H - 07 Associations among Cardiovascular Factors, Mood, and Cognition in Older Latinos: Preliminary Results from the Boston Latino Aging Study

OBJECTIVE

Cardiovascular risk factors and depression are prevalent in Latino populations and have been associated with an increased risk of cognitive decline and dementia. Adults with depressive symptoms also have an increased risk of cardiovascular disease. Understanding the link between these factors and how they impact dementia risk among Latino cohorts is critical for the development of preventative interventions. We examined the associations among cardiovascular risk factors, depression, and cognitive status in older Latinos living in Massachusetts.

METHOD

A total of 42 participants enrolled in the Boston Latino Aging Study (BLAST; n = 28, mean age = 65.36, SD = 7.35) and the Harvard Aging Brain Study Latino cohort (LHABS) (n = 14, mean age = 71.43, SD = 6.89) were included in the analyses. Participants completed a screening evaluation that included the Telephone Interview Cognitive Screen (TICS), the Geriatric Depression Scale (GDS), blood sampling to assess cholesterol, fasting glucose, and triglyceride levels, and systolic/diastolic blood pressure measurements. Spearman correlations were used to determine associations among cardiovascular risk factors, depression (GDS), and cognitive status (TICS).

RESULTS

We found that triglycerides (r = -0.424, p = 0.005) and glucose (r = -0.317, p = 0.041) were negatively correlated with TICS. Systolic blood pressure (r = 0.325, p = 0.036) and fasting glucose (r = 0.327, p = 0.034) were positively correlated with GDS scores.

CONCLUSION(S)

Preliminary results suggest a link between cardiovascular risk factors (e.g., elevated triglycerides and glucose) and worse cognitive status. Additionally, findings suggest cardiovascular risk factors may be related to depressive symptoms in older Latinos. Further work with larger samples of Latino participants is needed to confirm our findings and examine relevant associations with other risk factors.

A - 30 Risk Factors for Poor Sleep Quality and Subjective Cognitive Decline during the COVID-19 Pandemic in an Ethnoracially Diverse US Sample

OBJECTIVE

Poor sleep quality is associated with subjective cognitive decline (SCD), a risk factor for developing Alzheimer's disease and Mild Cognitive Impairment. These relationships are understudied in ethnoracially diverse groups. We examined associations between sociodemographic characteristics, sleep changes during the COVID-19 pandemic (i.e., increased problems/poorer quality), and SCD in ethnoracially diverse older individuals in the US.

METHOD

870 older adults (126 Latino, 74 Black, 33 Asian, and 637 White; Mage = 67.0 [7.6]) completed an online survey including sociodemographic information, the Everyday Cognition scale (ECog), which measures SCD, and a question inquiring about increased sleep problems/worsened sleep quality during the pandemic. Chi-square tests and analyses of variance assessed sociodemographic and SCD differences between groups. Regression and correlation analyses assessed relationships among sociodemographic factors, changes in sleep quality, and SCD.

RESULTS

White participants were older (p < 0.001), and White and Asian groups had higher education levels (p = 0.009) than Latinos. There were more female (p = 0.016) and middle-income (p = 0.019) White respondents. There were no group differences in ECog ratings (p = 0.143) or the proportion of respondents endorsing changes in sleep during the pandemic (p = 0.197). Changes in sleep were associated with greater SCD (β = 0.214, p < 0.001). Younger age (p < 0.001), female sex (p = 0.001), and lower income (p = 0.016) were significant predictors of changes in sleep.

CONCLUSIONS

Poorer sleep quality resulting from the COVID-19 pandemic was associated with SCD concerns. Notably, younger, female, and lower-income adults may have been at greater risk for increased sleep problems. Future work is needed to comprehensively examine sleep quality, SCD, and objective cognitive functioning in more representative samples.

Sex differences in blood biomarkers and cognitive performance in individuals with autosomal dominant Alzheimer's disease

INTRODUCTION

Plasma tau phosphorylated at threonine 217 (P-tau217) and neurofilament light (NfL) have emerged as markers of Alzheimer's disease (AD) pathology. Few studies have examined the role of sex in plasma biomarkers in sporadic AD, yielding mixed findings, and none in autosomal dominant AD.

METHODS

We examined the effects of sex and age on plasma P-tau217 and NfL, and their association with cognitive performance in a cross-sectional study of 621 Presenilin-1 E280A mutation carriers (PSEN1) and non-carriers.

RESULTS

As plasma P-tau217 levels increase, cognitively unimpaired female carriers showed better cognitive performance than cognitively unimpaired male carriers. Yet, as disease progresses, female carriers had a greater plasma NfL increase than male carriers. There were no sex differences in the association between age and plasma biomarkers among non-carriers.

DISCUSSION

Our findings suggest that, among PSEN1 mutation carriers, females had a greater rate of neurodegeneration than males, yet it did not predict cognitive performance.

HIGHLIGHTS

We examined sex differences in plasma P-tau217 and NfL in Presenilin-1 E280A (PSEN1) mutation carriers and non-carriers. Female carriers had a greater plasma NfL increase, but not P-tau217, than male carriers. As plasma P-tau217 levels increase, cognitively unimpaired female carriers showed better cognitive performance than cognitively unimpaired male carriers. The interaction effect of sex by plasma NfL levels did not predict cognition among carriers.

Associations Among Loneliness, Purpose in Life and Subjective Cognitive Decline in Ethnoracially Diverse Older Adults Living in the United States

Subjective cognitive decline (SCD), which precedes Mild Cognitive Impairment and dementia, may be affected by purpose in life (PiL) and loneliness in older adults. We investigated associations among PiL, loneliness, and SCD in US Latino (n = 126), Black (n = 74), Asian (n = 33), and White (n = 637) adults. Higher PiL predicted lower SCD in all groups (p-values < .012), except Black participants. Lower loneliness predicted lower SCD in Latino and White groups (p-values < .05), and PiL moderated this association in White adults. PiL and loneliness may play important roles in cognitive decline. Differential predictors of SCD suggest differential targets for preventing cognitive decline and dementia across ethnoracial groups.

Waning locus coeruleus integrity precedes cortical tau accrual in preclinical autosomal dominant Alzheimer's disease

INTRODUCTION

Autopsy studies recognize the locus coeruleus (LC) as one of the first sites accumulating tau in Alzheimer's disease (AD). Recent AD work related in vivo LC magnetic resonance imaging (MRI) integrity to tau and cognitive decline; however, relationships of LC integrity to age, tau, and cognition in autosomal dominant AD (ADAD) remain unexplored.

METHODS

We associated LC integrity (3T-MRI) with estimated years of onset, cortical amyloid beta, regional tau (positron emission tomography [PET]) and memory (Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word-List-Learning) among 27 carriers and 27 non-carriers of the presenilin-1 (PSEN1) E280A mutation. Longitudinal changes between LC integrity and tau were evaluated in 10 carriers.

RESULTS

LC integrity started to decline at age 32 in carriers, 12 years before clinical onset, and 20 years earlier than in sporadic AD. LC integrity was negatively associated with cortical tau, independent of amyloid beta, and predicted precuneus tau increases. LC integrity was positively associated with memory.

DISCUSSION

These findings support LC integrity as marker of disease progression in preclinical ADAD.

Virtual mentalizing imagery therapy for Spanish language Latino family dementia caregivers: A feasibility and acceptability study

Spanish speaking family caregivers of people living with dementia have limited supportive resources in Spanish. There are few validated, culturally acceptable virtual interventions for reducing these caregivers' psychological distress. We investigated the feasibility of a Spanish language adaptation of a virtual Mentalizing Imagery Therapy (MIT) program, which provides guided imagery and mindfulness training to reduce depression, increase mentalizing, and promote well-being. 12 Spanish-speaking family dementia caregivers received a 4-week virtual MIT program. Follow-up was obtained post group and at 4 months post baseline assessment. Feasibility, acceptability, and satisfaction with MIT were assessed. The primary psychological outcome was depressive symptoms; secondary outcomes included caregiver burden, dispositional mindfulness, perceived stress, well-being, interpersonal support, and neurological quality of life. Statistical analysis was performed with mixed linear models. Caregivers were 52 ± 8 (mean ± SD) years of age. 60% had a high school education or less. Participation in weekly group meetings was 100%. Home practice was performed on average 4 ± 1 times per week [range 2-5]. Satisfaction with MIT reached 19 ± 2 of a possible 20 points. Reduction in depression from baseline was observed by week three (p = 0.01) and maintained at 4 month follow-up (p = 0.05). There were significant improvements in mindfulness post-group, and in caregiver burden and well-being at 4 months. MIT was successfully adapted for Latino Spanish language family dementia caregivers within a virtual group environment. MIT is feasible and acceptable and may help reduce depressive symptoms and improve subjective well-being. Larger, randomized controlled trials of MIT should determine durability of effects and validate efficacy in this population.

Distinct tau neuropathology and cellular profiles of an APOE3 Christchurch homozygote protected against autosomal dominant Alzheimer's dementia

We describe in vivo follow-up PET imaging and postmortem findings from an autosomal dominant Alzheimer's disease (ADAD) PSEN1 E280A carrier who was also homozygous for the APOE3 Christchurch (APOE3ch) variant and was protected against Alzheimer's symptoms for almost three decades beyond the expected age of onset. We identified a distinct anatomical pattern of tau pathology with atypical accumulation in vivo and unusual postmortem regional distribution characterized by sparing in the frontal cortex and severe pathology in the occipital cortex. The frontal cortex and the hippocampus, less affected than the occipital cortex by tau pathology, contained Related Orphan Receptor B (RORB) positive neurons, homeostatic astrocytes and higher APOE expression. The occipital cortex, the only cortical region showing cerebral amyloid angiopathy (CAA), exhibited a distinctive chronic inflammatory microglial profile and lower APOE expression. Thus, the Christchurch variant may impact the distribution of tau pathology, modulate age at onset, severity, progression, and clinical presentation of ADAD, suggesting possible therapeutic strategies.

The impact of COVID-19 on the well-being and cognition of older adults living in the United States and Latin America

BACKGROUND

In the COVID-19 pandemic, older adults from vulnerable ethnoracial groups are at high risk of infection, hospitalization, and death. We aimed to explore the pandemic's impact on the well-being and cognition of older adults living in the United States (US), Argentina, Chile, Mexico, and Peru.

METHODS

1,608 (646 White, 852 Latino, 77 Black, 33 Asian; 72% female) individuals from the US and four Latin American countries aged ≥ 55 years completed an online survey regarding well-being and cognition during the pandemic between May and September 2020. Outcome variables (pandemic impact, discrimination, loneliness, purpose of life, subjective cognitive concerns) were compared across four US ethnoracial groups and older adults living in Argentina, Chile, Mexico, and Peru.

FINDINGS

Mean age for all participants was 66.7 (SD = 7.7) years and mean education was 15.4 (SD = 2.7) years. Compared to Whites, Latinos living in the US reported greater economic impact (p < .001, ηp 2  = 0.031); while Blacks reported experiencing discrimination more often (p < .001, ηp 2  = 0.050). Blacks and Latinos reported more positive coping (p < .001, ηp 2  = 0.040). Compared to Latinos living in the US, Latinos in Chile, Mexico, and Peru reported greater pandemic impact, Latinos in Mexico and Peru reported more positive coping, Latinos in Argentina, Mexico, and Peru had greater economic impact, and Latinos in Argentina, Chile, and Peru reported less discrimination.

INTERPRETATION

The COVID-19 pandemic has differentially impacted the well-being of older ethnically diverse individuals in the US and Latin America. Future studies should examine how mediators like income and coping skills modify the pandemic's impact.

FUNDING

Massachusetts General Hospital Department of Psychiatry.

Longitudinal amyloid and tau accumulation in autosomal dominant Alzheimer's disease: findings from the Colombia-Boston (COLBOS) biomarker study

BACKGROUND

Neuroimaging studies of autosomal dominant Alzheimer's disease (ADAD) enable characterization of the trajectories of cerebral amyloid-β (Aβ) and tau accumulation in the decades prior to clinical symptom onset. Longitudinal rates of regional tau accumulation measured with positron emission tomography (PET) and their relationship with other biomarker and cognitive changes remain to be fully characterized in ADAD.

METHODS

Fourteen ADAD mutation carriers (Presenilin-1 E280A) and 15 age-matched non-carriers from the Colombian kindred underwent 2-3 sessions of Aβ (11C-Pittsburgh compound B) and tau (18F-flortaucipir) PET, structural magnetic resonance imaging, and neuropsychological evaluation over a 2-4-year follow-up period. Annualized rates of change for imaging and cognitive variables were compared between carriers and non-carriers, and relationships among baseline measurements and rates of change were assessed within carriers.

RESULTS

Longitudinal measurements were consistent with a sequence of ADAD-related changes beginning with Aβ accumulation (16 years prior to expected symptom onset, EYO), followed by entorhinal cortex (EC) tau (9 EYO), neocortical tau (6 EYO), hippocampal atrophy (6 EYO), and cognitive decline (4 EYO). Rates of tau accumulation among carriers were most rapid in parietal neocortex (~ 9%/year). EC tau PET signal at baseline was a significant predictor of subsequent neocortical tau accumulation and cognitive decline within carriers.

CONCLUSIONS

Our results are consistent with the sequence of biological changes in ADAD implied by cross-sectional studies and highlight the importance of EC tau as an early biomarker and a potential link between Aβ burden and neocortical tau accumulation in ADAD.

Neuropsychological Profiles Differentiate Alzheimer Disease from Subcortical Ischemic Vascular Dementia in an Autopsy-Defined Cohort

BACKGROUND/AIMS

The aim of this study was to assess the ability of neuropsychological tests to differentiate autopsy-defined Alzheimer disease (AD) from subcortical ischemic vascular dementia (SIVD).

METHODS

From a sample of 175 cases followed longitudinally that underwent autopsy, we selected 23 normal controls (NC), 20 SIVD, 69 AD, and 10 mixed cases of dementia. Baseline neuropsychological tests, including Memory Assessment Scale word list learning test, control oral word association test, and animal fluency, were compared between the three autopsy-defined groups.

RESULTS

The NC, SIVD, and AD groups did not differ by age or education. The SIVD and AD groups did not differ by the Global Clinical Dementia Rating Scale. Subjects with AD performed worse on delayed recall (p < 0.01). A receiver operating characteristics analysis comparing the SIVD and AD groups including age, education, difference between categorical (animals) versus phonemic fluency (letter F), and the first recall from the word learning test distinguished the two groups with a sensitivity of 85%, specificity of 67%, and positive likelihood ratio of 2.57 (AUC = 0.789, 95% CI 0.69-0.88, p < 0.0001).

CONCLUSION

In neuropathologically defined subgroups, neuropsychological profiles have modest ability to distinguish patients with AD from those with SIVD.

Clinical and imaging features of mixed Alzheimer and vascular pathologies

The co-occurrence of both Alzheimer disease (AD) pathology and vascular brain injury (VBI) is very common, especially amongst the oldest of old. In neuropathologic studies, the prevalence of AD, VBI, and mixed AD/VBI lesions ranks ahead of Lewy bodies and hippocampal sclerosis. In the modern era of structural magnetic resonance imaging (MRI) and amyloid positron emission tomography (PET) imaging, this review examines 1) the prevalence of mixed AD and VBI pathology, 2) the significance of these pathologies for cognitive impairment (AD and vascular cognitive impairment (VCI)), and 3) the diagnosis and treatment of mixed AD/VCI. Although epidemiologic studies report that vascular risk factors for arteriosclerosis increase the risk of incident AD, both autopsy and amyloid PET studies indicate that AD and VBI contribute additively, but independently, to the risk of dementia. The literature confirms the malignancy of AD and highlights the adverse effects of microinfarcts on cognitive function. For the clinical diagnosis of mixed AD/VCI, the presence of AD can be recognized by neuropsychological profile, structural imaging, cerebrospinal fluid biomarkers, and glucose PET and amyloid PET imaging. The diagnosis of VBI, however, still hinges predominantly on the structural MRI findings. Severe amnesia and atrophy of the hippocampus are characteristic of early AD, whereas the cognitive profile for VCI is highly variable and dependent on size and location of VBI. The cognitive profile of mixed AD/VBI is dominated by AD. With the notable exception of microinfarcts (which elude in vivo detection), infarcts, hemorrhages, and white matter hyperintensities on structural MRI currently represent the best markers for the presence VBI. Better markers that reflect the health and reactivity of intracerebral blood vessels are needed. For prevention and treatment, the type of underlying cerebrovascular disease (for example, arteriosclerosis or cerebral amyloid angiopathy) should be considered. It is likely that reduction of vascular risk factors for arteriosclerosis can significantly reduce vascular contributions to mixed dementia.