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BackgroundAlthough not strongly correlated with current objective cognitive ability, subjective cognitive decline (SCD) is a risk factor for Alzheimer's disease. Most studies focus on SCD in relation to future decline rather than objective prior decline that it purportedly measures.ObjectiveWe evaluated whether self-report of cognitive decline-as a continuous measure-corresponds to objectively-assessed episodic memory and executive function decline across the same period.Methods1,170 men completed the Everyday Cognition Questionnaire (ECog) at mean age 68 assessing subjective changes in cognitive ability relative to 10 years prior. A subset had mild cognitive impairment (MCI), but MCI was diagnosed without regard to subjective decline. Participants completed up to 3 objective assessments of memory and executive function (M = 56, 62, and 68 years). Informant-reported ECogs were completed for 1,045 individuals. Analyses controlled for depression and anxiety symptoms assessed at mean age 68.ResultsParticipant-reported ECog scores were modestly associated with objective decline for memory (β= -0.23, 95%CI [-0.37, -0.10]) and executive function (β= -0.19, 95%CI [-0.33, -0.05]) over the same time period. However, these associations were nonsignificant after excluding MCI cases. Results were similar for informant ratings. Participant-rated ECog scores were more strongly associated with concurrent depression and anxiety symptoms, (β= 0.44, 95%CI [0.36, 0.53]).ConclusionContinuous SCD scores are correlated with prior objective cognitive changes in non-demented individuals, though this association appears driven by individuals with current MCI. However, participants' current depression and anxiety ratings tend to be strongly associated with their SCD ratings. Thus, what primarily drives SCD ratings remains unclear.

Approximately 30% of older adults exhibit the neuropathological features of Alzheimer's disease without signs of cognitive impairment. Yet, little is known about the genetic factors that allow these potentially resilient individuals to remain cognitively unimpaired in the face of substantial neuropathology. We performed a large, genome-wide association study (GWAS) of two previously validated metrics of cognitive resilience quantified using a latent variable modelling approach and representing better-than-predicted cognitive performance for a given level of neuropathology. Data were harmonized across 5108 participants from a clinical trial of Alzheimer's disease and three longitudinal cohort studies of cognitive ageing. All analyses were run across all participants and repeated restricting the sample to individuals with unimpaired cognition to identify variants at the earliest stages of disease. As expected, all resilience metrics were genetically correlated with cognitive performance and education attainment traits (P-values < 2.5 × 10-20), and we observed novel correlations with neuropsychiatric conditions (P-values < 7.9 × 10-4). Notably, neither resilience metric was genetically correlated with clinical Alzheimer's disease (P-values > 0.42) nor associated with APOE (P-values > 0.13). In single variant analyses, we observed a genome-wide significant locus among participants with unimpaired cognition on chromosome 18 upstream of ATP8B1 (index single nucleotide polymorphism rs2571244, minor allele frequency = 0.08, P = 2.3 × 10-8). The top variant at this locus (rs2571244) was significantly associated with methylation in prefrontal cortex tissue at multiple CpG sites, including one just upstream of ATPB81 (cg19596477; P = 2 × 10-13). Overall, this comprehensive genetic analysis of resilience implicates a putative role of vascular risk, metabolism, and mental health in protection from the cognitive consequences of neuropathology, while also providing evidence for a novel resilience gene along the bile acid metabolism pathway. Furthermore, the genetic architecture of resilience appears to be distinct from that of clinical Alzheimer's disease, suggesting that a shift in focus to molecular contributors to resilience may identify novel pathways for therapeutic targets.

Background: "SuperAgers" are older adults (ages 80+) whose cognitive performance resembles that of adults in their 50s to mid‐60s. Factors underlying their exemplary aging are underexplored in large, racially diverse cohorts. Using eight cohorts, we investigated the frequency of APOE genotypes in SuperAgers compared to middle‐aged and older adults. Method: Harmonized, longitudinal memory, executive function, and language scores in Non‐Hispanic White (NHW) and Non‐Hispanic Black (NHB) participants were obtained from the ADSP Phenotype Harmonization Consortium. Scores were age‐ and sex‐adjusted. SuperAgers (NHW = 1,625; NHB = 106) included individuals 80+ years of age with a memory score equal to or exceeding individuals aged 50‐64 and language and executive function domain scores within normal limits who remain cognitively normal across visits. SuperAgers were compared to Alzheimer's disease (AD) cases (NHW = 8,400; NHB = 925) and cognitively normal controls (NHW = 7,355; NHB = 1,305), as well as age‐defined subgroups (Young = ages 50‐64, Older = ages 65‐79, Oldest‐Old = age 80+). We performed binary logistic regression analyses comparing APOE‐ε2 and APOE‐ε4 alleles (0 = none, 1 = 1+ alleles present) among SuperAgers and their counterparts, covarying for sex and education. We corrected for multiple comparisons using the Benjamini‐Hochberg procedure. Results: Across racial groups, SuperAgers had significantly higher proportions with APOE‐ε2 alleles and lower proportions with APOE‐ε4 alleles compared to cases (Table 1, Figure 1). Similar differences were observed between SuperAgers and Young and Old Controls, although differences were restricted to APOE‐ε4 in NHB comparisons. NHW SuperAgers had lower proportions with APOE‐ε4 alleles compared to Oldest‐Old Controls; APOE‐ε2 proportions did not differ. Conclusion: Within our large, harmonized cohort, larger proportions of SuperAgers had APOE‐ε2 alleles and smaller proportions had APOE‐ε4 alleles than AD cases across both NHW and NHB participants. Crucially, higher proportions of NHW SuperAgers had APOE‐ε2 alleles than younger controls (ages<80) and lower proportions had APOE‐ε4 alleles than all controls including age‐matched controls (ages 80+). This work provides the strongest evidence to date that APOE is associated with SuperAging. APOE‐ε2 did not differentiate NHB SuperAgers from controls nor APOE‐ε4 from other oldest‐old adults in present analyses. Future work will extend to whole genome analysis to identify novel genomic drivers of SuperAging. [ABSTRACT FROM AUTHOR]

Background: In cognitively unimpaired (CU) older adults, the presence of a subjective cognitive decline (SCD) combined with evidence of abnormal b‐amyloid (Ab) is proposed as stage 2 of Alzheimer's disease (AD) by the NIA‐AA framework (Jack et al., 2018). However, the associations found between SCD and preclinical AD are inconsistent across studies, highlighting the importance of better understanding which specific SCD features are associated with either Ab or tau burden. Methods: The present study includes cross‐sectional data from 9 independent cohorts with a total of 7217 CU older adults (57% female), aged 69.34 (1.20) years, recruited from general and memory‐clinic populations. Ab and tau biomarkers were measured by positron emission tomography (PET) or cerebrospinal fluid (CSF). Using established cut‐offs, 28% of participants were Aβ+, and 12% were Aβ+T+ (approximately one‐third of the sample had available tau data). We examined four SCD‐plus criteria as well as the mean number of SCD criteria met (i.e., mean SCD‐severity) in relation to both biomarker status and levels in logistic/linear regressions adjusted for age and sex for each cohort. Summary statistics were extracted for meta‐analyses. Results: The overall frequency of stage 2 AD varied from 7‐16% [4‐26%] according to each SCD‐plus criterion endorsement. Only 1‐5% [0‐8%] of participants meeting the SCD‐plus criteria also had both high Aβ and tau burden (Fig.1). The presence of self‐reported memory decline (SMD), an associated concern/worry, and a higher mean SCD‐severity were each associated with high Ab (status and continuous). Only the latter was associated with high tau status (Fig.2). Onset of SCD within the last 5 years, and feeling of worse performance than same‐age peers, were not associated with AD biomarkers at a Bonferroni‐corrected threshold. Conclusions: Our results suggest that widespread endorsement of multiple SCD features is more powerful than a single criterion alone in identifying both Aβ and tau in CU older adults. We found that the isolated SCD criterion was particularly sensitive to elevated Aβ, even after adjustment for tau, supporting the power of SCD as a very early behavioral marker of preclinical AD. [ABSTRACT FROM AUTHOR]

Cerebrospinal fluid (CSF) levels of amyloid-β 42 (Aβ42) and tau have been evaluated as endophenotypes in Alzheimer's disease (AD) genetic studies. Although there are sex differences in AD risk, sex differences have not been evaluated in genetic studies of AD endophenotypes. We performed sex-stratified and sex interaction genetic analyses of CSF biomarkers to identify sex-specific associations. Data came from a previous genome-wide association study (GWAS) of CSF Aβ42 and tau (1527 males, 1509 females). We evaluated sex interactions at previous loci, performed sex-stratified GWAS to identify sex-specific associations, and evaluated sex interactions at sex-specific GWAS loci. We then evaluated sex-specific associations between prefrontal cortex (PFC) gene expression at relevant loci and autopsy measures of plaques and tangles using data from the Religious Orders Study and Rush Memory and Aging Project. In Aβ42, we observed sex interactions at one previous and one novel locus: rs316341 within SERPINB1 (p = 0.04) and rs13115400 near LINC00290 (p = 0.002). These loci showed stronger associations among females (β = - 0.03, p = 4.25 × 10-8; β = 0.03, p = 3.97 × 10-8) than males (β = - 0.02, p = 0.009; β = 0.01, p = 0.20). Higher levels of expression of SERPINB1, SERPINB6, and SERPINB9 in PFC was associated with higher levels of amyloidosis among females (corrected p values  0.38). In total tau, we observed a sex interaction at a previous locus, rs1393060 proximal to GMNC (p = 0.004), driven by a stronger association among females (β = 0.05, p = 4.57 × 10-10) compared to males (β = 0.02, p = 0.03). There was also a sex-specific association between rs1393060 and tangle density at autopsy (pfemale = 0.047; pmale = 0.96), and higher levels of expression of two genes within this locus were associated with lower tangle density among females (OSTN p = 0.006; CLDN16 p = 0.002) but not males (p ≥ 0.32). Results suggest a female-specific role for SERPINB1 in amyloidosis and for OSTN and CLDN16 in tau pathology. Sex-specific genetic analyses may improve understanding of AD's genetic architecture.

ImportanceThe strongest genetic risk factor for Alzheimer disease (AD), the apolipoprotein E (APOE) gene, has a stronger association among women compared with men. Yet limited work has evaluated the association between APOE alleles and markers of AD neuropathology in a sex-specific manner.ObjectiveTo evaluate sex differences in the association between APOE and markers of AD neuropathology measured in cerebrospinal fluid (CSF) during life or in brain tissue at autopsy.Design, setting, and participantsThis multicohort study selected data from 10 longitudinal cohort studies of normal aging and AD. Cohorts had variable recruitment criteria and follow-up intervals and included population-based and clinic-based samples. Inclusion in our analysis required APOE genotype data and either CSF data available for analysis. Analyses began on November 6, 2017, and were completed on December 20, 2017.Main outcomes and measuresBiomarker analyses included levels of β-amyloid 42, total tau, and phosphorylated tau measured in CSF. Autopsy analyses included Consortium to Establish a Registry for Alzheimer's Disease staging for neuritic plaques and Braak staging for neurofibrillary tangles.ResultsOf the 1798 patients in the CSF biomarker cohort, 862 were women, 226 had AD, 1690 were white, and the mean (SD) age was 70 [9] years. Of the 5109 patients in the autopsy cohort, 2813 were women, 4953 were white, and the mean (SD) age was 84 (9) years. After correcting for multiple comparisons using the Bonferroni procedure, we observed a statistically significant interaction between APOE-ε4 and sex on CSF total tau (β = 0.41; 95% CI, 0.27-0.55; P

BackgroundWorking memory (WM) is often assessed with serial order tests such as repeating digits backward. In prior dementia research using the Backward Digit Span Test (BDT), only aggregate test performance was examined.ObjectiveThe current research tallied primacy/recency effects, out-of-sequence transposition errors, perseverations, and omissions to assess WM deficits in patients with mild cognitive impairment (MCI).MethodsMemory clinic patients (n = 66) were classified into three groups: single domain amnestic MCI (aMCI), combined mixed domain/dysexecutive MCI (mixed/dys MCI), and non-MCI where patients did not meet criteria for MCI. Serial order/WM ability was assessed by asking participants to repeat 7 trials of five digits backwards. Serial order position accuracy, transposition errors, perseverations, and omission errors were tallied.ResultsA 3 (group)×5 (serial position) repeated measures ANOVA yielded a significant group×trial interaction. Follow-up analyses found attenuation of the recency effect for mixed/dys MCI patients. Mixed/dys MCI patients scored lower than non-MCI patients for serial position 3 (p

Objective: This study examined the effect of cognitive status, education, and sex on the association between subjective cognitive decline (SCD) and Alzheimer's disease (AD) biomarkers in non‐demented older adults. Methods: Vanderbilt Memory and Aging Project participants (n = 129), dementia or stroke free, completed fasting lumbar puncture, SCD assessment, and cognitive assessment. Cerebrospinal fluid (CSF) biomarkers for AD were analyzed. Linear regression models related SCD to CSF AD biomarkers and follow‐up models assessed interactions of SCD × cognitive status, sex, reading level, and education on AD biomarkers. Results: In main effect models, higher SCD was associated with more amyloidosis (p‐values <0.004). SCD was not associated with tau, p‐tau, or neurofilament light (NFL) levels (p‐values >0.38). SCD score interacted with cognitive status (p < 0.02), sex (p = 0.03), and education (p‐values <0.005) on amyloidosis. In stratified models, higher SCD was associated with more amyloid in cognitively unimpaired (p‐values <0.003), men (p = 0.0003), and higher education. No SCD score × reading‐level interaction was found (p‐values >0.51) though SCD related to amyloid markers in the higher reading‐level group (p‐values <0.004). Interpretation: Higher SCD was associated with greater cerebral amyloid accumulation, one of the earliest pathological AD changes. SCD appears most useful in detecting early AD‐related brain changes prior to objective cognitive impairment, in men, and those with higher quantity and quality of education and highlight the importance of considering these factors. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Plasma phosphorylated tau‐181 (p‐tau181) associations with global cognition and memory are clear, but the link between p‐tau181 with other cognitive domains and subjective cognitive decline (SCD) across the clinical spectrum of Alzheimer's disease (AD) and how this association changes based on genetic and demographic factors is poorly understood. METHODS: Participants were drawn from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and included 1185 adults >55 years of age with plasma p‐tau181 and neuropsychological test data. Linear regression models related plasma p‐tau181 to neuropsychological composite and SCD scores with follow‐up models examining plasma p‐tau181 interactions with cognitive diagnosis, apolipoprotein E (APOE) ε4 carrier status, age, and sex on cognitive outcomes. RESULTS: Higher plasma p‐tau181 level was associated with worse memory, executive functioning, and language abilities, and greater informant‐reported SCD. Visuospatial abilities and self‐report SCD were not associated with plasma p‐tau181. Associations were generally stronger in mild cognitive impairment (MCI) or dementia, APOE ε4 carriers, women, and younger participants. DISCUSSION: Higher levels of plasma p‐tau181 are associated with worse neuropsychological test performance across multiple cognitive domains; however, these associations vary based on disease stage, genetic risk status, age, and sex. Highlights: Greater plasma p‐tau181 was associated with lower cognition across most domains.Associations between p‐tau181 and cognition were modified by age and sex.Level of p‐tau181 was more strongly associated with cognition in people with mild cognitive impairment (MCI) and apolipoprotein E (APOE) ε4. [ABSTRACT FROM AUTHOR]

Background: The Apolipoprotein E ε4 (APOE‐ε4) allele is common in the population, but acts as the strongest genetic risk factor for late‐onset Alzheimer's disease (AD). Despite the strength of the association, there is notable heterogeneity in the population including a strong modifying effect of genetic ancestry, with the APOE‐ε4 allele showing a stronger association among individuals of European ancestry (EUR) compared to individuals of African ancestry (AFR). Given this heterogeneity, we sought to identify genetic modifiers of APOE‐ε4 related to cognitive decline leveraging APOE‐ε4 stratified and interaction genome‐wide association analyses (GWAS). Method: We leveraged a comprehensive harmonized cognitive dataset from nine well‐characterized aging and AD cohorts, representing African and European ancestries (total of 32,751 individuals, including 10,969 EUR ε4 carriers, 18,385 EUR non‐carriers, 1,495 AFR ε4 carriers, and 1,902 AFR non‐carriers). We then conducted APOE stratified and interaction GWAS and post GWAS analyses on longitudinal composite measures of memory, executive function, and language. To capture longitudinal cognitive trajectories, linear mixed effects models were employed, focusing on the rate of cognitive decline over time. Post GWAS analysis included eQTL analysis, gene‐set/pathway‐set analysis, and an assessment of genetic correlations. Result: We identified novel loci for baseline executive function performance including two that are specific to APOE‐ε4 carriers (rs28609108 on chromosome 9 and rs2959641 on chromosome 15) and one that is specific to non‐carriers (rs73072750 on chromosome 7). The effect sizes of these three loci remained consistent when subset by ancestry, achieving statistical significance in EUR, and nominal significance in AFR. Post GWAS eQTL analyses implicate the glutamate receptor subunit gene (GRIN3A) among APOE‐ε4 carriers, while the integrin gene (ITGB8). Additionally, both GRIN3A and ITGB8 have been previously implicated in AD/cognition GWAS, underscoring their relevance in the context of APOE‐ε4. Conclusion: Our study has shed light on several novel genetic factors that relate to late‐life cognitive performance in an APOE‐specific manner. These findings enrich our understanding of the genetic landscape influencing cognitive decline. Further research is imperative to unravel how these genetic variations affect biological processes and the potential in guiding therapeutic strategies. [ABSTRACT FROM AUTHOR]

A symptom of mild cognitive impairment (MCI) and Alzheimer's disease (AD) is a flat learning profile. Learning slope calculation methods vary, and the optimal method for capturing neuroanatomical changes associated with MCI and early AD pathology is unclear. This study cross-sectionally compared four different learning slope measures from the Rey Auditory Verbal Learning Test (simple slope, regression-based slope, two-slope method, peak slope) to structural neuroimaging markers of early AD neurodegeneration (hippocampal volume, cortical thickness in parahippocampal gyrus, precuneus, and lateral prefrontal cortex) across the cognitive aging spectrum [normal control (NC); (n=198; age=76±5), MCI (n=370; age=75±7), and AD (n=171; age=76±7)] in ADNI. Within diagnostic group, general linear models related slope methods individually to neuroimaging variables, adjusting for age, sex, education, and APOE4 status. Among MCI, better learning performance on simple slope, regression-based slope, and late slope (Trial 2-5) from the two-slope method related to larger parahippocampal thickness (all p-values