Dana Greenia

Amyloid imaging and cognitive decline in nondemented oldest-old: The 90+ Study

The goal of this study was to examine cross‐sectional and longitudinal associations between cognitive performance and beta amyloid (Aβ) load determined by florbetapir F18 positron emission tomography (PET) in nondemented oldest‐old.

Lower likelihood of falling at age 90+ is associated with daily exercise a quarter of a century earlier: The 90+ Study

Objective to explore the relationship between risk of falling at age 90+ and prior physical activity at age 60-70s. Design population-based cohort study (The 90+ Study). Setting California retirement community. Participants of 1596 cohort members, 1536 had both falls and prior activity data. Mean age = 94 years; 78% female; 99% Caucasian. Methods time spent in active physical activity was self-reported in 1980s; medical history, medication, assistive devices, residence type, and falls (outcome) was collected in 2000s. Activity/fall relationships were assessed using logistic regression. Results falls were reported by 52% of participants, recurrent falls by 32%, and severe injury by 21% of fallers. In univariate analyses risk of falling at age 90+ was significantly related to medical history (heart disease, TIA/stroke, arthritis, vision disease, depression, dementia), medication use (hypnotics, anti-psychotics, anti-depressants), use of assistive devices (cane, walker, wheelchair), residence type (living with relatives, sheltered living), and source of information (self-report vs informant). Risks of falling and recurrent falls at age 90+ were 35-45% lower in those reporting 30+ minutes/day of active physical activity at age 60-70s compared with no activity. The odds ratio of falling was 0.65 (95% CI = 0.44-0.97) for 30-45 minutes/day and 0.64 (0.44-0.94) for 1+ hour/day adjusting for age, sex, medical history (stroke/TIA, vision disease, depression), use of assistive devices, and source of information. Conclusions and Relevance falls are extremely common among the oldest-old and a significant proportion lead to severe injury. This work is the first to show an association between exercise at age 60-70s and lower risk of falling at age 90+.

Abstract TP187: 24-hour Ambulatory Blood Pressure, Cognitive Performance, and Cerebral Microbleeds in the Elderly

Introduction: Multiple studies suggest a role for blood pressure (BP) variability and nocturnal BP dipping in the development of cerebrovascular disease and cognitive impairment. We analyzed cross-...

PET AMYLOID IMAGING WITH FLORBETAPIR AND COGNITION IN THE OLDEST-OLD: THE 90+ STUDY

however, largely varies across monocenter studies, and results from multicenter studies are still scarce. In the present study, we assessed the robustness and diagnostic utility of functional connectivity (FC) and the amplitude of low-frequency fluctuations (ALFF) derived from multicenter rs-fMRI in a large prospective multicenter cohort using identical scanning p rotocols and high-level standardized procedures. Methods: Baseline data of N1⁄4247 participants from the DZNE Longitudinal Cognitive Impairment and Dementia (DELCODE) study were included in the analysis. FC and fALFF were calculated from the low-frequency signal fluctuations of the rsfMRI time series and averaged using a functionally defined atlas. Elastic-net penalized logistic regression models were applied to differentiate between individuals with subjective cognitive decline (SCD), amnestic mild cognitive impairment (MCI), or AD dementia and cognitively normal controls. Results were evaluated using repeated tenfold cross-validation. Results: Quality control results showed a more homogeneous temporal signal-to-noise ratio (tSNR) across centers than in a previous multicenter rs-fMRI study using heterogeneous scanning protocols (Fig.1). Resting state FC reached significant group discrimination only for the comparison of AD dementia cases with healthy controls, but not for the other diagnostic groups (Fig.2). AD dementia cases showed alterations in a large range of intrinsic resting state networks, including the default mode and salience networks, but also executive and language networks. When groups were stratified according to their CSF amyloid status that was available in a subset of cases, diag-

AMYLOID BURDEN DOES NOT DIFFERENTIATE COGNITIVE STATUS AMONGST THE OLDEST OLD: THE 90+ STUDY

and posterior cingulate cortex (Figure 2A). For comparison, no significant regions were observed using a whole cortex average of b-amyloid burden (Figure 2B). Conclusions: Multivariate, cross-correlation analyses can uncover complex brain patterns not found with univariate statistical analysis approaches. These results support the notion that it is the spatially distributed, rather than focal, accumulation of b-amyloid that is associated with metabolic dysfunction. Future work will expand this analysis to identify the pattern of b-amyloid maximally related to metabolic connectivity.