Interactions Between Kidney Function and Cerebrovascular Disease: Vessel Pathology That Fires Together Wires Together

Logistic regression model for predicting risk factors and contribution of cerebral microbleeds using renal function indicators

Background

The brain and kidneys share similar low-resistance microvascular structures, receiving blood at consistently high flow rates and thus, are vulnerable to blood pressure fluctuations. This study investigates the causative factors of cerebral microbleeds (CMBs), aiming to quantify the contribution of each risk factor by constructing a multivariate model via stepwise regression.

Methods

A total of 164 hospitalized patients were enrolled from January 2022 to March 2023 in this study, employing magnetic susceptibility-weighted imaging (SWI) to assess the presence of CMBs. The presence of CMBs in patients was determined by SWI, and history, renal function related to CMBs were analyzed.

Results

Out of 164 participants in the safety analysis, 36 (21.96%) exhibited CMBs and 128 (78.04%) did not exhibit CMBs, and the median age of the patients was 66 years (range: 49-86 years). Multivariate logistic regression identified hypertension (OR = 13.95%, 95% CI: 4.52, 50.07%), blood urea nitrogen (BUN) (OR = 1.57, 95% CI: 1.06-2.40), cystatin C (CyC) (OR = 4.90, 95% CI: 1.20-22.16), and urinary β-2 microglobulin, (OR = 2.11, 95% CI: 1.45-3.49) as significant risk factors for CMBs. The marginal R-square (R M 2 ) was 0.25. Among all determinants, hypertension (47.81%) had the highest weight, followed by UN (11.42%). Quasi-curves plotted using the bootstrap method (999 times) showed good agreement between the predictive model and actual observations.

Conclusion

Hypertension, BUN, urinary β-2 microglobulin, CyC were risk factors for CMBs morbidity, and controlling the above indicators within a reasonable range will help to reduce the incidence of CMBs.

Burden and determinants of renal dysfunction and in-hospital mortality among acute stroke patients in Ethiopia: A hospital-based observational study

Stroke, a leading global cause of mortality and neurological impairment, is often complicated by renal failure, exacerbating in-hospital risks and mortality. Limited understanding exists regarding renal failure prevalence in Ethiopian acute stroke patients. This study examines renal function abnormalities in acute stroke patients at Jimma Medical Center (JMC). A hospital-based cross-sectional study was conducted at JMC from December 5, 2023, to March 15, 2024. A structured data collection tool was developed after comprehensive review of pertinent literature, encompassing variables pertinent to the study objectives. Following data quality assurance, information was coded and inputted into EpiData version 3.1, subsequently analyzed using Statistical Package for Social Sciences (SPSS) version 26.0. Multivariable logistic regression analysis was performed to adjust for confounding variables, with statistical significance set at P < .05. The mean age of participants was 60.5 ± 15.5 years, with 129 (64.5%) being male. Forty-five participants (22.5%, 95% confidence interval [CI] = 16.9, 28.9) exhibited renal dysfunction. Advanced age (≥70 years), hypertension, diabetes mellitus (DM), cardiac disease, history of transient ischemic attack (TIA)/stroke, and hemorrhagic stroke type were identified as significant predictors of renal dysfunction among hospitalized stroke patients. The mortality rate was 3.7 times higher in stroke patients with renal dysfunction compared to those with normal renal function (adjusted odds ratio [AOR] = 3.7, 95% CI: 1.41, 6.22). Renal function abnormalities were prevalent among hospitalized acute stroke patients, emphasizing the significance of renal dysfunction as a frequent comorbidity. Older age, hypertension, DM, cardiac disease, history of TIA/stroke, and hemorrhagic stroke type emerged as statistically significant predictors of renal dysfunction. Furthermore, renal dysfunction was identified as a significant predictor of in-hospital mortality following stroke.

Kidney dysfunction predicts 90 days mortality after stroke thrombectomy independent of cardiovascular risk factors and chronic kidney disease

INTRODUCTION

Kidney dysfunction (KD) is a risk factor for cerebrovascular events and has been shown to have a detrimental effect on outcome after stroke. We evaluated the influence of KD at admission and pre-existing diagnosis of chronic kidney disease (CKD) before thrombectomy for anterior circulation stroke on functional independence and mortality 90 days after stroke in this cross-sectional study.

PATIENTS AND METHODS

We included patients with acute ischemic stroke in the anterior circulation treated with thrombectomy at our hospital between June 2015 and May 2022. We analyzed clinical characteristics, laboratory values and pre-existing diagnosis of CKD. KD at admission was defined as glomerular filtration rate (GFR) <60 ml/min/1.73 m2. Outcomes were defined as a modified Rankin Scale Score of 0-2 for functional independence and mortality at 90 days. We fitted multivariate regression analysis to examine the influence of pre-treatment KD and pre-diagnosed CKD on outcome.

RESULTS

Nine hundred fifty-three patients were included in this analysis (mean age 73.8 years, 54.2% female). KD was present in 31.8%, and patients with KD were older and more often female, presented more often with comorbidities such as arterial hypertension, diabetes, and atrial fibrillation, and were less often independent before the index stroke. In multivariate analysis adjusted for age, independence before the index stroke, diabetes, hypertension, atrial fibrillation, initial NIHSS, thrombolysis treatment, and recanalization outcome, KD on admission had no significant influence on functional independence 90 days after stroke, but predicted mortality with an odds ratio of 1.80 (95% CI 1.23-2.63, p = 0.003). This influence also persisted when controlling for pre-diagnosed CKD (OR 1.60, 95% CI 1.05-2.43, p = 0.027).

DISCUSSION

KD might function as a surrogate parameter for comorbidity burden and thus increased risk of mortality in this cohort.

CONCLUSIONS

KD on admission is associated with an 80% higher risk of mortality at 90 days after stroke thrombectomy independent of cardiovascular risk factors and CKD awareness. KD on admission should not exclude patients from thrombectomy but might support prognostic evaluation.

Cystatin C-based estimated glomerular filtration rate and risk of stroke in the general population: a prospective cohort study

Background

Previous results on the association between the estimated glomerular filtration rate (eGFR) and stroke are mixed. Most studies derived the eGFR from serum creatinine, which is affected by non-kidney determinants and thus has possibly biased the association with stroke risk.

Methods

In this cohort study, we included 429 566 UK Biobank participants (94.5% white, 54% women, age 56 ± 8 years) free of stroke at enrollment. The eGFRcys and eGFRcr were calculated with serum cystatin C and creatinine, respectively. Outcomes of interest were risk of total stroke and subtypes. We investigated the linear and nonlinear associations using Cox proportional hazards models and restricted cubic splines, corrected for regression dilution bias.

Results

During an average follow-up of 10.11 years, 4427 incident strokes occurred, among which 3447 were ischemic and 1163 were hemorrhagic. After adjustment for confounders, the regression dilution-corrected hazard ratios (95% confidence intervals) for every 10 mL/min/1.73 m2 decrement in eGFRcys were 1.10 (1.05-1.14) for total stroke and 1.11 (1.08-1.15) for ischemic stroke. A similar pattern was observed with eGFRcr, although the association was weaker. When either type of eGFR was below 75 mL/min/1.73 m2, the risks of total and ischemic stroke increased exponentially as eGFR decreased. A U-shaped relationship was witnessed if eGFRcr was used instead. There was a null association between eGFR and hemorrhagic stroke.

Conclusions

The risks of total stroke and ischemic stroke increased exponentially when the eGFRcys fell below 75 mL/min/1.73 m2.

Associations of renal function with cerebral small vessel disease and functional outcome in acute intracerebral haemorrhage: A hospital-based prospective cohort study

BACKGROUND

Intracerebral haemorrhage (ICH) is a severe clinical consequence of cerebral small vessel disease (SVD), but associations between renal impairment and SVD in patients with ICH have not been fully characterised.

METHODS

Using data from the CROMIS-2 ICH observational study, we compared SVD neuroimaging markers and total burden (score 0-3) identified using CT brain imaging in patients with and without renal impairment (estimated glomerular filtration rate, eGFR<60). We assessed functional outcome at 6-month follow-up using the modified Rankin scale.

RESULTS

1027 participants were included (mean age 72.8, 57.1% male); 274 with and 753 without renal impairment. 18.7% of the eGFR<60 group had moderate-to-severe SVD burden (score 2-3), compared with 14.0% of those with eGFR>60 (p = 0.039). SVD burden was associated with renal impairment after adjusting for hypertension (OR 1.36, 95% CI 1.04-1.77, p = 0.023), but not after adjusting for age. Cerebral atrophy was more prevalent in patients with eGFR<60 (81.2% vs. 72.0%, p = 0.002), as were WMH (45.6% vs. 36.6%, p = 0.026). Neither was associated with renal function after adjusting for age and vascular risk factors. Renal impairment was associated with functional outcome (OR 0.65, 95% CI 0.47-0.89, p = 0.007), but not after adjusting for age, pre-morbid function and comorbidities (OR 0.95, 95% CI 0.65-1.38, p = 0.774).

CONCLUSION

In acute ICH, renal impairment is associated with a higher cerebral SVD burden independent of hypertension, but not age. Reduced eGFR is associated with worse functional outcome, but not independent of age and comorbidities. Since CT has limited sensitivity to detect SVD severity and distribution, further studies including MRI are needed.

Role of Cardio-Renal Dysfunction, Inflammation Markers, and Frailty on In-Hospital Mortality in Older COVID-19 Patients: A Cluster Analysis

Our study aimed to identify clusters of hospitalized older COVID-19 patients according to their main comorbidities and routine laboratory parameters to evaluate their association with in-hospital mortality. We performed an observational study on 485 hospitalized older COVID-19 adults (aged 80+ years). Patients were aggregated in clusters by a K-medians cluster analysis. The primary outcome was in-hospital mortality. Medical history and laboratory parameters were collected on admission. Frailty, defined by the Clinical Frailty Scale (CFS), referred to the two weeks before hospitalization and was used as a covariate. The median age was 87 (83-91) years, with a female prevalence (59.2%). Three different clusters were identified: cluster 1 (337), cluster 2 (118), and cluster 3 (30). In-hospital mortality was 28.5%, increasing from cluster 1 to cluster 3: cluster 1 = 21.1%, cluster 2 = 40.7%, and cluster 3 = 63.3% (p < 0.001). The risk for in-hospital mortality was higher in clusters 2 [HR 1.96 (95% CI: 1.28-3.01)] and 3 [HR 2.87 (95% CI: 1.62-5.07)] compared to cluster 1, even after adjusting for age, sex, and frailty. Patients in cluster 3 were older and had a higher prevalence of atrial fibrillation, higher admission NT-proBNP and C-reactive protein levels, higher prevalence of concurrent bacterial infections, and lower estimated glomerular filtration rates. The addition of CFS significantly improved the predictive ability of the clusters for in-hospital mortality. Our cluster analysis on older COVID-19 patients provides a characterization of those subjects at higher risk for in-hospital mortality, highlighting the role played by cardio-renal impairment, higher inflammation markers, and frailty, often simultaneously present in the same patient.

Common clinical blood and urine biomarkers for ischemic stroke: an Estonian Electronic Health Records database study

BACKGROUND

Ischemic stroke (IS) is a major health risk without generally usable effective measures of primary prevention. Early warning signals that are easy to detect and widely available can save lives. Estonia has one nation-wide Electronic Health Record (EHR) database for the storage of medical information of patients from hospitals and primary care providers.

METHODS

We extracted structured and unstructured data from the EHRs of participants of the Estonian Biobank (EstBB) and evaluated different formats of input data to understand how this continuously growing dataset should be prepared for best prediction. The utility of the EHR database for finding blood- and urine-based biomarkers for IS was demonstrated by applying different analytical and machine learning (ML) methods.

RESULTS

Several early trends in common clinical laboratory parameter changes (set of red blood indices, lymphocyte/neutrophil ratio, etc.) were established for IS prediction. The developed ML models predicted the future occurrence of IS with very high accuracy and Random Forests was proved as the most applicable method to EHR data.

CONCLUSIONS

We conclude that the EHR database and the risk factors uncovered are valuable resources in screening the population for risk of IS as well as constructing disease risk scores and refining prediction models for IS by ML.

The kidney-brain pathogenic axis in severe falciparum malaria

Severe falciparum malaria is a medical emergency and a leading cause of death and neurodisability in endemic areas. Common complications include acute kidney injury (AKI) and cerebral malaria, and recent studies have suggested links between kidney and brain dysfunction in Plasmodium falciparum infection. Here, we review these new findings and present the hypothesis of a pivotal pathogenic crosstalk between the kidneys and the brain in severe falciparum malaria. We highlight the evidence of a role for distant organ involvement in the development of cerebral malaria and subsequent neurocognitive impairment post-recovery, describe the challenges associated with current diagnostic shortcomings for both AKI and brain involvement in severe falciparum malaria, and explore novel potential therapeutic strategies.

Progress on Prevention and Treatment of Cerebral Small Vascular Disease Using Integrative Medicine

Cerebral small vessel disease (CSVD) is a senile brain lesion caused by the abnormal structure and function of arterioles, venules and capillaries in the aging brain. The etiology of CSVD is complex, and disease is often asymptomatic in its early stages. However, as CSVD develops, brain disorders may occur, such as stroke, cognitive dysfunction, dyskinesia and mood disorders, and heart, kidney, eye and systemic disorders. As the population continues to age, the burden of CSVD is increasing. Moreover, there is an urgent need for better screening methods and diagnostic markers for CSVD, in addition to preventive and asymptomatic- and mild-stage treatments. Integrative medicine (IM), which combines the holistic concepts and syndrome differentiations of Chinese medicine with modern medical perspectives, has unique advantages for the prevention and treatment of CSVD. In this review, we summarize the biological markers, ultrasound and imaging features, disease-related genes and risk factors relevant to CSVD diagnosis and screening. Furthermore, we discuss IM-based CSVD prevention and treatment strategies to stimulate further research in this field.

From Kidney Protection to Stroke Prevention: The Potential Role of Sodium Glucose Cotransporter-2 Inhibitors

Chronic kidney disease (CKD) is an independent risk factor for stroke and covert cerebrovascular disease, and up to 40% of stroke patients have concomitant CKD. However, the so-called "cerebrorenal interaction" attracted less attention compared to its cardiorenal counterpart. Diabetes is the leading cause of CKD. The sodium-glucose cotransporter (SGLT) 2 inhibitor is a relatively new class of oral anti-diabetic drugs and has cardiorenal benefits in addition to glucose-lowering effects. In the present perspective, we would like to review the current status and future potential of the SGLT2 inhibitor in cerebro-renal interactions and strokes regardless of the status of diabetes. We propose the potential roles of baseline renal functions and SGLT1/2 dual inhibition in stroke prevention, as well as the additional benefits of reducing atrial fibrillation and hemorrhagic stroke for SGLT2 inhibitors. Further clinical trials are anticipated to test whether SGLT2 inhibitors can fulfill the long-standing unmet clinical need and stop such a vicious cycle of cerebro-renal interaction.

Microvascular Dysfunction as a Systemic Disease: A Review of the Evidence

Microvascular dysfunction describes a varied set of conditions that includes vessel destruction, abnormal vasoreactivity, in situ thrombosis, and fibrosis, which ultimately results in tissue damage and progressive organ failure. Microvascular dysfunction has a wide array of clinical presentations, ranging from ischemic heart disease to renal failure, stroke, blindness, pulmonary arterial hypertension, and dementia. An intriguing unifying hypothesis suggests that microvascular dysfunction of specific organs is an expression of a systemic illness that worsens with age and is accelerated by vascular risk factors. Studying relationships across a spectrum of microvascular diseases affecting the brain, retina, kidney, lung, and heart may uncover shared pathologic mechanisms that could inform novel treatment strategies. We review the evidence that supports the notion that microvascular dysfunction represents a global pathologic process. Our focus is on studies reporting concomitant microvascular dysfunction of the heart with that of the brain, kidney, retina, and lung.

A Systematic Review of the Impact of Physical Exercise-Induced Increased Resting Cerebral Blood Flow on Cognitive Functions

Brain perfusion declines with aging. Physical exercise represents a low-cost accessible form of intervention to increase cerebral blood flow; however, it remains unclear if exercise-induced amelioration of brain perfusion has any impact on cognition. We aimed to provide a state-of-the art review on this subject. A comprehensive search of the PubMed (MEDLINE) database was performed. On the basis of the inclusion and exclusion criteria, 14 studies were included in the analysis. Eleven of the studies conducted well-controlled exercise programs that lasted 12–19 weeks for 10–40 participants and two studies were conducted in much larger groups of subjects for more than 5 years, but the exercise loads were indirectly measured, and three of them were focused on acute exercise. Literature review does not show a direct link between exercise-induced augmentation of brain perfusion and better cognitive functioning. However, in none of the reviewed studies was such an association the primary study endpoint. Carefully designed clinical studies with focus on cognitive and perfusion variables are needed to provide a response to the question whether exercise-induced cerebral perfusion augmentation is of clinical importance.

Brain Asymmetry: Towards an Asymmetrical Neurovisceral Integration

Despite the ancestral evidence of an asymmetry in motor predominance, going through the inspiring discoveries of Broca and Wernicke on the localization of language processing, continuing with the subsequent noise coinciding with the study of brain function in commissurotomized patients—and the subsequent avalanche of data on the asymmetric distribution of multiple types of neurotransmitters in physiological and pathological conditions—even today, the functional significance of brain asymmetry is still unknown. Currently, multiple evidence suggests that functional asymmetries must have a neurochemical substrate and that brain asymmetry is not a static concept but rather a dynamic one, with intra- and inter-hemispheric interactions between its various processes, and that it is modifiable depending on changing endogenous and environmental conditions. Furthermore, based on the concept of neurovisceral integration in the overall functioning of an organism, some evidence has emerged suggesting that this integration could be organized asymmetrically, using the autonomic nervous system as a bidirectional communication pathway, whose performance would also be asymmetric. However, the functional significance of this distribution, as well as the evolutionary advantage of an asymmetric nervous organization, is still unknown.