Healthy Lifestyle and Cognition in Older Adults With Common Neuropathologies of Dementia

Importance

A healthy lifestyle is associated with better cognitive functioning in older adults, but whether this association is independent of the accumulation of dementia-related pathologies in the brain is uncertain.

Objective

To determine the role of postmortem brain pathology, including β-amyloid load, phosphorylated tau tangles, cerebrovascular pathology, and other brain pathologies, in the association between lifestyle and cognition proximate to death.

Design, Setting, and Participants

This cohort study used data from the Rush Memory and Aging Project, a longitudinal clinical-pathologic study with autopsy data from 1997 to 2022 and up to 24 years of follow-up. Participants included 754 deceased individuals with data on lifestyle factors, cognitive testing proximate to death, and a complete neuropathologic evaluation at the time of these analyses. Data were analyzed from January 2023 to June 2023.

Exposures

A healthy lifestyle score was developed based on self-reported factors, including noncurrent smoking, at least 150 minutes of physical activity per week, limiting alcohol consumption, a Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet score higher than 7.5, and a late-life cognitive activity score higher than 3.2. The lifestyle score ranges from 0 to 5, with higher scores reflecting a healthier lifestyle.

Main Outcomes and Measures

The global cognitive score was derived from a battery of nineteen standardized tests. Brain pathology measures included β-amyloid load, phosphorylated tau tangles, global Alzheimer disease pathology, vascular brain pathologies, Lewy body, hippocampal sclerosis, and TAR DNA-binding protein 43.

Results

Of 586 included decedents, 415 (70.8%) were female, 171 (29.2%) were male, and the mean (SD) age at death was 90.9 (6.0) years. Higher lifestyle score was associated with better global cognitive functioning proximate to death. In the multivariable-adjusted model, a 1-point increase in lifestyle score was associated with 0.216 (SE = 0.036, P < .001) units higher in global cognitive scores. Neither the strength nor the significance of the association changed substantially when common dementia-related brain pathologies were included in the multivariable-adjusted models. The β estimate after controlling for the β-amyloid load was 0.191 (SE = 0.035; P < .001). A higher lifestyle score was associated with lower β-amyloid load in the brain (β = -0.120; SE = 0.041; P = .003), and 11.6% of the lifestyle-cognition association was estimated through β-amyloid load.

Conclusions and Relevance

This study found that in older adults, a healthy lifestyle may provide a cognitive reserve to maintain cognitive abilities independently of common neuropathologies of dementia.

Trial of the MIND Diet for Prevention of Cognitive Decline in Older Persons

BACKGROUND

Findings from observational studies suggest that dietary patterns may offer protective benefits against cognitive decline, but data from clinical trials are limited. The Mediterranean-DASH Intervention for Neurodegenerative Delay, known as the MIND diet, is a hybrid of the Mediterranean diet and the DASH (Dietary Approaches to Stop Hypertension) diet, with modifications to include foods that have been putatively associated with a decreased risk of dementia.

METHODS

We performed a two-site, randomized, controlled trial involving older adults without cognitive impairment but with a family history of dementia, a body-mass index (the weight in kilograms divided by the square of the height in meters) greater than 25, and a suboptimal diet, as determined by means of a 14-item questionnaire, to test the cognitive effects of the MIND diet with mild caloric restriction as compared with a control diet with mild caloric restriction. We assigned the participants in a 1:1 ratio to follow the intervention or the control diet for 3 years. All the participants received counseling regarding adherence to their assigned diet plus support to promote weight loss. The primary end point was the change from baseline in a global cognition score and four cognitive domain scores, all of which were derived from a 12-test battery. The raw scores from each test were converted to z scores, which were averaged across all tests to create the global cognition score and across component tests to create the four domain scores; higher scores indicate better cognitive performance. The secondary outcome was the change from baseline in magnetic resonance imaging (MRI)-derived measures of brain characteristics in a nonrandom sample of participants.

RESULTS

A total of 1929 persons underwent screening, and 604 were enrolled; 301 were assigned to the MIND-diet group and 303 to the control-diet group. The trial was completed by 93.4% of the participants. From baseline to year 3, improvements in global cognition scores were observed in both groups, with increases of 0.205 standardized units in the MIND-diet group and 0.170 standardized units in the control-diet group (mean difference, 0.035 standardized units; 95% confidence interval, -0.022 to 0.092; P = 0.23). Changes in white-matter hyperintensities, hippocampal volumes, and total gray- and white-matter volumes on MRI were similar in the two groups.

CONCLUSIONS

Among cognitively unimpaired participants with a family history of dementia, changes in cognition and brain MRI outcomes from baseline to year 3 did not differ significantly between those who followed the MIND diet and those who followed the control diet with mild caloric restriction. (Funded by the National Institute on Aging; ClinicalTrials.gov number, NCT02817074.).

Predicting age at Alzheimer's dementia onset with the cognitive clock

INTRODUCTION

Intervention of Alzheimer's dementia hinges on early diagnosis and advanced planning. This work utilizes the cognitive clock, a novel indicator of brain health, to develop a dementia prediction model that can be easily applied in broad settings.

METHODS

Data came from over 3000 community-dwelling older adults. Cognitive age was estimated by aligning Mini-Mental State Examination (MMSE) scores to a clock that represents the typical cognitive aging profile. We identified a mean cognitive age at Alzheimer's dementia onset and predicted the corresponding chronological age at person-specific level.

RESULTS

The mean chronological age at baseline was 78 years. A total of 881 (28%) participants developed Alzheimer's dementia. The mean cognitive age at onset was 91 years. The predicted chronological age at onset had a mean (standard deviation) of 87.6 (6.7) years. The model's prediction accuracy was supported by multiple testing statistics.

DISCUSSION

Our model offers an easy-to-use tool for predicting person-specific age at Alzheimer's dementia onset.

Sex Differences in Alzheimer's Disease

Reviewing the research presented in this article, it is evident that from an epidemiological perspective, it is important to evaluate the extent to which findings of sex and gender differences in Alzheimer's dementia (AD) are due to differences in longevity, survival bias, and comorbidities. Medical, genetic, psychosocial, and behavioral factors, in addition to hormonal factors, can differentially affect the risk and progression of AD in women versus men. Further, evaluation of sex differences in AD progression and the trajectory of change in cognitive function, neuroimaging, cerebrospinal fluid (CSF), and blood-based biomarkers of AD is needed. Finally, identifying sex differences in AD biomarkers and change across the lifespan is critical for the planning of prevention trials to reduce the risk of developing AD.

Sex and gender considerations in dementia: a call for global research

Studies have identified sex and/or gender differences in Alzheimer’s disease, but few have examined other dementias. We highlight sex and gender differences in other dementias, discuss sociocultural factors and provide a framework for future global studies.

Serum neurofilament light chain, brain infarcts, and the risk of stroke: a prospective population-based cohort study

Neurofilament light chain (NfL), a neuron-specific protein, has been related to several neurodegenerative diseases. In addition, elevated levels of NfL have also been observed in patients admitted to the hospital for stroke, suggesting that NfL as a biomarker may extend well beyond neurodegenerative diseases. Therefore, using data from the Chicago Health and Aging Project (CHAP), a population-based cohort study, we prospectively investigated the association of serum NfL levels with incident stroke and brain infarcts. During a follow-up of 3603 person-years, 133 (16.3%) individuals developed incident stroke, including ischemic and hemorrhagic. The HR (95%CI) of incident stroke was 1.28 (95%CI 1.10-1.50) per 1 standard deviation (SD) increase of log10 NfL serum levels. Compared to participants in the first tertile of NfL (i.e., lower levels), the risk of stroke was 1.68 times higher (95%CI 1.07-2.65) in those in the second tertile and 2.35 times higher (95%CI 1.45-3.81) in those in the third tertile of NfL. NfL levels were also positively associated with brain infarcts; 1-SD in log10 NfL levels was associated with 1.32 (95%CI 1.06-1.66) higher odds of one or more brain infarcts. These results suggest that NfL may serve as a biomarker of stroke in older adults.

Longitudinal Changes in Blood Biomarkers of Clinical Alzheimer Disease in a Biracial Population Sample

BACKGROUND AND OBJECTIVES

Recent studies suggest the utility of blood biomarkers in detecting changes in neurodegenerative disorders. The objective of our research was to test the hypothesis that the longitudinal changes in total tau (t-tau), neurofilament light chain (Nf-L), and glial fibrillary acidic protein (GFAP) are associated with structural MRI and the development of clinical Alzheimer disease (AD) and cognitive decline.

METHODS

Data came from a population-based sample with serum concentrations of t-tau, Nf-L, and GFAP and cognitive characteristics measured over 17 years. The inclusion criteria for this investigation were based on participants with blood samples, cognitive function testing, and clinical diagnosis for AD. The longitudinal changes in the serum biomarkers were examined using linear mixed models for log10-transformed concentrations.

RESULTS

In 1,327 participants (60% Black participants and 60% women, the concentration of t-tau increased annually by 4.8% (95% CI = 4.0-5.6) and Nf-L by 5.9% (95% CI = 5.4-6.4). The longitudinal change in GFAP was higher among Black participants than among White participants (4.4% vs 3.5% per year, p = 0.028). Baseline MRI characteristics were associated with the longitudinal changes in serum biomarkers of clinical AD. Specifically, a higher baseline third ventricular volume was associated with a higher rate of increase in the concentration of t-tau, and white matter hyperintensities predicted a higher rate of increase in Nf-L. The rate of change in concentrations of t-tau, Nf-L, and GFAP was significantly higher among those who developed clinical AD than in those with no cognitive impairment. For each standard deviation unit decline in global cognition, longitudinal change in t-tau increased by 81% (95% CI = 76-86), Nf-L by 113% (95% CI = 105-120), and GFAP by 66% (95% CI = 62-70).

DISCUSSION

Blood biomarkers showed significant longitudinal changes corresponding to cognitive decline, clinical AD, and structural MRI characteristics. Our findings show that longitudinal changes in serum biomarkers were associated with several cognitive endophenotypes.

CLASSIFICATION OF EVIDENCE

The study found Class II evidence that longitudinal changes in serum t-tau, Nf-L, and GFAP were associated with cognitive decline and the development of clinical AD in people older than 65 years.

A Qualitative Examination of Knowledge, Experiences, and Considerations of PET Brain Scan Participation Among Older Black and Latino Adults

BACKGROUND

Biological biomarkers yielded from positron emission tomography (PET) brain scans serve as a pathway to understanding Alzheimer's disease pathology. PET brain scan data remain limited for populations traditionally under-included in aging research.

OBJECTIVE

The purpose of this qualitative study was to examine participant-identified barriers to PET brain scan consent and characterize participant-informed elements of educational materials needed to facilitate PET brain scan participation among older Black and Latino adults.

METHODS

Participants (N = 31) were older adults (mean age = 71 years) who self-identified as either non-Latino Black (n = 15) or Latino (n = 16). Each participant took part in a one-time, in-depth individual interview. Researchers analyzed data guided by a Grounded Theory Approach with both Open Coding and Constant Comparative Coding.

RESULTS

Four overarching themes emerged across all participants: 1) knowledge limitations; 2) requirements for consent; 3) motivators for participation; and 4) social networks. Within the four themes, there were differences based on participant ethnoracial group. For example, for Theme Three, older Black adults indicated that they would expect compensation for PET brain scan participation. Conversely, older Latinos stated that they would appreciate, but not anticipate, a financial incentive. All participants stressed the importance of written educational materials with subsequent verbal discussions with studystaff.

CONCLUSION

Findings inform the development and implementation of scientifically-relevant and culturally-cognizant engagement approaches, educational materials, and recruitment strategies to increase PET brain scan participation by diverse older adults.

Sex-based disparities and in-hospital outcomes of patients hospitalized with atrial fibrillation with and without dementia

Study objective

We sought to evaluate the sex-based disparities and comparative in-hospital outcomes of principal AF hospitalizations in patients with and without dementia, which have not been well-studied.

Design

This is a non-interventional retrospective cohort study.

Setting and participants

We identified principal hospitalizations of AF in the National Inpatient Sample in adults (≥18 years old) between January 2016 and December 2019.

Main outcome measure

In-hospital mortality.

Results

Of 378,230 hospitalized patients with AF, 49.2 % (n = 186,039) were females and 6.1 % (n = 22,904) had dementia. The mean age (SD) was 71 (13) years. Patients with dementia had higher odds of in-hospital mortality {adjusted odds ratio (aOR): 1.48, 95 % confidence interval (CI): 1.34, 1.64, p < 0.001} and nontraumatic intracerebral hemorrhage (aOR: 1.60, 95 % CI: 1.04, 2.47, p = 0.032), but they had lower odds of catheter ablation (0.39, 95 % CI: 0.35, 0.43, p < 0.001) and electrical cardioversion (aOR: 0.33, 95 % CI: 0.31, 0.35, p < 0.001). In patients with AF and dementia, compared to males, females had similar in-hospital mortality (aOR: 1.00, 95 % CI: 0.93, 1.07, p = 0.960), fewer gastrointestinal bleeds (aOR: 0.92, 95 % CI: 0.85, 0.99, p = 0.033), lower odds of getting catheter ablation (aOR: 0.79, 95 % CI: 0.76, 0.81, p < 0.001), and less likelihood of getting electrical cardioversion (aOR: 0.78, 95 % CI: 0.76, 0.79, p < 0.001).

Conclusions

Patients with AF and dementia have higher mortality and a lower likelihood of getting catheter ablation and electrical cardioversion.

Incorporation of concussion history as part of the LIfestyle for BRAin Health (LIBRA) modifiable factors risk score and associations with cognition in older former National Football League players

OBJECTIVE

Investigate associations between the LIfestyle for BRAin Health (LIBRA) risk score with odds of mild cognitive impairment (MCI) diagnosis and cognitive function, incorporating concussion history.

METHODS

Former National Football League (NFL) players (N = 1050; mean age = 64.8 ± 9.0-years) completed initial testing for integration of concussion history into LIBRA scores (i.e., modified-LIBRA) and completed the Brief Test of Adult Cognition by Telephone (BTACT). Modified-LIBRA score (including concussion history) associations with odds of MCI and cognitive dysfunction were assessed via logistic and linear regression.

RESULTS

The highest quartile LIBRA scores were six times more likely to have a diagnosis of MCI compared to the lowest quartile (OR = 6.27[3.61, 10.91], p < 0.001). Modified-LIBRA scores significantly improved model fit for odds of MCI above original LIBRA scores (χ² (1) = 7.76, p = 0.005) and accounted for a greater fraction of variance in executive function (ΔR²  = 0.02, p = 0.003) and episodic memory (ΔR²  = 0.02, p = 0.002).

CONCLUSIONS

Modified-LIBRA score, incorporating concussion history, may help monitoring risk status in former contact sport athletes, by targeting modifiable, lifestyle-related risk factors.

Vascular Cognitive Impairment: A Little Bit of Good News for Women or Bad News for Men?

In a recent issue of the Journal of Alzheimer's Disease, Zinman et al. investigated the role of sex in the risk of cognitive impairment in 5,969 patients with a stroke or transient ischemic attacks. Using a short validated clinical screening tool, they noted that men had a 34% higher risk of screening positive for post-stroke cognitive impairment after adjusting for age, education, and stroke severity compared to women. This study highlights that more large, prospective, and multicenter studies are needed to evaluate sex-specific changes after a stroke since sex differences exist in many aspects of stroke presentation and management.

Consideration of sex and gender in Alzheimer's disease and related disorders from a global perspective

Sex or gender differences in the risk of Alzheimer's disease and related dementias (ADRD) differ by world region, suggesting that there are potentially modifiable risk factors for intervention. However, few epidemiological or clinical ADRD studies examine sex differences; even fewer evaluate gender in the context of ADRD risk. The goals of this perspective are to: (1) provide definitions of gender, biologic sex, and sexual orientation. and the limitations of examining these as binary variables; (2) provide an overview of what is known with regard to sex and gender differences in the risk, prevention, and diagnosis of ADRD; and (3) discuss these sex and gender differences from a global, worldwide perspective. Identifying drivers of sex and gender differences in ADRD throughout the world is a first step in developing interventions unique to each geographical and sociocultural area to reduce these inequities and to ultimately reduce global ADRD risk. HIGHLIGHTS: The burden of dementia is unevenly distributed geographically and by sex and gender. Scientific advances in genetics and biomarkers challenge beliefs that sex is binary. Discrimination against women and sex and gender minority (SGM) populations contributes to cognitive decline. Sociocultural factors lead to gender inequities in Alzheimer's disease and related dementias (ADRD) worldwide.

Including General Audiences in a Virtual Scientific Dementia Conference: Will They Get Anything From It?

BACKGROUND

Study participants, patients, and care partners are key stakeholders in research and have asked for greater inclusion in the dissemination of scientific learning. However, the participation of general audiences in scientific conferences dedicated to Alzheimer's disease and Alzheimer's disease related dementias (AD/ADRD) is not widely supported or studied.

OBJECTIVE

Our objectives were to evaluate the interest, level of engagement, and impact of including general audiences in a virtual dementia conference.

METHODS

A diverse group of lay participants, identified via community-based health advocacy groups and research centers, were invited to attend the 2021 Alzheimer's Association International Conference (AAIC), with optional small-group discussions. Participants received complimentary access to all scientific sessions and were supported via navigation tips, recommended sessions, and a glossary of frequently used terms and acronyms.

RESULTS

Lay participants demonstrated a high level of engagement, even among those that were research-naïve, attending virtual sessions for an average of 11.7 hours across the five days and recommending a variety of sessions to each other on topics extending from prevention of dementia to new therapies and care. Most participants said they would attend the conference again and rated the quality of interaction as high, while requesting more opportunities to engage directly with researchers.

CONCLUSION

General audiences, in particular research participants, are advocating for greater participation in scientific conferences. This program can serve as a model to accomplish inclusion; thereby acknowledging their invaluable contribution to science.

Self-reported fraud victimization and objectively measured blood pressure: Sex differences in post-fraud cardiovascular health

BACKGROUND

Over 5 million older Americans are victims of financial exploitation, schemes, and/or scams per year. Such victimization is associated with increased hospitalizations, admittance to skilled nursing facilities, and lower 5-year all-cause mortality survival rates. Despite this, associations with medical comorbidities like elevated blood pressure (BP) have not been examined.

METHODS

We investigated the association of self-reported fraud victimization (presence/absence) with objectively measured BP metrics leveraging cross-sectional and longitudinal data from over 1200 non-demented adults (75% female; age ~81 years) from the Rush Memory and Aging Project. We first examined cross-sectional associations between baseline fraud victimization and BP, then used longitudinal data to test the hypothesis that fraud victimization is associated with increases in BP after incident fraud. During up to 11 years of annual observation, participants were queried for fraud victimization and underwent serial BP measurements to calculate per visit averages of systolic and diastolic BP, mean arterial pressure (MAP), and pulse pressure.

RESULTS

Cross-sectional analyses established that fraud victimization at baseline was associated with higher BP values. Next, using longitudinal changepoint analyses, we showed that fraud victimization was associated with elevations in BP among men but not women. Specifically, men who reported incident fraud exhibited increases in all BP metrics post-fraud.

CONCLUSION

Results suggest an important link between fraud victimization and BP, particularly among men. Older men showed significant elevations in BP after incident fraud that, compounded over time, may portend other adverse health outcomes.

Amyloid-Related Imaging Abnormalities in the DIAN-TU-001 Trial of Gantenerumab and Solanezumab: Lessons from a Trial in Dominantly Inherited Alzheimer Disease

OBJECTIVE

To determine the characteristics of participants with amyloid-related imaging abnormalities (ARIA) in a trial of gantenerumab or solanezumab in dominantly inherited Alzheimer disease (DIAD).

METHODS

142 DIAD mutation carriers received either gantenerumab SC (n = 52), solanezumab IV (n = 50), or placebo (n = 40). Participants underwent assessments with the Clinical Dementia Rating® (CDR®), neuropsychological testing, CSF biomarkers, β-amyloid positron emission tomography (PET), and magnetic resonance imaging (MRI) to monitor ARIA. Cross-sectional and longitudinal analyses evaluated potential ARIA-related risk factors.

RESULTS

Eleven participants developed ARIA-E, including 3 with mild symptoms. No ARIA-E was reported under solanezumab while gantenerumab was associated with ARIA-E compared to placebo (odds ratio [OR] = 9.1, confidence interval [CI][1.2, 412.3]; p = 0.021). Under gantenerumab, APOE-ɛ4 carriers were more likely to develop ARIA-E (OR = 5.0, CI[1.0, 30.4]; p = 0.055), as were individuals with microhemorrhage at baseline (OR = 13.7, CI[1.2, 163.2]; p = 0.039). No ARIA-E was observed at the initial 225 mg/month gantenerumab dose, and most cases were observed at doses >675 mg. At first ARIA-E occurrence, all ARIA-E participants were amyloid-PET+, 60% were CDR >0, 60% were past their estimated year to symptom onset, and 60% had also incident ARIA-H. Most ARIA-E radiologically resolved after dose adjustment and developing ARIA-E did not significantly increase odds of trial discontinuation. ARIA-E was more frequently observed in the occipital lobe (90%). ARIA-E severity was associated with age at time of ARIA-E.

INTERPRETATION

In DIAD, solanezumab was not associated with ARIA. Gantenerumab dose over 225 mg increased ARIA-E risk, with additional risk for individuals APOE-ɛ4(+) or with microhemorrhage. ARIA-E was reversible on MRI in most cases, generally asymptomatic, without additional risk for trial discontinuation. ANN NEUROL 2022;92:729-744.

Lifestyle and Cognitive Decline in Community-Dwelling Stroke Survivors

Background: Patients with stroke are at a higher risk of cognitive impairment and Alzheimer’s disease dementia. Objective: To quantify the role of lifestyle pre-stroke, post-stroke, and changes in lifestyle before and after stroke with cognitive decline in community-dwelling stroke survivors. Methods: Utilizing data from the Chicago Health and Aging Project, a population-based cohort study, we studied 1,078 individuals with stroke (662 incident and 416 prevalent) who underwent cognitive testing during the study period. A healthy lifestyle score was defined by scoring four behaviors: non-smoking, exercising, being cognitively active, and having a high-quality diet. The global cognitive score was derived from a comprehensive battery of 4 standardized tests. Results: The mean age at incident stroke was 78.2 years, and 60.1% were women. A healthy lifestyle pre-incident stroke was associated with a slower rate of cognitive decline after stroke. Participants with 3–4 healthy lifestyle factors pre-incident stroke had a slower cognitive decline after stroke by 0.046 units/year (95% CI 0.010, 0.083), or 47.7% slower, than participants with 0–1 healthy lifestyle factor. Lifestyle score post-prevalent stroke was not associated with cognitive decline. Changes in lifestyle behaviors from pre- to post-incident stroke were related to cognitive decline after stroke. Individuals who deteriorated their lifestyle quality after stroke had a faster cognitive decline by 0.051 units/year (β –0.051, 95% CI –0.090, –0.012) than participants with no change in lifestyle score. Conclusion: A healthy lifestyle pre-stroke was associated with a slower rate of cognitive decline in stroke survivors, highlighting the importance of primary prevention. After the stroke, changes in lifestyle behaviors may influence the cognitive abilities of older adults as they age.

Cardiology clinic patient attitudes toward and potential personal utility of genetic testing: Findings from a unique multiracial clinical sample

As more is understood about the hereditary nature of disease risk, the utility of genetic testing within cardiovascular medicine is increasingly being explored. Although testing may afford more personalized risk stratification, there is a paucity of information regarding patient knowledge, attitudes, and beliefs toward genetic testing among cardiology patients. Participants (n = 530) recruited primarily from a cardiology clinic filled out a 41-item written questionnaire assessing knowledge, beliefs, and attitudes toward genetic testing, motivators and detractors for considering genetic testing, and perceived likelihood for behavior change after hypothetical genetic testing risk stratification. Path analysis was used to test the hypothetical models predicting the likelihood of getting a genetic test and making behavior changes following genetic testing. The patient population was late-middle-aged (59.0 ± 14.5 years), majority women (61.5%), and about half reported having a bachelor's degree. 58.1% of participants self-identified as White, 25.7% as African American or Black, 6.8% as Spanish, Latino, or Hispanic, 3.0% as Asian or Pacific Islander, and 0.5% as Native American. Gender (being a woman) and more years of education were related to greater knowledge about genetic testing. Racial identity and years of education were related to beliefs about genetic testing. Beliefs, but not knowledge, were related to more positive attitudes and a higher likelihood of pursuing genetic testing. Positive attitudes were related to greater perceived personal control (PPC). Furthermore, attitudes and PPC were related to higher likelihood of lifestyle change after genetic testing. These results highlight the need to integrate the experiences of racialized communities into education/counseling efforts. Most educational counseling efforts lack a nuanced discussion of social determinants of health or beliefs. In addition to factual information, educational counseling must also address people's beliefs, concerns, and the intersecting experiences and identities, which shape patients' relationships with the evolving landscape of healthcare and personalized medicine.

Healthy lifestyle and life expectancy with and without Alzheimer's dementia: population based cohort study

OBJECTIVE

To determine the impact of lifestyle factors on life expectancy lived with and without Alzheimer's dementia.

DESIGN

Prospective cohort study.

SETTING

The Chicago Health and Aging Project, a population based cohort study in the United States.

PARTICIPANTS

2449 men and women aged 65 years and older.

MAIN EXPOSURE

A healthy lifestyle score was developed based on five modifiable lifestyle factors: a diet for brain health (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay-MIND diet score in upper 40% of cohort distribution), late life cognitive activities (composite score in upper 40%), moderate or vigorous physical activity (≥150 min/week), no smoking, and light to moderate alcohol consumption (women 1-15 g/day; men 1-30 g/day).

MAIN OUTCOME

Life expectancy with and without Alzheimer's dementia in women and men.

RESULTS

Women aged 65 with four or five healthy factors had a life expectancy of 24.2 years (95% confidence interval 22.8 to 25.5) and lived 3.1 years longer than women aged 65 with zero or one healthy factor (life expectancy 21.1 years, 19.5 to 22.4). Of the total life expectancy at age 65, women with four or five healthy factors spent 10.8% (2.6 years, 2.0 to 3.3) of their remaining years with Alzheimer's dementia, whereas women with zero or one healthy factor spent 19.3% (4.1 years, 3.2 to 5.1) with the disease. Life expectancy for women aged 65 without Alzheimer's dementia and four or five healthy factors was 21.5 years (20.0 to 22.7), and for those with zero or one healthy factor it was 17.0 years (15.5 to 18.3). Men aged 65 with four or five healthy factors had a total life expectancy of 23.1 years (21.4 to 25.6), which is 5.7 years longer than men aged 65 with zero or one healthy factor (life expectancy 17.4 years, 15.8 to 20.1). Of the total life expectancy at age 65, men with four or five healthy factors spent 6.1% (1.4 years, 0.3 to 2.0) of their remaining years with Alzheimer's dementia, and those with zero or one healthy factor spent 12.0% (2.1 years, 0.2 to 3.0) with the disease. Life expectancy for men aged 65 without Alzheimer's dementia and four or five healthy factors was 21.7 years (19.7 to 24.9), and for those with zero or one healthy factor life expectancy was 15.3 years (13.4 to 19.1).

CONCLUSION

A healthy lifestyle was associated with a longer life expectancy among men and women, and they lived a larger proportion of their remaining years without Alzheimer's dementia. The life expectancy estimates might help health professionals, policy makers, and stakeholders to plan future healthcare services, costs, and needs.

Management of Atrial Fibrillation in Patients 75 Years and Older: JACC State-of-the-Art Review

The prevalence of atrial fibrillation (AF) is increasing as the population ages. AF treatment-related complications also increase markedly in older adults (defined as ≥75 years of age for this review). The older AF population has a high risk of stroke, bleeding, and death. Syncope and fall-related injuries are the most common reasons for nonprescription of oral anticoagulation (OAC), and are more common in older adults when OACs are used with antiarrhythmic drugs. Digoxin may be useful for rate control, but associations with increased mortality limit its use. Beyond rate and rhythm control considerations, stroke prophylaxis is critical to AF management, and the benefits of direct OACs, compared with warfarin, extend to older adults. Invasive procedures such as AF catheter ablation, pacemaker implantation/atrioventricular junction ablation, and left atrial appendage occlusion may be useful in appropriately selected cases. However, older adults have generally been under-represented in clinical trials.

Pelargonidin and Berry Intake Association with Alzheimer's Disease Neuropathology: A Community-Based Study

BACKGROUND

An anthocyanidin, pelargonidin, primarily found in berries, has antioxidant and anti-inflammatory properties, and is associated with better cognition and reduced Alzheimer's dementia risk.

OBJECTIVE

This study investigated if pelargonidin or berry intake is associated with Alzheimer's disease (AD) neuropathology in human brains.

METHODS

The study was conducted among 575 deceased participants (age at death = 91.3±6.1 years; 70% females) of the Rush Memory and Aging Project, with dietary data (assessed using a food frequency questionnaire) and neuropathological evaluations. Calorie-adjusted pelargonidin intake was modeled in quartiles and berry intake as continuous (servings/week). Mean amyloid-beta load and phosphorylated tau neuronal neurofibrillary tangle density across multiple cortical regions were assessed using immunohistochemistry. Global AD pathology burden, a quantitative summary score of neurofibrillary tangles, and diffuse and neuritic plaques using Bielschowsky silver stains in multiple brain regions, was also assessed.

RESULTS

In a linear regression model adjusted for age at death, sex, education, APOE ɛ4 status, vitamin E, and vitamin C, participants in the highest quartile of pelargonidin intake when compared to those in the lowest quartile, had less amyloid-β load (β (SE) = -0.293 (0.14), p = 0.038), and fewer phosphorylated tau tangles (β (SE) = -0.310, p = 0.051). Among APOE ɛ4 non-carriers, higher strawberry (β (SE) = -0.227 (0.11), p = 0.037) and pelargonidin (Q4 versus Q1: β (SE) = -0.401 (0.16), p = 0.011; p trend = 0.010) intake was associated with less phosphorylated tau tangles, no association was observed in APOE ɛ4 carriers. Berry intake was not associated with AD pathology. However, excluding participants with dementia or mild cognitive impairment at baseline, strawberry (p = 0.004) and pelargonidin (ptrend = 0.007) intake were associated with fewer phosphorylated tau tangles.

CONCLUSION

Higher intake of pelargonidin, a bioactive present in strawberries, is associated with less AD neuropathology, primarily phosphorylated tau tangles.

The Advisory Group on Risk Evidence Education for Dementia: Multidisciplinary and Open to All

The brain changes of Alzheimer's disease and other degenerative dementias begin long before cognitive dysfunction develops, and in people with subtle cognitive complaints, clinicians often struggle to predict who will develop dementia. The public increasingly sees benefits to accessing dementia risk evidence (DRE) such as biomarkers, predictive algorithms, and genetic information, particularly as this information moves from research to demonstrated usefulness in guiding diagnosis and clinical management. For example, the knowledge that one has high levels of amyloid in the brain may lead one to seek amyloid reducing medications, plan for disability, or engage in health promoting behaviors to fight cognitive decline. Researchers often hesitate to share DRE data, either because they are insufficiently validated or reliable for use in individuals, or there are concerns about assuring responsible use and ensuring adequate understanding of potential problems when one's biomarker status is known. Concerns include warning people receiving DRE about situations in which they might be compelled to disclose their risk status potentially leading to discrimination or stigma. The Advisory Group on Risk Evidence Education for Dementia (AGREEDementia) welcomes all concerned with how best to share and use DRE. Supporting understanding in clinicians, stakeholders, and people with or at risk for dementia and clearly delineating risks, benefits, and gaps in knowledge is vital. This brief overview describes elements that made this group effective as a model for other health conditions where there is interest in unfettered collaboration to discuss diagnostic uncertainty and the appropriate use and communication of health-related risk information.

Cumulative Concussion and Odds of Stroke in Former National Football League Players

BACKGROUND AND PURPOSE

Postmortem and experimental studies indicate a potential association between repeated concussions and stroke risk in older contact sport athletes. We examined the relationship between concussion and stroke history in former National Football League players aged ≥50 years.

METHODS

Former professional football players aged ≥50 years who played ≥1 year in the National Football League were enrolled in the cross-sectional study. Indirect standardization was used to calculate overall and decade-specific standardized prevalence ratios. Logistic regression using Firth's bias reduction method examined the association between lifetime concussion history 0 (n=119; 12.2%), 1 to 2 (n=152; 15.5%), 3 to 5 (n=242; 24.7%), 6 to 9 (201; 20.5%), and 10+(n=265; 27.1%) and stroke. Adjusted odds ratios for stroke were calculated for concussion history groups, age, and coronary artery disease and/or myocardial infarction.

RESULTS

The 979 participants who met inclusion criteria had a mean age of 65.0±9.0 years (range, 50-99). The prevalence of stroke was 3.4% (n=33), significantly lower than expected based on rates of stroke in US men aged 50 and over (standardized prevalence ratio=0.56, Z= -4.56, P<0.001). Greater odds of stroke history were associated with concussion history (10+ versus 0, adjusted odds ratio [95% CI]=5.51 [1.61-28.95]), cardiovascular disease (adjusted odds ratio [95% CI]=2.24 [1.01-4.77]), and age (1-year-increase adjusted odds ratio [95% CI]=1.07 [1.02-1.11]).

CONCLUSIONS

The prevalence of stroke among former National Football League players aged ≥50 years was lower than the general population, with significantly increased risk among those with 10 or more prior concussions. Findings add to the evidence suggesting that traumatic brain injuries are associated with increased risk of stroke. Clinically, management of cardio- and cerebrovascular health may be pertinent to those with a history of multiple prior concussions.

Leveraging virtual reality to train certified nursing assistants as essential dementia-care personnel in the age of COVID-19

Background

COVID‐19 has placed an extraordinary and disproportionate level of responsibility and risk on certified nursing assistants (CNAs) caring for persons with dementia (PWD) relative to their training, resources, and compensation levels. Nearly one‐quarter of COVID‐19 deaths in the United States have been nursing home residents and staff. Despite providing the majority of direct care, CNAs are amongst the most under‐resourced and under‐trained frontline workers. Given their essentiality, it is critical to support CNAs during the COVID‐19 pandemic. The purpose of this work is to provide CNAs with a space to strengthen their knowledge and confidence in caring for PWD. This pilot study applies a virtual reality (VR) curriculum to train CNAs regarding the lived experiences of PWD and their loved ones. The VR vignette portrays a Latinx woman, Beatriz, through progressive stages of Alzheimer’s disease.

Method

Chicago Methodist Senior Services (CMSS) CNAs were recruited (N=7; 86% female, 86% Black) for a seven‐week online training program consisting of 1.5 hours per week. Each class included a didactic lecture and an Embodied Labs VR module depicting a first‐person experience of dementia through a distributive model approach. The program concluded with two recorded focus groups. Participants completed the UCLA Geriatric Attitudes Scale, a dementia knowledge assessment, the Interpersonal Reactivity Index surveys, and a COVID‐19 Impact questionnaire. Current analyses include qualitative content analysis for focus group data and descriptive, quantitative statistics for pre‐and post‐VR intervention surveys.

Result

Preliminary results demonstrate that CNAs endorsed a positive change in attitudes toward older adults (p=0.069), a deepened understanding of dementia, and increased confidence in caregiving skills. Focus groups allowed CNAs to discuss changes in resident behavior and support one another through a virtual platform during a global pandemic.

Conclusion

Combining traditional didactic lectures with VR‐based curricula provided CNAs with foundational knowledge and first‐hand experience of dementia pathology. Participants reported greater levels of insight and empathy for PWD. Future aims include expansion of training content to include end‐of‐life conversations, LGBTQIA aging, and Lewy body dementia.

Feasibility study for detection of retinal amyloid in clinical trials: The Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) trial

INTRODUCTION

The retina and brain exhibit similar pathologies in patients diagnosed with neurodegenerative diseases. The ability to access the retina through imaging techniques opens the possibility for non-invasive evaluation of Alzheimer's disease (AD) pathology. While retinal amyloid deposits are detected in individuals clinically diagnosed with AD, studies including preclinical individuals are lacking, limiting assessment of the feasibility of retinal imaging as a biomarker for early-stage AD risk detection.

METHODS

In this small cross-sectional study we compare retinal and cerebral amyloid in clinically normal individuals who screened positive for high amyloid levels through positron emission tomography (PET) from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) trial as well as a companion cohort of individuals who exhibited low levels of amyloid PET in the Longitudinal Evaluation of Amyloid Risk and Neurodegeneration (LEARN) study. We quantified the number of curcumin-positive fluorescent retinal spots from a small subset of participants from both studies to determine retinal amyloid deposition at baseline.

RESULTS

The four participants from the A4 trial showed a greater number of retinal spots compared to the four participants from the LEARN study. We observed a positive correlation between retinal spots and brain amyloid, as measured by the standardized uptake value ratio (SUVr).

DISCUSSION

The results of this small pilot study support the use of retinal fundus imaging for detecting amyloid deposition that is correlated with brain amyloid PET SUVr. A larger sample size will be necessary to fully ascertain the relationship between amyloid PET and retinal amyloid both cross-sectionally and longitudinally.

Higher circulating α-carotene was associated with better cognitive function: an evaluation among the MIND trial participants

There is emerging evidence linking fruit and vegetable consumption and cognitive function. However, studies focusing on the nutrients underlying this relationship are lacking. We aim to examine the association between plasma nutrients and cognition in a population at risk for cognitive decline with a suboptimal diet. The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) trial is a randomized controlled intervention that examines the effects of the MIND diet to prevent cognitive decline. The primary outcome is global cognition. A multivariate linear model was used to investigate the association between blood nutrients and global and/or domain-specific cognition. The model was adjusted for age, sex, education, study site, smoking status, cognitive activities and physical activities. High plasma α-carotene was associated with better global cognition. Participants in the highest tertile of plasma α-carotene had a higher global cognition z score of 0⋅17 when compared with individuals in the lowest tertile (P 0⋅002). Circulating α-carotene levels were also associated with higher semantic memory scores (P for trend 0⋅007). Lutein and zeaxanthin (combined) was positively associated with higher semantic memory scores (P for trend 0⋅009). Our study demonstrated that higher α-carotene levels in blood were associated with higher global cognition scores in a US population at risk for cognitive decline. The higher α-carotene levels in blood reflected greater intakes of fruits, other types of vegetables and lesser intakes of butter and margarine and meat. The higher circulating levels of lutein plus zeaxanthin reflected a dietary pattern with high intakes of fruits, green leafy, other vegetables and cheese, and low consumption of fried foods. Objective nutrient markers in the blood can better characterize dietary intake, which may facilitate the implementation of a tailored dietary intervention for the prevention of cognitive decline.

Longitudinal Association of Total Tau Concentrations and Physical Activity With Cognitive Decline in a Population Sample

IMPORTANCE

Tau is a brain protein located in neurons and develops abnormally in individuals with Alzheimer disease. New technology is convenient for measuring blood total tau concentrations and provides a unique and increased opportunity for early intervention to slow cognitive decline.

OBJECTIVE

To evaluate the association of physical activity and total tau concentrations with cognitive decline at baseline and over time.

DESIGN, SETTING, AND PARTICIPANTS

The Chicago Health and Aging Project is a population-based cohort study conducted in 4 Chicago communities. Data collection occurred in 3-year cycles between 1993 and 2012. Participants completed in-home interviews. Clinical evaluations, which included blood samples, were performed with a stratified random sample of 1159 participants. Statistical analyses were conducted from October 30, 2020, to May 25, 2021.

EXPOSURES

Physical activity and total serum tau concentrations. Data on physical activity were obtained through self-report items, and a sum of minutes per week was calculated. Little physical activity was defined as no participation in a minimum of 4 of the items on the physical activity measure. Medium activity was defined as participating in less than 150 minutes of physical activity per week, and high activity was defined as participating in 150 minutes or more of physical activity per week.

MAIN OUTCOMES AND MEASURES

The main outcome for this study is global cognitive function, measured through a battery of cognitive tests. The study hypothesis was developed after data were collected.

RESULTS

Of the 1159 participants in the study, 728 were women (63%), and 696 were African American (60%); the mean (SD) age was 77.4 (6.0) years, and the mean (SD) educational level was 12.6 (3.5) years. Participants with high total tau concentrations with medium physical activity had a 58% slower rate of cognitive decline (estimate, -0.028 standard deviation unit [SDU] per year [95% CI, -0.057 to 0.002 SDU per year]; difference, 0.038 SDU per year [95% CI, 0.011-0.065 SDU per year]), and those with high physical activity had a 41% slower rate of cognitive decline (estimate, -0.038 SDU per year [95% CI, -0.068 to -0.009 SDU per year]; difference, 0.027 SDU per year [95% CI, -0.002 to 0.056 SDU per year]), compared with those with little physical activity. Among participants with low total tau concentrations, medium physical activity was associated with a 2% slower rate of cognitive decline (estimate, -0.050 SDU per year [95% CI, -0.069 to -0.031 SDU per year]; difference, 0.001 SDU per year [95% CI, -0.019 to 0.021 SDU per year]), and high physical activity was associated with a 27% slower rate of cognitive decline (estimate, -0.037 SDU per year [95% CI, -0.055 to -0.019 SDU per year]; difference, 0.014 SDU per year [95% CI, -0.007 to 0.034 SDU per year]), compared with little physical activity. Individual tests of cognitive function showed similar results.

CONCLUSIONS AND RELEVANCE

This study suggests that, among participants with both high and low total tau concentrations, physical activity was associated with slower cognitive decline. Results support the potential utility of blood biomarkers in measuring the benefits associated with health behaviors and may contribute to specifying target populations or informing interventions for trials that focus on improving physical activity behavior. Future work should examine the association of total tau concentrations with other health behaviors and physical activity types.

MIND Diet, Common Brain Pathologies, and Cognition in Community-Dwelling Older Adults

BACKGROUND

MIND diet, a hybrid of the Mediterranean diet and the Dietary Approaches to Stop Hypertension diet, is associated with a slower cognitive decline and lower risk of Alzheimer's disease (AD) dementia in older adults.

OBJECTIVE

We aim to examine whether the association of the MIND diet with cognition is independent of common brain pathologies.

METHODS

Utilizing data from the Rush Memory and Aging Project (MAP), a longitudinal clinical-pathologic study, we studied 569 decedents with valid dietary data, cognitive testing proximate to death, and complete autopsy data at the time of these analyses. A series of regression analyses were used to examine associations of the MIND diet, dementia-related brain pathologies, and global cognition proximate to death adjusting for age, sex, education, APOEɛ4, late-life cognitive activities, and total energy intake.

RESULTS

A higher MIND diet score was associated with better global cognitive functioning proximate to death (β= 0.119, SE = 0.040, p = 0.003), and neither the strength nor the significance of association changed substantially when AD pathology and other brain pathologies were included in the model. The β-estimate after controlling for global AD pathology was 0.111 (SE = 0.037, p = 0.003). The MIND diet-cognition relationship remained significant when we restricted our analysis to individuals without mild cognitive impairment at the baseline (β= 0.121, SE = 0.042, p = 0.005) or in people diagnosed with postmortem diagnosis of AD based on NIA-Reagan consensus recommendations (β= 0.114, SE = 0.050, p = 0.023).

CONCLUSION

MIND diet is associated with better cognitive functioning independently of common brain pathology, suggesting that the MIND diet may contribute to cognitive resilience in the elderly.

Genetic risk, adherence to a healthy lifestyle, and cognitive decline in African Americans and European Americans

INTRODUCTION

We investigated the role of genetic risk and adherence to lifestyle factors on cognitive decline in African Americans and European Americans.

METHODS

Using data from the Chicago Health and Aging Project (1993-2012; n = 3874), we defined the genetic risk based on presence of apolipoprotein E (APOE) ε 4 allele and determined a healthy lifestyle using a scoring of five factors: non-smoking, exercising, being cognitively active, having a high-quality diet, and limiting alcohol use. We used linear mixed-effects models to estimate cognitive decline by genetic risk and lifestyle score.

RESULTS

APOE  ε 4 allele was associated with faster cognitive decline in both races. However, within APOE  ε 4 carriers, adherence to a healthy lifestyle (eg., 4 to 5 healthy factors) was associated with a slower cognitive decline by 0.023 (95% confidence interval [CI] 0.004, 0.042) units/year in African Americans and 0.044 (95% CI 0.008, 0.080) units/year in European Americans.

DISCUSSION

A healthy lifestyle was associated with a slower cognitive decline in African and European Americans.

Disparities by Race and Ethnicity Among Adults Recruited for a Preclinical Alzheimer Disease Trial

IMPORTANCE

Underrepresentation of many racial/ethnic groups in Alzheimer disease (AD) clinical trials limits generalizability of results and hinders opportunities to examine potential effect modification of candidate treatments.

OBJECTIVE

To examine racial and ethnic differences in recruitment methods and trial eligibility in a multisite preclinical AD trial.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study analyzed screening data from the Anti-Amyloid in Asymptomatic AD study, collected from April 2014 to December 2017. Participants were categorized into 5 mutually exclusive ethnic/racial groups (ie, Hispanic, Black, White, Asian, and other) using participant self-report. Data were analyzed from May through December 2020 and included 5945 cognitively unimpaired older adults between the ages of 65 and 85 years screened at North American study sites.

MAIN OUTCOMES AND MEASURES

Primary outcomes included recruitment sources, study eligibility, and ineligibility reasons. To assess the probability of trial eligibility, regression analyses were performed for the likelihood of being eligible after the first screening visit involving clinical and cognitive assessments.

RESULTS

Screening data were included for 5945 participants at North American sites (mean [SD] age, 71.7 [4.9] years; 3524 women [59.3%]; 5107 White [85.9%], 323 Black [5.4%], 261 Hispanic [4.4%], 112 Asian [1.9%], and 142 [2.4%] who reported race or ethnicity as other). Recruitment sources differed by race and ethnicity. While White participants were recruited through a variety of sources, site local recruitment efforts resulted in the majority of Black (218 [69.2%]), Hispanic (154 [59.7%]), and Asian (61 [55.5%]) participants. Participants from underrepresented groups had lower mean years of education (eg, mean [SD] years: Hispanic participants, 15.5 [3.2] years vs White participants, 16.7 [2.8] years) and more frequently were women (226 [70.0%] Black participants vs 1364 [58.5%] White participants), were unmarried (184 [56.9%] Black participants vs 1364 [26.7%] White participants), and had nonspousal study partners (237 [73.4%] Black participants vs 2147 [42.0%] White participants). They were more frequently excluded for failure to meet cognitive inclusion criteria (eg, screen failures by specific inclusion criteria: 147 [45.5%] Black participants vs 1338 [26.2%] White participants). Compared with White participants, Black (odds ratio [OR], 0.43; 95% CI, 0.34-0.54; P < .001), Hispanic (OR, 0.53; 95% CI, 0.41-0.69; P < .001), and Asian participants (OR, 0.56; 95% CI, 0.38-0.82; P = .003) were less likely to be eligible after screening visit 1.

CONCLUSIONS AND RELEVANCE

Racial/ethnic groups differed in sources of recruitment, reasons for screen failure, and overall probability of eligibility in a preclinical AD trial. These results highlight the need for improved recruitment strategies and careful consideration of eligibility criteria when planning preclinical AD clinical trials.

Impact of the Apolipoprotein E ε4 Allele on the Relationship Between Healthy Lifestyle and Cognitive Decline: A Population-Based Study

Adherence to a healthy lifestyle-characterized by abstaining from smoking, being physically and cognitively active, having a high-quality diet, and limiting alcohol use-is associated with slower cognitive decline in older adults, but whether this relationship extends to persons with a genetic predisposition (e.g., carriers of the ε4 allele of the apolipoprotein E gene (APOE*E4)) remains uncertain. Using data from a population-based study, the Chicago Health and Aging Project (Chicago, Illinois), we followed 3,886 individuals who underwent regular clinical and cognitive assessments from 1993 to 2012. Of 3,886 older adults, 1,269 (32.7%) were APOE*E4 carriers. Compared with noncarriers, APOE*E4 carriers had faster cognitive decline (β = -0.027 units/year, 95% confidence interval (CI): -0.032, -0.023). In contrast, persons with 2-3 and 4-5 healthy lifestyle factors had slower cognitive decline (β = 0.008 units/year (95% CI: 0.002, 0.014) and β = 0.019 units/year (95% CI: 0.011, 0.026), respectively) compared with those with 0-1 factor. In analyses stratified by APOE*E4 status, adherence to a healthy lifestyle (e.g., 4-5 factors vs. 0-1 factors) was associated with a slower rate of cognitive decline in both APOE*E4 carriers (β = 0.029, 95% CI: 0.013, 0.045) and noncarriers (β = 0.013, 95% CI: 0.005, 0.022). These results underscore the impact of a healthy lifestyle on cognition, particularly among persons with a genetic predisposition, who are more vulnerable to cognitive decline as they age.

Vitamin D Intake and Brain Cortical Thickness in Community-Dwelling Overweight Older Adults: A Cross-Sectional Study

BACKGROUND

Vitamin D is critical to brain health and a promising candidate to prevent cognitive decline and onset of Alzheimer disease (AD), although the underlying brain mechanisms are unclear.

OBJECTIVES

This study aimed to determine the association between vitamin D intake and brain cortical thickness in older adults.

METHODS

This was a cross-sectional investigation of 263 cognitively unimpaired participants, aged 65 y and older, participating in the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) trial (an ongoing study testing the effects of a 3-y diet intervention on cognitive decline). Vitamin D intake, from diet and supplements, was ascertained from an FFQ. Linear regression analysis, adjusted for age, sex, race, education, income, cognitive and physical activities, and cardiovascular disease risk factors, was used to determine the association between vitamin D intake and cortical thickness of the whole brain, lobes, and AD signature.

RESULTS

Total vitamin D intake was associated with cortical thickness of the temporal lobe and AD signature. Compared with individuals in the lowest quartile of total vitamin D intake [median: 140 international units (IU)/d], those in the highest quartile (median: 1439 IU/d) had a 0.038-mm (95% CI: 0.006, 0.069 mm) thicker temporal lobe and 0.041-mm (95% CI: 0.012, 0.070 mm) thicker AD signature. Most vitamin D intake was from supplements, and supplemental intake was also associated with cortical thickness. Compared with those who used no supplement, individuals taking 800-1000 IU/d and >1000 IU/d of supplemental vitamin D had a 0.039-mm (95% CI: 0.013, 0.066 mm) and 0.047-mm (95% CI: 0.013, 0.081 mm) thicker temporal lobe and a 0.037-mm (95% CI: 0.013, 0.061 mm) and 0.046-mm (95% CI: 0.015, 0.077 mm) thicker AD signature, respectively. Dietary vitamin D was not related to brain cortical thickness in our sample.

CONCLUSIONS

In cognitively unimpaired older adults, total and supplemental vitamin D intakes were associated with cortical thickness in regions vulnerable to AD.This trial was registered at clinicaltrials.gov as NCT02817074.