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

Moderate elevation of serum uric acid levels improves short-term functional outcomes of ischemic stroke in patients with type 2 diabetes mellitus

BACKGROUND

Serum uric acid (SUA), an end-product of purine catabolism diffused in the blood, is positively associated with the risk of type 2 diabetes mellitus (T2DM). However, in the T2DM population, the association of SUA fluctuation ([Formula: see text]SUA) with the functional outcome of ischemic stroke (IS) is still unclear. Accordingly, this study aimed to assess the correlation between [Formula: see text]SUA and short-term IS functional outcomes in T2DM patients.

METHODS

All T2DM patients diagnosed with IS in the China National Stroke Registry III were included. [Formula: see text]SUA, which was defined as the difference between the SUA levels at baseline and 3 months after symptom onset, was classified into two groups, i.e., elevated [Formula: see text]SUA ([Formula: see text]SUA > 0) and reduced [Formula: see text]SUA ([Formula: see text]SUA [Formula: see text] 0). The outcomes measured using the Modified Rankin Scale (mRS) were scored from 0 to 6, and poor functional outcome was defined as an mRS score of 3-6 at 3 months after IS.

RESULTS

Among the 1255 participants (mean age: 61.6 ± 9.8 years), 64.9% were men. Patients with elevated [Formula: see text]SUA had a lower incidence of poor functional outcomes at 3 months. Compared with reduced [Formula: see text]SUA, elevated [Formula: see text]SUA at 0-50 μmol/L (odds ratio [OR] = 0.46, 95% confidence interval [CI] = 0.28-0.78, p = 0.004) and 50-100 μmol/L (OR = 0.40, 95% CI = 0.21-0.77, p = 0.006) was significantly correlated with a reduced risk of poor functional outcomes at 3 months.

CONCLUSION

This study showed that a moderate increase in [Formula: see text]SUA in the range of 0-100 μmol/L at 3 months after IS might be beneficial in T2DM adults and more studies are warranted to confirm this.

The Role of Oxidative Stress in Acute Ischemic Stroke-Related Thrombosis

Acute ischemic stroke is a serious life-threatening disease that affects almost 600 million people each year throughout the world with a mortality of more than 10%, while two-thirds of survivors remain disabled. However, the available treatments for ischemic stroke are still limited to thrombolysis and/or mechanical thrombectomy, and there is an urgent need for developing new therapeutic target. Recently, intravascular oxidative stress, derived from endothelial cells, platelets, and leukocytes, has been found to be tightly associated with stroke-related thrombosis. It not only promotes primary thrombus formation by damaging endothelial cells and platelets but also affects thrombus maturation and stability by modifying fibrin components. Thus, oxidative stress is expected to be a novel target for the prevention and treatment of ischemic stroke. In this review, we first discuss the mechanisms by which oxidative stress promotes stroke-related thrombosis, then summarize the oxidative stress biomarkers of stroke-related thrombosis, and finally put forward an antithrombotic therapy targeting oxidative stress in ischemic stroke.

Lower uric acid level may be associated with hemorrhagic transformation after intravenous thrombolysis

BACKGROUND

Previous studies have shown that uric acid (UA) is a powerful water-soluble antioxidant and free radical scavenger for humans. However, the relationship between serum uric acid (SUA) and hemorrhagic transformation (HT) is still controversial. To address this challenge, we aimed to explore the association between serum UA and HT in patients with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT).

METHODS

A retrospective analysis was conducted in patients with anterior circulation AIS who underwent IVT at Affiliated Hospital of Qingdao University from 2016 to 2021. HT was evaluated by CT or MRI within 7 days after admission. Baseline demographic, clinical, and laboratory data were compared between the HT and non-HT groups, and between different types of HT groups which were documented according to the European Cooperative Acute Stroke Study III Classification (ECASS III).

RESULTS

A total of 727 AIS patients were enrolled, including 112 patients who experienced HT (HT group) and 615 patients who did not experience HT (non-HT group). Patients with HT had significantly lower UA levels compared to those without HT (253.65 ± 97.75 vs 315.97 ± 96.42, p < 0.001); however, there was no significant difference for UA levels in different types of HT (p = 0.907). After adjusting confounders, patients in the fourth UA quartile showed a significant decrease in HT compared with those in the first quartile (OR 0.266, 95% CI 0.107-0.661, p = 0.006). The best cutoff value was identified as 218.5 μmol/L after analysis.

CONCLUSIONS

These findings suggest that low levels of UA may be associated with HT after IVT.

Protective Effects of Astragaloside IV on Uric Acid-Induced Pancreatic β-Cell Injury through PI3K/AKT Pathway Activation

Background

Elevated uric acid (UA) has been found to damage pancreatic β-cell, promote oxidative stress, and cause insulin resistance in type 2 diabetes (T2D). Astragaloside IV (AS-IV), a major active monomer extracted from Astragalus membranaceus (Fisch.) Bunge. which belongs to TRIB. Galegeae (Br.) Torrey et Gray, Papilionaceae, exhibits various activities in a pathophysiological environment and has been widely employed to treat diseases. However, the effects of AS-IV on UA-induced pancreatic β-cell damage need to be investigated and the associating mechanism needs to be elucidated. This study was designed to determine the protective effects and underlying mechanism of AS-IV on UA-induced pancreatic β-cell dysfunction in T2D.

Methods

UA-treated Min6 cells were exposed to AS-IV or wortmannin. Thereafter, the 3-(45)-dimethylthiahiazo(-z-y1)-35-di-phenytetrazoliumromide (MTT) assay and flow cytometry were employed to determine the effect of AS-IV on cell proliferation and apoptosis, respectively. Insulin secretion was evaluated using the glucose-stimulated insulin secretion (GSIS) assay. Finally, western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to determine the effect of AS-IV on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway in UA-treated cells.

Results

AS-IV had no cytotoxic effects on Min6 cells. UA significantly suppressed Min6 cell growth, promoted cell apoptosis, and enhanced caspase-3 activity; however, AS-IV abolished these effects in a dose-dependent manner. Further, decreased insulin secretion was found in UA-treated Min6 cells compared to control cells, and the production of insulin was enhanced by AS-IV in a dose-dependent manner. AS-IV significantly increased phosphorylated (p)-AKT expression and the ratio of p-AKT/AKT in Min6 cells exposed to UA. No evident change in AKT mRNA level was found in the different groups. However, the effects of AS-IV on UA-stimulated Min6 cells were reversed by 100 nM wortmannin.

Conclusion

Collectively, our data suggest that AS-IV protected pancreatic β-cells from UA-treated dysfunction by activating the PI3K/AKT pathway. Such findings suggest that AS-IV may be an efficient natural agent against T2D.

Serum Uric Acid Levels and Their Changes and Risk of Stroke: A 7-Year Prospective Cohort Study in Northwest China

INTRODUCTION

It is not clear whether serum uric acid (SUA) levels and their changes over time are associated with the risk of stroke. A 7-year prospective cohort study in northwest China was conducted to analyze effects of SUA and their changes on the risk of stroke.

METHODS

A total of 23,262 individuals without cardiovascular disease in the Jinchang cohort were followed up for an average of 5.26 years. The Cox proportional hazard model was used to estimate the hazard ratios (HRs) and 95% confidence interval (95% CI) of stroke incidence to SUA and relative changes in SUA. Sensitivity analysis was performed after controlling the effect of renal insufficiency.

RESULTS

Baseline SUA and relative changes in SUA were positively correlated with the incidence of stroke in both males and females (p for overall association <0.0001). Stroke risk increased by 4.6% per 10% increase in the relative change of SUA (HR = 1.046, 95% CI, 1.007-1.086). The fully adjusted regression analysis demonstrated that only the large gain (>30%) in SUA was associated with an increased risk of stroke by 36.5% (95% CI, 1.8-83.0%), compared with the reference group (participants within ±10% changes in SUA). The same trend was observed in people with normal baseline SUA. In the unadjusted model, the risk of stroke associated with elevated SUA was significantly higher in the hyperuricemia group than in the normal SUA group.

CONCLUSION

High initial SUA concentration and an increase in SUA concentration over time would increase the risk of stroke, and this means that there is no safe increase in SUA.

Serum Uric Acid and Diabetes: From Pathophysiology to Cardiovascular Disease

Hyperuricemia, has been traditionally related to nephrolithiasis and gout. However, it has also been associated with the development of type 2 diabetes mellitus (T2DM) and cardiometabolic and cardiovascular diseases. Pathophysiologically, elevated serum uric acid (SUA) levels may be associated with abnormal lipid and glucose metabolism. In this narrative review, we consider the associations between hyperuricemia, hyperglycemia, atherosclerosis and thrombosis. Furthermore, we comment on the available evidence linking elevated SUA levels with the incidence and outcomes of coronary heart disease, stroke, peripheral artery disease and non-alcoholic fatty liver in subjects with T2DM. The effects of antidiabetic drugs (e.g. metformin, pioglitazone, sulfonylureas, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors and insulin) on SUA concentrations are also reviewed.

Combined effect of hypertension and hyperuricemia on ischemic stroke in a rural Chinese population

Background

To investigate the combined effect of hypertension and hyperuricemia to the risk of ischemic stroke in a rural Chinese population.

Methods

The cross-sectional study was conducted from 2012 to 2013 in a rural area of China. After exclusion for missing data, we finally included 11,731 participants into analysis.

Results

After adjusting for age, current smoking, current drinking, BMI, TG, HDL-C and eGFR, hypertension was significantly associated with ischemic stroke in men (OR: 2.783, 95% CI: 1.793, 4.320) and in women (OR: 4.800, 95% CI: 2.945, 7.822). However, hyperuricemia was significantly associated with ischemic stroke only in women (OR: 1.888, 95% CI: 1.244, 2.864). After full adjustment, participants with both hypertension and hyperuricemia had 8.9 times higher risk than those without them. Finally, the interaction between hypertension and hyperuricemia was statistically significant only in women rather than in men after full adjustment.

Conclusions

This study demonstrated the positive correlations between hypertension, hyperuricemia and ischemic stroke. Our study also demonstrated the joint effect between hypertension and hyperuricemia towards ischemic stroke only in women, not in men.

Gut microbiota-derived propionate mediates the neuroprotective effect of osteocalcin in a mouse model of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder with no absolute cure. The evidence of the involvement of gut microbiota in PD pathogenesis suggests the need to identify certain molecule(s) derived from the gut microbiota, which has the potential to manage PD. Osteocalcin (OCN), an osteoblast-secreted protein, has been shown to modulate brain function. Thus, it is of interest to investigate whether OCN could exert protective effect on PD and, if yes, whether the underlying mechanism lies in the subsequent changes in gut microbiota.

RESULTS

The intraperitoneal injection of OCN can effectively ameliorate the motor deficits and dopaminergic neuronal loss in a 6-hydroxydopamine-induced PD mouse model. The further antibiotics treatment and fecal microbiota transplantation experiments confirmed that the gut microbiota was required for OCN-induced protection in PD mice. OCN elevated Bacteroidetes and depleted Firmicutes phyla in the gut microbiota of PD mice with elevated potential of microbial propionate production and was confirmed by fecal propionate levels. Two months of orally administered propionate successfully rescued motor deficits and dopaminergic neuronal loss in PD mice. Furthermore, AR420626, the agonist of FFAR3, which is the receptor of propionate, mimicked the neuroprotective effects of propionate and the ablation of enteric neurons blocked the prevention of dopaminergic neuronal loss by propionate in PD mice.

CONCLUSIONS

Together, our results demonstrate that OCN ameliorates motor deficits and dopaminergic neuronal loss in PD mice, modulating gut microbiome and increasing propionate level might be an underlying mechanism responsible for the neuroprotective effects of OCN on PD, and the FFAR3, expressed in enteric nervous system, might be the main action site of propionate. Video abstract.

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.

J-shaped relationship between serum uric acid levels and the risk of ischemic stroke in high-risk individuals: A hospital-based observational study

OBJECTIVE

The relationship between serum uric acid (SUA) and the risk of ischemic stroke (IS) has been fully elucidated in previous studies. Therefore, we further investigated the relationship between SUA levels and the risk of IS.

PATIENTS AND METHODS

2195 patients at the Beijing Hospital, between February 2012 and May 2018, were enrolled in our hospital-based cross-sectional study. The patients were divided into an IS group and a (non-IS) control group, based on their medical records. SUA level was measured using the enzymatic uricase method. Univariate and multivariable logistic regression models were used for the analysis.

RESULTS

A total of 300 patients with IS [176 men; age (mean ± SD): 71.38 ± 10.66 years] and 1895 control patients [1060 men; age (mean ± SD): 66.12 ± 12.04 years] were enrolled in this study. IS patients had higher concentrations of SUA, compared with control group patients [6.11 ± 1.92 vs. 5.77 ± 1.62 (mg/dL)]; P = 0.004). We observed a J-shaped association between SUA levels and the risk of IS. Both the univariate and multivariate logistic regression analyses found a significantly elevated risk of IS in the bottom and upper SUA levels both in quartiles and deciles, compared with the intermediate SUA levels.

CONCLUSION

These results indicate a J-shaped, independent association between SUA levels and the risk of IS in high-risk individuals.

The association between serum uric acid levels and ischemic stroke in essential hypertension patients

Objectives: The association between serum uric acid (SUA) and ischemic stroke is still inconsistent across population. This study aimed to examine the association between SUA and ischemic stroke in essential hypertension patients. Methods: This retrospective study recruited participants from September 2011 to December 2012, in the Liao-bu community, Guangdong Province, China, and followed them until 31 December 2016. Participants were divided into quartiles based on SUA concentrations. Hazard ratio (HR) and confidence intervals (CIs) was estimated from Cox proportional hazards models, and propensity score analysis, Kaplan-Meier survival curves and receiver operating characteristic (ROC) curve were performed to evaluate the relationship between SUA and the risk of ischemic stroke. Results: A total of 5473 eligible hypertensive subjects were enrolled in this study, 2666 (48.71%) of them were males with an average age of 62.02 ± 13.76 years. A total of 155 (2.83%) ischemic stroke occurred after the mean follow-up period of 4.5 years. After adjusting for potential confounders, comparing with the lowest quartiles of SUA, multivariable HR (95%CI) for ischemic stroke for participants with SUA at the second, third and fourth quartiles were 1.13 (95%CI: 1.10, 1.81), 1.39 (95%CI: 1.18, 1.89), and 1.64 (95%CI: 1.19, 1.95), respectively (P < 0.0001 for trend). Elevated SUA was positively associated with ischemic stroke (HR = 1.41, 95%CI: 1.16, 1.84; P < 0.01) and the propensity scores analysis (HR = 1.45, 95%CI: 1.17, 1.90; P < 0.01) showed the similar results. Gender subgroup analysis showed SUA was an independent risk of ischemic stroke in female (HR = 1.35, 95%CI: 1.11, 1.81, P = 0.002) and male (HR = 1.53, 95%CI: 1.14, 1.92, P < 0.001). ROC curve demonstrated that SUA yielded an AUC of 0.7476 (95%CI: 0.7098, 0.7855, P < 0.001) for predictive of ischemic stroke. Conclusions: SUA was an independent risk factor for ischemic stroke, and also have a good predictive value ischemic stroke among hypertensive patients in Chinese community.

Effects of Uric Acid on Diabetes Mellitus and Its Chronic Complications

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

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.

Correlation between serum uric acid and diabetic peripheral neuropathy in T2DM patients

AIM

To investigate the correlation between serum uric acid (SUA) and diabetic peripheral neuropathy (DPN) in type 2 diabetes mellitus (T2DM) patients.

METHODS

Two hundred T2DM patients were divided into four groups at the cut-off points of 5, 7, and 9mg/dL of SUA levels. Nerve conduction studies (NCS), Semmes-Weinstein monofilament testing (SWMT), and vibration perception threshold (VPT) tests were performed on these patients.

RESULTS

Significant differences in motor/sensory nerve amplitude and conduction velocity (CV) parameters among different SUA level groups were observed (all P<0.05). SUA levels were negatively correlated with the means of motor/sensory nerve amplitude and CV (all P<0.05). Duration of T2DM >10years, SUA >9mg/dL and total cholesterol (TC) >5.2mmol/L were found to be significantly associated with DPN (all P<0.05). Receiver-operating characteristic (ROC) analysis revealed that the cut-off points of T2DM duration combined with SUA and TC were 9years, 7.8mg/dL, and 4.97mmol/L, respectively (AUC=0.65; 95% CI: 0.53-0.77; sensitivity, 70.6%; specificity, 65.2%, P=0.009).

CONCLUSION

There is a significant association between elevated SUA levels and DPN, and T2DM duration, SUA, and TC may be valuable indicators to predict the occurrence of DPN in T2DM patients.