OBJECTIVES:Lifestyle activity engagement in later life may protect against dementia, but studies have often been limited to short follow-up periods and predominantly White samples. We examined activity variety and frequency as predictors of incident dementia, leveraging 15 years of linked longitudinal insurance claims data in the Baltimore Experience Corps Study (BECS). METHODS:Participants were 482 individuals from BECS (2006-2013) with linked insurance claims (mean age=68.2, 84% women, 95% Black/African American). Participants self-reported baseline engagement in 28 activities. We calculated the number of unique activities (activity variety) and average frequency of engagement across reported activities (activity frequency). Incident dementia (2008-2022) was ascertained from CMS and private claims using the Bynum-EM algorithm. We used Cox proportional hazards models, adjusting for age and intervention group, and tested multiple follow-up periods (5-year, 15-year). RESULTS:The average baseline variety was 18.8 activities (SD = 3.3) and frequency was 13.1 days/month (SD = 3.2). For the 15-year follow-up only, higher activity variety was associated with lower risk of incident dementia (HR=.94, 95% CI: 0.89-0.99), equivalent to about a 6-month delay in diagnosis per additional activity. This association was attenuated after adjusting for additional demographics (e.g., sex, education), prevalent health conditions, and depression (HR=.96, 95% CI: 0.90-1.01). Activity frequency was not significant in any model. DISCUSSION:Higher activity variety, but not frequency, modestly predicted lower dementia risk over 15 years in a sample of primarily Black older adults. Findings suggest that engagement in a range of activities, rather than more frequent engagement in limited activities, may elicit greater cognitive benefits.

INTRODUCTION:Blue spaces (i.e., water bodies) may benefit cognitive health depending on their uses and surrounding spatial context. We examined associations between blue spaces and incident dementia in the Cardiovascular Health Cognition Study, and specifically within Pittsburgh, given its industrial uses of blue spaces. METHODS:Participants were 2924 adults (Pittsburgh: n = 651) ≥65 years of age. Dementia was clinically adjudicated (1992-1999). Water density was measured using both 1 km radial buffers and U.S. Census tracts. RESULTS:In Pittsburgh only, greater buffer-level blue space predicted a higher risk of mixed/vascular dementia (highest vs lowest tertile: hazard ratio [HR] = 2.87, 95% confidence interval [CI]: 1.43-5.74), but not Alzheimer's disease (p > 0.05). This was attenuated adjusting for individual/neighborhood confounders (HR = 2.65, 95% CI: 0.99-7.07). Tract-level associations were attenuated but significant after adjustment. DISCUSSION:Blue space was related to vascular dementia risk after accounting for social context and using more personalized buffer-level measures. Future studies should carefully consider spatial units and differentiate blue spaces by historical uses. HIGHLIGHTS:Examined associations between nearby blue spaces and incident dementia. Tested multiple spatial units (buffer, tract) and separately for the Pittsburgh site. Blue space density was not related to dementia risk in overall sample. Greater blue space density predicted a higher risk of dementia for the Pittsburgh site. Associations were attenuated after adjusting for neighborhood confounders.

Fatigue is prevalent in later life and may increase dementia risk independent of health conditions. Yet, existing epidemiologic studies include samples that are not nationally representative of U.S. older adults. These studies have also not examined fatigue in combination with current physical activity level, which is important because higher fatigue ratings may also stem from a more active lifestyle that could lower dementia risk. We examined whether self-reported fatigue, both independently and jointly with self-reported physical activity, was associated with 10-year risk of incident dementia in U.S. older adults. Participants were from the National Health and Aging Trends Study (2011-2021, N = 5,167), a population representative cohort of U.S. Medicare beneficiaries. Fatigue was self-reported as having low energy in the past month that interfered with activities (yes/no). Participants also reported past-month engagement in any vigorous activity that increased their heart rate (e.g., working out; yes/no). Probable dementia cases were ascertained using cognitive testing and proxy reporting. Analyses included discrete-time proportional hazards models with sample weighting to account for survey design and adjusted for baseline age, sex, race/ethnicity, education, BMI, number of health conditions, smoking status, social isolation, and depressive symptoms. Twenty-nine percent of participants reported fatigue. Frequencies of combined fatigue and activity groups included: “active/no fatigue” (31%), “active/fatigued” (8%), “inactive/no fatigue” (40%), “inactive/fatigued” (21%). There were 1,089 incident cases of probable dementia for up to 10 years of follow-up (M±SD = 5.4±3.6 years). Individuals reporting fatigue (vs. no fatigue) had a 16% greater risk of incident dementia after full covariate adjustment (HR = 1.16, 95% CI: 1.01, 1.34, p = .041). Compared to the “active/no fatigue” group, the “inactive/fatigued” group had a 40% greater risk of incident dementia after adjustment (HR = 1.40, 95% CI: 1.16, 1.69, p = .001), but risk did not significantly differ for “active/fatigued” and “inactive/no fatigue” groups (p’s>.05). Fatigue may be a signal of increased risk of incident dementia in U.S. older adults, independent of depressive symptoms and other health characteristics. Individuals reporting both fatigue and inactivity had the highest risk of dementia, suggesting that fatigue may be a symptom of underlying pathological processes, especially among those with low activity levels.

This study seeks to address the feasibility of a novel Traumatic Brain Injury (TBI) intervention optimized for adults with a remote history of TBI by determining the short-term impact on brain, mood, body, lifestyle activity and cognition, of an immersive 3-dimensional (3-D) computer game. The game requires one to help a dolphin, Bandit, through the ocean to catch fish and avoid getting bitten by sharks, thereby exercising and integrating complex cognitive-motor processes for pro-social goal. Here, we focus on whether this activity impacted subregions of the hippocampus related to verbal and spatial memory formation. During this 3-month randomized, controlled trial (RCT), we compared weekly performance on a complex cognitive-motor game, called “Bandit” (intervention) to a Successful Aging Program (active control) in those with history of TBI on Alzheimer's Disease Related Dementias -related brain biomarkers, and specifically, high-resolution hippocampal volumetry of subregions. A total of 23 participants were enrolled, with a mean age of 60.3 years in the intervention group and 57.6 years in the control group, 14 completed a brain MRI at baseline and 8 at follow-up. Of these, There were no statistically significant group differences in age, sex, education, or race. There was higher MRI-specific drop-out at follow-up in the active control condition ( N  = 4) vs. Bandit intervention group ( N  = 2). Participants in the Bandit intervention enjoyed the game and reported no adverse effects. Pre-post MRI results showed significant intervention-specific increases in volumes in the left subiculum ( p  = 0.043) and CA3 subregions ( p  = 0.020) of the hippocampus, both of which are related to spatial and verbal memory and risk for ADRD. No significant differences were observed in the left CA1, CA2, or dentage gyrus or any right subregions. Our results confirm that an immersive game involving complex motor activities for pro-social benefit was enjoyed and well tolerated. Gamers with a history of TBI demonstrated improved subicular and CA3 volumes of the left hippocampus relative to active controls. These promising results have implications for early intervention designed for social, physical and cognitive engagement in single player and group player settings among those at risk for mild cognitive impairment and ADRD.

BACKGROUND:This study seeks to address the feasibility of a novel Traumatic Brain Injury (TBI) intervention optimized for adults with a remote history of TBI by determining the short-term impact on brain, mood, body, lifestyle activity and cognition, of an immersive 3-dimensional (3-D) computer game. The game requires one to help a dolphin, Bandit, through the ocean to catch fish and avoid getting bitten by sharks, thereby exercising and integrating complex cognitive-motor processes for pro-social goal. Here, we focus on whether this activity impacted subregions of the hippocampus related to verbal and spatial memory formation. METHODS:During this 3-month randomized, controlled trial (RCT), we compared weekly performance on a complex cognitive-motor game, called "Bandit" (intervention) to a Successful Aging Program (active control) in those with history of TBI on Alzheimer's Disease Related Dementias -related brain biomarkers, and specifically, high-resolution hippocampal volumetry of subregions. RESULTS:A total of 23 participants were enrolled, with a mean age of 60.3 years in the intervention group and 57.6 years in the control group, 14 completed a brain MRI at baseline and 8 at follow-up. Of these, There were no statistically significant group differences in age, sex, education, or race. There was higher MRI-specific drop-out at follow-up in the active control condition (N = 4) vs. Bandit intervention group (N = 2). Participants in the Bandit intervention enjoyed the game and reported no adverse effects. Pre-post MRI results showed significant intervention-specific increases in volumes in the left subiculum (p = 0.043) and CA3 subregions (p = 0.020) of the hippocampus, both of which are related to spatial and verbal memory and risk for ADRD. No significant differences were observed in the left CA1, CA2, or dentage gyrus or any right subregions. CONCLUSIONS:Our results confirm that an immersive game involving complex motor activities for pro-social benefit was enjoyed and well tolerated. Gamers with a history of TBI demonstrated improved subicular and CA3 volumes of the left hippocampus relative to active controls. These promising results have implications for early intervention designed for social, physical and cognitive engagement in single player and group player settings among those at risk for mild cognitive impairment and ADRD.

Community mobility has been defined as one's ability to access and interact with different areas within their larger spatial environment.1 Diminished community mobility has been associated with deleterious health outcomes including mortality.2 Understanding the associations between modifiable risk factors and community mobility may inform interventions to maintain independence in older adults. Fatigability can be operationalized as either perceived or performance related.3 Greater perceived fatigability (what one thinks they can do) has been associated with lower community mobility when using a validated self-reported life-space questionnaire.4, 5 We assessed whether performance fatigability (what one can do), the quantification of one's slowing down due to fatigue, was associated with Global Positioning System (GPS)-measured community mobility. Participants (n = 142) were drawn from the Program to Improve Mobility in Aging (PRIMA) Study (N = 249) randomized intervention trial (Supplementary Methods S1). Details on PRIMA design, participants, and GPS protocols were published.6, 7 Briefly, PRIMA assessed the effects of a standard physical performance program (control) and the standard program plus a coordination and timing program (treatment) on mobility.6 Data presented here were from the baseline, pre-intervention visit. The Pittsburgh Performance Fatigability Index (PPFI)8 is an accelerometry-based performance fatigability measure that quantifies performance decrement (i.e., slowing down) by comparing the area under the observed cadence–time curve to a hypothetical area under the curve in the absence of fatigue (higher PPFI score = greater fatigability) during a walking task.8 In PRIMA, PPFI was applied to a 6-minute walk test (Supplementary Methods S1). From July 2016 to October 2019, participants were asked to carry a GPS device (iBlue 747: TSI: Hsinchu, Taiwan or Columbus V990: Columbus: Germany; <5% carried the iBlue device) for seven consecutive days.7 To assess the attributes of community mobility, GPS data were used to calculate time-weighted standard deviational ellipses (SDE, higher area = greater community mobility), median hours outside of home (TOH), percent TOH, median maximum distance from home (MDH), and overall MDH.7 First, we assessed baseline characteristics across tertiles of SDE area using chi-square tests for categorical variables and analysis of variance (ANOVA) tests for continuous variables. Next, ordinal logistic regression models quantified the association between 1% higher PPFI score and tertiles of GPS measures adjusted for self-reported age and sex. Parallel regression assumptions were assessed using the Brant test. All associations were considered statistically significant if p < 0.05. All analyses were conducted in R version 4.3.1 (R Foundation for Statistical Computing, Vienna, Austria). Participants were 68% women, 85% White, 10% Black, 50% had higher than college education, and mean (±standard deviation) age of 77.0 ± 6.5 years (Table 1). PPFI scores ranged from 0% to 12.7%. For each 1% higher PPFI score, odds of being in a higher tertile of SDE area was lower by 18% (Odds Ratio [OR] = 0.82 [95% Confidence Interval (CI): 0.72, 0.94]) and odds of being in a higher tertile of median maximum distance from home was lower by 12% (OR = 0.88 [95% CI: 0.77, 0.99]) (Figure 1). PPFI was not associated with median hours outside the home, overall percentage of time outside the home, or overall maximum distance from home (Figure 1). We provided preliminary, novel evidence that greater performance fatigability, measured by PPFI, was associated with lesser spatial area of activity and distance traveled from one's home, but not the time spent outside of the home. Further, a measure that represents daily habits (median maximum distance from home) was associated with performance fatigability, but a measure representing a single day of farthest travel was not (overall maximum distance from home which may be skewed by single days with a large distance traveled).7 Current findings support and strengthen prior evidence that greater perceived fatigability was also associated with more restricted community mobility.4, 5 Our results suggest that performance fatigability may be primarily restricting the day-to-day distance traveled into one's community. Generalizability of our findings is somewhat limited as the included sample was primarily White and well-educated. Also, data regarding participants' driving ability were not assessed.7 Another limitation was the exclusion of almost one-third of GPS users from analysis due to logistical or compliance issues. Future work should explore facilitators and barriers to effective use. The strengths of this study include the use of objective data collection methods with GPS technology and accelerometry-based performance fatigability. Our findings reveal emerging cross-sectional evidence that greater performance fatigability may be a unique clinical indicator of less real-world community mobility. Future work should be conducted in a larger, more diverse sample controlling for demographic, health, and social characteristics related to community mobility. BTS—Conceptualization; formal analysis; writing—original draft; KDM—Conceptualization; formal analysis; writing—review and editing; YQ—Methodology; writing—review and editing; JSB—Funding acquisition; conceptualization; investigation; writing—review and editing; ALR—Funding acquisition; conceptualization; investigation; supervision; writing—review and editing; NWG—Methodology; supervision; writing—review and editing. The programming code to calculate PPFI for noncommercial purposes can be requested from the developer (NWG). The authors declare no conflicts of interest. This work was supported by the National Institute on Aging (NIA) at the National Institutes of Health (grant numbers R01AG057671 and R21AG054666 to ALR; R01AG045252 and K24AG057728 to JSB) and the Pittsburgh Pepper Center (NIA P30AG024827). The Epidemiology of Aging training grant at the University of Pittsburgh (NIA T32 AG000181) supported BTS and KDM. None. Supplementary Methods S1. Derivation of the Analytic Sample from Baseline Enrollment in the Program to Improve Mobility in Aging (PRIMA). Supplementary Methods S1. Calculation of the Pittsburgh Performance Fatigability Index (PPFI) for the 6-minute Walk Test. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Abstract Neighborhood socioeconomic resources and walkability (e.g., proximity of services/amenities) may promote health in later life by encouraging physical activity. Yet, structural racism (e.g., redlining) has caused Black Americans to disproportionately reside in more disadvantaged neighborhoods. We examined whether neighborhood socioeconomic disadvantage, both independently and jointly with neighborhood walkability, was cross-sectionally associated with objective step activity in non-Hispanic Black older residents of Baltimore City, MD. Participants were from the Baltimore Experience Corps Trial at baseline (n=168, mean age=67.0±5.5). Neighborhood measures included validated indices of Census tract-level walkability (e.g., transit access, street connectivity, service/commercial density) and socioeconomic disadvantage (e.g., poverty, unemployment). Individuals were further categorized into combined walkability/disadvantage groups using median splits of each index: low walkability/low disadvantage (40%), high walkability/low disadvantage (7%), high walkability/high disadvantage (46%), low walkability/high disadvantage (8%). Average daily step activity was measured using an ankle-worn monitor (mean=4.3 wear days). Linear regression was used to examine associations with step activity adjusted for age, gender, and education. Being in the highest (vs. lowest) tertile of disadvantage was associated with 1513 fewer average steps per day (95% CI: -2873,-153). While walkability was not independently associated with step activity (p>.05), the high walkability/high disadvantage group had an average 1381 more steps per day (95% CI: 204,2558) compared to the low walkability/high disadvantage group. Higher neighborhood socioeconomic disadvantage was linked with lower physical activity for non-Hispanic Black older residents of Baltimore City. Yet, positive neighborhood attributes like walkability may buffer against socioeconomic disadvantage, potentially by providing access to services/amenities that promote activity.

Abstract Neighborhood blue spaces (e.g., lakes, rivers, other water sources) are underexplored contributors to cognitive aging that may act by promoting recreation and mental health. Yet, benefits may vary by historical use and surrounding spatial context of water sources. We examined associations between neighborhood blue spaces and risk of incident dementia in community-dwelling older adults in Pittsburgh, PA. Participants were 655 adults ≥65 years old from the Cardiovascular Health Cognition Study (CHCS; 1992-1999) living in Pittsburgh/Allegheny County, PA. Baseline blue space was measured as the Census tract-level percentage of open water from the 1992 National Land Cover Dataset, stratified into groups incorporating water source: none (0%), low (.003-.04%, smaller water sources), and high (>.04%, major rivers). Time to dementia diagnosis was clinically adjudicated from a neurological exam, neuropsychological examinations, medical records, and proxy reporting across a median 6.2 years (n=103 cases, 16%). Cox models were adjusted for individual age, sex, race, education, income, and lifetime occupation. Greater blue space was associated with higher risk of all-cause dementia (low vs. none: HR = 1.74, 95% CI: 1.26, 2.41 high vs. none: HR = 2.08, 95% CI: 1.45, 2.98). Contrary to our hypothesis, neighborhood blue space was linked to increased risk of dementia for residents of Pittsburgh, PA. Historical industrialization and clustering of lower income neighborhoods along Pittsburgh’s main rivers will be discussed as potential contributors to this finding. Future work will capitalize on the geographic diversity of CHCS by comparing these analyses with more rural/suburban clinic sites (Winston-Salem, NC; and Hagerstown, MD).

INTRODUCTION:Neighborhood environments may promote neurocognitive health in part by providing amenities that encourage physical activity. We examined associations between quantity of walkable facilities, including specifically physical activity facilities (e.g., gyms, recreation centers), with risk of incident dementia. METHODS:Participants included 2923 adults ≥ 65 years old from the Cardiovascular Health Cognition Study (1992-1999), with clinically adjudicated dementia classified over a median 6.0 years of follow-up. Walkable facilities were measured within 1 km (Euclidean) of home. Self-reported baseline physical activity was considered a moderator. RESULTS:In adjusted Cox models, participants with ≥ 2 (vs. 0) physical activity facilities had reduced risk of mixed/vascular dementia, but not Alzheimer's disease, particularly after excluding individuals in the bottom 20th percentile of physical activity (hazard ratio = 0.56, 95% confidence interval: 0.35-0.89). DISCUSSION:Neighborhood amenities that encourage physical activity may mitigate dementia risk via improved vascular health, especially for individuals with sufficient baseline mobility to use these resources. HIGHLIGHTS:We examined associations between nearby walkable facilities and incident dementia. Facilities within 1 km were counted via the National Establishment Time Series Database. More physical activity facilities predicted lower risk of mixed/vascular dementia. No associations were found between walkable facilities and incident Alzheimer's disease.

Background We examined the relationship between global positioning system (GPS) indicators of community mobility and incident hospitalizations, emergency department (ED) visits, and falls over 1-year in community-dwelling older adults.Methods We performed a secondary analysis of a randomized trial investigating a physical therapy intervention to improve mobility in older adults. One hundred and forty-eight participants (mean age: 76.9 & PLUSMN; 6.2 years; 65% female) carried a GPS device following the postintervention visit. Over 1-year, new hospitalizations, falls, and ED visits were reported. GPS indicators of community mobility included the median area and compactness of the standard deviation ellipse (SDE), the median percentage of time spent outside of home (TOH), and median maximum distance from home. Generalized linear models assessed the association between 1-year risk of outcomes and GPS measures adjusted for age, race, gender, body mass index, comorbidity burden, and fall history.Results The mean & PLUSMN; standard deviation of the median SDE area was 4.4 & PLUSMN; 8.5 km2, median SDE compactness 0.7 & PLUSMN; 0.2, median percentage TOH 14.4 & PLUSMN; 12.0%, and median maximum distance from home was 38 & PLUSMN; 253 km. Each 5% increase in median percentage TOH was associated with a 24% lower risk of hospitalization (incident rate ratio = IRR = 0.76, 95%CI: 0.61-0.95; p = .01). The association persisted after covariate adjustment (IRR = 0.78, 95%CI: 0.63-0.98; p = .03). No significant associations appeared for any GPS indicators with incident falls or ED visits.Conclusions Increased TOH was associated with a lower risk of incident hospitalization over 1 year among community-dwelling older adults. Restricted community mobility may be an indicator of activity limitations related to future health outcomes, but further study is warranted.

Abstract Studying the impacts of neighborhoods on health exposures and outcomes has seen increased attention over the last few decades. Neighborhoods can describe where individuals work, live, and recreate in granular detail, facilitating our understanding of activity spaces throughout the lifecourse. However, a plethora of studies in neighborhood health, especially among older adults treat these spatial units as statistically independent. Most research in this domain fails to capture the potential influence of surrounding neighborhoods on health exposures and outcomes in the target neighborhood. Many of these studies also fail to check for residual spatial autocorrelation/dependence of modeling results, which may violate the assumption of independence that is fundamental in statistics. The explanatory power of regression models may also improve by accounting for the spatial dependence of the variables in question. We present conceptual examples (e.g., blue/green spaces, neighborhood socioeconomic status, and other social determinants of health) of spatial regression models that consider the influence of nearby neighborhoods on the dependent variable of interest. We also highlight the need to consider neighborhoods that are not adjacent since individuals may interact with neighborhoods farther away more often than those immediately adjacent. We then present case studies of modeling neighborhood and environmental predictors of cognitive outcomes of older adults in the Cardiovascular Health Study (CHS). Emphasis will also be on modeling lifecourse exposures. Our work highlights the power of spatial models to capture spillover and protective effects, which can greatly improve our understanding of older adult activity spaces and health across the lifecourse.

BackgroundAir pollution is a modifiable risk factor for dementia. Yet, studies on specific sources of air pollution (i.e., toxic chemical emissions from industrial facilities) and dementia risk are scarce. We examined associations between toxicity-weighted concentrations of industrial pollution and dementia outcomes among a large, multi-site cohort of older adults.MethodsParticipants (n = 2770) were ≥ 65 years old (Mean = 75.3, SD = 5.1 years) from the Cardiovascular Health Cognition Study (1992–1999). Toxicity-weighted concentrations were estimated using the Risk Screening Environmental Indicator (RSEI) model which incorporates total reported chemical emissions with toxicity, fate, and transport models. Estimates were aggregated to participants' baseline census tract, averaged across 1988–1992, and log2-transformed. Dementia status was clinically adjudicated in 1998–1999 and categorized by subtype (Alzheimer's, vascular, mixed). We assessed whether RSEI-estimated toxicity-weighted concentrations were associated with 1) odds of prevalent dementia and 2) incident dementia risk by subtype.ResultsAfter adjusting for individual and census-tract level covariates, a doubling in toxicity-weighted concentrations was associated with 9 % higher odds of prevalent dementia (OR = 1.09, 95 % CI: 1.00, 1.19). In discrete-time survival models, each doubling in toxicity-weighted concentrations was associated with a 16 % greater hazard of vascular dementia (HR = 1.16, 95 % CI: 1.01, 1.34) but was not significantly associated with all-cause, Alzheimer's disease, or mixed dementia (p's > 0.05).DiscussionLiving in regions with higher toxicity-weighted concentrations was associated with higher odds of prevalent dementia and a higher risk of incident vascular dementia in this large, community-based cohort of older adults. These findings support the need for additional studies to examine whether toxic chemical emissions from industrial and federal facilities may be a modifiable target for dementia prevention.

Background and Objectives:Neighborhood walkability can influence walking behaviors in older adults. However, its associations of walkability with walking may differ by demographic, socioeconomic, health, social, and residential characteristics due to factors such as increased vulnerability to environmental factors or increased resilience. Research Design and Methods:In a sample of older adults (n = 493, median age = 82 [range 78-89], 56% female, 31% Black), a walkability index was derived from audits of Google Street View images of participants' immediate neighborhoods. Walking was self-reported in the past week. Effect modifiers by demographic (age, race, gender, marital status), socioeconomic (education, income), health (gait speed, falls, knee pain, depressive symptoms, cognitive status, perceived energy), social (driving status, social engagement), and residential/neighborhood (residence type, neighborhood socioeconomic status [SES], population density) characteristics were assessed by interaction terms in logistic regression models, adjusted for gender, race, gait speed, prior falls, high depressive symptoms, currently driving, and cognitive status. When effect modification was suggested (p for interaction <.1), adjusted analyses of walkability with walking stratified on the effect modifier were conducted. Results:In this sample, 59% walked in the past week and greater walkability was associated with greater odds of walking (odds ratio [OR] = 1.16, 95% confidence interval [CI]: 1.01-1.34). This association (p for interaction range 0.002-0.07) was present for those who were not currently married (OR = 1.35, 95% CI: 1.17-1.56), who reported knee pain (OR = 1.40, 95% CI: 1.14-1.72) or high depressive symptoms (OR = 1.30, 95% CI: 1.06-1.60), or who had declining cognitive function (OR = 1.30, 95% CI: 1.09-1.55). Discussion and Implications:High walkability may influence physical activity, particularly for those with vulnerabilities related to social, pain, and brain health characteristics. These results should inform neighborhood planning and targeted interventions for vulnerable older adults.

Abstract Physical capacity (e.g., objective fitness, perceived fatigability) contributes independently to life-space mobility, the extent and independence of travel within the community. This relationship may differ by neighborhood context, where higher physical capacity may be especially necessary to overcome environmental barriers to mobility. We examined baseline associations between physical capacity and life-space mobility in community-dwelling older adults, and whether these associations were moderated by perceived neighborhood factors. Participants were from the Study of Muscle, Mobility and Aging (SOMMA; N=775, Mean±Standard Deviation age=76.1±4.9). Life-space mobility was self-reported using the Life-Space Assessment (higher=greater life-space, 83.6±19.3). Physical capacity measures included maximal treadmill cardiorespiratory fitness (VO2peak, 20.3±4.8 mL/min/kg) and perceived physical fatigability (Pittsburgh Fatigability Scale (PFS) Physical score, higher=more fatigability, 15.4±8.5). Self-reported neighborhood physical disorder (e.g., trash/vandalism) and social cohesion (e.g., neighborhood trust) scores were stratified into tertiles. Linear regressions estimated associations adjusted for demographic, health, and socioeconomic confounders. Each 1-SD higher VO2peak was associated with 2.5-point higher (95% CI: 0.84,4.2) life-space score, with associations significantly greater for the highest physical disorder tertile (b=3.8, 95% CI: 1.5,6.2, p-interaction=.018) and lowest social cohesion tertile (b=5.7, 95% CI: 2.9,8.6, p-interaction=.046). Each 1-SD higher PFS Physical score was associated with 3.2-point lower (95% CI: -4.6,-1.7) life-space score, with no differences by neighborhood measures (p-interactions>.15). Unlike perceived physical fatigability, the impact of objective fitness on life-space mobility may be greatest for those living in more disordered and less socially integrated neighborhoods. Findings reinforce the importance of considering individual-level contributors to life-space mobility within the environmental context (i.e., person-environment fit).

Background: Neighborhood walkability may encourage greater out-of-home travel (ie, community mobility) to support independent functioning in later life. We examined associations between a novel walkability audit index and Global Positioning System (GPS)-derived community mobility in community-dwelling older adults. We compared associations with the validated Environmental Protection Agency (EPA) National Walkability Index and further examined moderation by clinical walking speed. Methods: Participants were 146 older adults (Mean = 77.0 +/- 6.5 years, 68% women) at baseline of a randomized trial to improve walking speed. A walkability index (range: 0-5; eg, land-use mix, crosswalks, and so on) was created using Google Street View audits within 1/8-mile of the home. Participants carried a GPS device for 5-7 days to derive objective measures of community mobility (eg, time spent out of home, accumulated distance from home). Results: Each 1 SD (similar to 1.3-point) greater walkability audit score was associated with a median 2.16% more time spent out of home (95% confidence interval [95% CI]: 0.30-4.03, p = .023), adjusting for individual demographics/health and neighborhood socioeconomic status. For slower walkers (4-m walking speed <1 m/s), each 1 SD greater audit score was also associated with a median 4.54 km greater accumulated distance from home (95% CI: 0.01-9.07, p (interaction) = .034). No significant associations were found for the EPA walkability index. Conclusions: Walkability immediately outside the home was related to greater community mobility, especially for older adults with slower walking speeds. Results emphasize the need to consider the joint influence of local environment and individual functioning when addressing community mobility in older populations.

Abstract Air pollution is a modifiable risk factor for dementia. Yet, studies on specific forms of air pollution (e.g., toxic chemical emissions from industrial facilities) and dementia risk are underexplored. We examined associations between toxicity-weighted concentrations of industrial pollution and dementia outcomes among a large, multi-site cohort of older adults. Participants (n=2,770) were ≥ 65 years old (M=75.3, SD=5.1 years) from the Cardiovascular Health Cognition Study. Toxicity-weighted concentrations were estimated using the Risk Screening Environmental Indicator (RSEI) model which incorporates total reported chemical emissions with toxicity, fate, and transport models. Estimates were aggregated to participants’ baseline census tract, averaged across 1988-1992, and log10-transformed. Dementia status was clinically adjudicated in 1998-1999 (M=5.2 person-periods) by subtype (all-cause, Alzheimer’s, vascular, mixed). We assessed whether RSEI-estimated toxicity-weighted concentrations were associated with: 1) odds of prevalent dementia and 2) incident dementia risk by subtype. After adjusting for individual and neighborhood-level covariates, a 1-unit increase in log10-toxicity was associated with a 34% increase in the odds of prevalent dementia (OR=1.34, 95% CI: 1.01, 1.78). In discrete-time survival models, each 1-unit increase in log10-toxicity was associated with a 65% increased hazard of vascular dementia (HR=1.65, 95% CI: 1.04, 2.61) but was not significantly associated with all-cause, Alzheimer’s disease, or mixed dementia. Living in regions with higher toxic air emissions was associated with greater odds of prevalent dementia and a heightened risk of incident vascular dementia. Results suggest that the RSEI model may be a novel screening tool for examining associations between toxic chemical releases and dementia risk.

Time awake with advancing age is increasingly spent sedentary and has several negative health consequences. We examined associations between the frequency of daily sedentary and active bouts with all‐cause mortality.

Abstract The COVID-19 pandemic has renewed focus on social connections as fundamental contributors to health across the lifespan. Social connections have been studied in numerous ways (e.g., social network size, daily social interactions, engagement in social activities) and may facilitate health via multiple, dynamic biopsychosocial mechanisms. In line with this year’s theme, we review novel insights from early-career scholars into how “building bridges” with others throughout life may promote mental and cognitive health in later life. Further, we emphasize how bridging disciplines (e.g., social and neurocognitive sciences) is vital to understanding how social environments may “get under the skin” to impact health. Presentations will span multiple social-ecological levels (community, institutional, interpersonal). Beginning at the community/institutional level, Dr. Moored will discuss how the quantity of neighborhood social destinations contributes to GPS measures of community mobility in older adults. Dr. Britt will then describe how religious participation, a specific social institutional activity, is associated with an inflammatory biomarker predictive of cognitive impairments. The remaining talks will then report on daily social experiences. Dr. Ng will highlight links between daily support exchanges and life satisfaction in older adults and how these relationships differ by marital status. Extending to the caregiving context, Dr. Puga will present on how role captivity and daily changes in social isolation contribute to mood symptoms in family caregivers of individuals living with dementia. Our Discussant, Dr. Cudjoe, will provide a critical review in the context of new directions for research on social connections and environments.

Abstract Gait automaticity may decline with age-related impairments in the brain. As subcortical structures supporting gait automaticity decline, the prefrontal cortex (PFC) may provide compensatory function, allowing for maintenance of mobility but with loss of efficiency. Loss of efficiency may reduce ability to navigate complex community environments and restrict community mobility. We assessed the relation between PFC activation during walking in the laboratory with self-reported and objectively measured community mobility in participants aged 65+ (n=42, mean age=76, 60% female) from a randomized trial of a physical activity intervention to improve walking speed. PFC activation was measured by functional near-infrared spectroscopy as change from quiet standing to usual pace walking. Community mobility was measured objectively by 7-day global positioning system recordings of spatial (standard deviation ellipse area (SDEa), maximum distance from home) and temporal (percent time out of home (pTOH)) characteristics. Additionally, step count was recorded from 7-day actigraphy and the Life-Space Assessment (LSA) assessed self-reported mobility. Among participants with complete data at baseline (n=27), higher PFC activation during walking was associated with smaller SDEa (beta=-0.93 (-1.72, -0.15)), less pTOH (beta=-0.45 (-0.78, -0.12)), and lower step count (beta=-346 (-575, -118)) which persisted after adjusting for age, gender, education, or gait speed. PFC activation was not associated with maximum distance or LSA. There were no significant associations at the post-intervention visits (n=39). Greater PFC activation, likely indicating reduced gait automaticity, is related to lower spatial extent, duration, and intensity of community mobility. This association may be mitigated by participation in physical activity interventions.

The objective of this study was to understand older adults’ perceptions of the connections between an exergame intervention, “I Am Dolphin,” and their subjective well-being. Researchers conducted three focus groups with 14 older adults who participated in the exergame feasibility study. The semi-structured focus groups were transcribed, coded, and analysed using deductive and inductive techniques. Three themes were constructed related to playing the exergame and participants’ subjective well-being: 1) elevated mood (through scheduled activity, immersion, and socialization), 2) feelings of achievement (especially following frustration and competition), and 3) perceived cognitive or physical changes. These findings will help researchers better understand how exergames may relate to the well-being of older adults. Future investigators could use these findings to create and implement new exergame interventions.