The association of motoric cognitive risk with incident dementia and neuroimaging characteristics: The Atherosclerosis Risk in Communities Study

INTRODUCTION

Motoric cognitive risk (MCR), a clinical syndrome characterized by slow gait speed and subjective cognitive complaints, has been associated with dementia risk. The neuropathological features underlying MCR remain poorly understood.

METHODS

The Atherosclerosis Risk in Communities (ARIC) community-based cohort study classified participants using standardized criteria as MCR+/- and mild cognitive impairment (MCI)+/- at study baseline (2011-2013). We examined the 5-year dementia risk and baseline brain structural/molecular abnormalities associated with MCR+ and MCI+ status.

RESULTS

Of 5023 nondemented participants included, 204 were MCR+ and 1030 were MCI+. Both MCR+ and MCI+ participants demonstrated increased dementia risk. The pattern of structural brain abnormalities associated with MCR+ differed from that of MCI+. Whereas MCI+ was associated with comparatively smaller volumes in brain regions vulnerable to Alzheimer's disease pathology, MCR+ status was associated with smaller volumes in frontoparietal regions and greater white matter abnormalities.

DISCUSSION

MCR may represent a predementia syndrome characterized by prominent white matter abnormalities and frontoparietal atrophy.

Endurance and gait speed relationships with mild cognitive impairment and dementia

INTRODUCTION

Slower mobility is associated with mild cognitive impairment (MCI) and dementia. We examined the interaction of endurance with gait speed on prevalent MCI and dementia.

METHODS

Cross-sectional multinomial regression in the ARIC cohort (n = 2844 participants; 71 to 94 years; 44% men; 18% Black persons) with cognitive status (normal/MCI/dementia), 4 m gait speed, and endurance (2 minute walk [2MW]).

RESULTS

Faster gait speed (up to but not above 1 m/s) and better 2MW were separately associated with lower dementia risk. Good performance in both (2MW = 200 m, gait speed = 1.2 m/s) was associated with 99% lower dementia (Relative Prevalence Ratio [RPR] = 0.01 [95% CI: 0.0 to 0.06]) and 73% lower MCI, RPR = 0.27 (0.15 to 0.48) compared to poor performance in both (2MW = 100 m, gait speed = 0.8 m/s). Models incorporating a gait speed-by-2MW interaction term outperformed gait speed-only models (P < .001).

DISCUSSION

Gait speed relationships with dementia diminish at faster gait speeds. Combining endurance with gait speed may yield more sensitive markers of MCI and dementia than gait speed alone.

Body mass index prediction rule for mid-upper arm circumference: the atherosclerosis risk in communities study

OBJECTIVES

Electronic health records (EHR) are a convenient data source for clinical trial recruitment and allow for inexpensive participant screening. However, EHR may lack pertinent screening variables. One strategy is to identify surrogate EHR variables which can predict the screening variable of interest. In this article, we use BMI to develop a prediction rule for arm circumference using data from the Atherosclerosis Risk in Communities (ARIC) Study. This work applies to EHR patient screening for clinical trials of hypertension.

METHODS

We included 11 585 participants aged 52-75 years with BMI and arm circumference measured at ARIC follow-up visit 4 (1996-1998). We selected the following arm circumference cutpoints based on the American Heart Association recommendations for blood pressure (BP) cuffs: small adult (≤26 cm), adult (≤34 cm) and large adult (≤44 cm). We calculated the sensitivity and specificity of BMI values for predicting arm circumference using receiver operating characteristic curves. We report the BMI threshold that maximized Youden's Index for each arm circumference upper limit of a BP cuff.

RESULTS

Participants' mean BMI and arm circumference were 28.8 ± 5.6 kg/m2 and 33.4 ± 4.3 cm, respectively. The BMI-arm circumference Pearson's correlation coefficient was 0.86. The BMI threshold for arm circumference≤26 cm was 23.0 kg/m2, arm circumference≤34 cm was 29.2 kg/m2 and arm circumference≤44 cm was 37.4 kg/m2. Only the BMI threshold for arm circumference≤34 cm varied significantly by sex.

CONCLUSIONS

BMI predicts arm circumference with high sensitivity and specificity and can be an accurate surrogate variable for arm circumference. These findings are useful for participant screening for hypertension trials. Providers can use this information to counsel patients on appropriate cuff size for BP self-monitoring.

The Neuroanatomic Correlates of Olfactory Identification Impairment in Healthy Older Adults and in Persons with Mild Cognitive Impairment

BACKGROUND

Olfactory identification (OI) impairment appears early in the course of Alzheimer's disease dementia (AD), prior to detectable cognitive impairment. However, the neuroanatomical correlates of impaired OI in cognitively normal older adults (CN) and persons with mild cognitive impairment (MCI) are not fully understood.

OBJECTIVE

We examined the neuroanatomic correlates of OI impairment in older adults from the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS).

METHODS

Our sample included 1,600 older adults without dementia who completed clinical assessment and structural brain imaging from 2011 to 2013. We characterized OI impairment using the 12-item Sniffin' Sticks odor identification test (score ≤6). We used voxel-based morphometry (VBM) and region of interest (ROI) analyses to examine the neuroanatomic correlates of impaired OI in CN and MCI, after adjusting for potential confounders. Analyses were also separately stratified by race and sex.

RESULTS

In CN, OI impairment was associated with smaller amygdala gray matter (GM) volume (p < 0.05). In MCI, OI impairment was associated with smaller GM volumes of the olfactory cortex, amygdala, entorhinal cortex, hippocampus, and insula (ps < 0.05). Differential associations were observed by sex in MCI; OI impairment was associated with lower insular GM volumes among men but not among women (p-interaction = 0.04). There were no meaningful interactions by race.

CONCLUSION

The brain regions associated with OI impairment in individuals without dementia are specifically those regions known to be the primary targets of AD pathogenic processes. These findings highlight the potential utility of olfactory assessment in the identification and stratification of older adults at risk for AD.

Obesity Duration, Severity, and Distribution Trajectories and Cardiovascular Disease Risk in the Atherosclerosis Risk in Communities Study

Background Research examining the role of obesity in cardiovascular disease (CVD) often fails to adequately consider heterogeneity in obesity severity, distribution, and duration. Methods and Results We here use multivariate latent class mixed models in the biracial Atherosclerosis Risk in Communities study (N=14 514; mean age=54 years; 55% female) to associate obesity subclasses (derived from body mass index, waist circumference, self-reported weight at age 25, tricep skinfold, and calf circumference across up to four triennial visits) with total mortality, incident CVD, and CVD risk factors. We identified four obesity subclasses, summarized by their body mass index and waist circumference slope as decline (4.1%), stable/slow decline (67.8%), moderate increase (24.6%), and rapid increase (3.6%) subclasses. Compared with participants in the stable/slow decline subclass, the decline subclass was associated with elevated mortality (hazard ratio [HR] 1.45, 95% CI 1.31, 1.60, P<0.0001) and with heart failure (HR 1.41, 95% CI 1.22, 1.63, P<0.0001), stroke (HR 1.53, 95% CI 1.22, 1.92, P=0.0002), and coronary heart disease (HR 1.36, 95% CI 1.14, 1.63, P=0.0008), adjusting for baseline body mass index and CVD risk factor profile. The moderate increase latent class was not associated with any significant differences in CVD risk as compared to the stable/slow decline latent class and was associated with a lower overall risk of mortality (HR 0.85, 95% CI 0.80, 0.90, P<0.0001), despite higher body mass index at baseline. The rapid increase latent class was associated with a higher risk of heart failure versus the stable/slow decline latent class (HR 1.34, 95% CI 1.10, 1.62, P=0.004). Conclusions Consideration of heterogeneity and longitudinal changes in obesity measures is needed in clinical care for a more precision-oriented view of CVD risk.

Loneliness and its predictors among older adults prior to and during the COVID-19 pandemic: cross-sectional and longitudinal survey findings from participants of the Atherosclerosis Risk in Communities (ARIC) Study cohort in the USA

OBJECTIVES

We aimed to ascertain the prevalence of perceived loneliness among older adults following the onset of the COVID-19 pandemic and to examine factors contributing to the perception of loneliness.

DESIGN

Cross-sectional and longitudinal data from the Atherosclerosis Risk in Communities (ARIC) Study cohort.

SETTING

The ARIC Study cohort, a prospective cohort that recruited (1987-1989) participants from four distinct communities in the USA.

PARTICIPANTS

2984 ARIC cohort members.

PRIMARY AND SECONDARY OUTCOMES

Perceived loneliness assessed using the University of California at Los Angeles (UCLA) UCLA three-item Loneliness Scale telephone interviews conducted May-October 2020 and prior to March 2020.

RESULTS

Of the total 5037 participants alive in 2020, 2984 (56.2%) responded to the UCLA three-item questionnaire (mean age 82.6 (SD 4.6) years, 586 (19.6%) black participants, 1081 (36.2%) men), of which 66 (2.2%) reported having had a COVID-19 infection during the observation period. The proportion of participants reporting feeling lonely was 56.3% (n=1680). Among participants with repeat measures of loneliness (n=516), 35.2% (n=182) reported feeling more lonely following pandemic onset. Self-rated health and emotional resilience were strongly associated with self-perceived loneliness. The burden of COVID-19 infections, concern about the pandemic and decreased self-reported physical activity were greater among black as compared with white participants and among those with an educational attainment of less than high school as compared with high school or more.

CONCLUSION

Findings from this study document the increase in perceived loneliness among older adults during the COVID-19 pandemic in the USA.

The Relationship of APOE ε4, Race, and Sex on the Age of Onset and Risk of Dementia

Objective: To investigate whether APOE ε4 genotype—an established risk factor for dementia—is associated with earlier age at diagnosis in addition to increased risk overall and in secondary analysis by race and sex.

Methods: We followed up 13,782 dementia-free individuals (n = 10,137 White, n = 3,645 Black, baseline age 60–66 years) in the Atherosclerosis Risk in Communities study for up to 30 years. Dementia was operationalized using standardized algorithms incorporating longitudinal cognitive change, proxy report, and hospital or death certificate dementia codes. We used a mixture of generalized gamma distributions to simultaneously estimate time to dementia, time to dementia-free death, and the proportion of individuals with dementia, by APOE ε4 status (≥1 vs. no alleles).

Results: Median age of dementia onset among APOE ε4 carriers was 81.7 (Blacks) and 83.3 years (Whites) compared with 82.6 (Blacks) and 85.7 years (Whites) in non-APOE ε4 carriers (p > 0.05 Blacks; p < 0.01 Whites). Age of dementia diagnosis did not differ by sex in ε4 carriers, but among non-carriers, average age was earlier in males than females regardless of race. APOE ε4 carriers had on average a higher proportion of diagnoses; results did not differ by race or sex.

Conclusions:APOE ε4 carrier status is associated with earlier age of dementia diagnosis with differences across race and sex. These findings clarify the causal role of APOE in dementia etiology, which could help better identify at-risk subgroups and may help facilitate better research trial recruitment and design.

Midlife Cardiovascular Health and Robust versus Frail Late-Life Status: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

We examined the relationship of midlife cardiovascular health (CVH) with late-life robustness among men and women and the impact of survivorship bias on sex-differences in robustness.

METHODS

Prospective analysis of 15,744 participants aged 45-64 (Visit 1 median age: 54 years, 55% female, 27% Black) in 1987-1989 from the population-based ARIC Study. CVH was operationalized according to the Life's Simple 7 (LS7) metric of health behaviors (smoking, weight, physical activity, diet, cholesterol, blood pressure, and glucose); each behavior was scored as ideal (2 points), intermediate (1 point), or poor (0 points) and summed. Late-life robust/pre-frail/frailty was defined at Visit 5 (2011-2013). Multinomial regression estimated relative prevalence ratios (RPR) of late-life robustness/pre-frailty/frailty/death across overall midlife LS7 score and components, for the full Visit 1 sample. Separate analyses considered Visit 5 survivors only.

RESULTS

For each one-unit greater midlife LS7 score, participants had a 37% higher relative prevalence of being robust versus frail (overall RPR=1.37, [95% CI: 1.30-1.44]; women=1.45 [1.36-1.54]; men=1.24 [1.13-1.36]). Among the full Visit 1 sample, women had a similar one-level higher robustness category prevalence (RPR=1.35 [95% CI: 1.32-1.39]) than men (RPR=1.31 [95% CI: 1.27-1.35]) for every one-unit higher midlife LS7 score. Among survivors, men were more likely to be robust than women at lower LS7 levels; differences were attenuated and not statistically different at higher midlife LS7 levels.

CONCLUSIONS

Midlife CVH is positively associated with robustness in late-life among men and women. Accounting for mortality in part explains documented sex-differences in robustness across all levels of LS7.

Heart health meets cognitive health: evidence on the role of blood pressure

The enormous societal and financial burden of Alzheimer's disease and related dementias requires the identification of risk factors and pathways to reduce dementia risk. Blood pressure (BP) management and control is one promising area, in which data have been inconclusive. Accumulating evidence over the past 5 years shows the effectiveness of BP management interventions among older individuals at risk, most notably from the SPRINT-MIND trial. These findings have been coupled with longitudinal observational data. However, to date, the results do not concur on the optimal timing and target of BP lowering, and further study in diverse populations is needed. Given the long preclinical phase of dementia and data supporting the importance of BP control earlier in the lifecourse, long-term interventional and observational studies in ethnically and racially diverse populations, with novel imaging and blood-based biomarkers of neurodegeneration and vascular cognitive impairment to understand the pathophysiology, are needed to advance the field.

Sex differences in in vivo tau neuropathology in a multiethnic sample of late middle-aged adults

It is unclear whether women have higher brain tau pathology. The objective of this study was to examine whether women have higher tau burden than men, and whether tau differences are independent of amyloid β (Aβ) burden. We conducted a cross-sectional analysis of a multiethnic sample of 252 nondemented late middle-aged (mean age: 64.1 years) adults with tau and amyloid Positron Emission Tomography (PET) data. Tau burden was measured as global standardized uptake value ratio (SUVR) in the middle/inferior temporal gyri and medial temporal cortex with 18F-MK-6240 PET. Aβ was measured as global SUVR with 18F-Florbetaben PET. Women had higher middle/inferior temporal gyri tau SUVR compared to men. However, no sex differences in the medial temporal cortex were observed. Women had higher brain Aβ SUVR compared to men. Continuous Aβ SUVR was positively correlated with medial temporal cortex and middle/inferior temporal gyri tau SUVR. However, there was no evidence of effect modification by Aβ SUVR on sex and tau. Compared with men, women in late middle age show higher tau burden, independent of Aβ.

Relationship Between Central Artery Stiffness, Brain Arterial Dilation, and White Matter Hyperintensities in Older Adults: The ARIC Study-Brief Report

[Figure: see text].

Association of Age-Related Hearing Impairment With Physical Functioning Among Community-Dwelling Older Adults in the US

IMPORTANCE

Hearing impairment, a common treatable condition, may contribute to poorer physical function with aging.

OBJECTIVE

To assess whether hearing impairment is associated with poorer physical function, reduced walking endurance, and faster decline in physical function.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, cross-sectional and longitudinal analyses were performed using data from the 2011 to 2019 period of the Atherosclerosis Risk in Communities study, a population-based study of community-dwelling adults at 4 sites in the US.

EXPOSURES

Hearing thresholds (per 10 dB) assessed with pure tone audiometry and categorized as normal hearing or mild, moderate, or severe hearing impairment.

MAIN OUTCOMES AND MEASURES

Physical function was assessed using the short physical performance battery (SPPB), with composite scores ranging from 0 to 12. A composite score of 6 or less and a score for each component (balance, gait speed, and chair stands) of 2 or less indicated poor performance. Walking endurance was assessed using a 2-minute fast-paced walk test. Tobit regression models adjusted for sociodemographic factors and medical history were used to calculate the mean differences in SPPB composite scores; logistic regression models, to estimate the odds ratios (ORs) of low SPPB composite and component scores; and linear mixed-effects models, to estimate the mean rate of change in SPPB composite scores over time.

RESULTS

Of the 2956 participants (mean [SD] age, 79 [4.6] years) who attended study visit 6 between 2016 and 2017, 1722 (58.3%) were women, and 2356 (79.7%) were White. As determined by pure tone audiometry, 973 (33%) participants had normal hearing, 1170 (40%) had mild hearing impairment, 692 (23%) had moderate hearing impairment, and 121 (4%) had severe hearing impairment. In the Tobit regression model, severe hearing impairment was associated with a lower mean SPPB score (β, -0.82; 95% CI, -0.34 to -1.30) compared with normal hearing. In fully adjusted logistic regression models, hearing impairment was associated with higher odds of low physical performance scores (severe impairment vs normal hearing: OR for composite physical performance, 2.51 [95% CI, 1.47-4.27]; OR for balance, 2.58 [95% CI, 1.62-4.12]; OR for gait speed, 2.11 [95% CI, 1.03-4.33]). Over time (2 to 3 visits; maximum, 8.9 years), participants with hearing impairment had faster declines in SPPB compared with those with normal hearing (moderate hearing impairment × time interaction, -0.34 [-0.52 to -0.16]). In adjusted models for walking endurance, participants with moderate or severe hearing impairment walked a mean distance of -2.81 m (95% CI, -5.45 to -0.17 m) and -5.31 m (95% CI, -10.20 to -0.36 m) than those with normal hearing, respectively, during the 2-minute walk test.

CONCLUSIONS AND RELEVANCE

In this cohort study, hearing impairment was associated with poorer performance, faster decline in physical function, and reduced walking endurance. The results of the longitudinal analysis suggest that hearing impairment may be associated with poorer physical function with aging. Whether management of hearing impairment could delay decline in physical function requires further investigation.

Prestroke Physical Activity and Adverse Health Outcomes After Stroke in the Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

The association of physical activity (PA) before stroke (prestroke PA) with long-term prognosis after stroke is still unclear. We examined the association of prestroke PA with adverse health outcomes in the ARIC study (Atherosclerosis Risk in Communities).

METHODS

We included 881 participants with incident stroke occurring between 1993 and 1995 (visit 3) and December 31, 2016. Follow-up continued until December 31, 2017 to allow for at least 1-year after incident stroke. Prestroke PA was assessed using a modified version of the Baecke questionnaire in 1987 to 1989 (visit 1) and 1993 to 1995 (visit 3), evaluating PA domains (work, leisure, and sports) and total PA. We used Cox proportional hazards models to quantify the association between tertiles of accumulated prestroke PA levels over the 6-year period between visits 1 and 3 and mortality, risk of cardiovascular disease, and recurrent stroke after incident stroke.

RESULTS

During a median follow-up of 3.1 years after incident stroke, 676 (77%) participants had adverse outcomes. Highest prestroke total PA was associated with decreased risks of all-cause mortality (hazard ratio, 0.78 [95% CI, 0.63-0.97]) compared with lowest tertile. In the analysis by domain-specific PA, highest levels of work PA were associated with lower risk for all-cause (hazard ratio, 0.77 [95% CI, 0.62-0.96]) and cardiovascular mortality (hazard ratio, 0.45 [95% CI, 0.29-0.70]), and highest levels of leisure PA were associated with lower all-cause mortality (hazard ratio, 0.72 [95% CI, 0.58-0.89]) compared with lowest tertile of PA. No significant associations for sports PA were observed.

CONCLUSIONS

Higher levels of total prestroke PA as well as work and leisure PA were associated with lower risk of mortality after incident stroke. Public health strategies to increase lifetime PA should be encouraged to decrease long-term mortality after stroke.

Abstract MP61: Greater Late-life Physical Function Declines Among Older Adults With Higher Blood Pressure In Mid-life: The Atherosclerosis Risk In Communities (ARIC) Study

Introduction: Greater late-life physical function decline is associated with incident adverse outcomes including disability and death. Hypertension is the strongest risk factor for stroke, the major cause of physical disability. Hypertension in mid-life has previously been associated with poor physical functioning in late-life; however, more evidence is needed to evaluate whether higher blood pressure in mid-life is associated with the rate of physical function decline during late-late in the absence of stroke. We hypothesized that elevated blood pressure in mid-life would be associated with greater physical function declines in late life.

Methods: We studied 5,559 older adults in the ARIC Study (Visit 5; mean age: 75.8 years; range: 66.7-90.9 years; 58% women; 21% Black/79% White) without prior stroke or Parkinson disease who completed the Short Physical Performance Battery (SPPB, scored 0-12). Repeated SPPB assessments occurred at Visits 6 and 7 (median follow-up: 4.2 years). The exposure was a history of elevated blood pressure (BP) (Visit 1; mean age: 52.0 years; mean gap between mid- and late-life exams: 23.7 years). BP was modeled both categorically (hypertensive: SBP 140+ mmHg, DBP 90+ mmHg, or antihypertensive medication use; pre-hypertensive: SBP 120-139 mmHg or DBP 80-89 mmHg; else normotensive) and continuously. Random-slope, random-intercept mixed models with an independent covariance structure tested the association between BP and SPPB score change, adjusted for age, sex, race-site, BMI, education, heart disease and heart failure. Continuous analysis also adjusted for antihypertensive medication use.

Results: SPPB scores declined an average of 1.60 points per 10 years (95% CI: -1.75, -1.46; p<0.001) among older adults who were normotensive in mid-life. Older adults with a previous measurement of hypertension declined an additional 0.94 points per 10 years (95% CI: -1.27, -0.60; p<0.001). Prehypertension was not statistically significantly associated with additional decline compared to mid-life normotension (estimate: -0.19 SPPB points/10 years; 95% CI: -0.53, 0.16; p=0.293). In the continuous analysis, each additional 10 mmHg higher mid-life systolic blood pressure above 120 mmHg was associated with an additional 0.24 point decline in SPPB per 10 years in late-life (95% CI: -0.31,-0.14; p<0.001).

Conclusions: Elevated BP in mid-life provides insight into the rate of physical function decline decades later, with higher mid-life systolic blood pressure corresponding with steeper declines in late-life physical function even in the absence of stroke. Future research should investigate whether elevated blood pressure at multiple points in mid-life further informs the association.

Abstract 059: Pre-stroke Physical Activity Is Associated With Lower Mortality Risk After Stroke In The Atherosclerosis Risk In Communities (ARIC) Study

Background: The association between pre-stroke PA and long-term stroke outcomes is still unclear. We examined the association of pre-stroke PA with adverse health outcomes after incident stroke in the ARIC study.

Methods: We included 881 participants with incident ischemic or hemorrhagic stroke occurring between 1993-1995 and December 31 st , 2016. Follow-up for all-cause and cardiovascular disease (CVD) mortality, CVD or recurrent stroke occurred through December 31 st , 2017, allowing for at least 1-year of follow-up after incident stroke. Pre-stroke total and domain-specific (work, sports and leisure) PA was assessed with the modified Baecke questionnaire at the baseline visit (1987-1989) and in 1993-1995. The total PA score was calculated by summing scores at both visits. Distribution-based tertiles of the summed score were derived. Cox proportional hazards models estimated the hazard ratios of adverse outcomes by tertiles of pre-stroke PA, adjusted for demographic and clinical characteristics.

Results: During a median follow-up of 3.1 years after incident stroke, 77% participants developed adverse outcome. Compared to low pre-stroke PA, high pre-stroke PA was associated with a lower risk of all-cause mortality (HR=0.78; 95% CI: 0.63-0.97, Table). In the analysis by domain-specific PA, the risk of all-cause mortality was lowest among participants in the highest tertile of work PA (HR; 95% CI=0.77; 0.62-0.96) and leisure PA (HR=0.72; 95% CI: 0.58 to 0.89) compared to the lowest tertiles. The risk of CVD mortality was also lower in the highest tertile of work PA (HR=0.45; 95% CI: 0.29-0.70) compared to the lowest tertile.

Conclusions: Higher levels of total pre-stroke PA, as well as work and leisure PA, were associated with a lower risk of mortality after incident stroke. Strategies to increase lifetime PA should be encouraged to decrease long-term mortality after stroke.

Abstract MP24: Sedentary Behavior (SB) In Mid-life And Structural Brain Magnetic Resonance Imaging (MRI) Markers Of Cerebrovascular Disease And Neurodegeneration In Late-life: The Atherosclerosis Risk In Communities Neurocognitive Study (ARIC-NCS)

Introduction: Few prospective studies have examined the associations of SB on brain MRI markers. We tested the hypotheses that higher levels of, and persistence of mid-life television viewing, a cognitively passive SB, are associated with structural brain MRI markers in late-life, and that these associations are independent from physical activity (PA).

Methods: ARIC participants (n=1,601, mean age: 76.2 years, 60.5% female, 27.2% Black) with reported television viewing at visits 1 (1987-89) and 3 (1993-95), and brain MRI in 2011-13 were included. Participants were categorized as low [never/seldom], medium [sometimes], or high [often/very often] television viewing. Persistent pattern of television viewing was quantified as the same frequency of reported television viewing at visits 1 and 3 (n=971). Imaging using 3T brain MRI quantified the presence of cerebrovascular lesions, white matter microstructural integrity and disease, and grey matter volumes using a standardized protocol. Models were adjusted for age, race-center, sex, education, APOE-ε4, smoking status, and total intracranial volume in volumetric analysis. Sampling weights were included to generalize MRI sample to the visit 5 cohort. Interactions by meeting (or not) 2018 PA guidelines were tested.

Results: Compared to low television viewing, medium and high television viewing in midlife was significantly associated with smaller deep grey matter volumes in late-life after multivariable adjustment; associations were stronger for persistent television viewing ( Table ). All other associations of midlife, or persistent midlife, television viewing with structural brain MRI markers were statistically null. Interactions with meeting PA guidelines were also non-significant.

Conclusions: Findings suggest an inverse association of mid-life television viewing with later-life deep grey matter volumes. Studies examining the associations of daily accumulated SB, and differences by SB type (active versus passive), with brain MRI markers are needed.

Abstract 073: Physical Function And Subsequent Risk Of Cardiovascular Events In Older Adults: The Atherosclerosis Risk In Communities (ARIC) Study

Background: Reduced physical function, an exemplary phenotype of aging, has been associated with cardiovascular disease (CVD). However, few studies have comprehensively investigated the association of physical function with risk of incident and recurrent CVD in community-dwelling older adults.

Methods: Physical function, evaluated with the Short Performance Physical Battery (SPPB), was assessed in the ARIC study at visit 5 (2011-2013) among 5548 participants (mean age 75±5 years, female 58%, black 22%). The SPPB score was categorized into low (0-6), intermediate (7-9), and high (10-12) physical function. We assessed the associations of SPPB categories with composite and individual outcomes of coronary heart disease (CHD), stroke, or heart failure (HF) using Cox proportional hazards models adjusting for potential confounders. We also evaluated improvement in c-statistics by adding SPPB to covariates.

Results: During a median follow-up of 6.2 years, there were 821 composite events (329 CHD, 226 stroke, and 467 HF cases). Compared to high SPPB score, low and intermediate SPPB score were robustly associated with higher risk of the composite CVD outcome (hazard ratio [HR] 1.59 [95% CI 1.29-1.95] and 1.32 [1.12-1.56], respectively) (Table). These associations were largely consistent between participants with and without a history of CVD at baseline. Among individual outcomes, low SPPB score showed the highest HR for stroke, whereas intermediate SPPB score was only significantly associated with HF. The addition of SPPB significantly improved c-statistic for composite outcome (Δc-statistic 0.006 [95% CI 0.002-0.009]), and the improvement was especially evident in participants without history of CVD (Δc-statistic 0.013 [0.003-0.023]).

Conclusions: Lower physical function was robustly associated with the risk of CVD and improved its prediction beyond established predictors in older adults. Clinicians should pay attention to physical function when managing CVD risk in older adults.

Abstract MP22: Social Isolation, Social Support, And Cognitive Decline: The Atherosclerosis Risk In Communities Study

Introduction: Recent evidence supports relationships between social engagement and cognitive function, but the importance of social engagement decades before the onset of cognitive impairment is less well described. We examined associations of midlife social isolation and social support with mid-to-late life cognitive decline.

Methods: In 14,083 participants in the Atherosclerosis Risk in Communities (ARIC) Study, social isolation was evaluated in 1990-92 by the Lubben Social Network Scale, discretized into: Isolated, and high, moderate, and low “risk” for isolation. Perceived social support, using the Interpersonal Support Evaluation List-Short Form, was discretized into tertiles. Linear mixed effects models with random intercepts and slopes were used to estimate the cross-sectional and longitudinal (1990-92 to 2011-13) associations of social isolation/social support with general cognitive performance. Models were adjusted for demographic factors and comorbidities, with effect modification explored by race and sex. We used multiple imputation by chained equations (MICE) to account for attrition.

Results: Participants were on average 57.0 years old, 56% female, and 24% Black; 3% were “isolated” and 38% reported low social support. On average, men had a higher level of social isolation and lower level of social support. White participants had lower scored risk of social isolation. Socially isolated participants had on average a 0.253 standard deviation (SD) (95% CI 0.181, 0.324) lower baseline cognitive score, but a similar rate of cognitive decline in both the first 6 (difference: 0.002 SD/year, 95% CI -0.008, 0.012) and subsequent 15 years (difference: 0.001 SD/year, 95% CI: -0.006, 0.008), compared to those with lower social isolation level. Compared to participants with the highest level of social support, participants with the lowest level of social support had on average a 0.183 SD (95% CI 0.154, 0.212) lower baseline cognitive score, with a similar rate of cognitive decline in the first 6 years (difference: -0.001 SD/year, 95% CI -0.005, 0.003), but a 0.005 SD/year (95% CI 0.002, 0.007) slower rate of cognitive decline after 6 years, mainly driven by white and male participants. MICE-imputed results did not change.

Conclusions: Although higher levels of social isolation and lower levels of social support in midlife were associated with worse cognitive function at baseline, these exposures had only a minimal impact on 20-year cognitive change. Some relationships differed by race and sex. Further studies are needed to better elucidate whether interventions addressing social isolation and support would be effective in the prevention of cognitive decline and dementia.

Abstract 031: Age-related Homeostatic Dysregulation In Midlife And Physical Function In Late Life: The Atherosclerosis Risk In Communities (aric) Study

Introduction: Age-related homeostatic dysregulation (Dm), characterized by multi-biomarker composite measures, has shown promise as a rate-of-aging metric. We tested the association of midlife Dm and its change over ~20 years of follow-up with later life physical function.

Methods: We studied 4617 ARIC cohort participants (mean age 54.8 years, 58% female, 20% Black) who completed in-person examinations from 1990-92 (baseline) through 2011-13. Dm quantifies the multivariate statistical deviation of 15 physiology-motivated biomarkers from the distribution in a healthy sample at baseline. Midlife Dm was grouped by quartiles (higher quartiles indicating greater homeostatic dysregulation) and temporal change in Dm was quantified continuously. Physical function was assessed in 2011-13 and included measures from the Short Physical Performance Battery (SPPB) including repeated chair stands, balance, 4-meter walk and grip strength. Associations were quantified using linear regression and ordinal logistic regression as applicable, adjusting for age, sex, race, and education.

Results: A graded association was observed between midlife Dm and physical functional performance in late life (Table). Compared to the 1 st quartile of midlife Dm, the odds ratio of a lower SPPB score in late life was 1.19 (95%CI 1.04, 1.35) for the 2 nd quartile, 1.63 (1.41, 1.90) for the 3 rd quartile, and 3.14 (2.60, 3.79) for the 4 th quartile. Similar associations were observed for each of SPPB components and grip strength, either modeled ordinally or continuously. Each standard deviation increase in 10-year Dm change was associated with ~2-3 times the odds of having a poorer physical functional performance.

Conclusions: Greater homeostatic dysregulation at midlife and increases in dysregulation during follow-up were associated with poorer physical function in late life. Insights into the factors that lead to progression of multisystem deterioration during midlife may highlight opportunities to preserve functional abilities in late life.

In Vivo Amyloid, Neurodegeneration, and Verbal Learning in Late Middle-Aged Hispanics

BACKGROUND

The National Institute on Aging (NIA)/Alzheimer's Association (AA) 2018 framework conceptualizes Alzheimer's disease (AD) biologically. Evidence of brain amyloid by biomarkers defines AD pathologic change and the Alzheimer's continuum. The presence of tau or neurodegeneration in the absence of amyloid defines non-AD pathologic change.

OBJECTIVE

To examine the relation of in vivo amyloid and neurodegeneration with verbal learning, one of the cognitive abilities affected early in AD, in late middle age.

METHODS

This was a cross-sectional study of amyloid and neurodegeneration biomarkers in a community-based cohort of 350 late-middle aged Hispanics without dementia (mean age: 64.15±3.34; 72.0%women). Amyloid (A) was measured as global standardized uptake value ratio (SUVR) with 18F-Florbetaben positron emission tomography (PET). Neurodegeneration (N) was ascertained as cortical thickness (CT) in AD signature areas using brain magnetic resonance imaging. We examined A/N continuously, categorically, by A/N profiles, and profile categories. The amyloid threshold for positivity was defined using the K means method. The CT threshold was defined as 2 standard deviations below the mean CT. Verbal learning was ascertained using total recall and delayed recall in the Buschke Selective Reminding test (SRT).

RESULTS

Higher cortical thickness was associated with higher performance in SRT delayed recall. Amyloid SUVR was not related to SRT performance. The low CT category was associated with lower performance in SRT delayed recall, while Amyloid categories were not related to any SRT score. The non-AD pathologic change group (A-N+) performed worse in SRT delayed recall compared to the Normal A/N profile group (A-N-).

CONCLUSION

In late middle-aged Hispanics without dementia, non-AD pathologic change, but not the Alzheimer's continuum, was related to verbal learning.

Cerebrovascular function response to prolonged sitting combined with a high-glycemic index meal: A double-blind, randomized cross-over trial

Acute prolonged sitting leads to cerebrovascular disruptions. However, it is unclear how prolonged sitting interacts with other common behaviors, including high- (HGI) and low-glycemic index (LGI) meals. Using a double-blind randomized cross-over design, this study evaluated the effects of prolonged (3 hr) sitting, with a high- (HGI; GI: 100) or low-glycemic index (LGI; GI: 19) meal on total brain blood flow (Q_Brain ) and executive function. Eighteen young, healthy, active participants (22.6 [3.1] y, 33% F, 24.3 [3.7] kg/m² ) sat for 3 hr after consuming an HGI or LGI meal. Using Doppler ultrasound to measure internal carotid (ICA) and vertebral (VA) artery blood flow, Q_Brain was calculated: (ICA blood flow + VA blood flow) × 2. Executive function was assessed using the Stroop Test and Trail Making Test-Part B. Brain fog was measured using a modified Borg Category Scale with Ratio properties (CR10). Following 3 hr of sitting, there was a significant decrease in Q_Brain with time (p = .001, ES = -0.26), though there were nonsignificant interaction (p = .216) and condition effects (p = .174). Brain fog increased (p = .024, ES = 0.27) and Stroop reaction time worsened with time (p = .001, ES: -0.40), though there were nonsignificant condition effects for brain fog (p = .612) and the Stroop test (p = .445). There was a nonsignificant condition effect (p = .729) for the Trail Making Test-Part B, but completion time improved with time (p = .001, ES = -0.40). In conclusion, 3 hr of prolonged sitting decreases Q_Brain and executive function independent of glycemic index in young, healthy adults.

Collaborative Cohort of Cohorts for COVID-19 Research (C4R) Study: Study Design

The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults at risk for coronavirus disease 2019 (COVID-19) comprising 14 established United States (US) prospective cohort studies. For decades, C4R cohorts have collected extensive data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R will link this pre-COVID phenotyping to information on SARS-CoV-2 infection and acute and post-acute COVID-related illness. C4R is largely population-based, has an age range of 18-108 years, and broadly reflects the racial, ethnic, socioeconomic, and geographic diversity of the US. C4R is ascertaining severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations, and high-quality events surveillance. Extensive pre-pandemic data minimize referral, survival, and recall bias. Data are being harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these will be pooled and shared widely to expedite collaboration and scientific findings. This unique resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including post-acute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term trajectories of health and aging.

Prospective Analysis of Leisure-Time Physical Activity in Midlife and Beyond and Brain Damage on MRI in Older Adults

OBJECTIVE

To test the hypothesis that greater levels of leisure-time moderate to vigorous intensity physical activity (MVPA) in midlife or late life are associated with larger gray matter volumes, less white matter disease, and fewer cerebrovascular lesions measured in late life, we utilized data from 1,604 participants enrolled in the Atherosclerosis Risk in Communities study.

METHODS

Leisure-time MVPA was quantified using a past-year recall, interviewer-administered questionnaire at baseline and 25 years later and classified as none, low, middle, and high at each time point. The presence of cerebrovascular lesions, white matter hyperintensities (WMH), white matter integrity (mean fractional anisotropy [FA] and mean diffusivity [MD]), and gray matter volumes were quantified with 3T MRI in late life. The odds of cerebrovascular lesions were estimated with logistic regression. Linear regression estimated the mean differences in WMH, mean FA and MD, and gray matter volumes.

RESULTS

Among 1,604 participants (mean age 53 years, 61% female, 27% Black), 550 (34%), 176 (11%), 250 (16%), and 628 (39%) reported no, low, middle, and high MVPA in midlife, respectively. Compared to no MVPA in midlife, high MVPA was associated with more intact white matter integrity in late life (mean FA difference 0.13 per SD [95% confidence interval (CI) 0.004, 0.26]; mean MD difference -0.11 per SD [95% CI -0.21, -0.004]). High MVPA in midlife was also associated with a lower odds of lacunar infarcts (odds ratio 0.68, 95% CI 0.46, 0.99). High MVPA was not associated with gray matter volumes. High MVPA compared to no MVPA in late life was associated with most brain measures.

CONCLUSION

Greater levels of physical activity in midlife may protect against cerebrovascular sequelae in late life.

Longitudinal Associations of Midlife Accelerometer Determined Sedentary Behavior and Physical Activity With Cognitive Function: The CARDIA Study

Background To determine if accelerometer measured sedentary behavior (SED), light-intensity physical activity (LPA), and moderate-to-vigorous-intensity physical activity (MVPA) in midlife is prospectively associated with cognitive function. Methods and Results Participants were 1970 adults enrolled in the CARDIA (Coronary Artery Risk Development in Young Adults) study who wore an accelerometer in 2005 to 2006 (ages 38-50 years) and had cognitive function assessments completed 5 and/or 10 years later. SED, LPA, and MVPA were measured by an ActiGraph 7164 accelerometer. Cognitive function tests included the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop Test. Compositional isotemporal substitution analysis examined associations of SED, LPA, and MVPA with repeated measures of the cognitive function standardized scores. In men, statistical reallocation of 30 minutes of LPA with 30 minutes of MVPA resulted in an estimated difference of SD 0.07 (95% CI, 0.01-0.14), SD 0.09 (95% CI, 0.02-0.17), and SD -0.11 (95% CI, -0.19 to -0.04) in the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop scores, respectively, indicating better performance. Associations were similar when reallocating time in SED with MVPA, but results were less robust. Reallocation of time in SED with LPA resulted in an estimated difference of SD -0.05 (95% CI, -0.06 to -0.03), SD -0.03 (95% CI, -0.05 to -0.01), and SD 0.05 (95% CI, 0.03- 0.07) in the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop scores, respectively, indicating worse performance. Associations were largely nonsignificant among women. Conclusions Our findings support the idea that for men, higher-intensity activities (MVPA) may be necessary in midlife to observe beneficial associations with cognition.