Dementia in older minority populations. Issues of prevalence, diagnosis, and treatment

Risk Factors Associated With Alzheimer Disease and Related Dementias by Sex and Race and Ethnicity in the US

Importance

Previous estimates suggested that 1 in 3 cases of Alzheimer disease and related dementia (ADRDs) in the US are associated with modifiable risk factors, the most prominent being physical inactivity, depression, and smoking. However, these estimates do not account for changes in risk factor prevalence over the past decade and do not consider potential differences by sex or race and ethnicity.

Objective

To update estimates of the proportion of ADRDs in the US that are associated with modifiable risk factors and to assess for differences by sex and race and ethnicity.

Design, Setting, and Participants

For this cross-sectional study, risk factor prevalence and communality were obtained from the nationally representative US Behavioral Risk Factor Surveillance Survey data from January 2018 to December 2018, and relative risks for each risk factor were extracted from meta-analyses. Data were analyzed from December 2020 to August 2021. Respondents included 378 615 noninstitutionalized adults older than 18 years. The number before exclusion was 402 410. Approximately 23 795 (~6%) had missing values on at least 1 of the variables of interest.

Exposures

Physical inactivity, current smoking, depression, low education, diabetes, midlife obesity, midlife hypertension, and hearing loss.

Main Outcomes and Measures

Individual and combined population-attributable risks (PARs) associated with ADRDs, accounting for nonindependence between risk factors.

Results

Among 378 615 individuals, 171 161 (weighted 48.7%) were male, and 134 693 (weighted 21.1%) were 65 years and older. Race and ethnicity data were self-reported and defined by the US Behavioral Risk Factor Surveillance System Data; 6671 participants (weighted 0.9%) were American Indian and Alaska Native, 8043 (weighted 5.1%) were Asian, 29 956 (weighted 11.7%) were Black, 28 042 (weighted 16.0%) were Hispanic (any race), and 294 394 (weighted 64.3%) were White. Approximately 1 in 3 of ADRD cases (36.9%) in the US were associated with 8 modifiable risk factors, the most prominent of which were midlife obesity (17.7%; 95% CI, 17.5-18.0), physical inactivity (11.8%; 95% CI, 11.7-11.9), and low educational attainment (11.7%; 95% CI, 11.5-12.0). Combined PARs were higher in men (35.9%) than women (30.1%) and differed by race and ethnicity: American Indian and Alaska Native individuals, 39%; Asian individuals, 16%; Black individuals, 40%; Hispanic individuals (any race), 34%; and White individuals, 29%. The most prominent modifiable risk factors regardless of sex were midlife obesity for American Indian and Alaska Native individuals, Black individuals, and White individuals; low education for Hispanic individuals; and physical inactivity for Asian individuals.

Conclusions and Relevance

The findings suggest that risk factors associated with ADRDs have changed over the past decade and differ based on sex and race and ethnicity. Alzheimer risk reduction strategies may be more effective if they target higher-risk groups and consider current risk factor profiles.

Is Acculturation Associated with the Cognitive Performance of Older Hispanics?

BACKGROUND

Hispanics in the United Statues are disproportionately affected by Alzheimer's disease and related dementias. Little is known about the impact of acculturation on cognitive performance.

OBJECTIVE

This study examined the association between acculturation and cognitive performance among older Hispanics.

METHODS

We analyzed cross-sectional data of 616 Hispanic participants in the National Health and Nutrition Examination Survey (NHANES) 2011-2014 [average age = 67.15 years, %Female = 51.46, %less than high-school graduate = 52.60]. Cognitive performance was measured by two neuropsychological tests: Animal Fluency Test (AFT) and Digit Symbol Substitution Test (DSST). We used two single-item proxy measures to quantify acculturation: nativity status (non-US-born residing <  15 years in the US (low acculturation), non-US-born residing ≥15 years in the US, and US-born (high acculturation)); and language acculturation (only/mostly Spanish (low acculturation), Spanish and English, only/mostly English (high acculturation)). We used adjusted linear regression to evaluate associations between acculturation and cognitive performance.

RESULTS

Results indicated poorer cognitive performance among the low-acculturated groups for both nativity and linguistic measures. Participants who were non-US-born living ≥15 years (p = 0.02) and speaking only/mostly Spanish or Spanish and English (p = 0.01 and 0.006 respectively) had significantly lower AFT scores compared to US-born and only/mostly English-speaking groups. Participants who were non-US-born living <  15 years (p <  0.0001) or non-US-born living ≥15 years (p <  0.0001) and speaking only/mostly Spanish (p = 0.0008) scored lower on the DSST than the US-born and only/mostly English-speaking participants.

CONCLUSION

In summary, low acculturation is associated with poorer cognitive performance among older Hispanics. Acculturation might be an important attribute to help understand cognitive decline and dementias among Hispanics.

A Systematic Review of Neuropsychological Tests for the Assessment of Dementia in Non-Western, Low-Educated or Illiterate Populations

OBJECTIVE

Neuropsychological tests are important instruments to determine a cognitive profile, giving insight into the etiology of dementia; however, these tests cannot readily be used in culturally diverse, low-educated populations, due to their dependence upon (Western) culture, education, and literacy. In this review we aim to give an overview of studies investigating domain-specific cognitive tests used to assess dementia in non-Western, low-educated populations. The second aim was to examine the quality of these studies and of the adaptations for culturally, linguistically, and educationally diverse populations.

METHOD

A systematic review was performed using six databases, without restrictions on the year or language of publication.

RESULTS

Forty-four studies were included, stemming mainly from Brazil, Hong Kong, Korea, and considering Hispanics/Latinos residing in the USA. Most studies focused on Alzheimer's disease (n = 17) or unspecified dementia (n = 16). Memory (n = 18) was studied most often, using 14 different tests. The traditional Western tests in the domains of attention (n = 8) and construction (n = 15), were unsuitable for low-educated patients. There was little variety in instruments measuring executive functioning (two tests, n = 13), and language (n = 12, of which 10 were naming tests). Many studies did not report a thorough adaptation procedure (n = 39) or blinding procedures (n = 29).

CONCLUSIONS

Various formats of memory tests seem suitable for low-educated, non-Western populations. Promising tasks in other cognitive domains are the Stick Design Test, Five Digit Test, and verbal fluency test. Further research is needed regarding cross-cultural instruments measuring executive functioning and language in low-educated people.

Disparities in Nursing Home Use and Quality Among African American, Hispanic, and White Medicare Residents With Alzheimer's Disease and Related Dementias

Objective: This article examines differences in nursing home use and quality among Medicare beneficiaries, in both Medicare Advantage and fee-for-service, newly admitted to nursing homes with Alzheimer's disease and related dementias (ADRD). Method: Retrospective, national, population-based study of Medicare residents newly admitted to nursing homes with ADRD by race and ethnic group. Our analytic sample included 1,302,099 nursing home residents-268,181 with a diagnosis of ADRD-in 13,532 nursing homes from 2014. Results: We found that a larger share of Hispanic Medicare residents that are admitted to nursing homes have ADRD compared with African American and White beneficiaries. Both Hispanics and African Americans with ADRD received care in segregated nursing homes with fewer resources and lower quality of care compared with White residents. Discussion: These results have implications for targeted efforts to achieve health care equity and quality improvement efforts among nursing homes that serve minority patients.

Relationship between Cognitive Performance and Measures of Neurodegeneration among Hispanic and White Non-Hispanic Individuals with Normal Cognition, Mild Cognitive Impairment, and Dementia

OBJECTIVES

The aim of this study was to determine the presence and severity of potential cultural and language bias in widely used cognitive and other assessment instruments, using structural MRI measures of neurodegeneration as biomarkers of disease stage and severity.

METHODS

Hispanic (n=75) and White non-Hispanic (WNH) (n=90) subjects were classified as cognitively normal (CN), amnestic mild cognitive impairment (aMCI) and mild dementia. Performance on the culture-fair and educationally fair Fuld Object Memory Evaluation (FOME) and Clinical Dementia Rating Scale (CDR) between Hispanics and WNHs was equivalent, in each diagnostic group. Volumetric and visually rated measures of the hippocampus entorhinal cortex, and inferior lateral ventricles (ILV) were measured on structural MRI scans for all subjects. A series of analyses of covariance, controlling for age, depression, and education, were conducted to compare the level of neurodegeneration on these MRI measures between Hispanics and WNHs in each diagnostic group.

RESULTS

Among both Hispanics and WNH groups there was a progressive decrease in volume of the hippocampus and entorhinal cortex, and an increase in volume of the ILV (indicating increasing atrophy in the regions surrounding the ILV) from CN to aMCI to mild dementia. For equivalent levels of performance on the FOME and CDR, WNHs had greater levels of neurodegeneration than did Hispanic subjects.

CONCLUSIONS

Atrophy in medial temporal regions was found to be greater among WNH than Hispanic diagnostic groups, despite the lack of statistical differences in cognitive performance between these two ethnic groups. Presumably, unmeasured factors result in better cognitive performance among WNH than Hispanics for a given level of neurodegeneration. (JINS, 2018, 24, 176-187).

Increased Reporting Accuracy of Alzheimer Disease Symptoms in Caribbean Hispanic Informants

INTRODUCTION

Informant report of symptoms is essential for diagnosing and characterizing Alzheimer disease (AD). Differences in the perception and experience of dementia across ethnicities may influence informant report. Understanding such differences is critical given that among those with AD, Hispanics are disproportionately affected.

METHODS

Cross-sectional analyses examined informant report of cognitive and functional symptoms in mild AD across white (n=107) and Caribbean Hispanic (n=71) informants. To explore its accuracy, informant report of symptoms was compared against objective measures of patient performance.

RESULTS

Adjusted analyses revealed Hispanics reported more symptoms than white informants. Informant report of symptoms was inversely correlated with patients' global cognition in both ethnic groups. Only Hispanic report of symptoms was significantly associated with memory and language performance.

DISCUSSION

Informant report of symptoms was associated with patients' global cognition, reflecting relatively accurate informant reports in both ethnic groups, and was stronger in Hispanics when examining memory and language. Such differences may reflect cultural caregiving practices and perceptions of dementia, having implications for diagnosis and treatment.

Racial/Ethnic Differences in Trajectories of Cognitive Function in Older Adults

OBJECTIVE

The objective of this study is to (a) examine racial/ethnic differences in trajectories of cognitive function and (b) evaluate the role of education and health behaviors (physical activity [PA] and smoking) as mediators of racial/ethnic differences in the rate of decline in cognitive function in older adults.

METHOD

Data for this study came from the Health and Retirement Study ( n = 3,424). Hierarchical linear models were used to define the trajectory of cognitive function between 2002 and 2008. Participants were classified based on PA as non-vigorously active, intermittent vigorously active, and consistently vigorously active.

RESULTS

After adding education, the Hispanic's and Black's disparities in cognitive performance were slightly attenuated (Hispanics, β = -1.049, p < .001; Blacks, β = -3.397, p < .001) but were still different from Whites. Smoking was not associated with the cognition intercept or rate of decline.

DISCUSSION

We found education had a partial mediating effect on racial differences in levels of cognition but not on the rate of change over time.

Aluminum, the genetic apparatus of the human CNS and Alzheimer's disease (AD)

The genomes of eukaryotes orchestrate their expression to ensure an effective, homeostatic and functional gene signaling program, and this includes fundamentally altered patterns of transcription during aging, development, differentiation and disease. These actions constitute an extremely complex and intricate process as genetic operations such as transcription involve the very rapid translocation and polymerization of ribonucleotides using RNA polymerases, accessory transcription protein complexes and other interrelated chromatin proteins and genetic factors. As both free ribonucleotides and polymerized single-stranded RNA chains, ribonucleotides are highly charged with phosphate, and this genetic system is extremely vulnerable to disruption by a large number of electrostatic forces, and primarily by cationic metals such as aluminum. Aluminum has been shown by independent researchers to be particularly genotoxic to the genetic apparatus, and it has become reasonably clear that aluminum disturbs genetic signaling programs in the CNS that bear a surprising resemblance to those observed in Alzheimer's disease (AD) brain. This paper will focus on a discussion of two molecular-genetic aspects of aluminum genotoxicity: (1) the observation that micro-RNA (miRNA)-mediated global gene expression patterns in aluminum-treated transgenic animal models of AD (Tg-AD) strongly resemble those found in AD; and (2) the concept of "human biochemical individuality" and the hypothesis that individuals with certain gene expression patterns may be especially sensitive and perhaps predisposed to aluminum genotoxicity.

Diversity and disparity in dementia: the impact of ethnoracial differences in Alzheimer disease

Debate exists regarding differences in the prevalence of Alzheimer disease (AD) in African Americans and Hispanics in the United States, with some evidence suggesting that the prevalence of AD may be considerably higher in these groups than in non-Hispanic whites. Despite this possible disparity, patients of minority ethnoracial groups often receive delayed diagnosis or inadequate treatment for dementia. This review investigates these disparities by conceptualizing the dementia disease process as a product of both biological and cultural factors. Ethnoracial differences in biological risk factors, such as genetics and cardiovascular disease, may help to explain disparities in the incidence and prevalence of AD, whereas race-specific cultural factors may impact diagnosis and treatment. Cultural factors include differences in perceptions about what is normal aging and what is not, lack of adequate access to medical care, and issues of trust between minority groups and the medical establishment. The diagnosis of AD in diverse populations may also be complicated by racial biases inherent in cognitive screening tools widely used by clinicians, but controlling for literacy level or using savings scores in psychometric analyses has the potential to mitigate these biases. We also suggest that emerging biomarker-based diagnostic tools may be useful in further characterizing diverse populations with AD. Recognizing the gap in communication that exists between minority communities and the medical research community, we propose that education and outreach are a critical next step in the effort to understand AD as it relates to diverse populations.

Using the Barnes Language Assessment with older ethnic minority groups

OBJECTIVE

There are many issues concerning the assessment of older people from ethnic minority groups, the most significant being the language barrier experienced by those whose English is an additional language (EAL). This study aimed to test the hypothesis that EAL participants would score less well than those with English as a first language (EFL) on the sub-tests of the Barnes Language Assessment (BLA), elucidate the reasons for any such differences and discuss the implications.

METHODS

The Barnes Language Assessment (BLA) is an accurate tool providing information about expected patterns of language in different dementia syndromes. This study compares the performance of EAL participants with EFL participants. The BLA was administered to 144 participants, divided into sub-groups with respect to age, gender and educational background, none of whom had a working diagnosis of dementia.

RESULTS

Results suggest that EAL speakers performed less well compared to EFL speakers when other variables were matched. Significantly better BLA scores, at the one percent level, were found in both EAL and EFL groups with higher educational achievement for eight of the 15 sub-tests.

CONCLUSION

Differences were found in performance on the BLA between EAL and EFL participants. The degree of difference between EAL and EFL speakers decreased as educational achievement rose. The consequences of these findings for service delivery and the problems of recruitment of older EAL participants are discussed.

African American caregivers

Despite the significance of an early diagnosis of Alzheimer's disease (AD), African Americans are diagnosed in later stages of the disease and present with greater cognitive impairment at the time of diagnosis when compared to Euro-Americans. To this end, there exists a paucity of research on diagnostic pathways among African Americans with dementia. More specifically, few studies have explored help-seeking pathways from the initial manifestation of symptoms until an actual diagnosis of Alzheimer's disease was received from the perspective of African American caregivers. Thus, the present study examined the retrospective experiences of 17 African American caregivers who were given a diagnosis of Alzheimer's disease for a family member with dementia. Participants completed face-to-face semi-structured interviews. Study findings revealed a complex interplay between the patient with dementia, entities that comprise their social support network, and clinicians.

Stigmatization in Alzheimer's disease research on African American elders

Stigmatization in research sustains the spread of the silent epidemic of Alzheimer's disease (AD) in African American populations. Researchers use stereotypes and inappropriate assumptions to select a paradigm to examine the symptoms of AD. This paradigm fails to encompass the symptoms as manifested by African American elders. Yet, stigmatization can be minimized by recognizing the genetic heterogeneity of the symptoms within the general population, especially those manifested by African American elders. Thus, researchers can utilize pioneering genetic analyses to identify other paradigms critical in the assessment and proactive treatment of the symptoms of AD needed for this vulnerable population.

Frequency of Alzheimer's disease and other dementias in a community outreach sample of Hispanics

OBJECTIVES

To determine the proportion of Alzheimer's disease (AD) and other dementia types in a community sample of Hispanics.

DESIGN

This is a descriptive diagnostic study of a nonrandom community outreach sample utilizing established criteria for the diagnosis of dementia type. Recruitment involved direct community outreach with diagnostic evaluations conducted at a university-affiliated outpatient clinic.

SETTING

Hispanic Neuropsychiatric and Memory Research Clinic at the Olive View-UCLA Medical Center in Sylmar, California.

PARTICIPANTS

One hundred community-dwelling Hispanics age 55 and older without prior diagnosis or treatment of their cognitive symptoms.

MEASUREMENTS

Each subject underwent a complete medical diagnostic evaluation, in Spanish, including neuropsychological tests, neurological examination, laboratory tests, and brain imaging (computed tomography or magnetic resonance imaging) to establish dementia type. Presence of dementia was established according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. Diagnosis for probable or possible AD and vascular dementia (VascD) was established using criteria from the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association for probable AD and by research criteria from the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences for VascD, respectively. Frontotemporal dementia was diagnosed using recommendations set forth by the Lund and Manchester groups.

RESULTS

Subjects were poor, with low acculturation levels despite long years of U.S. residence. Forty percent of subjects had had undiagnosed cognitive symptoms for 3 or more years. Of those demented, 38.5% had AD and 38.5% met criteria for VascD. The best predictors of VascD were hypertension and cerebrovascular disease, whereas apolipoprotein E4 allele best predicted AD. Other forms of dementia were also present. Twenty percent of the sample was clinically depressed but not demented.

CONCLUSIONS

In comparison with data from predominantly white populations, our proportion of AD cases was lower and that of VascD cases was considerably higher than anticipated. The percentage of clinically depressed older individuals was also high. These findings could have implications for differential cultural and genetic risk factors for dementia among diverse ethnic/racial groups. Further studies are needed to obtain accurate prevalence estimates of dementing disorders among the different U.S. Hispanic populations.

Use of the Iowa Self-Assessment Inventory with older hospitalized patients

This study examined the utility of the Iowa Self-Assessment Inventory (ISAI) as a multidimensional screening tool for older adults in the acute care hospital setting. A sample of 98 patients age 60 and older were administered the ISAI, the Short Geriatric Depression Scale, and the Mini-Mental State Examination. The findings suggest the ISAI is useful for screening for depression but does not detect differences in cognition. However, qualitative data and literature review support the continued search for a holistic, humanistic screening tool to increase the quality and effectiveness of patient care.