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

Health insurance coverage moderates the relationship between metabolic syndrome and baseline memory outcomes in Latino older adults

Objective: Latino adults are at increased risk of metabolic syndrome (MetS) and have lower rates of health insurance (HI) coverage. Although inadequate HI coverage and MetS have been independently linked to poor cognition, their potential interactive effects have not yet been examined. The present study explored whether HI moderated the association between MetS and cognition. We hypothesized that Latinos with MetS that did not have HI would demonstrate poorer cognition than those with HI, whereas there would be minimal differences in cognition across HI status in those without MetS. Methods: Cross-sectional data from 805 Latino older adults enrolled in the Health and Aging Brain Study-Health Disparities was utilized. Analysis of covariance adjusting for sociodemographics examined MetS x HI interactions on memory and attention/executive functions composites. Results: Results revealed a significant MetS x HI interaction on memory (F = 4.33, p = 0.037, ηp2 = .01); Latino adults with MetS and no HI coverage had worse memory performance than those with MetS who had HI coverage (p = 0.022, ηp2 = .01), whereas there was no significant difference in memory between HI coverage groups in those without MetS (p > .05, ηp2 = .002). No MetS x HI interaction was observed for the attention/executive functions composite (F = 0.29, p = 0.588, ηp2 < .001). Conclusion: Latino older adults with MetS that do not have HI coverage may be at risk for poorer memory outcomes. Increasing the accessibility of HI coverage may help reduce cognitive health disparities in Latino older adults with vascular health comorbidities.

The Association of Mitral Annular Calcification With Cardiovascular and Noncardiovascular Outcomes: The Multi-Ethnic Study of Atherosclerosis

Mitral annular calcification (MAC) may be a potential marker of biologic aging. However, the association of MAC with noncardiovascular measures, including bone mineral density (BMD), incident renal failure, dementia, and noncardiovascular mortality, is not well-studied in a multiracial cohort. We used data from 6,814 participants (mean age: 62.2 ± 10.2 years, 52.9% women) without cardiovascular disease at baseline in the Multi-Ethnic Study of Atherosclerosis. MAC was assessed with noncontrast cardiac computed tomography at study baseline. Using multivariable-adjusted linear and logistic regression, we assessed the cross-sectional association of MAC with BMD and walking pace. Furthermore, using Cox proportional hazards, we evaluated the association of MAC with incident renal failure, dementia, and all-cause mortality. In addition, we assessed the association of MAC with cardiovascular and noncardiovascular mortality using competing risks regression. The prevalence of MAC was 9.5% and was higher in women (10.7%) than in men (8.0%). MAC was associated with low BMD (coefficient -0.04, 95% confidence interval [CI] -0.06 to -0.02), with significant interaction by gender (p-interaction = 0.035). MAC was, however, not associated with impaired walking pace (odds ratio 1.09, 95% CI 0.89 to 1.33). Compared with participants without MAC, those with MAC had an increased risk of incident renal failure, albeit nonsignificant (hazard ratio [HR] 1.18, 95% CI 0.95 to 1.45), and a significantly higher hazards of dementia (HR 1.36, 95% CI 1.10 to 1.70). In addition, participants with MAC had a substantially higher risk of all-cause (HR 1.47, 95% CI 1.29 to 1.69), cardiovascular (subdistribution HR 1.39, 95% CI 1.04 to 1.87), and noncardiovascular mortality (subdistribution HR 1.35, 95% CI 1.14 to 1.60) than those without MAC. MAC ≥100 versus <100 was significantly associated with reduced BMD, incident renal failure, dementia, all-cause, cardiovascular, and noncardiovascular mortality. In conclusion, MAC was associated with reduced BMD and dementia and all-cause, cardiovascular, and noncardiovascular mortality in this multiracial cohort. Thus, MAC may be a marker not only for atherosclerotic burden but also for other metabolic and inflammatory factors that increase the risk of noncardiovascular outcomes and death from other causes.

Association of Cardiovascular Fibrosis, Remodeling, and Dysfunction With Frailty, Prefrailty, and Functional Performance: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Cardiovascular disease is associated with higher incidence of frailty. However, the nature of the mechanisms underlying this association remains unclear. The purpose of this study is to identify cardiovascular phenotypes most associated with physical frailty and functional performance in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

As part of the MESA study, 3 045 participants underwent cardiovascular magnetic resonance and computed tomography between 2010 and 2012. Of these, 1 743 completed a Six-Minute Walk test (6MWT) and questionnaires (follow-up exam: 2016-2018) which were used to generate a binary combined frail/prefrail versus robust score according to a modified FRAIL Scale (self-report questionnaire). Multivariable logistic (binary frail outcome) or linear (6MWT) regression assessed the association between frailty and cardiovascular structure and function, aortic stiffness, coronary artery calcium, and myocardial fibrosis (ECV, extracellular volume fraction).

RESULTS

Participants were 66 ± 8 years, 52% female at the time of imaging, and 29.4% were classified as frail or prefrail. Older age and female gender were associated with greater odds of being in the frail/prefrail group. Concentric left ventricular remodeling (odds ratio [OR] 1.89, p = .008; Coef. -52.9, p < .001), increased ECV (OR 1.10, p = .002; Coef. -4.0, p = .001), and worsening left atrial strain rate at early diastole (OR 1.56, p ≤ .001; Coef. -22.75, p = .027) were found to be associated with a greater likelihood of being in a frail state and lower 6MWT distance (m). All associations with 6MWT performance were attenuated with adjustments for risk factors whereas ECV and LA strain rate remained independently associated with frailty.

CONCLUSIONS

These findings suggest a significant overlap in pathways associated with subclinical cardiac dysfunction, cardiovascular fibrosis, and physical frailty.

Racial and ethnic differences in the risk of dementia diagnosis under hypothetical blood pressure-lowering interventions: The Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

Substantial racial and ethnic disparities in hypertension and dementia exist in the United States. We evaluated the effect of maintaining systolic blood pressure (SBP) below clinical thresholds on dementia incidence.

METHODS

We included 6806 Multi-Ethnic Study of Atherosclerosis participants (44 to 84 years old). We implemented the parametric g-formula to simulate the hypothetical interventions to reduce SBP below 120 and 140 mmHg over time, accounting for time-varying confounding. We estimated risk ratios (RRs) and risk differences for dementia incidence at 19 years.

RESULTS

The RRs (95% confidence intervals [CIs]) comparing an intervention reducing SBP below 120 mmHg to no intervention were 0.93 (0.87 to 0.99) for total sample, 0.95 (0.88 to 1.02) for White, 0.90 (0.79 to 1.02) for Black, 0.90 (0.78 to 1.05) for Latino, and 1.16 (0.83 to 1.55) for Chinese American participants. Results for lowering SBP below 140 mmHg and with death as competing event were attenuated.

DISCUSSION

The reduction of SBP below 120 mmHg over time has modest effects on reducing dementia incidence. More work is needed to understand the heterogeneity across racial and ethnic groups.

HIGHLIGHTS

There is a potential beneficial effect in lowering SBP to reduce the risk of dementia, which may vary by race and ethnicity. The percentage of participants who would need intervention on blood pressure to meet clinical thresholds is greater for Black and Latino communities. Results are sensitive to the way that death is specified in the research question and analysis.

Gut Microbiome Multi-Omics and Cognitive Function in the Hispanic Community Health Study/Study of Latinos- Investigation of Neurocognitive Aging

INTRODUCTION

We conducted a study within the Hispanic Community Health Study/Study of Latinos- Investigation of Neurocognitive Aging (HCHS/SOL-INCA) cohort to examine the association between gut microbiome and cognitive function.

METHODS

We analyzed the fecal metagenomes of 2,471 HCHS/SOL-INCA participants to, cross-sectionally, identify microbial taxonomic and functional features associated with global cognitive function. Omnibus (PERMANOVA) and feature-wise analyses (MaAsLin2) were conducted to identify microbiome-cognition associations, and specific microbial species and pathways (Kyoto Encyclopedia of Genes and Genomes (KEGG modules) associated with cognition.

RESULTS

Eubacterium species( E. siraeum and E. eligens ), were associated with better cognition. Several KEGG modules, most strongly Ornithine, Serine biosynthesis and Urea Cycle, were associated with worse cognition.

DISCUSSION

In a large Hispanic/Latino cohort, we identified several microbial taxa and KEGG pathways associated with cognition.

Lessons Learned from Immigrant Health Cohorts: A Review of the Evidence and Implications for Policy and Practice in Addressing Health Inequities among Asian Americans, Native Hawaiians, and Pacific Islanders

The health of Asian Americans, Native Hawaiians, and Pacific Islanders (AANHPI) is uniquely impacted by structural and social determinants of health (SSDH) shaped by immigration policies and colonization practices, patterns of settlement, and racism. These SSDH also create vast heterogeneity in disease risks across the AANHPI population, with some ethnic groups having high disease burden, often masked with aggregated data. Longitudinal cohort studies are an invaluable tool to identify risk factors of disease, and epidemiologic cohort studies among AANHPI populations have led to seminal discoveries of disease risk factors. This review summarizes the limited but growing literature, with a focus on SSDH factors, from seven longitudinal cohort studies with substantial AANHPI samples. We also discuss key information gaps and recommendations for the next generation of AANHPI cohorts, including oversampling AANHPI ethnic groups; measuring and innovating on measurements of SSDH; emphasizing the involvement of scholars from diverse disciplines; and, most critically, engaging community members to ensure relevancy for public health, policy, and clinical impact.

Association of multiple metabolic and cardiovascular markers with the risk of cognitive decline and mortality in adults with Alzheimer's disease and AD-related dementia or cognitive decline: a prospective cohort study

Background and objectives

There is a scarcity of data stemming from large-scale epidemiological longitudinal studies focusing on potentially preventable and controllable risk factors for Alzheimer's disease (AD) and AD-related dementia (ADRD). This study aimed to examine the effect of multiple metabolic factors and cardiovascular disorders on the risk of cognitive decline and AD/ADRD.

Methods

We analyzed a cohort of 6,440 participants aged 45-84 years at baseline. Multiple metabolic and cardiovascular disorder factors included the five components of the metabolic syndrome [waist circumference, high blood pressure (HBP), elevated glucose and triglyceride (TG) concentrations, and reduced high-density lipoprotein cholesterol (HDL-C) concentrations], C-reactive protein (CRP), fibrinogen, interleukin-6 (IL-6), factor VIII, D-dimer, and homocysteine concentrations, carotid intimal-medial thickness (CIMT), and urine albumin-to-creatinine ratio (ACR). Cognitive decline was defined using the Cognitive Abilities Screening Instrument (CASI) score, and AD/ADRD cases were classified using clinical diagnoses.

Results

Over an average follow-up period of 13 years, HBP and elevated glucose, CRP, homocysteine, IL-6, and ACR concentrations were significantly associated with the risk of mortality in the individuals with incident AD/ADRD or cognitive decline. Elevated D-dimer and homocysteine concentrations, as well as elevated ACR were significantly associated with incident AD/ADRD. Elevated homocysteine and ACR were significantly associated with cognitive decline. A dose-response association was observed, indicating that an increased number of exposures to multiple risk factors corresponded to a higher risk of mortality in individuals with cognitive decline or with AD/ADRD.

Conclusion

Findings from our study reaffirm the significance of preventable and controllable factors, including HBP, hyperglycemia, elevated CRP, D-dimer, and homocysteine concentrations, as well as, ACR, as potential risk factors for cognitive decline and AD/ADRD.

Spatial scale effects on associations between built environment and cognitive function: Multi-Ethnic Study of Atherosclerosis

Built environments have the potential to favorably support cognitive function. Despite growing work on this topic, most of the work has ignored variation in the spatial scale of the effect. The issue with spatial scale effects is that the size and shape of the areal unit within which built environment characteristics are measured naturally influence the built environment exposure metric and thus the estimated associations with health. We used spatial distributed lag modeling (DLM) to estimate how associations between built environment exposures (walkable destinations [WD], social destinations [SD]) and change in cognition varied across distance of these destinations from participants' residences. Cognition was assessed as maintained/improved processing speed (PS) and global cognition (GC). Person-level data from Exam 5 (2010-2012) and Exam 6 (2016-2018) of the Multi-Ethnic Study of Atherosclerosis was used (N = 1380, mean age 67). Built environment data were derived from the National Establishment Time Series. Higher availability of walkable and social destinations at closer distance from participants' residence was associated with maintained/improved PS. The adjusted associations between maintained/improved PS and destinations waned with increasing distance from the residence; associations were evident until approximately 1.9-km for WD and 1.5-km for SD. Associations were most apparent for participants living in areas with high population density. We found little evidence for associations between change in GC and built environment at any distance. These results highlight the importance of identifying appropriate spatial scale to understand the mechanisms for built environment-cognition associations.

Retinal vessel caliber and cognitive performance: the multi-ethnic study of atherosclerosis (MESA)

Retinal vessel calibers share anatomic and physiologic characteristics with the cerebral vasculature and can be visualized noninvasively. In light of the known microvascular contributions to brain health and cognitive function, we aimed to determine if, in a community based-study, retinal vessel calibers and change in caliber over 8 years are associated with cognitive function or trajectory. Participants in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort who completed cognitive testing at Exam 5 (2010-2012) and had retinal vascular caliber measurements (Central Retinal Artery and Vein Equivalents; CRAE and CRVE) at Exam 2 (2002-2004) and Exam 5 were included. Using multivariable linear regression, we evaluated the association of CRAE and CRVE from Exam 2 and Exam 5 and their change between the two exams with scores on tests of global cognitive function (Cognitive Abilities Screening Instrument; CASI), processing speed (Digit Symbol Coding; DSC) and working memory (Digit Span; DS) at Exam 5 and with subsequent change in cognitive scores between Exam 5 and Exam 6 (2016-2018).The main effects are reported as the difference in cognitive test score per SD increment in retinal vascular caliber with 95% confidence intervals (CI). A total of 4334 participants (aged 61.6 ± 9.2 years; 53% female; 41% White) completed cognitive testing and at least one retinal assessment. On multivariable analysis, a 1 SD larger CRAE at exam 5 was associated with a lower concomitant CASI score (- 0.24, 95% CI - 0.46, - 0.02). A 1 SD larger CRVE at exam 2 was associated with a lower subsequent CASI score (- 0.23, 95%CI - 0.45, - 0.01). A 1 SD larger CRVE at exam 2 or 5 was associated with a lower DSC score [(- 0.56, 95% CI - 1.02, - 0.09) and - 0.55 (95% CI - 1.03, - 0.07) respectively]. The magnitude of the associations was relatively small (2.8-3.1% of SD). No significant associations were found between retinal vessel calibers at Exam 2 and 5 with the subsequent score trajectory of cognitive tests performance over an average of 6 years. Wider retinal venular caliber was associated with concomitant and future measures of slower processing speed but not with later cognitive trajectory. Future studies should evaluate the utility of these measures in risk stratification models from a clinical perspective as well as for screening on a population level.

Association of fractal dimension and other retinal vascular network parameters with cognitive performance and neuroimaging biomarkers: The Multi-Ethnic Study of Atherosclerosis (MESA)

INTRODUCTION

Retinal vascular network changes may reflect the integrity of the cerebral microcirculation, and may be associated with cognitive impairment.

METHODS

Associations of retinal vascular measures with cognitive function and MRI biomarkers were examined amongst Multi-Ethnic Study of Atherosclerosis (MESA) participants in North Carolina who had gradable retinal photographs at Exams 2 (2002 to 2004, n = 313) and 5 (2010 to 2012, n = 306), and detailed cognitive testing and MRI at Exam 6 (2016 to 2018).

RESULTS

After adjustment for covariates and multiple comparisons, greater arteriolar fractal dimension (FD) at Exam 2 was associated with less isotropic free water of gray matter regions (β = -0.0005, SE = 0.0024, p = 0.01) at Exam 6, while greater arteriolar FD at Exam 5 was associated with greater gray matter cortical volume (in mm3 , β = 5458, SE = 20.17, p = 0.04) at Exam 6.

CONCLUSION

Greater arteriolar FD, reflecting greater complexity of the branching pattern of the retinal arteries, is associated with MRI biomarkers indicative of less neuroinflammation and neurodegeneration.

The magnitude and direction of the relationship between risk factor and cognition depends on age: a pooled analysis of 5 community-based studies

The mixed evidence of the association between high levels of cardiovascular risk factors (CVRF) and the risk for cognitive impairment may be due to confounding of age across studies. We pooled and harmonized individual-level data (30,967 persons, age range 42-96 years) from five prospective cohorts to investigate by 1 year age increments to investigate whether or not there is change in slope describing the association of CVRF to a cognitive outcome (Digit Symbol Substitution Test; DSST). The CVRF included: systolic and diastolic blood pressure, total cholesterol, fasting glucose and body mass index. Linear and quadratic piecewise regression models were fit to the trajectory patterns of these slopes (betas). The pattern of yearly slope changes showed higher CVRF were associated with lower DSST, but associations attenuated toward zero as age increased for all but DBP where 1 year slopes for DBP changed direction from negative to positive from mid- to late-age. Age is not only a driver of cognitive decline-age also modifies the direction and strength of the association of cognitive function to CVRF and cohort age may be one reason why the evidence for CVRF-CD association is mixed.

The association of upper airway anatomy with cognitive test performance: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Numerous upper airway anatomy characteristics are risk factors for sleep apnea, which affects 26% of older Americans, and more severe sleep apnea is associated with cognitive impairment. This study explores the pathophysiology and links between upper airway anatomy, sleep, and cognition.

METHODS

Participants in the Multi-Ethnic Study of Atherosclerosis underwent an upper airway MRI, polysomnography to assess sleep measures including the apnea-hypopnea index (AHI) and completed the Cognitive Abilities Screening Instrument (CASI). Two model selection techniques selected from among 67 upper airway measures those that are most strongly associated with CASI score. The associations of selected upper airway measures with AHI, AHI with CASI score, and selected upper airway anatomy measures with CASI score, both alone and after adjustment for AHI, were assessed using linear regression.

RESULTS

Soft palate volume, maxillary divergence, and upper facial height were significantly positively associated with higher CASI score, indicating better cognition. The coefficients were small, with a 1 standard deviation (SD) increase in these variables being associated with a 0.83, 0.75, and 0.70 point higher CASI score, respectively. Additional adjustment for AHI very slightly attenuated these associations. Larger soft palate volume was significantly associated with higher AHI (15% higher AHI (95% CI 2%,28%) per SD). Higher AHI was marginally associated with higher CASI score (0.43 (95% CI 0.01,0.85) per AHI doubling).

CONCLUSIONS

Three upper airway measures were weakly but significantly associated with higher global cognitive test performance. Sleep apnea did not appear to be the mechanism through which these upper airway and cognition associations were acting. Further research on the selected upper airway measures is recommended.

Association of brain microbleeds with risk factors, cognition, and MRI markers in MESA

INTRODUCTION

Little is known about the epidemiology of brain microbleeds in racially/ethnically diverse populations.

METHODS

In the Multi-Ethnic Study of Atherosclerosis, brain microbleeds were identified from 3T magnetic resonance imaging susceptibility-weighted imaging sequences using deep learning models followed by radiologist review.

RESULTS

Among 1016 participants without prior stroke (25% Black, 15% Chinese, 19% Hispanic, 41% White, mean age 72), microbleed prevalence was 20% at age 60 to 64.9 and 45% at ≥85 years. Deep microbleeds were associated with older age, hypertension, higher body mass index, and atrial fibrillation, and lobar microbleeds with male sex and atrial fibrillation. Overall, microbleeds were associated with greater white matter hyperintensity volume and lower total white matter fractional anisotropy.

DISCUSSION

Results suggest differing associations for lobar versus deep locations. Sensitive microbleed quantification will facilitate future longitudinal studies of their potential role as an early indicator of vascular pathology.

Self-reported experiences of discrimination and incident dementia

INTRODUCTION

Discrimination negatively impacts health and may contribute to racial/ethnic disparities in dementia risk.

METHODS

Experiences of lifetime and everyday discrimination were assessed among 6509 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We assessed the association of discrimination with incidence of dementia including adjustment for important risk factors, cohort attrition, and we assessed for effect modification by race/ethnicity.

RESULTS

Prevalence of any lifetime discrimination in MESA was 42%, highest among Black adults (72%). Over a median 15.7 years of follow-up, there were 466 incident cases of dementia. Lifetime discrimination, but not everyday discrimination, was associated with incident dementia (Wald p = 0.03). Individuals reporting lifetime discrimination in ≥2 domains (compared to none) had greater risk for dementia (hazard ratio: 1.40; 95%: 1.08, 1.82) after adjustment for sociodemographic, clinical, and behavioral risk factors. Associations did not differ by race/ethnicity.

CONCLUSIONS

These findings demonstrate an association of greater experiences of lifetime discrimination with incident dementia.

Acute beetroot juice reduces blood pressure in young Black and White males but not females

A complex interplay of social, lifestyle, and physiological factors contribute to Black Americans having the highest blood pressure (BP) in America. One potential contributor to Black adult's higher BP may be reduced nitric oxide (NO) bioavailability. Therefore, we sought to determine whether augmenting NO bioavailability with acute beetroot juice (BRJ) supplementation would reduce resting BP and cardiovascular reactivity in Black and White adults, but to a greater extent in Black adults. A total of 18 Black and 20 White (∼equal split by biological sex) young adults completed this randomized, placebo-controlled (nitrate (NO3-)-depleted BRJ), crossover design study. We measured heart rate, brachial and central BP, and arterial stiffness (via pulse wave velocity) at rest, during handgrip exercise, and during post-exercise circulatory occlusion. Compared with White adults, Black adults exhibited higher pre-supplementation resting brachial and central BP (Ps ≤0.035; e.g., brachial systolic BP: 116(11) vs. 121(7) mmHg, P = 0.023). Compared with placebo, BRJ (∼12.8 mmol NO3-) reduced resting brachial systolic BP similarly in Black (Δ-4±10 mmHg) and White (Δ-4±7 mmHg) adults (P = 0.029). However, BRJ supplementation reduced BP in males (Ps ≤ 0.020) but not females (Ps ≥ 0.299). Irrespective of race or sex, increases in plasma NO3- were associated with reduced brachial systolic BP (ρ = -0.237, P = 0.042). No other treatment effects were observed for BP or arterial stiffness at rest or during physical stress (i.e., reactivity); Ps ≥ 0.075. Despite young Black adults having higher resting BP, acute BRJ supplementation reduced systolic BP in young Black and White adults by a similar magnitude, an effect that was driven by males.

The rocky road of 55 years of change in the relationship of cardiovascular risk factors to cognition

The mixed evidence that high levels of cardiovascular risk factors (CVRF) are associated with lower cognitive test scores of may be due to confounding of age across studies. We pooled and harmonized individual-level data (30,967 persons, age range 42-96y) from five prospective cohorts to examine the trajectories of betas estimating 1-year-age associations of a cognitive outcome (Digit Symbol Substitution Test; DSST) to five CVRF: systolic and e blood pressure, total cholesterol, fasting glucose and body mass index. Linear and quadratic piecewise regression models were fit to the trajectory patterns of these betas. The trajectories showed with each 1-year age increment, higher CVRF were associated with lower DSST, but associations attenuated toward zero as age increased. In addition, the pattern across age of each CVRF-DSST trajectory ranged from linear to non-liner. Without accounting for participant age in cohort comparisons, conclusions about the potential benefit on cognitive function of modifiable CVRF control will continue to be mixed and lead to delays in developing prevention programs.

Long-term exposure to ambient air pollution and cognitive function in older US adults: The Multi-Ethnic Study of Atherosclerosis

Air pollution effects on cognitive function have been increasingly recognized. Little is known about the impact of different sources of fine particulate (PM2.5). We aim to evaluate the associations between long-term air pollution exposure, including source-specific components in PM2.5, and cognition in older adults.

Methods

Cognitive assessment, including the Cognitive Abilities Screening Instrument (CASI), Digit Symbol Coding (DSC), and Digit Span (DS), was completed in 4392 older participants in the United States during 2010-2012. Residence-specific air pollution exposures (i.e., oxides of nitrogen [NO2/NOx], PM2.5 and its components: elemental carbon [EC], organic carbon [OC], sulfur [S], and silicon [Si]) were estimated by geo-statistical models. Linear and logistic regression models were used to estimate the associations between each air pollutants metric and cognitive function.

Results

An interquartile range (IQR) increase in EC (0.8 μg/m3) and Si (23.1 ng/m3) was associated with -1.27 (95% confidence interval [CI]: -0.09, -2.45) and -0.88 (95% CI: -0.21, -1.54) lower CASI scores in global cognitive function. For each IQR increase in Si, the odds of low cognitive function (LCF) across domains was 1.29 times higher (95% CI: 1.04, 1.60). For other tests, NO X was associated with slower processing speed (DSC: -2.01, 95% CI: -3.50, -0.52) and worse working memory (total DS: -0.4, 95% CI: -0.78, -0.01). No associations were found for PM2.5 and two PM2.5 components (OC and S) with any cognitive function outcomes.

Conclusion

Higher exposure to traffic-related air pollutants including both tailpipe (EC and NO x ) and non-tailpipe (Si) species were associated with lower cognitive function in older adults.

Association of Vascular Risk Scores and Cognitive Performance in a Diverse Cohort: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Vascular risk scores are associated with incident dementia. Information regarding their association with cognitive performance and decline in racially/ethnically diverse cohorts is lacking.

METHOD

In 4 392 Multi-Ethnic Study of Atherosclerosis participants (aged 60.1 ± 9.4 years; 53% women; 41% White, 11% Chinese American, 26% African American, 21% Hispanic), we compared associations of Exam 1 (2000-2002) Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE), Framingham Stroke Risk Profile (FSRP), and atherosclerotic cardiovascular disease pooled cohort equation (ASCVD-PCE) risk scores with Exam 5 (2010-2012) Cognitive Abilities Screening Instrument (CASI), Digit Symbol Coding (DSC), and Digit Span (DS) cognitive test performance using multivariable linear regression, and examined racial/ethnic interactions. In 1 838 participants with repeat CASI data at Exam 6 (2016-2018), we related risk scores to odds of a 1-SD decline in CASI performance using multivariable logistic regression.

RESULTS

SD increments in each risk score were associated with worse cognitive performance. CAIDE had stronger associations with CASI performance than the FSRP and ASCVD-PCE, but associations of ASCVD-PCE with the DSC and DS were similar to CAIDE (difference in β [95% CI] = -0.57 [-1.48, 0.34] and -0.21 [-0.43, 0.01], respectively). Race/ethnicity modified associations. For example, associations between CAIDE and CASI were greater in African Americans and Hispanics than in Whites (difference in β = 0.69 [0.02, 1.36] and 1.67 [0.95, 2.39], respectively). Risk scores were comparably associated with decline in CASI performance.

CONCLUSIONS

Antecedent vascular risk scores are associated with cognitive performance and decline in the 4 most common U.S. racial/ethnic groups, but associations differ among risk scores and by race/ethnicity.

Relation of Progression of Coronary Artery Calcium to Dementia (from the Multi-Ethnic Study of Atherosclerosis)

Baseline coronary artery calcification has been shown to be associated with dementia. However, the value of coronary artery calcium (CAC) progression in the prediction of dementia remains unclear. In this study, we examined the association between CAC progression and dementia in the Multi-Ethnic Study of Atherosclerosis. The Multi-Ethnic Study of Atherosclerosis is a prospective study consisting of 6,814 participants 45 to 84 years of age, free of overt cardiovascular disease at baseline. A total of 5,570 subjects had baseline and follow-up CAC scans approximately 2.5 years apart and were included this analysis. A total of 4,173 of these participants completed cognitive testing with the Cognitive Abilities Screening Instrument (CASI) approximately 10 years after the baseline CAC scan. Dementia diagnoses were identified using International Classification of Diseases codes from hospitalizations, death certificates, and medications used to treat dementia. The absolute change between baseline and follow-up CAC was used to assess CAC progression. Cox proportional hazards and multivariable linear regression models were used to examine the association of CAC progression with incident dementia and with CASI score. Over a median follow-up of 13.2 (interquartile range: 11.2 to 15.3) years, 350 participants developed incident dementia. CAC progression showed no association with dementia risk after adjustment for age, gender, race/ethnicity, vascular risk factors, and baseline CAC score. There was no association of CAC progression with CASI score in any adjusted model. In conclusion, progression of CAC over approximately 2.5 years was not associated with increased risk of dementia after adjustment for demographic variables, vascular risk factors, and baseline CAC.

High visit‐to‐visit blood pressure variability predicts global cognitive decline: The Multi‐Ethnic Study of Atherosclerosis

Background

Methods

Results

Conclusion

Prediction of Cognitive Decline Using Heart Rate Fragmentation Analysis: The Multi-Ethnic Study of Atherosclerosis

Background: Heart rate fragmentation (HRF), a new non-invasive metric quantifying cardiac neuroautonomic function, is associated with increasing age and cardiovascular disease. Since these are risk factors for cognitive decline and dementia, in the Multi-Ethnic Study of Atherosclerosis (MESA), we investigated whether disrupted cardiac neuroautonomic function, evidenced by increased HRF, would be associated with worse cognitive function assessed concurrently and at a later examination, and with greater cognitive decline.

Methods: HRF was derived from the ECG channel of the polysomnographic recordings obtained in an ancillary study (n = 1,897) conducted in conjunction with MESA exam 5 (2010–2012). Cognitive function was assessed at exam 5 and 6.4 ± 0.5 years later at exam 6 (2016–2018) with tests of global cognitive performance (the Cognitive Abilities Screening Instrument, CASI), processing speed (Digit Symbol Coding, DSC) and working memory (Digit Span). Multivariable regression models were used to quantify the associations between HRF indices and cognitive scores.

Results: The participants’ mean age was 68 ± 9 years (54% female). Higher HRF at baseline was independently associated with lower cognitive scores at both exams 5 and 6. Specifically, in cross-sectional analyses, a one-standard deviation (SD) (13.7%) increase in HRF was associated with a 0.51 (95% CI: 0.17–0.86) points reduction in CASI and a 1.12 (0.34–1.90) points reduction in DSC. Quantitatively similar effects were obtained in longitudinal analyses. A one-SD increase in HRF was associated with a 0.44 (0.03–0.86) and a 1.04 (0.28–1.81) points reduction in CASI and DSC from exams 5 to 6, respectively. HRF added predictive value to the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE-APOE-ε4) risk score and to models adjusted for serum concentration of NT-proBNP, an analyte associated with cognitive impairment and dementia.

Conclusion: Increased HRF assessed during sleep was independently associated with diminished cognitive performance (concurrent and future) and with greater cognitive decline. These findings lend support to the links between cardiac neuroautonomic regulation and cognitive function. As a non-invasive, repeatable and inexpensive probe, HRF technology may be useful in monitoring cognitive status, predicting risk of dementia and assessing therapeutic interventions.

Associations among vascular risk factors, neuroimaging biomarkers, and cognition: Preliminary analyses from the Multi-Ethnic Study of Atherosclerosis (MESA)

INTRODUCTION

Little is known about how antecedent vascular risk factor (VRF) profiles impact late-life brain health.

METHODS

We examined baseline VRFs, and cognitive testing and neuroimaging measures (β-amyloid [Aβ] PET, MRI) in a diverse longitudinal cohort (N = 159; 50% African-American, 50% White) from Wake Forest's Multi-Ethnic Study of Atherosclerosis Core.

RESULTS

African-Americans exhibited greater baseline Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE), Framingham stroke risk profile (FSRP), and atherosclerotic cardiovascular disease risk estimate (ASCVD) scores than Whites. We observed no significant racial differences in Aβ positivity, cortical thickness, or white matter hyperintensity (WMH) volume. Higher baseline VRF scores were associated with lower cortical thickness and greater WMH volume, and FSRP and CAIDE were associated with Aβ. Aβ was cross-sectionally associated with cognition, and all imaging biomarkers were associated with greater 6-year cognitive decline.

DISCUSSION

Results suggest the convergence of multiple vascular and Alzheimer's processes underlying neurodegeneration and cognitive decline.

The impact of long- and short-term exposure to different ambient air pollutants on cognitive function in China

In the field of environmental health, the impact of air pollution on people's cognitive function is receiving increasing attention. Various air pollution exposures and different exposure periods result in different degrees of damage to cognition. This paper first used CFPS cognitive tests to evaluate the cognitive function of 15,163 adults in 25 provinces of China. Next, based on the geographical location of the population, the kriging interpolation method was applied to evaluate the different exposure periods for various air pollutants (PM_2.5, NO₂ and O₃). Air pollution exposures lasting 3 years and more were referred to in this paper as long-term exposures, while those lasting<3 years were short-term exposures. This paper used an ordinary least squares (OLS) regression model to explore the differential effects of various air pollutant exposures and discussed the impact of long- and short-term exposure to pollutants. Subsequently, Moran's index was used to test the spatial connection for cognitive function, and the spatial error model was used for analysis in the spatial autoregressive model. This research also conducted a heterogeneity study on the justice of air pollutant exposure among people with different characteristics. The population was classified according to cognitive function and geographic location using OLS regression and quantile regression, and a propensity score matching (PSM) model was used for cross-validation to explore whether people with different characteristics and attributes were differentially exposed to air pollution. We found that there were significant negative relationships between air pollutant exposure and cognitive function, especially PM_2.5 exposure and long-term exposure. In addition, air pollution had significantly different impacts on cognition based on the different characteristics and attributes of the person exposed. This study helps by analyzing the socioeconomic factors that affect the level of exposure and suggests that groups who are vulnerable to environmental pollution should be protected and the occurrence of injustice reduced. The study also provides a reference for the distribution of pollution sources and the allocation of health resources, which can be useful for population distribution planning.

Associations Between Neighborhood Park Access and Longitudinal Change in Cognition in Older Adults: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Preliminary evidence suggests associations between neighborhood park access and better late-life cognition and reduced Alzheimer's disease (AD) risk.

OBJECTIVE

Examine associations between neighborhood park access and longitudinal change in cognition among U.S. older adults without dementia.

METHODS

We used 2000-2018 observational data from the population-based, multi-site Multi-Ethnic Study of Atherosclerosis (n = 1,733). Measures included proportion of neighborhood park space (park access), distance to nearest park, and 6-year dichotomous and continuous change in scores on the Cognitive Abilities Screening Instrument (CASI; global cognition) and Digit Symbol Coding task (processing speed). Multivariable random intercept models tested main associations and mediation by depressive symptoms, physical activity, and PM2.5 exposure. Effect modification by race (African Americans/Blacks versus Whites) was tested using interaction terms.

RESULTS

Greater park access (equivalent to 10%more in 1/2-mile around home) was associated with maintained/improved CASI score over six years independent of several covariates including individual- and neighborhood-level socioeconomic status (Odds ratio: 1.04; 95%confidence interval: 1.00-1.08). No other associations were observed with the dichotomous or continuous measures of cognitive change and no mediators were found. While a borderline association was seen between greater park access and maintained/improved CASI for African Americans/Blacks but not for Whites, effect modification was not confirmed by testing interaction terms.

CONCLUSION

Neighborhood park access may help maintain/improve late-life global cognition. However, our findings need replication in other population-based studies and regions. Additionally, studies are needed to determine if associations between park access and change in cognition vary by race/ethnicity to inform intervention efforts.

Macro and micro sleep architecture and cognitive performance in older adults

We sought to determine which facets of sleep neurophysiology were most strongly linked to cognitive performance in 3,819 older adults from two independent cohorts, using whole-night electroencephalography. From over 150 objective sleep metrics, we identified 23 that predicted cognitive performance, and processing speed in particular, with effects that were broadly independent of gross changes in sleep quality and quantity. These metrics included rapid eye movement duration, features of the electroencephalography power spectra derived from multivariate analysis, and spindle and slow oscillation morphology and coupling. These metrics were further embedded within broader associative networks linking sleep with aging and cardiometabolic disease: individuals who, compared with similarly aged peers, had better cognitive performance tended to have profiles of sleep metrics more often seen in younger, healthier individuals. Taken together, our results point to multiple facets of sleep neurophysiology that track coherently with underlying, age-dependent determinants of cognitive and physical health trajectories in older adults.

Markers of adiposity, insulin resistance, prediabetes and cognitive function at baseline of the Brazilian Longitudinal Study of Adult Health (ELSA - Brasil)

AIM

The aim of the study is to investigate whether adiposity markers, insulin resistance and prediabetes are associated with cognitive performance in middle-aged men and women without diabetes.

METHODS

Cross-sectional study with 11,115 adults without diabetes (34-64 years old). Cognitive performance was tested by word-list learning, word-list delayed recall, word recognition tests, semantic and phonemic verbal fluency tests and trail making test B. Linear regression models and generalized linear regression with logarithmic links between the cognitive tests and anthropometric indicators (body mass index [BMI]), insulin resistance (Homeostasis Model Assessment for Insulin Resistance [HOMA-IR]), and prediabetes (impaired glucose tolerance) were stratified by sex. The results were adjusted for age, education, comorbidities, health-related behaviors, waist circumference, and lipids.

RESULTS

Among women, higher BMI was associated with poorer performance on phonemic verbal fluency test (β-0.02 [-0.04; -0.01]) and memory tests (β-0.05 [-0.07; -0.02]). Higher HOMA-IR was associated with poorer cognitive performance in memory (β-0.11 [-0.19; -0.01]) and phonemic verbal fluency tests (β-0.12 [-0.20; -0.04]). In men, HOMA-IR (β-0.15 [-0.25; -0.04]) and prediabetes (β-0.35 [-0.69; -0.03]) were associated with poorer performance on memory tests.

CONCLUSIONS

We found a significant association of BMI and HOMA-IR with cognitive performance in young and middle-aged adult women without diabetes. In men, we found an association between HOMA-IR and prediabetes and poorer performance on memory tests.

Associations between neighborhood park space and cognition in older adults vary by US location: The Multi-Ethnic Study of Atherosclerosis

We used cross-sectional Multi-Ethnic Study of Atherosclerosis data from six US cities/counties and adjusted multilevel linear regression to examine park space-cognition associations among non-demented older adults (n = 4084). We found that greater neighborhood park space 1-mile around the residence (measured continuously) was associated with better processing speed in the overall sample (estimate: 0.48; 95% CI: 0.03, 0.92). However, greater neighborhood park space (½-mile around residence) was associated with worse global cognition in Los Angeles, California (estimate: -2.66; 95% CI: -4.70, -0.62) and worse processing speed in Forsyth County, North Carolina (estimate: -0.72; 95% CI: -1.37, -0.08). Dichotomizing at the mean, having ≥6% park space (½-mile around residence) was associated with better global cognition in Saint Paul, Minnesota (estimate: 0.21; 95% CI: 0.05, 0.38), and better processing speed in New York City (estimate: 0.19; 95% CI: 0.04, 0.35). Park space-cognition associations varied by city/county, suggesting problems with pooling multiple sites without accounting for geographic context or regionally-varying park characteristics (e.g., quality).

Work Hours and Cognitive Function: The Multi-Ethnic Study of Atherosclerosis

Background

Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function.

Methods

Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44–84 years) reported hours per week worked in all jobs in Exams 1 (2000–2002), 2 (2002–2004), 3 (2004–2005), and 5 (2010–2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work.

Results

Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = –0.55, 95% CI = –0.99, –0.09) and (β = –0.80, –1.51, –0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = –0.80, –1.52, –0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function.

Conclusion

Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.

Association of Heart Rate Variability With Cognitive Performance: The Multi-Ethnic Study of Atherosclerosis

Background Heart rate variability (HRV) is associated with vascular risk factors for dementia, but whether HRV is associated with specific domains of cognitive performance is unclear. Methods and Results In the Multi-Ethnic Study of Atherosclerosis (N=3018; mean age 59.3±9.2 years), we assessed the relationship of 10-second HRV to scores on tests of global cognitive performance (Cognitive Abilities Screening Instrument), processing speed (Digit Symbol Coding), and working memory (Digit Span). HRV was computed as the SD of normal-normal intervals (SDNN) and root mean square of successive differences (RMSSD) at Exam 1 (2000-2002) and Exam 5 (2010-2012). Cognitive tests were administered at Exam 5. We report regression coefficients (β [95% CI]) representing cognitive test score change per 2-fold increase in HRV. After adjustment for age, race/ethnicity, sex, education, apolipoprotein E genotype, and cardiovascular risk factors and incident disease, higher Exam 1 (β=0.37 [0.06, 0.67]) and Exam 5 (β=0.31 [0.04, 0.59]) SDNN were associated with better Cognitive Abilities Screening Instrument performance. Higher Exam 1 (β=0.80 [0.17, 1.43]) and Exam 5 (β=0.63 [0.06, 1.20]) SDNN, and Exam 5 RMSSD (β=0.54 [0.01, 1.08]) were associated with better Digit Symbol Coding performance. Finally, higher Exam 5 SDNN was associated with better Digit Span performance (β=0.17 [0.01, 0.33]). Associations were attenuated after adjustment for resting heart rate. Conclusions Higher HRV is generally associated with better cognitive performance in this multi-ethnic cohort of aging adults, and further study of the relationship of autonomic function to cognition is warranted.

Associations between neighborhood built environment and cognition vary by apolipoprotein E genotype: Multi-Ethnic Study of Atherosclerosis

We examined whether neighborhood built environment (BE) and cognition associations in older adults vary by apolipoprotein E (APOE) genotype, a genetic risk factor for Alzheimer's disease (AD). We conducted a cross-sectional analysis of 4091 participants. Neighborhood characteristics included social and walking destination density (SDD, WDD), intersection density, and proportion of land dedicated to retail. Individuals were categorized as APOE ε2 (lower AD risk), APOE ε4 (higher AD risk), or APOE ε3 carriers. Among APOE ε2 carriers, greater proportion of land dedicated to retail was associated with better global cognition, and greater SDD, WDD, intersection density, and proportion of land dedicated to retail was associated with better processing speed. These associations were not observed in APOE ε3 or ε4 carriers. APOE ε2 carriers may be more susceptible to the potentially beneficial effects of denser neighborhood BEs on cognition; however, longitudinal studies are needed.

The associations among sociocultural factors and neuropsychological functioning in older American Indians: The Strong Heart Study

OBJECTIVE

Valid neuropsychological assessment is critical to the accurate diagnosis and effective treatment of diverse populations. American Indians and Alaska Natives experience substantial health disparities relative to the general U.S.

POPULATION

Given the dearth of studies on neuropsychological health in this population, we aimed to characterize neuropsychological performance among older American Indians with respect to age, sex, education, income, and language use.

METHOD

From 2010 to 2014, we recruited 818 American Indians aged 60 and older from the Cerebrovascular Disease and Its Consequences in American Indians Study, who comprised all of the surviving members of a cardiovascular study (Strong Heart Study). This cohort from 11 tribes resided on or near their home reservations in three geographic regions (Northern Plains, Southern Plains, and Southwest). Using a cross-sectional design investigating potential vascular brain injury, we administered a brief, targeted neuropsychological and motor function assessments.

RESULTS

Higher scores on neuropsychological tests were associated with younger age, female sex, more education, higher income, and less Native American language use. Similar associations were found for the motor tests, although men had higher scores on both motor function tests. After accounting for other sociocultural and health factors, age, sex, education, income, and Native American language use all had significant associations to the test scores.

CONCLUSIONS

Our findings may be used to guide research and inform clinical practice. The development of future normative studies for older American Indians will be more culturally appropriate when sociocultural factors are included. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Trends in Memory Problems and Race/Ethnicity in the National Health and Examination Survey, 1999-2014

Background

Little data exist to describe serial population-level trends in cognitive impairment- especially among minority communities. Because memory problems are among the first warning signs of cognitive impairment, they provide a potential method for monitoring changes in cognitive health at the population level. This exploratory study aimed to: 1) estimate prevalence of memory problems among US residents by race/ethnicity, age category; and 2) examine whether racial/ethnic differences in subjective cognitive concerns (memory problems) varied across recent time periods.

Design and Setting

Serial cross-sectional analysis of self-reported data from the National Health and Examination Survey (NHANES), 1999-2014.

Participants

20,585 participants aged ≥45 years during 1999-2014, who reported race/ethnicity as non-Hispanic White (NHW), non-Hispanic Black (NHB), and Latino/Hispanic.

Measurements

The outcome of interest was subjective cognitive concerns, identified as self-reported memory problems. The frequencies of memory problems were examined for each 4-year period, across racial/ethnic groups.

Results

In adjusted analyses, compared with older (aged ≥ 65 years) NHWs, disparities in subjective cognitive concerns were observed for older Latinos for most periods (range of AOR: 1.43 - 2.01, P<.05). Additionally, Latinos without a high school education had significantly higher odds of reporting memory problems than NHW in multiple periods (range of AOR: 1.95 - 2.17, P<.005), while Latino high school graduates did not. There were no significant changes in racial/ethnic differences in subjective cognitive concerns over time.

Conclusions

The prevalence of subjective cognitive concerns across time periods points to a need to engage patients - particularly older and less-educated Latinos - about warning signs for cognitive impairment. The impact of education on subjective cognitive concerns in older Latinos may be related to acculturation and warrant further investigation.

Greater Cognitive Deficits with Sleep-disordered Breathing among Individuals with Genetic Susceptibility to Alzheimer Disease. The Multi-Ethnic Study of Atherosclerosis

RATIONALE

There are conflicting findings regarding the link between sleep apnea and cognitive dysfunction.

OBJECTIVES

Investigate associations between indicators of sleep-disordered breathing (SDB) and cognitive function in the Multi-Ethnic Study of Atherosclerosis and assess effect modification by the apolipoprotein ε-4 (APOE-ε4) allele.

METHODS

A diverse population (N = 1,752) underwent type 2 in-home polysomnography, which included measurement of percentage sleep time less than 90% oxyhemoglobin saturation (%Sat < 90%) and apnea-hypopnea index (AHI). Epworth Sleepiness Scale score (ESS) and sleep apnea syndrome (SAS; AHI ≥ 5 and ESS > 10) were also analyzed. Cognitive outcomes included the Cognitive Abilities Screening Instrument; Digit Symbol Coding (DSC) test; and Digit Span Tests (DST) Forward and Backward.

RESULTS

Participants were 45.4% men, aged 68.1 years (SD, 9.1 yr) with a median AHI of 9.0 and mean ESS of 6.0. Approximately 9.7% had SAS, and 26.8% had at least one copy of the APOE-ε4 allele. In adjusted analyses, a 1-SD increase in %Sat < 90% and ESS score were associated with a poorer attention and memory assessed by the DST Forward score (β = -0.12 [SE, 0.06] and β = -0.13 [SE, 0.06], respectively; P ≤ 0.05). SAS and higher ESS scores were also associated with poorer attention and processing speed as measured by the DSC (β = -0.69 [SE, 0.35] and β = -1.42 [SE, 0.35], respectively; P < 0.05). The presence of APOE-ε4 allele modified the associations of %Sat < 90% with DST forward and of ESS with DSC (P_interaction ≤ 0.05).

CONCLUSIONS

Overnight hypoxemia and sleepiness were associated with cognition. The average effect estimates were small, similar to effect estimates for several other individual dementia risk factors. Associations were strongest in APOE-ε4 risk allele carriers. Our results (1) suggest that SDB be considered among a group of modifiable dementia risk factors, and (2) highlight the potential vulnerability of APOE-ε4 risk allele carriers with SDB.

Relationship of Lipids and Lipid-Lowering Medications With Cognitive Function: The Multi-Ethnic Study of Atherosclerosis

Studies on the relationship of cholesterol concentrations and lipid-lowering medications with dementia risk have yielded inconsistent findings. Therefore, we investigated the association of lipid concentrations and lipid-lowering medications with cognitive function in the Multi-Ethnic Study of Atherosclerosis across 3 different cognitive domains assessed by means of the Cognitive Abilities Screening Instrument (CASI; version 2), the Digit Symbol Coding (DSC) Test, and the Digit Span (DS) Test in 2010-2012. After adjustment for sociodemographic and confounding factors, including concentrations of other lipids and use of lipid-lowering medication, higher total cholesterol, low-density lipoprotein cholesterol, and non-high-density-lipoprotein cholesterol concentrations were modestly associated with higher DS Test scores. None of the lipid parameters were associated with CASI or DSC Test scores. Similarly, changes in lipid concentrations were not associated with any cognitive function test score. Using treatment effects model analysis and after adjusting for confounding factors, including lipid concentrations, the use of any lipid-lowering medication, especially statins, was associated with higher scores on the CASI and backward DS tests but not on the DSC and forward DS tests. Our study does not support a robust association between lipid concentrations and cognitive function or between the use of lipid-lowering medication, especially statins, and worse cognitive function.

Neighborhood built environment and cognition in non-demented older adults: The Multi-Ethnic Study of Atherosclerosis

Preliminary studies suggest that neighborhood social and built environment (BE) characteristics may affect cognition in older adults. Older adults are particularly vulnerable to the neighborhood environment due to a decreasing range of routine travel with increasing age. We examined if multiple neighborhood BE characteristics are cross-sectionally associated with cognition in a diverse sample of older adults, and if the BE-cognition associations vary by individual-level demographics. The sample included 4539 participants from the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression was used to examine the associations between five BE measures and four cognitive measures, and effect modification by individual-level education and race/ethnicity. In the overall sample, increasing social destination density, walking destination density, and intersection density were associated with worse overall cognition, whereas increasing proportion of land dedicated to retail was associated with better processing speed. Effect modification results suggest that the association between urban density and worse cognition may be limited to or strongest in those of non-white race/ethnicity. Although an increase in neighborhood retail destinations was associated with better cognition in the overall sample, these results suggest that certain BE characteristics in dense urban environments may have a disproportionately negative association with cognition in vulnerable populations. However, our findings must be replicated in longitudinal studies and other regional samples.

The Processing-Speed Impairment in Psychosis Is More Than Just Accelerated Aging

Processing speed is impaired in patients with psychosis, and deteriorates as a function of normal aging. These observations, in combination with other lines of research, suggest that psychosis may be a syndrome of accelerated aging. But do patients with psychosis perform poorly on tasks of processing speed for the same reasons as older adults? Fifty-one patients with psychotic illnesses and 90 controls with similar mean IQ (aged 19-69 years, all African American) completed a computerized processing-speed task, reminiscent of the classic digit-symbol coding task. The data were analyzed using the drift-diffusion model (DDM), and Bayesian inference was used to determine whether psychosis and aging had similar or divergent effects on the DDM parameters. Psychosis and aging were both associated with poor performance, but had divergent effects on the DDM parameters. Patients had lower information-processing efficiency ("drift rate") and longer nondecision time than controls, and psychosis per se did not influence response caution. By contrast, the primary effect of aging was to increase response caution, and had inconsistent effects on drift rate and nondecision time across patients and controls. The results reveal that psychosis and aging influenced performance in different ways, suggesting that the processing-speed impairment in psychosis is more than just accelerated aging. This study also demonstrates the potential utility of computational models and Bayesian inference for finely mapping the contributions of cognitive functions on simple neurocognitive tests.

Coronary Artery Calcium and Risk of Dementia in MESA (Multi-Ethnic Study of Atherosclerosis)

BACKGROUND

Studies suggest a link between vascular injuries and dementia. Only a few studies, however, examined a longitudinal relation of subclinical vascular disease with dementia. We tested whether baseline coronary artery calcium (CAC), a biomarker of subclinical vascular disease, is associated with incident dementia independent of vascular risk factors and APOE-ε4 genotype in a community-based sample.

METHODS AND RESULTS

We analyzed 6293 participants of MESA (Multi-Ethnic Study of Atherosclerosis), aged 45 to 84 years at baseline (2000-2002), initially free of cardiovascular disease and noticeable cognitive deficit. Dementia cases were identified using hospital and death certificate International Statistical Classification of Diseases and Related Health Problems codes. Cox models were used to obtain hazard ratios according to CAC category, or per 1 SD log2[CAC+1], adjusted for vascular risk factor, APOE-ε4, with or without exclusion of interim stroke or cardiovascular disease. We observed 271 dementia cases in a median follow-up of 12.2 years. Baseline CAC had a graded positive association with dementia risk. Compared with no CAC, CAC score of 1 to 400, 401 to 1000, and ≥1001 had increased risk of dementia by 23%, 35%, and 71%, respectively, (P_trend=0.026) after adjustment. 1 SD higher log2[CAC+1] was associated with 24% (95% confidence interval, 8%-41%; P=0.002) increase in dementia risk. Although the association was partially explained by interim stroke/cardiovascular disease, it remained significant even after excluding the interim events, or regardless of baseline age.

CONCLUSIONS

Higher baseline CAC was significantly associated with increased risk of dementia independent of vascular risk factor, APOE-ε4, and incident stroke. This is consistent with a hypothesis that vascular injuries play a role in the development of dementia.

Changes in metabolic risk factors over 10 years and their associations with late-life cognitive performance: The Multi-Ethnic Study of Atherosclerosis

Background

We examined whether changes in metabolic factors over 10 years were associated with cognitive performance.

Methods

Participants from the Multi-Ethnic Study of Atherosclerosis were followed since baseline (2000–2002) with five clinical examinations. At exam 5 (2010–2012), they received a short cognitive battery (Cognitive Abilities Screening Instrument [CASI], Digit Symbol Coding [DSC], and Digit Span [DS]). We examined associations between baseline metabolic factors and their changes over time before cognitive testing.

Results

Among 4392 participants, baseline metabolic disorders (fasting glucose, systolic and diastolic blood pressures) were significantly associated with poorer CASI, DSC, and DS scores measured 10 years later. Increases in blood pressure were associated with lower cognitive performance. Results did not differ by race/ethnicity and were stronger among those without the APOE ε4 allele.

Conclusions

Cognitive performance was associated with antecedent abnormalities in glucose metabolism and blood pressure increases. Findings appeared stronger among APOE ε4-negative participants.

Influence of schooling and age on cognitive performance in healthy older adults

Few studies have examined the influence of a low level of schooling on age-related cognitive decline in countries with wide social and economic inequalities by using the Cambridge Automated Neuropsychological Test Battery (CANTAB). The aim of the present study was to assess the influence of schooling on age-related cognitive decline using unbiased cognitive tests. CANTAB allows cognitive assessment across cultures and education levels with reduced interference of the examiner during data acquisition. Using two-way ANOVA, we assessed the influences of age and education on test scores of old adults (61–84 years of age). CANTAB tests included: Visual Sustained Attention, Reaction Time, Spatial Working Memory, Learning and Episodic Memory. All subjects had a minimum visual acuity of 20/30 (Snellen Test), no previous or current history of traumatic brain/head trauma, stroke, language impairment, chronic alcoholism, neurological diseases, memory problems or depressive symptoms, and normal scores on the Mini Mental State Examination (MMSE). Subjects were grouped according to education level (1 to 7 and ≥8 years of schooling) and age (60–69 and ≥70 years). Low schooling level was associated with significantly lower performance on visual sustained attention, learning and episodic memory, reaction time, and spatial working memory. Although reaction time was influenced by age, no significant results on post hoc analysis were detected. Our findings showed a significantly worse cognitive performance in volunteers with lower levels of schooling and suggested that formal education in early life must be included in the preventive public health agenda. In addition, we suggest that CANTAB may be useful to detect subtle cognitive changes in healthy aging.

Socioeconomic Status and Poor Health Outcome at 10 Years of Follow-Up in the Multi-Ethnic Study of Atherosclerosis

Background/Objectives

Predictors of healthy aging have not been well-studied using longitudinal data with demographic, clinical, subclinical, and genetic information. The objective was to identify predictors of poor health outcome at 10 years of follow-up in the Multi-Ethnic Study of Atherosclerosis (MESA).

Design

Prospective cohort study.

Setting

Population-based sample from 6 U.S. communities.

Participants

4,355 participants In the MESA Study.

Measurements

Poor health outcome at 10 years of follow-up was defined as having died or having clinical cardiovascular disease, depression, cognitive impairment, chronic obstructive pulmonary disease, or cancer other than non-melanoma skin cancer. Absolute risk regression was used to estimate risk differences in the outcome adjusting for demographic variables, clinical and behavioral risk factors, subclinical cardiovascular disease, and ApoE genotype. Models were weighted to account for selective attrition.

Results

Mean age at 10 years of follow-up was 69.5 years; 1,480 participants had a poor health outcome, 2,157 participants were in good health, and 718 were unknown. Older age, smoking, not taking a statin, hypertension, diabetes, and higher coronary calcium score were associated with higher probability of poor health outcome. After multivariable adjustment, participants in the lowest income and educational categories had 7 to 14% greater absolute risk of poor health outcome at 10 years of follow-up compared to those in the next highest categories of income or education (P = 0.002 for both). Those in the lowest categories of both income and education had 21% greater absolute risk of poor health outcome compared to those in the highest categories of both income and education.

Conclusions

Low income and educational level predict poor health outcome at 10 years of follow-up in an aging cohort, independent of clinical and behavioral risk factors and subclinical cardiovascular disease.

Education plays a greater role than age in cognitive test performance among participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Background

Brazil has gone through fast demographic, epidemiologic and nutritional transitions and, despite recent improvements in wealth distribution, continues to present a high level of social and economic inequality. The ELSA–Brasil, a cohort study, aimed at investigating cardiovascular diseases and diabetes, offers a great opportunity to assess cognitive decline in this aging population through time-sequential analyses drawn from the same battery of tests over time. The purpose of this study is to analyze the influence of sex, age and education on cognitive tests performance of the participants at baseline.

Methods

Analyses pertain to 14,594 participants with aged 35 to 74 years, who were functionally independent and had no history of stroke or use of neuroleptics, anticonvulsants, cholinesterase inhibitors or antiparkinsonian agents. Mean age was 52.0 ± 9.0 years and 54.2 % of participants were women. Cognitive tests included the word memory tests (retention, recall and recognition), verbal fluency tests (VFT, animals and letter F) and Trail Making Test B. Multivariable linear regression analysis was used to determine the influence of sociodemographic characteristics on the distribution of the final score of each test.

Results

Women had significant and slightly higher scores than men in all memory tests and VFT, but took more time to perform Trail B. Reduced performance in all tests was seen with an increase age and, more importantly, with decrease level of education. The word list and VFT scores decreased at about one word for every 10 years of age; whereas higher-educated participants scored four words more on the word list test, and six or seven more correct words on VFT, when compared to lower-educated participants. Additionally, the oldest and less educated participants showed significant lower response rates in all tests.

Conclusions

The higher influence of education than age in this Brazilian population reinforce the need for caution in analyzing and diagnosing cognitive impairments based on traditional cognitive tests and the importance of searching for education-free cognitive tests, especially in low and middle-income countries.