Kaiser Healthy Aging And Diverse Life Experiences Research Articles

Diagnostic accuracy of cognitive assessment in diverse older adults: effects of normative sample and demographic adjustments

AbstractBackgroundRacial and ethnic disparities in ADRD diagnosis are well documented but remain poorly understood. Clinical ADRD diagnosis relies on neuropsychological assessment, which is interpreted by comparing individual performance to demographically adjusted reference group norms. Differential use of demographic adjustment procedures and sources of normative data may compromise diagnostic accuracy of neuropsychological findings in diverse individuals. Using two different demographic adjustment approaches derived from two distinct normative samples, we generated cognitive impairment categories and evaluated their associations with longitudinal trajectories of independent executive functioning and memory scores.MethodParticipants were 717 older adults (age: 77.5±6.9, 56% women) enrolled in the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study who completed up to 3 annual visits. The main predictor was cognitive impairment category (no impairment, single‐domain, multiple‐domain) based on Uniform Data Set Neuropsychological Battery (UDSNB) scores at baseline. UDSNB scores were either demographically unadjusted or adjusted (age, sex, education, and race/ethnicity) using data from the National Alzheimer’s Coordinating Center (NACC; N = 8313, 16% Black, 84% White) or KHANDLE (N = 397, 26% Asian, 18% Black, 30% LatinX, 26% White) samples. Linear mixed effect models were used to examine the associations between differentially derived cognitive impairment categories with longitudinal changes on episodic memory and executive functioning composites from an independent cognitive battery (Spanish and English Neuropsychological Assessment Scales, SENAS).ResultCognitive impairment categories derived from the KHANDLE sample were more strongly associated in all four racial and ethnic groups with longitudinal decline on episodic memory compared to the NACC sample‐derived categories (Figure 1). Similar, albeit attenuated, effects were observed in relation to longitudinal decline on the executive function composite. There were no clear differences in the associations between cognitive impairment categories with executive functioning or memory decline using demographically adjusted vs. unadjusted scores.ConclusionOur results highlight the need for greater representation of diverse individuals in normative samples underlining the limitations of the NACC‐derived normative algorithms for cognitive assessment of individuals from diverse populations. Further investigations into the clinical value of the practice of demographic adjustments are also warranted.

Differences in the association between midlife hypertension status and late‐life cognition and cognitive change: results from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study

AbstractBackgroundThis study evaluates the association of midlife hypertension status and domain‐specific late‐life cognitive change allowing for possible differences by sex.MethodThe Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort is a multi‐ethnic study of 1,712 Kaiser Permanente Northern California members age 65+ at enrollment in 2017. For 1,696 participants, we categorized the last examined clinical blood pressure measures from 1964‐1985 (mean age = 37.5) as hypotensive, normotensive, prehypertensive, or hypertensive. Verbal episodic memory and executive function were assessed using Spanish and English Neuropsychological Assessment Scales across three interview waves over 4 years and scores were z‐standardized to the baseline. Sex‐stratified linear mixed models with random intercepts estimated the associations of midlife hypertension status with domain‐specific baseline cognition and cognitive change using years since baseline as timescale. Models adjusted for age at blood pressure measurement, KHANDLE baseline age, race, ethnicity, education, practice effects, and interview mode (phone vs in‐person).ResultA greater proportion of men than women had midlife pre‐hypertension (44% vs 31%) or hypertension (21% vs 11%) (Table 1). Among men and women, midlife hypertension status was not associated with baseline executive function or verbal episodic memory (Table 2). Compared to men with normal midlife blood pressure, those with midlife hypotension (b = ‐0.10, 95% CI: ‐0.17, ‐0.04) or midlife hypertension experienced steeper declines in executive functioning (b = ‐0.05, 95% CI: ‐0.10, ‐0.004). Among women, only midlife hypertension was associated with decline in executive function (b = ‐0.04 95% CI: ‐0.09, 0.003), though not significantly different from normotensive women. Compared to normotensive men, those with midlife hypotension (b = ‐0.17, 95%CI: ‐0.27, ‐0.07) and those with pre‐hypertension (b = ‐0.06, 95% CI: ‐0.12, ‐0.004) experienced steeper decline in verbal episodic memory. Among women, only midlife hypertension was associated with steeper declines executive function (b = ‐0.04, 95% CI: ‐0.09, 0.003), though not significantly different from normotensive women. Though effect estimates of midlife hypertension status on cognitive outcomes differed by sex, these differences were not statistically significant.ConclusionBoth hypotension and hypertension 30‐50 years prior to cognitive assessments predicted accelerated cognitive decline in older men. Patterns were less consistent for women but not statistically distinguishable from associations among men.

Social Networks and MRI measures of Brain Injury in Racially and Ethnically Diverse Populations

AbstractBackgroundSocial networks may influence late‐life cognition directly via affecting brain structures or indirectly through enhancing cognitive resilience – i.e., the ability to maintain cognitive function in the presence of neurodegeneration. This study assesses the associations of social networks with markers of neurodegeneration, and determines whether social networks modify the associations between these markers and cognitive function.MethodWe pooled data from three harmonized cohorts of Kaiser Permanente Northern California members: the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE)study, the Study of Healthy Aging in African Americans (STAR), and the LifeAfter90 (LA90) Study. Social network sizes were calculated by summing the number of living children, spouse, and close relatives and friends. Neuroimaging markers included total brain volume (TBV), hippocampal volume (HCV), and white matter hyperintensity volume (WMH). Volumetric measures were normalized using a residual approach, which regressed intracranial volume (ICV) on volumetric measures to predict the ICV‐adjusted volume. Executive function and verbal episodic memory were measured by the Spanish and English Neuropsychological Assessment Scales and were z‐standardized. Linear regression models estimated the associations between social network size and each neuroimaging marker, adjusting for age, sex, race and ethnicity, education, cohort, and Activities of Daily Living (ADLs). We included an interaction term between social networks and neuroimaging markers to evaluate whether the relationships between imaging markers and cognitive function differed by social networks.ResultThe pooled sample’s average age was 76 (SD 11) years (59% female; 47% Black) (Table 1). In the fully adjusted models, the mean differences in injury markers did not differ by social network size (Figure 1). However, the associations of HCV and WMH with executive function (βsocial network*WMH = 0.09, 95% CI 0.01,0.18; βsocial network*HCV = ‐0.08, 95% CI ‐0.15, ‐0.01) were stronger among participants with smaller social networks (Figure 2).ConclusionIn this cross‐sectional study of racially and ethnically diverse older adults, larger social networks attenuated the associations between neurodegeneration markers and executive function. These findings suggest that larger social networks may promote cognitive resilience.

Psychometric evaluation of the Everyday Discrimination Scale in KHANDLE

AbstractBackgroundStructural racism manifests in differential experiences of everyday discrimination for racialized and minoritized groups. The Everyday Discrimination Scale (EDS) assesses subjective experiences of unfair treatment in everyday social situations. The goal of this study is to evaluate the psychometric performance of the EDS within racialized groups and specifically to evaluate if the EDS measures a unidimensional construct.MethodData was from a diverse sample of community‐dwelling older adults in Northern California (N = 1,590 participants) from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study (Non‐Hispanic (NH) Black = 411; NH Asian = 380; NH white = 477; LatinX = 322). The EDS is a 9‐item scale with six response categories that range from “almost everyday” to “never”. The EDS was administered to each participant at baseline. We used confirmatory factor analysis to evaluate unidimensionality in the combined sample and in the 4 racialized subgroups. We identified model modifications that improved fit in a random 50% subsample of each group and tested fit of the modified model in the other random 50%.ResultLoadings for all items on the main factor were > 0.50 for each racialized group and for the full sample. There were issues with model fit with the full sample, which were improved when residual correlations were set between items “courtesy” and “respect” and between “insult” and “threat”. Cross‐validated model fit was improved after adding these parameters to the model and was best in groups racialized as Black and LatinX (Table 1).ConclusionThe EDS is a commonly used assessment in aging studies purporting to capture effects of discrimination on a variety of health and psychosocial outcomes. Our study show that all EDS items are strongly associated with underlying construct of discrimination in all groups, though differentially. Further work is needed to determine if the identified residual correlations point to additional factors that are important to measure. Model fit suggests the EDS is better suited to capture discrimination in groups racialized as Black and LatinX groups, which is consistent with the development of the scale. This study expands the literature by carefully examining the measurement properties of the EDS among four racialized groups.

17 Emotional and Instrumental Support as Protective Factors in Cognitive Aging Among Black and Hispanic/Latinx Older Adults

Objective:Social support may protect against Alzheimer’s disease and related dementias (ADRD), potentially through emotional or instrumental support elements. Black and Hispanic/Latinx older adults bear a disproportionate burden of ADRD. However, independent effects of emotional and instrumental support on cognition, a primary indicator of ADRD risk, are largely understudied in these groups. Guided by the differential vulnerability hypothesis – the theoretical framework which posits that systemic racism disadvantages Black and Hispanic/Latinx individuals’ health – we hypothesize that emotional and instrumental support may be particularly important to protect against worse cognition for Black and Hispanic/Latinx older adults, who often have fewer resources due to these inequalities (e.g., wealth, educational opportunities) to otherwise maintain health. Using the NIH Toolbox Emotion Module measures of emotional (e.g., the extent to which individuals can rely on others in challenging times) and instrumental support (e.g., the extent to which individuals can rely on others for assistance in daily activities), we aimed to identify positive social support factors (i.e., emotional and instrumental support) that may protect against ADRD risk (i.e., longitudinal executive function and memory performance) among Black and Hispanic/Latinx older adults.Participants and Methods:Participants were 362 Black and 265 Hispanic/Latinx adults aged 65-89 (63% female, average age=75) from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study who completed baseline and up to two additional waves of assessments (every 1.5 years), including questionnaires, neuropsychological evaluations, and the NIH toolbox. Predictors included baseline covariates (i.e., age, language of test administration, gender, education, income, self-rated health) and NIH toolbox emotional and instrumental support variables. Outcomes were baseline and longitudinal memory (visual and verbal episodic memory) and executive functioning (verbal fluency and working memory) composites from the Spanish and English Neuropsychological Assessment Scales (SENAS). Latent growth curve models were conducted separately in Black and Hispanic/Latinx participants to estimate effects of emotional and instrumental support on baseline cognition and subsequent change in each domain.Results:Black participants reported greater emotional support. There were no group differences in levels of instrumental support. Greater instrumental support was associated with better initial memory (standardized β= .194, 95%CI: [.063, .325]) among Black participants but not among Hispanic/Latinx participants. In Hispanic/Latinx participants, greater emotional support was associated with better initial executive functioning (standardized β= .215, 95%CI: [.079, .350]. Emotional support was not associated with either cognitive domain in Black participants. There were no associations between emotional or instrumental support on cognitive change in either group.Conclusions:Results point to differences between Black and Hispanic/Latinx older adults in the impact of specific aspects of social support on different cognitive domains. Positive associations between instrumental support and baseline memory in Black participants and between emotional support and executive functioning in Hispanic/Latinx participants suggest unique cognitive consequences of social support across groups. Differences in the role of specific types of social supports may be useful in identifying intervention targets specifically for Black and Hispanic/Latinx older adults, who are disproportionately affected by ADRD. Future research will examine these constructs using multiple group models to test these associations more rigorously.

Timing and level of educational attainment and late-life cognition in the KHANDLE study.

The timing of educational attainment may modify its effects on late-life cognition, yet most studies evaluate education only at a single time point. Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study cohort participants (N=554) reported educational attainment (dichotomized at any college education) at two time points, and we classified them as having low, high, or later-life high educational attainment. Linear mixed-effects models estimated associations between educational attainment change groups and domain-specific cognitive outcomes (z-standardized). Compared to low educational attainment, high (β=0.59 SD units; 95% confidence interval [CI]: 0.39, 0.79) and later-life high educational attainment (β =0.22; 95% CI: 0.00, 0.44) were associated with higher executive function. Only high educational attainment was associated with higher verbal episodic memory (β = 0.27; 95% CI: 0.06, 0.48). Level and timing of educational attainment are both associated with domain-specific cognition. A single assessment for educational attainment may inadequately characterize protective associations with late-life cognition. Few studies have examined both level and timing of educational attainment on cognition. Marginalized populations are more likely to attain higher education in adulthood. Higher educational attainment in late life is also associated with higher cognition.

Characterizing oldest‐old SuperAgers based on cognitive domains and demographic factors: The Life After 90 study

AbstractBackgroundSuperAgers are individuals who maintain superior cognitive performance despite advanced age. Most studies define SuperAgers as superior performers only in episodic memory. Our aim was to assess in a diverse oldest‐old cohort if superior performance in one domain indicates superior performance in other domains and explore demographic characteristics.MethodsThe LifeAfter90 study is a multi‐ethnic cohort of members of Kaiser Permanente Northern California aged 90 or older. Baseline verbal episodic memory (VEM), semantic memory (SM), and executive function (EF) were evaluated using the Spanish and English Neuropsychological Assessment Scale (SENAS). SuperAgers were individuals who scored above the mean of domain and race‐specific SENAS scores from a reference cohort aged 65‐70 years. The reference group were similar participants from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study. To assess the association between age, sex, education, and being a SuperAger, odds ratios (OR) and 95% confidence interval (CI) were calculated using multiple logistic regression.ResultsThe 617 study participants (236 men and 381 women) had a mean age of 92.9 years (Table1). 53.6% of individuals were SuperAgers in one domain, 22.8% in any two domains, and 7.7% in all three domains. 7.0% of individuals were SuperAgers in SM and EF, 4.5% in VEM and EF, and 3.5% in VEM and SM (Figure1). SuperAgers were younger than non‐SuperAgers. Women were more likely to be SuperAgers in VEM (OR = 2.13; 95%CI: 1.43,3.18) and EF (OR = 2.18; 95%CI: 1.44,3.30) and less likely in SM (OR = 0.49; 95%CI: 0.34,0.71) compared to men. Higher education was related to being a SuperAger in SM (OR = 1.85; 95%CI: 1.28,2.67) and EF (OR = 2.56; 95%CI: 1.74,3.78) but not VEM (Table2).ConclusionIn this diverse cohort of oldest‐old SuperAgers we found that exceptional episodic memory performance does not indicate exceptional performance in other cognitive domains. Education was not a predictor of exceptional performance in all domains. Future work should investigate predictors of exceptional cognitive aging after age 90.

Association of Early Adulthood Hypertension and Blood Pressure Change With Late-Life Neuroimaging Biomarkers

The association between hypertension developed before midlife and late-life brain health is understudied and, because of the cardioprotective benefits of estrogen before menopause, may differ by sex. To assess the association of early adulthood hypertension and blood pressure (BP) change with late-life neuroimaging biomarkers and examine potential sex differences. This cohort study used data from the Study of Healthy Aging in African Americans (STAR) and Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study, which were harmonized longitudinal cohorts of racially and ethnically diverse adults aged 50 years and older from the San Francisco Bay area and Sacramento Valley in California. The STAR was conducted from November 6, 2017, to November 5, 2021, and the KHANDLE study was conducted from April 27, 2017, to June 15, 2021. The current study included 427 participants from the KHANDLE and STAR studies who received health assessments between June 1, 1964, and March 31, 1985. Regional brain volumes and white matter (WM) integrity were measured via magnetic resonance imaging between June 1, 2017, and March 1, 2022. Hypertension status (normotension, transition to hypertension, and hypertension) and BP change (last measure minus first measure) were assessed at 2 multiphasic health checkups (MHCs; 1964-1985) in early adulthood (ages 30-40 years). Regional brain volumes and WM integrity were measured using 3T magnetic resonance imaging and z standardized. General linear models adjusted for potential confounders (demographic characteristics and study [KHANDLE or STAR]) were used to assess the association of hypertension and BP change with neuroimaging biomarkers. Sex interactions were tested. Among 427 participants, median (SD) ages were 28.9 (7.3) years at the first MHC, 40.3 (9.4) years at the last MHC, and 74.8 (8.0) years at neuroimaging. A total of 263 participants (61.6%) were female and 231 (54.1%) were Black. Overall, 191 participants (44.7%) had normotension, 68 (15.9%) transitioned to hypertension, and 168 (39.3%) had hypertension. Compared with participants who had normotension, those who had hypertension and those who transitioned to hypertension had smaller cerebral volumes (hypertension: β = -0.26 [95% CI, -0.41 to -0.10]; transition to hypertension: β = -0.23 [95% CI, -0.44 to -0.23]), with similar differences in cerebral gray matter volume (hypertension: β = -0.32 [95% CI, -0.52 to -0.13]; transition to hypertension: β = -0.30 [95% CI, -0.56 to -0.05]), frontal cortex volume (hypertension: β = -0.43 [95% CI, -0.63 to -0.23]; transition to hypertension: β = -0.27 [95% CI, -0.53 to 0]), and parietal cortex volume (hypertension: β = -0.22 [95% CI, -0.42 to -0.02]; transition to hypertension: β = -0.29 [95% CI, -0.56 to -0.02]). Participants with hypertension also had smaller hippocampal volume (β = -0.22; 95% CI, -0.42 to -0.02), greater ventricular volumes (lateral ventricle: β = 0.44 [95% CI, 0.25-0.63]; third ventricle: β = 0.20 [95% CI, 0.01-0.39]), larger free water volume (β = 0.35; 95% CI, 0.18-0.52), and lower fractional anisotropy (β = -0.26; 95% CI, -0.45 to -0.08) than those who had normotension. Holding hypertension status constant, a 5-mm Hg increase in systolic BP was associated with smaller temporal cortex volume (β = -0.03; 95% CI, -0.06 to -0.01), while a 5-mm Hg increase in diastolic BP was associated with smaller parietal cortex volume (β = -0.06; 95% CI, -0.10 to -0.02). The negative association of hypertension and BP change with regional brain volumes appeared stronger in men than women for some regions. In this cohort study, early adulthood hypertension and BP change were associated with late-life volumetric and WM differences implicated in neurodegeneration and dementia. Sex differences were observed for some brain regions whereby hypertension and increasing BP appeared more detrimental for men. These findings suggest that prevention and treatment of hypertension in early adulthood is important for late-life brain health, particularly among men.

Is Poor Sleep Quality Associated with Lower Levels of and Faster Declines in Cognitive Function? Results from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study

AbstractBackgroundPoor sleep quality has been linked to worse cognitive function, but most research has been conducted in predominantly White samples. We investigated whether poorer sleep quality is associated with lower levels of and faster declines in cognition and whether these associations differ by race/ethnicity.MethodWe used data from KHANDLE (N = 1,438; mean age: 75.7 years), a multi‐ethnic cohort of Kaiser Permanente Northern California members. We created a global sleep score by summing scores on six sleep components assessed by a modified Pittsburgh Sleep Quality Index: subjective sleep quality, latency, duration, disturbances, sleep medication use, and daytime dysfunction. Executive function (EF) and verbal memory (VM) were assessed by the Spanish and English Neuropsychological Assessment Scale (3 waves each separated by 18 months). Linear regression models assessed the associations between sleep quality and baseline cognition. To understand associations with cognitive decline, we fit linear mixed‐effect models with random intercepts accounting for practice effects and interview mode. Covariates included baseline age, gender, income, education, depression, physical activity, and central adiposity. We included interactions between time (years since baseline) and sleep and time and covariates to determine associations between sleep and cognitive decline. To assess racial/ethnic differences, we included interactions (race*sleep in linear regression models and time*sleep*race in mixed‐effect models for each racial/ethnic category) and performed likelihood ratio tests to determine the presence of interactions.ResultAfter adjusting for covariates, sleep quality was not associated with baseline EF or VM and the associations did not differ by race/ethnicity (Figure 1). Overall, poorer sleep quality was associated with faster declines in EF (β time*sleep = ‐0.02, 95% CI ‐0.03, ‐0.004: Figure 2). The associations between sleep and declines in EF were modified by race/ethnicity (β time*sleep*Black = ‐0.06, 95% CI ‐0.09, ‐0.03), such that poorer sleep quality was associated with faster declines in EF among Black adults only (β time*sleep = ‐0.06, 95% CI ‐0.08, ‐0.04; Figure 3).ConclusionPoorer sleep quality was associated with faster cognitive decline, and the association was particularly strong among Black older adults. Further research is needed to elucidate the mechanisms through which sleep influences cognitive decline among Black populations.

Racial and Ethnic Differences in Occupational Complexity and Late‐Life Cognition

AbstractBackgroundStructural racism affects employment opportunities, resulting in occupational segregation and potential racial and ethnic health disparities. Research examining the association between occupational complexity and late‐life cognition within and across racial and ethnic groups is limited. We aim to address this research gap using the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort of Asian, Black, Latino and White community‐dwelling participants aged 65+ years.MethodsWe linked occupational complexity scores (from the Dictionary of Occupational Titles) for data (range: 0‐6), people (0‐8), and things (0‐7) to self‐reported main lifetime occupation. We assessed baseline domain‐specific cognition (executive functioning, verbal episodic memory, and semantic memory) using the Spanish and English Neuropsychological Assessment Scales. Using linear regression models, we estimated associations between each occupational complexity measure and domain‐specific z‐scores, adjusting for age, sex, race and ethnicity, and education. We also assessed effect modification by race and ethnicity.ResultsAmong 1,548 participants (mean age = 76 years), 24% identified as Asian, 27% as Black, 19% as Latino, 29% as White, and 50% had a college degree or higher (Table 1). Occupational complexity with data and people varied across race and ethnicity (p‐value: >0.001 and 0.016, respectively), but not for complexity with things. Greater occupational complexity with data was associated with higher executive function (β = 0.05 SD units; 95% CI:0.02‐0.09), semantic memory (0.07 SD units; 95% CI:0.04‐0.11) and verbal episodic memory (0.06 SD units; 95% CI:0.02‐0.10) (Figure 1). Complexity with people was associated with higher executive function and semantic memory only. Complexity with things was not associated with any cognitive domain. Effect modification by race and ethnicity was significant, such that the association between greater occupational complexity with data and higher semantic memory was stronger among Latinos, compared to other racial groups.ConclusionWithin a diverse cohort, greater occupational complexity with data and people were associated with higher late‐life cognition. Occupational complexity scores varied by race and ethnicity, as well as its associations with cognitive domains. These findings suggest that racial and ethnic differences in occupational complexity may contribute to cognitive health disparities.

Accounting for lack of representation in dementia research: Generalizing KHANDLE study findings on the prevalence of cognitive impairment to the California older population.

Most dementia studies are not population-representative; statistical tools can be applied to samples to obtain critically-needed population-representative estimates, but are not yet widely used. We pooled data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study and the California Behavioral Risk Factor Surveillance System (CA-BRFSS), a population-representative study. Using weights accounting for sociodemographic/health differences between KHANDLE and CA-BRFSS, we estimated cognitive impairment prevalence and age- and sex-adjusted racial/ethnic inequalities in California adults 65+ without prior dementia diagnosis. After weighting KHANDLE, the estimated cognitive impairment prevalence in California was 20.3% (95% confidence interval 17.8-23.0); unweighted prevalence was 24.8% (23.1%-26.6%). Inequalities (larger prevalences) were observed among Black and Asian groups versus whites. We used a novel statistical approach to estimate population-representative cognitive impairment prevalence and inequalities. Such statistical tools can help obtain population-representative estimates from existing studies and inform efforts to reduce racial/ethnic disparities.

Association of Social Integration with Cognitive Status in a Multi-Ethnic Cohort: Results From the Kaiser Healthy Aging and Diverse Life Experiences Study.

We evaluated overall and race-specific relationships between social integration and cognition in older adults. Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort participants included 1343 Asian, Black, Latino, or non-Latino White Kaiser Permanente Northern California members. We estimated the effect of social integration on verbal episodic memory, semantic memory, and executive function derived from the Spanish and English Neuropsychological Assessment (SENAS) Scales. Social integration scores included marital status; volunteer activity; and contact with children, relatives, friends, and confidants. We estimated covariate-adjusted linear mixed-effects models for baseline and 17-month follow-up cognition. Social integration was associated with higher baseline cognitive scores (average = 0.066 (95% confidence interval: 0.040, 0.092)) overall and in each racial/ethnic group. The association did not vary by race/ethnicity. Social integration was not associated with the estimated rate of cognitive change. In this cohort, more social integration was similarly associated with better late-life cognition across racial/ethnic groups.

Association of social integration with cognitive status: results from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study

AbstractBackgroundLack of strong social ties is associated with numerous morbidities including adverse late‐life cognitive outcomes. Prior work on social integration and cognition has been conducted in predominantly White cohorts. We evaluated the relationships between social integration and cognition in diverse older adults from major racial/ethnic groups in the United States using data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study.MethodKHANDLE is a multi‐ethnic study of 1712 Kaiser Permanente Northern California members age 65+. Social integration was assessed using the Berkman‐Syme Social Network Index. A score ranging from 0 to 6 was calculated by assigning 1 point for each of the following domains: being married/partnered, volunteer activity, having monthly contact with children, relatives, and friends and daily contact with confidante (Figure 1). Cognition included three domains derived from the Spanish and English Neuropsychological Assessment Scales: verbal episodic memory (for White, Black and Latino participants), semantic memory and executive function. Covariate‐adjusted linear mixed‐effects models estimated a single association of social integration with cognition applicable to all three cognitive domains for the full sample and by race/ethnicity. Core models adjusted for age, gender, race, and education (years); expanded models further adjusted for variables that could either be determinants or consequences of social integration, including weekly alcohol use, average score for combined activities of daily living (ADL) and instrumental ADL, and income. We repeated these analyses using frequency of contact with confidante as the primary exposure.ResultHigher social integration score was associated with better cognition in core covariate‐adjusted models (β=0.065 (0.039, 0.091)); the association attenuated slightly when adjusting for expanded covariates (β=0.045 (0.019, 0.071)). In race‐stratified core models, higher social integration scores were associated with better cognition among Asian, Black, Latino, and White participants. In expanded models patterns were similar, but the association remained statistically significant only for Black participants (Table 1). Seeing a confidante daily was associated with higher cognition in the pooled model and for Asian participants (Table 2).ConclusionOur findings suggest that social integration and seeing a confidante daily were associated with better cognition across the four racial/ethnic groups.

Perceived Discrimination, Nativity, and Cognitive Performance in a Multiethnic Study of Older Adults: Findings From the Kaiser Healthy Aging and Diverse Life Experiences Study.

Despite growing research on the association between discrimination and disparities in cognitive aging, an evidence gap remains on how the association varies by racial/ethnic group. This study evaluates the associations of experiences of discrimination with cognitive function and whether these associations varied by race/ethnicity and nativity. Using the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort (N = 1 712) with approximately equal groups of Black, White, Latino, and Asian community-dwelling older adults aged 65 years and older, we evaluated the associations between self-reported experiences of everyday and major lifetime discrimination with overall cognitive performance and domain-specific cognition (verbal episodic memory, semantic memory, and executive functioning) across race/ethnicity and nativity. Linear regression models examined the cross-sectional association between self-reported experiences of everyday and major lifetime discrimination with z-standardized coefficients for cognition. We tested for effect modification by race and nativity. All models controlled for age, sex, and education. Among KHANDLE participants (mean age: 76 years; SD: 6.8), everyday discrimination was not associated with cognitive scores. Major lifetime discrimination was associated with better average cognitive scores among Black participants but not among other racial/ethnic groups. Major lifetime discrimination was associated with better average cognitive scores among U.S.-born but not among non-U.S.-born individuals. Our findings do not imply that discrimination improves cognition, but rather suggest that future research should include more detailed measures on discrimination and unfair treatment that could help disentangle the extent to which relationships are causal or reflect some other underlying factor.

Measuring Cognitive Health in Ethnically Diverse Older Adults.

Understanding racial/ethnic disparities in late-life cognitive health is a public health imperative. We used baseline data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study to examine how age, education, gender, and clinical diagnosis, a proxy for brain health, are associated with cross-sectional measures of cognition in diverse racial/ethnic groups. Comprehensive measures of cognition were obtained using the Spanish and English Neuropsychological Assessment Scales and the National Institutes of Health Toolbox Cognitive Health Battery in a sample of 1,695 KHANDLE participants (Asians 24%, Blacks 26%, Latinos 20%, Whites 29%). A 25% random subsample was clinically evaluated and diagnosed with normal cognition, mild cognitive impairment (MCI), or dementia. Cognitive test scores were regressed on core demographic variables and diagnosis in the combined sample and in multiple group analyses stratified by racial/ethnic group. Race/ethnicity and education were variably associated with test scores with strongest associations with tests of vocabulary and semantic memory. Older age was associated with poorer performance on all measures, and gender differences varied across cognitive tests. Clinical diagnosis of MCI or dementia was associated with average decrements in test scores that ranged from -0.41 to -0.84 SD, with largest differences on tests of executive function and episodic memory. With few exceptions, associations of demographic variables and clinical diagnosis did not differ across racial/ethnic groups. The robust associations of cognitive test results with clinical diagnosis independent of core demographic variables and race/ethnicity support the validity of cognitive tests as indicators for brain health in diverse older adults.

Racial/Ethnic Disparities in Young Adulthood and Midlife Cardiovascular Risk Factors and Late-life Cognitive Domains: The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study.

Midlife cardiovascular risk factors (CVRF) increase dementia risk. Less is known about whether CVRF identified before midlife impact late-life cognition in diverse populations. Linear regression models examined hypertension, hyperlipidemia, and overweight/obesity at ages 30 to 59 with late-life executive function, semantic memory, verbal episodic memory, and global cognition in a cohort of Asians, blacks, Latinos, and whites (n=1127; mean age=75.8, range=65 to 98). Models adjusted for age at CVRF, age at cognitive assessment, sex, race/ethnicity, participant education, and parental education. Overall, 34% had 1 CVRF at ages 30 to 59; 19% had 2+. Blacks (26%) and Latinos (23%) were more likely to have 2+ CVRF than Asians (14%) or whites (13%). Having 2+ CVRF was associated with lower global cognition [β=-0.33; 95% confidence interval (CI)=-0.45, -0.21], executive function (β=-0.26; 95% CI=-0.39, -0.13), verbal episodic memory (β=-0.34; 95% CI=-0.48, -0.20), and semantic memory (β=-0.20; 95% CI=-0.33, -0.07). Interaction by age (P=0.06) indicated overweight/obesity was negatively associated with executive function at ages 30 to 39 but not at ages 40 to 59. Race/ethnic-specific effects showed disparities in CVRF prevalence impact population disparities in late-life cognition. Being overweight/obese in early adulthood and having 2+ CVRF in early adulthood/midlife are modifiable targets to redress racial/ethnic disparities in cognitive impairment and dementia.

Cognitive impairment in racially/ethnically diverse older adults: Accounting for sources of diagnostic bias.

IntroductionThe Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study enrolled Asian, Black, Latino, and White adults ages 65+ without prior dementia diagnosis (N = 1709). We evaluated the prevalence of cognitive impairment (mild cognitive impairment or dementia) accounting for potential biases.MethodsA random subgroup (N = 541) received clinical evaluation and others were evaluated if they failed a cognitive screen. Diagnoses were made under two conditions: (1) demographics‐blind, based on clinical exam and demographically adjusted neuropsychological test scores; and (2) all available information (clinical exam, demographics, and adjusted and unadjusted test scores).ResultsCognitive impairment prevalence was 28% for blinded‐adjusted diagnosis and 25% using all available information. Black participants had higher impairment rates than White (both conditions) and Latino (blinded‐adjusted diagnosis) participants. Incomplete assessments negatively biased prevalence estimates for White participants.DiscussionRacial/ethnic disparities in cognitive impairment were amplified by attrition bias in White participants but were unaffected by type of test norms and diagnosticians’ knowledge of demographics.

Physical Performance and Cognition in a Diverse Cohort: Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study.

The authors assessed the cross-sectional association of physical function measures with cognition in the Kaiser Healthy Aging and Diverse Life Experiences Cohort. Analyses included 1369 participants (24% Asian, 26% Black, 18% Latino, 32% White). Grip strength was measured using a hand-held dynamometer (kilograms) and gait speed was measured over a 4-m walk (seconds/meter). The Spanish and English Neuropsychological Assessment Scales was used to evaluate cognitive domains of executive function, semantic memory, and verbal episodic memory. Physical function measures (per SD) were associated with cognitive test z-scores in linear regression models adjusted for demographic, behavioral, and clinical factors. Racial/ethnic differences were tested using interaction terms and stratification. Stronger grip was associated with better executive function [β=0.10 (95% confidence interval, 0.05-0.15)], semantic memory [β=0.13 (0.09-0.18)] and verbal episodic memory [β=0.07 (0.02-0.13)] with no racial/ethnic differences. Faster gait was associated with better executive function [β=0.29 (0.22-0.36)], semantic memory [β=0.23 (0.16-0.30)], and verbal episodic memory [β=0.20 (0.13-0.27)]; however, the association between gait speed and executive function varied by race/ethnicity with the strongest associations in Asians and Whites. Across race/ethnicity, grip strength and gait speed were associated with cognition with racial/ethnic differences in the association of gait speed and executive function.

Generation and age of immigration on later life cognitive performance in KHANDLE.

We examined the association of generational status and age at immigration with later life cognitive outcomes in a diverse sample of Latinos and Asian Americans. Baseline data were obtained from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study, and a prospective cohort is initiated in 2017. Older adults in Northern California. Our cohort consisted of Asians (n = 411) and Latinos (n = 340) who were on average 76 years old (SD = 6.8). We used multivariable linear regression models to estimate associations between generational status and age at immigration (collapsed into one five-level variable) with measures of verbal episodic memory, semantic memory, and executive function, adjusting for age, gender, race and ethnicity, and own- and parental education. Generational status and age at immigration were associated with cognitive outcomes in a graded manner. Compared to third-generation or higher immigrants, first-generation immigration in adulthood was associated with lower semantic memory (β = -0.96; 95% CI: -1.12, -0.81) than immigration in adolescence (β = -0.68; 95% CI: -0.96, -0.41) or childhood (β = -0.28; 95% CI: -0.49, -0.06). Moreover, immigration in adulthood was associated with lower executive function (β = -0.63; 95% CI: -0.78, -0.48) than immigration in adolescence (β = -0.49; 95% CI: -0.75, -0.23). Similarly, compared to third-generation individuals, first-generation immigrants had lower executive functioning scores. Our study supports the notion that sociocontextual influences in early life impact later life cognitive scores. Longitudinal studies are needed to further clarify how immigration characteristics affect cognitive decline.

Do benefits of own education for cognition differ by parental education? Influence of intergenerational educational trajectories and cognitive performance in the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort

AbstractBackgroundLittle is known about the influence of parental education on late life cognition or whether parental education modifies the association between own education and cognitive outcomes. Parental education influences own educational access/attainment as well as early cognitive environments and resources (social, financial capital) known to affect health. We investigated whether benefits of own education differed by parental education using intergenerational education trajectories.MethodsThe Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort is a diverse sample (approximately equal White, African‐American, Asian, and Latinx) of long‐term members of a managed care organization; cognitive domains of verbal episodic memory, semantic memory, and executive functioning were obtained using the Spanish and English Neuropsychological Assessment Scales (SENAS). Parental education (low defined as either parent with <9 years of schooling) and own education (low defined <college degree; includes some college) were reported by 1,633 participants. Intergenerational education was categorized as stable low (reference), low‐high, high‐low, and stable high. Cognitive domains were analyzed as a z‐score composite and as independent domains using linear mixed models adjusting for age, gender, race, and nativity; potential effect heterogeneity was evaluated as interactions between educational trajectories and (1) SENAS domains, (2) race/ethnicity, (3) gender.ResultsAll participants with high own education had higher average cognitive scores than those with low own education; those with low‐high trajectories had higher average cognitive scores (B̂=0.33; 95% CI: 0.23, 0.42) than those with stable high trajectories (B̂=0.19; 95% CI: 0.09, 0.29). Those with high‐low trajectories had lower average cognitive scores (B̂=‐0.16; 95% CI: ‐0.25, ‐0.07) than those with stable low trajectories. Effect sizes but not overall patterns differed by cognitive domain (p<.0001) and gender (p=0.0097); there was no evidence of effect heterogeneity by race (interaction P‐value=0.6691).ConclusionOwn education was associated with late‐life cognition across all levels of parental education. Effect estimates were largest for an upward trajectory of intergenerational education with similar patterns across cognitive domains. Education may open cognitively beneficial opportunities for individuals with low parental education indicating the importance of supporting college entry/completion, though this may reflect the selection process of individuals who complete college despite low parental education.