Dementia risk in renal dysfunction: A systematic review and meta-analysis of prospective studies

Association between dementia diagnosis at dialysis initiation and mortality in older patients with end-stage kidney disease in South Korea

BACKGROUND

The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis.

METHODS

We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort.

RESULTS

Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization.

CONCLUSION

A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Quantifying Cognitive Function in Diabetes: Relationships Between AD8 Scores, HbA1c Levels, and Other Diabetic Comorbidities

BACKGROUND/OBJECTIVES

Dementia associated with diabetes mellitus (DM) has been well documented in the literature, but studies utilizing early screening tools to target populations with mild cognitive dysfunction remain limited. This study aimed to investigate early cognitive decline by studying the relationships between "Ascertain Dementia 8" (AD8) questionnaire scores and glycemic control, lipid profiles, estimated glomerular filtration rate (eGFR), and the complications of diabetes.

METHODS

This case-control, cross-sectional, observational study was conducted at a medical center and an affiliated regional hospital in southern Taiwan from 30 June 2021 to 30 June 2023. Patients diagnosed with type 2 diabetes mellitus aged ≥40 years were recruited. Their past medical history, biochemical data, and AD8 score were collected at the same time.

RESULTS

The patients with glycated hemoglobin (HbA1c) levels of ≥7% had a higher risk of cognitive impairment than those with HbA1c levels of <7% (p < 0.001). The participants whose eGFR was <60 mL/min/1.73 m2 had a higher mean AD8 score compared to those with an eGFR of ≥60 mL/min/1.73 m2 (p = 0.008). The patients with a medical history of peripheral artery disease and diabetic neuropathy were also associated with a higher mean AD8 score (p < 0.001 and p = 0.017, respectively).

CONCLUSIONS

By employing the AD8 questionnaire as a sensitive screening tool, our study suggests that early cognitive decline is significantly associated with poorer glycemic control, a lower glomerular filtration rate, peripheral artery disease, and diabetic neuropathy. Early detection of these risk factors may facilitate timely interventions and tailored treatment strategies to treat or prevent cognitive dysfunction.

Establishing a machine learning dementia progression prediction model with multiple integrated data

OBJECTIVE

Dementia is a significant medical and social issue in most developed countries. Practical tools for predicting the progression of degenerative dementia are highly valuable. Machine learning (ML) methods facilitate the construction of effective models using real-world data, which may include missing values and various integrated datasets.

METHOD

This retrospective study analyzed data from 679 patients diagnosed with degenerative dementia at Fu Jen Catholic University Hospital, who were evaluated by neurologists, psychologists and followed for over two years. Predictive variables were categorized into demographic (D), clinical dementia rating (CDR), mini-mental state examination (MMSE), and laboratory data value (LV) groups. These categories were further integrated into three subgroups (D-CDR, D-CDR-MMSE, and D-CDR-MMSE-LV). We utilized the extreme gradient boosting (XGB) model to rank the importance of variables and identify the most effective feature combination via a step-wise approach.

RESULT

The D-CDR-MMSE-LV model combination showed robust performance with an excellent area under the receiver operating characteristic curve (AUC) and the highest sensitivity value (84.66). Employing both demographic and neuropsychiatric variables, our prediction model achieved an AUC of 83.74. By incorporating additional clinical information from laboratory data and applying our proposed feature selection strategy, we constructed a model based on eight variables that achieved an AUC of 85.12 using the XGB technique.

CONCLUSION

We established a machine-learning model to monitor the progression of dementia using a limited, real-world clinical dataset. The XGB technique identified eight critical variables across our integrated datasets, potentially providing clinicians with valuable guidance.

Association of chronic kidney disease with cognitive impairment risk in middle-aged and older adults: the first longitudinal evidence from CHARLS

Previous studies have yielded inconsistent results regarding the association between chronic kidney disease (CKD) and the risk of cognitive impairment (CI). This study aimed to investigate the longitudinal association of CKD with CI risk in the Chinese middle-aged and older population. A total of 16,515 CI-free participants 45 years of age or older including 15,595 without CKD and 920 with CKD were followed from 2011 until 2018 (median [interquartile range]: 7 [5.5-7]) to detect incident CI. Over the follow-up, 648 participants developed CI. Data were analyzed using multi-adjusted Cox proportional hazard regression and Laplace regression. The incidence rate (IR) of CI was significantly higher in individuals with CKD at 11.46 per 1,000 person-years (95% confidence interval [CI], 8.90 to 14.76) than in those without CKD at 6.38 per 1,000 person-years (95% CI, 5.89 to 6.92). Compared to those without CKD, the hazard ratios of those with CKD was 1.56 (95% CI, 1.19 to 2.04) for CI. Participants with CKD in the middle-aged group (45-54 years) exhibited a heightened risk of CI in age-stratified analyses. CKD accelerated the onset of CI by 1.24 years (10th percentile difference [PD]; 95% CI, -2.03 to -0.43, p < 0.01). The findings from this study revealed a significantly increased risk of CI in individuals with CKD, especially in middle-aged population, where the risk appeared to be more pronounced. This observation underscores the importance of early detection and intervention strategies to alleviate the potential cognitive decline associated with CKD.

How to make a shared decision with older persons for end-stage kidney disease treatment: the added value of geronto-nephrology

Improving care for older people with end-stage kidney disease (ESKD) requires the adaptation of standards to meet their needs. This may be complex due to their heterogeneity in terms of multimorbidity, frailty, cognitive decline and healthcare priorities. As benefits and risks are uncertain for these persons, choosing an appropriate treatment is a daily challenge for nephrologists. In this narrative review, we aimed to describe the issues associated with healthcare for older people, with a specific focus on decision-making processes; apply these concepts to the context of ESKD; identify components and modalities of shared decision-making and suggest means to improve care pathways. To this end, we propose a geronto-nephrology dynamic, described here as the necessary collaboration between these specialties. Underscoring gaps in the current evidence in this field led us to suggest priority research orientations.

Identification of common biomarkers in diabetic kidney disease and cognitive dysfunction using machine learning algorithms

Cognitive dysfunction caused by diabetes has become a serious global medical issue. Diabetic kidney disease (DKD) exacerbates cognitive dysfunction in patients, although the precise mechanism behind this remains unclear. Here, we conducted an investigation using RNA sequencing data from the Gene Expression Omnibus (GEO) database. We analyzed the differentially expressed genes in DKD and three types of neurons in the temporal cortex (TC) of diabetic patients with cognitive dysfunction. Through our analysis, we identified a total of 133 differentially expressed genes (DEGs) shared between DKD and TC neurons (62 up-regulated and 71 down-regulated). To identify potential common biomarkers, we employed machine learning algorithms (LASSO and SVM-RFE) and Venn diagram analysis. Ultimately, we identified 8 overlapping marker genes (ZNF564, VPS11, YPEL4, VWA5B1, A2ML1, KRT6A, SEC14L1P1, SH3RF1) as potential biomarkers, which exhibited high sensitivity and specificity in ROC curve analysis. Functional analysis using Gene Ontology (GO) revealed that these genes were primarily enriched in autophagy, ubiquitin/ubiquitin-like protein ligase activity, MAP-kinase scaffold activity, and syntaxin binding. Further enrichment analysis using Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA) indicates that these biomarkers may play a crucial role in the development of cognitive dysfunction and diabetic nephropathy. Building upon these biomarkers, we developed a diagnostic model with a reliable predictive ability for DKD complicated by cognitive dysfunction. To validate the 8 biomarkers, we conducted RT-PCR analysis in the cortex, hippocampus and kidney of animal models. The results demonstrated the up-regulation of SH3RF1 in the cortex, hippocampus and kidney of mice, which was further confirmed by immunofluorescence and Western blot validation. Notably, SH3RF1 is a scaffold protein involved in cell survival in the JNK signaling pathway. Based on these findings, we support that SH3RF1 may be a common gene expression feature that influences DKD and cognitive dysfunction through the apoptotic pathway.

Risk of Dementia and Alzheimer's Disease Associated With Antidiabetics: A Bayesian Network Meta-Analysis

INTRODUCTION

Dementia risk is substantially elevated in patients with diabetes. However, evidence on dementia risk associated with various antidiabetic regimens is still limited. This study aims to comprehensively investigate the risk of dementia and Alzheimer's disease (AD) associated with various antidiabetic classes.

METHODS

Cochrane Central Register of Controlled Trials, Embase, MEDLINE (PubMed), and Scopus were searched from inception to March 2024 (PROSPERO CRD 42022365927). Observational studies investigating dementia and AD incidences after antidiabetic initiation were identified. Bayesian network meta-analysis was performed to determine dementia and AD risks associated with antidiabetics. Preferred Reporting Items for Systematic Reviews-Network Meta-Analyses (PRISMA-NMA) guidelines were followed. Statistical analysis was performed and updated in November 2023 and March 2024, respectively.

RESULTS

A total of 1,565,245 patients from 16 studies were included. Dementia and AD risks were significantly lower with metformin and sodium glucose co-transporter-2 inhibitors (SGLT2i). Metformin displayed the lowest risk of dementia across diverse antidiabetics, whereas α-glucosidase inhibitors demonstrated the highest risk. SGLT2i exhibited the lowest dementia risk across second-line antidiabetics. Dementia risk was significantly higher with dipeptidyl peptidase-4 inhibitor (DPP4i), metformin, sulfonylureas, and thiazolidinediones (TZD) compared to SGLT2i in the elderly (≥75 years). Dementia risk associated with metformin was substantially lower, regardless of diabetic complication status or baseline A1C.

DISCUSSION

Metformin and SGLT2i demonstrated lower dementia risk than other antidiabetic classes. Patient-specific factors may affect this relationship and cautious interpretation is warranted as metformin is typically initiated at an earlier stage with fewer complications. Hence, further large-scaled clinical trials are required.

Association between kidney function and Parkinson's disease risk: a prospective study from the UK Biobank

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative influenced by various clinical factors. The potential relationship between renal function and the risk of PD remains poorly understood. This study aims to explore the association between kidney function and the risk of developing PD.

METHODS

A population-based cohort study was conducted using data from 400,571 UK Biobank participants. Renal function was assessed using the estimated glomerular filtration rate (eGFR), calculated from serum creatinine and cystatin C levels. The association between eGFR levels and PD risk was evaluated using univariate and multivariate Cox regression analyses, Restricted Cubic Spline (RCS) analysis, and Kaplan-Meier analysis. Additionally, a clinical prediction model was developed and its diagnostic accuracy was evaluated using ROC analysis. A heatmap was also constructed to examine the relationship between clinical factors and gray matter volume in various brain regions.

RESULTS

Over a median observation period of 13.8 years, 2740 PD events were recorded. Cox regression and Kaplan-Meier analyses revealed a significant association between decreased eGFR and increased PD risk, particularly in participants with eGFR < 30 ml/min/1.73 m2. This association was confirmed across three adjusted models. RCS analysis demonstrated a nonlinear relationship between decreasing eGFR and increasing PD risk. Furthermore, changes in eGFR were correlated with alterations in subcortical gray matter volume in regions such as the frontal cortex, striatum, and cerebellum. The clinical prediction model showed high diagnostic accuracy with AUC values of 0.776, 0.780, and 0.824 for 4-, 8-, and 16-year predictions, respectively.

CONCLUSION

Renal insufficiency is significantly associated with an increased risk of PD, highlighting the importance of maintaining good kidney function as a potential preventive measure against PD.

Risk of recurrent stroke and dementia following acute stroke by changes in kidney function: results from the Perindopril Protection Against Recurrent Stroke Study

BACKGROUND

Limited data exist on the relationship between declining kidney function and cardiovascular events, dementia, and mortality in patients with a history of stroke.Thus the aims of the study were to investigate functional relationships between dynamic kidney function change and cardiovascular outcomes, and clarify whether adding kidney parameters to conventional cardiovascular risk factors improves model discrimination.

METHODS

Post hoc analysis of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS) clinical trial of blood pressure lowering for the secondary prevention of stroke. We examined the association between dynamic kidney function defined as percentage change (declines of >30%, and >0 to ≤30%, and increases of ≥0 to <30%, and ≥30%) in estimated glomerular filtration rate (eGFR) over 2 years and recurrent stroke, major cardiovascular events, dementia and all-cause death over the next 2 years using Cox proportional hazard models controlling for eGFR at registration and potential confounders. Restricted cubic splines were used to assess the functional relationships. C-statistics and Net Reclassification Improvement (NRI) at 2 years were used to assess model discrimination.

RESULTS

In 4591 patients followed for a mean of approximately 2 years, 254 (5.5%) developed recurrent stroke, 391 (8.5%) had a major cardiovascular event, 221 (4.8%) developed dementia, and 271 (5.9%) died. Reverse J-like or U-like relationships were observed for percent declines in eGFR and outcomes. Using declines in eGFR of >0 to ≤30% as a reference, increased risks were evident for a greater decline (>30%) in relation to recurrent stroke [adjusted hazard ratio 1.85, 95% confidence interval (CI) 1.20-2.85], major cardiovascular event (2.24, 1.62-3.10) and all-cause death (2.09, 1.39-3.15). A larger increase (≥30%) in eGFR was also associated with a greater risk of all-cause death (1.96, 1.14-3.37). Improvements in the C-statistic were found by adding baseline eGFR and percent change compared with a model with conventional cardiovascular risk factors alone, for major cardiovascular events, dementia, and all-cause mortality.

CONCLUSION

Declining kidney function following an incident cerebrovascular event is associated with additional risk of a major cardiovascular events, dementia, and 2-year mortality. However, a large increase in kidney function was also found to be associated with a higher risk of mortality.

Heat-related illness and dementia: a study integrating epidemiological and experimental evidence

BACKGROUND

Heat-related illness (HRI) is commonly considered an acute condition, and its potential long-term consequences are not well understood. We conducted a population-based cohort study and an animal experiment to evaluate whether HRI is associated with dementia later in life.

METHODS

The Taiwan National Health Insurance Research Database was used in the epidemiological study. We identified newly diagnosed HRI patients between 2001 and 2015, but excluded those with any pre-existing dementia, as the study cohort. Through matching by age, sex, and the index date with the study cohort, we selected individuals without HRI and without any pre-existing dementia as a comparison cohort at a 1:4 ratio. We followed each cohort member until the end of 2018 and compared the risk between the two cohorts using Cox proportional hazards regression models. In the animal experiment, we used a rat model to assess cognitive functions and the histopathological changes in the hippocampus after a heat stroke event.

RESULTS

In the epidemiological study, the study cohort consisted of 70,721 HRI patients and the comparison cohort consisted of 282,884 individuals without HRI. After adjusting for potential confounders, the HRI patients had a higher risk of dementia (adjusted hazard ratio [AHR] = 1.24; 95% confidence interval [CI]: 1.19-1.29). Patients with heat stroke had a higher risk of dementia compared with individuals without HRI (AHR = 1.26; 95% CI: 1.18-1.34). In the animal experiment, we found cognitive dysfunction evidenced by animal behavioral tests and observed remarkable neuronal damage, degeneration, apoptosis, and amyloid plaque deposition in the hippocampus after a heat stroke event.

CONCLUSIONS

Our epidemiological study indicated that HRI elevated the risk of dementia. This finding was substantiated by the histopathological features observed in the hippocampus, along with the cognitive impairments detected, in the experimental heat stroke rat model.

Microvascular burden and long-term risk of stroke and dementia in type 2 diabetes mellitus

OBJECTIVE

To examine the associations between microvascular disease (MVD) and risk of stroke, dementia, and their major subtypes among individuals with type 2 diabetes mellitus (T2DM).

METHODS

We included 26,173 participants with T2DM from the UK Biobank who had no known stroke or dementia at baseline. MVD burden was reflected by the presence of retinopathy, peripheral neuropathy, and chronic kidney disease. Cox regression models were used to estimate hazard ratios (HRs) and 95 % confidential intervals (CIs) of stroke and dementia associated with overall MVD burden and individual MVD.

RESULTS

During a median follow-up of 11.5 years, 1103 incident stroke (964 ischemic and 269 hemorrhagic stroke) and 813 incident dementia (312 Alzheimer's disease and 304 vascular dementia) cases were identified. The risk of stroke, dementia, and their major subtypes all increased with an increasing number of MVD (all P-trend <0.001). The adjusted HRs (95 % CIs) comparing three with no MVD were 5.03 (3.16, 8.02) for all stroke, 4.57 (2.75, 7.59) for ischemic stroke, and 6.60 (2.65, 16.43) for hemorrhagic stroke. The corresponding estimates were 4.28 (2.33, 7.86) for all-cause dementia, 6.96 (3.02, 16.01) for Alzheimer's disease, and 3.81 (1.40, 10.42) for vascular dementia. Among the three MVD, chronic kidney disease showed the strongest associations with both stroke subtypes, while peripheral neuropathy was most strongly associated with both dementia subtypes.

CONCLUSIONS

Risk of stroke, dementia, and their major subtypes increased with an increasing number of MVD. The associations of individual MVD with stroke and dementia varied substantially by types of MVD.

Dementia Development during Long-Term Follow-Up after Surgical Aortic Valve Replacement with a Biological Prosthesis in a Geriatric Population

Surgical aortic valve replacement (SAVR) with a biological heart valve prosthesis (BHV) is often used as a treatment in elderly patients with symptomatic aortic valve disease. This age group is also at risk for the development of dementia in the years following SAVR. The research question is "what are the predictors for the development of dementia?". In 1500 patients undergoing SAVR with or without an associated procedure, preoperative (demographic, cardiac and non-cardiac comorbid conditions), perioperative (associated procedures, cross-clamp and cardiopulmonary bypass time) and postoperative 30-day adverse events (bleeding, thromboembolism, heart failure, conduction defects, arrhythmias, delirium, renal and pulmonary complications) were investigated for their effect on the occurrence of dementia by univariate analyses. Significant factors were entered in a multivariate analysis. The sum of the individual follow-up of the patients was 10,182 patient-years, with a mean follow-up of 6.8 years. Data for the development of dementia could be obtained in 1233 of the 1406 patients who left the hospital alive. Dementia during long-term follow-up developed in 216/1233 (17.2%) of the patients at 70 ± 37 months. Development of dementia reduced the mean survival from 123 (119-128) to 109 (102-116) months (p < 0.001). Postoperative delirium was the dominant predictor (OR = 3.55 with a 95%CI of 2.41-4.93; p < 0.00), followed by age > 80 years (2.38; 1.78-3.18; p < 0.001); preoperative atrial fibrillation (1.47; 1.07-2.01; p = 0.018); cardiopulmonary bypass time > 120 min (1.34; 1.02-1.78; p = 0.039) and postoperative thromboembolism (1.94; 1.02-3.70; p = 0.044). Postoperative delirium, as a marker for poor condition, and an age of 80 or more were the dominant predictors.

Correlation between sarcopenia index and cognitive function in older adult women: A cross-sectional study using NHANES data

OBJECTIVES

The Sarcopenia Index (SI) has the potential as a biomarker for sarcopenia, which is characterized by muscle loss. There is a clear association between sarcopenia and cognitive impairment. However, the relationship between SI and cognitive impairment is yet to be fully understood.

METHODS

We employed data extracted from the U.S. National Health and Nutrition Examination Survey (NHANES) spanning the years 1999 to 2002. Our study encompassed individuals aged 65 to 80 who possessed accessible information regarding both SI and cognitive evaluations with a GFR ≥ 90. Cognitive function was assessed using the digit symbol substitution test (DSST). SI was calculated by serum creatinine (mg/dL)/cystatin C (mg/L)*100. Employing multivariate modeling, we estimated the connection between SI and cognitive performance. Furthermore, to enhance the reliability of our data analysis, we categorized SI using tertiles and subsequently calculated the P-value for trend.

RESULTS

After adjustment for potential confounders, we found SI was significantly and positively correlated with cognitive function scores both in older female in the American population [β = 0.160, 95 % confidence interval (CI) 0.050 to 0.271, P = 0.00461]. Similarly, when the total cognitive function score was treated as a categorical variable according to tertiles, higher SI was related to better total cognitive function scores in females [odds ratio (OR) = 3.968, 95 % CI 1.863 to 6.073, P = 0.00025] following adjustment for confounders.

CONCLUSIONS

Higher SI was correlated with a lower prevalence of cognitive impairment among older adult women with normal kidney function.

Menopausal hormone therapy and risk for dementia in women with CKD: A nationwide observational cohort study

AIM

The risk for dementia is increased in postmenopausal women. The incidences of premature menopause and dementia have increased in patients with chronic kidney disease (CKD). The potential benefits of hormone replacement therapy (HRT) on cognitive function may be a more critical issue for patients with CKD.

METHODS

Women aged >40 years with or without HRT were identified using the 2009 National Health Screening Questionnaire. Women who were newly diagnosed with CKD between 2009 and 2013 were enrolled. HRT was used as an exposure variable, and participants were followed from the day CKD was diagnosed to December 2019. The hazard ratio (HR) for dementia was evaluated using Cox proportional hazards regression analysis.

RESULTS

We included 755 426 postmenopausal women with CKD. The median follow-up period was 7.3 (IQR, 5.8-8.7) years. All-cause dementia, Alzheimer's disease, and vascular dementia occurred in 107 848 (14.3%), 87 833 (11.6%), and 10 245 (1.4%) women, respectively. HRT was significantly associated with a lower risk for dementia in the adjusted Cox regression model (all-cause dementia: HR 0.80; 95% confidence interval [CI] 0.78-0.82; p < 0.001; Alzheimer's disease: HR 0.80; 95% CI 0.77-0.82; p < 0.001; vascular dementia: HR 0.80; 95% CI 0.74-0.87; p < 0.001).

CONCLUSIONS

HRT was significantly associated with a lower risk for CKD-related cognitive dysfunction in postmenopausal women. Prospective studies are needed to determine whether HRT lowers the risk for dementia in menopausal women with CKD.

The association between the estimated glomerular filtration rate and cognitive impairment: the Suita Study

This cross-sectional study investigated the association between the estimated glomerular filtration rate (eGFR), a measure of chronic kidney disease (CKD), and cognitive impairment. We used data from 6215 Japanese individuals registered in the Suita Study. Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score of ≤ 26. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of cognitive impairment for eGFR 45-59.9 and < 45 mL/min/1.73 m2 (mild and moderate-to-severe eGFR reductions) compared to eGFR ≥ 60 mL/min/1.73 m2 (normal eGFR). The results showed that both mild and moderate-to-severe eGFR reductions were associated with cognitive impairment: ORs (95% CIs) = 1.49 (1.22-1.83) and 2.35 (1.69-3.26), respectively (p-trend < 0.001). Each increment of eGFR by 10 mL/min/1.73m2 was associated with 4.8% lower odds of cognitive impairment. In conclusion, eGFR reduction was associated with cognitive impairment. Managing CKD is essential for preventing cognitive impairment.

Association between kidney measurements and cognitive performance in patients with ischemic stroke

BACKGROUND

Individuals with chronic kidney disease (CKD) are at a substantially higher risk for stroke, which may predispose individuals to cognitive impairment. However, the association of low estimated glomerular filtration rate (eGFR) and albuminuria with poorer cognitive performance in patients with stroke is not fully understood, and the current evidence for this association is contradictory. Our aim was to retrospectively investigate whether low eGFR and albuminuria, as indicated by the urine albumin-creatinine ratio (UACR), are independently or jointly associated with worse cognitive performance in patients with ischemic stroke.

METHODS

This retrospective study included 608 patients with acute ischemic stroke. Their UACR and eGFR values were obtained from inpatient medical records. Global cognitive function was assessed with the mini-mental state exam (MMSE) and Montreal Cognitive Assessment (MoCA) one month after hospital discharge. The relationship between renal measures and cognitive performance was assessed using univariate and multiple linear regression analyses. Potential confounders included age, gender, BMI, education, diabetes and hypertension history, NIHSS score, smoking and alcohol consumption status, serum total cholesterol, triglyceride, fasting glucose, uric acid, homocysteine, systolic blood pressure, and either eGFR or UACR.

RESULTS

Patients had an average age of 66.6±4.1 years, and 48% were females. Average eGFR and UACR were 88.4±12.9 ml/min/1.73m2 and 83.6±314.2 mg/g, respectively. The number of patients with eGFR ≥90, 60-89, and <60 ml/min/1.73 m2 was 371 (61%), 207 (34%), and 30 (5%), respectively, and the percentage of patients with UACR <30 mg/g, 30-300 mg/g, and >300 mg/g was 56%, 39%, and 5%, respectively. Multivariate adjusted models showed that eGFR was independently associated with MMSE (β = -0.4; 95% CI = -0.5,-0.4; p <0.001) and MoCA (β = -0.6; 95% CI = -0.7,-0.5; p <0.001). However, UACR was not significantly correlated with MMSE or MoCA.

CONCLUSION

In patients with ischemic stroke, reduced eGFR but not albuminuria was associated with lower cognitive performance. These results show that the eGFR decline could be an effective indicator of cognitive impairment after a stroke. Therefore, regular monitoring and early detection of mild renal dysfunction in patients with acute ischemic stroke might be needed.

Role of Anemia in Dementia Risk Among Veterans With Incident CKD

RATIONALE & OBJECTIVE

Although some evidence exists of increased dementia risk from anemia, it is unclear whether this association persists among adults with CKD. Anemia may be a key marker for dementia among adults with CKD, so we evaluated whether anemia is associated with an increased risk of dementia among adults with CKD.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

The study included 620,095 veterans aged≥45 years with incident stage 3 CKD (estimated glomerular filtration rate [eGFR]<60mL/min/1.73m2) between January 2005 and December 2016 in the US Veterans Health Administration system and followed through December 31, 2018, for incident dementia, kidney failure, or death.

EXPOSURE

Anemia was assessed based on the average of hemoglobin levels (g/L) during the 2 years before the date of incident CKD and categorized as normal, mild, or moderate/severe anemia (≥12.0, 11.0-11.9,<11.0g/dL, respectively, for women, and≥13.0, 11.0-12.9,<11.0g/dL for men).

OUTCOME

Dementia and the composite outcome of kidney failure or death.

ANALYTICAL APPROACH

Adjusted cause-specific hazard ratios were estimated for each outcome.

RESULTS

At the time of incident CKD, the mean age of the participants was 72 years, 97% were male, and their mean eGFR was 51mL/min per 1.73m2. Over a median 4.1 years of follow-up, 92,306 veterans (15%) developed dementia before kidney failure or death. Compared with the veterans with CKD without anemia, the multivariable-adjusted models showed a 16% (95% CI, 14%-17%) significantly higher risk of dementia for those with mild anemia and a 27% (95% CI, 23%-31%) higher risk with moderate/severe anemia. Combined risk of kidney failure or death was higher at 39% (95% CI, 37%-40%) and 115% (95% CI, 112%-119%) for mild and moderate/severe anemia, respectively, compared with no anemia.

LIMITATIONS

Residual confounding from the observational study design. Findings may not be generalizable to the broader US population.

CONCLUSIONS

Anemia was significantly associated with an increased risk of dementia among veterans with incident CKD, underscoring the role of anemia as a predictor of dementia risk.

PLAIN-LANGUAGE SUMMARY

Adults with chronic kidney disease (CKD) often have anemia. Prior studies among adults in the general population suggest anemia is a risk factor for dementia, though it is unclear whether this association persists among adults with CKD. In this large study of veterans in the United States, we studied the association between anemia and the risk of 2 important outcomes in this population: (1) dementia and (2) kidney failure or death. We found that anemia was associated with a greater risk of dementia as well as risk of kidney failure or death. The study findings therefore emphasize the role of anemia as a key predictor of dementia risk among adults with CKD.

Mass Spectrometric Analysis of Urinary N-Glycosylation Changes in Patients with Parkinson's Disease

Urine is thought to provide earlier and more sensitive molecular changes for biomarker discovery than blood. Numerous glycoproteins, peptides, and free glycans are present in urine through glomerular filtration of plasma, cell shedding, apoptosis, proteolytic cleavage, and exosome secretion. Urine biomarkers have enormous diagnostic potential, and the use of these biomarkers is a long-standing practice. The discovery of non-urological disease biomarkers from urine is also gaining attention due to its non-invasive sample collection and ease of analysis. Abnormal protein glycosylation in plasma or cerebrospinal fluid has been associated with Parkinson's disease, however, whether urine with Parkinson's disease has characteristic glycosylation remains to be explored. Here, we use mass spectrometry-based glycomics and glycoproteomics approaches to analyze urine samples for glycans, glycosites, and intact glycopeptides of urine samples. Reduced abundance of N-glycans was detected at the level of total glycans as well as specific glycosites of glycopeptides. The most abundant N-glycan in urine is S(6)1H5N4F1; S(6)2H5N4 and N4H4F1 are highly present in serum and urine, and 10 biantennary galactosylated N-glycans in the urine of PD patients were significantly decreased. The downregulation of sialylation may be due to the reduction of ST3GAL2. Site-specific N-glycosylation analysis revealed that AMBP, UMOD, and RNase1 have PD-specific N-glycosylation sites. GO and KEGG analysis revealed that N-glycosylation changes may provide clues to identify disease-specific glycosylation biomarkers in Parkinson's disease.

Advances in Amyloid-β Clearance in the Brain and Periphery: Implications for Neurodegenerative Diseases

This review examines the role of impaired amyloid-β clearance in the accumulation of amyloid-β in the brain and the periphery, which is closely associated with Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). The molecular mechanism underlying amyloid-β accumulation is largely unknown, but recent evidence suggests that impaired amyloid-β clearance plays a critical role in its accumulation. The review provides an overview of recent research and proposes strategies for efficient amyloid-β clearance in both the brain and periphery. The clearance of amyloid-β can occur through enzymatic or non-enzymatic pathways in the brain, including neuronal and glial cells, blood-brain barrier, interstitial fluid bulk flow, perivascular drainage, and cerebrospinal fluid absorption-mediated pathways. In the periphery, various mechanisms, including peripheral organs, immunomodulation/immune cells, enzymes, amyloid-β-binding proteins, and amyloid-β-binding cells, are involved in amyloid-β clearance. Although recent findings have shed light on amyloid-β clearance in both regions, opportunities remain in areas where limited data is available. Therefore, future strategies that enhance amyloid-β clearance in the brain and/or periphery, either through central or peripheral clearance approaches or in combination, are highly encouraged. These strategies will provide new insight into the disease pathogenesis at the molecular level and explore new targets for inhibiting amyloid-β deposition, which is central to the pathogenesis of sporadic AD (amyloid-β in parenchyma) and CAA (amyloid-β in blood vessels).

Kidney function, albuminuria, and their modification by genetic factors and risk of incident dementia in UK Biobank

BACKGROUND

Associations between kidney function and dementia risk are inconclusive. Chronic kidney disease (CKD) severity is determined by levels of both estimated glomerular filtration rate (eGFR) and the urine albumin to creatinine ratio (ACR). However, whether there is a graded increase in dementia risk for worse eGFR in each ACR category is unclear. Also, whether genetic risk for dementia impacts the associations is unknown. The current study aims to investigate the associations between eGFR and albuminuria with dementia risk both individually and jointly, whether the associations vary by different follow-up periods, and whether genetic factors modified the associations.

METHODS

In 202,702 participants aged ≥ 60 years from the UK Biobank, Cox proportional-hazards models were used to examine the associations between eGFR and urine albumin creatinine ratio (ACR) with risk of incident dementia. GFR was estimated based on serum creatinine, cystatin C, or both. The models were restricted to different follow-up periods (< 5 years, 5-10 years, and ≥ 10 years) to investigate potential reverse causation.

RESULTS

Over 15 years of follow-up, 6,042 participants developed dementia. Decreased kidney function (eGFR < 60 ml/min/1.73m2) was associated with an increased risk of dementia (Hazard Ratio [HR] = 1.42, 95% Confidence Interval [CI] 1.28-1.58), compared to normal kidney function (≥ 90 ml/min/1.73m2). The strength of the association remained consistent when the models were restricted to different periods of follow-up. The HRs for incident dementia were 1.16 (95% CI 1.07-1.26) and 2.24 (95% CI 1.79-2.80) for moderate (3-30 mg/mmol) and severely increased ACR (≥ 30 mg/mmol) compared to normal ACR (< 3 mg/mmol). Dose-response associations were observed when combining eGFR and ACR, with those in the severest eGFR and ACR group having the greatest risk of dementia (HR = 4.70, 95% CI 2.34-9.43). APOE status significantly modified the association (p = 0.04), with stronger associations observed among participants with a lower genetic risk of dementia. There was no evidence of an interaction between kidney function and non-APOE polygenic risk of dementia with dementia risk (p = 0.42).

CONCLUSIONS

Kidney dysfunction and albuminuria were individually and jointly associated with higher dementia risk. The associations were greater amongst participants with a lower genetic risk of dementia based on APOE, but not non-APOE polygenic risk.

The Protective Effect of Vitamin D on Dementia Risk in Hemodialysis Patients

BACKGROUND

Patients with end-stage renal disease (ESRD) undergoing hemodialysis are at an elevated risk of developing dementia, potentially linked to the high prevalence of vitamin D deficiency in this population, which may contribute to cognitive impairment. Nevertheless, the impact of vitamin D supplementation on the risk of dementia in hemodialysis patients remains uncertain, necessitating further investigation to elucidate the potential benefits of vitamin D intervention in this vulnerable group.

METHODS

In this propensity-score-matched comparative cohort study, we sought to assess the impact of vitamin D supplementation on the occurrence of dementia in patients with end-stage renal disease (ESRD) undergoing hemodialysis. A total of 1424 patients were included and matched 1:1 using propensity scores. The study population was divided into two groups: those receiving vitamin D supplementation at a dose of ≥70 μg/week and those without any supplementation. The primary outcome of interest was the incidence of dementia. We calculated adjusted hazard ratios (aHRs) to examine the association between vitamin D supplementation and the risk of dementia while controlling for relevant covariates.

RESULTS

The adjusted hazard ratio (aHR) comparing vitamin D supplementation to no supplementation was 0.44 (95% CI 0.29-0.69; p < 0.0001), demonstrating a significant decrease in the risk of dementia associated with vitamin D supplementation. The aHRs for vitamin D supplementation at different dose ranges (70-105, 106-350, 351-1000, and >1000 μg/week) were 0.51, 0.49, 0.43, and 0.41, respectively (p for trend < 0.0001). These findings suggest a potential dose-dependent relationship between vitamin D supplementation and the reduction of dementia risk.

CONCLUSIONS

In our study, we found that vitamin D supplementation at doses of ≥70 μg/week significantly reduced the risk of dementia in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Furthermore, our results indicated a dose-dependent effect, with higher doses of supplementation correlating with a greater reduction in dementia risk. These findings underscore the potential of vitamin D supplementation as a preventive approach for cognitive impairment in this high-risk population.

Associations between social health factors, cognitive activity and neurostructural markers for brain health - A systematic literature review and meta-analysis

Social health factors (e.g., social activities or social support) and cognitive activity engagement have been associated with dementia risk, but their neural substrates have not been well established. This systematic review and meta-analysis summarizes the available evidence regarding the association between these factors and cerebral macro- and micro-structure. A comprehensive literature search was conducted in various databases, following predefined criteria. Heterogeneity, risk of publication bias and overall certainty of evidence were assessed using standardized scales and, whenever appropriate, random effects meta-analysis was conducted. Of 6715 identified articles, 43 were included. Overall, consistency of findings was low and methodological heterogeneity high for all outcomes. However, in some studies cognitive and social activities were positively associated with total brain, global and cortical grey matter and hippocampal volume as well as white matter microstructural integrity. Furthermore, structural social network characteristics (e.g., social network size) were associated with regional grey matter volumes, while functional social network characteristics (e.g., social support) were additionally associated with total brain volume. Meta-analyses revealed small but significant partial correlations between cognitive and social activities and hippocampal (three studies; n = 892; rz =0.07) and white matter hyperintensity volume (three studies; n = 2934; rz =-0.04). More prospective studies are needed to assess temporal associations.

Primary care biomarkers and dementia in people of the Torres Strait, Australia: extended data analysis

Objective

Dementia disproportionately affects First Nations populations. Biomarkers collected in primary care may assist with determining dementia risk. Our previous underpowered study showed some suggestive associations between baseline biomarkers with follow-up dementia or cognitive impairment. The current study extended this work with a larger linked dataset.

Study design and setting

Probabilistic data linkage was used to combine four baseline datasets with one follow-up assessment of dementia status 0-20 years later in a First Nations population in Australia. Mixed Effects Generalized Linear Regression models were used to test associations between baseline measures and follow-up status, accounting for repeated measures within individuals.

Results

Linked data were available for 88 individuals, with 101-279 baseline observations, depending on the type of measure. Higher urinary albumin to creatine ratio was associated with greater risk of cognitive impairment/dementia, whereas body weight and key lipid markers were negatively associated. There was no clear trend when these associations were examined by timing of measurement (i.e., ≤10 years or >10 years before a dementia assessment).

Conclusions

The results of this study support findings from our previous work and indicate that microalbuminuria can be an early indicator of dementia risk in this population. The weight and lipid profile findings reflect the mixed results in the published literature and require further investigation and interpretation.

Machine Learning-Based Routine Laboratory Tests Predict One-Year Cognitive and Functional Decline in a Population Aged 75+ Years

BACKGROUND

Cognitive and functional decline are common problems in older adults, especially in those 75+ years old. Currently, there is no specific plasma biomarker able to predict this decline in healthy old-age people. Machine learning (ML) is a subarea of artificial intelligence (AI), which can be used to predict outcomes Aim: This study aimed to evaluate routine laboratory variables able to predict cognitive and functional impairment, using ML algorithms, in a cohort aged 75+ years, in a one-year follow-up study.

METHOD

One hundred and thirty-two older adults aged 75+ years were selected through a community-health public program or from long-term-care institutions. Their functional and cognitive performances were evaluated at baseline and one year later using a functional activities questionnaire, Mini-Mental State Examination, and the Brief Cognitive Screening Battery. Routine laboratory tests were performed at baseline. ML algorithms-random forest, support vector machine (SVM), and XGBoost-were applied in order to describe the best model able to predict cognitive and functional decline using routine tests as features.

RESULTS

The random forest model showed better accuracy than other algorithms and included triglycerides, glucose, hematocrit, red cell distribution width (RDW), albumin, hemoglobin, globulin, high-density lipoprotein cholesterol (HDL-c), thyroid-stimulating hormone (TSH), creatinine, lymphocyte, erythrocyte, platelet/leucocyte (PLR), and neutrophil/leucocyte (NLR) ratios, and alanine transaminase (ALT), leukocyte, low-density lipoprotein cholesterol (LDL-c), cortisol, gamma-glutamyl transferase (GGT), and eosinophil as features to predict cognitive decline (accuracy = 0.79). For functional decline, the most important features were platelet, PLR and NLR, hemoglobin, globulin, cortisol, RDW, glucose, basophil, B12 vitamin, creatinine, GGT, ALT, aspartate transferase (AST), eosinophil, hematocrit, erythrocyte, triglycerides, HDL-c, and monocyte (accuracy = 0.92).

CONCLUSIONS

Routine laboratory variables could be applied to predict cognitive and functional decline in oldest-old populations using ML algorithms.

Current progress of cerebral organoids for modeling Alzheimer's disease origins and mechanisms

Alzheimer's disease (AD) is a progressive, neurodegenerative disease that has emerged as a leading risk factor for dementia associated with increasing age. Two-dimensional (2D) cell culture and animal models, which have been used to analyze AD pathology and search for effective treatments for decades, have significantly contributed to our understanding of the mechanism of AD. Despite their successes, 2D and animal models can only capture a fraction of AD mechanisms due to their inability to recapitulate human brain-specific tissue structure, function, and cellular diversity. Recently, the emergence of three-dimensional (3D) cerebral organoids using tissue engineering and induced pluripotent stem cell technology has paved the way to develop models that resemble features of human brain tissue more accurately in comparison to prior models. In this review, we focus on summarizing key research strategies for engineering in vitro 3D human brain-specific models, major discoveries from using AD cerebral organoids, and its future perspectives.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Data-driven health deficit assessment improves a frailty index's prediction of current cognitive status and future conversion to dementia: results from ADNI

Frailty is a dementia risk factor commonly measured by a frailty index (FI). The standard procedure for creating an FI requires manually selecting health deficit items and lacks criteria for selection optimization. We hypothesized that refining the item selection using data-driven assessment improves sensitivity to cognitive status and future dementia conversion, and compared the predictive value of three FIs: a standard 93-item FI was created after selecting health deficit items according to standard criteria (FIs) from the ADNI database. A refined FI (FIr) was calculated by using a subset of items, identified using factor analysis of mixed data (FAMD)-based cluster analysis. We developed both FIs for the ADNI1 cohort (n = 819). We also calculated another standard FI (FIc) developed by Canevelli and coworkers. Results were validated in an external sample by pooling ADNI2 and ADNI-GO cohorts (n = 815). Cluster analysis yielded two clusters of subjects, which significantly (pFDR < .05) differed on 26 health items, which were used to compute FIr. The data-driven subset of items included in FIr covered a range of systems and included well-known frailty components, e.g., gait alterations and low energy. In prediction analyses, FIr outperformed FIs and FIc in terms of baseline cognition and future dementia conversion in the training and validation cohorts. In conclusion, the data show that data-driven health deficit assessment improves an FI's prediction of current cognitive status and future dementia, and suggest that the standard FI procedure needs to be refined when used for dementia risk assessment purposes.

Cognitive performance is associated with glomerular filtration rate in patients with chronic kidney disease: results from the CKD-REIN cohort

BACKGROUND

Chronic kidney disease (CKD) is associated with cognitive impairment in general population. We assessed the association between kidney and cognitive functions in patients with CKD and the influence of cardiovascular (CV) risk factors, and depression on this association.

METHODS

The CKD-Renal Epidemiology and Information Network cohort included 3033 patients with CKD stages 3-4, followed for 5 years. Cognitive function was assessed with the Mini-Mental State Examination (MMSE) and estimated glomerular filtration rate (eGFR) with the CKD-Epidemiology Collaboration equation-creatinin formula. Evolution of the MMSE score over time and its association with baseline eGFR were investigated with linear mixed models. We assessed the risk of incident cognitive outcome (hospitalisation or death with relevant International Classification of Disease-10 codes), with a Cox proportional hazard model.

RESULTS

The mean age was 66.8, the mean eGFR was 33 mL/min/1.73 m² and 387 patients (13.0%) had an MMSE score below 24 at baseline. A 10 mL/min/1.73 m² decrement of baseline eGFR was associated with a mean MMSE decrease of 0.12 (95% CI 0.04 to 0.19) after adjustment for demographic characteristics, depression, CV risk factors and disease; but baseline eGFR was not associated with MMSE temporal evolution. HR for cognitive outcome during follow-up (median 2.01 years) associated with a 10 mL/min/1.73 m² decrement of baseline eGFR was 1.35 (1.07, 1.70) (p=0.01) after adjustment.

CONCLUSIONS

In patients with CKD, lower eGFR was associated with worse cognitive performance and incident cognitive events, independently of demographics, CV risk factors and depression.

TRIAL REGISTRATION NUMBER

NCT03381950.

Association between Kidney Function and the Burden of Cerebral Small Vessel Disease: An Updated Meta-Analysis and Systematic Review

INTRODUCTION

Due to anatomical and functional similarities in microvascular beds, the brain and kidney share distinctive susceptibilities to vascular injury and common risk factors of small vessel disease. The aim of this updated meta-analysis is to explore the association between kidney function and the burden of cerebral small vessel disease (CSVD).

METHODS

PubMed, EMBASE, and Cochrane Library were systematically searched for observational studies that explored the association between the indicators of kidney function and CSVD neuroimaging markers. The highest-adjusted risk estimates and their 95% confidence intervals (CIs) were aggregated using random-effect models.

RESULTS

Twelve longitudinal studies and 51 cross-sectional studies with 57,030 subjects met the inclusion criteria of systematic review, of which 52 were included in quantitative synthesis. According to the pooled results, we found that low estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m2) was associated with cerebral microbleeds (odds ratio (OR) = 1.55, 95% CI = 1.26-1.90), white matter hyperintensities (OR = 1.40, 95% CI = 1.05-1.86), and lacunar infarctions (OR = 1.50, 95% CI = 1.18-1.92), but not with severe perivascular spaces (OR = 1.20, 95% CI = 0.77-1.88). Likewise, patients with proteinuria (OR = 1.75, 95% CI = 1.47-2.09) or elevated serum cystatin C (OR = 1.51, 95% CI = 1.25-1.83) also had an increased risk of CSVD.

CONCLUSION

The association between kidney function and CSVD has been comprehensively updated through this study, that kidney insufficiency manifested as low eGFR, proteinuria, and elevated serum cystatin C was independently associated with CSVD burden.

The Association of Kidney Function with Plasma Amyloid-β Levels and Brain Amyloid Deposition

BACKGROUND

Reduced kidney function is related to brain atrophy and higher risk of dementia. It is not known whether kidney impairment is associated with higher levels of circulating amyloid-β and brain amyloid-β deposition, which could contribute to elevated risk of dementia.

OBJECTIVE

To investigate whether kidney impairment is associated with higher levels of circulating amyloid-β and brain amyloid-β deposition.

METHODS

This cross-sectional study was performed within the community-based Atherosclerosis Risk in Communities (ARIC) Study cohort. We used estimated glomerular filtration rate (eGFR) based on serum creatinine and cystatin C levels and urine albumin-to-creatinine ratio (ACR) to assess kidney function. Amyloid positivity was defined as a standardized uptake value ratios > 1.2 measured with florbetapir positron emission tomography (PET) (n = 340). Plasma amyloid-β1 - 40 and amyloid-β1 - 42 were measured using a fluorimetric bead-based immunoassay (n = 2,569).

RESULTS

Independent of demographic and cardiovascular risk factors, a doubling of ACR was associated with 1.10 (95% CI: 1.01,1.20) higher odds of brain amyloid positivity, but not eGFR (odds ratio per 15 ml/min/1.73 m2 lower eGFR: 1.08; 95% CI: 0.95,1.23). A doubling of ACR was associated with a higher level of plasma amyloid-β1 - 40 (standardized difference: 0.12; 95% CI: 0.09,0.14) and higher plasma amyloid-β1 - 42 (0.08; 95% CI: 0.05,0.10). Lower eGFR was associated with higher plasma amyloid-β1 - 40 (0.36; 95% CI: 0.33,0.39) and higher amyloid-β1 - 42 (0.32; 95% CI: 0.29,0.35).

CONCLUSION

Low clearance of amyloid-β and elevated brain amyloid positivity may link impaired kidney function with elevated risk of dementia. kidney function should be considered in interpreting amyloid biomarker results in clinical and research setting.

Association Between Serum Cystatin C and Cognitive Decline Independently from Creatinine: Evidence from Two Nationally Representative Aging Cohorts

BACKGROUND

Studies on the association between cystatin C based estimated glomerular filtration rate (eGFRcys) and cognitive outcomes yielded inconsistent results.

OBJECTIVE

The present study aimed to examine the potential association of eGFRcys with subsequent cognitive decline rate.

METHODS

A total of 11,503 community-based participants were involved in our analyses, including 5,837 (aged 72.9±6.3; 58.6% women) in the Health and Retirement Study (HRS) from the US and 5,666 (aged 58.1±9.2; 49.0% women) in the China Health and Retirement Longitudinal Study (CHARLS). The association of eGFRcys with subsequent cognitive decline rate was evaluated by linear mixed models.

RESULTS

During 85,266 person-years of follow-up, both baseline elevated serum cystatin C (-0.048 standard deviation [SD]/year per mg/L; 95% confidence interval [CI], -0.060 to -0.036; p < 0.001) and decreased eGFRcys (0.026 SD/year per 30 mL/min/1.73m2; 95% CI, 0.020 to 0.032; p < 0.001) were associated with faster cognitive decline rate after full adjustment. Compared with those had eGFRcys ≥90 mL/min/1.73m2, participants with eGFRcys between 60 to 90 mL/min/1.73m2 (-0.012 SD/year; 95% CI, -0.020 to -0.004; p = 0.004) and those with eGFRcys <60 mL/min/1.73m2 (-0.048 SD/year; 95% CI, -0.058 to -0.039; p < 0.001) experienced statistically significantly faster cognitive decline after adjustment. The associations were independent from serum creatinine/eGFRcre (eGFR that was calculated from serum creatinine).

CONCLUSION

Decreased eGFRcys are significantly associated with faster cognitive decline after full adjustment, independently from serum creatinine/eGFRcre. Serum cystatin C might be a risk factor or a prodromal biomarker of cognitive decline.

Relationship of Kidney Tubule Biomarkers with Cognition among Community-Living Elders in the Health ABC Study

Higher baseline urinary neutrophil gelatinase-associated lipocalin was associated with worse cognitive scores at baseline.Lower concentrations of baseline serum bicarbonate (higher is better) were associated with lower cognitive scores at baseline.We found no associations with urine markers with longitudinal changes in cognition.

Hippocampal Deletion of CB1 Receptor Impairs Social Memory and Leads to Age-Related Changes in the Hippocampus of Adult Mice

Endocannabinoid system activity declines with age in the hippocampus, along with the density of the cannabinoid receptor type-1 (CB1). This process might contribute to brain ageing, as previous studies showed that the constitutive deletion of the CB1 receptor in mice leads to early onset of memory deficits and histological signs of ageing in the hippocampus including enhanced pro-inflammatory glial activity and reduced neurogenesis. Here we asked whether the CB1 receptor exerts its activity locally, directly influencing hippocampal ageing or indirectly, accelerating systemic ageing. Thus, we deleted the CB1 receptor site-specifically in the hippocampus of 2-month-old CB1^flox/flox mice using stereotaxic injections of rAAV-Cre-Venus viruses and assessed their social recognition memory four months later. Mice with hippocampus-specific deletion of the CB1 receptor displayed a memory impairment, similarly as observed in constitutive knockouts at the same age. We next analysed neuroinflammatory changes in the hippocampus, neuronal density and cell proliferation. Site-specific mutant mice had enhanced glial cell activity, up-regulated levels of TNFα in the hippocampus and decreased cell proliferation, specifically in the subgranular zone of the dentate gyrus. Our data indicate that a local activity of the CB1 receptor in the hippocampus is required to maintain neurogenesis and to prevent neuroinflammation and cognitive decline.

Association of kidney function and brain health: A systematic review and meta-analysis of cohort studies

OBJECTIVE

This study aimed to evaluate the bidirectional association between the kidney dysfunction and the brain health, including structural and functional abnormalities.

DESIGN

Systematic review and meta-analysis with network meta-analysis for outcomes with different estimated glomerular filtration rate (eGFR) ranges.

DATA SOURCES

PubMed, Embase database, Cochrane library and Web of Science (up to Dec. 2021).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Longitudinal studies that provided evidence of the impact of kidney function estimated from eGFR and urine albumin-to-creatinine ratio (UACR) or chronic kidney disease (CKD) on structural and functional brain abnormalities, and those that provided evidence of the opposite relationship. Studies with study population mean age under 18 years old were excluded.

MAIN OUTCOME MEASURES

Two independent reviewers screened the included studies, extracted the data, and assessed the risk of bias. We performed a random-effects meta-analysis and a network meta-analysis for outcomes with compatible data. We assessed the risk of bias using the Newcastle-Ottawa Quality Assessment Scale criteria (NOS). Subgroup and sensitivity analyses were conducted to explore heterogeneity in the meta-analyses. Inconsistency analyses using the node-splitting method were performed to confirm the results of network meta-analysis.

RESULTS

A total of 53 studies with 3037,357 participants were included in the current systematic review. Among these, 16 provided evidence of structural brain abnormalities, and 38 provided evidence of cognitive impairment and dementia. Analysis of evidence of categorical kidney function showed a positive association between kidney dysfunction and cerebral small vessel disease (cSVD) (relative risk (RR) 1.77, 95% confidence interval (CI) 1.40-2.24, I² = 0.0%), but such results were not found in the analyses of evidence where the kidney function was measured as a continuous variable. Meanwhile, analysis of 28 prior longitudinal studies with 194 compatible sets of data showed that the worse kidney function as categorical variables was related to a greater risk of global brain cognitive disorder (RR 1.28, 95% CI 1.20-1.36, I² = 82.5%).

CONCLUSIONS

In this systematic review and meta-analysis, we found a positive association between CKD and functional brain disorders. However, the relationship between the kidney dysfunction and structural abnormalities in the brain remains controversial. As for the opposite relationship, structural brain abnormalities, especially cerebral microbleeds and silent infarction, but not functional brain abnormalities, are associated with worse renal function. In addition, a higher UACR, but not a lower eGFR, was associated with a higher risk of Alzheimer's disease and vascular dementia.

Decreased renal function is associated with incident dementia: An IMRD-THIN retrospective cohort study in the UK

INTRODUCTION

Decreased renal function is a potential risk factor for dementia.

METHODS

This retrospective cohort study of 2.8 million adults aged ≥50 years used the IMRD-THIN database, representative of UK primary care, from January 1, 1995 to February 24, 2020. The associations between estimated glomerular filtration rate (eGFR) and urine albumin creatinine ratio (ACR) with incident all-cause dementia were analyzed using Cox regression.

RESULTS

In the eGFR cohort (n = 2,797,384), worsening renal dysfunction was associated with increased hazard of all-cause dementia, with greatest hazard at eGFR 15-30 ml/min/1.73min² (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.19-1.33). In the ACR cohort (n = 641,912), the hazard of dementia increased from ACR 3-30 mg/mmol (HR 1.13, 95% CI 1.10-1.15) to ACR > 30 mg/mmol (HR 1.25, 95% CI 1.18-1.33).

DISCUSSION

Worsening eGFR and albuminuria have graded associations with the risk of dementia, which may have significant implications for the care of patients with kidney disease.

Risk of Dementia after Exposure to Contrast Media: A Nationwide, Population-Based Cohort Study

Contrast-medium-associated kidney injury is caused by the infusion of contrast media. Small vessel disease is significantly associated with various diseases, including simultaneous conditions of the kidney and brain, which are highly vulnerable to similar vascular damage and microvascular pathologies. Data to investigate the adverse effect of contrast media on the brain remain extremely lacking. In this study, 11,332,616 NHI enrollees were selected and divided into two groups, exposed and not exposed to a contrast medium during the observation period, from which 1,461,684 pairs were selected for analyses through matching in terms of age, sex, comorbidities, and frequency of outpatient visits during the previous year. In total, 1,461,684 patients exposed to a contrast medium and 1,461,684 controls not exposed to one were enrolled. In multivariable Cox proportional hazard models, patients exposed to a contrast medium had an overall 2.09-fold higher risk of dementia. In multivariable-stratified analyses, the risk of Alzheimer’s disease was remarkably high in younger patients without any underlying comorbidity. This study is the first to discover that exposure to contrast media is significantly associated with the risk of dementia. A four-fold increased risk of vascular dementia was observed after exposure to a contrast medium. Further studies on the influence of exposure to contrast media on the brain are warranted.

Mild to moderate decrease in eGFR and cognitive decline in older adults

BACKGROUND

Whether mild to moderately low estimated glomerular filtration rate (eGFR) is associated with cognitive decline in older adults is not clear. We evaluated changes in cognition in relation to baseline eGFR in older adults participating in the Alzheimer's Disease Neuroimaging Initiative (ADNI).

METHODS

This is a longitudinal secondary analysis of an established observational cohort. We used data from the ADNI, an National Institutes of Health-funded, multicenter longitudinal observational study that includes participants with and without cognitive impairment who were administered a comprehensive battery of neuropsychological tests every 6 months. We related the Chronic Kidney Disease Epidemiology Collaboration eGFR with previously validated cognition composite scores for memory (ADNI-Mem) and executive function (ADNI-EF) in multivariable linear regression analysis adjusted for age, sex, race and level of education.

RESULTS

A total of 1127 ADNI participants (mean age 74 ± 7 years, 57% men, 97% Caucasian, mean follow-up 6 ± 2.6 years) were included in the analysis. The mean baseline eGFR was 76 ± 19 mL/min/1.73 m2, with 6% with eGFR <45, 22% with eGFR 45-<60, 51% with eGFR 60-90 and 21% with eGFR >90 mL/min/1.73 m2 at baseline. Both ADNI-Mem and ADNI-EF scores declined over time. In the multivariable linear regression model, older age (β = -0.117, P = 0.01), female sex (β = 0.312, P < 0.001) and lower education (β = 0.079, P < 0.001) were associated with a decline in ADNI-Mem scores, whereas baseline eGFR (each 10 mL/min/1.73 m2 change) was not {β = -0.03 [confidence interval (CI) -0.06-0.001], P = 0.11}. Similarly, older age (β = -0.278, P < 0.001) and lower education (β = 0.099, P < 0.001) were associated with a decline in ADNI-EF scores, whereas baseline eGFR was not [β = 0.004 (95% CI -0.04-0.04), P = 0.84].

CONCLUSIONS

In this cohort from the ADNI study, there was no association between baseline eGFR and cognitive decline in older adults with mild to moderately low eGFR.

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.

Blood-brain barrier leakage in Alzheimer's disease: From discovery to clinical relevance

Alzheimer's disease (AD) is the most common form of dementia. AD brain pathology starts decades before the onset of clinical symptoms. One early pathological hallmark is blood-brain barrier dysfunction characterized by barrier leakage and associated with cognitive decline. In this review, we summarize the existing literature on the extent and clinical relevance of barrier leakage in AD. First, we focus on AD animal models and their susceptibility to barrier leakage based on age and genetic background. Second, we re-examine barrier dysfunction in clinical and postmortem studies, summarize changes that lead to barrier leakage in patients and highlight the clinical relevance of barrier leakage in AD. Third, we summarize signaling mechanisms that link barrier leakage to neurodegeneration and cognitive decline in AD. Finally, we discuss clinical relevance and potential therapeutic strategies and provide future perspectives on investigating barrier leakage in AD. Identifying mechanistic steps underlying barrier leakage has the potential to unravel new targets that can be used to develop novel therapeutic strategies to repair barrier leakage and slow cognitive decline in AD and AD-related dementias.

Markers of kidney function, genetic variation related to cognitive function, and cognitive performance in the UK Biobank

BACKGROUND

Chronic kidney disease has been linked to worse cognition. However, this association may be dependent on the marker of kidney function used, and studies assessing modification by genetics are lacking. This study examined associations between multiple measures of kidney function and assessed effect modification by a polygenic score for general cognitive function.

METHODS

In this cross-sectional study of up to 341,208 European ancestry participants from the UK Biobank study, we examined associations between albuminuria and estimated glomerular filtration rate based on creatinine (eGFRcre) or cystatin C (eGFRcys) with cognitive performance on tests of verbal-numeric reasoning, reaction time and visual memory. Adjustment for confounding factors was performed using multivariate regression and propensity-score matching. Interaction between kidney function markers and a polygenic risk score for general cognitive function was also assessed.

RESULTS

Albuminuria was associated with worse performance on tasks of verbal-numeric reasoning (β(points) = -0.09, p < 0.001), reaction time (β(milliseconds) = 7.06, p < 0.001) and visual memory (β(log errors) = 0.013, p = 0.01). A polygenic score for cognitive function modified the association between albuminuria and verbal-numeric reasoning with significantly lower scores in those with albuminuria and a lower polygenic score (p = 0.009). Compared to participants with eGFRcre ≥ 60 ml/min, those with eGFRcre < 60 ml/min had lower verbal-numeric reasoning scores and slower mean reaction times (verbal numeric reasoning β = -0.11, p < 0.001 and reaction time β = 6.08, p < 0.001 for eGFRcre < 60 vs eGFRcre ≥ 60). Associations were stronger using cystatin C-based eGFR than creatinine-based eGFR (verbal numeric reasoning β = -0.21, p < 0.001 and reaction time β = 11.21, p < 0.001 for eGFRcys < 60 vs eGFRcys ≥ 60).

CONCLUSIONS

Increased urine albumin is associated with worse cognition, but this may depend on genetic risk. Cystatin C-based eGFR may better predict cognitive performance than creatinine-based estimates.

Risk and incidence of cognitive impairment in patients with chronic kidney disease and diabetes: the results from a longitudinal study in a community cohort of patients and an age and gender-matched control cohort in North Wales, UK

OBJECTIVES

The aim of the current investigation is to estimate the incidence and risk for neurocognitive disorders (NCD) in a chronic kidney disease (CKD) cohort with diabetes, compared with an age and sex-matched control cohort.

DESIGN

Longitudinal follow-up.

SETTING

District general hospital North Wales, UK.

PARTICIPANTS

Ninety-two patients with CKD and an age and gender-matched sample of 143 controls at baseline and at approximately 36 months.

INTERVENTIONS

Cognitive function was assessed in the patients with CKD (mean age 75.8±9.1; 49 men: 43 women) and the control cohort (mean age 74.4±6.2; 71 men: 72) at baseline and at approximately 36 months. An NCD diagnosis was based on patient, informant, case note review, neuropsychological assessment and application of Diagnostic and Statistical Manual of Mental disorders V.5 (DSM-5) for an NCD and Petersen's criteria for mild cognitive impairment.

RESULTS

Follow-up neuropsychological assessment and application of DSM-5 criteria of the cognitively normal patients and controls revealed, 25/92 (27%) of the CDK and 20/143 (13.9%) in the control cohort developed an NCD. The CKD cohort had a twofold increased risk for the development of an NCD compared with the controls, adjusted for age and sex. The incidence rate for an NCD in the CKD cohort was 10.5 and 5.1 in the controls, respectively. No association was observed with the stage of CKD and cognitive function.

CONCLUSIONS

This longitudinal investigation found that patients with CKD have a twofold increased risk for the development of an NCD. The current investigation highlighted the need to recognise that NCD in patients with CKD is a common comorbidity and that they are at a much higher risk for the development of a significant neurodegenerative disorders. In view of these risks, neuropsychological screening and assessment should be incorporated into normal CKD clinical practice and management.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Association between kidney function and incidence of dementia: 10-year follow-up of the Whitehall II cohort study

BACKGROUND

Cognitive dysfunction is common in haemodialysis patients but whether poor kidney function in the general population is also associated with higher risk of dementia remains unclear.

OBJECTIVE

To examine the association of kidney function with incident dementia in community dwelling older adults.

DESIGN

Whitehall II prospective study.

SETTING

Population-based study on 6,050 adults, mean age 65.8 in 2007-2009.

METHODS

Poor kidney function, defined as estimated Glomerular Filtration Rate (eGFR) <60 ml/min/1.73 m2 in 2007-2009, and adverse change in eGFR was defined as decrease ≥4 ml/min/1.73 m2 between 2007-2009 and 2012-2013.Incident dementia was ascertained through linkage to electronic health records, and Cox regression was used to examine associations with dementia.

RESULTS

A total of 306 cases of dementia were recorded over a mean follow-up of 10 years. Baseline eGFR <60 was associated with a hazard ratio (HR) for dementia of 1.37 (95% CI 1.02, 1.85) in analysis adjusted for sociodemographic factors, hypertension, obesity, stroke, diabetes and cardiovascular disease/medication. Removing stroke cases at baseline and censoring them over the follow-up yielded an HR of 1.42 (95% CI 1.00, 2.00) for the association between CKD and dementia. Decline of eGFR ≥4 between 2007-2009 and 2012-2013 was associated with incidence of dementia over a 6.3 year mean follow-up (HR: 1.37; 95% CI 1.02, 1.85), with somewhat stronger associations when analyses were restricted to those with eGFR ≥60 in 2007-2009 (1.56; 95% CI: 1.12, 2.19).

CONCLUSION

Poor and declining kidney function in older adults is associated with a higher risk of dementia that is not attributable to stroke and persists after accounting for major cardiometabolic conditions.

Characteristics and Outcome Determinants of Hospitalized Older Patients with Cognitive Dysfunction

Cognitive dysfunction commonly occurs among older patients during admission and is associated with adverse prognosis. This study evaluated clinical characteristics and outcome determinants in hospitalized older patients with cognitive disorders. The main outcomes were length of stay, readmission within 30 days, Barthel index (BI) score at discharge, BI score change (discharge BI score minus BI score), and proportion of positive BI score change to indicate change of activities of daily living (ADL) change during hospitalization. A total of 642 inpatients with a mean age of 79.47 years (76–103 years) were categorized into three groups according to the medical history of dementia, and Mini-Mental State Examination (MMSE) scores at admission. Among them, 74 had dementia diagnosis (DD), 310 had cognitive impairment (CI), and 258 had normal MMSE scores. Patients with DD and CI generally had a higher risk of many geriatric syndromes, such as multimorbidities, polypharmacy, delirium, incontinence, visual and auditory impairment, fall history, physical frailty. They had less BI score, BI score change, and proportion of positive BI score change ADL at discharge. (DD 70.0%, CI 79.0%), suggesting less ADL change during hospitalization compared with those with normal MMSE scores (92.9%; p < 0.001). Using multiple regression analysis, we found that among patients with DD and CI, age (p = 0.008) and walking speed (p = 0.023) were predictors of discharge BI score. In addition, age (p = 0.047) and education level were associated with dichotomized BI score change (positive vs. non-positive) during hospitalization. Furthermore, the number and severity of comorbidities predicted LOS (p < 0.001) and readmission (p = 0.001) in patients with cognitive disorders. It is suggested that appropriate strategies are required to improve clinical outcomes in these patients.

Association of Kidney Function with Risk of Incident Dementia: A Prospective Cohort Study of 275,167 UK Biobank Participants

BACKGROUND

Previous studies have reported inconsistent associations between chronic kidney disease (CKD) and dementia.

OBJECTIVE

To evaluate whether CKD is a risk factor for dementia and compare the performance of different measures of calculating estimated glomerular filtration rate (eGFR).

METHODS

275,167 participants from UK Biobank were included and eGFR at baseline was calculated using serum creatinine (eGFRcr), cystatin C (eGFRcys), and creatinine-cystatin C equations (eGFRcr-cys). Restricted cubic splines and Cox regression models were performed to assess the relationship of eGFR with all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD).

RESULTS

We observed a U-shaped relationship between each eGFR and risk of all-cause dementia and VaD, with eGFRcys and eGFRcr-cys showing a closer linkage (peGFRcys <0.0001, peGFRcrhboxcys<0.0001 and peGFRcr = 0.0001). Lower and supranormal eGFR were related to increased risk of all-cause dementia. Compared to the reference category of 90-104 ml/min/1.73 m2, adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause dementia for eGFRcr-cys 30-59, <30, and ≥105 ml/min/1.73 m2 were 1.26 (95% CI [1.05-1.50], p = 0.012), 2.62 (95% CI [1.54-4.47], p < 0.001), and 1.41 (95% CI [1.17-1.70], p < 0.001). No statistically significant association was observed between eGFR with risk of AD.

CONCLUSION

This prospective study identified impaired kidney function as a critical risk factor for dementia and noted the application of cystatin C strengthened the relationship between CKD and dementia, underlining the significant value of preserving kidney function to reduce the risk of dementia and considering cystatin C measurement as part of clinical practice.

Sex differences in predictors for cognitive decline and dementia in people with stroke or transient ischemic attack in the PROGRESS trial

BACKGROUND

Stroke and transient ischemic attack confer greater risk of cognitive decline and dementia.

AIMS

We used data from the Perindopril Protection Against Recurrent Stroke Study (PROGRESS), a blood pressure-lowering randomized controlled trial in stroke/transient ischemic attack. We evaluated overall and sex-specific differences in treatment effects for cognitive decline/dementia, as well as associations with vascular and stroke-specific predictors,considering death as a competing risk.

METHODS

Multinomial logistic regression was used to estimate overall and sex-specific odds ratios (OR) (95% confidence intervals (CI)) for treatment effects and predictors associated with the risk of cognitive decline/dementia, and the women-to-men ratio of odds ratio (RORs).

RESULTS

Over a median four years, 763 cognitive decline/dementia (30.9% women) were recorded in 5888 participants. Women had lower odds of cognitive decline/dementia than men (OR 0.78, 95%CI 0.63-0.95). Active treatment was associated with lower odds of cognitive decline/dementia (0.84, 0.72-0.98), with no evidence of sex difference. Higher education (0.96,0.94-0.98 (per year)) and baseline Mini-Mental State Examination (MMSE)) were associated with lower odds of cognitive decline/dementia (0.84,0.82-0.86 (per point higher)). Higher diastolic blood pressure (1.11,1.02-1.20 (per 10 mmHg)), low estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 (1.27,1.03-1.58), and peripheral arterial disease (1.78,1.26-2.52) were associated with higher odds of cognitive decline/dementia. APOE ɛ4 was not associated with cognitive decline/dementia (1.05 (0.85-1.30)). Low eGFR was more strongly associated with cognitive decline/dementia in women than men (RORs, 1.60 (1.03-2.48)). Diabetes was more strongly associated with men than women.

CONCLUSIONS

Several risk factors were associated with cognitive decline/dementia in people with prior stroke/transient ischemic attack, with notable sex differences. Long-term cognitive sequelae of stroke should be considered to strengthen joint prevention strategies for stroke, cognitive decline, and dementia.Trial Registration: This trial was not registered because enrolment began before 1 July 2005.

Biomarkers of kidney function and cognitive ability: A Mendelian randomization study

BACKGROUND

Estimated glomerular filtration rate (eGFR), albuminuria and serum uric acid (SUA) are markers of kidney function that have been associated with cognitive ability. However, whether these associations are causal is unclear.

METHODS

We performed one-sample Mendelian randomization (MR) to estimate the effects of kidney function markers on cognitive performance using data from the UK Biobank. Polygenic scores for SUA, urine albumin to creatinine ratio (ACR), estimated glomerular filtration rate based on serum creatinine (eGFRcre) and serum cystatin C (eGFRcys) were used as instrumental variables, and cognitive function outcomes included tests of verbal-numeric reasoning, reaction time, visual memory, and numeric memory.

RESULTS

We found no evidence of a causal effect of genetically determined SUA, eGFRcre or eGFRcys on cognitive function outcomes. There was no association between a polygenic score for ACR and verbal-numeric reasoning or numeric memory. However, there was suggestive evidence of a relationship between genetically increased ACR and slower reaction time and worse visual memory. ACR was no longer significantly associated with visual memory in analyses using an unweighted polygenic score and in analyses stratified by sex and age category. Pleiotropy adjusted estimates were directionally consistent with those of the principal analysis but overlapped with the null.

CONCLUSIONS

This MR study does not support causal effects of SUA, eGFRcre or eGFRcys on cognitive performance. Genetically increased ACR was associated with slower processing speed and visual memory, but results need confirmation in independent samples.