Incidence of dementia and cognitive impairment, not dementia in the United States

Age-dependent sex differences in cofilin1 pathway (LIMK1/SSH1) and its association with AD biomarkers after chronic systemic inflammation in mice

Chronic systemic inflammation (CSI) results in neuroinflammation and neurodegeneration. Cofilin1 is a stress protein that activates microglia and induces neuroinflammation, but its role in CSI at different aging stages remains unidentified. Therefore, the study aims to identify cofilin1 and its upstream regulators LIMK1 and SSH1 after CSI in young-, middle-, and advanced-aged mice. CSI was induced by injecting the male and female mice with a sub-lethal dose of Lipopolysaccharide weekly for six weeks. The results showed that normal male mice did not show cofilin pathway dysregulation, but a significant dysregulation was observed in CSI advanced-aged mice. In females, cofilin1 dysregulation was observed in healthy and CSI advanced-aged mice, while significant cofilin1 dysregulation was observed in middle-aged mice during CSI. Furthermore, cofilin1 pathway dysregulations correlated with Alzheimer's disease (AD) biomarkers in the brain and saliva, astrocyte activation, synaptic degeneration, neurobehavioral impairments, gut-microbiota abnormalities, and circulatory inflammation. These results provide new insights into cofilin1 sex and age-dependent mechanistic differences that might help identify targets for modulating neuroinflammation and early onset of AD.

Alzheimer disease blood biomarkers: considerations for population-level use

In the past 5 years, we have witnessed the first approved Alzheimer disease (AD) disease-modifying therapy and the development of blood-based biomarkers (BBMs) to aid the diagnosis of AD. For many reasons, including accessibility, invasiveness and cost, BBMs are more acceptable and feasible for patients than a lumbar puncture (for cerebrospinal fluid collection) or neuroimaging. However, many questions remain regarding how best to utilize BBMs at the population level. In this Review, we outline the factors that warrant consideration for the widespread implementation and interpretation of AD BBMs. To set the scene, we review the current use of biomarkers, including BBMs, in AD. We go on to describe the characteristics of typical patients with cognitive impairment in primary care, who often differ from the patient populations used in AD BBM research studies. We also consider factors that might affect the interpretation of BBM tests, such as comorbidities, sex and race or ethnicity. We conclude by discussing broader issues such as ethics, patient and provider preference, incidental findings and dealing with indeterminate results and imperfect accuracy in implementing BBMs at the population level.

Age-specific risk factors of depression among the oldest-old - evidence from the multicenter AgeCoDe-AgeQualiDe study

Purpose

The present study aimed to investigate age-group-specific incidence rates and risk factors for depressive symptoms in the highest age groups.

Methods

Data were derived from a prospective multicenter cohort study conducted in primary care - the AgeCoDe/AgeQualiDe study. In total, 2,436 patients 75 years and older were followed from baseline to ninth follow-up. To assess depressive symptoms, the short version of the Geriatric Depression Scale (GDS-15, cutoff score 6) was used. Age-specific competing risk regressions were performed to analyze risk factors for incident depressive symptoms in different age groups (75 to 79, 80 to 84, 85+ years), taking into account the accumulated mortality.

Results

The age-specific incidence rate of depression was 33 (95% CI 29-38), 46 (95% CI 40-52) and 63 (95% CI 45-87) per 1,000 person years for the initial age groups 75 to 79, 80 to 84 and 85+ years, respectively. In competing risk regression models, female sex, mobility as well as vision impairment, and subjective cognitive decline (SCD) were found to be risk factors for incident depression for age group 75 to 79, female sex, single/separated marital status, mobility as well as hearing impairment, and SCD for age group 80 to 84, and mobility impairment for age group 85+.

Conclusion

Depressive symptoms in latest life are common and the incidence increases with increasing age. Modifiable and differing risk factors across the highest age groups open up the possibility of specifically tailored prevention concepts.

Racial and ethnic disparities in genomic testing among lung cancer patients: a systematic review

BACKGROUND

Racial and ethnic disparities in genomic testing could exacerbate disparities in access to precision cancer therapies and survival-particularly in the context of lung cancer where genomic testing has been recommended for the past decade. However, prior studies assessing disparities in genomic testing have yielded mixed results.

METHODS

We conducted a systemic review to examine racial and ethnic disparities in the use of genomic testing among lung cancer patients in the United States. Two comprehensive searches in PubMed, Embase, and Scopus were conducted (September 2022, May 2023). Original studies that assessed rates of genomic testing by race or ethnicity were included. Findings were narratively synthesized by outcome.

RESULTS

The search yielded 2739 unique records, resulting in 18 included studies. All but 1 study were limited to patients diagnosed with non-small cell lung cancer. Diagnosis years ranged from 2007 to 2022. Of the 18 studies, 11 found statistically significant differences in the likelihood of genomic testing by race or ethnicity; in 7 of these studies, testing was lower among Black patients compared with White or Asian patients. However, many studies lacked adjustment for key covariates and included patients with unclear eligibility for testing.

CONCLUSIONS

A majority of studies, though not all, observed racial and ethnic disparities in the use of genomic testing among patients with lung cancer. Heterogeneity of study results throughout a period of changing clinical guidelines suggests that minoritized populations-Black patients in particular-have faced additional barriers to genomic testing, even if not universally observed at all institutions.

Perceived Discrimination and Incident Dementia Among Older Adults in the United States: The Buffering Role of Social Relationships

OBJECTIVES

Recent studies have found that perceived discrimination as a chronic stressor predicts poorer cognitive health. However, little research has investigated how social relationships as potential intervening mechanisms may mitigate or exacerbate this association. Using a nationally representative sample of U.S. older adults, this study examined how the existence and quality of 4 types of relationships-with a partner, children, other family members, and friends-may modify the impact of perceived discrimination on incident dementia.

METHODS

We analyzed data from the 2006 to 2016 Health and Retirement Study (N = 12,236) using discrete-time event history models with competing risks. We used perceived discrimination, social relationships, and their interactions at the baseline to predict the risk of incident dementia in the follow-ups.

RESULTS

Perceived discrimination predicted a higher risk of incident dementia in the follow-ups. Although having a partner or not did not modify this association, partnership support attenuated the negative effects of discrimination on incident dementia. Neither the existence nor quality of relationships with children, other family members, or friends modified the association.

DISCUSSION

Our findings imply that intimate partnership plays a critical role in coping with discrimination and, consequently, influencing the cognitive health of older adults. Although perceived discrimination is a significant risk factor for the incidence of dementia, better partnership quality may attenuate this association. Policies that eliminate discrimination and interventions that strengthen intimate partnerships may facilitate better cognitive health in late life.

Factors associated with reduced sleep among spouses and caregivers of older adults with varying levels of cognitive decline

BACKGROUND

Caregivers of persons with cognitive decline (PWCD) are at increased risk of poor sleep quantity and quality. It is unclear whether this is due to factors in the caregiver versus in the PWCD.

METHODS

This secondary data analysis using Aging, Demographics, and Memory Study data from the Health Retirement Study examined factors contributing to reduced sleep/rest among spouses and caregivers of older adults with varying levels of cognitive decline (cognitively normal (CN), cognitive impairment but not dementia (CIND), or dementia).

RESULTS

In our preliminary analysis, among N = 218 spouses (not necessarily caregivers) (mean age (SD) = 73.77 (7.30); 70.64% female) of older adults with varying levels of cognitive decline, regression revealed that frequency of sleep complaints was lowest among spouses with CN partners, second highest with CIND partners, and highest with dementia-partners, X2  = 26.810, P = 0.002.

PRIMARY AIM

among n = 136 caregivers of PWCD (mean age (SD) = 59.27 (13.97); 74.26% female; 22.79% spouses), we analyzed whether caregiver reduced sleep/rest was predicted by PWCD factors (i.e., frequent nighttime waking, dementia severity) and/or caregiver factors (i.e., depression symptoms, caregiver role overload). Regression revealed that caregiver depression symptoms (d = 0.62) and role overload (d = 0.88), but not PWCD factors, were associated with reduced caregiver sleep/rest after adjusting for demographic factors, caregiving frequency, and shared-dwelling status (overall model: X2  = 31.876, P = 0.002). Exploratory analyses revealed that a caregiver was 7.901 times more likely (95% CI: 0.99-63.15) to endorse experiencing reduced sleep/rest if back-up care was not available (P = 0.023).

CONCLUSION

Findings highlight that the frequency of reported sleep problems among spouses increases in a stepwise fashion when partners have dementia versus CIND versus CN. The results also emphasise that caregiver mental health and burden are strongly associated with caregiver sleep disturbances and thus may be targets of intervention for caregiver sleep problems.

Perspectives of general practitioners and memory clinic patients on ageing and cognitive decline to inform the design of a decentralised antihypertensive dementia prevention trial

BACKGROUND

The global burden dementia is growing each year. Clinical trials investigating approaches to preventing dementia have been occurring for decades, but they are particularly challenging including the requirement to include large numbers of healthy 'at-risk' people who need to be followed up for a long period of time. Community and consumer involvement in trial design helps to ensure that the methods are acceptable to the involved stakeholders, the design and operation of clinical trials are suitable and applicable to the target population, and that key areas of concern are identified and addressed at an early stage.

OBJECTIVES

To gain insights from samples of memory clinic patients without dementia and general practitioners on the acceptability of, and attitudes towards, the proposed design of a decentralised antihypertensive dementia prevention trial. Topics addressed included the assessment of cognition, antihypertensive medication use, and motivation to participate in research.

METHODS

Two focus groups (total n = 7) with memory clinic patients and individual interviews with GPs (n = 5) were conducted. Transcripts were analysed using qualitative thematic framework analysis.

RESULTS

The proposed design was acceptable, with some possible barriers identified regarding computer use, GP time restraints, and concerns about medication interactions. Additional themes included the importance of communication and social connectedness in research participation and perceptions of ageing in medical settings. Future directions of research into larger studies and consumer-led research practices were discussed.

CONCLUSION

The proposed trial design was agreed to be acceptable with some operational considerations, which were incorporated in the trial design.

The importance of education for understanding variability of dementia onset in the United States

BACKGROUND

Greater levels of education are associated with lower risk of dementia, but less is known about how education is also associated with the compression of dementia incidence.

OBJECTIVE

We extend the literature on morbidity compression by evaluating whether increased levels of education are associated with greater dementia compression. We evaluate these patterns across race and gender groups.

METHODS

We use the Health and Retirement Study (2000-2016), a nationally representative longitudinal study of older adults in the United States. To evaluate the onset and compression of dementia across education groups, we examine the age-specific distribution of dementia events, identifying the modal age of onset and the standard deviation above the mode (a measure of compression).

RESULTS

While the modal age of onset is around 85 years among adults with a college degree, the modal age for adults with less than a high school education occurs before age 65 - at least a 20-year difference. The standard deviation of dementia onset is about three times greater for adults with less than a high school education compared to adults with a college degree. Patterns were consistent across race and gender groups.

CONCLUSION

This research highlights the variability of dementia experiences in the older population by documenting differences in longevity without dementia and compression of dementia onset among more educated adults and less educated adults.

CONTRIBUTION

We incorporate conceptual insights from the life span variability and compression literature to better understand education-dementia disparities in both the postponement and uncertainty of dementia onset in the US population.

Progression and trajectory network of age-related functional impairments and their combined associations with mortality

Age-related functional impairments (ARFIs) contribute to the loss of independence in older adults, but their progressions, interrelations, and combined relations with mortality are largely unknown. We conducted a prospective study among 17,914 participants in the Health and Retirement Study (2000-2020). The incidence rates of visual impairment, hearing impairment, physical frailty, and cognitive impairment increased exponentially with age, while those of restless sleep and depression increased relatively slowly. These ARFIs were associated with each other in temporal sequence and constituted a hazard network. We observed a dose-response relationship between the number of ARFIs and mortality risk, and the dyads involving physical frailty demonstrated the strongest associations with mortality. Our findings may assist in the identification of individuals at higher mortality risk and highlight the potential for future investigations to explore the impact of multiple ARFIs in aging.

Perceived discrimination and nativity status: risk of cognitive impairment among Latin American older adults

OBJECTIVES

We examined the association between perceived discrimination and the risk of cognitive impairment with no dementia (CIND) and Alzheimer's disease and related dementias (ADRD) while considering the potential effects of nativity status.

DESIGN

A prospective analysis of discrimination and nativity status with dementia and cognitive impairment was conducted among Latinx adults aged 51 years and older who participated in the Health and Retirement Study.

SETTING

A national representative sample.

PARTICIPANTS

A sample of 1,175 Latinx adults aged 51 years and older.

MEASUREMENTS

Demographics, cognitive functioning, perceived discrimination, and nativity status (US-born vs. non-US born) were assessed. Traditional survival analysis methods (Fine and gray models) were used to account for the semi-competing risk of death with up to 10 years of follow-up.

RESULTS

According to our results, neither everyday discrimination nor nativity status on their own had a statistically significant association with CIND/ADRD; however, non-US-born Latinx adults who reported no discrimination had a 42% lower risk of CIND/ADRD (SHR = 0.58 [0.41, 0.83], p = .003) than US-born adults.

CONCLUSIONS

These results highlight the need for healthcare providers to assess for discrimination and provide support and resources for those experiencing discrimination. It also highlights the need for better policies that address discrimination and reduce health disparities.

Multimorbidity patterns and 18-year transitions from normal cognition to dementia and death: A population-based study

BACKGROUND

Several chronic diseases accelerate cognitive decline; however, it is still unknown how different patterns of multimorbidity influence individuals' trajectories across the cognitive continuum.

OBJECTIVES

We aimed to investigate the impact of multimorbidity and of specific multimorbidity patterns on the transitions across cognitive stages (normal cognition, cognitive impairment, no dementia [CIND], dementia) and death.

METHODS

We included 3122 dementia-free individuals from the Swedish National study on Aging and Care in Kungsholmen. Using fuzzy c-means cluster analysis, multimorbid participants were classified into mutually exclusive groups characterized by commonly coexisting chronic diseases. Participants were followed up to 18 years to detect incident CIND, dementia, or death. Transition hazard ratios (HRs), life expectancies, and time spent in different cognitive stages were estimated using multistate Markov models.

RESULTS

At baseline, five multimorbidity patterns were identified: neuropsychiatric, cardiovascular, sensory impairment/cancer, respiratory/metabolic/musculoskeletal, and unspecific. Compared to the unspecific pattern, the neuropsychiatric and sensory impairment/cancer ones showed reduced hazards of reverting from CIND to normal cognition (HR 0.53, 95% CI 0.33-0.85 and HR 0.60, 95% CI 0.39-0.91). Participants in the cardiovascular pattern exhibited an increased hazard of progression from CIND to dementia (HR 1.70, 95% CI 1.15-2.52) and for all transitions to death. Subjects with the neuropsychiatric and cardiovascular patterns showed reduced life expectancy at age 75, with an anticipation of CIND (up to 1.6 and 2.2 years, respectively) and dementia onset (up to 1.8 and 3.3 years, respectively).

CONCLUSIONS

Multimorbidity patterns differentially steer individual trajectories across the cognitive continuum of older adults and may be used as a risk stratification tool.

Beyond the amyloid hypothesis: how current research implicates autoimmunity in Alzheimer's disease pathogenesis

The amyloid hypothesis has so far been at the forefront of explaining the pathogenesis of Alzheimer's Disease (AD), a progressive neurodegenerative disorder that leads to cognitive decline and eventual death. Recent evidence, however, points to additional factors that contribute to the pathogenesis of this disease. These include the neurovascular hypothesis, the mitochondrial cascade hypothesis, the inflammatory hypothesis, the prion hypothesis, the mutational accumulation hypothesis, and the autoimmunity hypothesis. The purpose of this review was to briefly discuss the factors that are associated with autoimmunity in humans, including sex, the gut and lung microbiomes, age, genetics, and environmental factors. Subsequently, it was to examine the rise of autoimmune phenomena in AD, which can be instigated by a blood-brain barrier breakdown, pathogen infections, and dysfunction of the glymphatic system. Lastly, it was to discuss the various ways by which immune system dysregulation leads to AD, immunomodulating therapies, and future directions in the field of autoimmunity and neurodegeneration. A comprehensive account of the recent research done in the field was extracted from PubMed on 31 January 2022, with the keywords "Alzheimer's disease" and "autoantibodies" for the first search input, and "Alzheimer's disease" with "IgG" for the second. From the first search, 19 papers were selected, because they contained recent research on the autoantibodies found in the biofluids of patients with AD. From the second search, four papers were selected. The analysis of the literature has led to support the autoimmune hypothesis in AD. Autoantibodies were found in biofluids (serum/plasma, cerebrospinal fluid) of patients with AD with multiple methods, including ELISA, Mass Spectrometry, and microarray analysis. Through continuous research, the understanding of the synergistic effects of the various components that lead to AD will pave the way for better therapeutic methods and a deeper understanding of the disease.

Participatory and Receptive Arts Engagement in Older Adults: Associations with Cognition Over a Seven-Year Period

There is growing evidence for the impact of arts engagement on later life cognition. However, confounding by socioeconomic factors may have led to an overestimation of this association. We analyzed data from 4,344 older adults in the Wisconsin Longitudinal Study. We measured participatory (e.g. painting, making music, crafts) and receptive (e.g. concert, play, museum) arts engagement separately. Participants completed six neurocognitive tests measuring two distinct domains of cognitive function (episodic/working memory and executive function/language) concurrently and seven years later. We used inverse probability of treatment weighting (IPTW) to remove confounding by a range of demographic and socioeconomic factors. Engaging in participatory or receptive arts for up to one hour per week (but not more frequently) was associated with better subsequent executive function/language. Similarly, engaging in receptive arts activities for up to three hours per week (but not more frequently) was associated with better subsequent episodic/working memory. These effects were of similar sizes to doing vigorous physical activity for up to one hour per week. However, our findings also highlight key methodological issues when exploring the relationship between arts engagement and cognition that should be considered in future studies, including measurement bias, life-course stage, length of follow-up, variation in outcomes, attrition, and missing data.

Weight Loss Is a Strong Predictor of Memory Disorder Independent of Genetic Influences

BACKGROUND

Past studies identified a link between weight loss and dementia, but lacked consistent conclusions. We sought to establish this link by examining the weight change profiles before and after dementia diagnosis.

METHODS

Using data from the Health and Retirement Study (1996-2020), we examined 13,123 participants. We conducted a nested case-control analysis to assess differences in biennial weight change profile while controlling for BMI, longevity polygenic risk scores, and APOE gene variants.

RESULTS

Participants with a memory disorder lost weight (-0.63%) biennially, whereas those without a diagnosis did not (+0.013%, p-value < 0.0001). Our case-control study shows a significant difference (p-value < 0.01) in pre-dementia % weight changes between the cases (-0.29%) and controls (0.19%), but not in post-dementia weight changes. The weight loss group have the highest risk (OR = 2.01; p-value < 0.0001) of developing a memory disorder compared to the stable weight and weight gain groups. The observations hold true after adjusting for BMI, longevity polygenic risk scores, and APOE variant in a multivariable model.

CONCLUSIONS

We observe that weight loss in dementia is a physiological process independent of genetic factors associated with BMI and longevity. Pre-dementia weight loss may be an important prognostic criterion to assess a person's risk of developing a memory disorder.

From neurodevelopmental to neurodegenerative disorders: Investigating symptoms of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in patients with dementia

Dementia is characterized by a progressive cognitive decline that could be caused by several disorders. Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are two prevalent neurodevelopmental disorders that might overlap with dementia symptoms. Hence, this study aimed to evaluate the ASD and ADHD symptoms in dementia patients referred to a memory clinic in Iran. We recruited 65 dementia patients and instructed them to fill out the autism quotient (AQ) and the Conners' Adult ADHD Rating Scales (CAARS) questionnaires. Considering the cutoff points of AQ and CAARS questionnaires, 18.5% of participants were at higher risk of ASD, and 35.4% were at higher risk of ADHD. The results indicated that ADHD and ASD symptoms might be common comorbidities in patients with dementia which can increase the disease burden. Specialized ADHD and ASD screening tools in the elderly population with dementia are needed to prevent misdiagnoses due to symptom overlaps.

Prevalence of Malnutrition in People with Dementia in Long-Term Care: A Systematic Review and Meta-Analysis

Dementia is a common syndrome in older people. Dementia alters eating behaviors, hunger and thirst cues, swallow function, ability to self-feed, and recognition and interest in food. There is significant variation in the reported prevalence of malnutrition among older people who live in long-term care. The aim was to conduct a systematic literature review and meta-analysis of the prevalence of malnutrition in those with dementia living in long-term care using a validated nutrition assessment tool. Scopus, Web of Science, CINAHL, and Medline were searched. A random effects model was used to determine the prevalence and risk of malnutrition. Data were retrieved from 24 studies. Most of the studies were from Europe or South Asia. The prevalence of malnutrition ranged from 6.8 to 75.6%, and the risk of malnutrition was 36.5-90.4%. The pooled prevalence of malnutrition in those with dementia in long-term care was 26.98% (95% CI 22.0-32.26, p < 0.0001, I² = 94.12%). The pooled prevalence of the risk of malnutrition in those with dementia was 57.43% (95% CI 49.39-65.28, p < 0.0001, I² = 97.38%). Malnutrition is widespread in those with dementia living in long-term care. Further research exploring malnutrition in other industrialized countries using validated assessment tools is required.

Atrial fibrillation as a contributor to the mortality in patients with dementia: A nationwide cohort study

Background

Knowledge of the risk of death in patients with dementia is essential for planning preventive strategies. This study aimed to evaluate the effect of atrial fibrillation (AF) on death risks and other factors associated with death in patients with dementia and AF.

Methods

We conducted a nationwide cohort study using Taiwan's National Health Insurance Research Database. We identified subjects with dementia diagnosed for the first time and AF diagnosed concomitantly between 2013 and 2014. Subjects under the age of 18 years were excluded. Age, sex, and CHA2DS2-VASc scores were 1: 4 matched for AF patients (N = 1,679) and non-AF controls (N = 6,176) using the propensity score technique. The conditional Cox regression model and competing risk analysis were applied. The risk of mortality was tracked till 2019.

Results

AF history was associated with higher risks of all-cause death (hazard ratio [HR]: 1.208; 95% confidence interval [CI]: 1.142–1.277) and cardiovascular death (subdistribution HR: 1.210; 95% CI: 1.077–1.359) in dementia patients than patients without a diagnosis of AF. For patients with both dementia and AF, they had a higher risk of death due to higher age, diabetes mellitus, congestive heart failure, chronic kidney disease, and prior stroke. Anti-arrhythmic drugs and novel oral anticoagulants significantly reduced the risk of death in patients with AF and dementia.

Conclusion

This study found that AF is a risk factor for mortality in patients with dementia and explored several risk factors for AF-related mortality. This study highlights the importance of controlling AF especially in patients with dementia.

Feasibility of an online consensus approach for the diagnosis of cognitive impairment and dementia in rural South Africa

INTRODUCTION

We describe the development and feasibility of using an online consensus approach for diagnosing cognitive impairment and dementia in rural South Africa.

METHODS

Cognitive assessments, clinical evaluations, and informant interviews from Cognition and Dementia in the Health and Aging in Africa Longitudinal Study (HAALSI Dementia) were reviewed by an expert panel using a web-based platform to assign a diagnosis of cognitively normal, mild cognitive impairment (MCI), or dementia.

RESULTS

Six hundred thirty-five participants were assigned a final diagnostic category, with 298 requiring adjudication conference calls. Overall agreement between each rater's independent diagnosis and final diagnosis (via the portal or consensus conference) was 78.3%. A moderate level of agreement between raters' individual ratings and the final diagnostic outcomes was observed (average κ coefficient = 0.50).

DISCUSSION

Findings show initial feasibility in using an online consensus approach for the diagnosis of cognitive impairment and dementia in remote, rural, and low-resource settings.

End-of-life health care use among socially isolated and cognitively impaired older adults

BACKGROUND

Social isolation is common in the last years of life, especially among individuals with cognitive impairment (CI), but it is unknown if social isolation is related to end-of-life health care use.

METHODS

We used nationally-representative 2006-2018 Health and Retirement Study (HRS) data linked to Medicare claims, including adults age ≥65 interviewed in the last 4 years of life (N = 2380). We used a validated social isolation scale and three social isolation subscales: (1) household contacts (marital status, household size, nearby children), (2) social network interaction (with children, family, and friends), and (3) community engagement. End-of-life health outcomes included 2+ emergency department (ED) visits in the last month of life, hospitalizations or ICU stays in the last 6 months of life, and any hospice use. CI was defined using the validated Langa-Weir methodology. We used logistic regression to test the association of each social isolation measure with each end-of-life outcome, adjusted for sociodemographic covariates, and tested for interaction terms with CI (p < 0.2).

RESULTS

The mean age of our sample of decedents was 81.2 (SD = 9.9), 53% were female, 8% Black, and 4% Hispanic. Overall, social isolation and the community engagement subscale were not associated with end-of-life health care use. Fewer household contacts were associated with lower hospice use (aOR = 0.74, p = 0.005). There were significant interaction terms between the social network interaction subscale and CI for ED use (p = 0.009) and hospitalizations (p = 0.04), and a trend for ICU stays (p = 0.15); individuals with both low social network interaction and CI had lower health care use across all three outcomes compared to other groups.

CONCLUSIONS

Individuals with fewer household contacts had lower hospice use, and cognitively impaired individuals with low social network interaction had fewer end-of-life ED visits, hospitalizations, and ICU stays. Clinicians should consider mobilizing external support services to ensure access to goal-concordant care for older adults with limited end-of-life social contact when needed.

Sex differences in the mediating role of chronic inflammation on the association between social isolation and cognitive functioning among older adults in the United States

BACKGROUND

Previous research has reported the association between social isolation and cognitive impairment. However, biological mechanisms underlying this association are understudied. It is also unclear whether there are sex differences in these biological mechanisms.

OBJECTIVES

To examine whether chronic inflammation biomarkers are potential mediators of the association between social isolation and cognitive functioning among older men and women.

METHODS

Data were the National Health and Nutrition Examination Survey 1999-2002. A total of 2535 older adults aged 60 and older were included. Chronic inflammation was measured by C-reactive protein (CRP), plasma fibrinogen, and serum albumin. Cognitive functioning was assessed by the Digit Symbol Substitution Test (DSST). Social isolation was defined using a 4-point composite index of items pertaining to the strength of social network and support. Linear regression models and formal mediation analysis were applied.

RESULTS

Social isolation was associated with lower DSST scores [β (SE) = -2.445 (1.180), p < 0.01 for men; β (SE) = -5.478 (1.167), p < 0.001 for women]. For older men, social isolation was associated with higher levels of CRP (β [SE] = 0.226 (0.110), p < 0.05) and fibrinogen (β [SE] = 0.058 (0.026), p < 0.05). In mediation analyses, among older men, CRP mediated 6.1% and fibrinogen mediated 12.0% of the association of social isolation with DSST.

CONCLUSION

Social isolation was associated with poorer cognitive functioning partially via heightened inflammatory responses in older men. Defining these associations' mechanisms in sex-specific contexts could inform preventive and therapeutic strategies for cognitive impairment in older adults.

Association of Religious Service Attendance and Neuropsychiatric Symptoms, Cognitive Function, and Sleep Disturbances in All-Cause Dementia

Commonly reported in dementia, neuropsychiatric symptoms (NPS), cognitive decline, and sleep disturbances indicate dementia progression. With the growing dementia burden, identifying protective factors that may slow dementia progression is increasingly essential. Religion and spirituality are associated with better mental and physical health, yet few studies have been reported in older adults with dementia. This study examines associations between religious service attendance and symptoms of dementia progression. Using data from the Health and Retirement Study in 2000, 2006, and 2008 and the sub-study, Aging, Demographics, and Memory Study in 2001-2003, 2006-2007, and 2008-2009, we examined the association of religious attendance with neuropsychiatric symptoms, cognitive function, and sleep disturbances among U.S. older adults aged 70 years and older with all-cause dementia (N = 72) using Spearman's partial Rho correlation controlling for social interaction. Significant associations were identified for religious attendance and NPS (r_s (97) = -0.124, 95% CI [-0.129, -0.119], p < 0.0005); cognitive function, r_s (97) = -0.018, 95% CI [-0.023, -0.013], p < 0.001); and sleep disturbances, r_s (97) = -0.275, 95% CI [-0.280, -0.271], p < 0.0005). Beyond adjusting for social interaction, increased religious attendance was associated with lower NPS, better cognitive function, and fewer sleep disturbances. Clinical trials and longitudinal studies with a larger sample size examining religion and spirituality factors with dementia progression are warranted.

Determinants of Physical Functioning and Health-Related Quality of Life among Sexual and Gender Minority Older Adults with Cognitive Impairment

Objectives: To examine risk and protective factors predicting physical functioning and physical and psychological health-related quality of life (HRQOL) among sexual and gender minority (SGM) older adults with cognitive impairment. Methods: This study analyzed longitudinal data from Aging with Pride: National Health, Aging, and Sexuality/Gender Study with a sub-sample of 855 SGM older adults who reported difficulties in cognitive performance. Results: Physical functioning and HRQOL linearly declined over time, and the decline of physical functioning was steeper for those with low levels of physical and outdoor leisure activities. The overall levels of physical functioning and HRQOL over time were associated with physical and outdoor leisure activities, optimal sleep, and sufficient food intake. HRQOL was negatively associated with lifetime discrimination and victimization, identity stigma, and smaller social network. Discussion: These findings can be used to develop interventions to improve physical functioning and HRQOL of SGM older adults living with cognitive impairment.

Patterns of sleep disturbances across stages of cognitive decline

OBJECTIVES

The purpose of this study was to investigate insomnia symptoms and excessive sleep/sluggishness across stages of cognitive decline (cognitively normal [CN], Cognitively Impairment, Not Demented [CIND], dementia) in a large, racially/ethnically diverse sample of older adults (70+) in the US. We also examined whether sleep disturbances at baseline predicted conversion to CIND or dementia at follow-up.

METHODS

In this secondary analysis of the Aging, Demographics, and Memory Study (ADAMS) supplement of the Health Retirement Study, we analyzed patterns of informant-reported insomnia and excessive sleep symptoms among three groups of older adults (n = 846): CN, CIND, and dementia.

RESULTS

CIND adults were significantly more likely to have informant-reported insomnia symptoms than those in the CN group (p = 0.013). This was driven by a significant race/ethnicity-by-insomnia interaction with diagnostic status (p = 0.029), such that CIND Black and Hispanic older adults had increased insomnia symptom rates compared to CN, whereas White adults had similar insomnia symptoms across diagnostic status. Across all racial/ethnic groups, the prevalence of excessive sleep symptoms increased stepwise from CN to CIND to dementia (p < 0.001). Overall, insomnia symptoms at baseline predicted conversion from CN to CIND (p < 0.001, OR = 0.288; 95% CI: 0.143-0.580) at 4-year (approximate) follow-up; there was no relationship between baseline insomnia or excessive sleep/sluggishness symptoms and conversion from CIND to dementia.

DISCUSSION/CONCLUSION

This study provides evidence for the increased risk of insomnia symptoms among Hispanic and Black older adults with CIND, and indicates that insomnia symptoms may be associated with increased risk for development of cognitive impairment.

Multi-Component Interventions in Older Adults Having Subjective Cognitive Decline (SCD)-A Review Article

Subjective cognitive decline (SCD) is one of those significant concerns faced by older individuals. Though it is predominantly self-reported, it is not an event that should be overlooked, considering its significant association with cognitive disorders like Alzheimer's disease, mild cognitive impairment, and so on. This makes it imperative to find ways to manage the event to enhance the cognitive performance of older adults and/or suppress the rate at which cognitive decline results in impairment. While multiple interventions have been used for SCD, multi-component non-pharmacological interventions are beginning to gain more attention among researchers. This is due to how such interventions have effectively contributed to improved cognitive performance across different outcome domains. Against this backdrop, this literature review has been conducted to explore the different multi-component non-pharmacological interventions utilized in managing SCD. Papers from databases such as PubMed, Scopus, and EBSCO were retrieved, with relevant data being extracted on the subject matter to address the objective of this review.

Sexual Dimorphism in Neurodegenerative Diseases and in Brain Ischemia

Epidemiological studies and clinical observations show evidence of sexual dimorphism in brain responses to several neurological conditions. It is suggested that sex-related differences between men and women may have profound effects on disease susceptibility, pathophysiology, and progression. Sexual differences of the brain are achieved through the complex interplay of several factors contributing to this phenomenon, such as sex hormones, as well as genetic and epigenetic differences. Despite recent advances, the precise link between these factors and brain disorders is incompletely understood. This review aims to briefly outline the most relevant aspects that differ between men and women in ischemia and neurodegenerative disorders (AD, PD, HD, ALS, and SM). Recognition of disparities between both sexes could aid the development of individual approaches to ameliorate or slow the progression of intractable disorders.

Interactions between the apolipoprotein E4 gene and modifiable risk factors for cognitive impairment: a nationally representative panel study

BACKGROUND

Few studies using rigorous clinical diagnosis have considered whether associations with cognitive decline are potentiated by interactions between genetic and modifiable risk factors. Given the increasing burden of cognitive impairment (CI) and dementia, we assessed whether Apolipoprotein E ε4 (APOE4) genotype status modifies the association between incident CI and key modifiable risk factors .

METHODS

Older adults (70+) in the US were included. APOE4 status was genotyped. Risk factors for CI were self-reported. Cognitive status (normal, CI, or dementia) was assigned by clinical consensus panel. In eight separate Cox proportional hazard models, we assessed for interactions between APOE4 status and other CI risk factors.

RESULT

The analytical sample included 181 participants (mean age 77.7 years; 45.9% male). APOE4 was independently associated with a greater hazard of CI in each model (Hazard Ratios [HR] between 1.81-2.66, p < 0.05) except the model evaluating educational attainment (HR 1.65, p = 0.40). The joint effects of APOE4 and high school education or less (HR 2.25, 95% CI: 1.40-3.60, p < 0.001), hypertension (HR 2.46, 95% CI: 1.28-4.73, p = 0.007), elevated depressive symptoms (HR 5.09, 95% CI: 2.59-10.02, p < 0.001), hearing loss (HR 3.44, 95% CI: 1.87-6.33, p < 0.0001), vision impairment (HR 5.14, 95% CI: 2.31-11.43, p < 0.001), smoking (HR 2.35, 95% CI: 1.24-4.47, p = 0.009), or obesity (HR 3.80, 95% CI: 2.11-6.85, p < 0.001) were associated with the hazard of incident CIND (compared to no genetic or modifiable risk factor) in separate models. The joint effect of Apolipoprotein ε4 and type 2 diabetes was not associated with CIND (HR 1.58, 95% CI: 0.67-2.48, p = 0.44).

DISCUSSION

The combination of APOE4 and selected modifiable risk factors conveys a stronger association with incident CI than either type of risk factor alone.

Associations of five obesity indicators with cognitive performance in 30,697 Taiwan Biobank participants

Background

Obesity adversely influences the central nervous system and cognitive functions. However, the relationship between various obesity indicators and cognitive performance remains controversial. It is unclear which obesity indicator is more relevant to cognitive impairment.

Methods

The Taiwan Biobank (TWB) administered the Chinese version of the Mini-Mental State Examination (MMSE) to 30,697 participants (12,094 males and 18,603 females) aged 60 to 70 years. A total of 3,454 (11.25%) individuals with MMSE < = 24 were classified as having poor cognitive performance. This cross-sectional study investigates the associations of five obesity indicators with cognitive performance. Five separate logistic regression models were fitted for males and another five for females. Covariates adjusted in all models included age, smoking status, drinking status, regular exercise, chronic disease status (diabetes, cardiovascular diseases, heart diseases, stroke, or Parkinson’s disease), depression status, blood pressure level, total cholesterol, fasting glucose, and educational attainment. The five obesity indicators included body mass index (BMI), body fat percentage (BFP), waist circumference (WC), hip circumference (HC), and waist-hip ratio (WHR).

Results

Abdominal obesity defined by WHR was significantly associated with poor cognitive performance. Male WHR > = 0.90 had a higher risk of poor cognitive performance than male WHR < 0.90 (odds ratio [OR] = 1.233; p = 0.007); female WHR > = 0.85 had an increased risk of poor cognitive performance compared with female WHR < 0.85 (OR = 1.221; p = 3.9E-4). HC and general obesity (defined by BMI and BFP) were not significantly associated with cognitive performance.

Conclusion

The results consistently agreed that preventing abdominal obesity is associated with better cognitive performance in both males and females.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03457-x.

Linking Puberty and the Gut Microbiome to the Pathogenesis of Neurodegenerative Disorders

Puberty is a critical period of development marked by the maturation of the central nervous system, immune system, and hypothalamic-pituitary-adrenal axis. Due to the maturation of these fundamental systems, this is a period of development that is particularly sensitive to stressors, increasing susceptibility to neurodevelopmental and neurodegenerative disorders later in life. The gut microbiome plays a critical role in the regulation of stress and immune responses, and gut dysbiosis has been implicated in the development of neurodevelopmental and neurodegenerative disorders. The purpose of this review is to summarize the current knowledge about puberty, neurodegeneration, and the gut microbiome. We also examine the consequences of pubertal exposure to stress and gut dysbiosis on the development of neurodevelopmental and neurodegenerative disorders. Understanding how alterations to the gut microbiome, particularly during critical periods of development (i.e., puberty), influence the pathogenesis of these disorders may allow for the development of therapeutic strategies to prevent them.

Age Profiles of Cognitive Decline and Dementia in Late Life in the Aging, Demographics, and Memory Study

OBJECTIVES

To better understand the temporal dynamics of progression from cognitive decline to onset of dementia in the dementia-free older population in the United States.

METHODS

We used longitudinal data from a diverse national population-based sample of older adults (N = 531) in the Aging, Demographics, and Memory Study from the Health and Retirement Study with repeated measures of cognitive function and dementia diagnosis during 12 years of follow-up from 1996 to 2009. We employed joint latent class mixed models to estimate the association between cognitive change and competing risks of dementia and nondementia death and identify heterogeneity in the age profiles of such association adjusting for baseline characteristics.

RESULTS

Our analyses found 3 latent classes with distinct age profiles of cognitive decline and associated risk of dementia and mortality: "Rapid Cognitive Decline" (19.6%), "Moderate Progression" (44.6%), and "Optimal Cognitive Aging" (35.8%). When simultaneously accounting for cognitive trajectories and time-to-dementia/death, we also found associations of baseline covariates with slope of cognitive decline (e.g., steeper decline among non-Hispanic Blacks and more educated) and risk of dementia (e.g., greater risk for females and apolipoprotein E-4 carriers, but no difference by education level) that differ substantially from those in separate longitudinal mixed models or survival models.

DISCUSSION

The differential age patterns of cognitive decline predicting dementia incidences identified in this study suggest variation in the course of cognitive aging in older adults that may inform future etiological and intervention studies.

The link between cutaneous inflammation and cognitive impairment

Cognitive impairment is a symptom of neurological disorders, including dementia and Alzheimer's disease; and mild cognitive impairment can be a precursor of both disorders. Aged humans and animal models with other systemic disorders, such as cardiovascular diseases and diabetes, display a higher incidence of cognitive decline. Epidemiological studies have shown that the incidence of cognitive impairment also is higher in subjects with certain inflammatory skin disorders, including psoriasis and chronic eczematous dermatitis. Chronologically aged individuals exhibit increased cutaneous inflammation and elevated circulating cytokine levels, linked to alterations in epidermal function, which itself can induce cutaneous inflammation. Conversely, strategies that improve epidermal function can lower cytokine levels in both the skin and circulation. Thus, it seems likely that epidermal dysfunction could contribute, at least in part, to the development of chronic low-grade inflammation, also termed 'inflammaging', in the elderly. The evidence of cognitive impairment in patients with inflammatory dermatoses suggests a link between cutaneous inflammation and cognitive impairment. Because of the pathogenic role of epidermal dysfunction in ageing-associated cutaneous inflammation, improvements in epidermal function could be an alternative approach for mitigation of the ageing-associated decline in cognitive function.

Pharmacotherapeutic potential of pomegranate in age-related neurological disorders

Age-related neurological disorders [AND] include neurodegenerative diseases [NDDs] such as Alzheimer's disease [AD] and Parkinson's disease [PD], which are the most prevalent types of dementia in the elderly. It also includes other illnesses such as migraine and epilepsy. ANDs are multifactorial, but aging is their major risk factor. The most frequent and vital pathological features of AND are oxidative stress, inflammation, and accumulation of misfolded proteins. As AND brain damage is a significant public health burden and its incidence is increasing, much has been done to overcome it. Pomegranate (Punica granatum L.) is one of the polyphenol-rich fruits that is widely mentioned in medical folklore. Pomegranate is commonly used to treat common disorders such as diarrhea, abdominal pain, wound healing, bleeding, dysentery, acidosis, microbial infections, infectious and noninfectious respiratory diseases, and neurological disorders. In the current review article, we aimed to summarize the data on the pharmacotherapeutic potentials of pomegranate in ANDs.

Prevalence of cognitive impairment in Brazilian indigenous community from Amazonas

ABSTRACT. Studies on the prevalence of dementia in the indigenous population are still scarce worldwide. In the few available studies, prevalence evidence varies from low to very high, with early onset of the disease and high mortality rate after the initial diagnosis. Still, little is known about the rate of dementia in indigenous populations from low- and middle-income countries, where the dementia prevalence in the general population is estimated to increase significantly in the next decades. Objective: This study aimed to determine the prevalence of cognitive impairment and associated factors in Brazilian indigenous people of the Mura ethnicity in Amazonas, Brazil. Methods: A total of 217 indigenous individuals aged 50 years and older from Amazonas, Brazil, were submitted to cognitive assessment. Attention, memory, verbal fluency, visuospatial performance, and mood state composed the cognitive impairment diagnosis. Results: The prevalence of cognitive impairment was 43.3% (95%CI 36.6-49.7) and varied according to age [OR=1.03 (95%CI 1.00-1.06)], education [OR=0.74 (95%CI 0.62-0.87)], body mass index [OR=0.91 (95%CI 0.83-0.98)], and income [OR=0.52 (95%CI 0.27-0.99)]. Conclusions: Cognitive impairment had an early onset in an indigenous community, and its prevalence was greater in older individuals with low education and low family income. These findings highlight the importance of implementing public indigenous health policies focusing on health professional training for early cognitive impairment detection.

Alzheimer's disease biomarkers in Black and non-Hispanic White cohorts: A contextualized review of the evidence

Black Americans are disproportionately affected by dementia. To expand our understanding of mechanisms of this disparity, we look to Alzheimer's disease (AD) biomarkers. In this review, we summarize current data, comparing the few studies presenting these findings. Further, we contextualize the data using two influential frameworks: the National Institute on Aging-Alzheimer's Association (NIA-AA) Research Framework and NIA's Health Disparities Research Framework. The NIA-AA Research Framework provides a biological definition of AD that can be measured in vivo. However, current cut-points for determining pathological versus non-pathological status were developed using predominantly White cohorts-a serious limitation. The NIA's Health Disparities Research Framework is used to contextualize findings from studies identifying racial differences in biomarker levels, because studying biomakers in isolation cannot explain or reduce inequities. We offer recommendations to expand study beyond initial reports of racial differences. Specifically, life course experiences associated with racialization and commonly used study enrollment practices may better account for observations than exclusively biological explanations.

Balance on the Brain: a randomised controlled trial evaluating the effect of a multimodal exercise programme on physical performance, falls, quality of life and cognition for people with mild cognitive impairment-study protocol

INTRODUCTION

Exercise and physical activity have been shown to improve cognition for people living with mild cognitive impairment (MCI). There is strong evidence for the benefits of aerobic exercise and medium evidence for participating in regular strength training for people with MCI. However, people living with MCI fall two times as often as those without cognitive impairment and the evidence is currently unknown as to whether balance training for people with MCI is beneficial, as has been demonstrated for older people without cognitive impairment. The aim of this study is to determine whether a balance-focused multimodal exercise intervention improves balance and reduces falls for people with MCI, compared with a control group receiving usual care.

METHODS AND ANALYSIS

This single blind randomised controlled trial (Balance on the Brain) will be offered to 396 people with MCI living in the community. The multimodal exercise intervention consists of two balance programmes and a walking programme to be delivered by physiotherapists over a 6-month intervention period. All participants will be followed up over 12 months (for the intervention group, this involves 6-month intervention and 6-month maintenance). The primary outcomes are (1) balance performance and (2) rate of falls. Physical performance, levels of physical activity and sedentary behaviour, quality of life and cognition are secondary outcomes. A health economic analysis will be undertaken to evaluate the cost-effectiveness of the intervention compared with usual care.

ETHICS AND DISSEMINATION

Ethics approval has been received from the South Metropolitan Health Service Human Research Ethics Committee (HREC), Curtin University HREC and the Western Australia Department of Health HREC; and approval has been received to obtain data for health costings from Services Australia. The results will be disseminated through peer-review publications, conference presentations and online platforms.

TRIAL REGISTRATION NUMBER

ACTRN12620001037998; Australian New Zealand Clinical Trials Registry (ANZCTR).

Physical inactivity in older adults with cognitive impairment without dementia: room for improvement

BACKGROUND

Persons with cognitive impairment without dementia are at high risk of adverse health outcomes. Tailored intervention targeting moderate-vigorous physical activity (MVPA) may reduce these risks.

AIMS

To identify the prevalence and predictors of physical inactivity among older adults with cognitive impairment, no dementia (CIND); and estimate the proportion of inactive people with CIND who are capable of greater MVPA.

METHODS

We studied 1875 community dwelling participants (over age 65) with CIND in the Health and Retirement Study. Physical inactivity was defined as MVPA ≤ 1x/week. Associations of physical inactivity with sociodemographic, health, and physical function were examined using chi-square and modified Poisson regression. We considered physically inactive participants capable of greater MVPA if they reported MVPA at least 1-3x/month, no difficulty walking several blocks, or no difficulty climbing several flights of stairs.

RESULTS

Fifty-six percent of participants with CIND were physically inactive. Variables with the highest age, sex, and race/ethnicity adjusted risk ratio (ARR) for physical inactivity were self-rated health (poor [76.9%]vs. excellent [34.2%]; ARR [95% CI] 2.27 [1.56-3.30]), difficulty walking (across the room [86.5%] vs. none [40.5%]; ARR [95% CI] 2.09 [1.87-2.35]), total assets (lowest quartile [62.6%] vs. highest quartile [43.1%]; ARR [95% CI] 1.54 [1.29-1.83]), and lower education attainment (less than high school [59.6%] vs college graduate [42.8%]; ARR [95% CI] 1.46 [1.17-1.83]). Among physically inactive older adults with CIND, 61% were estimated to be capable of greater MVPA.

CONCLUSIONS

Although physical inactivity is prevalent among older adults with CIND, many are capable of greater MVPA. Developing tailored physical activity interventions for this vulnerable population may improve cognitive, health, and quality of life outcomes.

Dysmetabolism and Neurodegeneration: Trick or Treat?

Accumulating evidence suggests the existence of a strong link between metabolic syndrome and neurodegeneration. Indeed, epidemiologic studies have described solid associations between metabolic syndrome and neurodegeneration, whereas animal models contributed for the clarification of the mechanistic underlying the complex relationships between these conditions, having the development of an insulin resistance state a pivotal role in this relationship. Herein, we review in a concise manner the association between metabolic syndrome and neurodegeneration. We start by providing concepts regarding the role of insulin and insulin signaling pathways as well as the pathophysiological mechanisms that are in the genesis of metabolic diseases. Then, we focus on the role of insulin in the brain, with special attention to its function in the regulation of brain glucose metabolism, feeding, and cognition. Moreover, we extensively report on the association between neurodegeneration and metabolic diseases, with a particular emphasis on the evidence observed in animal models of dysmetabolism induced by hypercaloric diets. We also debate on strategies to prevent and/or delay neurodegeneration through the normalization of whole-body glucose homeostasis, particularly via the modulation of the carotid bodies, organs known to be key in connecting the periphery with the brain.

Body Mass Index and Memory Across 18 Years in the Wisconsin Longitudinal Study

BACKGROUND

Body weight is a modifiable risk factor for dementia, but results have been mixed as to the ages at which normal body weight is markedly preferable to overweight or obesity. This study assessed the association between change in body mass index (BMI) over 2 periods of the life course with change in memory between the ages of 65 and 72 for males and females.

METHODS

Participants were 3 637 White high school graduates, born in 1939, from the Wisconsin Longitudinal Study. The statistical analyses were fixed-effects regression models, with moderation terms to test for sex differences. One set of models examined change in BMI between ages 54 and 65, and the other set examined change in BMI between ages 65 and 72. In both cases, cognitive change occurred between ages 65 and 72.

RESULTS

Greater increases in BMI were associated with a greater decline in immediate recall for females only, both contemporaneously and following a lag. Increases in BMI were associated with greater contemporaneous-but not lagged-declines in both delayed recall and digit ordering for both males and females.

CONCLUSIONS

The present study adds to the evidence that for White, high school educated Americans, weight gain in midlife and young-old age is a risk factor for memory decline. Results vary according to the timing of the weight gain, the aspect of memory measured, and participant sex.

Long-term associations between amyloid positron emission tomography, sex, apolipoprotein E and incident dementia and mortality among individuals without dementia: hazard ratios and absolute risk

Dementia and mortality rates rise inexorably with age and consequently interact. However, because of the major logistical difficulties in accounting for both outcomes in a defined population, very little work has examined how risk factors and biomarkers for incident dementia are influenced by competing mortality. The objective of this study was to examine long-term associations between amyloid PET, APOE ɛ4, sex, education and cardiovascular/metabolic conditions, and hazard and absolute risk of dementia and mortality in individuals without dementia at enrolment. Participants were enrolled in the Mayo Clinic Study of Aging, a population-based study of cognitive ageing in Olmsted County, MN, USA. All were without dementia and were age 55-92 years at enrolment and were followed longitudinally. Predictor variables were amyloid PET, APOE ɛ4 status, sex, education, cardiovascular/metabolic conditions and age. The main outcomes were incident dementia and mortality. Multivariable, multi-state models were used to estimate mortality and incident dementia rates and absolute risk of dementia and mortality by predictor variable group. Of the 4984 participants in the study, 4336 (87%) were cognitively unimpaired and 648 (13%) had mild cognitive impairment at enrolment. The median age at enrolment was 75 years; 2463 (49%) were women. The median follow-up time was 9.4 years (7.5 years after PET). High versus normal amyloid (hazard ratio 2.11, 95% confidence interval 1.43-2.79), APOE ɛ4 (women: hazard ratio 2.24, 95% confidence interval 1.80-2.77; men: hazard ratio 1.37, 95% confidence interval 1.09-1.71), older age and two additional cardiovascular/metabolic conditions (hazard ratio 1.37, 95% confidence interval 1.22-1.53) were associated with the increased hazard of dementia (all P < 0.001). Among APOE ɛ4 carriers with elevated amyloid, remaining lifetime risk of dementia at age 65 years was greater in women [74% (95% confidence interval 65-84%) high and 58% (95% confidence interval 52-65%) moderate amyloid], than men [62% (95% confidence interval 52-73%) high and 44% (95% confidence interval 35-53%) moderate amyloid]. Overall, the hazard and absolute risk of dementia varied considerably by predictor group. The absolute risk of dementia associated with predictors characteristic of Alzheimer's disease was greater in women than men while at the same time the combination of APOE ɛ4 non-carrier with normal amyloid was more protective in women than men. This set of findings may be attributed in part to different biological effects and in part to lower mortality rates in women.

Air pollution as a risk factor for Cognitive Impairment no Dementia (CIND) and its progression to dementia: A longitudinal study

BACKGROUND AND AIM

Accumulation of evidence has raised concern regarding the harmful effect of air pollution on cognitive function, but results are diverging. We aimed to investigate the longitudinal association of long-term exposure to air pollutants and cognitive impairment and its further progression to dementia in older adults residing in an urban area.

METHODS

Data were obtained from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). Cognitive impairment, no dementia (CIND) was assessed by a comprehensive neuropsychological battery (scoring ≥1.5 standard deviations below age-specific means in ≥1 cognitive domain). We assessed long-term residential exposure to particulate matters (PM_2.5 and PM₁₀) and nitrogen oxides (NO_x) with dispersion modeling. The association with CIND was estimated using Cox proportional hazards models with 3-year moving average air pollution exposure. We further estimated the effect of long-term air pollution exposure on the progression of CIND to dementia using Cox proportional hazards models.

RESULTS

Among 1987 cognitively intact participants, 301 individuals developed CIND during the 12-year follow-up. A 1-μg/m³ increment in PM_2.5 exposure was associated with a 75% increased risk of incident CIND (HR = 1.75, 95 %CI: 1.54, 1.99). Weaker associations were found for PM₁₀ (HR for 1-μg/m³ = 1.08, 95 %CI: 1.03-1.14) and NO_x (HR for 10 μg/m³ = 1.18, 95 %CI: 1.04-1.33). Among those with CIND at baseline (n = 607), 118 participants developed dementia during follow-up. Results also show that exposure to air pollution was a risk factor for the conversion from CIND to dementia (PM_2.5: HR for 1-μg/m³ = 1.90, 95 %CI: 1.48-2.43; PM₁₀: HR for 1-μg/m³ = 1.14, 95 %CI: 1.03-1.26; and NO_x: HR for 10 μg/m³ = 1.34, 95 %CI: 1.07-1.69).

CONCLUSION

We found evidence of an association between long-term exposure to ambient air pollutants and incidence of CIND. Of special interest is that air pollution also was a risk factor for the progression from CIND to dementia.

Myrtenal mitigates streptozotocin-induced spatial memory deficit via improving oxido inflammatory, cholinergic and neurotransmitter functions in mice

The occurrence of chronic neurodegenerative disorders is on the rise, but with no effective treatment due to the paucity of information on the pathological mechanism underlying these disorders. Thus, this study investigated the role of oral administration of myrtenal in mitigating memory deficits and neuro-biochemical alterations in streptozotocin-demented mice model. Mice (n ​= ​35) were randomly allocated into five cohorts consisting of 7 mice each; Group I: Control mice received vehicle alone; Group II: streptozotocin; Group III: streptozotocin + 100 ​mg/kg myrtenal; Group IV: streptozotocin +200 ​mg/kg myrtenal; and Group V: streptozotocin ​+ ​donepezil 0.5 ​mg/kg. Data from this study demonstrated that the administration of streptozotocin (STZ) impaired spatial memory and induced alterations in markers of oxido-inflammatory response, cholinergic function, cytoarchitecture, and neurotransmitter levels in mice hippocampus. Notably, administration of myrtenal enhanced spatial memory performance in STZ-demented mice by improving the activities of endogenous antioxidant enzymes to protect the brain from oxido-inflammatory stress. Treatment with myrtenal also restored cholinergic function and stabilized the homeostasis of neurotransmitters in STZ-demented mice. The authors infer that fruits rich in myrtenal may be beneficial for treating patients living with dementia associated with Alzheimer's disease.

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Data from the present study demonstrates that the administration of streptozotocin impairs spatial memory in mice and induces alterations in markers of oxido-inflammatory response, cholinergic function, histoarchitecture, and neurotransmitter levels in the hippocampus.

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The administration of myrtenal enhances spatial memory performance in streptozotocin-demented mice by improving the activities of endogenous antioxidant enzymes to protect the brain from oxido-inflammatory stress.

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Treatment with myrtenal restores cholinergic function and stabilizes the homeostasis of neurotransmitters in streptozotocin-demented mice.

Neuroimmune contributions to Alzheimer's disease: a focus on human data

The past decade has seen the convergence of a series of new insights that arose from genetic and systems analyses of Alzheimer's disease (AD) with a wealth of epidemiological data from a variety of fields; this resulted in renewed interest in immune responses as important, potentially causal components of AD. Here, we focus primarily on a review of human data which has recently yielded a set of robust, reproducible results that exist in a much larger universe of conflicting reports stemming from small studies with important limitations in their study design. Thus, we are at an important crossroads in efforts to first understand at which step of the long, multiphasic course of AD a given immune response may play a causal role and then modulate this response to slow or block the pathophysiology of AD. We have a wealth of new experimental tools, analysis methods, and capacity to sample human participants at large scale longitudinally; these resources, when coupled to a foundation of reproducible results and novel study designs, will enable us to monitor human immune function in the CNS at the level of complexity that is required while simultaneously capturing the state of the peripheral immune system. This integration of peripheral and central perturbations in immune responses results in pathologic responses in the central nervous system parenchyma where specialized cellular microenvironments composed of multiple cell subtypes respond to these immune perturbations as well as to environmental exposures, comorbidities and the impact of the advancing life course. Here, we offer an overview that seeks to illustrate the large number of interconnecting factors that ultimately yield the neuroimmune component of AD.

Prevalence, Incidence, and Progression of Cognitive Impairment, No Dementia Among Rural-Dwelling Chinese Older Adults

BACKGROUND

Few studies have examined occurrence and progression of cognitive impairment, no dementia (CIND) in rural China.

OBJECTIVE

To determine the prevalence and incidence of CIND in rural-dwelling Chinese older adults, and to examine risk and protective factors associated with progression to CIND and dementia.

METHODS

This population-based study included 2,781 dementia-free participants (age≥65 years) who were examined at baseline (2014) and followed in 2018. Demographic, epidemiological, clinical, and neuropsychological data were collected following a structured questionnaire. We defined CIND according to subjective cognitive complaints and the age- and education-specific Mini-Mental State Examination (MMSE) score. Data were analyzed with the multinomial logistic regression models.

RESULTS

The overall prevalence of CIND was 10.54% and the incidence was 28.26 per 1,000 person-years. CIND at baseline was associated with the multi-adjusted odds ratio (OR) of 2.06 (95% confidence interval = 1.23-3.47) for incident dementia. Multinomial logistic regression analysis suggested that compared with no CIND, the multi-adjusted OR of incident CIND was 2.21 (1.51-3.23) for women and 0.62 (0.38-0.99) for high social support, whereas the multi-adjusted OR of incident dementia was 1.14 (1.09-1.18) for older age, 0.29 (0.16-0.53) for high education, and 2.91 (1.47-5.74) for having a stroke history.

CONCLUSION

CIND affects over one-tenth of older adults living in rural communities of western Shandong province. People with CIND are twice as likely to progress to dementia as people without CIND. Female sex, low education, stroke history, and low social support are associated with an increased risk of progression from normal cognition to CIND or dementia.

Metabolic determinants of Alzheimer's disease: A focus on thermoregulation

Alzheimer's disease (AD) is a complex age-related neurodegenerative disease, associated with central and peripheral metabolic anomalies, such as impaired glucose utilization and insulin resistance. These observations led to a considerable interest not only in lifestyle-related interventions, but also in repurposing insulin and other anti-diabetic drugs to prevent or treat dementia. Body temperature is the oldest known metabolic readout and mechanisms underlying its maintenance fail in the elderly, when the incidence of AD rises. This raises the possibility that an age-associated thermoregulatory deficit contributes to energy failure underlying AD pathogenesis. Brown adipose tissue (BAT) plays a central role in thermogenesis and maintenance of body temperature. In recent years, the modulation of BAT activity has been increasingly demonstrated to regulate energy expenditure, insulin sensitivity and glucose utilization, which could also provide benefits for AD. Here, we review the evidence linking thermoregulation, BAT and insulin-related metabolic defects with AD, and we propose mechanisms through which correcting thermoregulatory impairments could slow the progression and delay the onset of AD.

The Longitudinal Association of Vision Impairment With Transitions to Cognitive Impairment and Dementia: Findings From the Aging, Demographics and Memory Study

BACKGROUND

Vision impairment (VI) is associated with incident cognitive decline and dementia. However, it is not known whether VI is associated only with the transition to cognitive impairment, or whether it is also associated with later transitions to dementia.

METHODS

We used data from the population-based Aging, Demographics and Memory Study (ADAMS) to investigate the association of visual acuity impairment (VI; defined as binocular presenting visual acuity <20/40) with transitions from cognitively normal to cognitive impairment no dementia (CIND) and from CIND to dementia. Multivariable Cox proportional hazards models and logistic regression were used to model the association of VI with cognitive transitions, adjusted for covariates.

RESULTS

There were 351 participants included in this study (weighted percentages: 45% male, 64% age 70-79 years) with a mean follow-up time of 4.1 years. In a multivariable model, the hazard of dementia was elevated among those with VI (hazard ratio = 1.63, 95% confidence interval = 1.04-2.58). Participants with VI had a greater hazard of transitioning from cognitively normal to CIND (hazard ratio = 1.86, 95% confidence interval = 1.09-3.18). However, among those with CIND and VI a similar percentage transitioned to dementia (48%) and remained CIND (52%); there was no significant association between VI and transitioning from CIND to dementia (hazard ratio = 0.94, 95% confidence interval = 0.56-1.55). Using logistic regression models, the same associations between VI and cognitive transitions were identified.

CONCLUSIONS

Poor vision is associated with the development of CIND. The association of VI and dementia appears to be due to the higher risk of dementia among individuals with CIND. Findings may inform the design of future interventional studies.

The cognitive effect of anticholinergics for patients with overactive bladder

Overactive bladder (OAB) is often treated with medications that block the cholinergic receptors in the bladder (known as anticholinergics). The effect of this medication class on cognition and risk of dementia has been increasingly studied over the past 40 years after initial studies suggested that the anticholinergic medication class could affect memory. Short-term randomized clinical trials demonstrated that the administration of the anticholinergic oxybutynin leads to impaired memory and attention, and large, population-based studies showed associations between several different anticholinergic medications and dementia. However, trials involving anticholinergics other than oxybutynin have not shown such substantial effects on short-term cognitive function. This discordance in results between short-term cognitive safety of OAB anticholinergics and the long-term increased dementia risk could be explained by the high proportion of patients using oxybutynin in the OAB subgroups of the dementia studies, or a study duration that was too short in the prospective clinical trials on cognition with other OAB anticholinergics. Notably, all studies must be interpreted in the context of potential confounding factors, such as when prodromal urinary symptoms associated with the early stages of dementia lead to an increase in OAB medication use, rather than the use of OAB medication causing dementia. In patients with potential risk factors for cognitive impairment, the cautious use of selected OAB anticholinergic agents with favourable physicochemical and pharmacokinetic properties and clinical trial evidence of cognitive safety might be appropriate.

Racial/Ethnic Disparities in Alzheimer's Disease Risk: Role of Exposure to Ambient Fine Particles

BACKGROUND

Whether racial/ethnic disparities in Alzheimer's disease (AD) risk may be explained by ambient fine particles (PM2.5) has not been studied.

METHOD

We conducted a prospective, population-based study on a cohort of Black (n = 481) and White (n = 6 004) older women (aged 65-79) without dementia at enrollment (1995-1998). Cox models accounting for competing risk were used to estimate the hazard ratio (HR) for racial/ethnic disparities in AD (1996-2010) defined by Diagnostic and Statistical Manual of Mental Disorders, 4th edition and the association with time-varying annual average PM2.5 (1999-2010) estimated by spatiotemporal model.

RESULTS

Over an average follow-up of 8.3 (±3.5) years with 158 incident cases (21 in Black women), the racial disparities in AD risk (range of adjusted HRBlack women = 1.85-2.41) observed in various models could not be explained by geographic region, age, socioeconomic characteristics, lifestyle factors, cardiovascular risk factors, and hormone therapy assignment. Estimated PM2.5 exposure was higher in Black (14.38 ± 2.21 µg/m3) than in White (12.55 ± 2.76 µg/m3) women, and further adjustment for the association between PM2.5 and AD (adjusted HRPM2.5 = 1.18-1.28) slightly reduced the racial disparities by 2%-6% (HRBlack women = 1.81-2.26). The observed association between PM2.5 and AD risk was ~2 times greater in Black (HRPM2.5 = 2.10-2.60) than in White (HRPM2.5 = 1.07-1.15) women (range of interaction ps: <.01-.01). We found similar results after further adjusting for social engagement (social strain, social support, social activity, living alone), stressful life events, Women's Health Initiative's clinic sites, and neighborhood socioeconomic characteristics.

CONCLUSIONS

PM2.5 may contribute to racial/ethnic disparities in AD risk and its associated increase in AD risk was stronger among Black women.

Improvement of Cognitive Function and Interleukin 1 Beta Serum Concentrations Following Cardiac Pacemaker Implantation in Patients with Symptomatic Bradycardia

Background and aim: Bradyarrhythmias cause a low cerebral blood flow with secondary neuronal ischemia and cognitive dysfunction. This study aims to assess the effect of cardiac pacemaker implantation (PI) on the cognitive function and inflammatory markers (TNF alpha, IL1β). Material and method: We conducted a prospective observational study on a number of 31 patients with symptomatic bradyarrhythmias. We performed the cognitive function assessment by two tests (Mini-Mental State Examination and Trail Making Test A), cardiac output assessment (echocardiographic), and determination of IL 1β and TNF alpha serum concentrations before pacemaker implantation and after an average period of 42 days from pacemaker implantation.Results: After pacemaker implantation we observed an increase in the cardiac index by 0.71 L/min/m² (p < 0.001) and a better scoring in cognitive performance; the mean MMSE score increased by two points (p < 0.001), and Trail Making Test A had an improvement of 16 s (p < 0.001). Regarding the inflammatory markers, a significant decrease in IL-1β with 8.6 pg/mL (p = 0.049) after pacemaker implantation was observed. Additionally, we found statistically significant correlations between IL1β and TNF alpha (positive correlation, p = 0.005), between the MMSE and cardiac index (p < 0.001), between the Trail Making Test and cardiac index (p = 0.001), and between the MMSE and Trail Making Test (p = 0.003). Conclusions: Our findings suggest that cardiac pacemaker implantation was associated with improved cognitive function—possibly related to an increased cardiac output and with adecreased serum IL1β concentration in subjects with symptomatic bradycardia.