Examination of race and gender differences in predictors of neuropsychological decline and development of Alzheimer's disease

Cardiovascular Health, Race, and Decline in Cognitive Function in Midlife Women: The Study of Women's Health Across the Nation

BACKGROUND

Cognitive decline may progress for decades before dementia onset. Better cardiovascular health (CVH) has been related to less cognitive decline, but it is unclear whether this begins early, for all racial subgroups, and all domains of cognitive function. The purpose of this study was to determine the impact of CVH on decline in the 2 domains of cognition that decline first in White and Black women at midlife.

METHODS AND RESULTS

Subjects were 363 Black and 402 White women, similar in baseline age (mean±SD, 46.6±3.0 years) and education (15.7±2.0 years), from the Chicago site of the Study of Women's Health Across the Nation. Cognition, measured as processing speed and working memory, was assessed annually or biennially over a maximum of 20 years (mean±SD, 9.8±6.7 years). CVH was measured as Life's Essential 8 (blood pressure, body mass index, glucose, non-high-density lipoprotein cholesterol, smoking, physical activity, diet, sleep). Hierarchical linear mixed models identified predictors of cognitive decline with progressive levels of adjustment. There was a decline in processing speed that was explained by race, age, and the 3-way interaction of race, CVH, and time (F1,4308=8.8, P=0.003). CVH was unrelated to decline in White women but in Black women poorer CVH was associated with greater decline. Working memory did not decline in the total cohort, by race, or by CVH.

CONCLUSIONS

In midlife Black women, CVH promotion may be a target for preventing the beginnings of cognitive decline, thereby enhancing independent living with aging.

Concordance Between Logical Memory and Craft Story 21 in Community-Dwelling Older Adults: The Role of Demographic Factors And Cognitive Status

OBJECTIVE

Episodic memory loss, a hallmark symptom of Alzheimer's Disease, is frequently quantified by story memory performance. The National Alzheimer's Coordinating Center Uniform Data Set Neuropsychological Battery (UDSNB) replaced Logical Memory with Craft Story 21 in UDSNB Version 3. The concordance between these story memory tasks is poorly characterized in demographically diverse older adults, possibly jeopardizing the integrity of longitudinal data in aging cohorts.

METHOD

Einstein Aging Study participants (n = 298; Mage = 76.6; Meducation = 15; 66.4% women; 43.3% Non-Hispanic White) completed UDSNB measures, including Craft Story and Logical Memory. Classification as normal cognition (n = 206) or mild cognitive impairment (n = 90) was based on Jak/Bondi criteria. Analyses included correlations, linear regression, and equipercentile equating methods to characterize the relationship between Logical Memory and Craft Story. Multivariate linear mixed effects models explored the association of covariates and practice effects over follow-up, stratified by cognitive status and race/ethnicity.

RESULTS

Immediate (r = 0.54) and delayed (r = 0.56) versions of Logical Memory and Craft Story were moderately correlated. Age, education, depression, and female sex were associated with Logical Memory, while age, education, cognitive status, and male sex were associated with Craft Story. Significant differential effects of sex on story memory were observed.

CONCLUSIONS

We demonstrated that Logical Memory and Craft Story may be used largely interchangeably; however, memory may be enhanced for stories with a protagonist of the same sex as the participant. Craft Story was somewhat more associated with mild cognitive impairment in the overall sample, but especially in non-Hispanic Black participants. We discuss how results inform test selection considerations.

Pathways explaining racial/ethnic disparities in incident all-cause dementia among middle-aged US adults

INTRODUCTION

Racial disparities in dementia incidence exist, but less is known about their presence and drivers among middle-aged adults.

METHODS

We used time-to-event analysis among a sample of 4378 respondents (age 40-59 years at baseline) drawn from the third National Health and Nutrition Examination Surveys (NHANES III) with administrative linkage-spanning the years 1988-2014-to evaluate potential mediating pathways through socioeconomic status (SES), lifestyle, and health-related characteristics.

RESULTS

Compared with Non-Hispanic White (NHW) adults, Non-White adults had a higher incidence of AD-specific (hazard ratio [HR] = 2.05, 95% confidence interval [CI]: 1.21, 3.49) and all-cause dementia (HR = 2.01, 95% CI: 1.36, 2.98). Diet, smoking, and physical activity were among characteristics on the pathway between race/ethnicity, SES, and dementia, with health-mediating effects of smoking and physical activity on dementia risk.

DISCUSSION

We identified several pathways that may generate racial disparities in incident all-cause dementia among middle-aged adults. No direct effect of race was observed. More studies are needed to corroborate our findings in comparable populations.

Pathways explaining racial/ethnic and socio-economic disparities in dementia incidence: the UK Biobank study

BACKGROUND

Pathways explaining racial/ethnic disparities in dementia risk are under-evaluated.

METHODS

We examine those disparities and their related pathways among UK Biobank study respondents (50-74 y, N = 323,483; 3.6% non-White minorities) using a series of Cox proportional hazards and generalized structural equations models (GSEM).

RESULTS

After ≤15 years, 5,491 all-cause dementia cases were diagnosed. Racial minority status (RACE_ETHN, Non-White vs. White) increased dementia risk by 24% (HR = 1.24, 95% CI: 1.07-1.45, P = 0.005), an association attenuated by socio-economic status (SES), (HR = 1.12, 95% CI: 0.96-1.31). Total race-dementia effect was mediated through both SES and Life's Essential 8 lifestyle sub-score (LE8LIFESTYLE), combining diet, smoking, physical activity, and sleep factors. SES was inversely related to dementia risk (HR = 0.69, 95% CI: 0.67, 0.72, P < 0.001). Pathways explaining excess dementia risk among racial minorities included 'RACE_ETHN(-) → SES(-) → DEMENTIA', 'RACE_ETHN(-) → SES(-) → Poor cognitive performance, COGN(+) → DEMENTIA' and 'RACE_ETHN(-) → SES(+) → LE8LIFESTYLE(-) → DEMENTIA'.

CONCLUSIONS

Pending future interventions, lifestyle factors including diet, smoking, physical activity, and sleep are crucial for reducing racial and socio-economic disparities in dementia.

Pathophysiological Association of Alzheimer's Disease and Hypertension: A Clinical Concern for Elderly Population

Alzheimer's disease (AD), the most common cause of dementia and the fifth leading cause of death in the adult population has a complex pathophysiological link with hypertension (HTN). A growing volume of published literature on a parallel elevation of blood pressure (BP), amyloid plaques, and neurofibrillary tangles formation in post-middle of human brain cells has developed new, widely accepting foundations on this association. In particular, HTN in elderly life mediates cerebral blood flow dysfunction, neuronal dysfunction, and significant decline in cognitive impairment, primarily in the late-life populace, governing the onset of AD. Thus, HTN is an established risk factor for AD. Considering the impact of AD, 1.89 million deaths annually, and the failure of palliative therapies to cure AD, the scientific research community is looking to adopt integrated approaches to target early modified risk factors like HTN to reduce AD burden. The current review highlights the significance and impact of HTN-based prevention in lowering the AD burden in the elderly by providing a comprehensive overview of the physiological relationship between AD and HTN with an in-detail explanation of the role and applications of pathological biomarkers in this clinical association. The review will gain worth in presenting new insights and providing inclusive discussion on the correlation between HTN and cognitive impairment. It will increase across a wider scientific audience to expand understanding of this pathophysiological association.

Gender and ethnic/racial diversity in clinical neuropsychology: Updates from the AACN, NAN, SCN 2020 practice and "salary survey"

OBJECTIVE

Examination of gender and diversity issues within clinical neuropsychology, using data from the 2020 professional practice and "salary survey."

METHODS

Clinical neuropsychologists in the U.S. and Canada were invited to participate in an online survey. The final sample consisted of 1677 doctoral-level practitioners.

RESULTS

Approximately, 60% of responding neuropsychologists are women and 53.8% of those women identify as early career psychologists (ECPs). Conversely, a majority of men in the sample are advanced career psychologists (ACPs). Both genders work predominantly in institutions, but more men than women work in private practice. ACP men produce a greater number of peer-reviewed publications and conference presentations. Across all work settings, women earn significantly less than men, and are less satisfied with their incomes. Establishing and maintaining family life is the biggest obstacle to attaining greater income and job satisfaction for both genders. Ethnic/racial minority status was identified in 12.9% of respondents, with 59.2% being ECPs. Job satisfaction and hostility in the workplace vary across ethnic/racial minority groups. Hispanic/Latino(a) and White neuropsychologists report higher incomes, but there were no statistically significant differences between any of the groups.

CONCLUSIONS

Income and select practice differences persist between female and male neuropsychologists. There is a slow rate of increased ethnic/racial diversity over time, which is much more apparent among early career practitioners. Trajectories and demographics suggest that the gender income gap is unlikely to be improved by the next survey iteration in 2025, whereas it is very likely that ethnic/racial diversity will continue to increase gradually.

Race, polygenic risk and their association with incident dementia among older US adults

Dementia incidence increases steadily with age at rates that may vary across racial groups. This racial disparity may be attributable to polygenic risk, as well as lifestyle and behavioural factors. We examined whether Alzheimer's disease polygenic score and race predict Alzheimer's disease and other related dementia incidence differentially by sex and mediation through polygenic scores for other health and behavioural conditions. We used longitudinal data from the nationally representative Health and Retirement Study. We restricted participants to those with complete data on 31 polygenic scores, including Alzheimer's disease polygenic score (2006-2012). Among participants aged 55 years and older in 2008, we excluded those with any memory problems between 2006 and 2008 and included those with complete follow-up on incident Alzheimer's disease and all-cause dementia, between 2010 and 2018 (N = 9683), based on self- or proxy-diagnosis every 2 years (2010, 2012, 2014, 2016 and 2018). Cox proportional hazards and 4-way decomposition models were conducted. Analyses were also stratified by sex and by race. There were racial differences in all-cause dementia incidence (age and sex-adjusted model, per standard deviation: hazard ratio, HR = 1.34, 95% confidence interval, CI: 1.09-1.65, P = 0.007), partially driven by educational attainment and income. We also found independent associations of race (age and sex-adjusted model, African American versus White adults: HR = 2.07, 95% CI: 1.52-2.83, P < 0.001) and Alzheimer's disease polygenic score (age and sex-adjusted model, per SD: HR = 1.37, 95% CI: 1.00-1.87, P < 0.001) with Alzheimer's disease incidence, including sex differences whereby women had a stronger effect of Alzheimer's disease polygenic score on Alzheimer's disease incidence compared with men (P < 0.05 for sex by Alzheimer's disease polygenic score interaction) adjusting for race and other covariates. The total impact of Alzheimer's disease polygenic scores on Alzheimer's disease incidence was mostly direct, while the effect of race on all-cause dementia incidence was mediated through socio-economic, lifestyle and health-related factors. Finally, among the 30 polygenic scores we examined, the total effects on the pathway Alzheimer's disease polygenic score --> Other polygenic score --> Incident Alzheimer's or all-cause dementia, were statistically significant for all, driven primarily by the controlled direct effect (P< 0. 001). In conclusion, both race and Alzheimer's disease polygenic scores were associated independently with Alzheimer's disease and all-cause dementia incidence. Alzheimer's disease polygenic score was more strongly linked to incident Alzheimer's disease among women, while racial difference in all-cause dementia was explained by other factors including socio-economic status.

Pathways explaining racial/ethnic and socio-economic disparities in incident all-cause dementia among older US adults across income groups

Differential racial and socioeconomic disparities in dementia incidence across income groups and their underlying mechanisms remain largely unknown. A retrospective cohort study examining all-cause dementia incidence across income groups was conducted linking third National Health and Nutrition Examination Surveys (NHANES III) to Centers for Medicare and Medicaid Services-Medicare data over ≤26 y of follow-up (1988-2014). Cox regression and generalized structural equations models (GSEM) were constructed among adults aged≥60 y at baseline (N = 4,592). Non-Hispanic Black versus White (NHW) adults had higher risk of dementia in age and sex-adjusted Cox regression models (HR = 1.34, 95%CI: 1.15-1.55, P < 0.001), an association that was attenuated in the SES-adjusted model (HR = 1.15, 95%CI: 1.01-1.34, P = 0.092). SES was inversely related to dementia risk overall (per Standard Deviation, HR = 0.80, 95% CI:0.69-0.92, P = 0.002, Model 2), mainly within the middle-income group. Within the lowest and middle-income groups and in socio-economic status (SES)-adjusted models, Mexican American participants were at lower all-cause dementia risk compared with their NHW counterparts. GSEM models further detected 3 pathways explaining >55% of the total effect of SES on dementia risk (Total effect = -0.160 ± 0.067, p = 0.022), namely SES→LIFESTYLE→DEMENTIA (Indirect effect (IE) = -0.041 ± 0.014, p = 0.004), SES→LIFESTYLE→COGN→DEMENTIA (IE = -0.006 ± 0.001, p < 0.001), SES→COGN→DEMENTIA(IE = -0.040 ± 0.008, p < 0.001), with the last two remaining significant or marginally significant in the uppermost income groups. Diet and social support were among key lifestyle factors involved in socio-economic disparities in dementia incidence. We provide evidence for modifiable risk factors that may delay dementia onset differentially across poverty-income ratio groups, underscoring their importance for future observational and intervention studies.