Cholesterol and Dementia: A Long and Complicated Relationship

Validation of the brain health index in the European Prevention of Alzheimer's Dementia cohort

Background

Brain Health Index (BHI) assimilates various MRI sequences, giving a quantitative measure of brain health. To date, BHI validation has been cross-sectional and limited to selected populations. Further large-scale validation and assessment of temporal change is required to understand its clinical utility.

Aim

Assess 1) relationships between variables associated with cognitive decline and BHI 2) associations between BHI and measures of cognition and 3) longitudinal changes in BHI and relationship with cognitive function.

Methods

BHI computation involved Gaussian mixture-model cluster analysis of T1, T2, T2*, and T2 FLAIR MRI data from participants within the European Prevention of Alzheimer's Dementia (EPAD) cohort. Group differences (gender- and health-based) were evaluated using independent samples Welch's t-tests. Relationships between BHI, age and cognitive tests used linear regression. Longitudinal analysis (12/24 months) utilised mixed linear regression models to examine BHI changes, and paired BHI/cognition associations.

Results

Data from N = 1496 predominantly Caucasian participants (50-88 years old, 43.32% male) were used. BHI scores were lower in those with diabetes (p < 0.001, d = 0.419), hypertension (p < 0.001, d = 0.375), hypercholesterolemia (p < 0.001, d = 0.193) and stroke (p < 0.05, d = 0.512). APOE was not significantly related to BHI scores. After correction for age, cross-sectional BHI scores were significantly associated with all measures of cognitive function in males, but only the Four Mountains Test (4MT) in females. Longitudinal change in BHI and cognition were not consistently related.

Conclusions

BHI is a valid marker of cognitive decline and relatively stable over 1-2 year follow-up periods. Further work should assess temporal changes over a longer duration and determine relationships between BHI and cognition in more diverse populations.

[Neuropsychological impairments in patients undergoing peritoneal dialysis treatment]

BACKGROUND

Patients with chronic kidney disease on hemodialysis (HD) often have cognitive deficits. However, there are few studies that have examined the neuropsychological impairments of patients receiving peritoneal dialysis (PD).

METHODS

Executive functions, processing speed and verbal memory were assessed in 27 PD patients, 42 HD patients, and 42 healthy participants (HP). Systolic blood pressure and total time on renal replacement therapy (RRT) were controlled statistically. Associations between performance and clinical factors were analyzed using correlations and multiple regression.

RESULTS

The DP group showed better performance compared to the HD group in verbal fluency, working memory, cognitive flexibility, planning and decision making. The DP group showed worse execution than the HP group in verbal inhibition and memory. Executive function scores were positively associated with total months on PD, total months on RRT, total months on HD, albumin, total cholesterol, and phosphorus, and negatively with ferritin.

CONCLUSION

Global executive functioning was more optimal in PD patients than in HD patients. The results show the positive effect of PD on executive functions, which must be taken into account when choosing the TRS. The associations observed between biochemical factors and performance show the importance of maintaining an adequate nutritional status in these patients.

PCSK9 ablation attenuates Aβ pathology, neuroinflammation and cognitive dysfunctions in 5XFAD mice

BACKGROUND

Increasing evidence highlights the importance of novel players in Alzheimer's disease (AD) pathophysiology, including alterations of lipid metabolism and neuroinflammation. Indeed, a potential involvement of Proprotein convertase subtilisin/kexin type 9 (PCSK9) in AD has been recently postulated. Here, we first investigated the effects of PCSK9 on neuroinflammation in vitro. Then, we examined the impact of a genetic ablation of PCSK9 on cognitive performance in a severe mouse model of AD. Finally, in the same animals we evaluated the effect of PCSK9 loss on Aβ pathology, neuroinflammation, and brain lipids.

METHODS

For in vitro studies, U373 human astrocytoma cells were treated with Aβ fibrils and human recombinant PCSK9. mRNA expression of the proinflammatory cytokines and inflammasome-related genes were evaluated by q-PCR, while MCP-1 secretion was measured by ELISA. For in vivo studies, the cognitive performance of a newly generated mouse line - obtained by crossing 5XFADHet with PCSK9KO mice - was tested by the Morris water maze test. After sacrifice, immunohistochemical analyses were performed to evaluate Aβ plaque deposition, distribution and composition, BACE1 immunoreactivity, as well as microglia and astrocyte reactivity. Cholesterol and hydroxysterols levels in mouse brains were quantified by fluorometric and LC-MS/MS analyses, respectively. Statistical comparisons were performed according to one- or two-way ANOVA, two-way repeated measure ANOVA or Chi-square test.

RESULTS

In vitro, PCSK9 significantly increased IL6, IL1B and TNFΑ mRNA levels in Aβ fibrils-treated U373 cells, without influencing inflammasome gene expression, except for an increase in NLRC4 mRNA levels. In vivo, PCSK9 ablation in 5XFAD mice significantly improved the performance at the Morris water maze test; these changes were accompanied by a reduced corticohippocampal Aβ burden without affecting plaque spatial/regional distribution and composition or global BACE1 expression. Furthermore, PCSK9 loss in 5XFAD mice induced decreased microgliosis and astrocyte reactivity in several brain regions. Conversely, knocking out PCSK9 had minimal impact on brain cholesterol and hydroxysterol levels.

CONCLUSIONS

In vitro studies showed a pro-inflammatory effect of PCSK9. Consistently, in vivo data indicated a protective role of PCSK9 ablation against cognitive impairments, associated with improved Aβ pathology and attenuated neuroinflammation in a severe mouse model of AD. PCSK9 may thus be considered a novel pharmacological target for the treatment of AD.

Twenty-year trajectories of cardio-metabolic factors among people with type 2 diabetes by dementia status in England: a retrospective cohort study

To assess 20-year retrospective trajectories of cardio-metabolic factors preceding dementia diagnosis among people with type 2 diabetes (T2D). We identified 227,145 people with T2D aged > 42 years between 1999 and 2018. Annual mean levels of eight routinely measured cardio-metabolic factors were extracted from the Clinical Practice Research Datalink. Multivariable multilevel piecewise and non-piecewise growth curve models assessed retrospective trajectories of cardio-metabolic factors by dementia status from up to 19 years preceding dementia diagnosis (dementia) or last contact with healthcare (no dementia). 23,546 patients developed dementia; mean (SD) follow-up was 10.0 (5.8) years. In the dementia group, mean systolic blood pressure increased 16-19 years before dementia diagnosis compared with patients without dementia, but declined more steeply from 16 years before diagnosis, while diastolic blood pressure generally declined at similar rates. Mean body mass index followed a steeper non-linear decline from 11 years before diagnosis in the dementia group. Mean blood lipid levels (total cholesterol, LDL, HDL) and glycaemic measures (fasting plasma glucose and HbA1c) were generally higher in the dementia group compared with those without dementia and followed similar patterns of change. However, absolute group differences were small. Differences in levels of cardio-metabolic factors were observed up to two decades prior to dementia diagnosis. Our findings suggest that a long follow-up is crucial to minimise reverse causation arising from changes in cardio-metabolic factors during preclinical dementia. Future investigations which address associations between cardiometabolic factors and dementia should account for potential non-linear relationships and consider the timeframe when measurements are taken.

Exploring what progress is being made in the development of health promotion material for vascular dementia: A systematic review of the evidence

A systematic review conducted by Price and Keady (Journal of Nursing and Healthcare of Chronic Illness, 2, 88 and 2010) demonstrated that there was a dearth of health-promoting literature available for people diagnosed with vascular dementia. The correlation between health behavior and the onset of cardiovascular change that can lead to vascular dementia had demonstrated a need for health education and health-promoting information to be made accessible to vulnerable populations to ameliorate the risk of cognitive decline because of cardiovascular disease. Dementia is a progressive and life-limiting condition and with limited treatment options and a lack of progress in identifying a way to delay onset or even cure the condition. Focus must be targeted towards risk reduction strategies that serve to reduce onset and decline and limit the global burden on not only the individual with the condition and their carers but also to the health and social care economy. To identify the progress that has been made in developing health-promoting literature and patient education guidance since 2010 a systematic literature review was undertaken. Using thematic analysis, CINAHL, MEDLINE, and psych INFO databases were accessed and following PRISMA guidelines an inclusion and exclusion criteria was developed in order to locate peer-reviewed articles. Titles and abstracts were reviewed to identify a match with key terms, and from 133 screened abstracts eight studies met the inclusion requirements. From the eight studies, thematic analysis was implemented to identify shared understanding of experiences relating to health promotion in vascular dementia. The methodology for the study was replicated from the authors' previous systematic review in 2010. Five key themes were identified in the literature (Healthy heart healthy brain; Risk factors; Risk reduction/modification; Interventions; Absence of targeted health promotion). From what little evidence was available to review the thematic analysis has demonstrated developments in knowledge into the link between the onset of cognitive impairment and vascular dementia because of compromised cardiovascular health. Modifying health behavior has become essential in ameliorating the risk of vascular cognitive decline. With these developments the synthesis of the literature demonstrates that even with these insights there continues to be a lack of targeted material that individuals can access to understand the link between cardiovascular health and cognitive decline. It is recognized that maximizing cardiovascular health has the potential to lessen the risk of vascular cognitive impairment and vascular dementia developing and progressing yet targeted health promoting material remains lacking. With the developments in understanding the causal links between poor cardiovascular health, vascular cognitive impairment, and vascular dementia progress now needs to be made in developing targeted health promotion material for individuals to access to share this knowledge to reduce the potential onset and subsequent burden of dementia.

High cholesterol levels change the association of biomarkers of neurodegenerative diseases with dementia risk: Findings from a population-based cohort

INTRODUCTION

This study assessed whether in a population with comorbidity of neurodegenerative and cerebrovascular disease (mixed pathology) the association of glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), and phosphorylated tau181 (p-tau181) with dementia risk varied depending on levels of total cholesterol and apolipoprotein E (APOE) ε4 genotype.

METHODS

Plasma biomarkers were measured using Simoa technology in 768 participants of a nested case-control study embedded within an ongoing population-based cohort. Logistic and spline regression models, and receiver operating characteristic curves were calculated.

RESULTS

The strength of the association between GFAP and NfL with risk of a clinical diagnosis of dementia changed depending on cholesterol levels and on APOE ε4 genotype. No significant association was seen with p-tau181.

DISCUSSION

In individuals with mixed pathology blood GFAP and NfL are better predictors of dementia risk than p-tau181, and their associations with dementia risk are amplified by hypercholesterolemia, also depending on APOE ε4 genotype.

HIGHLIGHTS

Cholesterol levels changed the association of blood biomarkers with dementia risk. Blood biomarkers seem to perform differently in community- and clinic-based cohorts. Neurofilament light chain might be a biomarker candidate for dementia risk after stroke.

Role of Oxysterols in the Activation of the NLRP3 Inflammasome as a Potential Pharmacological Approach in Alzheimer's Disease

Alzheimer's disease (AD), the most prevalent form of dementia, is a complex clinical condition with multifactorial origin posing a major burden to health care systems across the world. Even though the pathophysiological mechanisms underlying the disease are still unclear, both central and peripheral inflammation has been implicated in the process. Piling evidence shows that the nucleotide-binding domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome is activated in AD. As dyslipidemia is a risk factor for dementia, and cholesterol can also activate the inflammasome, a possible link between lipid levels and the NLRP3 inflammasome has been proposed in Alzheimer's. It is also speculated that not only cholesterol but also its metabolites, the oxysterols, may be involved in AD pathology. In this context, mounting data suggest that NLRP3 inflammasome activity can be modulated by different peripheral nuclear receptors, including liver-X receptors, which present oxysterols as endogenous ligands. In light of this, the current review explores whether the activation of NLRP3 by nuclear receptors, mediated by oxysterols, may also be involved in AD and could serve as a potential pharmacological avenue in dementia.

Exploring the Role of Lipid-Binding Proteins and Oxidative Stress in Neurodegenerative Disorders: A Focus on the Neuroprotective Effects of Nutraceutical Supplementation and Physical Exercise

The human brain is primarily composed of lipids, and their homeostasis is crucial to carry on normal neuronal functions. In order to provide an adequate amount of lipid transport in and out of the central nervous system, organisms need a set of proteins able to bind them. Therefore, alterations in the structure or function of lipid-binding proteins negatively affect brain homeostasis, as well as increase inflammation and oxidative stress with the consequent risk of neurodegeneration. In this regard, lifestyle changes seem to be protective against neurodegenerative processes. Nutraceutical supplementation with antioxidant molecules has proven to be useful in proving cognitive functions. Additionally, regular physical activity seems to protect neuronal vitality and increases antioxidant defenses. The aim of the present review was to investigate mechanisms that link lipid-binding protein dysfunction and oxidative stress to cognitive decline, also underlining the neuroprotective effects of diet and exercise.

Higher Total Cholesterol Concentration May Be Associated with Better Cognitive Performance among Elderly Females

BACKGROUND

The brain contains the highest level of cholesterol in the body, and the total amount of serum cholesterol in the blood has a huge impact on brain aging and cognitive performance. However, the association of total serum cholesterol with cognitive function remains uncertain. This study determines whether there is an association between the total amount of cholesterol in the blood and cognitive performance in elderly females without a history of stroke.

METHODS

This population-based cross-sectional study was conducted on elderly (over 60 years old) females and males without a history of stroke from 2011 to 2014 in the US National Health and Nutrition Examination Survey (NHANES). The primary exposure was total blood cholesterol, and the main outcome was cognitive performance; this association was assessed with logistic regression analysis and restricted cubic splines.

RESULTS

1309 female and 1272 male participants were included. In females, higher total cholesterol was significantly associated with higher cognitive scores, particularly in the digit symbol substitution test (OR 0.51, 95% CI (0.36-0.72)) and the animal fluency test (OR 0.64, 95% CI (0.45-0.91)). This association remained significant in models adjusted for age, race, smoking status, education level, and chronic conditions (OR 0.40, 95% CI (0.25-0.63)). This association was not significant in males, however.

CONCLUSIONS

A higher concentration of total cholesterol measured in later life may be a protective factor for cognitive performance among females over 60 years old without a history of stroke. Further, this association was more pronounced among women with higher levels of education than women with lower or no education.

Cholesterol as a key player in amyloid β-mediated toxicity in Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative disorder that is one of the most devastating and widespread diseases worldwide, mainly affecting the aging population. One of the key factors contributing to AD-related neurotoxicity is the production and aggregation of amyloid β (Aβ). Many studies have shown the ability of Aβ to bind to the cell membrane and disrupt its structure, leading to cell death. Because amyloid damage affects different parts of the brain differently, it seems likely that not only Aβ but also the nature of the membrane interface with which the amyloid interacts, helps determine the final neurotoxic effect. Because cholesterol is the dominant component of the plasma membrane, it plays an important role in Aβ-induced toxicity. Elevated cholesterol levels and their regulation by statins have been shown to be important factors influencing the progression of neurodegeneration. However, data from many studies have shown that cholesterol has both neuroprotective and aggravating effects in relation to the development of AD. In this review, we attempt to summarize recent findings on the role of cholesterol in Aβ toxicity mediated by membrane binding in the pathogenesis of AD and to consider it in the broader context of the lipid composition of cell membranes.

Association of Familial Hypercholesterolemia and Statin Use With Risk of Dementia in Norway

IMPORTANCE

Hypercholesterolemia, which is a cardiovascular risk factor, may also be associated with dementia risk. The benefit of statin treatment on dementia risk is controversial.

OBJECTIVE

To determine whether individuals with familial hypercholesterolemia (FH), who have been exposed to lifelong hypercholesterolemia, have an excess risk of dementia and whether statin use is associated with dementia risk.

DESIGN, SETTING, AND PARTICIPANTS

This was a prospective cohort study performed from 2008 to 2018 in Norway. Statistical analysis was performed from January 2021 to February 2022. This study included individuals with genetically verified FH and age-matched and sex-matched controls obtained from the general Norwegian population.

EXPOSURES

Dementia was defined according to International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes F00-03 and G30.

MAIN OUTCOMES AND MEASURES

Incident cases of total dementia, vascular dementia, Alzheimer disease-dementia in Alzheimer disease, and data on lipid-lowering medication were obtained from the Norwegian Patient Registry, Cause of Death Registry, and the Norwegian Prescription Database. Hazard ratios (HRs) for risk of dementia for individuals with FH vs matched controls were calculated using Cox regression. The cumulative sum of defined daily doses (DDDs) of statins prescribed during study follow-up was calculated for individuals with FH and was analyzed as a time-varying covariate with 3 levels: 1 to 4999 DDDs, 5000 to 10 000 DDDs, and more than 10 000 DDDs.

RESULTS

Among the 3520 individuals with FH (1863 women [52.9%]; mean [SD] age at the start of follow-up, 51.8 [11.5] years) and the 69 713 controls (36 958 women [53.0%]; mean [SD] age at the start of follow-up, 51.7 [11.5] years), 62 patients with FH (39 women [62.9%]) and 1294 controls (801 women [61.9%]) had developed dementia over the course of 10 years of follow-up. Most dementia cases occurred among individuals aged 70 years and older (39 patients with FH [62.9%] and 870 patients [67.2%] in the control group). We found no excess risk of dementia in patients with FH vs matched controls (HR for total dementia, 0.9; 95% CI, 0.7-1.2). There was no association between cumulative DDDs of statins and total dementia in patients with FH with HRs of 1.2 (95% CI, 0.4-3.8) for cumulative DDDs of 5000 to 10 000 and 1.9 (95% CI, 0.7-5.0) for cumulative DDDs greater than 10 000.

CONCLUSIONS AND RELEVANCE

These findings suggest that individuals with FH have no excess risk of dementia compared with age-matched and sex-matched controls and that there is no association between use of statins and risk of dementia in patients with FH.

Pathophysiological features in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats

Diabetes mellitus (DM) and obesity are associated with neurodegenerative diseases such as Alzheimer's disease and psychiatric disorders such as major depression. In this study, we investigated pathophysiological changes in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats with diabetes and obesity. Brains of Sprague-Dawley (SD), SDT and SDT fatty rats were collected at 58 weeks of age. The parietal cortical thickness was measured and the number of pyramidal cells in the hippocampal cornu ammonis 1 and 3 (CA1 and CA3) and the number of granule cells in the dentate gyrus (DG) regions were counted. The area of glial fibrillary acidic protein (GFAP) positivity in CA1, CA3 and DG regions were measured. The parietal cortical thickness and the number of cells in CA3 and DG regions of SDT and SDT fatty rats did not show obvious changes. On the other hand, in the CA1 region, the number of cells in SDT rats and SDT fatty rats was significantly lower than that in SD rats, and that in SDT fatty rats was significantly lower than that in SDT rats. The GFAP-positive area in SDT fatty rats was significantly reduced compared to that in SD rats only in the DG region. Preliminarily result showed that the expression of S100a9, an inflammation-related gene, was increased in the brains of SDT fatty rats. These results suggest that female SDT fatty rat may exhibit central nervous system diseases due to obesity and DM.

Blood metabolites predicting mild cognitive impairment in the study of Latinos-investigation of neurocognitive aging (HCHS/SOL)

Introduction

Blood metabolomics‐based biomarkers may be useful to predict measures of neurocognitive aging.

Methods

We tested the association between 707 blood metabolites measured in 1451 participants from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), with mild cognitive impairment (MCI) and global cognitive change assessed 7 years later. We further used Lasso penalized regression to construct a metabolomics risk score (MRS) that predicts MCI, potentially identifying a different set of metabolites than those discovered in individual‐metabolite analysis.

Results

We identified 20 metabolites predicting prevalent MCI and/or global cognitive change. Six of them were novel and 14 were previously reported as associated with neurocognitive aging outcomes. The MCI MRS comprised 61 metabolites and improved prediction accuracy from 84% (minimally adjusted model) to 89% in the entire dataset and from 75% to 87% among apolipoprotein E ε4 carriers.

Discussion

Blood metabolites may serve as biomarkers identifying individuals at risk for MCI among US Hispanics/Latinos.

Association Between Egg Consumption and Dementia Risk in the EPIC-Spain Dementia Cohort

Background

Current evidence suggests that egg composition might have potential neuroprotective effects. Our aim was to determine the association between egg consumption and the risk of dementia in a Mediterranean population.

Methods

This study was carried out in 3 centers from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain Dementia Cohort, i.e., 25,015 participants aged 30–70 years, recruited in 1992–1996, and followed up for a mean of 21.5 years.

Results

A total of 774 incident dementia cases were diagnosed and validated, of which 518 were Alzheimer's disease (AD). Data on egg consumption were estimated using a validated dietary history questionnaire at recruitment. Cox proportional hazards models, adjusted for confounders, were used in the analyses. No association was observed between egg consumption and either total dementia [hazard ratio between extreme quartiles (HR_Q4vs.Q1: 1.05; 95% CI 0.85–1.31; p-trend = 0.93)] or AD (HR_Q4vs.Q1 0.93; 95% CI 0.72–1.21; p-trend = 0.50) risks. After dividing the population by adherence to the relative Mediterranean diet (rMED) score, a borderline inverse association was found between egg intake and both total dementia (HR_Q4vs.Q1: 0.52; 95% CI 0.30–0.90; p-trend = 0.10) and AD (HR_Q4vs.Q1: 0.52; 95% CI 0.27–1.01; p-trend = 0.13) risks within participants with low adherence to rMED score. However, no association was observed in participants with medium and high adherence to rMED score.

Conclusion

This prospective study suggests that egg consumption is associated with a reduced risk of dementia, and specifically of AD, in the adult population with low adherence to rMED score; whereas it has no impact in subjects with moderate and high MD adherence.

Neurodegenerative Diseases and Cholesterol: Seeing the Field Through the Players

Neurodegenerative diseases, namely Alzheimer’s (AD), Parkinson’s (PD), and Huntington’s disease (HD) together with amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS), devastate millions of lives per year worldwide and impose an increasing socio-economic burden across nations. Consequently, these diseases occupy a considerable portion of biomedical research aiming to understand mechanisms of neurodegeneration and to develop efficient treatments. A potential culprit is cholesterol serving as an essential component of cellular membranes, as a cofactor of signaling pathways, and as a precursor for oxysterols and hormones. This article uncovers the workforce studying research on neurodegeneration and cholesterol using the TeamTree analysis. This new bibliometric approach reveals the history and dynamics of the teams and exposes key players based on citation-independent metrics. The team-centered view reveals the players on an important field of biomedical research.

Burning Fog: Cognitive Impairment in Burning Mouth Syndrome

Background: Due to its common association with chronic pain experience, cognitive impairment (CI) has never been evaluated in patients with burning mouth syndrome (BMS). The purpose of this study is to assess the prevalence of CI in patients with BMS and to evaluate its relationship with potential predictors such as pain, mood disorders, blood biomarkers, and white matter changes (WMCs).

Methods: A case-control study was conducted by enrolling 40 patients with BMS and an equal number of healthy controls matched for age, gender, and education. Neurocognitive assessment [Mini Mental State Examination (MMSE), Digit Cancellation Test (DCT), the Forward and Backward Digit Span task (FDS and BDS), Corsi Block-Tapping Test (CB-TT), Rey Auditory Verbal Learning Test (RAVLT), Copying Geometric Drawings (CGD), Frontal Assessment Battery (FAB), and Trail Making A and B (TMT-A and TMT-B)], psychological assessment [Hamilton Rating Scale for Depression and Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and 36-Item Short Form Health Survey (SF-36)], and pain assessment [Visual Analogic Scale (VAS), Total Pain Rating index (T-PRI), Brief Pain Inventory (BPI), and Pain DETECT Questionnaire (PD-Q)] were performed. In addition, blood biomarkers and MRI of the brain were recorded for the detection of Age-Related WMCs (ARWMCs). Descriptive statistics, the Mann-Whitney U-test, the Pearson Chi-Squared test and Spearman's correlation analysis were used.

Results: Patients with BMS had impairments in most cognitive domains compared with controls (p < 0.001^**) except in RAVLT and CGD. The HAM-D, HAM-A, PSQI, ESS, SF-36, VAS, T-PRI, BPI and PD-Q scores were statistically different between BMS patients and controls (p < 0.001^**) the WMCs frequency and ARWMC scores in the right temporal (RT) and left temporal (LT) lobe were higher in patients with BMS (p = 0.023^*).

Conclusions: Meanwhile, BMS is associated with a higher decline in cognitive functions, particularly attention, working memory, and executive functions, but other functions such as praxis-constructive skills and verbal memory are preserved. The early identification of CI and associated factors may help clinicians to identify patients at risk of developing time-based neurodegenerative disorders, such as Alzheimer's disease (AD) and vascular dementia (VD), for planning the early, comprehensive, and multidisciplinary assessment and treatment.

Promoting Successful Cognitive Aging: A Ten-Year Update

A decade has passed since we published a comprehensive review in this journal addressing the topic of promoting successful cognitive aging, making this a good time to take stock of the field. Because there have been limited large-scale, randomized controlled trials, especially following individuals from middle age to late life, some experts have questioned whether recommendations can be legitimately offered about reducing the risk of cognitive decline and dementia. Despite uncertainties, clinicians often need to at least make provisional recommendations to patients based on the highest quality data available. Converging lines of evidence from epidemiological/cohort studies, animal/basic science studies, human proof-of-concept studies, and human intervention studies can provide guidance, highlighting strategies for enhancing cognitive reserve and preventing loss of cognitive capacity. Many of the suggestions made in 2010 have been supported by additional research. Importantly, there is a growing consensus among major health organizations about recommendations to mitigate cognitive decline and promote healthy cognitive aging. Regular physical activity and treatment of cardiovascular risk factors have been supported by all of these organizations. Most organizations have also embraced cognitively stimulating activities, a heart-healthy diet, smoking cessation, and countering metabolic syndrome. Other behaviors like regular social engagement, limiting alcohol use, stress management, getting adequate sleep, avoiding anticholinergic medications, addressing sensory deficits, and protecting the brain against physical and toxic damage also have been endorsed, although less consistently. In this update, we review the evidence for each of these recommendations and offer practical advice about behavior-change techniques to help patients adopt brain-healthy behaviors.

Statin therapy and risk of Alzheimer's and age-related neurodegenerative diseases

INTRODUCTION

Establishing efficacy of and molecular pathways for statins has the potential to impact incidence of Alzheimer's and age-related neurodegenerative diseases (NDD).

METHODS

This retrospective cohort study surveyed US-based Humana claims, which includes prescription and patient records from private-payer and Medicare insurance. Claims from 288,515 patients, aged 45 years and older, without prior history of NDD or neurological surgery, were surveyed for a diagnosis of NDD starting 1 year following statin exposure. Patients were required to be enrolled with claims data for at least 6 months prior to first statin prescription and at least 3 years thereafter. Computational system biology analysis was conducted to determine unique target engagement for each statin.

RESULTS

Of the 288,515 participants included in the study, 144,214 patients (mean [standard deviation (SD)] age, 67.22 [3.8] years) exposed to statin therapies, and 144,301 patients (65.97 [3.2] years) were not treated with statins. The mean (SD) follow-up time was 5.1 (2.3) years. Exposure to statins was associated with a lower incidence of Alzheimer's disease (1.10% vs 2.37%; relative risk [RR], 0.4643; 95% confidence interval [CI], 0.44-0.49; P < .001), dementia 3.03% vs 5.39%; RR, 0.56; 95% CI, 0.54-0.58; P < .001), multiple sclerosis (0.08% vs 0.15%; RR, 0.52; 95% CI, 0.41-0.66; P < .001), Parkinson's disease (0.48% vs 0.92%; RR, 0.53; 95% CI, 0.48-0.58; P < .001), and amyotrophic lateral sclerosis (0.02% vs 0.05%; RR, 0.46; 95% CI, 0.30-0.69; P < .001). All NDD incidence for all statins, except for fluvastatin (RR, 0.91; 95% CI, 0.65-1.30; P = 0.71), was reduced with variances in individual risk profiles. Pathway analysis indicated unique and common profiles associated with risk reduction efficacy.

DISCUSSION

Benefits and risks of statins relative to neurological outcomes should be considered when prescribed for at-risk NDD populations. Common statin activated pathways indicate overarching systems required for risk reduction whereas unique targets could advance a precision medicine approach to prevent neurodegenerative diseases.