Association of Intracranial Artery Calcification with Cognitive Impairment in Hemodialysis Patients

Prevalence of cognitive impairment and its predictors among chronic kidney disease patients: A systematic review and meta-analysis

BACKGROUND

Cognitive impairment (CI) is common among patients with chronic kidney disease (CKD), and is associated with a poor prognosis. We assessed the prevalence and associated factors of CI in patients with CKD.

METHODS

A systematic review and meta-analysis were conducted by searching PubMed, Embase, and the Web of Science through December 1, 2023. Random effects models were performed with subgroup analyses to further explore the heterogeneity.

RESULTS

50 studies involving 25,289 CKD patients were included. The overall prevalence of CI was 40% (95% confidence interval 33-46). The pooled prevalence of CI was relatively higher in CKD patients from Africa (58%), Asia (44%) and America (37%). Attention and executive dysfunction appeared to be the most common manifestations. The prevalence of CI was higher among patients with hemodialysis (53%) and peritoneal dialysis (39%) than those without dialysis (32%) and post-kidney transplanted (26%). In addition, advanced age, the presence of diabetes and hypertension might increase the risk of CI in CKD patients.

CONCLUSIONS

People with CKD have a high prevalence of CI, especially in patients with hemodialysis. An early and comprehensive screening for CI in CKD patients is needed to improve clinical outcomes.

TRIAL REGISTRATION

Registration number: PROSPERO (CRD42023412864).

Intracranial arteriosclerosis and the risk of dementia: A population-based cohort study

BACKGROUND

The impact of intracranial arteriosclerosis on dementia remains largely unclear.

METHODS

In 2339 stroke-free and dementia-free participants (52.2% women, mean age 69.5 years) from the general population, we assessed intracranial carotid artery calcification (ICAC) and vertebrobasilar artery calcification (VBAC) as proxy for arteriosclerosis. Associations with dementia were assessed using Cox models. In addition, indirect effects through cerebral small vessel disease (cSVD) and subcortical brain structure volumes were assessed using causal mediation analyses.

RESULTS

During a median of 13.4 years (25th-75th percentiles 9.9-14.5) of follow-up, 282 participants developed dementia. Both ICAC presence (hazard ratio [HR]: 1.53, 95% confidence interval [CI]: 1.00-2.32]) and volume (HR per standard deviation: 1.19, 95% CI: 1.01-1.40) increased dementia risk. For VBAC, severe calcifications increased dementia risk (HR for third vs first volume tertile: 1.89, 95% CI: 1.00-3.59). These effects were mediated partly through increased cSVD (percentage mediated for ICAC: 13% and VBAC: 24%).

DISCUSSION

Intracranial arteriosclerosis increases the risk of dementia.

Risk factors and prevalence of cognitive impairment in maintenance haemodialysis patients: A systematic review and meta-analysis of observational studies

AIMS

To systematically identify the risk factors for cognitive impairment in maintenance haemodialysis patients and to assess its prevalence in included studies.

DESIGN

Systematic review and meta-analysis about observational studies.

DATA SOURCES

Systematic search of seven databases, including PubMed, Web of Science, Scope, Wanfang Database, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and Weipu Chinese Science and Technology Journal Database, from inception until October 2021.

REVIEW METHODS

Observational studies reporting the risk factors for cognitive impairment in maintenance haemodialysis patients in English and Chinese language were included. Meta-analysis was performed to identify risk factors and prevalence of cognitive impairment in maintenance haemodialysis patients with STATA 15.0 software.

RESULTS

Overall, 37 eligible studies encompassing 129,849 cases were included. The risk factors with statistical significance after meta-analysis were older age, female sex, fewer years of education, hypertension, diabetes, cerebrovascular accident, multiple comorbid conditions, systolic blood pressure variability, arterial stiffness and low haemoglobin and albumin level. The overall prevalence of cognitive impairment in maintenance haemodialysis patients was 49.1%.

CONCLUSION

The current analysis indicated a high prevalence of cognitive impairment in maintenance haemodialysis patients. Eleven risk factors for cognitive impairment in maintenance haemodialysis patients were identified, among which more attention should be paid to modifiable factors such as cardiovascular disease risk factors and specific kidney and dialysis-related factors.

IMPACT

This paper provides an updated estimate of the pooled prevalence of cognitive impairment in maintenance haemodialysis patients. Identification of risk factors associated with cognitive impairment may assist in developing targeted prevention strategies for maintenance haemodialysis patients at high risk.

NO PATIENT OR PUBLIC CONTRIBUTION

This study was a systematic review completed by the authors in accordance with relevant guidelines and processes and did not include the participation of patients, service users, caregivers or the general public.

Intracranial and heart valve calcifications in hemodialysis patients-Interrelationship and clinical impact

INTRODUCTION

Arterial calcification is an integral component of active atherosclerosis and is an independent risk factor for cardiovascular disease. Atherosclerosis is a systemic, life-threating disease that may occur at different sites and in various clinical presentations. Intracranial and valvular calcifications are common among dialysis patients and have been associated with poor cardiovascular outcomes. The aim of this study was to assess the clinical impact of valvular and intracranial arterial calcifications on mortality among chronic hemodialysis patients.

METHODS

A blinded neuroradiologist graded intracranial calcifications (ICC) of all hemodialysis patients who underwent brain computerized tomography (CT) from 2015 to 2017 in our institution. Valvular calcifications were assessed by echocardiography. Only hemodialysis patients with available echocardiography and brain CT were included.

FINDINGS

This study included 119 patients (mean age 70.6 ± 12.6 years, 57.1% men, and mean dialysis vintage 25.8 ± 42.6 months). Among the cohort, 19 (16%) had no cardiac or brain calcifications and 65 (54.6%) had both valvular and intracranial calcifications. Considering the patients with no calcification as the reference group yielded adjusted odds ratios for all-cause mortality of 3.68 (95%CI 1.55-8.75) among patients with any brain calcifications, p = 0.002. While valvular calcifications alone did not increase the 1-year mortality rate, ICC was the most important predictor of all-cause 1-year mortality in the study cohort.

DISCUSSION

We found an independent association between ICC and the risk of death among hemodialysis patients. Assessing ICC may contribute to the risk stratification of hemodialysis patients. These calcifications are no less important than valvular calcifications.

Menaquinone-7 ameliorates cerebrovascular calcification-associated memory decline in aged mice

Menaquinone (MK)-7 is a vitamin K2 analog that functions as a cofactor of γ-glutamyl carboxylase involved in the activation of vitamin K (VK)-dependent proteins. The present study aimed to evaluate the effect of MK-7 on memory and cognitive function in aged C57BL/6 mice. Eighteen-month-old mice were raised for a further 4 months, fed on a standard or calcium-rich diet (3 % [w/w]), and were orally given MK-7 (40 and 400 μg/day/mouse) five times per week during the same period. The Morris water maze (MWM) test was performed at 19 and 22 months. The aged mice showed noticeable memory declines in the MWM test at all time points compared with 6-week-old mice, and this memory loss was significantly restored by the daily administration of high-dose MK-7 for 4 months. MK-7 administration also improved micro-computed tomography-based cerebrovascular calcification and aging-associated declines in growth arrest-specific 6, total and carboxylated matrix Gla proteins, and ganglioside levels in the brain of aged mice. It serologically reduced phosphorous levels in the blood, but not the urea, cholesterol, and calcium. Taken together, the long-term administration of MK-7 significantly improved age-related memory and cognitive impairments, possibly through inhibition of cerebrovascular calcification in aged mice, indicating that it can be used to develop new drugs for improving memory and cognitive function in older adults.

Cognitive Sequelae and Hippocampal Dysfunction in Chronic Kidney Disease following 5/6 Nephrectomy

Neurological disorders are prevalent in patients with chronic kidney disease (CKD). Vascular factors and uremic toxins are involved with cognitive impairment in CKD. In addition, vascular dementia-induced alterations in the structure and function of the hippocampus can lead to deficits in hippocampal synaptic plasticity and cognitive function. However, regardless of this clinical evidence, the pathophysiology of cognitive impairment in patients with CKD is not fully understood. We used male Sprague Dawley rats and performed 5/6 nephrectomy to observe the changes in behavior, field excitatory postsynaptic potential, and immunostaining of the hippocampus following CKD progression. We measured the hippocampus volume on magnetic resonance imaging scans in the controls (n = 34) and end-stage renal disease (ESRD) hemodialysis patients (n = 42). In four cognition-related behavior assays, including novel object recognition, Y-maze, Barnes maze, and classical contextual fear conditioning, we identified deficits in spatial working memory, learning and memory, and contextual memory, as well as the ability to distinguish familiar and new objects, in the rats with CKD. Immunohistochemical staining of Na⁺/H⁺ exchanger1 was increased in the hippocampus of the CKD rat models. We performed double immunofluorescent staining for aquaporin-4 and glial fibrillary acidic protein and then verified the high coexpression in the hippocampus of the CKD rat model. Furthermore, results from recoding of the field excitatory postsynaptic potential (fEPSP) in the hippocampus showed the reduced amplitude and slope of fEPSP in the CKD rats. ESRD patients with cognitive impairment showed a significant decrease in the hippocampus volume compared with ESRD patients without cognitive impairment or the controls. Our findings suggest that uremia resulting from decreased kidney function may cause the destruction of the blood–brain barrier and hippocampus-related cognitive impairment in CKD.

Cognition in chronic kidney disease patients: Evaluation with the Beijing version of the Montreal Cognitive Assessment

Patients with chronic kidney disease (CKD) may undergo cognitive impairment. We aimed to explore the cognition of patients with cognitive impairment (CI) and no cognitive impairment (NCI) respectively and the effect of demographics, estimated glomerular filtration rate (eGFR), number of comorbidities (NCD), and hemoglobin on CI in Chinese patients with CKD at stage 3-5 treated by nondialysis by using the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ). A total of 120 patients with CKD were recruited from the Department of Nephrology at the Affiliated Hospital of Nanjing University of Chinese Medicine at in-patient and out-patient follow up. A logistic regression model was performed to assess the effect of these variables on CI of CKD patients. The results indicated that the CI group was mainly in the decline of visuospatial and executive function, abstraction, and memory, compared with the NCI group. In addition, years of education, eGFR and NCD were found as predictors of CI of CKD patients at stage 3-5. Specifically, lower eGFR, less years of education and more comorbidities were risk predictors of CI.

Emerging cross-talks between chronic kidney disease-mineral and bone disorder (CKD-MBD) and malnutrition-inflammation complex syndrome (MICS) in patients receiving dialysis

Chronic kidney disease–mineral and bone disorder (CKD–MBD) is a systemic disorder that affects multiple organs and systems and increases the risk of morbidity and mortality in patients with CKD, especially those receiving dialysis therapy. CKD–MBD is highly prevalent in CKD patients, and its treatment is gaining attention from healthcare providers who manage these patients. Additional important pathologies often observed in CKD patients are chronic inflammation and malnutrition/protein-energy wasting (PEW). These two pathologies coexist to form a vicious cycle that accelerates the progression of various other pathologies in CKD patients. This concept is integrated into the term “malnutrition–inflammation–atherosclerosis syndrome” or “malnutrition–inflammation complex syndrome (MICS)”. Recent basic and clinical studies have shown that CKD–MBD directly induces inflammation as well as malnutrition/PEW. Indeed, higher circulating levels of inorganic phosphate, fibroblast growth factor 23, parathyroid hormone, and calciprotein particles, as markers for critical components and effectors of CKD–MBD, were shown to directly induce inflammatory responses, thereby leading to malnutrition/PEW, cardiovascular diseases, and clinically relevant complications. In this short review, we discuss the close interplay between CKD–MBD and MICS and emphasize the significance of simultaneous control of these two seemingly distinct pathologies in patients with CKD, especially those receiving dialysis therapy, for better management of the CKD/hemodialysis population.

Histology-Verified Intracranial Artery Calcification and Its Clinical Relevance With Cerebrovascular Disease

Intracranial artery calcification (IAC) was regarded as a proxy for intracranial atherosclerosis (ICAS). IAC could be easily detected on routine computer tomography (CT), which was neglected by clinicians in the previous years. The evolution of advanced imaging technologies, especially vessel wall scanning using high resolution-magnetic resonance imaging (HR-MRI), has aroused the interest of researchers to further explore the characteristics and clinical impacts of IAC. Recent histological evidence acquired from the human cerebral artery specimens demonstrated that IAC could mainly involve two layers: the intima and the media. Accumulating evidence from histological and clinical imaging studies verified that intimal calcification is more associated with ICAS, while medial calcification, especially the internal elastic lamina, contributes to arterial stiffness rather than ICAS. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the large intracranial arteries, this review aimed to describe the histological and imaging features of two types of IAC, as well as the risk factors, the hemodynamic influences, and other clinical impacts of IAC occurring in intimal or media layers.

Evaluation of Cerebral Blood Flow Using Arterial Spin Labeling in Patients with Chronic Kidney Disease

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