hyperuricemia, and is a globally widespread and increasingly burdensome disease. Recent studies have illuminated the pathophysiology of gout/hyperuricemia and its epidemiology, diagnosis, treatment, and complications. The genetic involvement of urate transporters and enzymes is also proven. URAT1, a molecular therapeutic target for gout/hyperuricemia, was initially derived from research into hereditary renal hypouricemia (RHUC). RHUC is often accompanied by complications such as exercise-induced acute kidney injury, which indicates the key physiological role of uric acid. Several studies have also revealed its physiological role as both an anti-oxidant and a pro-oxidant, acting as both a scavenger and a generator of reactive oxygen species (ROSs). These discoveries have prompted research interest in SU and xanthine oxidoreductase (XOR), an enzyme that produces both urate and ROSs, as status or progression biomarkers of chronic kidney disease and cardiovascular disease. The notion of "the lower, the better" is therefore incorrect; a better understanding of uric acid handling and metabolism/transport comes from an awareness that excessively high and low levels both cause problems. We summarize here the current body of evidence, demonstrate that uric acid is much more than a metabolic waste product, and finally propose the novel disease concept of "dysuricemia" on the path toward "normouricemia", or optimal SU level, to take advantage of the dual roles of uric acid. Our proposal should help to interpret the spectrum from hypouricemia to hyperuricemia/gout as a single disease category.

Effect of changes in serum uric acid on the risk of stroke and its subtypes

BACKGROUND AND AIMS

The role of serum uric acid (SUA) in stroke remains controversial and analyses of changes in SUA and stroke are limited. The objective of the study was to investigate the associations of changes in SUA with stroke and its subtypes (ischemic and hemorrhagic stroke).

METHODS AND RESULTS

A total of 51 441 participants (mean age 52.69 ± 11.71 years) without history of myocardial infarction or stroke were enrolled. Participants were divided into four groups based on SUA level changes during 2006 and 2010: stable low, increasing, decreasing, and stable high. SUA score was quantified on a 3-point scale with 1 point awarded for hyperuricemia at either year 2006, 2008 or 2010. Multivariate Cox proportion models were used to calculated hazard ratios (HRs) and their 95% confidence intervals (CIs). During 7.03-year follow up, 1611 stroke (1410 ischemic stroke, 199 hemorrhagic stroke, and 47 subarachnoid hemorrhage) were identified. Participants with stable high SUA had higher risk of hemorrhagic stroke, the HR was 1.93 (95% CI: 1.06-3.51), compared to those with stable low SUA. Furthermore, cumulative high SUA exposure also increased the risk of hemorrhagic stroke, the HR (95%CI) was 2.99 (1.55-5.74), compared with cumulative low SUA exposure. However, no significant evidence indicated changes in SUA was associated with the risk of total and ischemic stroke, the HRs (95% CIs) were 0.98 (0.74-1.29) and 0.88 (0.65-1.19), respectively.

CONCLUSIONS

Stable high SUA was positively associated with the risk of hemorrhagic stroke, but not with total and ischemic stroke risk.

Hyperuricemia, Gout, and the Brain-an Update

PURPOSE OF REVIEW

This review aims to summarize recent evidence regarding the complex relationship between uric acid (UA), gout, and brain diseases.

RECENT FINDINGS

Observational studies have suggested that patients with hyperuricemia or gout might have a decreased risk of neurodegenerative diseases. Conversely, they may be at increased risk of cerebrovascular disease. Mendelian randomization (MR) studies use a genetic score as an instrumental variable to address the causality of the association between a risk factor (here, UA or gout) and an outcome. So far, MR analyses do not support a causal relationship of UA or gout with Alzheimer's disease and dementia, and of UA with Parkinson's disease or stroke. Observation studies indicate a U-shaped association between UA and brain diseases, but MR studies do not support that this association is causal. Further studies should address the causal role of gout as well as the impact of urate-lowering therapy on these outcomes.

The Relationship Between Elevated Serum Uric Acid and Risk of Stroke in Adult: An Updated and Dose-Response Meta-Analysis

Background: Uric acid (UA) is proposed as a potential risk factor for stroke in adult, yet the results from published studies are not generally accordant.

Method: We included prospective studies that explored the relationship between serum UA (SUA) and strokes. In this study, strokes include ischemic stroke and hemorrhagic stroke, which consists of intracerebral hemorrhage and subarachnoid hemorrhage. The effect-size estimates were expressed as hazard ratio (HR) and 95% confidence interval (CI). Sensitivity and subgroup analyses were performed to assess the robustness of the pooled estimation and potential sources of heterogeneity between studies.

Results: We meta-analyzed 19 prospective cohort articles, which involve 37,386 males and 31,163 females. Overall analyses results showed a significant association between a 1 mg/dl increase in high levels of SUA and the risk of total stroke (HR = 1.13; 95% CI: 1.09–1.18; P < 0.001), ischemic stroke (HR = 1.15; 95% CI: 1.10–1.21; P < 0.001), and hemorrhagic stroke (HR = 1.07; 95% CI: 1.00 to 1.15; P = 0.046). No significant difference was found between ischemic stroke and hemorrhagic stroke. In the subgroup analyses, the association of high SUA levels and the risk of total stroke was statistically significant in females (HR = 1.19; 95% CI: 1.12–1.26; P < 0.001) and males (HR = 1.11; 95% CI: 1.05–1.17; P < 0.001). Coincidentally, the association was also statistically significant for ischemic stroke, both in females (HR = 1.26; 95% CI: 1.17–1.36; P < 0.001) and in males (HR = 1.12; 95% CI: 1.06–1.19; P < 0.001). However, for hemorrhagic stroke, it was only statistically significant in females (HR = 1.19; 95% CI: 1.04–1.35; P = 0.01). Our dose–response research indicated the J-shaped trend between the ascending SUA levels and the higher risk of suffering from a stroke.

Conclusions: Our findings indicate that elevated SUA is a significant risk factor for adult stroke, both for ischemic stroke and hemorrhagic stroke, and especially in females.

Relationship of Serum Uric Acid to Hematoma Volume and Prognosis in Patients with Acute Supratentorial Intracerebral Hemorrhage

BACKGROUND

Oxidative stress and inflammation play important roles in the neuronal injury caused by intracerebral hemorrhage (ICH). Uric acid (UA), an important natural antioxidant, might reduce the neuronal injury caused by ICH. Delineating the relationship between UA and ICH will enhance our understanding of antioxidative mechanisms in recovery from ICH.

METHODS

We conducted a retrospective study of 325 patients with acute supratentorial ICH to investigate the relationship between serum UA levels and hematoma volumes and prognosis. A hematoma volume of ≥30 mL was defined as a large hematoma. An unfavorable outcome was defined as a modified Rankin scale score of 4-6 on day 30.

RESULTS

The serum UA level was significantly lower in the patients with a large hematoma volume (median, 306 μmol/L; 25th to 75th percentile, 243-411 μmol/L) than in those with a small hematoma volume (median, 357 μmol/L; 25th to 75th percentile, 271-442 μmol/L; P = 0.012). Similarly, the unfavorable outcome group had had lower serum UA levels (median, 309 vs. 363 μmol/L; P = 0.009) compared with the favorable outcome group. The results of the multivariate logistic analysis indicated that a lower serum UA level was associated with a larger hematoma volume (odds ratio, 0.996; P = 0.006) and an unfavorable outcome (odds ratio, 0.997; P = 0.030).

CONCLUSIONS

The results from the present study have indicated that in patients with acute supratentorial ICH, a low serum UA level might indicate that the patient has a large hematoma volume and might be a risk factor for a poor day 30 functional prognosis.

Serum uric acid and risk of stroke: a dose-response meta-analysis

The relationship between serum uric acid and risk of stroke is still controversial. Therefore, we conducted a meta-analysis based on the cohort study to explore the relationship between serum uric acid and risk of stroke, and further illuminate whether there is a linear or non-linear relationship between them. We manually searched the database including Cochrane, PubMed, Embase, Web of Science, and selected cohort studies focusing on the relationship between serum uric acid and stroke risk. Random effect model was used for statistical analysis. Twenty-one cohort studies involving 818,098 participants were included. The pooled relative risk for the high-vs-low categories was 1.22 (95% CI: 1.15-1.30). In addition, there was a non-linear dose-response relationship between uric acid and stroke risk. Serum uric acid was in the range of 3-5 mg/dl, with the lowest risk of stroke. In conclusion, high serum uric acid level increases the risk of stroke, with a non-linear dose-response relationship.