Relationship between serum uric acid level and vascular injury markers in hemodialysis patients

Endothelial function, arterial stiffness and Framingham risk score in chronic kidney disease: A prospective observational cohort study

The aim of this study was to assess the role of endothelial function measured by the reactive hyperemia index (RHI), arterial stiffness measured by the augmentation index (AIx), and Framingham's cardiovascular disease (CVD) risk score (FRS) in kidney function decline in patients with chronic kidney disease (CKD). The RHI and AIx@75 (adjusted for 75 heart beats per minute), both derived from peripheral arterial tonometry (EndoPAT), were measured in 428 CKD patients aged 18 years old and older during hospitalization. We evaluated kidney function and its decline (incident ≥40% decline in estimated glomerular filtration rate [eGFR] or initiation of renal replacement therapy) associated with the RHI, AIx@75, and FRS during follow-up for a median of 36 months. The mean age of the participants was 56 years old, and 63.8% were men. In Spearman correlation analysis, the FRS, AIx@75, and RHI levels inversely correlated with eGFR. Over a median follow-up of 36 months, 122 participants experienced kidney function decline. In multivariate Cox analysis, only the FRS remained independently associated with the progression of kidney function (HR, 1.37; 95% CI, 1.14 to 1.64; P = 0.001). Multivariable-adjusted spline regression models showed a positive linear relationship between the FRS and the risk of kidney function decline (P-overall = 0.001, P-nonlinear = 0.701). However, adding the FRS to a model containing kidney function markers did not improve risk prediction for kidney outcome (category-free net reclassification improvement index [cf-NRI] = 0.179, P = 0.084; integrated discrimination improvement [IDI] = 0.017, P = 0.128). Additionally, the increased risk of the outcome associated with an elevated FRS was particularly evident among CKD patients with eGFR ≥60 ml/min/1.73  m² (eGFR ≥ 60 ml/min/1.73 m² vs.< 60 ml/min/1.73 m², P for interaction =  0.022). Participants with higher FRS levels were at increased risk of kidney function decline, emphasizing the important role of traditional CVD risk factors in the progression of CKD.

Possible Clinical Benefits of Cardio-Ankle Vascular Index Measurement in Urological Diseases

Many factors are considered to affect vascular physiology. It is known that one of the reasons for many diseases is a pathology at the microvascular level. Therefore, the relationship between endothelial dysfunction and many diseases is currently being investigated. The clinical evaluations of arterial stiffness have made it possible to perform necessary risk assessment regarding cardiovascular diseases. In this way, protective measures can be taken against microvascular pathologies in many organs. In this paper, we present a review of studies investigating the relationship between urological conditions and the cardio-ankle vascular index (CAVI), a marker of arterial stiffness. As with erectile dysfunction, some studies have shown that conditions such as lower urinary tract symptoms, overactive bladder, and chronic kidney disease are also associated with an elevated CAVI. The association of erectile dysfunction and chronic kidney disease with vascular pathologies has been clearly demonstrated. In addition, lower urinary tract symptoms may be the first sign of silent vascular dysfunction. Assessing arterial stiffness with CAVI can help prevent future cardiovascular events in these patients.

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.

Meta-analysis of the correlation between serum uric acid level and carotid intima-media thickness

Objective

Recently, increasing epidemiological evidence has shown that there is a correlation between serum uric acid level (SUA) and carotid intima-media thickness (CIMT). This paper explored the relationship between them through meta-analysis.

Methods

PubMed, Cochrane Library, EMBASE, Web of Science and Google Scholar were searched to obtain literature. The keywords used to retrieve the literature were carotid intima thickness, intima-media thickness, carotid atherosclerosis, carotid stenosis, carotid artery, uric acid, blood uric acid, and hyperuricaemia. The retrieval time was from the establishment of the database through July 2020. Stata15.0 and RevMan5.3 software were used for statistical analysis. The standardized mean difference (SMD) and 95% confidence interval (95% CI) were calculated by a random effect model to estimate the correlation. Publication bias was assessed using the Begg and Egger tests. The stability of these results was evaluated using sensitivity analyses.

Results

Fifteen studies were included with a total sample size of 11382, including 7597 participants in the high uric acid group and 3785 in the control group, on the basis of the inclusion and exclusion criteria. According to the evaluation of the JBI scale, the literature was of high quality. The average age ranged from 42 to 74. Meta-analysis showed that CIMT in the high uric acid group was significantly higher than that in the control group (SMD = 0.53, 95% CI: [0.38, 0.68]), and the difference was significant (z = 6.98, P < 0.00001). The heterogeneity among the 15 articles was obvious (I² = 89%, P < 0.00001). Subgroup analysis by disease status illustrated a positive relationship between SUA and CIMT in healthy people and people with diseases. SUA was shown to be positively correlated with CIMT in people aged 45–60 years and ≥60 years by subgroup analysis by age. SUA was also found to be positively correlated with CIMT in a population with BMI>24 kg/m² by subgroup analysis by BMI. In addition, subgroup analysis of other risk factors for CIMT, including TC, SBP, DBP, triglycerides, and LDL-C, all showed a positive correlation between SUA and CIMT.

Conclusions

There is a significant correlation between serum uric acid level and carotid intima-media thickness, and a high concentration of serum uric acid is related to carotid artery intima-media thickness.