Lifecourse Social Conditions and Racial and Ethnic Patterns of Cognitive Aging

Sociodemographic Correlates of Cognition in the Multi-Ethnic Study of Atherosclerosis (MESA)

OBJECTIVE

To describe the methodology utilized to evaluate cognitive function in the Multi-Ethnic Study of Atherosclerosis (MESA) and to present preliminary results by age, sex, and race/ethnicity.

DESIGN

Cross-sectional measurements of a prospective observational cohort.

SETTING

Residents of 6 U.S. communities free of cardiovascular disease at baseline (2000-02).

PARTICIPANTS

4,591 adults who completed the fifth MESA clinical examination in 2011-12; mean age 70.3 (SD: 9.5) years, 53.1% women, 40.7% non-Hispanic white, 26.4% non-Hispanic black, 21.4% Hispanic, and 11.5% Chinese.

MEASUREMENTS

The cognitive battery consisted of the Cognitive Abilities Screening Instrument (version 2) to evaluate global cognition, the Digit Symbol Code for processing speed and Digit Spans Forward and Backward to assess memory. Demographic, socioeconomic, and cultural covariates were also collected for descriptive statistics and multivariate modeling.

RESULTS

Associations between socioeconomic factors and cognition revealed that age, race/ethnicity, education, occupational status, household income, health insurance type, household size, place of birth, years and generation in U.S., and the presence of the ApoE4 allele were significantly associated with performance on the cognitive tests, although patterns varied by specific test, racial/ethnicity, and sociocultural factors.

CONCLUSION

As many of the influencing cultural and socioeconomic factors measured here are complex, multifactorial, and may not be adequately quantified, caution has been recommended with regard to comparison and interpretation of racial/ethnic group performance differences from these cross-sectional models. These data provide a baseline for future exams and more comprehensive longitudinal analyses of the contributions of subclinical and clinical diseases to cognitive function and decline.

Historical Differences in School Term Length and Measured Blood Pressure: Contributions to Persistent Racial Disparities among US-Born Adults

INTRODUCTION

Legally mandated segregation policies dictated significant differences in the educational experiences of black and white Americans through the first half of the 20th century, with markedly lower quality in schools attended by black children. We determined whether school term length, a common marker of school quality, was associated with blood pressure and hypertension among a cohort of older Americans who attended school during the de jure segregation era.

METHODS

National Health and Nutrition Examination Survey I and II data were linked to state level historical information on school term length. We used race and gender-stratified linear regression models adjusted for age, state and year of birth to estimate effects of term length on systolic and diastolic blood pressure (SBP and DBP) and hypertension for US-born adults. We also tested whether correcting years of schooling for term length differences attenuated estimated racial disparities.

RESULTS

Among black women, 10% longer school term was associated with lower SBP, DBP and hypertension prevalence (2.1 mmHg, 1.0 mmHg, and 5.0 percentage points respectively). Associations for whites and for black men were not statistically significant. Adjustment for education incorporating corrections for differences in school term length slightly attenuated estimated racial disparities.

CONCLUSIONS

Longer school term length predicted better BP outcomes among black women, but not black men or whites.

RBANS Norms based on the Relationship of Age, Gender, Education, and WRAT-3 Reading to Performance within an Older African American Sample

OBJECTIVE

Due to factors including differences in educational opportunity, African Americans and Caucasians frequently differ on cognitive tests creating diagnostic error risks. Such differences have been found on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and preliminary norms based on a small sample of African Americans have been generated. In a larger sample of community-dwelling older African Americans, we explored sources of variance including age, gender, common medical conditions, years of education, and reading level to generate norms stratified on the most relevant bases.

METHOD

Three hundred and fifty-five African Americans aged 55+ and living independently completed the RBANS and health, education, and psychosocial interviews.

RESULTS

Hypertension and type 2 diabetes were unrelated to overall RBANS performance once age and education were accounted for. Age, education, and WRAT-3 Reading score (a proxy for scholastic attainment) were independent predictors of RBANS performance. Females performed better on List Learning, Story Memory, Fluency, Coding, List Recall, and List Recognition; males were superior on Line Orientation and Picture Naming.

CONCLUSIONS

In addition to generating norms stratified by age, we provide descriptive statistics grouped by age and education, and by age and WRAT-3 Reading grade level, to provide clinicians with the opportunity to tailor their interpretation of scores based upon perceived best fit for their patient. Regression formulas are provided to address gender differences. To complement the standard index norms, we provide norms for alternative indexes representing additional an factor structure of cognitive domains.

The association between community environment and cognitive function: a systematic review

PURPOSES

The aim of this study is to review the published evidence on the association between community environment and cognitive function in older people, focusing on the findings and a critique of the existing studies.

METHODS

A literature search was conducted to identify studies linking the community environment and cognitive function in older people. The results and methodological factors, including the definition of community, individual level characteristics and the measurements of cognitive function and community environment were extracted from each study. The measurements of community environment were mainly categorized into two types: compositional, generated by aggregating individual and household data (community-level socioeconomic status, deprivation index) and contextual, targeting at the features of built or social environment in local areas (green space, street conditions, crime rate).

RESULTS

Fourteen of the fifteen studies used compositional measurements such as community-level socioeconomic status and deprivation index and significant associations were found in eleven studies. Some individual level factors (ethnicity, genotype and socioeconomic status) were found to modify the association between community environment and cognitive function. Few contextual measurements were included in the existing studies. A conceptual framework for the pathway from community environment to cognitive function of older people is provided in this review.

CONCLUSIONS

To disentangle the additional effect of place from individual risk factors and investigate the casual direction of community environment and cognition in later life, longitudinal studies with measurements targeting built and social environments of community and change of cognitive functions over time need to be included in future studies.

Type 2 diabetes and cognitive decline over 14 years in middle-aged African Americans and whites: the ARIC Brain MRI Study

BACKGROUND

Diabetes predicts late-life dementia, but the association with rate of cognitive decline is inconsistent and has rarely been examined in non-white populations, despite the high prevalence of diabetes in African Americans. We evaluated the effect of diabetes on cognitive decline in middle-aged African Americans and whites.

METHODS

Atherosclerosis Risk in Communities (ARIC) Brain MRI Study participants (n = 1,886, mean age = 60, 49% African American) underwent assessments of verbal memory, processing speed, and verbal fluency four times over 14 years. Using race-stratified mixed linear effects models, we examined cognitive change for participants with prevalent (baseline) diabetes and incident (diagnosed after baseline) diabetes versus those without diabetes.

RESULTS

African Americans had more advanced diabetes, as indicated by fasting blood glucose levels, anti-diabetes medication use, and cardiovascular risk profiles. African Americans with prevalent diabetes experienced 41% greater annual decline in processing speed scores (p = 0.048) and 50% greater annual decline in verbal fluency scores (p = 0.042) than those without diabetes; incident diabetes was not associated with cognitive decline. Among whites, diabetes was not associated with cognitive decline.

CONCLUSIONS

Prevalent diabetes was associated with greater cognitive decline in middle-aged African Americans, possibly reflecting adverse effects of longer duration and more advanced diabetes.

Life experience and demographic influences on cognitive function in older adults

OBJECTIVE

We examined the influence of a broad spectrum of life experiences on longitudinal cognitive trajectories in a demographically diverse sample of older adults.

METHOD

Participants were 333 educationally, ethnically, and cognitively diverse older adults enrolled in a longitudinal aging study. Mixed-effects regression was used to measure baseline status in episodic memory, executive functioning, and semantic memory and change in a global cognition factor defined by change in these 3 domain-specific measures. We examined effects of life experience variables (literacy, childhood socioeconomic status, morphometric measures of physical development, life course physical and recreational activity) on longitudinal cognitive trajectories, covarying for age, apolipoprotein E (APOE) genotype and demographics (education, ethnicity, language).

RESULTS

Non-Latino Whites had higher baseline cognition, but life experience variables attenuated ethnic differences in cognitive scores. Age, literacy, childhood socioeconomic status, and physical activity significantly influenced baseline cognition. Age, APOE ε4, and decline in intellectually and socially stimulating recreational activity from mid to late life were independently associated with increased late life cognitive decline. Higher literacy and late life recreational activity were associated with less decline. Literacy had similar effects for English and Spanish readers/speakers. Bilingual English and Spanish speakers did not differ from English Speakers in cognitive performance.

CONCLUSIONS

Life experience variables, especially literacy level, were strongly related to baseline cognition and substantially attenuated effects of race/ethnicity and education. Cognitive change was best explained by age, APOE ε4, literacy, and current recreational activities. Literacy had robust associations with baseline cognition and cognitive change in both English and Spanish speakers.

Maternal education, anthropometric markers of malnutrition and cognitive function (ELSA-Brasil)

Background

The early exposure to poor social and nutritional conditions may influence cognitive function during adult age. However, the relative impact of these factors has not yet been established and they can vary during the course of life.

Methods

Analysis of data from 12,997 participants (35-64 years) of the baseline exams (2008-2010) of the Longitudinal Study of Adult Health (ELSA-Brasil), a cohort of Brazilian civil servants. Four cognitive tests were applied: learning, recall and word recognition; semantic and phonemic verbal fluency; trail-making test version B. The markers of early nutritional and social conditions were maternal educational level, birth weight, and length of trunk and leg. The presence of independent association between every early marker and the poor performance in each cognitive test was investigated by multiple logistic regression, after mutual adjustment and considering the effects of gender, age and participant’s schooling level. The cut off for poor performance was the worst age-specific percentile of the final score distribution for each test.

Results

After full adjustments, lower maternal education increased the chances of poor performance in all cognitive tests, with a dose-response gradient; low birth-weight was related to poor performance in the trail-making test B (OR = 1.63, 95% IC = 1.29-2.06); and greater trunk length decreased the chances of poor performance in the semantic and phonemic verbal fluency (OR = 0.96, 95% IC = 0.94-0.97) and in the trail-making test B (OR = 0.94, 95% IC = 0.92-0.95). Leg length was not associated with any of the tests examined. The associations found were not modified by the educational attainment of the participants.

Conclusions

Early exposure to adverse social and nutritional conditions appear detrimental to semantic memory, learning, concentration, executive control and language among adults, independent of adulthood educational achievement.

Veteran Status and Men’s Later-Life Cognitive Trajectories

Objective: The aim of this study is to determine the extent to which men’s later-life cognitive trajectories vary by veteran status. Method: We use Health and Retirement Study (HRS) data to estimate growth curve models examining men’s later-life cognitive trajectories by veteran status, war service status, and period of service. Analyses control for early-life characteristics that influence selection into military service and later-life cognition, and mid- to late-life characteristics that potentially mediate the relationship between military service and later-life cognition. Results: Veterans have higher cognition scores relative to nonveterans around retirement age, but their cognition scores decline more rapidly with increasing age, such that cognition scores are similar in both groups among the oldest old. Veterans who served during the Korean War have lower cognition scores around retirement age, but less steep age-related declines, than veterans who served during World War II. Discussion: Findings are discussed in relation to the extant literature, future research, potential service needs, and study limitations.

Changes in memory before and after stroke differ by age and sex, but not by race

BACKGROUND

Post-stroke memory impairment is more common among older adults, women and blacks. It is unclear whether post-stroke differences reflect differential effects of stroke per se or differences in prestroke functioning. We compare memory trajectories before and after stroke by age, sex and race.

METHODS

Health and Retirement Study participants aged ≥50 years (n = 17,341), with no stroke history at baseline, were interviewed biennially up to 10 years for first self- or proxy-reported stroke (n = 1,574). Segmented linear regression models were used to compare annual rates of memory change before and after stroke among 1,169 stroke survivors, 405 stroke decedents and 15,767 stroke-free participants. Effect modification was evaluated with analyses stratified by baseline age (≤70 vs. >70), sex and race (white vs. nonwhite), and using interaction terms between age/sex/race indicators and annual memory change.

RESULTS

Older (>70 years) adults experienced a faster memory decline before stroke (-0.19 vs. -0.10 points/year for survivors, -0.24 vs. -0.13 points/year for decedents, p < 0.001 for both interactions), and among stroke survivors, larger memory decrements (-0.64 vs. -0.26 points, p < 0.001) at stroke and faster memory decline (-0.15 vs. -0.07 points/year, p = 0.003) after stroke onset, compared to younger adults. Female stroke survivors experienced a faster prestroke memory decline than male stroke survivors (-0.14 vs. -0.10 points/year, p < 0.001). However, no sex differences were seen for other contrasts. Although whites had higher post-stroke memory scores than nonwhites, race was not associated with rate of memory decline during any period of time; i.e. race did not significantly modify the rate of decline before or after stroke or the immediate effect of stroke on memory.

CONCLUSIONS

Older age predicted worse memory change before, at and after stroke onset. Sex and race differences in post-stroke memory outcomes might be attributable to prestroke disparities, which may be unrelated to cerebrovascular disease.

Early life development in a multiethnic sample and the relation to late life cognition

OBJECTIVES

Poor quality of early life conditions has been associated with poorer late life cognition and increased risk of dementia. Early life physical development can be captured using adult measures of height and head circumference. Availability of resources may be reflected by socioeconomic indicators, such as parental education and family size. We sought to determine the association between early life development and experience and late life semantic memory, episodic memory, and executive functioning abilities, as well as rate of cognitive decline.

METHOD

This study was conducted using the UC Davis Aging Diversity cohort, an ethnically diverse sample of Caucasian, African American, and Hispanic individuals from northern California. We used latent variable modeling to measure growth and childhood socioeconomic environment (SES) and examine their associations with longitudinal cognitive outcomes using mixed effects modeling.

RESULTS

Growth was positively related to higher childhood SES. Higher childhood SES was associated with better semantic memory. Both low growth and low SES were associated with increased rate of cognitive decline.

DISCUSSION

These findings demonstrate that early life experiences influence the trajectory of cognitive aging. Early life development and experience appears to provide a distal basis upon which additional risk and protective factors interact in the development of dementia.

The association between health literacy and indicators of cognitive impairment in a diverse sample of primary care patients

OBJECTIVES

To confirm the association of health literacy scores as measured by Health Literacy Assessment Using Talking Touchscreen Technology (Health LiTT) with cognitive ability and education. To determine whether this association differs by cognitive task.

METHODS

Cognitive impairment was measured using the Mini-Cog, which combines a delayed word recall task (WRT) and a clock drawing task (CDT) to yield an overall classification of normal versus cognitively impaired. Participants were recruited from primary care clinics that provide care to underserved patients.

RESULTS

Participants (n=574) were predominantly non-Hispanic black (67%) with a mean age of 46 years, 50% did not have health insurance, 56% had a high school education or less and 21% screened positive for cognitive impairment. Overall cognitive ability and education were significantly associated with health literacy after adjusting for other variables, including race/ethnicity and physical health. We observed a stronger association between the CDT and health literacy than between the WRT and health literacy.

CONCLUSION

By confirming hypothesized associations, this study provides additional support of the validity of Health LiTT.

PRACTICE IMPLICATIONS

Health LiTT is a reliable and valid tool that researchers and clinicians can use to identify individuals who might have difficulty understanding health information.

The embodied and relational nature of the mind: implications for clinical interventions in aging individuals and populations

Considerable research over the past decade has garnered support for the notion that the mind is both embodied and relational. Jointly, these terms imply that the brain, physical attributes of the self, and features of our interpersonal relationships and of the environments in which we live jointly regulate energy and information flow; they codetermine how we think, feel, and behave both individually and collectively. In addition to direct experience, evidence supports the view that stimuli embedded within past memories trigger multimodal simulations throughout the body and brain to literally recreate lived experience. In this paper, we review empirical support for the concept of an embodied and relational mind and then reflect on the implications of this perspective for clinical interventions in aging individuals and populations. Data suggest that environmental influences literally “get under the skin” with aging; that musculoskeletal and visceral sensations become more prominent in activities of the mind due to aging biological systems and chronic disease. We argue that conceiving the mind as embodied and relational will grow scientific inquiry in aging, transform how we think about the self-system and well-being, and lead us to rethink health promotion interventions aimed at aging individuals and populations.

Coordinated analysis of age, sex, and education effects on change in MMSE scores

OBJECTIVES

We describe and compare the expected performance trajectories of older adults on the Mini-Mental Status Examination (MMSE) across six independent studies from four countries in the context of a collaborative network of longitudinal studies of aging. A coordinated analysis approach is used to compare patterns of change conditional on sample composition differences related to age, sex, and education. Such coordination accelerates evaluation of particular hypotheses. In particular, we focus on the effect of educational attainment on cognitive decline.

METHOD

Regular and Tobit mixed models were fit to MMSE scores from each study separately. The effects of age, sex, and education were examined based on more than one centering point.

RESULTS

Findings were relatively consistent across studies. On average, MMSE scores were lower for older individuals and declined over time. Education predicted MMSE score, but, with two exceptions, was not associated with decline in MMSE over time.

CONCLUSION

A straightforward association between educational attainment and rate of cognitive decline was not supported. Thoughtful consideration is needed when synthesizing evidence across studies, as methodologies adopted and sample characteristics, such as educational attainment, invariably differ.

Latent heterogeneity in long-term trajectories of body mass index in older adults

OBJECTIVE

To evaluate latent heterogeneity in long-term trajectories of body weight in older adults.

METHODS

We analyzed 14-year longitudinal data on 10,314 older adults from the Health and Retirement Study. Semiparametric mixture models identified latent subgroups of similar trajectories of body mass index (BMI).

RESULTS

Five distinct trajectory subgroups emerged: normal starting-BMI with accelerated increase over time (trajectory #1), overweight and increasing (trajectory #2), borderline-obese and increasing (trajectory #3), obese and increasing (trajectory #4), and morbidly obese with decelerating gain (trajectory #5). Blacks and Hispanics had greater risk of membership in ascending high-BMI trajectory groups. Females had approximately half the risk of following overweight and obese increasing BMI trajectories compared with males.

DISCUSSION

Distinct latent subgroups of BMI trajectories and significant racial/ethnic and gender trajectory heterogeneity exist in the older adult population. The propensity of men and minorities to experience high-risk BMI trajectories may exacerbate existing disparities in morbidity/ mortality in older age.

Demographic predictors of cognitive change in ethnically diverse older persons

The purpose of this study was to evaluate how demographic variables relate to cognitive change and address whether cross-sectional demographic effects on cognitive tests are mirrored in differences in longitudinal trajectories of cognitive decline. We hypothesized that race and ethnicity, education, and language of test administration would relate to cross-sectional status and that the rate of cognitive decline would differ among African Americans, Hispanics, and Caucasians, across levels of educational attainment, and according to linguistic background. Participants were 404 educationally, ethnically, and cognitively diverse older adults enrolled in an ongoing longitudinal study of cognition. Mixed-effects regression analysis was used to measure baseline status and longitudinal change in episodic memory, executive functioning, and semantic memory. Results showed that ethnicity and education were strongly associated with baseline scores, but were, at most, weakly associated with change in cognition over time after accounting for confounding variables. There was evidence that the episodic-memory scores of Spanish-speaking Hispanic participants with limited education underestimated their true abilities in the initial evaluation, which may reflect lack of familiarity with the testing environment. These results--consistent with other reports in the literature--suggest that cross-sectional effects of demographic variables on cognitive-test scores result from differences in life experiences that directly influence test performance and do not indicate greater disease effects on cognition in minorities and those with limited education.

Effects of early-life adversity on cognitive decline in older African Americans and whites

OBJECTIVES

Early-life adversity is related to adult health in old age but little is known about its relation with cognitive decline.

METHODS

Participants included more than 6,100 older residents (mean age = 74.9 [7.1] years; 61.8% African American) enrolled in the Chicago Health and Aging Project, a geographically defined, population-based study of risk factors for Alzheimer disease. Participants were interviewed at approximately 3-year intervals for up to 16 years. The interview included a baseline evaluation of early-life adversity, and administration of 4 brief cognitive function tests to assess change in cognitive function. We estimated the relation of early-life adversity to rate of cognitive decline in a series of mixed-effects models.

RESULTS

In models stratified by race, and adjusted for age and sex, early-life adversity was differentially related to decline in African Americans and whites. Whereas no measure of early-life adversity related to cognitive decline in whites, both food deprivation and being thinner than average in early life were associated with a slower rate of cognitive decline in African Americans. The relations were not mediated by years of education and persisted after adjustment for cardiovascular factors.

CONCLUSIONS

Markers of early-life adversity had an unexpected protective effect on cognitive decline in African Americans.

Early life predictors of atrial fibrillation-related mortality: evidence from the health and retirement study

Prior research found that Americans born in 6 southeastern states (the AF-risk zone) had elevated risk of AF-related mortality, but no mechanisms were identified. We hypothesized the association between AF-related mortality and AF-risk zone birth is explained by indicators of childhood social disadvantage or adult risk factors. In 24,323 participants in the US Health and Retirement Study, we found that birth in the AF-risk zone was significantly associated with hazard of AF-related mortality. Among whites, the relationship was specific to place of birth, rather than place of adult residence. Neither paternal education nor subjectively assessed childhood SES predicted AF-related mortality. Conventional childhood and adult cardiovascular risk factors did not explain the association between place of birth and AF-related mortality.

Cognitive decline and cardiometabolic risk among Hispanic and non-Hispanic white adults in the San Luis Valley Health and Aging Study

Cardiometabolic risk factors, including hypertension, dyslipidemia, central obesity, insulin resistance and diabetes are linked to cognitive impairment. The Hispanic population appears to be differentially affected by both cardiometabolic risk factors and cognitive impairment. We sought to determine whether ethnic differences in cognitive impairment in long-resident southwestern US elders was explained by the presence of cardiometabolic risk factors, and to explore patterns of cognitive decline over time. We performed a secondary analysis of data collected on 378 Hispanic and 409 non-Hispanic white adult participants in a longitudinal study of community-dwelling elderly in southern Colorado. Measures of cardiometabolic risk included waist circumference, blood pressure, diagnosis of diabetes, and random blood glucose. Cognitive measures included the Mini-Mental State Exam (MMSE) and the behavioral dyscontrol scale (a measure of executive cognitive function), at baseline and after an average of 22 months. Subjects were also administered the Center for Epidemiologic Studies Depression Scale, and the Coronary Artery Risk Development in Young Adults 1-Year Activity Recall. At baseline, Hispanic elders had a greater number of cardiometabolic risk factors and lower MMSE and behavioral dyscontrol scale scores than non-Hispanic whites. Hispanic ethnicity was associated with a greater likelihood of decline in general cognitive function, but not executive cognitive function, after adjusting for age and education. This differential decline was not explained by either individual or total number of baseline cardiometabolic risk factors, depression, or physical activity. A borderline increased risk of decline in general cognitive function was seen in sedentary individuals (P = 0.05).

Perceived discrimination and cognition in older African Americans

Existing evidence suggests that psychosocial stress is associated with cognitive impairment in older adults. Perceived discrimination is a persistent stressor in African Americans that has been associated with several adverse mental and physical health outcomes. To our knowledge, the association of discrimination with cognition in older African Americans has not been examined. In a cohort of 407 older African Americans without dementia (mean age = 72.9; SD = 6.4), we found that a higher level of perceived discrimination was related to poorer cognitive test performance, particularly episodic memory (estimate = -0.03; SE = .013; p < .05) and perceptual speed tests (estimate = -0.04; SE = .015; p < .05). The associations were unchanged after adjusting for demographics and vascular risk factors, but were attenuated after adjustment for depressive symptoms (Episodic memory estimate = -0.02; SE = 0.01; Perceptual speed estimate = -0.03; SE = 0.02; both p's = .06). The association between discrimination and several cognitive domains was modified by level of neuroticism. The results suggest that perceived discrimination may be associated with poorer cognitive function, but does not appear to be independent of depressive symptoms. (JINS, 2012, 18, 1-10).

Theory-guided selection of discrimination measures for racial/ ethnic health disparities research among older adults

OBJECTIVE

Discrimination may contribute to health disparities among older adults. Existing measures of perceived discrimination have provided important insights but may have limitations when used in studies of older adults. This article illustrates the process of assessing the appropriateness of existing measures for theory-based research on perceived discrimination and health.

METHOD

First, we describe three theoretical frameworks that are relevant to the study of perceived discrimination and health-stress-process models, life course models, and the Public Health Critical Race (PHCR) praxis. We then review four widely-used measures of discrimination, comparing their content and describing how well they address key aspects of each framework, and discussing potential areas of modification.

DISCUSSION

Using theory to guide measure selection can help improve understanding of how perceived discrimination may contribute to racial/ethnic health disparities among older adults.

Transition to retirement and risk of cardiovascular disease: prospective analysis of the US health and retirement study

Transitioning from work to retirement could be either beneficial or harmful for health. We investigated the association between transition to retirement and risk of stroke and myocardial infarction (MI). We followed US Health and Retirement Study participants age 50+ working full-time for pay and free of major cardiovascular disease (n = 5422) in 1998 up to 10 years for transition to full retirement and self- or proxy-report of either stroke or MI (CVD; 665 events). We used discrete-time survival analysis to compare the CVD incidence for the fully retired versus the full-time working population. To distinguish short-term from long-term risks, we compared the association in the first year after retirement to estimates 2+ years after retirement. In the full model adjusting for age, sex, childhood and adult SES, behavior, and co-morbidities, being retired was associated with elevated odds of CVD onset (OR = 1.40, 95% CI: 1.04, 1.90) compared to those remaining in the full-time labor force. The odds ratio for CVD incidence within the first year of retirement was 1.55 (95% CI: 1.03, 2.33). From the second year post-retirement and thereafter, the retired had marginally elevated risk of CVD compared to those still working (OR = 1.35; 95% CI: 0.96, 1.91). Although confidence intervals were wide for some sub-groups, there were no significant interactions by sex or socioeconomic status. Results suggest that CVD risk is increased after retirement.

Immigrant status and cognitive functioning in late-life: an examination of gender variations in the healthy immigrant effect

Although some research suggests that the healthy immigrant effect extends to cognitive functioning, it is unclear whether this general pattern varies according to gender. We use six waves of data collected from the original cohort of the Hispanic Established Populations for the Epidemiologic Study of the Elderly to estimate a series of linear growth curve models to assess variations in cognitive functioning trajectories by nativity status and age at migration to the U.S.A. among women and men. Our results show, among women and men, no differences in baseline cognitive status (intercepts) between early- (before age 20) and late-life (50 and older) immigrants and U.S.-born individuals of Mexican-origin. We also find, among women and men, that middle-life (between the ages of 20 and 49) immigrants tend to exhibit higher levels of baseline cognitive functioning than the U.S.-born. Our growth curve analyses suggest that the cognitive functioning trajectories (slopes) of women do not vary according to nativity status and age at migration. The cognitive functioning trajectories of early- and late-life immigrant men are also similar to those of U.S.-born men; however, those men who migrated in middle-life tend to exhibit slower rates of cognitive decline. A statistically significant interaction term suggests that the pattern for middle-life migration is more pronounced for men (or attenuated for women). In other words, although women and men who migrated in middle-life exhibit higher levels of baseline cognitive functioning, immigrant men tend to maintain this advantage for a longer period of time. Taken together, these patterns confirm that gender is an important conditioning factor in the association between immigrant status and cognitive functioning.

Indicators of childhood quality of education in relation to cognitive function in older adulthood

BACKGROUND

The association between years of education and cognitive function in older adults has been studied extensively, but the role of quality of education is unknown. We examined indicators of childhood educational quality as predictors of cognitive performance and decline in later life.

METHODS

Participants included 433 older adults (52% African American) who reported living in Alabama during childhood and completed in-home assessments of cognitive function at baseline and 4 years later. Reports of residence during school years were matched to county-level data from the 1935 Alabama Department of Education report for school funding (per student), student-teacher ratio, and school year length. A composite measure of global cognitive function was utilized in analyses. Multilevel mixed effects models accounted for clustering of educational data within counties in examining the association between cognitive function and the educational quality indices.

RESULTS

Higher student-teacher ratio was associated with worse cognitive function and greater school year length was associated with better cognitive function. These associations remained statistically significant in models adjusted for education level, age, race, gender, income, reading ability, vascular risk factors, and health behaviors. The observed associations were stronger in those with lower levels of education (≤12 years), but none of the education quality measures were related to 4-year change in cognitive function.

CONCLUSIONS

Educational factors other than years of schooling may influence cognitive performance in later life. Understanding the role of education in cognitive aging has substantial implications for prevention efforts as well as accurate identification of older adults with cognitive impairment.

Stroke incidence in older US Hispanics: is foreign birth protective?

BACKGROUND AND PURPOSE

Although Hispanics are the fastest growing ethnic group in the United States, relatively little is known about stroke risk in US Hispanics. We compare stroke incidence and socioeconomic predictors in US- and foreign-born Hispanics with patterns among non-Hispanic whites.

METHODS

Health and Retirement Study participants aged 50+ years free of stroke in 1998 (mean baseline age, 66.3 years) were followed through 2008 for self- or proxy-reported first stroke (n=15 784; 1388 events). We used discrete-time survival analysis to compare stroke incidence among US-born (including those who immigrated before age 7 years) and foreign-born Hispanics with incidence in non-Hispanic whites. We also examined childhood and adult socioeconomic characteristics as predictors of stroke among Hispanics, comparing effect estimates with those for non-Hispanic whites.

RESULTS

In age- and sex-adjusted models, US-born Hispanics had higher odds of stroke onset than non-Hispanic whites (OR, 1.44; 95% CI, 1.08-1.90), but these differences were attenuated and nonsignificant in models that controlled for childhood and adulthood socioeconomic factors (OR, 1.07; 95% CI, 0.80-1.42). In contrast, in models adjusted for all demographic and socioeconomic factors, foreign-born Hispanics had significantly lower stroke risk than non-Hispanic whites (OR, 0.58; 95% CI, 0.41-0.81). The impact of socioeconomic predictors on stroke did not differ between Hispanics and whites.

CONCLUSIONS

In this longitudinal national cohort, foreign-born Hispanics had lower incidence of stroke incidence than non-Hispanic whites and US-born Hispanics. Findings suggest that foreign-born Hispanics may have a risk factor profile that protects them from stroke as compared with other Americans.

Life-course exposure to early socioeconomic environment, education in relation to late-life cognitive function among older Mexicans and Mexican Americans

OBJECTIVES

To examine the associations between life-course education and late-life cognitive function along with the modifying role of migration history.

METHOD

The combined sample includes 1,789 participants from the Sacramento Area Latino Study on Aging and 5,253 participants from the Mexican Health and Aging Study. Aged 60+ at baseline, participants were classified as Mexican residents, Mexicans-return migrants, Mexicans-immigrants to the United States, and Mexicans-U.S. born. Cognitive function was measured using standardized z scores of a short-term verbal recall test. Multivariate linear regression analysis was conducted.

RESULTS

Participants' z scores were higher among those whose mother had more than elementary education (β = 0.28, p < .05). Participant's education mediated this association. For 5-year difference in education, the cognitive z score increased by 0.3 points for a U.S. born. Results were similar with father's education.

DISCUSSION

Adult educational attainment mediates the effect of childhood socioeconomic status on late-life cognition. Migration plays a role in shaping cognitive aging.

Early-life antecedents of atrial fibrillation: place of birth and atrial fibrillation-related mortality

PURPOSE

Recent evidence suggests early-life factors correlate with atrial fibrillation (AF). We hypothesized that AF-related mortality, similar to stroke mortality, is elevated for individuals born in the southeastern United States.

METHODS

We estimated 3-year (1999-2001) average AF-related mortality rates by using U.S. vital statistics for 55- to 89-year-old white (136,573 AF-related deaths) and black subjects (8,288 AF-related deaths). We estimated age- and sex-adjusted odds of AF-related (contributing cause) mortality associated with birth state, and birth within the U.S. stroke belt (SB), stratified by race. SB results were replicated with the use of 1989-1991 data.

RESULTS

Among black subjects, four contiguous birth states were associated with statistically significant odds ratios ≥ 1.25 compared with the national average AF-related mortality. The four highest-risk birth states for blacks also predicted elevated AF-related mortality among white subjects, but patterns were attenuated. The odds ratio for AF-related mortality associated with SB birth was 1.19 (confidence interval 1.13-1.25) for black and 1.09 (CI 1.07-1.12) for white subjects when we adjusted for SB adult residence.

CONCLUSIONS

Place of birth predicted AF-related mortality, after we adjusted for place of adult residence. The association of AF-related mortality and SB birth parallels that of other cardiovascular diseases and may likewise indicate an importance of early life factors in the development of AF.

A life course approach to the development of mental skills

A wide variety of factors across the life course jointly influence cognitive and emotional development. Indeed, research from a variety of disciplines strongly suggests that cognition and mental health are intertwined across the life course, by their common antecedents and underlying physiology in development and in their interplay across adult and later life. We suggest that cognitive and socioemotional function fuse to form skills for life supporting self-regulation, competence, and quality of life that persist into later life through linked reciprocal processes of genetic influence, nurturing, schooling, work, and lifestyle.

Racial/ethnic residential segregation: framing the context of health risk and health disparities

An increasing body of public health literature links patterns of racial/ethnic residential segregation to health status and health disparities. Despite substantial new empirical work, meaningful understanding of the pathways through which segregation operates to influence health remains elusive. The literature on segregation and health was appraised with an emphasis on select conceptual, methodological, and analytical issues. Recommendations for advancing the next generation of racial/ethnic residential segregation and health research will require closer attention to sharpening the methodology of measuring segregation, testing mediating pathways and effect modification, incorporating stronger test of causality, exploring factors of resilience in segregated areas, applying a life-course perspective, broadening the scope of the investigation of segregation to include nativity status in blacks and other racial/ethnic groups, and linking segregation measures with biological data.

Higher education delays and shortens cognitive impairment: a multistate life table analysis of the US Health and Retirement Study

Improved health may extend or shorten the duration of cognitive impairment by postponing incidence or death. We assess the duration of cognitive impairment in the US Health and Retirement Study (1992–2004) by self reported BMI, smoking and levels of education in men and women and three ethnic groups. We define multistate life tables by the transition rates to cognitive impairment, recovery and death and estimate Cox proportional hazard ratios for the studied determinants. 95% confidence intervals are obtained by bootstrapping. 55 year old white men and women expect to live 25.4 and 30.0 years, of which 1.7 [95% confidence intervals 1.5; 1.9] years and 2.7 [2.4; 2.9] years with cognitive impairment. Both black men and women live 3.7 [2.9; 4.5] years longer with cognitive impairment than whites, Hispanic men and women 3.2 [1.9; 4.6] and 5.8 [4.2; 7.5] years. BMI makes no difference. Smoking decreases the duration of cognitive impairment with 0.8 [0.4; 1.3] years by high mortality. Highly educated men and women live longer, but 1.6 years [1.1; 2.2] and 1.9 years [1.6; 2.6] shorter with cognitive impairment than lowly educated men and women. The effect of education is more pronounced among ethnic minorities. Higher life expectancy goes together with a longer period of cognitive impairment, but not for higher levels of education: that extends life in good cognitive health but shortens the period of cognitive impairment. The increased duration of cognitive impairment in minority ethnic groups needs further study, also in Europe.

Implications of Lifecourse Epidemiology for Research on Determinants of Adult Disease

Many diseases commonly associated with aging are now thought to have social and physiologic antecedents in early life. Understanding how the timing of exposure to early life risk factors influences later-life health may illuminate mechanisms driving adult health inequalities and identify possible points for effective interventions. Recognizing chronic diseases as developing across the lifecourse also has implications for the conduct of research on adult risk factors for disease. We review alternative conceptual models that describe how the timing of risk factor exposure relates to the development of disease. We propose some expansions of lifecourse models to improve their relevance for research on adult chronic disease, using the relationship between education and adult cognitive decline and dementia as an example. We discuss the important implications each of the lifecourse conceptual models has on study design, analysis, and interpretation of research on aging and chronic diseases. We summarize several research considerations implied by the lifecourse framework, including: advantages of analyzing change in function rather than onset of impairment; the pervasive challenge of survivor bias; the importance of controlling for possible confounding by early life conditions; and the likely heterogeneity in responses of adults to treatment.