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

Low Serum Uric Acid Levels are Associated with Severe Diabetic Foot Infection: A Cross-Sectional Study from China

Diabetic foot ulcers (DFUs) are among the most serious complications of diabetes which are associated with high disability and mortality rates. This study aims to investigate the associations between uric acid (UA) levels and diabetic foot ulcer (DFU) characteristics. In total, 1820 participants with DFUs were included in this study; 192 and 1628 participants were included in the hyperuricemia group (HUA, UA > 420 µmol/L) and the nonhyperuricemia group (NHUA, UA ≤420 µmol/L), respectively. The NHUA group was divided into a middle-UA subgroup (SMUA, 420 µmol/L ≥ UA ≥ 180 µmol/L; 304 individuals) and a low-UA subgroup (SLUA, UA <180 µmol/L; 1324 individuals). There were no significant differences in the rates of deep ulcers, severe infection or amputation between NHUA and HUA. In univariate analysis of subgroups, the differences in the rates of deep ulcers, severe infection and amputation were significant. After adjusting for confounders (sex, fasting glucose level, diabetes duration, eGFR, deep ulcers and severe infection) in multivariate analysis, the severe infection rate (OR = 4.0, 95%CI 1.6-10.0, P < 0.01) was still significantly greater in the SLUA group than in the SMUA group while the rate of deep ulcers (OR =2.4, 95%CI 1.0-6.1, P = 0.06) and amputation (OR =1.1, 95%CI 0.3-4.3, P = 0.91) showed non-statistical difference. UA levels below 180 µmol/L can be a risk factor for severe infection in DFUs.

A Novel Nomogram Integrating Retinal Microvasculature and Clinical Indicators for Individualized Prediction of Early Neurological Deterioration in Single Subcortical Infarction

AIMS

Early neurological deterioration (END) is a relatively common occurrence among patients with single subcortical infarctions (SSI). Accurate and early prediction of END in SSI is challenging and could contribute to enhancing prognosis.

METHODS

This prospective observational study enrolled SSI patients who arrived within 24 h from symptom onset at a single center between December 2020 and March 2023. The least absolute shrinkage and selection operator (LASSO) regression model was applied to optimize feature selection for the predictive model. A nomogram was generated based on multivariate logistic regression analysis to identify potential predictors associated with the risk of END. The performance and clinical utility of the nomogram were generated using Harrell's concordance index, calibration curve, and decision curve analysis (DCA).

RESULTS

Of 166 acute SSI patients, 45 patients (27.1%) developed END after admission. The appearance of END is associated with four routine clinical factors (NIHSS score, serum neuron-specific enolase, uric acid, periventricular white matter hyperintensity), and two retinal microvascular indicators (ipsilateral superficial and deep vascular complexes). Incorporating these factors, the nomogram model achieved a concordance index of 0.922 (95% CI 0.879-0.964) and had a well-fitted calibration curve and good clinical application value by DCA. A cutoff value of 203 was determined to predict END via this nomogram.

CONCLUSIONS

This novel nomogram exhibits high accuracy in predicting END in SSI patients. It could guide clinicians to identify SSI patients with a high risk of END at an early stage and initiate necessary medical interventions, ultimately leading to a better prognosis.

A New Perspective on the Prediction and Treatment of Stroke: The Role of Uric Acid

Stroke, a major cerebrovascular disease, has high morbidity and mortality. Effective methods to reduce the risk and improve the prognosis are lacking. Currently, uric acid (UA) is associated with the pathological mechanism, prognosis, and therapy of stroke. UA plays pro/anti-oxidative and pro-inflammatory roles in vivo. The specific role of UA in stroke, which may have both neuroprotective and damaging effects, remains unclear. There is a U-shaped association between serum uric acid (SUA) levels and ischemic stroke (IS). UA therapy provides neuroprotection during reperfusion therapy for acute ischemic stroke (AIS). Urate-lowering therapy (ULT) plays a protective role in IS with hyperuricemia or gout. SUA levels are associated with the cerebrovascular injury mechanism, risk, and outcomes of hemorrhagic stroke. In this review, we summarize the current research on the role of UA in stroke, providing potential targets for its prediction and treatment.

Serum uric acid/creatinine ratio and 1-year stroke recurrence in patient with acute ischemic stroke and abnormal renal function: results from the Xi'an stroke registry study of China

Background

The relationship between abnormal renal function and serum uric acid levels in patients with acute ischemic stroke (AIS) remains insufficiently explored. Although uric acid is associated with cardiovascular and cerebrovascular risk, the specific link between normalized serum uric acid (SUA/SCr) and stroke recurrence in patients with impaired renal function has not been well studied. This study aims to fill this gap by investigating the association between SUA/SCr and 1-year stroke recurrence in patients with AIS and abnormal renal function.

Methods

This study utilized the ratio of serum uric acid (SUA) to serum creatinine (SCr) to represent SUA levels normalized for renal function. Abnormal Renal function was defined by the estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m2. Multivariable Cox regression, curve fitting, and stratified analyses were employed to assess the relationship between SUA/SCr and 1-year stroke recurrence in patients with AIS and abnormal renal function, considering SUA/SCr as both a continuous variable and in quartiles (Q1-Q4).

Results

Of 1,932 enrolled patients (65.3% male; mean age 66.7 ± 11.3 years), each unit of increase in SUA/SCr was associated with a 17% decrease in 1-year stroke recurrence (HR = 0.83, 95% CI 0.73 to 0.96, P = 0.009). Compared to Q1, the Q2 and Q4 groups showed significantly reduced risk in 1-year stroke recurrence (Q2: HR = 0.46, 95% CI 0.27 to 0.79, P = 0.005; Q4: HR = 0.47, 95% CI 0.27 to 0.81, P = 0.007), with a significant trend across all quartiles (P = 0.01 for trend tests). Curve fitting revealed a negative but non-linear correlation. Subgroup analyses showed that in patients with eGFR < 60 ml/min/1.73 m2, Q4 had significantly lower 1-year stroke recurrence risk than Q1 (HR = 0.19, 95% CI 0.04 to 0.86, P = 0.031).

Conclusion

Low SUA/SCr independently predicts 1-year stroke recurrence in patients with AIS and abnormal renal function, particularly in those with eGFR < 60 mL/min/1.73 m2.

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.

Predictive models for secondary epilepsy in patients with acute ischemic stroke within one year

Background

Post-stroke epilepsy (PSE) is a critical complication that worsens both prognosis and quality of life in patients with ischemic stroke. An interpretable machine learning model was developed to predict PSE using medical records from four hospitals in Chongqing.

Methods

Medical records, imaging reports, and laboratory test results from 21,459 ischemic stroke patients were collected and analyzed. Univariable and multivariable statistical analyses identified key predictive factors. The dataset was split into a 70% training set and a 30% testing set. To address the class imbalance, the Synthetic Minority Oversampling Technique combined with Edited Nearest Neighbors was employed. Nine widely used machine learning algorithms were evaluated using relevant prediction metrics, with SHAP (SHapley Additive exPlanations) used to interpret the model and assess the contributions of different features.

Results

Regression analyses revealed that complications such as hydrocephalus, cerebral hernia, and deep vein thrombosis, as well as specific brain regions (frontal, parietal, and temporal lobes), significantly contributed to PSE. Factors such as age, gender, NIH Stroke Scale (NIHSS) scores, and laboratory results like WBC count and D-dimer levels were associated with increased PSE risk. Tree-based methods like Random Forest, XGBoost, and LightGBM showed strong predictive performance, achieving an AUC of 0.99.

Conclusions

The model accurately predicts PSE risk, with tree-based models demonstrating superior performance. NIHSS score, WBC count, and D-dimer were identified as the most crucial predictors.

Funding

The research is funded by Central University basic research young teachers and students research ability promotion sub-projec t(2023CDJYGRH-ZD06), and by Emergency Medicine Chongqing Key Laboratory Talent Innovation and development joint fund project (2024RCCX10).

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.

Baseline Uric Acid Levels and Intravenous Thrombolysis Outcomes in Patients With Acute Ischemic Stroke: A Prospective Cohort Study

BACKGROUND

The study aimed to investigate the relationship between uric acid (UA) levels and functional outcomes at 3 months in patients with acute ischemic stroke (AIS) who underwent intravenous thrombolysis (IVT).

METHODS AND RESULTS

This prospective cohort study included 1001 consecutive patients with AIS who underwent IVT. The correlation between UA levels and post-IVT AIS outcomes was examined. Any nonlinear relationship was assessed using a restricted cubic spline function. The nonlinear P value for the association of UA levels with favorable (modified Rankin Scale [mRS] score ≤2) and excellent (mRS score ≤1) outcomes at 3 months post-IVT were <0.001 and 0.001, respectively. However, for patients with and without hyperuricemia, no evident nonlinear relationship was observed between UA levels and favorable 3-month post-IVT outcomes, with nonlinear P values of 0.299 and 0.207, respectively. The corresponding interaction analysis yielded a P value of 0.001, indicating significant heterogeneity. Similar results were obtained for excellent outcomes at 3 months post-IVT. In the hyperuricemia group, increased UA levels by 50 μmol/L reduced the odds of a favorable 3-month post-AIS outcome (odds ratio [OR], 0.75 [95% CI, 0.57-0.97]). Conversely, in the nonhyperuricemia group, a similar UA increase was linked to higher favorable outcome odds (OR, 1.31 [95% CI, 1.15-1.50]).

CONCLUSIONS

An inverted U-shaped nonlinear relationship was observed between UA levels and favorable and excellent outcomes at 3 months in patients with AIS who underwent IVT. Higher UA levels predict favorable outcomes in patients without hyperuricemia but unfavorable outcomes in those with hyperuricemia.

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.

Serum uric acid and prognosis in acute ischemic stroke: a dose-response meta-analysis of cohort studies

Background

There have been contradictory findings regarding the relationship between serum uric acid levels and prognosis in acute ischemic stroke. Whether this association is nonlinear due to uric acid's paradoxical properties (antioxidant and prooxidant) is unclear.

Methods

We searched PubMed, Web of Science, and Embase databases until December 2022. Cohort studies reporting serum uric acid levels and functional outcome, mortality, or neurological complications in patients with acute ischemic stroke were included. Summary effect estimates were calculated using a random-effect model. Moreover, dose-response relationships were assessed by the generalized least squares trend estimation.

Results

Altogether, 13 cohort studies were identified in this study. Compared to the lowest baseline serum uric acid levels, the highest levels were associated with decreased risk of poor functional outcome (OR = 0.70, 95% CI 0.54-0.91, I2 = 29%), hemorrhagic transformation (OR = 0.15, 95% CI 0.05-0.42, I2 = 79%), and post-stroke depression (OR = 0.04, 95% CI 0.00-0.95, I2 = 89%), but not associated with mortality and symptomatic intracerebral hemorrhage. A nonlinear relationship was observed in poor functional outcome (U-shaped, P for nonlinearity = 0.042), hemorrhagic transformation (inverse, P for nonlinearity = 0.001), and post-stroke depression (inverse, P for nonlinearity = 0.002). In addition, there was a single study reporting a U-shaped association in post-stroke epilepsy (P for nonlinearity <0.001). Furthermore, another study reported a positive curvilinear association in stroke recurrence (P for nonlinearity <0.05). The insufficient number of original articles for some prognostic indicators should be considered when interpreting the results of this meta-analysis.

Conclusion

In patients with acute ischemic stroke, serum uric acid levels are nonlinearly associated with the risk of poor functional outcome (U-shaped). More evidence is needed to confirm the association between serum uric acid levels and neurological complications following acute ischemic stroke.

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.

U-Shaped Association Between Serum Uric Acid and Hemorrhagic Transformation After Intravenous Thrombolysis

BACKGROUND

Uric acid (UA) has both antioxidative and pro-oxidative properties. The study aimed to investigate the relationship between serum UA and hemorrhagic transformation (HT) after intravenous thrombolysis in patients with acute ischemic stroke.

METHODS

The patients undergoing intravenous thrombolysis from two hospitals in China were retrospectively analyzed. HT was evaluated using computed tomography images reviewed within 24- 36h after thrombolysis. Symptomatic intracranial hemorrhage (sICH) was defined as HT accompanied by worsening neurological function. Multivariate logistic regression and spline regression models were performed to explore the relationship between serum UA levels and the risk of HT and sICH.

RESULTS

Among 503 included patients, 60 (11.9%) were diagnosed with HT and 22 (4.4%) developed sICH. Patients with HT had significant lower serum UA levels than those without HT (245 [214-325 vs. 312 [256-370] μmol/L, p < 0.001). Multivariable logistic regression analysis indicated that patients with higher serum UA levels had a lower risk of HT (OR per 10-μmol/L increase 0.96, 95%CI 0.92-0.99, p = 0.015). Furthermore, multiple-adjusted spline regression models showed a Ushaped association between serum UA levels and HT (p < 0.001 for non-linearity). Similar results were present between serum UA and sICH. Restricted cubic spline models predicted the lowest risk of HT and sICH when the serum UA levels were 386μmol/L.

CONCLUSION

The data show the U-shaped relationship between serum UA levels and the risk of HT and sICH after intravenous thrombolysis.

Uric Acid and Clinical Outcomes in Young Patients with Ischemic Stroke

BACKGROUND AND PURPOSE

There is limited available evidence for the relationship between uric acid (UA) levels and ischemic stroke in young adults. We aimed to explore the association between UA levels and acute ischemic stroke (AIS) in young patients.

MATERIALS AND METHODS

This was a prospective and observational study. We recruited young patients aged 18-45 years with AIS at our tertiary hospital. Patients were categorized into four groups according to quartiles of UA levels. The primary outcome was functional outcome at 3 months. The secondary outcomes included stroke severity, in-hospital complications, and functional outcome at discharge. Modified Rankin Scale (mRS) scores were used to assess functional outcome as poor (mRS=2-6) or favorable(mRS=0-1).

RESULTS

A total of 636 patients were enrolled in the current analysis. The four groups were defined as follows: Q1≤289.8 µmol/L, 289.8 µmol/ L<Q2≤349.0 µmol/L, 349.0 µmol/L<Q3≤421 µmol/L, and Q4>421 µmol/L. Multiple logistic regression analysis showed that UA levels were not significantly predictive of functional outcome either at discharge or at 3 months after AIS. However, compared to Q1, higher UA levels were significantly negatively associated with the rate of moderate-severe stroke (NIHSS≥5) at admission (p for trend =0.016). Furthermore, a reduction in the risk for in-hospital pneumonia was significantly associated with higher UA levels compared to Q1 (P for trend < 0.0001).

CONCLUSION

Serum UA was a protective factor for stroke severity and in-hospital pneumonia after AIS in young patients. However, we were unable to identify the predictive significance of UA for functional outcome either at discharge or at 3 months after AIS.

Sex-specific relationship between serum uric acid levels and the prevalence of large vessel occlusion in acute ischemic stroke

PURPOSE

Previous studies have found that uric acid (UA) plays a neuroprotective role in ischemic stroke patients. However, the relationship between serum UA of acute ischemic stroke (AIS) and large vessel occlusion (LVO) strokes is unclear.

METHODS

In this retrospective study, 1318 AIS patients were enrolled. All patients underwent imaging examinations to assess the intracranial and carotid vessels. Multivariate logistic regression analysis was conducted to evaluate the relationship between UA levels and the prevalence of LVO.

RESULTS

The 1318 enrolled AIS patients were comprised of 287 LVO and 1031 non-LVO patients. UA levels in males were higher than females (321.04 ± 91.28 vs. 274.43 ± 82.11, p < .001). The association between serum UA levels and LVO was modified by sex (p = .007). When serum UA levels were continuous, after adjusting for related risk factors, higher serum UA levels were still associated with a lower prevalence of LVO in males (odds ratio (OR) 0.997, 95% confidence interval (CI) 0.994-0.999), but not in female subjects (OR 0.998, 95% CI 0.995-1.001). When serum UA levels were divided into tertiles, higher UA levels had a lower risk of LVO than the moderate (p = .006) and lower tertiles of UA levels (p = .010) in males, but not in females (p = .402 and p = .206 for moderate and low tertiles, respectively).

CONCLUSIONS

AIS patients with higher serum UA levels tend to be associated with a lower risk of LVO in males, but not in females.