Associations between toxicity-weighted concentrations and dementia risk: Results from the Cardiovascular Health Cognition Study.

BACKGROUND: Air 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. METHODS: Participants (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. RESULTS: After 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). DISCUSSION: Living 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.

Neighborhood Walkability Is Associated With Global Positioning System-Derived Community Mobility of Older Adults.

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 ±â€…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 (~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.

Identification of complier and noncomplier average causal effects in the presence of latent missing-at-random (LMAR) outcomes: a unifying view and choices of assumptions.

The study of treatment effects is often complicated by noncompliance and missing data. In the one-sided noncompliance setting where of interest are the complier and noncomplier average causal effects, we address outcome missingness of the latent missing at random type (LMAR, also known as latent ignorability). That is, conditional on covariates and treatment assigned, the missingness may depend on compliance type. Within the instrumental variable (IV) approach to noncompliance, methods have been proposed for handling LMAR outcome that additionally invoke an exclusion restriction-type assumption on missingness, but no solution has been proposed for when a non-IV approach is used. This article focuses on effect identification in the presence of LMAR outcomes, with a view to flexibly accommodate different principal identification approaches. We show that under treatment assignment ignorability and LMAR only, effect nonidentifiability boils down to a set of two connected mixture equations involving unidentified stratum-specific response probabilities and outcome means. This clarifies that (except for a special case) effect identification generally requires two additional assumptions: a specific missingness mechanism assumption and a principal identification assumption. This provides a template for identifying effects based on separate choices of these assumptions. We consider a range of specific missingness assumptions, including those that have appeared in the literature and some new ones. Incidentally, we find an issue in the existing assumptions, and propose a modification of the assumptions to avoid the issue. Results under different assumptions are illustrated using data from the Baltimore Experience Corps Trial.

Association of Postoperative Delirium With Incident Dementia and Graft Outcomes Among Kidney Transplant Recipients.

BACKGROUND: Kidney transplant (KT) recipients have numerous risk factors for delirium, including those shared with the general surgical population (eg, age and major surgery) and transplant-specific factors (eg, neurotoxic immunosuppression medications). Evidence has linked delirium to long-term dementia risk in older adults undergoing major surgery. We sought to characterize dementia risk associated with post-KT delirium. METHODS: Using the United States Renal Data System datasets, we identified 35 800 adult first-time KT recipients ≥55 y. We evaluated risk factors for delirium using logistic regression. We evaluated the association between delirium and incident dementia (overall and by subtype: Alzheimer's, vascular, and other/mixed-type), graft loss, and death using Fine and Gray's subhazards models and Cox regression. RESULTS: During the KT hospitalization, 0.9% of recipients were diagnosed with delirium. Delirium risk factors included age (OR = 1.40, 95% CI, 1.28-1.52) and diabetes (OR = 1.38, 95% CI, 1.10-1.73). Delirium was associated with higher risk of death-censored graft loss (aHR = 1.52, 95% CI, 1.12-2.05) and all-cause mortality (aHR = 1.53, 95% CI, 1.25-1.89) at 5 y post-KT. Delirium was also associated with higher risk of dementia (adjusted subhazard ratio [aSHR] = 4.59, 95% CI, 3.48-6.06), particularly vascular dementia (aSHR = 2.51, 95% CI, 1.01-6.25) and other/mixed-type dementia (aSHR = 5.58, 95% CI, 4.24-7.62) subtypes. The risk of all-type dementia associated with delirium was higher for younger recipients aged between 55 and 64 y ( Pinteraction = 0.01). CONCLUSIONS: Delirium is a strong risk factor for subsequent diagnosis of dementia among KT recipients, particularly those aged between 55 and 64 y at the time of transplant. Patients experiencing posttransplant delirium might benefit from early interventions to enhance cognitive health and surveillance for cognitive impairment to enable early referral for dementia care.

Association of Gait Quality With Daily-Life Mobility: An Actigraphy and Global Positioning System Based Analysis in Older Adults.

OBJECTIVE: Walking is a key component of daily-life mobility. We examined associations between laboratory-measured gait quality and daily-life mobility through Actigraphy and Global Positioning System (GPS). We also assessed the relationship between two modalities of daily-life mobility i.e., Actigraphy and GPS. METHODS: In community-dwelling older adults (N = 121, age = 77±5 years, 70% female, 90% white), we obtained gait quality from a 4-m instrumented walkway (gait speed, walk-ratio, variability) and accelerometry during 6-Minute Walk (adaptability, similarity, smoothness, power, and regularity). Physical activity measures of step-count and intensity were captured from an Actigraph. Time out-of-home, vehicular time, activity-space, and circularity were quantified using GPS. Partial Spearman correlations between laboratory gait quality and daily-life mobility were calculated. Linear regression was used to model step-count as a function of gait quality. ANCOVA and Tukey analysis compared GPS measures across activity groups [high, medium, low] based on step-count. Age, BMI, and sex were used as covariates. RESULTS: Greater gait speed, adaptability, smoothness, power, and lower regularity were associated with higher step-counts (0.20<|ρp| < 0.26, p < .05). Age(ß = -0.37), BMI(ß = -0.30), speed(ß = 0.14), adaptability(ß = 0.20), and power(ß = 0.18), explained 41.2% variance in step-count. Gait characteristics were not related to GPS measures. Participants with high (>4800 steps) compared to low activity (steps<3100) spent more time out-of-home (23 vs 15%), more vehicular travel (66 vs 38 minutes), and larger activity-space (5.18 vs 1.88 km2), all p < .05. CONCLUSIONS: Gait quality beyond speed contributes to physical activity. Physical activity and GPS-derived measures capture distinct aspects of daily-life mobility. Wearable-derived measures should be considered in gait and mobility-related interventions.

Global Positioning System Indicators of Community Mobility and Future Health Outcomes Among Older Adults.

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 ±â€…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 ±â€…standard deviation of the median SDE area was 4.4 ±â€…8.5 km2, median SDE compactness 0.7 ±â€…0.2, median percentage TOH 14.4 ±â€…12.0%, and median maximum distance from home was 38 ±â€…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.

CogDrisk, ANU-ADRI, CAIDE, and LIBRA Risk Scores for Estimating Dementia Risk.

Importance: While the Australian National University-Alzheimer Disease Risk Index (ANU-ADRI), Cardiovascular Risk Factors, Aging, and Dementia (CAIDE), and Lifestyle for Brain Health (LIBRA) dementia risk tools have been widely used, a large body of new evidence has emerged since their publication. Recently, Cognitive Health and Dementia Risk Index (CogDrisk) and CogDrisk for Alzheimer disease (CogDrisk-AD) risk tools have been developed for the assessment of dementia and AD risk, respectively, using contemporary evidence; comparison of the relative performance of these risk tools is limited. Objective: To evaluate the performance of CogDrisk, ANU-ADRI, CAIDE, LIBRA, and modified LIBRA (LIBRA with age and sex estimates from ANU-ADRI) in estimating dementia and AD risks (with CogDrisk-AD and ANU-ADRI). Design, Setting, and Participants: This population-based cohort study obtained data from the Rush Memory and Aging Project (MAP), the Cardiovascular Health Study Cognition Study (CHS-CS), and the Health and Retirement Study-Aging, Demographics and Memory Study (HRS-ADAMS). Participants who were free of dementia at baseline were included. The factors were component variables in the risk tools that included self-reported baseline demographics, medical risk factors, and lifestyle habits. The study was conducted between November 2021 and March 2023, and statistical analysis was performed from January to June 2023. Main outcomes and measures: Risk scores were calculated based on available factors in each of these cohorts. Area under the receiver operating characteristic curve (AUC) was calculated to measure the performance of each risk score. Multiple imputation was used to assess whether missing data may have affected estimates for dementia risk. Results: Among the 6107 participants in 3 validation cohorts included for this study, 2184 participants without dementia at baseline were available from MAP (mean [SD] age, 80.0 [7.6] years; 1606 [73.5%] female), 548 participants without dementia at baseline were available from HRS-ADAMS (mean [SD] age, 79.5 [6.3] years; 288 [52.5%] female), and 3375 participants without dementia at baseline were available from CHS-CS (mean [SD] age, 74.8 [4.9] years; 1994 [59.1%] female). In all 3 cohorts, a similar AUC for dementia was obtained using CogDrisk, ANU-ADRI, and modified LIBRA (MAP cohort: CogDrisk AUC, 0.65 [95% CI, 0.61-0.69]; ANU-ADRI AUC, 0.65 [95% CI, 0.61-0.69]; modified LIBRA AUC, 0.65 [95% CI, 0.61-0.69]; HRS-ADAMS cohort: CogDrisk AUC, 0.75 [95% CI, 0.71-0.79]; ANU-ADRI AUC, 0.74 [95% CI, 0.70-0.78]; modified LIBRA AUC, 0.75 [95% CI, 0.71-0.79]; CHS-CS cohort: CogDrisk AUC, 0.70 [95% CI, 0.67-0.72]; ANU-ADRI AUC, 0.69 [95% CI, 0.66-0.72]; modified LIBRA AUC, 0.70 [95% CI, 0.68-0.73]). The CAIDE and LIBRA also provided similar but lower AUCs than the 3 aforementioned tools (eg, MAP cohort: CAIDE AUC, 0.50 [95% CI, 0.46-0.54]; LIBRA AUC, 0.53 [95% CI, 0.48-0.57]). The performance of CogDrisk-AD and ANU-ADRI in estimating AD risks was also similar. Conclusions and relevance: CogDrisk and CogDrisk-AD performed similarly to ANU-ADRI in estimating dementia and AD risks. These results suggest that CogDrisk and CogDrisk-AD, with a greater range of modifiable risk factors compared with other risk tools in this study, may be more informative for risk reduction.

Effects of a Physical Therapist Intervention on GPS Indicators of Community Mobility in Older Adults: A Secondary Analysis of a Randomized Controlled Trial.

OBJECTIVE: The authors compared the effects of a standard strength and endurance intervention with a standard plus timing and coordination training intervention on community mobility measured using global positioning systems (GPS) among community-dwelling older adults in this secondary analysis of a randomized controlled trial. METHODS: Participants were randomized to a standard or a standard plus timing and coordination training program. Community mobility was measured using the Life Space Assessment (LSA) and GPS indicators of community mobility at baseline, as well as at 12 (immediately after the intervention), 24, and 36 weeks. Linear mixed models were used for analysis. RESULTS: There were 166 participants with GPS data at baseline, including 81 in the standard plus group and 85 in the standard group. The groups did not differ in participant characteristics or GPS measures at baseline. There were no significant within-group changes in GPS indicators of community mobility or LSA score over time, nor between-group differences of the same. CONCLUSION: There were no significant changes in community mobility with either intervention or between-intervention differences. These findings suggest that interventions targeting physical function alone may not be sufficient to improve community mobility or participation in older adults. Future research should focus on the development of multifaceted interventions targeted to improve real-world participation. IMPACT: The studied interventions did not significantly change community mobility measured using GPS-derived community mobility measures or self-report measures in older adults, suggesting that more comprehensive interventions may be needed to target improvements in community mobility.

Hearing Impairment and Allostatic Load in Older Adults.

Importance: Allostatic load, the cumulative strain that results from the chronic stress response, is associated with poor health outcomes. Increased cognitive load and impaired communication associated with hearing loss could potentially be associated with higher allostatic load, but few studies to date have quantified this association. Objective: To investigate if audiometric hearing loss is associated with allostatic load and evaluate if the association varies by demographic factors. Design, Setting, Participants: This cross-sectional survey used nationally representative data from the National Health and Nutrition Examination Survey. Audiometric testing was conducted from 2003 to 2004 (ages 20-69 years) and 2009 to 2010 (70 years or older). The study was restricted to participants aged 50 years or older, and the analysis was stratified based on cycle. The data were analyzed between October 2021 and October 2022. Exposure: A 4-frequency (0.5-4.0 kHz) pure tone average was calculated in the better-hearing ear and modeled continuously and categorically (<25 dB hearing level [dB HL], no hearing loss; 26-40 dB HL, mild hearing loss; ≥41 dB HL, moderate or greater hearing loss). Main Outcome and Measures: Allostatic load score (ALS) was defined using laboratory measurements of 8 biomarkers (systolic/diastolic blood pressure, body mass index [calculated as weight in kilograms divided by height in meters squared], and total serum and high-density lipoprotein cholesterol, glycohemoglobin, albumin, and C-reactive protein levels). Each biomarker was assigned a point if it was in the highest risk quartile based on statistical distribution and then summed to yield the ALS (range, 0-8). Linear regression models adjusted for demographic and clinical covariates. Sensitivity analysis included using clinical cut points for ALS and subgroup stratification. Results: In 1412 participants (mean [SD] age, 59.7 [5.9] years; 293 women [51.9%]; 130 [23.0%] Hispanic, 89 [15.8%] non-Hispanic Black, and 318 [55.3%] non-Hispanic White individuals), a modest association was suggested between hearing loss and ALS (ages 50-69 years: ß = 0.19 [95% CI, 0.02-0.36] per 10 dB HL; 70 years or older: ß = 0.10 [95% CI, 0.02-0.18] per 10 dB HL) among non-hearing aid users. Results were not clearly reflected in the sensitivity analysis with clinical cut points for ALS or modeling hearing loss categorically. Sex-based stratifications identified a stronger association among male individuals (men 70 years or older: ß = 0.22 [95% CI, 0.12-0.32] per 10 dB HL; women: ß = 0.08 [95% CI, -0.04 to 0.20] per 10 dB HL). Conclusion and Relevance: The study findings did not clearly support an association between hearing loss and ALS. While hearing loss has been shown to be associated with increased risk for numerous health comorbidities, its association with the chronic stress response and allostasis may be less than that of other health conditions.

Examining the Causal Mediating Role of Cardiovascular Disease on the Effect of Subclinical Cardiovascular Disease on Cognitive Impairment via Separable Effects.

BACKGROUND: An important epidemiological question is understanding how vascular risk factors contribute to cognitive impairment. Using data from the Cardiovascular Health Cognition Study, we investigated how subclinical cardiovascular disease (sCVD) relates to cognitive impairment risk and the extent to which the hypothesized risk is mediated by the incidence of clinically manifested cardiovascular disease (CVD), both overall and within apolipoprotein E-4 (APOE-4) subgroups. METHODS: We adopted a novel "separable effects" causal mediation framework that assumes that sCVD has separably intervenable atherosclerosis-related components. We then ran several mediation models, adjusting for key covariates. RESULTS: We found that sCVD increased overall risk of cognitive impairment (risk ratio [RR] = 1.21, 95% confidence interval [CI]: 1.03, 1.44); however, there was little or no mediation by incident clinically manifested CVD (indirect effect RR = 1.02, 95% CI: 1.00, 1.03). We also found attenuated effects among APOE-4 carriers (total effect RR = 1.09, 95% CI: 0.81, 1.47; indirect effect RR = 0.99, 95% CI: 0.96, 1.01) and stronger findings among noncarriers (total effect RR = 1.29, 95% CI: 1.05, 1.60; indirect effect RR = 1.02, 95% CI: 1.00, 1.05). In secondary analyses restricting cognitive impairment to only incident dementia cases, we found similar effect patterns. CONCLUSIONS: We found that the effect of sCVD on cognitive impairment does not seem to be mediated by CVD, both overall and within APOE-4 subgroups. Our results were critically assessed via sensitivity analyses, and they were found to be robust. Future work is needed to fully understand the relationship between sCVD, CVD, and cognitive impairment.

OLDER ADULTS' SUBJECTIVE WELL-BEING EXPERIENCING THE EXERGAME "I AM DOLPHIN".

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.

Body Mass Index and Cognition: Associations Across Mid- to Late Life and Gender Differences.

BACKGROUND: Higher mid-life body mass index (BMI) is associated with lower late-life cognition. Associations between later-life BMI and cognition are less consistent; evidence suggests reverse causation may play a role. We aimed to characterize associations between BMI and cognition across a wide age range during mid- to late life (55-85 years) and examine whether associations vary by gender. METHODS: We used data from the Health and Retirement Study (HRS) (N = 39,153) to examine the association between BMI and 3 cognitive outcomes: cognitive level, cognitive decline, and cognitive impairment. We used a series of linear regression, mixed effects regression, and logistic regression models, adjusting for potential confounders. RESULTS: Higher BMI before age 65 (midlife) was associated with lower cognitive performance, faster rates of cognitive decline, and higher odds of cognitive impairment in late life. Averaging across analyses assessing associations between BMI measured before age 60 and late-life cognition, a 5-unit higher level of BMI was associated with a 0.26 point lower cognitive score. Beyond age 65, associations flipped, and higher BMI was associated with better late-life cognitive outcomes. Associations in both directions were stronger in women. Excluding those with BMI loss attenuated findings among women in older ages, supporting the reverse causation hypothesis. CONCLUSIONS: In this sample, age 65 represented a critical turning point between mid- and late life for the association between BMI and cognition, which has important implications for recruitment strategies for studies focused on risk factors for late-life cognitive outcomes. Evidence of gender differences raises the need to further investigate plausible mechanisms.

Neighborhood greenspace and cognition: The cardiovascular health study.

OBJECTIVES: We examined whether greenspace measures (overall percent greenspace and forest, and number of greenspace types) were associated with clinically adjudicated dementia status. METHODS: In a sample of non-demented older adults (n = 2141, average age = 75.3 years) from the Cardiovascular Health and Cognition Study, Cox proportional hazard and logistic regression analyses were used to estimate associations of baseline greenspace with risks of incident dementia and MCI, respectively, while adjusting for demographics, co-morbidities, and other neighborhood factors. We derived quartiles of percent greenness (greenspace), forest (percent tree canopy cover), and tertiles of greenspace diversity (number of greenspace types) for 5-km radial buffers around participant's residences at study entry (1989-1990) from the 1992 National Land Cover Dataset. Dementia status and mild cognitive impairment (MCI) over 10 years was clinically adjudicated. RESULTS: We observed no significant association between overall percent greenspace and risk of mild cognitive impairment or dementia and mostly null results for forest and greenspace diversity. Forest greenspace was associated with lower odds of MCI (OR quartile 4 versus 1: 0.54, 95% CI: 0.29-0.98) and greenspace diversity was associated with lower hazard of incident dementia (HR tertile 2 versus 1: 0.70, 95% CI = 0.50-0.99). DISCUSSION: We found divergent results for different types of greenspace and mild cognitive impairment or dementia. Improved greenspace type and diversity measurement could better characterize the association between greenspace and cognition.

Older Adults and Three-Dimensional Exergaming: Motivators and Barriers to Participation and Retention.

Background: Cognitive and physical activity are important for daily functioning. However, limited research exists on the motivators and barriers associated with older adults participating and adhering to exergame studies that promote physical and cognitive activity. Our objective was to examine older adults' motivators and barriers to joining and completing a three-dimensional exergame study. Methods: Fourteen older adults who participated in the exergame study contributed to one of three focus group discussions. Inductive and deductive methods were used to analyze the qualitative data. Results: Motivators for joining were generativity, peer referrals, self-improvement, and curiosity. Accomplishment, immersion, and exercise were motivators for retention. Participants also cited the structured schedule and adaptive difficulty features as motivators for retention. Barriers to participation included frustration due to lack of level advancement and fatigue/pain during gameplay. Some (n = 3) reported camera tracking issues as a barrier. Unanticipated gender-based trends arose when examining perceptions of the study team's role and motivators for retention. Conclusion: These findings will inform future research strategies for participant recruitment, enrollment, and retention, in addition to providing insights into the design of motivating, enjoyable, and sustainable exergames for older adults.

The relationship between older adults' technology use, in-person engagement, and pandemic-related mental health.

OBJECTIVE: The objectives of this study are to 1) describe changes in in-person communication/activity and changes in older adult technology use during the COVID-19 pandemic and 2) examine whether less in-person communication/activity mediates the relationship between pandemic-related mental health and technology use. METHOD: Linear regressions (stratified by age and financial strain) and structural equation modeling were employed using a nationally representative, cross-sectional survey of 3,188 older adults from the 2020 National Health and Aging Trends Study's COVID-19 Questionairre. RESULTS: Older adults engaged in more technology-based activity (b = 0.24; p<.001), more technology-based health care communication (b = 0.22; p<.001), and more technology-based food acquisition (b = 0.21; p<.001) during the COVID-19 pandemic, as compared to before the pandemic. Results indicate that adults <80 years old demonstrated greater increases in technology-based activity, technology-based health communication, and technology-based food acquisition, compared to adults ≥80 years old. Change in in-person communication significantly mediated the relationship between pandemic-related mental health and technology-based communication (standardized coefficient= -0.012; p=.005), and change in in-person activity significantly mediated the relationship between pandemic-related mental health and technology-based activity (standardized coefficient= -0.017; p=.020). CONCLUSIONS: This study suggests that older adults are utilizing technology more, and therefore should be considered in technology design and dissemination. Technology use could be an important positive response to help those with pandemic related worries stay safely engaged with friends and family. Technologies should be produced that are modifiable for older adults with disabilities and affordable for older adults with fixed incomes.

Exploring the Relationship Between Engagement in Enriching Early-Life Activities During Adolescence and Cognition in Later-Life: Results From the Health and Retirement Study.

The cognitive benefits associated with mid- to late-life engagement have been demonstrated in several studies. However, the link between engagement in enriching early-life activities (EELAs) during adolescence and later-life cognition has been relatively unexplored in major epidemiological studies. We examined the EELA-cognition relationship in a nationally representative sample of adults aged 50+. A subset of Health and Retirement Study respondents (n=3482) completed cognitive tests and returned a retrospective early-life activity inventory. Linear regression models analyzed the EELA-cognition relationship, and multiple imputation addressed missingness. Each additional EELA was associated with a 0.36 point higher cognitive score (95% CI: 0.24, 0.47). This relationship remained significant after adjusting for potential confounders (B=0.16; 95% CI: [0.06, 0.26]). EELA engagement was associated with better later-life cognitive performance. This study is understood to be the first to examine the EELA-cognition relationship using a large, nationally representative dataset. The findings highlight the importance of early-life engagement during an important developmental period (e.g., adolescence).

Peak Expiratory Flow Predicts Incident Dementia in a Representative Sample of U.S. Older Adults: The National Health and Aging Trends Study (NHATS).

BACKGROUND: Dementia is an increasingly important public health problem with various risk factors. Respiratory function, measured via peak expiratory flow (PEF), may be a modifiable dementia risk factor. METHODS: We investigated the association between PEF and incident dementia in 5 935 older adults from the National Health and Aging Trends Study (NHATS) from 2011 to 2014. Baseline PEF, expressed as a standardized residual (SR) percentile, was analyzed as a predictor of incident dementia using discrete-time proportional hazards models, while controlling for several health and sociodemographic covariates. RESULTS: After 14 332 person-years of follow-up, 9.0% (N = 536) had incident cases of dementia. Compared to the lowest PEF category (SR-percentile < 10%), the highest PEF category (SR-percentile ≥ 80%) had 49% lower risk of incident dementia (hazard ratio [HR] = 0.51; 95% confidence interval [CI; 0.37, 0.71]), and the second highest PEF category (SR-percentile 50%-80%) had 25% lower risk of incident dementia (HR = 0.75; 95% CI [0.56, 1.00]). A sensitivity analysis using multiple imputation to account for missing PEF measurements yielded similar associations with incident dementia. CONCLUSION: These associations suggest a dose-dependent relationship such that higher PEF categories were more protective against incident dementia. PEF may be considered as an easily administered, low-cost measure of respiratory function and a potentially modifiable dementia risk factor. Improving PEF may reduce dementia risk through vascular mechanisms, such as increased brain oxygenation. Future research should explore potential causal pathways between PEF and dementia.

Using GPS Technologies to Examine Community Mobility in Older Adults.

BACKGROUND: Objective measures of community mobility are advantageous for capturing movement outside the home. Compared with subjective, self-reported techniques, global positioning system (GPS) technologies leverage passive, real-time location data to reduce recall bias and increase measurement precision. We developed methods to quantify community mobility among community-dwelling older adults and assessed how GPS-derived indicators relate to clinical measures of physical and cognitive performance. METHODS: Participants (n = 149; M ± standard deviation [SD] = 77.1 ± 6.5 years) from the program to improve mobility in aging (PRIMA) study, a physical therapy intervention to improve walking ability, carried a GPS device for 7 days. Community mobility was characterized by assessing activity space, shape, duration, and distance. Associations between GPS-derived indicators and cognition and physical function were evaluated using Spearman correlations. RESULTS: In adjusted models, a larger activity space, greater duration (eg, time out-of-home), and greater distance traveled from home were correlated with better 6-Minute Walk Test performance (ρ = 0.17-0.23, p's < .05). A more circular activity shape was related to poorer performance on the Trail Making Test, Part A (ρ = 0.18, p < .05). More time out-of-home and a larger activity space were correlated with faster times on the Trail Making Test, Part B (ρ = -0.18 to -0.24, p's < .05). Community mobility measures were not associated with global cognition, skilled walking, or usual gait speed. CONCLUSION: GPS-derived community mobility indicators capture real-world activity among older adults and were correlated with clinical measures of executive function and walking endurance. These findings will guide the design of future interventions to promote community mobility.

Assessment of hearing and vision impairment in cohort studies collecting cognitive data in older adults.

INTRODUCTION: There are no standard practices for considering sensory impairment in studies measuring cognitive function among older adults. Exclusion of participants with impairments may inaccurately estimate the prevalence of cognitive impairment and dementia. METHODS: We surveyed prospective cohort studies measuring cognitive function in older adults, determined the proportion that excluded participants based on sensory impairment and the proportion that assessed each type of sensory impairment, and described the methods of sensory assessment. RESULTS: Investigators/staff from 85 (of 192 cohorts) responded; 6 (7%) excluded participants with severe impairment; 80 (94%) measured hearing and/or vision impairment, while 5 (6%) measured neither. Thirty-two (38%) cohorts assessed hearing objectively and 45 (53%) assessed vision objectively. DISCUSSION: Findings indicate variation in methods used to assess sensory impairment, with potential implications for resource allocation. To ensure equitable inclusion of study participants, consensus is needed on best practices standardized protocols for assessment and accommodations of sensory impairment.

Risk of Dementia Differs Across Lifestyle Engagement Subgroups: A Latent Class and Time-to-Event Analysis in Community-Dwelling Older Adults.

OBJECTIVES: Better understanding of the lifestyle activities shared among older adult subgroups may inform further health behavioral interventions that can be deployed at the group or community level. We applied latent class analysis to characterize qualitatively distinct lifestyle engagement groups, examined their differential risk of incident dementia, and compared their predictive utility to traditional activity frequency and variety scores. METHOD: Participants were from the Ginkgo Evaluation of Memory Study (N = 3,068, mean age = 78.5). Lifestyle activities were measured at baseline using the Lifestyle Activity Questionnaire. All-cause dementia was screened every 6 months and cases were clinically adjudicated. Median follow-up was 6 years. Time to dementia was assessed using discrete-time proportional hazards models, adjusted for demographic and health covariates. RESULTS: Latent classes provided slightly poorer case discrimination than the frequency scores but identified distinct qualitative subgroups. In the 4-class model, the Variety (22%) and Intellectual (18%) lifestyle groups had high engagement in intellectual activities, whereas the Variety and Social groups (32%) had high engagement in formal social activities. Compared to the Least Active group (28%), the Variety (hazard ratio [HR] = 0.67, 95% confidence interval [CI]: 0.48, 0.93) and Intellectual (HR = 0.65, 95% CI: 0.45, 0.93) groups had significantly lower risk of incident dementia, but only among those without prevalent mild cognitive impairment. DISCUSSION: Older adults highly engaged in intellectual activities, but not necessarily social activities, had the lowest risk of incident dementia. Activity frequency scores provided only slightly better case discrimination than activity variety scores and latent classes. Latent classes of older adults differed by their amount and types of activities, which may inform intervention design.