Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Vascular dysfunction contributes to Alzheimer disease (AD) and related dementias (ADRDs), but the underlying mechanisms remain unclear. Previous studies link midlife hemostasis and platelet aggregation measures to late-life dementia risk. We aimed to determine whether platelet aggregation in midlife is associated with imaging markers of AD pathology. METHODS:F-flortaucipir) PET uptake in dementia-free, middle-aged adults from the Framingham Heart Study. Co-primary outcomes included amyloid and tau uptake in AD-vulnerable regions. We also examined an MRI-based cortical thickness signature of AD risk as a secondary outcome. We used multivariable regression models adjusted for demographic and clinical factors, considering potential nonlinear associations. RESULTS:< 0.035), consistent with a neurodegenerative pattern. DISCUSSION/CONCLUSIONS:Our findings indicate that platelet aggregation is linked to PET and MRI markers of AD pathology as early as midlife. These findings support further investigation of platelet-mediated mechanisms in AD pathogenesis.

OBJECTIVE:People with migraine have a higher prevalence and severity of insomnia. We examined the relationship between insomnia severity and migraine-related disability (MIDAS) and migraine-specific quality of life (MSQv2.1). METHODS:We conducted a post-hoc analysis of a pilot randomized controlled study assessing the RELAXaHEAD application in those with insomnia and comorbid migraine. Descriptive statistics were used to summarize demographic and clinical characteristics. Linear mixed model analysis was conducted to evaluate Insomnia Severity Index (ISI) as a predictor of each MSQv2.1 domain and MIDAS. RESULTS:Forty-two participants completed baseline and at least one follow-up survey. Mean age was 43.8 years (SD 12.6) and the majority (85.7%) were female. Most participants (81.0%) had severe migraine-related disability (median baseline MIDAS, 32 (IQR 52)). Over half (54.8%) of participants had moderate clinical insomnia (mean baseline ISI, 18.5 (SD 4.6)). Baseline median MSQv2.1 scores were 44.3 (IQR 31.4) for Role Function-Restrictive (RFR), 65.0 (IQR 45.0) for Role Function-Preventive (RFP), and 46.7 (IQR 46.7) for Emotional Function (EF). The effect of ISI on MIDAS was statistically significant (rate ratio (RR)=1.10, p < 0.05, 95%CI [1.028, 1.171], meaning each one-point increase in ISI was associated with a 10% higher MIDAS score). Additionally, a 1-point increase in ISI was associated with a decrease of 1.2 points in MSQ-RFR (B=-1.205, p = 0.001),1.0 point in MSQ-RFP (B=-0.981, p = 0.020), and 1.4 points in MSQ-EF (B=-1.66, p = 0.001). CONCLUSIONS:Our study revealed significant associations between insomnia severity and migraine-related disability and quality of life, highlighting the importance of prevention and sleep intervention for patients with migraine.

INTRODUCTION/BACKGROUND:Sleep, depression, stress, and neighborhood support are independently linked to cognition, but how these factors interact when sleep quality is poor remains understudied. METHODS:We analyzed cross-sectional baseline data from 233 adults aged ≥ 65 years in the Aging Adult Brain Connectome study. Sleep quality, depressive symptoms, stress, and neighborhood support were assessed with validated scales, and cognition was measured using the Preclinical Alzheimer's Cognitive Composite (PACC). Models tested two- and three-way interactions, adjusting for sociodemographics. RESULTS:Poor sleep quality was associated with lower PACC scores (β = -0.57, p = 0.002). This association was even more pronounced in older adults who also had depressive symptoms (β = -0.09, p < 0.001) or increased stress (β = -0.31, p < 0.001). This effect was attenuated by greater neighborhood support (interaction estimates 0.007-0.021, all p ≤ 0.014). DISCUSSION/CONCLUSIONS:Poor sleep quality was associated with lower cognition, compounded by psychosocial burden and buffered by neighborhood support. HIGHLIGHTS/CONCLUSIONS:Poor sleep quality worsened late-life cognitive performance in older adults. Depressive symptoms and stress further worsened the effect of poor sleep on cognitive performance. Neighborhood support buffered negative sleep-psychosocial impacts on cognitive performance.

INTRODUCTION/BACKGROUND:Sleep disturbances are common in older people with cognitive impairment, potentially contributing to negative outcomes. A core outcome set (COS) is required to reduce heterogeneity in clinical trials and promote the development of high-quality evidence to support clinical management. METHODS:A multi-stage mixed methods study was conducted in accordance with The Core Outcome Set Standards for Development. RESULTS:A systematic review identified 287 sleep outcomes from previous clinical trials. Qualitative interviews ensured the COS was informed by what matters most to people with cognitive impairment and their caregivers. A modified Delphi process identified nine outcomes for the COS: total sleep time, sleep onset latency, wakefulness after sleep onset, number of night-time awakenings, sleep efficiency, and measures of sleep quality, daytime sleepiness, cognition, and mood. DISCUSSION/CONCLUSIONS:This COS will support researchers to produce more reliable and coherent trial data to guide the management of sleep disturbances in people with neurodegenerative cognitive impairment. HIGHLIGHTS/CONCLUSIONS:Evidence is lacking regarding the treatment of sleep disturbances in people with cognitive impairment. Heterogeneity of reported outcomes in clinical trials limits data synthesis. A qualitative analysis established what matters most to people with cognitive impairment and their caregivers when determining treatment effectiveness. A Delphi panel of experts agreed upon a core outcome set. This core outcome set will improve the reliability and comparability of data from future trials.

Obstructive sleep apnea (OSA) exerts pathogenic effects through a combination of sleep fragmentation (SF) and intermittent hypoxia (IH). The mechanisms through which sleep disruption impacts memory might arise by investigating disruption of specific sleep stages and, when such disruption occurs through OSA, by evaluating the individual contributions of SF and IH. Given region-specific EEG slow activity during non-REM sleep has been associated with overnight declarative, motor and spatial memory formation, we investigated the effects of disrupting slow wave sleep (SWS) on a virtual maze navigation task. Thirty three participants (24 male, 56 years old [range 28-68 years] with OSA (baseline AHI4%>20/hour) who were habitually well-treated and adherent to CPAP completed 3 timed trials on a 3D spatial maze before and after polysomnographically (PSG) recorded sleep. We restricted CPAP withdrawal to SWS through real-time monitoring of the PSG under three conditions: 1) stable-SWS on therapeutic CPAP, 2) SWS-CPAP withdrawal containing SF and IH, and 3) SWS-CPAP withdrawal with supplemental oxygen containing SF with reduced IH. SWS-specific CPAP withdrawal (with or without supplemental oxygen) did not significantly impact EEG slow oscillation or spatial navigational memory, despite effectively reducing %SWS and SWS bout length. Greater regional EEG slow oscillation (0.6-1Hz), but not delta (1-4Hz) activity, was associated with improvements in overnight memory during stable SWS in the CPAP condition. These observations suggest that slow oscillations may be important for overnight memory processing, and sleep disruptions of sufficient magnitude to reduce slow oscillations may be required to capture demonstrable change in spatial navigation performance.

INTRODUCTION/BACKGROUND:Many health life exposure factors (LEFs) influence cognitive decline and dementia incidence, but their relative importance to episodic memory (an early indicator of cognitive decline) among diverse older adults is unclear. We used machine learning to rank LEFs for memory performance in a large and diverse US cohort. METHODS:Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) and Study of Healthy Aging in African Americans (STAR), participants underwent neuropsychological testing and answered questionnaires about multiple LEFs. XGBoost and Shapley Additive exPlanation values ranked the importance of factors influencing cross-sectional episodic memory in the full sample and by sex and ethnic group. RESULTS:Among 2245 adults (mean age: 74 years; range 54-90), age, sex, education, volunteering, income, vision, hearing, sleep, and exercise contributed to memory performance regardless of group stratification. DISCUSSION/CONCLUSIONS:This innovative methodology can help identify risk factors important for memory performance and guide future dementia risk reduction interventions among older adults. HIGHLIGHTS/CONCLUSIONS:This work uses a regression tree machine learning model (XGBoost) with highly interpretable Shapley Additive exPlanation values to analyze impacts of 12 life exposure factors plus age, sex and ethnoracial identity on episodic memory outcome. This approach has valuable properties, including the ability to implicitly account for variable interactions, non-linear relations with outcome, and missing values. Age, sex, education, income, volunteering, exercise, hearing and vision, and sleep (quality and duration) have important impacts on memory outcome in a combined model and in stratified models regardless of ethnoracial identity. We also demonstrate individualized models for subgroups of participants, showing how life exposure factors vary in importance between divergent populations and suggesting an approach to personalized interventions. This approach can be valuable for both policy decisions and individualized interventions to support healthy cognitive aging.

Poor cardiovascular health is strongly linked to increased risk of cognitive impairment and Alzheimer's disease and related dementias. This commentary discusses Yang and associates' work on the associations between cardiovascular health in middle age, as defined by Life Essential 8 scores, and later digital cognitive performance and incident Alzheimer's disease. We examine the strengths and weaknesses of their study within the broader research context. We emphasize the potential significance of sleep and stress the need for longitudinal studies incorporating robust neuropsychiatric methodologies, advanced neuroimaging techniques, and diverse participant samples to enhance the reliability and generalizability of results.