Serum uric acid and risk of stroke and its types: the Circulatory Risk in Communities Study (CIRCS)

Genetically predicted type 2 diabetes mellitus mediates the causal association between plasma uric acid and ischemic stroke

OBJECTIVE

This study conducts a systematic investigation into the causal relationships between plasma uric acid levels and subtypes of ischemic stroke (IS), as well as the extent to which Type 2 diabetes mellitus (T2DM) mediates this relationship.

BACKGROUND

There is a known association between Uric acid and IS but whether they have a causal relationship remains unclear. This study aims to determine whether a genetic predisposition to uric acid is causally linked to IS, including three subtypes, and to determine the mediating role of T2DM.

METHODS

Bidirectional Mendelian randomization (MR) analyses was initially used to explore the causal relationship between uric acid and three subtypes of IS. Two-step MR methods were then used to investigate the role of T2DM in mediating the effect of uric acid and IS with its subtypes.

RESULTS

A primary analysis showed uric acid had a markedly causal association with IS (IVW, OR 1.23; 95 % CI, 1.13 - 1.34; p = 6.39 × 10-9), and two subtypes of IS, Large-vessel atherosclerotic stroke LAS (IVW, OR 1.25; 95 % CI, 1.03 - 1.53; p = 0.026) and small vessel stroke (SVS) (IVW, OR 1.20; 95 % CI, 1.00 - 1.43; p = 0.049), but not with cardioembolic stroke (CES)(IVW, OR 1.00; 95 % CI, 0.87 - 1.15; p = 0.993). Two-step MR results showed that T2DM mediated the association between uric acid and LAS and SVS, accounting for 13.85 % (p = 0.025) and 13.57 % (p = 0.028), respectively.

CONCLUSIONS

The study suggests that genetic predisposition to uric acid is linked to a greater risk of IS, especially LAS and SVS. T2DM might mediate a significant proportion of the associations between uric acid and LAS as well as SVS.

Higher Atherogenic Index of Plasma Is Associated with Hyperuricemia: A National Longitudinal Study

Background

The association between atherogenic index of plasma (AIP) and hyperuricemia remains indistinct. This study was aimed to examine the relationship between AIP and hyperuricemia among the middle-aged and the elderly Chinese population.

Methods

Datasets were retrieved from the China Health and Retirement Longitudinal Study (CHARLS) survey conducted in 2011 and 2015. 13,021 participants in the CHARLS in 2011 and 7,017 participants involved both in 2011 and 2015 were included, respectively. The measurement of AIP and hyperuricemia was based on the test of fasting blood. Association between AIP and hyperuricemia was assessed by logistic regression, and the nonlinear association was examined by restricted cubic splines (RCS). The cutoff point of AIP was calculated using receiver operator curve (ROC). 1 : 1 propensity score matching (PSM) was adopted to further explore the relationship between AIP and hyperuricemia.

Results

In the section of a cross-sectional study, a positive association between AIP and hyperuricemia was found. The odds ratios (ORs) of hyperuricemia were 1.00 (reference), 1.52 (1.10-2.10), 1.80 (1.31-2.47), and 3.81 (2.84-5.11). Nonlinear association was not detected using RCS analysis. There were 664 hyperuricemia cases during the four years follow-up. The hyperuricemia prevalence was 9.5%. In the fully adjusted longitudinal analysis, the ORs for hyperuricemia across the quartiles of AIP were 1.00 (reference), 1.00 (0.74-1.37), 1.59 (1.20-2.11), and 2.55 (1.94-3.35), respectively. In the longitudinal analysis after PSM, the OR of hyperuricemia were 1.91 (1.45, 2.51) and 1.92 (1.45, 2.54) in the univariate and multivariate model, respectively.

Conclusion

AIP can predict the prevalence of hyperuricemia in the Chinese middle-aged and elderly population.

Exploring the Multifaceted Nexus of Uric Acid and Health: A Review of Recent Studies on Diverse Diseases

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.

Risk Factors for Hyperuricemia or Gout in Men and Women: The Circulatory Risk in Communities Study (CIRCS)

AIM

We aimed to examine sex-specific risk factors for hyperuricemia or gout in Japanese cohorts.

METHODS

We followed up 3,188 men (mean age, 55.6 years) and 6,346 women (mean age, 54.1 years) without hyperuricemia, gout, or elevated liver enzymes at baseline from 1986 to 1990 for a median of 14.6 years. The participants were considered as having hyperuricemia or gout if their serum uric acid levels were ≥ 7.0 mg/dL or they were receiving treatment for hyperuricemia or gout during annual health checkups. The sex-specific multivariable hazard ratios (HRs) of hyperuricemia or gout incidence were calculated after adjustment for smoking and drinking status, body mass index, hypertension, diabetes, hypercholesterolemia, and hypertriglyceridemia using the Cox proportional-hazard model.

RESULTS

During follow-up, 733 men and 355 women had hyperuricemia or gout. Among men, the multivariable HRs (95% confidence intervals) of hyperuricemia or gout were 1.23 (1.00-1.52) and 1.41 (1.13-1.75) for drinkers of ＜46 and ≥ 46 g ethanol/day, respectively, compared with non-drinkers; 1.00 (0.81-1.24) and 1.18 (0.93-1.50) for smokers of 1-19 and ≥ 20 cigarettes/day, respectively, compared with never smokers; and 1.41 (1.20-1.65) for hypertensive compared with non-hypertensive participants. The HRs for women were 1.02 (0.70-1.48), 1.66 (1.05-2.63), and 1.12 (0.88-1.42) for current drinkers, current smokers, and hypertensive participants, respectively. For both men and women, body mass index, diabetes, hypercholesterolemia, and hypertriglyceridemia were not associated with hyperuricemia or gout incidence.

CONCLUSIONS

Hypertension and alcohol drinking are risk factors for hyperuricemia or gout among men and smoking among women.

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.

Uric acid and neurological disease: a narrative review

Hyperuricemia often accompanies hypertension, diabetes, dyslipidemia, metabolic syndrome, and chronic renal disease; it is also closely related to cardiovascular disease. Moreover, several epidemiological studies have linked hyperuricemia and ischemic stroke. However, uric acid may also have neuroprotective effects because of its antioxidant properties. An association between low uric acid levels and neurodegenerative diseases has been suggested, which may be attributed to diminished neuroprotective effects as a result of reduced uric acid. This review will focus on the relationship between uric acid and various neurological diseases including stroke, neuroimmune diseases, and neurodegenerative diseases. When considering both the risk and pathogenesis of neurological diseases, it is important to consider the conflicting dual nature of uric acid as both a vascular risk factor and a neuroprotective factor. This dual nature of uric acid is important because it may help to elucidate the biological role of uric acid in various neurological diseases and provide new insights into the etiology and treatment of these diseases.

Association of serum uric acid to lymphocyte ratio, a novel inflammatory biomarker, with risk of stroke: A prospective cohort study

MAIN PROBLEM

Inflammation plays an important role in the pathological progress associated with stroke. Serum uric acid (SUA) to lymphocyte ratio (ULR), a novel inflammatory biomarker, has been considered as a better risk stratification tool of adverse outcomes than SUA or lymphocyte alone. This study aimed to investigate whether ULR produced more predictive value for stroke and explore the potential mediators of the associations.

METHODS

This study enrolled 93,023 Chinese participants without stroke and myocardial infarction at baseline. Cox proportional hazard models were used to analyze the associations of ULR with stroke and subtypes. Mediation analyses were conducted to explore potential mediators of the associations.

RESULTS

During a median follow-up of 13.00 years, 6081 cases of incident stroke occurred, including 5048 cases of ischemic stroke (IS) and 900 cases of hemorrhagic stroke (HS). After adjustment for confounders, the Q4 group was associated with a higher risk of HS (HR, 1.25; 95% CI, 1.03-1.50), but not with total stroke (HR, 1.07; 95% CI, 1.03-1.13) or IS (HR, 1.04; 95% CI, 0.97-1.12). No significant associations were found between SUA or lymphocyte and any stroke. ULR outperformed SUA or lymphocytes alone in predicting stroke. Additionally, the significant association between ULR and HS was partially mediated by systolic blood pressure (20.32%), diastolic blood pressure (11.18%) and estimated glomerular filtration rate (9.19%).

CONCLUSIONS

ULR was significantly associated with the risk of HS, but not with IS. Systolic blood pressure, diastolic blood pressure and estimated glomerular filtration rate were potential mediators for the association.

Serum uric acid levels and the risk of diabetes mellitus in premenopausal and postmenopausal women: the Suita study

OBJECTIVE

The association between serum uric acid levels and the risk of diabetes mellitus in women stratified by menopausal status is not well-established. Therefore, we investigated this association among a cohort of Japanese urban women.

METHODS

We conducted a prospective cohort study on 3,304 women (1,252 premenopausal and 2,052 postmenopausal), aged 30 to 79 years, with no prior cardiovascular disease or diabetes mellitus, and enrolled from a general urban population. Cox proportional hazard model was used to calculate hazard ratios and 95% confidence intervals (CIs) for incident diabetes mellitus according to serum uric acid quartiles.

RESULTS

During 13.8 years of median follow-up, 219 incident diabetes mellitus cases were diagnosed. The incidence rate per 1,000 person-years was 3.42 in premenopausal women and 6.19 in postmenopausal women. After adjustment for potential risk factors, the multivariable hazard ratios (95% CIs) of the highest versus lowest serum uric acid quartiles were 1.56 (0.77-3.16) in premenopausal women, 2.00 (1.19-3.34) in postmenopausal women, and 1.81 (1.21-2.73) in all women. The interaction based on menopausal status was not significant ( P = 0.872). The corresponding population attributable fractions (95% CIs) were 13.3% (-8.9% to 31.1%), 19.1% (5.3%-30.9%), and 17.0% (5.6%-27.0%), respectively.

CONCLUSIONS

Serum uric acid levels were positively associated with the risk of diabetes mellitus in postmenopausal women, but not in premenopausal women. However, the lack of an association in premenopausal women may have been due to limited power, so further research is required to confirm this menopausal status-specific association.

The Impact of an Elevated Uric Acid Level on the Prevalence of Coronary Artery Disease in Pancreas Transplant Candidates with Type 1 Diabetes: A Cross Sectional Study

Pancreas transplantation is considered a high-risk surgery with cardiovascular complications. Early detection of all potential cardiovascular risk factors can decrease the perioperative risk and improve the pancreas recipients' outcome. The present study aims to evaluate the association between serum uric acid (UA) levels and the prevalence of coronary artery disease (CAD) in patients eligible for pancreas transplantation. We prospectively enrolled 63 consecutive patients with type 1 diabetes (T1D) who underwent cardiological evaluation before pancreas transplantation in our center. Participants underwent clinical evaluation, laboratory assays, and coronary angiography. The median concentration of UA in patients with CAD was significantly higher than in participants without CAD (6.43 (4.93-7.26) vs. 4.41 (3.64-5.49) mg/dL, p = 0.0002). We showed the positive correlation between UA concentration and systolic blood pressure, pulse pressure (PP) and triglycerides (r = 0.271, p = 0.032; r = 0.327, p = 0.009; r = 0.354, p = 0.004, respectively). In a multivariate analysis, the concentration of UA (OR 2.044; 95% CI: 1.261-3.311, p = 0.004) was independently associated with the prevalence of CAD in pancreas transplant candidates with T1D. We demonstrated that elevated UA levels were strongly associated with the high prevalence of CAD in pancreas transplant candidates with T1D. To stratify cardiovascular risk, the measurement of the UA concentration should be considered in all T1D patients qualified for pancreas transplantation.

Hyperuricemia Is Associated With the Risk of Atrial Fibrillation Independent of Sex: A Dose-Response Meta-Analysis

Background:

Conflicting findings of the association between serum uric acid (SUA) and atrial fibrillation (AF) have been reported in both men and women. The sex-specific associations between SUA and the risk of AF are unclear, although hyperuricemia is independently associated with the risk of AF. We performed this meta-analysis to assess the sex-specific effect of SUA on the risk of AF.

Methods

The PubMed, EMBASE, and Cochrane Library databases were searched up to October 3, 2021, for studies that reported sex-specific associations of SUA levels with AF. Linear relationships were assessed by the generalized least squares trend estimation. This study was registered with PROSPERO (42020193013).

Results

Ten eligible studies with 814,804 participants (415,779 men and 399,025 women) were identified. In the category analysis, high SUA was associated with an increased risk of AF in both men (OR: 1.42; 95% CI, 1.18–1.71, I² = 34%) and women (OR: 2.02; 95% CI, 1.29–3.16, I² = 70%). In the dose-response analysis, for each 60 μmol/L (1 mg/dL) increase in the SUA level, the risk of AF increased by 15% (OR: 1.15; 95% CI, 1.07–1.25, I² = 74%) in men and 35% (OR: 1.35; 95% CI, 1.18–1.53, I² = 73%) in women. There was a borderline difference in the impact of SUA on the risk of AF between men and women (P for interaction = 0.05). A significant linear relationship between SUA and the risk of AF was observed in men (P for non-linearity = 0.91) and women (P for non-linearity = 0.92).

Conclusions

This study suggested that there was a significant linear relationship between SUA and the risk of AF among men and women, with a higher risk estimate for women. Additional trials are required to assess the effect of reduced SUA therapy on AF incidence.

Systematic Review Registration

https:www.crd.york.ac.uk/PROSPERO/, identifier: CRD 42020193013.

Impact of hyperuricemia on chronic kidney disease and atherosclerotic cardiovascular disease

Hyperuricemia is caused by reduced renal/extrarenal excretion and overproduction of uric acid. It is affected by genetic predisposition related to uric acid transporters and by visceral fat accumulation due to overnutrition. The typical symptomatic complication of hyperuricemia is gout caused by monosodium urate crystals. Accumulated evidence from epidemiological studies suggests that hyperuricemia is also a risk factor for hypertension, chronic kidney disease (CKD) and atherosclerotic cardiovascular disease (CVD). However, it remains to be determined whether urate-lowering therapy for asymptomatic patients with hyperuricemia is effective in preventing CKD or CVD progression. This mini review focuses mainly on recent papers investigating the relationship between hyperuricemia and CKD or CVD and studies of urate-lowering therapy. Accumulated studies have proposed mechanisms of renal damage and atherosclerosis in hyperuricemia, including inflammasome activation, decreased nitric oxide bioavailability and oxidative stress induced by uric acid, urate crystals and xanthine oxidoreductase (XOR)-mediated reactive oxygen species. Since patients with hyperuricemia are a heterogeneous population with complex pathologies, it may be important to assess whether an outcome is the result of decreasing serum uric acid levels or an inhibitory effect on XOR. To clarify the impact of hyperuricemia on CKD and CVD progression, high-quality and detailed clinical and basic science studies of hyperuricemia and purine metabolism are needed.

Prospective Study of Serum Uric Acid Levels and First Stroke Events in Chinese Adults With Hypertension

Objectives: We investigated the association between serum uric acid (SUA) levels and the risk of the first stroke in Chinese adults with hypertension.

Methods: A total of 11, 841 hypertensive patients were selected from the Chinese Hypertension Registry for analysis. The relationship between SUA levels and first stroke was determined using multivariable Cox proportional hazards regression, smoothing curve fitting, and Kaplan–Meier survival curve analysis.

Results: During a median follow-up of 614 days, 99 cases of the first stroke were occurred. Cox proportional hazards models indicated that SUA levels were not significantly associated with the first stroke event [adjusted-hazard ratio (HR) per SD increase: 0.98, 95% CI 0.76–1.26, P = 0.889]. In comparison to the group without hyperuricemia (HUA), there were no significantly higher risks of first stroke events (adjusted-HR: 1.22, 95% CI 0.79–1.90, P = 0.373) in the population with HUA. However, in the population less than 60 years old, subjects with HUA had a significantly higher risk of the first stroke than the population without HUA (adjusted-HR: 4.89, 95% CI 1.36–17.63, P = 0.015). In subjects older than 60 years, we did not find a significant relationship between HUA and first stroke (adjusted-HR: 0.97, 95% CI 0.60–1.56, P = 0.886). Survival analysis further confirmed this discrepancy (log-rank P = 0.013 or 0.899 for non-aging or aging group).

Conclusion: No significant evidence in the present study indicated that increased SUA levels were associated with the risk of first stroke in the Chinese adults with hypertension. Age played an interactive role in the relationship between HUA and the first stroke event.

The Serum Uric Acid to Serum Creatinine Ratio is an Independent Risk Factor for Diabetic Kidney Disease

PURPOSE

A retrospective study was designed to evaluate whether the serum uric acid to serum creatinine ratio (SUA/SCr) can be used as an indicator of diabetic kidney disease (DKD) and macroangiopathy in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

We screened 2227 patients diagnosed with T2DM, and 450 patients were finally included. They were assigned to three groups based on the tertile of SUA/SCr (Group Tertile 1, Tertile 2, Tertile 3). Demographic information and biochemical parameters were collected from Electronic Patient Record (EPR).

RESULTS

The estimated glomerular filtration rate (eGFR) values were lowest in Group Tertile 1 and highest in Group Tertile 3 (P < 0.05). There was no significant difference in urinary albumin creatinine ratio (UACR) among the three groups (P > 0.05). Partial correlation analyses revealed that SUA/SCr levels were significantly and positively correlated with eGFR, SUA, body mass index, gamma-glutamyl transpeptidase, alanine transaminase, triglycerides, C-peptide, high-density lipoprotein cholesterol and fatty liver, while they were negatively correlated with SCr, blood urea nitrogen, cystatin-c, age, male sex, DM duration and hypertension history (P < 0.05). Logistic regression analysis revealed that SUA/SCr was an independent risk factor for eGFR < 60 mL/min/1.73 m² (P < 0.05). The ROC curve showed that the cutoff value of SUA/SCr for the identification of eGFR < 60 mL/min/1.73 m² was 3.434. In patients with normal UACR, SUA/SCr levels of patients with eGFR < 60 mL/min/1.73 m² were lower than those with eGFR ≥ 60 mL/min/1.73 m² (P < 0.05). Regression analysis did not show SUA/SCr associate to macrovascular disease after adjusting for confounding factors.

CONCLUSION

SUA/SCr is an independent risk factor for DKD in patients with T2DM and may be helpful for identifying normoalbuminuric DKD.

Annual reports on hypertension research 2020

In 2020, 199 papers were published in Hypertension Research. Many excellent papers have contributed to progress in research on hypertension. Here, our editorial members have summarized eleven topics from published work and discussed current topics in depth. We hope you enjoy our special feature, Annual Reports on Hypertension Research.

Metabolic Factors Mediate the Association Between Serum Uric Acid to Serum Creatinine Ratio and Cardiovascular Disease

Background

The serum uric acid/serum creatinine ratio (SUA/SCr), which represents renal function‐normalized SUA, is associated with diverse adverse outcomes. The aim of this study was to investigate the association between SUA/SCr and cardiovascular disease (CVD), and determine whether and to what extent this association is mediated by cardiometabolic factors.

Methods and Results

This prospective study enrolled 96 378 participants from the Kailuan study without stroke and myocardial infarction at baseline (2006). Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Mediation analyses were conducted to separately explore the mediating effects of cardiometabolic factors on the association between SUA/SCr and CVD. During median follow up of 11.01 years, 6315 (6.55%) individuals developed incident CVD. After adjustment for potential confounders, the highest quartile of SUA/SCr was associated with the highest risk of CVD (HR, 1.15; 95% CI, 1.07–1.23), stroke (HR, 1.16; 95% CI, 1.07–1.26), ischemic stroke (HR, 1.12; 95% CI, 1.02–1.22), and hemorrhagic stroke (HR, 1.36; 95% CI, 1.11–1.65), but not with myocardial infarction (HR, 1.07; 95% CI, 0.92–1.25). The association was consistent across different degrees of kidney function and glucose tolerance statuses. Additionally, the association between high SUA/SCr and CVD was partially mediated by triglycerides (30.74%), body mass index (BMI) (19.52%), total cholesterol (15.06%), hs‐CRP (high‐sensitivity C‐reactive protein) (13.06%), diastolic blood pressure (11.75%), and blood glucose (−16.38%).

Conclusions

SUA/SCr and CVD were positively associated. Furthermore, this association was partially mediated through blood lipids, BMI, blood pressure, hs‐CRP, and blood glucose.

Should we be more aware of gender aspects in hyperuricemia? Analysis of the population-based German health interview and examination survey for adults (DEGS1)

OBJECTIVES

While gout is a well-known entity, little research has been conducted on its pathophysiology. There is growing evidence that women with hyperuricemia are at higher cardiovascular risk than men with hyperuricemia. We aim to evaluate whether gender-specific cut-offs should be considered.

STUDY DESIGN

Cross-sectional study (the German Health Interview and Examination Survey for Adults; DEGS1).

MAIN OUTCOME MEASURES

Self-reported gout or hyperuricemia and uric acid level.

RESULTS

Of 6,918 participants (mean age 47.2 years; 50.5% females), 9.7% had had a diagnosis of hyperuricemia or gout at least once in their lifetime. Men were nearly twice as often affected as women (12.9 vs. 6.5%). In women, the prevalence of cardiovascular and renal diseases increased with higher uric acid level to a much greater extent than in men. This association remained in multivariate analyses.

CONCLUSIONS

No commonly accepted cut-off value for uric acid has been established. Overall, women were at lower risk of hyperuricemia. However, women were at higher risk of having cardiovascular and renal comorbidities, even at lower uric acid levels. Our results are in line with the accumulating evidence that we should consider gender in gout and hyperuricemia.

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.

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

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

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

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

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

No association between serum uric acid and lumbar spine bone mineral density in US adult males: a cross sectional study

Available evidence linking serum uric acid (SUA) and bone mineral density (BMD) remains controversial, and data on this association are limited among adult men in the general population. Thus, the aim of this study was to evaluate the association of SUA with lumbar spine BMD in US adult males. A cross-sectional study was conducted based on the National Health and Nutrition Examination Survey (NHANES, 1999–2006) database. Multivariate linear regression analyses were employed to assess the association of SUA with lumbar spine BMD, considering complex survey design and sampling weights. Through rigorous eligibility criteria, a total of 6704 individuals were yielded for final data analysis (average age, 40.5 years; 70.6% white). After fully adjusting potential confounders, no associations were detected between SUA and lumbar spine BMD [β (95% confidence interval, CI), − 0.003 (− 0.007, 0.002)]. Additionally, similar results were observed in all stratification analyses, and no interactions were found based on all priori specifications. In brief, our findings did not provide an inspiring clue for the hypothesis that SUA may be beneficial to lumbar spine BMD. Future more prospective studies are needed to further explore the causal relationship of SUA with lumbar spine BMD.

J-shaped curve for the association between serum uric acid levels and the prevalence of blood pressure abnormalities

Low and high serum uric acid levels are associated with an increased risk of cardiovascular diseases. However, whether there is a similar association between serum uric acid levels and blood pressure abnormalities has not yet been elucidated. Data from 236,221 individuals (age, 56.0 ± 15.0 years; 107,146 men) who underwent routine health checkups were analyzed. Participants with a serum uric acid level ≤2.0 mg/dL were separated, and the remaining participants were divided into quartiles according to their serum uric acid levels. Among each group, the proportions of participants with high blood pressure (≥130/80 mmHg, and/or medication) and hypertension (≥140/90 mmHg, and/or medication), were calculated. The adjusted odds ratio of each group compared to the group with the lowest proportion of blood pressure abnormalities was calculated. The participants were divided into five groups according to their serum uric acid levels, ≤2.0, 2.1-4.0, 4.1-5.0, 5.1-6.0, and ≥6.1 mg/dL, and the prevalence of high blood pressure was 49.0, 44.6, 52.3, 58.6, and 65.3% and that of hypertension was 31.0, 27.4, 33.5, 38.7, and 43.8%, respectively. Compared to the second-lowest serum uric acid group (2.1-4.0 mg/dL), groups with higher serum uric acid levels (4.1-5.0, 5.1-6.0, and ≥6.1 mg/dL), as well as the group with the lowest serum uric acid level (≤2.0 mg/dL), showed significantly higher odds ratios for high blood pressure and hypertension. High and low serum uric acid levels were significantly associated with an increased prevalence of high blood pressure and followed a J-shaped curve.

Association Between Uric Acid, Carotid Intima-Media Thickness, and Cardiovascular Events: Prospective Results From the IMPROVE Study

Background The association between elevated serum uric acid (SUA), cardiovascular disease (CVD) risk, and carotid atherosclerosis has long been explored, and contrasting results have been reported. Therefore, the role of SUA as an independent risk factor for vascular events (VEs) and carotid atherosclerosis deserves further attention. We investigated the relationship between SUA, incident VEs, carotid intima-media thickness (cIMT), and cIMT progression in subjects at moderate-to-high CVD risk. Methods and Results In the IMPROVE (IMT-Progression as Predictors of VEs) study, 3686 participants (median age 64 years; 48% men) with ≥ 3 vascular risk factors, free from VEs at baseline, were grouped according to SUA quartiles (division points: 244-284-328 µmol/L in women, 295-336-385 µmol/L in men). Carotid-IMT and its 15-month progression, along with incident VEs, were recorded. A U-shaped association between SUA and VEs was observed in men, with 2.4-fold (P = 0.004) and 2.5-fold (P = 0.002) increased CVD risk in the first and fourth SUA quartiles as compared with the second. Adjusted hazard ratios (HRs) for cerebro-VEs in men were the highest (first and fourth quartile versus second: HR, 5.3, P = 0.010 and HR, 4.4, P = 0.023, respectively). SUA level was independently associated with cIMT progression in men (β = 0.068, P = 0.014). No significant association between SUA levels, CVD end points, and cIMT progression were found in women. Conclusions Both low and high SUA levels are associated with an increased risk of VEs in men at moderate-to-high CVD risk but not in women. Only elevated SUA levels predict cIMT progression and at a lesser but not significant extent in women.

Serum metabolomic patterns in young patients with ischemic stroke: a case study

BACKGROUND

Ischemic stroke is one of the leading causes of death and adult disability. The incidence of ischemic stroke continues to rise in young adults. This study aimed to provide a comprehensive evaluation of metabolic changes and explore possible mechanisms in young ischemic stroke patients without common risk factors.

METHODS

This study investigated serum metabolomics in 50 young patients with newly suffered ischemic stroke and 50 age-, sex-, and body mass index-matched healthy controls. Liquid chromatography coupled with a Waters Xevo TQ-S mass spectrometer with an electrospray ionization (ESI) source was used to analyze amino acid or bile acid, and free fatty acid or lipid was analyzed by liquid chromatography coupled with a Qtrap5500 mass spectrometer with an ESI source. The metabolomic data were analyzed by performing a multivariate statistical analysis.

RESULTS

A total of 197 metabolites, including amino acids, bile acids, free fatty acids, and lipids, were identified in all participants. Multivariate models showed significant differences in serum metabolomic patterns between young patients with ischemic stroke and healthy controls. The stroke patients had increased L-methionine, homocysteine, glutamine, uric acid, GCDCA, and PE (18:0/20:4, 16:0/22:5), and decreased levels of L-citrulline, taurine, PC (16:2/22:6, 16:2/20:5, 15:0/18:2), and SM (d18:1/23:0, d20:0/19:1, d18:1/22:0, d16:0/26:1, d16:0/18:0, d16:0/22:1, d18:1/19:1, d16:0/17:1, d16:1/24:1, d18:1/19:0). Based on the identified metabolites, the metabolic pathways of arginine biosynthesis, glycerophospholipid metabolism, and taurine and hypotaurine metabolism were significantly enriched in the young patients with ischemic stroke.

CONCLUSIONS

Serum metabolomic patterns were significantly different between young patients with ischemic stroke and healthy controls. Our study is beneficial in providing a further view into the pathophysiology of young patients with ischemic stroke.

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

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