Cognitive Impairment in End Stage Renal Disease Patients Undergoing Hemodialysis: Markers and Risk Factors

Exploring the Cognitive Profiles of Haemodialysis Patients using Objective and Subjective Indicators: A Cross-sectional Observational Study

BACKGROUND

Cognitive impairment is common in haemodialysis patients and associated with adverse health outcomes. Previous work focused primarily on neuropsychological tests, the gold standard measure of cognition. However, these tests reflect performance under optimal conditions rather than performance in everyday life. This study aims to assess both objective and subjective cognition in haemodialysis patients.

METHODS

Adult haemodialysis patients completed measures of objective cognitive impairment (Montreal Cognitive Assessment), subjective cognitive complaints, mood and fatigue symptoms, and provided sociodemographic information. Clinical data such as comorbidity were extracted from patients' medical record.

RESULTS

A total of 268 haemodialysis patients (mean age = 59.87 years; 42.5% female) participated. Only 25.0% of the sample had normal cognition, while the rest had either objective cognitive impairments or clinically significant cognitive complaints, or both (both objective impairments and subjective complaints: 26.1%; objective impairments without complaint: 38.4%; significant complaints without objective impairments: 10.4%). Lower education was associated with the presence of objective cognitive impairments, whereas depression was associated with the presence of clinically significant cognitive complaints. Patients who exhibited both objective cognitive impairments and significant cognitive complaints were more likely to have diabetes and higher dialysis dose (Kt/V). Patients with objective cognitive impairments but no significant complaints were significantly older.

CONCLUSIONS

The cognitive burden of haemodialysis patients can be manifested as objective impairments and/or subjective complaints. When combined the two indicators may better represent the overall cognitive well-being in this population. There is a need to screen for cognitive difficulties and develop cognitive rehabilitative strategies in dialysis settings.

Sleep Disorders and Dementia Risk in Older Patients with Kidney Failure: A Retrospective Cohort Study

Key Points

Background

Community-dwelling older adults with sleep disorders are at higher risk of developing dementia. Greater than 50% of older patients with kidney failure experience sleep disorders, which may explain their high burden of dementia.

Methods

Among 216,158 patients (aged 66 years and older) with kidney failure (United States Renal Data System; 2008–2019), we estimated the risk of dementia (including subtypes) associated with sleep disorders using Cox proportional hazards models with propensity score weighting. We tested whether positive airway pressure (PAP) therapy was associated with reduced dementia risk among patients with obstructive sleep apnea (OSA).

Results

26.3% of patients were diagnosed with sleep disorders; these patients had a higher 5-year unadjusted cumulative incidence for any type of dementia (36.2% versus 32.3%; P < 0.001), vascular dementia (4.4% versus 3.7%; P < 0.001), and other/mixed dementia (29.3% versus 25.8%; P < 0.001). Higher risk of any type of dementia was identified in patients with insomnia (adjusted hazard ratio [aHR], 1.42; 95% confidence interval [CI], 1.34 to 1.51), sleep-related breathing disorders (SRBDs) (aHR, 1.20, 95% CI, 1.17 to 1.23), and other sleep disorders (aHR, 1.24; 95% CI, 1.11 to 1.39). Higher vascular dementia risk was observed in patients with insomnia (aHR, 1.43; 95% CI, 1.19 to 1.73) and SRBDs (aHR, 1.15; 95% CI, 1.07 to 1.24). Patients with SRBDs (aHR, 1.07; 95% CI, 1.00 to 1.15) were at higher risk of Alzheimer disease. Among patients with OSA, PAP therapy was associated with lower risk of any type of dementia (aHR, 0.82; 95% CI, 0.76 to 0.90) and vascular dementia (aHR, 0.65; 95% CI, 0.50 to 0.85).

Conclusions

Older patients with kidney failure and sleep disorders are at a higher risk of dementia. Sleep is an important modifiable factor that should be considered for targeted interventions to mitigate dementia risk in patients with kidney failure. For patients with OSA, PAP therapy is associated with lower dementia risk.

End-stage renal disease accompanied by mild cognitive impairment: A study and analysis of trimodal brain network fusion

The function and structure of brain networks (BN) may undergo changes in patients with end-stage renal disease (ESRD), particularly in those accompanied by mild cognitive impairment (ESRDaMCI). Many existing methods for fusing BN focus on extracting interaction features between pairs of network nodes from each mode and combining them. This approach overlooks the correlation between different modal features during feature extraction and the potentially valuable information that may exist between more than two brain regions. To address this issue, we propose a model using a multi-head self-attention mechanism to fuse brain functional networks, white matter structural networks, and gray matter structural networks, which results in the construction of brain fusion networks (FBN). Initially, three networks are constructed: the brain function network, the white matter structure network, and the individual-based gray matter structure network. The multi-head self-attention mechanism is then applied to fuse the three types of networks, generating attention weights that are transformed into an optimized model. The optimized model introduces hypergraph popular regular term and L1 norm regular term, leading to the formation of FBN. Finally, FBN is employed in the diagnosis and prediction of ESRDaMCI to evaluate its classification performance and investigate the correlation between discriminative brain regions and cognitive dysfunction. Experimental results demonstrate that the optimal classification accuracy achieved is 92.80%, which is at least 3.63% higher than the accuracy attained using other methods. This outcome confirms the effectiveness of our proposed method. Additionally, the identification of brain regions significantly associated with scores on the Montreal cognitive assessment scale may shed light on the underlying pathogenesis of ESRDaMCI.

Multiparameter neuroimaging study of neurovascular coupling changes in patients with end-stage renal disease

PURPOSE

To assess changes in neurovascular coupling (NVC) by evaluating the relationship between cerebral perfusion and brain connectivity in patients with end-stage renal disease (ESRD) undergoing hemodialysis versus in healthy control participants. And by exploring brain regions with abnormal NVC associated with cognitive deficits in patients, we aim to provide new insights into potential preventive and therapeutic interventions.

MATERIALS AND METHODS

A total of 45 patients and 40 matched healthy controls were prospectively enrolled in our study. Montreal Cognitive Assessment (MoCA) was used to assess cognitive function. Arterial spin labeling (ASL) was used to calculate cerebral blood flow (CBF), and graph theory-based analysis of results from resting-state functional magnetic resonance imaging (rs-fMRI) was used to calculate brain network topological parameters (node betweenness centrality [BC], node efficiency [Ne], and node degree centrality [DC]). Three NVC biomarkers (CBF-BC, CBF-Ne, and CBF-DC coefficients) at the whole brain level and 3 NVC biomarkers (CBF/BC, CBF/Ne, and CBF/DC ratios) at the local brain region level were used to assess NVC. Mann-Whitney U tests were used to compare the intergroup differences in NVC parameters. Spearman's correlation analysis was used to evaluate the relationship among NVC dysfunctional pattern, cognitive impairment, and clinical characteristics multiple comparisons were corrected using a voxel-wise false-discovery rate (FDR) method (p < .05).

RESULTS

Patients showed significantly reduced global coupling coefficients for CBF-Ne (p = .023) and CBF-BC (p = .035) compared to healthy controls. Coupling ratios at the local brain region level were significantly higher in patients in 33 brain regions (all p values < .05). Coupling ratio changes alone or accompanied by changes in CBF, node properties, or both CBF and node properties were identified. In patients, negative correlations were seen between coupling ratios and MoCA scores in many brain regions, including the left dorsolateral superior frontal gyrus, the bilateral median cingulate and paracingulate gyri, and the right superior parietal gyrus. The correlations remained even after adjusting for hemoglobin and hematocrit levels.

CONCLUSION

Disrupted NVC may be one mechanism underlying cognitive impairment in dialysis patients.

Exploring the unmet needs and experiences of informal caregivers of patients with end-stage kidney disease (ESKD) receiving haemodialysis - a qualitative study

BACKGROUND

Patients with end stage kidney disease (ESKD) receiving haemodialysis experience multiple symptoms, which can present physical and emotional challenges for both patients and their informal caregivers. Caregivers can experience anxiety, depression, and social isolation negatively impacting their overall wellbeing and resulting in caregiver burden. The needs of this group of caregivers have been largely neglected, with little emphasis placed on supportive interventions that might assist and support them in their caring role.

AIM

The aim of this study Is to explore the unmet needs and experiences of caregivers of patients with ESKD receiving haemodialysis, and to determine the components of a supportive intervention.

DESIGN

A qualitative study using semi-structured interviews (n = 24) with informal caregivers. An interpretive qualitative framework was employed to generate a rich understanding of the unmet needs and experiences of caregivers. Data was analysed using thematic analysis. Interviews were transcribed verbatim and data management was assisted through NVIVO version 11.

SETTING/PARTICIPANTS

Twenty-four informal caregivers were purposively recruited from two haemodialysis settings within Northern Ireland.

RESULTS

Three themes were identified: (1) The negative impact of distress, anxiety, and isolation on caregivers due to their caregiving responsibilities (2) Inadequate information and knowledge about the complexities of renal care (3) The benefits of spiritual beliefs, stress management and peer support in relieving the caregiving burden.

CONCLUSIONS

Caregivers of patients with ESKD receiving haemodialysis are at increased risk of physical and psychological distress and burden arising from their caregiving role. The unpredictable nature of ESKD and haemodialysis treatment negatively impacts the caregiver experience and adds to the challenges of the role. The information needs of caregivers are not always adequately met and they subsequently lack appropriate knowledge, skills, and guidance to assist them in their caregiving role. Supportive interventions are essential for caregivers to enhance their capability to deliver effective care and improve their quality of life.

Predictors of cognitive impairment and its association with mortality in maintenance hemodialysis patients: A prospective follow-up study

Objective

To determine predictors of cognitive impairment (CI) and its association with mortality in maintenance haemodialysis (MHD) patients.

Methods

This prospective follow up study was conducted at HD Department, Mayo Hospital, Lahore from September, 2021 to November, 2022. All patients undergoing MHD for more than three months and having age between 18-65 years were included while those with dialysis duration less than three months, history of neuropsychiatric illness was excluded. Cognitive function was assessed using British Columbia Cognitive Complaints Inventory (BC-CCI) questionnaire. CI was defined on Likert scale as mild, moderate, and severe. Patients were followed up to one year regarding outcome measures.

Results

One hundred and four patients were included in the study. Mean age was 45.86±11.11 years and Diabetes Mellitus (DM) was the most common cause of End Stage Renal Disease (ESRD) in 39(37.5%) patients. CI was found in 86(82.7%) patients in following order of severity: mild 61(58.7%), moderate 19(18.3%) and severe 6(5.9%). Increasing age (≥50 years), gender (female), Diabetes Mellitus (DM), unemployment and education <10th grade were found as significant predictors of CI (p<0.05). Significant positive correlations of CI score with age (r=0.338, p<0.001) and MHD duration (r=0.211, p=0.032) were found. However, the CI was not significantly associated with mortality (p=0.302).

Conclusion

CI was common in MHD patients. Factors affecting CI were increasing age, female gender, DM, unemployment and low education level. CI was not associated with mortality in MHD patients.

Integration of temporal & spatial properties of dynamic functional connectivity based on two-directional two-dimensional principal component analysis for disease analysis

Dynamic functional connectivity, derived from resting-state functional magnetic resonance imaging (rs-fMRI), has emerged as a crucial instrument for investigating and supporting the diagnosis of neurological disorders. However, prevalent features of dynamic functional connectivity predominantly capture either temporal or spatial properties, such as mean and global efficiency, neglecting the significant information embedded in the fusion of spatial and temporal attributes. In addition, dynamic functional connectivity suffers from the problem of temporal mismatch, i.e., the functional connectivity of different subjects at the same time point cannot be matched. To address these problems, this article introduces a novel feature extraction framework grounded in two-directional two-dimensional principal component analysis. This framework is designed to extract features that integrate both spatial and temporal properties of dynamic functional connectivity. Additionally, we propose to use Fourier transform to extract temporal-invariance properties contained in dynamic functional connectivity. Experimental findings underscore the superior performance of features extracted by this framework in classification experiments compared to features capturing individual properties.

Role of the Gut Bacteria-Derived Metabolite Phenylacetylglutamine in Health and Diseases

Over the past few decades, it has been well established that gut microbiota-derived metabolites can disrupt gut function, thus resulting in an array of diseases. Notably, phenylacetylglutamine (PAGln), a bacterial derived metabolite, has recently gained attention due to its role in the initiation and progression of cardiovascular and cerebrovascular diseases. This meta-organismal metabolite PAGln is a byproduct of amino acid acetylation of its precursor phenylacetic acid (PAA) from a range of dietary sources like egg, meat, dairy products, etc. The microbiota-dependent metabolism of phenylalanine produces PAA, which is a crucial intermediate that is catalyzed by diverse microbial catalytic pathways. PAA conjugates with glutamine and glycine in the liver and kidney to predominantly form phenylacetylglutamine in humans and phenylacetylglycine in rodents. PAGln is associated with thrombosis as it enhances platelet activation mediated through the GPCRs receptors α2A, α2B, and β2 ADRs, thereby aggravating the pathological conditions. Clinical evidence suggests that elevated levels of PAGln are associated with pathology of cardiovascular, cerebrovascular, and neurological diseases. This Review further consolidates the microbial/biochemical synthesis of PAGln and discusses its role in the above pathophysiologies.

The effect of melatonin on sleep quality and cognitive function of individuals undergoing hemodialysis

BACKGROUND

and purpose: This study aimed to investigate the effect of melatonin on sleep quality and cognitive function of individuals undergoing hemodialysis.

MATERIALS AND METHODS

In this randomized controlled clinical trial, 102 eligible individuals were assigned to two equal intervention and control groups. The intervention group received melatonin 3 mg tablets half an hour before going to bed for six weeks, while the control group was given a placebo with similar conditions.

RESULTS

This study had 102 participants who were divided into intervention and control groups. The mean age of the participants was 58.30 (SD = 12.10). Among the participants, 54.90% were female. Moreover, 33.33% of the individuals received dialysis for four years or longer. After the intervention, the mean and standard deviation of the Pittsburgh Sleep Quality Index (PSQI) was 12.66 (SD = 3.09) in the intervention group and 18.86 (SD = 3.8) in the control group (P < 0.001). Moreover, the mean sleep quality index in the intervention group showed a statistically significant difference before and after the intervention (P < 0.001); the PSQI score declined from 20.21 to 12.66. Likewise, there was a statistically significant difference between the two groups after intervention in the mean Montreal Cognitive Assessment (MoCA) index (P = 0.002); it was 24.27 (SD = 3.42) in the intervention group and 22.15 (SD = 2.3) in the control group. The mean MoCA score in the intervention group showed a significant difference before and after the intervention (P < 0.001), increasing from 21.19 to 24.27.

CONCLUSION

According to the study's findings, melatonin can improve individuals undergoing hemodialysis' cognitive function and sleep quality.

One-year change in sarcopenia was associated with cognitive impairment among haemodialysis patients

BACKGROUND

Our study aimed to evaluate change in sarcopenia, its defining components over 1 year follow-up and investigate associations with subsequent cognitive decline, incident mild cognitive impairment (MCI) and dementia among patients undergoing haemodialysis (HD).

METHODS

In the multicentre, longitudinal study, 1117 HD patients aged 56.8 ± 14.3 years (654 men; and 463 women) from 17 dialysis centres in Guizhou Province, China, were recruited in 2019 and followed up for 1 year in 2020. Sarcopenia was diagnosed with Asian Working Group for Sarcopenia criteria using appendicular skeletal muscle mass index (ASMI) and handgrip strength (HGS). Body composition was measured using body composition monitor; body water, weight, and height were corrected to calculate ASMI. HGS was measured by mechanical handgrip dynamometer. Cognitive function was measured with Mini Mental State Examination. Multivariate linear, logistic regression models and subgroup analyses were employed to examine the associations of changes in sarcopenia, ASMI, and HGS with Mini Mental State Examination score change, and incident MCI, dementia.

RESULTS

Four hundred fourteen (37.1%) patients had sarcopenia at baseline; during 1 year follow-up, 257 (23.0%) developed MCI and 143 (12.8%) developed dementia. According to changes in sarcopenia, patients were stratified into four groups: non-sarcopenia; non-sarcopenia to sarcopenia; sarcopenia; and sarcopenia to non-sarcopenia. HD patients in sarcopenia and non-sarcopenia to sarcopenia groups had higher risk of MCI (34.8%, 32.0%, vs. 17.4%) and dementia (20.6%, 19.8%, vs. 8.7%), compared non-sarcopenia group (P < 0.001). Multivariate linear regression analyses showed that sarcopenia [regression coefficients (β) -1.098, 95% confidence interval (CI) -1.872, -0.324, P = 0.005] and non-sarcopenia to sarcopenia (β -1.826, -2.441, -1.212, P < 0.001) were associated with faster cognitive decline compared to non-sarcopenia. HGS decline (β 0.046, 0.027-0.064, P < 0.001) and ASMI decline (β 0.236, 0.109-0.362, P < 0.001) were both positively associated with cognitive decline. Multivariate logistic regression analyses demonstrated that patients with sarcopenia and non-sarcopenia to sarcopenia were both at increased risk of developing MCI [odds ratio (OR) 1.788, 95% CI 1.115-2.870, P = 0.016 and OR 1.589, 95% CI 1.087-2.324, P = 0.017, respectively], but only non-sarcopenia to sarcopenia was at increased risk of dementia (OR 1.792, 95% CI 1.108-2.879, P = 0.017). Both greater change of ASMI and HGS had lower risk of MCI with adjusted ORs of 0.857 (0.778-0.945, P = 0.002) and 0.976 (0.963-0.989, P < 0.001). Robust associations were found among female individuals, aged >60 years, and with low educational level.

CONCLUSIONS

Longitudinal associations were observed between new-onset, persistent sarcopenia, and cognitive impairment. Early detection and intervention should be implemented to delay the onset of sarcopenia and improve cognitive health among HD patients.

Mental health and its influencing factors of maintenance hemodialysis patients: a semi-structured interview study

BACKGROUND

Maintenance hemodialysis (MHD) is a commonly used renal replacement therapy for end-stage renal disease patients. MHD patients have undergone multiple physiological stressors, which may cause physical problems and affect their mental health; however, few qualitative studies have been done on the mental health of MHD patients. Such qualitative research becomes the basis for further quantitative research and is critical to validating its results. Therefore, the current qualitative study used a semi-structured interview format, and aimed to explore the mental health and its influencing factors of MHD patients who are not receiving intervention treatment to determine how best to ameliorate their mental health.

METHODS

Based on the application of Grounded Theory, semi-structured face-to-face interviews were conducted with 35 MHD patients, following consolidated criteria for reporting qualitative studies (COREQ) guidelines. Two indicators (emotional state and well-being) were used to assess MHD patients' mental health. All interviews were recorded, after which two researchers independently performed data analyses using NVivo.

RESULTS

Acceptance of disease, complications, stress and coping styles, and social support were found to be the influencing factors of MHD patients' mental health. High acceptance of disease, healthy coping styles, and high social support were positively correlated with mental health. In contrast, low acceptance of disease, multiple complications, increased stress, and unhealthy coping styles were negatively correlated with mental health.

CONCLUSION

One's acceptance of the disease played a more significant role than other factors in affecting MHD patients' mental health.

Prevalence of Cognitive Impairment in Peritoneal Dialysis Patients and Associated Factors

BACKGROUND

Cognitive impairment (CI) in patients with chronic kidney disease, including those treated with renal replacement therapy, is a growing problem worldwide.

OBJECTIVES

The study aimed to assess the prevalence of CI and associated factors in patients undergoing peritoneal dialysis (PD).

METHODS

In this cross-sectional study, 18 consecutive patients with PD therapy and 15 controls were evaluated for CI using the Addenbrooke's Cognitive Examination III (ACE III) test.

RESULTS

The prevalence of CI was 33% in patients and 27% in the control group and was not statistically significant. A higher prevalence of CI was found in subjects aged ≥65 years old than in those <65 years old (p = 0.02), but only in the control group. The prevalence of CI in PD patients over and under 65 years of age did not differ statistically significantly (p = 0.12). Memory and verbal fluency were the most affected cognitive domain in PD patients with CI (p = 0.00, p = 0.04, respectively). There was a significant correlation between higher educated PD patients and the ACE III test results. The duration of dialysis did not affect the results of the cognitive screening test.

CONCLUSIONS

CI is a growing problem in the course of chronic kidney disease and dialysis therapy. It seems that cognitive problems may occur in patients undergoing PD at a younger age than in the general population with particularly affected memory and verbal fluency. Higher educated patients score better on the cognitive screening test.

The Influence of Healthy Habits on Cognitive Functions in a Group of Hemodialysis Patients

(1) Background: Cognitive impairment (CI) is more prevalent in hemodialysis (HD) patients than in the general population. The purpose of this study was to examine if behavioral, clinical, and vascular variables are linked with CI in individuals with HD. (2) Methods: Initially, 47 individuals with chronic HD volunteered to participate in the trial, but only 27 patients ultimately completed the Montreal Cognitive Assessment (MoCA) and the Computerized Cognitive Assessment Tool (CompBased-CAT). We collected information on smoking, mental activities, physical activity (Rapid Assessment of Physical Activity, RAPA), and comorbidity. The oxygen saturation (rSO2) and pulse wave velocity (PWV; IEM Mobil-O-Graph) of the frontal lobes were measured. (3) Results: Significant associations were discovered between MoCA and rSO2 (r = 0.44, p = 0.02 and r = 0.62, p = 0.001, right/left, respectively), PWV (r = -0.69, p = 0.0001), CCI (r = 0.59, p = 0.001), and RAPA (r = 0.72, p = 0.0001). Those who actively occupied their time during dialysis and non-smokers achieved higher cognitive exam results. A multivariate regression study demonstrated that physical activity (RAPA) and PWV had separate effects on cognitive performance. (4) Conclusions: Cognitive skills are related to inter-dialysis healthy habits (physical activity, smoking) and intra-dialysis activities (tasks and mind games). Arterial stiffness, oxygenation of the frontal lobes, and CCI were linked with CI.

Healthy aging and chronic kidney disease

The world population is aging and the prevalence of noncommunicable diseases such as diabetes, hypertension, and chronic kidney disease (CKD) will increase significantly. With advances in medical treatment and public health, the human lifespan continues to outpace the health span in such a way that the last decade of life is generally spent in poor health. In 2015, the World Health Organization defined healthy aging as 'the process of developing and maintaining the functional ability that enables wellbeing in older age.' CKD is increasingly being recognized as a model of accelerated aging and is associated with physical performance decline, cognitive decline, falls and fractures, poor quality of life, loss of appetite, and inflammation. Frailty and dementia are the final pathways and key determinants of disability and mortality independent of underlying disease. CKD, dementia, and frailty share a triangular relationship with synergistic actions and have common risk factors wherein CKD accelerates frailty and dementia through mechanisms such as uremic toxicity, metabolic acidosis and derangements, anorexia and malnutrition, dialysis-related hemodynamic instability, and sleep disturbance. Frailty accelerates glomerular filtration decline as well as dialysis induction in CKD and more than doubles the mortality risk. Anorexia is one of the major causes of protein-energy malnutrition, which is also prevalent in the aging population and warrants screening. Healthcare systems across the world need to have a system in place for the prevention of CKD amongst high-risk older adults, focusing on screening for poor prognostic factors amongst patients with CKD such as frailty, poor appetite, and cognitive impairment and providing necessary person-centered interventions to reverse underlying factors that may contribute to poor outcomes.

Phosphate in the Context of Cognitive Impairment and Other Neurological Disorders Occurrence in Chronic Kidney Disease

The nervous system and the kidneys are linked under physiological states to maintain normal body homeostasis. In chronic kidney disease (CKD), damaged kidneys can impair the central nervous system, including cerebrovascular disease and cognitive impairment (CI). Recently, kidney disease has been proposed as a new modifiable risk factor for dementia. It is reported that uremic toxins may have direct neurotoxic (astrocyte activation and neuronal death) and/or indirect action through vascular effects (cerebral endothelial dysfunction, calcification, and inflammation). This review summarizes the evidence from research investigating the pathophysiological effects of phosphate toxicity in the nervous system, raising the question of whether the control of hyperphosphatemia in CKD would lower patients’ risk of developing cognitive impairment and dementia.