Uric acid levels are relevant in patients with stroke treated with thrombolysis

Association of serum uric acid levels with risk of epilepsy: A national population-based study

BACKGROUND

Uric acid (UA) serves as a crucial endogenous antioxidant in the body, offering protection against oxidative stress, whichmaycontributetoepilepsypathogenesis. The association between serum UA levels and epilepsy remains uncertain. This study aimed to examine the potential connections between serum UA levels and epilepsy in US adults.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2013-2018, a cross-sectional analysis was conducted. Weighted logistic regression analyses were employed to assess the potential link between serum UA levels and the risk of epilepsy. Additionally, sensitivity analyses were conducted to evaluate the reliability of the results.

RESULTS

We included 15,373 participants, of whom 136 (0.79 %) had epilepsy. Following adjustment for multiple variables, participants with serum UA levels <4.1 mg/dl had an odds ratio of 2.24 (95 % CI: 1.12-4.47, P = 0.023) for epilepsy compared to those with serum UA levels of 5.8-6.5 mg/dl. The results of the sensitivity analyses corroborated the initial findings.

CONCLUSIONS

Our study revealed a significant association between lower serum UA levels and heightened risks of epilepsy, suggesting that low UA levels may serve as an independent risk factor for epilepsy. A marginal increase in UA levels within the normal range may act as a protective factor against epilepsy.

Association of serum uric acid to serum creatinine ratio with 1-year stroke outcomes in patients with acute ischemic stroke: A multicenter observational cohort study

BACKGROUND AND PURPOSE

Considering the reliance of serum uric acid (SUA) levels on renal clearance function, its role in stroke outcomes remains controversial. This study investigated the association of renal function-normalized SUA (SUA to serum creatinine ratio, SUA/SCr), a novel renal function index, with the 1-year outcomes in patients with acute ischemic stroke (AIS).

METHODS

This is a prospective, multicenter observational study. Renal function-normalized SUA levels were determined by calculating the ratio of SUA to SCr. One-year outcomes included stroke recurrence, all-cause mortality, and poor prognosis. Multivariable Cox regression analyses and restriction cubic splines for curve fitting were used to evaluate SUA/SCr's association with 1-year stroke outcomes.

RESULTS

Among 2294 enrolled patients, after adjustment for potential confounders, multivariable Cox regression analyses showed that each one-unit increase in SUA/SCr corresponded to a 19% decrease in 1-year stroke recurrence in patients with AIS. SUA/SCr was analyzed as a continuous variable and categorized into quartiles (Q1-Q4). Compared with the Q1 reference group, Q2, Q3, and Q4 showed significantly lower 1-year stroke recurrence risks. The trend test indicated significant differences in the 1-year stroke recurrence trend from Q1 to Q4. In these patients, SUA/SCr did not show a significant association with poor prognosis or all-cause mortality. Curve fitting revealed SUA/SCr had a negative but nonlinear association with 1-year stroke recurrence.

CONCLUSIONS

In patients with AIS, low SUA/SCr may be an independent risk factor for 1-year stroke recurrence. Changes in SUA/SCr had no significant impact on 1-year poor prognosis and all-cause mortality.

Lower serum uric acid to serum creatinine ratio as a predictor of poor functional outcome after mechanical thrombectomy in acute ischaemic stroke

BACKGROUND AND PURPOSE

The ratio of serum uric acid (SUA) to serum creatinine (SCr), representing normalized SUA for renal function, is associated with functional outcome in acute ischaemic stroke (AIS) patients. However, its effect on AIS patients undergoing mechanical thrombectomy (MT) remains unknown. This study aimed to investigate the influence of the SUA/SCr ratio on clinical outcome in MT-treated AIS patients.

METHODS

Acute ischaemic stroke patients who underwent MT were continuously enrolled from January 2018 to June 2023. Upon admission, SUA and SCr levels were recorded within the initial 24 h. Stroke severity was determined using the National Institutes of Health Stroke Scale (NIHSS) score. Clinical outcome included poor functional outcome (modified Rankin Scale score >2) at 90 days, symptomatic intracranial haemorrhage and death.

RESULTS

Amongst 734 patients, 432 (58.8%) exhibited poor functional outcome at 90 days. The SUA/SCr ratio exhibited a negative correlation with NIHSS score (ρ = -0.095, p = 0.010). Univariate analysis revealed a significant association between SUA/SCr ratio and poor functional outcome. After adjusting for confounders, the SUA/SCr ratio remained an independent predictor of functional outcome (adjusted odds ratio 0.348, 95% confidence interval 0.282-0.428, p < 0.001). Receiver operating characteristic curve analysis highlighted the ability of the SUA/SCr ratio to predict functional outcome, with a cutoff value of 3.62 and an area under the curve of 0.757 (95% confidence interval 0.724-0.788, p < 0.001).

CONCLUSION

The SUA/SCr ratio is correlated with stroke severity and may serve as a predictor of 90-day functional outcome in AIS patients undergoing MT.

The prognostic value of combined uric acid and neutrophil-to-lymphocyte ratio in acute ischemic stroke patients treated with intravenous thrombolysis

BACKGROUND

Serum uric acid (UA) and the neutrophil-to-lymphocyte ratio (NLR) have been reported to be associated with outcomes in acute ischemic stroke (AIS). However, whether UA is related to the prognosis of AIS patients undergoing intravenous thrombolysis (IVT) remains inconclusive. We sought to explore the combined effect of UA and NLR on the prognosis of AIS treated with IVT.

METHODS

A total of 555 AIS patients receiving IVT treatment were enrolled. Patients were categorized into four groups according to the levels of UA and NLR: LNNU (low NLR and normal UA), LNHU (low NLR and high UA), HNNU (high NLR and normal UA), and HNHU (high NLR and high UA). Multivariable logistic regression analysis was used to evaluate the value of serum UA level and NLR in predicting prognosis. The primary outcomes were major disability (modified Rankin scale (mRS) score 3-5) and death within 3 months.

RESULTS

After multivariate adjustment, a high NLR (≥ 3.94) increased the risk of 3-month death or major disability (OR, 2.23; 95% CI, 1.42 to 3.55, p < 0.001). However, there was no statistically significant association between a high UA level (≥ 313.00 µmol/L) and clinical outcome. HNHU was associated with a 5.09-fold increase in the risk of death (OR, 5.09; 95% CI, 1.31-19.83; P value = 0.019) and a 1.98-fold increase in the risk of major disability (OR, 1.98; 95% CI 1.07-3.68; P value = 0.030) in comparison to LNNU.

CONCLUSIONS

High serum UA levels combined with high NLR were independently associated with 3-month death and major disability in AIS patients after IVT.

Serum Uric Acid Levels and Outcome of Acute Ischemic Stroke: a Dose-Response Meta-analysis

Previous meta-analyses have reported conflicting results regarding the relationship between baseline uric acid (UA) levels and acute ischemic stroke (AIS) outcomes. Therefore, we conducted a dose-response meta-analysis to elucidate the association's strength and shape. Studies on the association between baseline UA levels and AIS outcomes in the PubMed and EMBASE databases were searched from their inception to April 17, 2023. Two researchers independently reviewed the studies for inclusion. A total of 23 articles involving 15,733 patients with AIS were included. The analysis revealed a significant inverse correlation between UA levels and AIS outcomes. The linear trend estimation indicated that a 50-μmol/L increment in UA level was associated with a 21.7% lower risk of hemorrhagic transformation (odds ratio [OR]: 0.783; 95% confidence interval [CI]: 0.743, 0.826; I2 = 43.4%; n = 4), 7.0% lower risk of 90-day unfavorable outcome [modified Rankin scale score ≥ 2] (OR: 0.930; 95% CI: 0.875, 0.990; I2 = 0%; n = 3), and 7.5% lower risk of 90-day poor outcome [modified Rankin scale score ≥ 3] (OR: 0.925; 95% CI: 0.863, 0.990; I2 = 74.4%; n = 3) in patients with AIS after accounting for relevant covariates. A linear dose-response relationship exists between baseline UA levels and the outcome of patients with AIS within a certain range, with higher baseline UA levels associated with better outcomes after AIS. Further dose-response meta-analyses, including a larger number of original articles, are required to validate our findings.

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.

Uric Acid: A Translational Journey in Cerebroprotection That Spanned Preclinical and Human Data

Uric acid (UA) is a strong endogenous antioxidant that neutralizes the toxicity of peroxynitrite and other reactive species on the neurovascular unit generated during and after acute brain ischemia. The realization that a rapid reduction of UA levels during an acute ischemic stroke was associated with a worse stroke outcome paved the way to investigate the value of exogenous UA supplementation to counteract the progression of redox-mediated ischemic brain damage. The long translational journey for UA supplementation recently reached a critical milestone when the results of the multicenter NIH stroke preclinical assessment network (SPAN) were reported. In a novel preclinical paradigm, 6 treatment candidates including UA supplementation were selected and tested in 6 independent laboratories following predefined criteria and strict methodological rigor. UA supplementation was the only intervention in SPAN that exceeded the prespecified efficacy boundary with male and female animals, young mice, young rats, aging mice, obese mice, and spontaneously hypertensive rats. This unprecedented achievement will allow UA to undergo clinical testing in a pivotal clinical trial through a NIH StrokeNet thrombectomy endovascular platform created to assess new treatment strategies in patients treated with mechanical thrombectomy. UA is a particularly appealing adjuvant intervention for mechanical thrombectomy because it targets the microcirculatory hypoperfusion and oxidative stress that limits the efficacy of this therapy. This descriptive review aims to summarize the translational development of UA supplementation, highlighting those aspects that likely contributed to its success. It includes having a well-defined target and mechanism of action, and an approach that simultaneously integrated rigorous preclinical assessment, with epidemiologic and preliminary human intervention studies. Validation of the clinical value of UA supplementation in a pivotal trial would confirm the translational value of the SPAN paradigm in preclinical research.

Serum Uric Acid Levels and Recurrence Rate of Ischemic Stroke: A Meta-Analysis

The role of serum uric acid as a factor in the recurrence of ischemic stroke stays unclear. Several studies have examined the relationship between serum uric acid and recurrence of acute ischemic stroke, with various results. Therefore, we carried out a meta-analysis to have a look at the relationship between serum uric acid levels and the potential danger of stroke recurrence in patients with ischemic stroke. Relevant experiments have been recognized via looking out the electronic databases and conference sessions. This present study included a case-control study of the impact of uric acid on the recurrence of ischemic stroke. After the assessment of eligibility, this meta-analysis included four articles in which 2452 patients with ischemic stroke were tested for their level of serum uric acid. The results obtained from this meta-analysis confirmed that improved uric acid concentrations were extensively and independently related to an accelerated and higher risk of recurrent stroke. The pooled OR (95% CI) was 1.80 (1.47, 2.20) (p<0.001). Overall, this meta-analysis shows a relationship between uric acid concentration and stroke recurrence rate. Furthermore, high uric acid levels could enhance the recurrence rate of ischemic stroke.

Serum uric acid to serum creatinine ratio predicts neurological deterioration in branch atheromatous disease

Background and objective

Branch atheromatous disease (BAD) makes patients prone to early neurological deterioration (END), resulting in poor prognosis. The aim of this study was to investigate the association between SUA/SCr and END in BAD stroke patients.

Methods

We conducted a retrospective study that included 241 patients with BAD-stroke within 48 h of symptom onset. We divided the patients into the END group and the no END group. END was defined as an NIHSS score increase of more than 2 points within 1 week. SUA/SCr was calculated by the concentration of serum uric acid and creatine (serum uric acid/serum creatine) on admission. Univariate and multivariate analyses were used to identify independent predictors of END in BAD-stroke patients.

Results

END was observed in 24.1% (58/241) of the patients in our study. Multiple logistic regression analyses showed that SUA/SCr (aOR, 0.716; 95% CI, 0.538-0.952; P = 0.022) and female sex (aOR, 0.469; 95% CI, 0.245-0.898; P = 0.022) were associated with END after adjusting for confounding factors. The predicted value of SUA/Scr for END was a sensitivity of 79.3%, a specificity of 44.8%, and an AUC of 0.609 (95% CI, 0.527-0.691, P < 0.05). The optimal cut-off value was 4.76.

Conclusion

SUA/SCr was negatively associated with the risk of END in BAD stroke patients.

J-Shaped Relationship of Serum Uric Acid with Unfavorable Short-Term Outcomes among Patients with Acute Ischemic Stroke

(1) Background: The role of uric acid in stroke outcomes remains inconclusive. (2) Methods: We retrospectively enrolled 3370 patients with acute ischemic stroke. (3) Results: Uric acid level was higher in men than in women. Univariate analyses revealed that the rates of hyperuricemia were higher in all patients and in women for unfavorable outcomes. For death, the hyperuricemia rates were higher in all patients including men and women, and the uric acid levels were also higher in all patients and in women. A J-shaped curve was observed between uric acid and the discharge-modified Rankin Scale score. Patients within Quartiles 1 (<4.1 mg/dL) and 4 (>6.5 mg/dL) of uric acid had higher rates of unfavorable outcomes and death than patients within Quartiles 2 (4.1−5.1 mg/dL) and 3 (5.1−6.2 mg/dL). Multivariable analyses for unfavorable outcomes revealed that Quartile 1 of uric acid was a significant factor in all patients and in men. In men, a significant factor for death was being in Quartile 1 of uric acid. In women, higher levels of uric acid or hyperuricemia (>6.6 mg/dL) were significant factors for death. (4) Conclusions: Lower uric acid levels are a predictor for unfavorable outcomes and death in men, and higher uric acid levels are a predictor for death in women.

Association between serum uric acid to serum creatinine ratio and poor functional outcomes in patients with acute ischemic stroke

BACKGROUND

The role of serum uric acid (SUA) in prognosis is controversial because SUA levels largely depend on renal clearance function. This study aimed to investigate the association between renal function-normalized SUA (SUA to serum creatinine ratio, SUA/SCr) and poor functional outcomes in patients with acute ischemic stroke (AIS).

METHODS

All patients were recruited from the Third China National Stroke Registry. Poor functional outcomes were defined by modified Rankin Scale (mRS) scores of 3-6 at 3 months or 2-6 at 1 year.

RESULTS

Among 8169 enrolled patients, the median SUA/SCr was 4.19 (interquartile range, 3.47-5.08). Compared with patients in the fourth quintile group, those in the first quintile group had higher proportions of mRS score 3-6 (odds ratio [OR] 1.55; 95% confidence interval [CI] 1.24-1.93) and mRS score 2-6 (OR 1.28; 95% CI 1.08-1.53) at 3 months. The addition of SUA/SCr to the conventional risk model had a greater incremental value than the addition of SUA or SCr alone. Subgroup analysis showed that the association was only significant in patients with normal kidney function (P for interaction<0.05). Similar results were found for outcomes at 1 year.

CONCLUSIONS

A lower level of SUA/SCr was associated with poor functional outcomes in patients with AIS at 3 months and at 1 year, suggesting the potential use of SUA/SCr in clinical practice as a preferable marker for stroke outcomes.

The Prognostic Value of Serum Uric Acid in Hospitalized Patients with Acute Cerebral Infarction

Background

Previous studies reported that the level of serum uric acid (SUA) was an important risk factor for acute cerebral infarction (ACI). However, the prognostic value of SUA levels in hospitalized patients with ACI has not been fully elucidated. The aim of this study was to investigate whether the SUA level on admission was associated with subsequent mortality in hospitalized patients with ACI.

Methods

The clinical data of ACI patients obtained from December 2017 to December 2019 were retrospectively reviewed. χ² and Kaplan–Meier methods were used to compare the clinical differences and overall survival between patients with or without hyperuricemia, respectively. Univariate and multivariate analyses were used to identify independent prognoses.

Results

In the total population, the in-hospital mortality of the hyperuricemia group was significantly higher than that of the normal uric acid group (P = 0.006). In the abnormal renal function group, the in-hospital mortality among the hyperuricemia group was significantly higher than the normal uric acid group (P = 0.002). However, there was no statistical difference of in-hospital mortality between the two groups in the normal renal function group (P = 0.321). Univariate and multivariate analyses showed that a previous history of diabetes (P = 0.018), hyperuricemia (P = 0.001), and National Institutes of Health Stroke Scale (NIHSS) score on admission (P ≤ 0.001) were independent factors for all samples. The hyperuricemia (P = 0.003) on admission were independent factors for patients with abnormal renal function.

Conclusions

In ACI patients with abnormal renal function, hyperuricemia may be associated with higher in-hospital mortality than patients with normal uric acid, and hyperuricemia may be an independent associated factor for in-hospital death in the subgroup patients.

Uric acid played a role in the association between gender and deep vein thrombosis in patients with stroke

BACKGROUND AND AIMS

Gender-specific differences were found in serum uric acid (SUA) levels and the risk of isolated distal deep vein thrombosis (IDDVT). This study aimed to explore the association among gender, SUA, and IDDVT in stroke patients.

METHODS AND RESULTS

Finally, 3404 patients were recruited and divided into two groups: IDDVT (n = 1233) and Non-IDDVT (n = 2171) groups. Propensity score matching (PSM) was conducted to match the patients. Binary logistic regression was adopted to explore the association between SUA and IDDVT, with the SUA divided into quartiles. After PSM, 975 patients were included in each group. Non-IDDVT group had a larger proportion of male than IDDVT group (64.9% vs. 52.7%, p < 0.001). Moreover, males showed higher SUA levels than females (316.7 ± 102.1 vs. 261.8 ± 94.0 μmol/L, t = 12.1, p < 0.001). The highest quartile of SUA (≥346 μmol/L) showed a lower risk of IDDVT (OR = 0.629, p = 0.001), while the lowest quartile (≤225 μmol/L) showed a higher risk of IDDVT (OR = 1.361, p = 0.022).

CONCLUSION

In patients with stroke, SUA played a protective role in IDDVT. Females had a higher risk of IDDVT, which may be owing to the lower SUA levels than males. In clinical practice, more attention should be paid to the risk of IDDVT in females, especially those with lower SUA levels.

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.

Uric Acid and Gluconic Acid as Predictors of Hyperglycemia and Cytotoxic Injury after Stroke

Hyperglycemia is a feature of worse brain injury after acute ischemic stroke, but the underlying metabolic changes and the link to cytotoxic brain injury are not fully understood. In this observational study, we applied regression and machine learning classification analyses to identify metabolites associated with hyperglycemia and a neuroimaging proxy for cytotoxic brain injury. Metabolomics and lipidomics were carried out using liquid chromatography-tandem mass spectrometry in admission plasma samples from 381 patients presenting with an acute stroke. Glucose was measured by a central clinical laboratory, and a subgroup of patients (n = 201) had apparent diffusion coefficient (ADC) imaging quantified on magnetic resonance imaging (MRI) to estimate cytotoxic injury. Uric acid was the leading metabolite in univariate analysis of both hyperglycemia (OR 19.6, 95% CI 8.6-44.7, P = 1.44 × 10-12) and ADC (OR 5.3, 95% CI 2.2-13.0, P = 2.42 × 10-4). To further prioritize model features and account for non-linear correlation structure, a random forest machine learning algorithm was applied to separately model hyperglycemia and ADC. The statistical techniques used have identified uric acid and gluconic acids as leading candidate markers common to all models (R2 = 68%, P = 2.2 × 10-10 for uric acid; R2 = 15%, P = 8.09 × 10-10 for gluconic acid). Both uric acid and gluconic acid were associated with hyperglycemia and cytotoxic brain injury. Both metabolites are linked to oxidative stress, which highlights two candidate targets for limiting brain injury after stroke.

Prognostic significance of uric acid change in acute ischemic stroke patients with reperfusion therapy

BACKGROUND

Uric acid (UA) is an important endogenous free radical scavenger that has been found to have a neuroprotective effect. However, there is uncertainty about the relationship between UA change and outcome in acute ischemic stroke (AIS) patients with reperfusion therapy.

METHODS

We consecutively enrolled AIS patients with reperfusion therapy. UA was measured upon admission and during hospitalization. The change in UA levels (ΔUA) was determined by calculating the difference between admission UA and the lowest UA among all follow-up measurements, with a positive ΔUA suggesting a decrease in UA levels. Functional outcome was assessed by modified Rankin Scale (mRS) at 3 months. Poor outcome was defined as mRS >2.

RESULTS

A total of 361 patients were included (mean age 68.7 ± 13.9 years, 54.3% males). The mean UA on admission was 355 ± 96.1 μmol/L. The median ΔUA was 121 μmol/L (IQR 50-192 μmol/L) and 18 (5%) patients had increased UA levels. UA on admission was positively associated with good outcome (p for trend = 0.017). When patients were classified into quartiles by ΔUA, patients with the largest decrease in UA (Q4: 199-434 μmol/L) had a higher risk of poor outcome at 3 months compared to patients with the least decrease in UA (Q1: 0-57 μmol/L) (OR 2.55, 95% CI 1.09-5.98, p = 0.031). The risk of poor outcome increased with ΔUA (p for trend = 0.048).

CONCLUSIONS

In patients with reperfusion therapy, high UA on admission was associated with a good 3-month outcome, while a greater decrease in UA was associated with poor outcome.

Higher uric acid is associated with better discharge recovery and short-term outcome in stroke patients treated with thrombolysis

BACKGROUND

Uric acid (UA) possesses antioxidant features and potential neuroprotective effects. However, conflicting results regarding the association between serum uric acid (SUA) levels and the prognosis of stroke have been obtained. We aimed to assess whether SUA is related to discharge recovery and short-term outcomes in patients who underwent thrombolysis therapy.

METHODS

We recruited 393 consecutive patients who were diagnosed with acute ischaemic stroke (AIS) and treated with thrombolysis. The demographic information, including sex and age, was collected. Haematology tests, including SUA, fasting plasma glucose (FPG), and blood lipid parameters, were performed under fasting conditions the morning after admission. The modified Rankin Scale (mRS) was used to assess the functional outcome of patients at discharge and 3 months after onset.

RESULTS

A negative correlation was observed between the levels of SUA and the National Institute of Health Stroke Scale (NIHSS) score at discharge (r = - 0.171, P = 0.003). Additionally, a positive correlation was observed between the levels of SUA and the difference between the baseline NIHSS and discharge NIHSS (r = 0.118, P = 0.032). The levels of SUA in the patients with good outcomes (353.76 ± 93.05) were higher than those in the patients with poor outcomes (301.99 ± 92.24; P = 0.015) at 3 months. The multivariate logistic regression analysis demonstrated that a higher SUA level (odds ratio 0.988, 95% confidence interval 0.985-0.991, P = 0.002) was an independent predictor of a good outcome at 3 months.

CONCLUSION

Higher SUA levels were associated with better discharge recovery and 3-month outcomes in patients with ischaemic stroke who received thrombolysis.

Lower uric acid level may be associated with hemorrhagic transformation but not functional outcomes in patients with anterior circulation acute ischemic stroke undergoing endovascular thrombectomy

To determine the correlation of uric acid (UA) with hemorrhagic transformation (HT) and poor short-term functional outcomes in anterior circulation acute ischemic stroke (AIS) patients after endovascular thrombectomy (EVT). A retrospective analysis was conducted for anterior circulation AIS patients who underwent EVT at our hospital from 2015 to 2019. HT within 72 h was documented according to the European Cooperative Acute Stroke Study II Classification. Baseline demographic, clinical and laboratory data were compared between the HT and non-HT groups, and between patients with favorable and unfavorable outcomes on 90-day. A total of 247 AIS patients were enrolled, of which 92 (37.2%) and 85 (34.4%) experienced HT and had favorable functional outcomes at 3 months respectively. Patients with HT had significantly lower UA levels compared to those without HT (322.60 ± 94.49 vs. 350.25 ± 99.28 μmol /L, P = 0.032). In contrast, UA levels were similar in patients with good or poor outcomes (345.67 ± 103.55 vs. 336.95 ± 95.5 μmol /L, P = 0.509). Compared to the patients with UA levels in the first quartile, those in the fourth quartile were at a higher risk of HT in univariate logistic regression analysis (OR = 0.383, 95% CI = 0.173-0.848, P = 0.018). The association remained significant after multivariable adjustment for potential confounders. A lower UA level is an independent risk factor of HT post-EVT in anterior circulation AIS patients, but is not associated with the short-term functional outcomes.

Effect of renal function on association between uric acid and prognosis in acute ischemic stroke patients with elevated systolic blood pressure

BACKGROUND AND AIMS

The prognostic value of uric acid in ischemic stroke remains controversial, and it is unclear whether renal function status modifies the prognostic value of uric acid in ischemic stroke patients.

METHODS

A total of 3284 acute ischemic stroke patients from the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS) with creatinine and uric acid measurements were included in this analysis. The primary outcome was a composite of death and major disability (modified Rankin Scale score ≥3) at 1 year after stroke.

RESULTS

The prognostic value of uric acid in ischemic stroke was appreciably modified by patients' renal function status (p for interaction <0.05). After multivariate adjustment, higher uric acid level was significantly associated with a better prognosis in patients with normal renal function (odds ratio, 0.61; 95% confidence interval, 0.45-0.83), but not in those with abnormal renal function (odds ratio, 0.87; 95% confidence interval, 0.48-1.55), when two extreme quartiles were compared. Linear association between uric acid and primary outcome was observed among patients with normal renal function (p for linearity = 0.023).

CONCLUSION

The present study suggests that high serum uric acid concentration is associated with better prognosis in ischemic stroke patients with normal renal function, but not in those with abnormal renal function. The establishment of causality between increased uric acid levels and better stroke prognosis needs more suitably designed randomized clinical trials.

Relationship between Uric Acid Level and Severity of Acute Primary Cerebral Infarction: A Cross-Sectional Study

Numerous studies have shown that uric acid (UA) is associated with cerebrovascular disease, but whether UA is a protective factor or worsens the risk of developing cerebrovascular disease remains controversial. This study investigated the relationship between UA levels detected at admission and the severity of acute primary cerebral infarction. This cross-sectional study enrolled patients with acute primary cerebral infarction (N = 238, 157 men). We designated the levels of serum UA measured at the time of admission as the independent variable and the degree of neurological impairment at admission as the dependent variable. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the extent of neurological dysfunction: NIHSS ≤ 5, minor stroke; NIHSS > 5, moderate to severe stroke. There was a statistically significant difference in UA levels between patients with mild cerebral infarctions (NIHSS ≤ 5) and those with moderate or severe cerebral infarctions (NIHSS > 5) (P < 0.0001). After adjusting for confounding factors, the serum UA level was found to be nonlinearly related to NIHSS, and the inflection point was 372 μmol/L. The extent of the influence and confidence interval was 0.99 (0.98, 0.99) on the left side of the inflection point and 1.00 (1.00, 1.01) on the right side. There was a nonlinear relationship between the UA level measured on admission and the degree of neurological impairment in patients with acute primary cerebral infarction. When UA was <372 μmol/L, it was negatively correlated with the degree of neurological impairment in patients with acute cerebral infarction, but when UA was ≥372 μmol/L, the protective effect of UA disappeared.

Serum Uric Acid Level and Outcome of Patients With Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

The issue of whether serum uric acid (SUA) is associated with the outcome of acute ischemic stroke is controversial. This study aimed to evaluate the correlation between the SUA level and outcome of patients with ischemic stroke by performing a meta-analysis.

MATERIALS AND METHODS

Studies were included by a systematic search of several databases through December 01, 2018, followed by reviewing reference lists of obtained articles. Studies that included odds ratios (ORs) for ischemic stroke outcome per unit SUA level with 95% confidence intervals (95% CIs) were eligible for the meta-analysis. A random-effects model was used to calculate the pooled risk estimate. Publication bias was detected by Begg's test.

RESULTS

Fifteen studies with a total of 12,739 cases of stroke were included. Overall, higher SUA levels were associated with a significantly better outcome of ischemic stroke (OR, 1.13; 95% CI, 1.07-1.18; P<0.00001). For patients receiving thrombolytic therapy, a subgroup meta-analysis showed a positive association between SUA level and patient outcome (OR, 1.26; 95% CI, 1.14-1.40; P<0.00001). In addition, the pooled estimate of patients with a modified Rankin Scale score ≤2 at 90 days also showed a positive association (OR, 1.07; 95% CI, 1.01-1.133; P<0.00001). Furthermore, we found that the average SUA level in patients with a good outcome was higher than in those with a poor outcome (mean difference, 0.24 µmol/L; 95% CI, 0.16-0.32; P<0.00001).

CONCLUSIONS

This meta-analysis suggested that there was a significant positive association between SUA level and the outcome of ischemic stroke.

Uric Acid Contributes to Obesity-Paradox of the Outcome of Ischemic Stroke

Background: The mechanism of obesity paradox in stroke is not clear. This study aimed to investigate whether uric acid (UA) contributes to obesity-stroke outcome paradox.

Material and Methods: The study cohort consisted of 1,984 IS patients recruited in the ACROSS-China study. Serum UA and BMI were measured at admission. Low and high BMI groups were defined by the threshold of 24, and low and high UA by the age- and sex-specific median. Poor outcomes were defined as modified Rankin scale score ≥3 in 1 year after onset.

Results: UA was significantly and positively correlated with BMI. Lower levels of UA and BMI were significantly associated with higher risk of poor outcomes. Incidence of the poor outcome was 34.5, 29.4, 27.7, and 23.5% in the BMI/UA groups of low/low, high/low, low/high and high/high, respectively, with p = 0.001 for trend. The association between low UA and poor outcome was significant in lower BMI groups (odds ratio = 1.36, p = 0.006 in quartile 1 and 1.28, p = 0.021 in quartile 2), but the odds ratios were not significant in the BMI quartile 3 and 4 groups, with p = 0.038 for trend. The adverse effect of lower UA was significant in males, but not in females, with p = 0.006 for sex difference.

Conclusions: These findings suggest that low UA and low BMI have a joint effect on poor outcomes in IS patients. Across BMI categories, uric acid is differentially associated with functional outcome after stroke. This effect of low UA in the low BMI groups may be one of the mechanisms underlying the obesity-stroke paradox of the outcome in IS patients.

Serum Uric Acid - Risk Factor for Acute Ischemic Stroke and Poor Outcomes

Over the last decades several studies among the adult population have attempted to establish a correlation between the risk of stroke incidence and serum uric acid (SUA) concentration, and how these levels influence the patient’s neurological outcome after a stroke. But, to date, the results are conflicting. In this review, an extensive literature search was performed through PubMed for articles published until May 2019 to review the association. The study selection was narrowed by searching PubMed database using the Medical Subject Headings (MesH) and associated keywords. Only articles conducted in English and on human subjects were included. We considered an article for this review if it had statistics on either the incidence, stroke mortality or post-stroke functional outcomes along with serum uric acid levels in adults.

This review includes 21 articles with data of 33,580 cases of stroke and 1,100,888 participants. We can divide the articles reviewed into two separate cohorts of studies. One relates serum uric acid levels to stroke frequency and mortality, while the other is associated with serum uric acid and outcomes for stroke survivors. Based on our review, no significant relationship is observed with uric acid exhibiting protective effects on stroke outcome. Large clinical trials are advised to provide well-defined solutions to further assess the benefits of uric acid level lowering treatment in patients of vascular events, such as a stroke. However, we confidently report that increasing uric acid levels poses a higher risk for incidence of stroke.

Serum Uric Acid and Risk of Hemorrhagic Transformation in Patients with Acute Ischemic Stroke

Uric acid (UA) is an antioxidant with neuroprotective effects in experimental stroke models. Whether serum UA plays a role in hemorrhagic transformation (HT) remains unclear. We aimed to explore the association between serum UA and HT in patients with acute ischemic stroke (AIS). AIS patients within 7 days after stroke onset were consecutively enrolled between January 2016 and October 2017. Patients were categorized into three groups according to serum UA tertiles by sex. HT was detected by follow-up CT or MRI within 7 days after admission. The multivariate logistic analysis was performed to assess the association of serum UA with HT. We included 1230 patients (mean age 64.1 years, 63.5% males) and 133 (10.8%) patients experienced HT. After adjusting confounders, patients in the second and third UA tertiles showed a significant decrease in HT compared with those in the lowest tertile (OR 0.432, 95% CI 0.266-0.702; OR 0.033, 95% CI 0.013-0.086, respectively). Similar results were observed for sex-based subgroups. Males with higher UA had lower risk of HT compared with the lowest UA tertile (OR 0.332, 95% CI 0.170-0.651; OR 0.008, 95% CI 0.001-0.070, respectively). In females, the highest UA tertile was inversely associated with HT (OR 0.148, 95% CI 0.058-0.376). Multiple-adjusted spline regression analyses further confirmed the dose-response relationship between UA levels and HT. Higher serum UA is independently associated with lower HT following stroke. More studies are needed to elucidate the potential neuroprotective mechanism of serum UA and its link to HT.

Association between serum uric acid and large-nerve fiber dysfunction in type 2 diabetes: a cross-sectional study

Background

Large-nerve fiber dysfunction, as assessed by vibration perception threshold (VPT) predicts risks of ulceration, amputation, and mortality in diabetes. Serum uric acid (UA) is closely associated with various metabolic disorders, especially diabetes. Thus, we sought to investigate the clinical relevance of UA to large-nerve fiber dysfunction, among patients with type 2 diabetes (T2D).

Methods

Medical records of consecutive patients with T2D who were admitted to Beijing Friendship Hospital Pinggu Campus between May 2014 and December 2016 were collected. Data for the 824 eligible patients included in the final analysis were extracted using a structured form. A VPT value ≥15 in either foot was defined as abnormal. We compared the clinical characteristics between patients with abnormal VPT and those with normal VPT (VPT value <15 in both feet) in the overall population and in gender subgroups. Logistic regression analysis was performed to explore the association of abnormal VPT with UA level. One-way analysis of variance was used to compare VPT values across four UA quartiles.

Results

UA levels were significantly lower in T2D patients with abnormal VPT than in those with normal VPT (294.5 ± 84.0 vs. 314.9 ± 92.8 μmol/L, P < 0.01), especially among male patients (311.7 ± 85.2 vs. 336.9 ± 89.6 μmol/L, P < 0.01). From the logistic regression analysis, hyperuricemia (males >420 μmol/L; females >360 μmol/L) was associated with a reduced risk of abnormal VPT (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.39–0.91; P < 0.05). This association was robust in male patients (OR, 0.43; 95% CI, 0.24–0.76; P < 0.01) but not in female patients (OR, 0.92; 95% CI, 0.47–1.82; P = 0.816), even after adjustment for confounding factors. For the younger male subgroup (age <65 years), VPT values decreased as the UA level increased (P for trend = 0.002), but this trend was not significant in older male subgroup (age ≥65 years; P for trend = 0.400).

Conclusions

Low serum UA levels showed a significant association with an increased risk of large-nerve fiber dysfunction in male patients with T2D, but not in female patients with T2D. In addition, in only the younger subgroup of male patients (<65 years), lower levels of UA also correlated with higher VPT values.

Effects of Urinary Kallidinogenase on NIHSS score, mRS score, and fasting glucose levels in acute ischemic stroke patients with abnormal glucose metabolism: A prospective cohort study

Urinary kallidinogenase may assist recovery acute ischemic stroke. This study evaluated the effect of urinary kallidinogenase on National Institute of Health Stroke Scale (NIHSS) score, modified Rankin scale (mRS) score, and fasting glucose levels in patients with acute ischemic stroke (AIS) combined with diabetes mellitus and impaired fasting glucose.Patients with AIS and abnormal glucose metabolism were enrolled in this prospective cohort study and divided into 2 groups. The human urinary kallidinogenase (HUK) group were treated with urinary kallidinogenase and standard treatment; the control group received standard treatment. NIHSS scores, mRS scores, and fasting blood glucose were evaluated and compared.A total of 113 patients were included: 58 in the HUK group and 55 in the control group. NIHSS scores decreased with treatment in both groups (time effect P < .05), but were lower in the HUK group (main effect P = .026). The mRS score decreased in both groups from 10 until 90 days after treatment (time effect P < .05); the 2 groups were similar (main effect, P = .130). Blood glucose levels decreased in both groups 10 days after treatment (time effect, P < .05), but there was no significant treatment effect (main effect, P = .635). Multivariate analysis showed blood uric acid >420 μmol/L (odds ratio [OR]: 0.053, 95% confidence interval [CI]: 0.008-0.350; P = .002) and application of HUK (OR: 0.217, 95% CI: 0.049-0.954; P = .043) were associated with 90% NIHSS recovery. Baseline NIHSS score was independently associated with poor curative effect.Urinary kallidinogenase with conventional therapy significantly improved NIHSS scores in patients with AIS. Urinary kallidinogenase also showed a trend toward lower fasting blood glucose levels, although the level did not reach significance.

The prognostic value of serum uric acid in the acute phase of hemorrhagic stroke patients in black Africans

Introduction

Very few studies have been conducted to evaluate the prevalence of hyperuricemia and its impact on the prognosis amongst acute hemorrhagic stroke (AHS) patients. The objectives was to determine the prevalence of hyperuricemia in AHS patients and examined the association between hyperuricemia and stroke outcomes in the Douala General Hospital (DGH).

Methods

This was a hospital based prospective cohort which included AHS patients with baseline SUA levels and 3 months post stroke follow-up data. SUA values were divided into quintiles. Associations between hyperuricemia and stroke outcomes were analyzed using multiple logistic regression and survival analysis (cox regression and Kaplan Meier).

Results

A total of 221 AHS patients were reviewed with a mean age of 55.8±11.8 years. The prevalence of hyperuricemia among AHS patients was 34.4% with mean SUA level of 376.8±131.9 μmol/l. On multivariate analysis, hyperuricemia was not independently associated with early death [(OR = 1.072 (CI: 0.370-3.056; p = 0.897)] and poor functional outcome [(OR=2.487 (CI: 0.771-8.699; p = 0.154)] after hemorrhagic stroke. No significant increase in stroke deaths was observed across higher SUA quintiles amongst hemorrhagic stroke patients (p = 0.326). No statistically significant correlation was observed between SUA level and NIHSS (r = 0.063, p = 0.353) and between SUA level and mRS (r = 0.030, p = 0.662) in hemorrhagic stroke.

Conclusion

About one third of patients present with hyperuricemia in the acute phase of hemorrhagic stroke. Hyperuricemia can act as risk factor for stroke because of its relationship with CVRFs but hyperuricemia has no impact on the severity and short-term outcome amongst black African hemorrhagic stroke patients.

Relationship between infarct size and serum uric acid levels during the acute phase of stroke

Introduction

Uric acid has gained considerable attention as a potential neuroprotective agent in stroke during the last decades, however, its role in the pathophysiology of ischemic stroke remains poorly understood. A serial evaluation of uric acid levels during the acute phase of stroke and its association with infarct size on magnetic resonance imaging is lacking.

Methods

We present a cohort study of 31 patients with ischemic stroke who were not candidates for thrombolysis according to current criteria at the time. We performed daily measurements of serum uric acid and total antioxidant capacity of plasma during the first week after symptoms onset and 30 days after. Infarct size was determined in the acute phase by a DWI sequence and the final infarct size with a control MRI (FLAIR) at day 30.

Results

Uric acid significantly decreases between days 2 to 6 compared to day 1, after adjustment by sex, age and DWI at diagnosis, with a nadir value at 72h. A mixed model analysis showed a negative association between DWI at diagnosis and uric acid evolution during the first week after stroke. Moreover, multivariable linear regression of uric acid values during follow up on DWI volumes demonstrated that DWI volume at diagnosis is negatively associated with uric acid levels at day 3 and 4. There were no significant associations between total antioxidant capacity of plasma and DWI at diagnosis, or FLAIR at any point.

Discussion

Patients with larger infarcts exhibited a significant decrease in serum uric acid levels, accounting for a more prominent reactive oxygen species scavenging activity with subsequent consumption and decay of this antioxidant. The different kinetics of total antioxidant capacity of plasma and serum uric acid levels suggests a specific role of uric acid in the antioxidant response in ischemic stroke.

Urate and risk of Alzheimer's disease and vascular dementia: A population-based study

INTRODUCTION

Low serum urate (sU) has been suggested to increase the risk of dementia since a reduction might impair antioxidant capacity. On the other hand, high sU is associated with increased cardiovascular risk which might increase the risk of dementia, especially for vascular dementia.

METHODS

In 1968-1969, a population-based sample of 1462 women aged 38 to 60 years was examined and were followed up over 44 years (mean 33.1 years). We examined whether sU (determined in 1968-1969 and 1992-1994) is associated with risk of late-life dementia.

RESULTS

During 44 years of follow-up, a higher sU (per standard deviation of 76.5 μmol/L) was associated with lower risk for dementia (n = 320; hazard ratio [HR] 0.81; confidence interval [CI] 0.72-0.91), Alzheimer's disease (n = 152; HR 0.78; CI 0.66-0.91), and vascular dementia (n = 52; HR 0.66; CI 0.47-0.94).

DISCUSSION

Our findings support the hypothesis that sU has a protective role in the development of dementia, regardless of dementia subtype. This may have important implications in the treatment of dementia and treatment goals for hyperuricemia in patients with gout.

Hyperuricemia and prognosis of acute ischemic stroke in diabetic patients

OBJECTIVES

The relationship between hyperuricemia (HUA) and prognosis of acute ischemic stroke (AIS) is unclear. This prospective cohort study aims to evaluate potential value of HUA as a prognostic factor for AIS independent of diabetic status.

METHODS

A total of 1041 consecutive patients aged from 25 to 96 with AIS were included. 340 (32.7%) had diabetes and 246 (23.6%) had HUA. Diabetic patients were stratified by gender or age. Multivariate logistic regression was used to analyse the association between HUA and prognosis of AIS.

RESULTS

HUA independently predicted poor discharge outcome of AIS in diabetic patients [OR (95% CI): 2.061 (1.042-4.077), p < 0.05]. Among diabetics, HUA selectively predicted a poor functional outcome of AIS at discharge in patients aged ≤75 years [OR (95% CI): 2.381 (1.115-5.085), p < 0.05]. Furthermore, in patients aged ≤75 years, HUA independently predicted poor discharge outcome of AIS in male diabetics [OR (95% CI): 2.684 (1.001-7.200), p < 0.05]. No association between HUA and prognosis of AIS was observed at 3-month, 6-month and 12-month follow-up, either in diabetics or nondiabetics.

CONCLUSIONS

HUA independently predicted poor in-hospital outcome of AIS in diabetic patients, especially in patients aged ≤ 75 years.

Association between serum uric acid and carotid disease in patients with atherosclerotic acute ischemic stroke

Aim

The role of serum uric acid in ischemic stroke is controversial. On the one hand, it has a role as neuroprotectant in acute phase, but on the other hand, it may promote atherosclerosis in carotid arteries. Our aim is to investigate the association of serum uric acid levels at admission of acute ischemic stroke patients with carotid disease.

Methods

Cross-sectional study of patients admitted due to acute ischemic stroke. Clinical and laboratory variables were recorded. The carotid disease was defined based on the findings of carotid echography intima to media thickness and stenosis. Patients were grouped according to these findings. Robust statistical methods were applied into analysis.

Results

A total of 245 patients were recruited through a stroke registry. Their values of serum uric acid were related to both carotid intima to media thickness and stenosis showing a positive relationship between serum uric acid levels and intima to media thickness by Pearson correlation ( p < 0.05). Similarly, after adjusting for all potential confounders, eGFR, glucose, age and serum uric acid levels, (OR 1.26 (95% CI 1.04 −1.52, p¼0.01), were identified as independent predictors for having a intima to media thickness ≥1 mm. Similarly, by grouping patients in tertiles of the serum uric acid distribution, we found a predominantly greater carotid disease in the tertile with the highest levels of serum uric acid ( p < 0.005).

Conclusion

Our study supports the hypotheses that serum uric acid levels have different roles in the case of ischemic stroke. Its effects on the vascular wall contribute to the development of atherosclerosis and carotid disease.

Relationship of Serum Uric Acid Level with Demographic Features, Risk Factors, Severity, Prognosis, Serum Levels of Vitamin D, Calcium, and Magnesium in Stroke

Introduction

Stroke is one of the most common neurological disorders with high mortality rates. A large financial burden is imposed on the families and health systems of countries in addition to the problems related to the disabilities caused by the disease for the patients. Extensive research is being conducted on the disease, including studies seeking possible relationships between some biomarkers such as uric acid and stroke.

Methods

This descriptive-analytic cross-sectional study was conducted on 170 stroke patients at Babol Ayatollah Rohani Hospital during 2015-2016. Serum uric acid (SUA) levels were measured and recorded at admission time. Patients' demographic data as well as the stroke type and some of their risk factors were entered in a checklist. The data were analyzed by SPSS.v.23 using chi-square and logistic regression tests. P < 0.05 was considered as significant in all analyses.

Results

Of the total 170 included patients, 57% had normal, 25% had low, and the remaining patients (18%) had high SUA levels. There was no significant difference in SUA levels in different types of stroke in both genders. Diabetic ischemic embolic patients had higher levels of SUA than diabetic ischemic thrombotic cases. Patients with low magnesium levels had higher rate of low levels of SUA in ischemic stroke.

Conclusion

Serum uric acid levels are not associated with stroke types and gender. Diabetic embolic ischemic stroke cases had high SUA levels than thrombotic types and in ischemic stroke patients with low serum levels of magnesium, SUA levels were also lower.

Serum Uric Acid Is Highly Associated with Epilepsy Secondary to Cerebral Infarction

In this study, we examined the association between serum uric acid levels and epilepsy secondary to cerebral infarction. Clinical data including age, gender, epileptic seizure type, imaging, and serum uric acid levels before and after seizures in patients with cerebral infarction that were collected and analyzed. One hundred patients with cerebral infarction but without epilepsy, 147 patients with epilepsy secondary to cerebral infarction, and 55 patients with status epilepticus secondary to cerebral infarction were recruited. Interestingly, epilepsy secondary to cerebral infarction was associated with both reduced uric acid (adjusted OR 2.09; 95% CI 1.07-4.08) and increased uric acid (adjusted OR 4.05; 95% CI 1.99-8.25); however, status epilepsy secondary to cerebral infarction was only associated with increased uric acid (adjusted OR 2.60; 95% CI 1.05-6.45). A U-shaped association between uric acid levels and seizures was observed by using a multivariable logistic regression model with restricted cubic spline. Serum uric acid levels are associated with both epilepsy secondary to cerebral infarction and status epilepticus secondary to cerebral infarction in patients with cerebral infarction. The appropriate intervention of serum uric acid level might be a therapeutic strategy to reduce epileptic seizures or inhibit the development of status epilepticus.

Associations between Uric Acid Level and 3-Month Functional Outcome in Acute Ischemic Stroke Patients Treated with/without Edaravone

BACKGROUND

Uric acid (UA), an antioxidant with neuroprotective effects, favorably affects stroke outcome. However, the effect has not been examined in patients treated with edaravone, a frequently used free radical scavenger. We investigated whether the use of edaravone affected the relationship between UA levels and outcome in acute ischemic stroke.

METHODS

We retrospectively evaluated 1,114 consecutive ischemic stroke patients with premorbid modified Rankin Scale (mRS) scores <2 admitted within 24 h of onset (mean, 74 years; median UA levels, 333 μmol/L). We divided the patients into 2 groups using the median UA value as a cutoff, a low UA group (≤333 μmol/L; n = 566) and a high UA group (>333 μmol/L; n = 548), and compared their clinical characteristics and favorable outcomes (mRS <2) at 90 days. We investigated the associations between UA levels and 90-day stroke outcome in patients with and without edaravone treatment.

RESULTS

The high UA group had a higher proportion of men, hypertension, atrial fibrillation, and cardioembolic stroke than the low UA group. The high UA group also had a higher proportion of patients with mRS <2 at 90 days (61.5 vs. 54.1%, p = 0.013), but the significance was diminished in multivariate analysis (OR 1.30, 95% CI 0.94-1.71). In subgroup analysis, the high UA group without edaravone exhibited a higher proportion of patients with mRS <2 at 90 days than the low UA group (OR 2.87, 95% CI 1.20-7.16). The high UA group with edaravone did not exhibit this difference.

CONCLUSIONS

In acute ischemic stroke, the favorable association between high UA levels and outcome at 90 days was not evident in patients treated with edaravone.

Hyperuricaemia as a prognostic factor for acute ischaemic stroke

INTRODUCTION

Recent studies on uric acid as a biomarker for the prognosis of acute stroke have found conflicting results.

METHODS

We collected blood samples from 600 consecutively admitted patients at our tertiary hospital and analysed the relationship between uric acid levels and functional prognosis (measured using the modified Rankin Scale [mRS]). Patients who had received reperfusion therapy were excluded since this may have influenced uric acid levels.

RESULTS

A total of 73% of patients had mRS scores ≤2; the mean uric acid level was 5.22mg/dL. We found a nonlinear relationship between functional prognosis at discharge and serum uric acid levels at admission when the National Institutes of Health Stroke Scale score was excluded from the analysis.

CONCLUSIONS

Serum uric acid levels in patients with acute ischaemic stroke are significantly associated with functional prognosis at discharge, although this relationship is nonlinear. In fact, poorer prognosis is associated both with very low and with very high concentrations of uric acid. This suggests a dual role of uric acid in relation to stroke: on the one hand, as an associated risk factor, and on the other, as a possible neuroprotective factor due to its antioxidant effect.

High serum uric acid levels are a protective factor against unfavourable neurological functional outcome in patients with ischaemic stroke

Objective

We aimed to evaluate the association between serum uric acid levels at the onset and prognostic outcome in patients with acute ischaemic stroke.

Methods

We retrospectively analysed the outcomes of 1166 patients with ischaemic stroke who were hospitalized in our centre during August 2008 to November 2012. Correlations of serum uric acid levels and prognostic outcomes were analysed.

Results

Men had higher serum uric acid levels and better neurological functional outcomes compared with women. There was a strong negative correlation between serum uric acid levels and unfavourable neurological functional outcomes. Generalized estimated equation analysis showed that a higher serum uric acid level (>237 µmol/L) was a protective factor for neurological functional outcome in male, but not female, patients. Among five trial of ORG 10172 in acute stroke treatment classification subtypes, only patients with the large-artery atherosclerosis subtype had a significant protective effect of serum uric acid levels on neurological outcome.

Conclusions

Our study shows that high serum uric acid levels are a significant protective factor in men and in the large-artery atherosclerosis subtype in patients with ischaemic stroke. This is helpful for determining the prognostic value of serum uric acid levels for neurological outcome of acute ischaemic stroke.

Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy

Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury) has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.

Baicalin Attenuates Blood-Brain Barrier Disruption and Hemorrhagic Transformation and Improves Neurological Outcome in Ischemic Stroke Rats with Delayed t-PA Treatment: Involvement of ONOO--MMP-9 Pathway

Tissue plasminogen activator (t-PA) has a restrictive therapeutic window within 4.5 h after ischemic stroke with the risk of hemorrhagic transformation (HT) and neurotoxicity when it is used beyond the time window. In the present study, we tested the hypothesis that baicalin, an active compound of medicinal plant, could attenuate HT in cerebral ischemia stroke with delayed t-PA treatment. Male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 4.5 h and then continuously received t-PA infusion (10 mg/kg) for 0.5 h and followed by 19-h reperfusion. Baicalin (50, 100, 150 mg/kg) was administrated via femoral vein at 4.5 h after MCAO cerebral ischemia. Delayed t-PA infusion significantly increased the mortality rate, induced HT, blood-brain barrier (BBB) damage, and apoptotic cell death in the ischemic brains and exacerbated neurological outcomes in cerebral ischemia-reperfusion rats at 24 h after MCAO cerebral ischemia. Co-treatment of baicalin significantly reduced the mortality rates, ameliorated the t-PA-mediated BBB disruption and HT. Furthermore, baicalin showed to directly scavenge peroxynitrite and inhibit MMP-9 expression and activity in the ischemic brains with the delayed t-PA treatment. Baicalin had no effect on the t-PA fibrinolytic function indicated by t-PA activity assay. Taken together, baicalin could attenuate t-PA-mediated HT and improve the outcomes of ischemic stroke treatment possibly via inhibiting peroxynitrite-mediated MMP-9 activation.

The Prognostic Value of Serum Uric Acid in the Acute Phase of Ischemic Stroke in Black Africans

BACKGROUND

The association between hyperuricemia and stroke outcome still remains controversial worldwide. This study aims to determine the prevalence of hyperuricemia and its association with the outcome of patients with acute ischemic stroke in a tertiary care hospital.

METHODS

This was a hospital-based prospective cohort study that included patients with ischemic stroke with baseline uric acid levels and 3-month post-stroke follow-up data. Associations between hyperuricemia and stroke outcomes were analyzed using multiple logistic regression, Kaplan-Meier, and Cox proportional hazards regression analysis.

RESULTS

A total of 480 patients were reviewed with a mean age of 62.8 ± 13.3 years. The prevalence of hyperuricemia was 52.3% with mean uricemia of 71.1 ± 25.3 mg/dL. There was a significant association between hyperuricemia and mortality with unadjusted odds ratio (OR) = 4.120 [95% (confidence interval [CI]: 2.466-7.153); P = .001)], but on multivariate analysis, hyperuricemia was not an independent predictor of stroke mortality [OR = 1.270 (CI: .547-2.946); P = .578)]. An independent association between increasing uric acid levels and mortality was noted on Cox proportional hazards regression; adjusted hazard ratio (95% CI) of 3.395 (2.114-5.452), P value greater than .001. Stroke mortality significantly increased across higher uric acid quintiles in patients with acute stroke (P < .001). Hyperuricemia was an independent predictor of poor functional outcome within 3 months after stroke with adjusted OR (95% CI) of 2.820 (1.359-5.851); P = .005.

CONCLUSIONS

Half of black African patients with ischemic stroke present with hyperuricemia, and hyperuricemia is a predictor of mortality and adverse functional outcomes. Further studies are therefore warranted to determine whether reducing hyperuricemia after stroke would be beneficial within our setting.

Association between Serum Uric Acid Level and Activity of Daily Living in Japanese Patients with Ischemic Stroke

BACKGROUND

An association between serum uric acid and outcomes of ischemic stroke has been reported, but the results are controversial. The aim of this study is to clarify how uric acid may affect activities of daily living after acute ischemic stroke.

METHODS

Consecutive Japanese patients with acute ischemic stroke were analyzed. Serum uric acid quartiles and activities of daily living at hospitalization and discharge in men and women were examined. Activities of daily living were evaluated using the modified Rankin scale score, and a score of 3 or higher was defined as poor activities of daily living. P values less than .05 were considered significant.

RESULTS

A total of 987 patients with acute ischemic stroke (591 men; mean age, 72.3 years) were analyzed in this study. We observed a U-shaped relationship between serum uric acid and poor activities of daily living in both men and women at hospitalization and discharge. Multivariate analysis demonstrated that the first quartile group of serum uric acid was significantly associated with poor activities of daily living in both men and women, using the third quartile group as the reference.

CONCLUSIONS

Lower serum uric acid can be a marker for predicting poor activities of daily living in patients with acute ischemic stroke, irrespective of sex.

Relationship between serum uric acid and ischemic stroke in a large type 2 diabetes population in China: A cross-sectional study

OBJECTIVE

To investigate the relationship of serum UA and ischemic stroke in type 2 diabetes patients in China.

METHOD

We examined the above relationship using the data of the project "Comprehensive Research on the Prevention and Control of the Diabetes" (CRPCD) study. A total of 19,442 participants were enrolled in the cross-sectional study. The enrolled participants were divided into quintiles of the serum UA levels with cut off values for two age groups (<60 versus ≥60years). Binary logistic regression analyses were used to evaluate whether the levels of serum UA were independently associated with ischemic stroke in type 2 diabetes.

RESULTS

The serum UA levels were significantly higher in the participants with age≥60years than those with age<60years (P=0.000). In the age group of <60years, the odds ratio for ischemic stroke with type 2 diabetes in quintile 5 over quintile 1 was 2.420 (95% CI, 1.566-3.470) in the unadjusted model and 1.765 (95% CI, 1.097-2.840) after controlling potential confounders. However, the reverse results were observed in the age group of ≥60years. The odds ratio in quintile 4 over quintile 1 in model 3 and model 4 were 0.767 (95% CI, 0.630-0.934) and 0.782 (95% CI, 0.640-0.957).

CONCLUSION

Our results indicated that serum UA levels were independently positively associated with ischemic stroke in patients aged <60years, but the association was U-shaped in patients aged ≥60years.

Neuroprotective effects of adjunctive treatments for acute stroke thrombolysis: a review of clinical evidence

The narrow therapeutic time window and risk of intracranial hemorrhage largely restrict the clinical application of thrombolysis in acute ischemic stroke. Adjunctive treatments added to rt-PA may be beneficial to improve the capacity of neural cell to withstand ischemia, and to reduce the hemorrhage risk as well. This review aims to evaluate the neuroprotective effects of adjunctive treatments in combination with thrombolytic therapy for acute ischemic stroke. Relevant studies were searched in the PubMed, Web of Science and EMBASE database. In this review, we first interpret the potential role of adjunctive treatments to thrombolytic therapy in acute ischemic stroke. Furthermore, we summarize the current clinical evidence for the combination of intravenous recombinant tissue plasminogen activator and various adjunctive therapies in acute ischemic stroke, either pharmacological or non-pharmacological therapy, and discuss the mechanisms of some promising treatments, including uric acid, fingolimod, minocycline, remote ischemic conditioning, hypothermia and transcranial laser therapy. Even though fingolimod, minocycline, hypothermia and remote ischemic conditioning have yielded promising results, they still need to be rigorously investigated in further clinical trials. Further trials should also focus on neuroprotective approach with pleiotropic effects or combined agents with multiple protective mechanisms.

Lower serum uric acid level strongly predict short-term poor functional outcome in acute stroke with normoglycaemia: a cohort study in China

BACKGROUND

Conflicting results on the correlation between hyperuricemia and the prognosis of stroke had been reported and the close association between serum uric acid (SUA) and abnormal glycomatabolism might further complicate the assessment of the correlation. We aimed to investigate SUA in predicting the prognosis of acute stroke in different glycometabolism status.

METHODS

A total of 2907 patients aged from 18 to 85 (1220 diabetes mellitus (DM), 777 prediabetes and 910 normoglycemia) were selected from the Abnormal Glucose Regulation in Patients with Acute Stroke across China (ACROSS-China) study. The patients were divided into groups according to the SUA quartile as well as decile. The correlations between SUA and the poor outcome (mRS > 2) at discharge were assessed stratified by glucose metabolism status. Multivariate logistic regression was used to analyze the potential risk factors of poor in-hospital outcome of stroke and the risk-adjustment of the correlation between SUA and the prognosis of stroke. P < 0.05 was considered statistically significant.

RESULTS

SUA were divided first as Quartile1 to 4 (Quartile1 < 221 μmol L-1; Quartile2 (221-286) μmol L-1; Quartile3 (286-352) μmol L-1 and Quartile4 > 352 μmol L-1), then as decile1 to 10. In normoglycaemia, SUA quartiles, deciles and continuous SUA concentration were independently significantly associated with poor outcome. Q1 was independently associated with the higher possibility of poor functional outcome (compared to Q4, odds ratios (ORs) with 95% confidential interval (CI) was 3.79 (1.23-8.67) in Q1); Lower level of SUA in DM was also associated with poor functional outcome at discharge compared to the highest level of SUA(Q4)(OR with 95% CI, 2.07 (1.05-4.08)), however, lower SUA level was also related to severer stroke at admission in DM as well as in prediabetes (P < 0.001 in DM and 0.023 in prediabetes) and severer stroke resulted in worse functional outcome at discharge (OR with 95% CI, 12.15 (8.08-18.21) in DM and 11.58 (7.50-23.25) in prediabetes). But in normoglycamic stroke, SUA levels did not differ in stroke severity at admission (P = 0.066).

CONCLUSIONS

Low SUA level (<221 μmol L-1) independently and strongly predicts the short-term poor functional outcome in acute stroke with normoglycaemia other than diabetes or prediabetes.

Evaluation of carbon nanotube fiber microelectrodes for neurotransmitter detection: Correlation of electrochemical performance and surface properties

Fibers made of CNTs are attractive microelectrode sensors because they can be directly fabricated into microelectrodes. Different protocols for making CNT fibers have been developed, but differences in surface structure and therefore electrochemical properties that result have not been studied. In this study, we correlated the surface and electrochemical properties for neurochemical detection at 3 types of materials: CNT fibers produced by wet spinning with (1) polyethylenimine (PEI/CNT) or (2) chlorosulfonic acid (CA/CNT), and (3) CNT yarns made by solid-based CNT drawing. CNT yarns had well-aligned, high purity CNTs, abundant oxygen functional groups, and moderate surface roughness which led to the highest dopamine current density (290 ± 65 pA/cm²) and fastest electron transfer kinetics. The crevices of the CNT yarn and PEI/CNT fiber microelectrodes allow dopamine to be momentarily trapped during fast-scan cyclic voltammetry detection, leading to thin-layer cell conditions and a response that was independent of applied waveform frequency. The larger crevices on the PEI/CNT fibers led to a slower time response, showing too much roughness is detrimental to fast detection. CA/CNT fibers have a smoother surface and lower currents, but their negative surface charge results in high selectivity for dopamine over uric acid or ascorbic acid. Overall, small crevices, high conductivity, and abundant oxygen groups led to high sensitivity for amine neurotransmitters, such as dopamine and serotonin. Thus, different surfaces of CNT fibers result in altered electrochemical properties and could be used in the future to predict and control electrochemical performance.

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.

Sex-specific Association Between Uric Acid and Outcomes After Acute Ischemic Stroke: A Prospective Study from CATIS Trial

The relationship between serum uric acid (UA) and outcomes after acute ischemic stroke remains debatable in human studies, and the sex effect on this association has yet to be explored. Here, we investigated these associations in a prospective study from the China Antihypertensive Trial in Acute Ischemic Stroke. Baseline UA levels were measured in 3284 acute ischemic stroke patients. Primary outcome was defined as a combination of death and major disability (modified Rankin Scale score ≥3) at 3 months. UA levels were significantly higher in men than women (310.6 ± 96.1 vs 257.5 ± 89.9 μmol/L, P < 0.001). The association between serum UA and the primary outcome was appreciably modified by sex (P-interaction = 0.007). After multivariate adjustment, a high serum UA was associated with a decreased risk of primary outcome in men [odds ratio (OR), 0.63; 95% confidence interval (CI), 0.44-0.91; P-trend = 0.01] but not in women (OR, 1.29; 95% CI, 0.83-2.01; P-trend = 0.15), when two extreme quartiles were compared. Subgroup and sensitivity analyses further confirmed these sex-specific findings. Our study indicated that there was a sex-specific association between serum UA and prognosis of acute ischemic stroke. Elevated serum UA was positively associated with better prognosis in men, but not in women.