Relationship between metabolic and vascular conditions and cognitive decline among older Mexican Americans

Methods and Early Recruitment of a Community-Based Study of Cognitive Impairment Among Mexican Americans and Non-Hispanic Whites: The BASIC-Cognitive Study

BACKGROUND

As the Mexican American (MA) population grows and ages, there is an urgent need to estimate the prevalence of cognitive impairment or dementia (CID), cognitive trajectories, and identify community resource needs. The Brain Attack Surveillance in Corpus Christi (BASIC)-Cognitive project is a population-based study to address these issues among older MAs and non-Hispanic whites (NHW) and their informal care providers.

OBJECTIVE

Present the methodology and initial recruitment findings for the BASIC-Cognitive project.

METHOD

Random, door-to-door case ascertainment is used in Nueces County, Texas, to recruit community-dwelling and nursing home residents ≥65 and informal care providers. Households are identified from a two-stage area probability sample, using Census data to aim for equal balance of MAs and NHWs. Individuals with cognitive screens indicative of possible CID complete neuropsychological assessment (Harmonized Cognitive Assessment Protocol from the Health and Retirement Study). Informal care providers complete comprehensive interview and needs assessment. Study pairs repeat procedures at 2-year follow-up. Asset and concept mapping are performed to identify community resources and study care providers' perceptions of needs for individuals with CID.

RESULTS

1,030 age-eligible households were identified, or 27% of households for whom age could be determined. 1,320 individuals were age-eligible, corresponding to 1.3 adults per eligible household. Initial recruitment yielded robust participation in the MA eligible population (60% of 689 individuals that completed cognitive screening).

CONCLUSION

The BASIC-Cognitive study will provide critical information regarding the prevalence of CID in MAs, the impact of caregiving, and allocation of community resources to meet the needs of this population.

Neuropsychiatric Symptoms by Cognitive Status for Mexican-Americans Aged 85 and Older

Few studies have investigated the relationship between neuropsychiatric symptoms (NPS) and cognitive status among older Mexican-American adults. Our objective was to describe the NPS of Mexican-Americans 85 years and older according to cognitive status. Data came from Wave 9 (conducted in 2016) of the Hispanic Established Populations for the Epidemiological Study of the Elderly. The final sample consisted of 381 care recipients ≥85 years. The 12-item Neuropsychiatric Inventory was administered to measure NPS among care recipients. Cognitive impairment was defined as a score of ≤18 on the Mini Mental State Exam or by clinical diagnosis of dementia as reported by the caregiver. Logistic regression models were used to estimate the average marginal effect (range = -1 to 1) of cognitive impairment on NPS, controlling for care-recipient characteristics. Overall, 259 (68.0%) participants had one or more NPS. Approximately 87% of care recipients with cognitive impairment had at least one NPS compared to 55.8% of those without cognitive impairment (p < .01). The predicted probability of having one or more NPS was 0.25% points (95% CI = 0.14-0.35) higher for participants with cognitive impairment than those without. NPS are present in the majority of very old Mexican American adults, particularly in those with cognitive impairment.

Health and social correlates of dementia in oldest-old Mexican-origin populations

INTRODUCTION

Substantial gaps in research remain across oldest-old ethnic populations while the burden of dementia increases exponentially with age among Mexican and Mexican American older adults.

METHODS

Prevalence and correlates of dementia among individuals ≥82 years of age were examined using two population-based cohort studies: The Mexican Health and Aging Study (MHAS, n = 1078, 2012) and the Hispanic Established Populations for the Epidemiologic Study of the Elderly (HEPESE, n = 735, 2012-2013). The analytic MHAS and HEPESE samples had an average age of 86.4 and 88.0 years, 1.2 and 1.8 women to men, and 2.7 and 5.1 average years of education, respectively.

RESULTS

We identified 316 (29.2%) and 267 (36.3%) cases of likely dementia in the MHAS and HEPESE cohorts, respectively. For Mexicans but not Mexican Americans, age-adjusted prevalence rates of likely dementia were higher in women than men. For both populations prevalence rates increased with age and decreased with education for Mexican Americans but not for Mexicans. In both populations, odds of likely dementia increased with age. Health insurance for the low-income was significantly associated with higher odds of likely dementia for Mexican American men and women and Mexican women but not men. Living in extended households increased the odds of likely dementia in women, but not in men for both studies. Multiple cardiovascular conditions increased the odds of likely dementia for Mexicans but not for Mexican Americans.

DISCUSSION

Our study provides evidence of the high burden of dementia among oldest-old Mexicans and Mexican Americans and its association with health and social vulnerabilities.

Representation of Older Latinxs in Cohort Studies at the Rush Alzheimer's Disease Center

The Rush Alzheimer's Disease Center (RADC) conducts 5 harmonized prospective clinical-pathologic cohort studies of aging - with 1 study, the Latino Core, focused exclusively on Latinxs, 2 studies consisting of mostly non-Latinx whites, and 2 studies of mostly non-Latinx blacks. This paper contextualizes the Latino Core within the other 4 harmonized RADC cohort studies. The overall aim of the paper is to provide information from the RADC, so that researchers can learn from our participants and procedures to better advance the science of Alzheimer's disease and related dementias in Latinxs. We describe an annual clinical evaluation that assesses risk factors for Alzheimer's dementia among older adults without known dementia at enrollment. As all RADC cohort studies offer brain donation as a part of research participation, we discuss our approach to brain donation and subsequent participant decision-making among older Latinxs. We also summarize baseline characteristics of older Latinxs across the 5 RADC cohort studies in relation to the baseline characteristics of non-Latinx blacks and non-Latinx whites. Finally, we outline challenges and considerations as well as potential next steps in cognitive aging research with older Latinxs.

Vascular Depression and Cognition in Mexican Americans

BACKGROUND

Mexican Americans are at increased risk of developing mild cognitive impairment (MCI) and Alzheimer's disease compared to non-Hispanic whites. This study sought to examine the relationship between vascular risk, depression, and cognition in Mexican American elders.

METHODS

Data from 470 (390 normal controls, 80 MCI patients) Mexican Americans enrolled in the Health and Aging Brain among Latino Elders (HABLE) study were used. The cardiovascular risk was assessed by the Framingham Risk Score. Cognition was assessed with a neuropsychological battery, and depression was assessed based on scores from the Geriatric Depression Scale (GDS). ANOVAs were utilized to determine the differences in neuropsychological scores of normal controls with and without depression and CVD risk (low vs. high). Follow-up logistic regression was conducted to determine MCI risk.

RESULTS

The results of this study indicated that comorbid depression and a high CVD risk were associated with poorer cognitive performance in Mexican Americans. Depressed women with high CVD risk were more likely to have executive dysfunction, language deficits, and poorer global cognition than nondepressed women with a high CVD risk. In Mexican American men, those with a high vascular risk and depression were more likely to have executive dysfunction and poorer immediate memory than the nondepressed high-risk group. Higher GDS scores (OR = 1.10; 95% CI 1.02-1.10, p = 0.001) and higher vascular risk scores (OR = 1.05; 95% CI 1.02-1.10, p = 0.001) significantly predicted MCI status in Mexican Americans.

CONCLUSION

The results of this study indicated that comorbid depression and a high CVD risk were associated with poorer cognitive performance and increased risk of MCI in Mexican Americans.

Cardiovascular disease risk factor burden and cognition: Implications of ethnic diversity within the Hispanic Community Health Study/Study of Latinos

OBJECTIVE

Hispanics/Latinos have some of the highest prevalence rates for cardiovascular disease risk factors, but stark differences exist by self-reported background. Cardiovascular disease risk factors negatively impact cognition in Hispanics/Latinos; less is known about these relationships by Hispanic/Latino backgrounds. We investigated cognitive associations with cardiovascular disease risk factor burden in a diverse cohort, the Hispanic Community Health Study/Study of Latinos.

METHODS

Baseline data from this observational study of cardiovascular disease and its antecedents was collected from 2008-2011. We included 7,121 participants 45-74 years old from Central American, Cuban, Dominican, Mexican, Puerto Rican, or South American backgrounds. Dichotomous indicators for hypertension, diabetes, hypercholesterolemia, obesity, and smoking were evaluated and totaled, with participants grouped by lowest (0-2), middle (3) or highest (4-5) burden. Cognitive testing included the Brief Spanish English Verbal Learning Test, letter fluency, and digit symbol substitution.

RESULTS

In separate fully-adjusted linear regression models, lower fluency and digit symbol substitution performance were restricted to the highest compared to the lowest burden group; whereas the middle burden group displayed impaired memory performance compared to the lowest burden group (p-values≤0.05). Background interacted with burden for learning and memory performance. That is, the association of burden level (i.e., lowest, middle, or highest) with cognitive performance was modified by background (e.g., Mexicans vs Cuban).

CONCLUSIONS

Hispanics/Latinos with higher levels of cardiovascular disease risk factor burden displayed lower levels of cognitive performance, with learning and memory performance modified by background.

Characteristics of Cognitively Normal Mexican-Americans with Cognitive Complaints

BACKGROUND

Subjective cognitive complaints in cognitively normal adults have been linked to later cognitive decline and dementia. Research on the characteristics of this group has been conducted on a variety of clinical and community-based populations. The current study focuses on the rapidly expanding population of Mexican-American elders.

OBJECTIVE

The objective of the study is the determination of characteristics of cognitively normal Mexican-Americans with cognitive complaints.

METHODS

Data on 319 cognitively normal participants in a large-scale community-based study of elderly Mexican-Americans (HABLE) were analyzed comparing those with cognitive complaints with those without on clinical characteristics, affective status, neuropsychological functioning, and proteomic markers.

RESULTS

Those expressing concern about cognitive decline scored lower on the MMSE, were more likely to have significantly more affective symptoms, higher levels of diabetic markers, poorer performance on attention and executive functioning, and a different pattern of inflammatory markers.

CONCLUSION

Although longitudinal research is needed to determine the impact of these differences on later cognition, possible targets for early intervention with Mexican-Americans were identified.

Blood Pressure and Hispanic/Latino Cognitive Function: Hispanic Community Health Study/Study of Latinos Results

BACKGROUND

Hispanics/Latinos are at increased risk for cardiovascular disease and cognitive decline and dementias. High blood pressure (BP) has been implicated in both stroke and dementias. Associations between BP and cognition among diverse Latinos are still unpublished.

OBJECTIVE

We examined associations between cognition and four BP based measures among diverse Hispanics/Latinos. We hypothesized that higher BP, particularly systolic pressure, and increased arterial stiffness (i.e., pulse pressure), would be associated with lower cognitive function.

METHODS

We used baseline (2008-2011) Hispanic Community Health Study/Study of Latinos (HCHS/SOL; n = 9,019; ages 45-74 years) data to examine cognition in relation to BP measures.

RESULTS

In age, sex, and education adjusted models, systolic, pulse, and mean arterial pressure were consistently negatively associated with executive function, psychomotor speed and sustained attention, verbal episodic learning and memory, speech fluency, and mental status measures. These associations were attenuated but remained statistically significant in fully adjusted models.

CONCLUSION

Among middle-aged and older diverse Hispanics/Latinos, we found modest but consistent associations between indicators of arterial stiffness, and compromised blood flow and lower cognitive function. Clinical management and public health interventions to raise awareness and enhance BP management beginning in midlife could reduce disparities and improve population health by reducing cognitive decline burdens.

Cardiovascular Risk Factors Are Correlated with Low Cognitive Function among Older Adults Across Europe Based on The SHARE Database

Increased life expectancy is associated with a high prevalence of chronic, non-communicable diseases including cognitive decline and dementia. The purpose of this study was to evaluate the prevalence of cognitive impairment using three cognitive abilities (verbal fluency, numeracy and perceived memory) and their association with cardiovascular risk factors in seniors across Europe. Data from participants in wave 4 of the SHARE (Survey of Health, Ageing, and Retirement in Europe) database was used. Cognitive performance in perceived memory, verbal fluency and numeracy was evaluated using simple tests and a memory complaints questionnaire. Clinical and sociodemographic variables were also studied for potential associations. Standardised prevalence rates of cognitive impairment based on age and gender were calculated by country. The prevalence of cognitive impairment was 28.02% for perceived memory, 27.89% for verbal fluency and 20.75% for numeracy throughout the 16 evaluated countries. Years of education, being a current or former smoker, number of chronic diseases, diabetes or hyperglycemia, heart attack and stroke were all independent variables associated with impairment in the three studied cognitive abilities. We also found independent associations between physical inactivity and verbal fluency and numeracy impairment, as well as hypertension and perceived memory impairment. Lower performance in the evaluated cognitive abilities and higher memory complaints are highly prevalent, have a heterogeneous distribution across Europe, and are associated with multiple factors, most of which are potentially preventable or treatable, especially cardiovascular risk factors.

Interactive relations of type 2 diabetes and abdominal obesity to cognitive impairment: A cross-sectional study in rural area of Xi'an in China

AIMS

Type 2 diabetes and obesity, which are frequently comorbid, have been associated with cognitive impairment. We aim to examine the potential modulating effect between obesity and diabetes on cognitive impairment.

METHODS

We recruited 865 adults (aged ≥55years) lived in a village of Xi'an in China from October 2014 to March 2015. All participants underwent biomedical and neuropsychological assessment. Relations of diabetes and abdominal obesity to cognitive impairment were examined in multiple regression models.

RESULTS

A total of 155 participants (17.9%) presented with the diagnosis of cognitive impairment. Diabetes or obesity alone wasn't significantly associated with cognitive impairment. Interaction analysis showed a significant interaction between abdominal obesity and diabetes on cognitive impairment. Stratified multivariate analysis revealed that the association between diabetes and cognitive impairment was positive in participants with abdominal obesity (OR 2.436, 95% CI 1.345-4.411, p=0.003, in diabetics with high WC, and OR 2.348, 95% CI 1.373-4.014, p=0.002, in diabetics with high WHR), but negative in those without abdominal obesity.

CONCLUSIONS

Type 2 diabetes interacts with abdominal obesity to be associated with an increased risk of cognitive impairment by more than two times.

Life-Space Mobility and Cognitive Decline Among Mexican Americans Aged 75 Years and Older

OBJECTIVES

To examine the association between life-space mobility and cognitive decline over a five-year period among older Mexican Americans.

DESIGN

Longitudinal study.

SETTING

Hispanic Established Population for the Epidemiologic Study of the Elderly survey conducted in the southwestern of United States (Texas, Colorado, Arizona, New Mexico, and California).

PARTICIPANTS

Four hundred thirty-two Mexican Americans aged 75 and older with normal or high cognitive function at baseline.

MEASUREMENTS

Socio-demographic factors, living arrangement, type of household, social support, financial strain, self-reported medical conditions, Mini-Mental State Examination (MMSE), depressive symptoms, activities of daily living (ADLs), and Short Physical Performance Battery. Life-space assessment (LSA) during the past 4 weeks was assessed during in-home interview. Scores ranged from 0 (daily restriction to the bedroom) to 120 (daily trips outside of their own town without assistance) and categorized as 0 to 20, 21 to 40, 41 to 60, 61 to 80, and 81 to 120. Because of the small sample size in the category of 81 to 120, the two highest categories were combined into a single group.

RESULTS

The mean LSA score and MMSE score of participants at baseline was 44.6 (Standard Deviation [SD], 20.7) and 25.7 (SD, 3.2), respectively. Mixed Model analyses showed that participants in the highest life-space category (≥61) experienced slower rates of cognitive decline over time compared to participants in the lowest category (0 to 20) (β = 1.03, Standard Error [SE] = 0.29, P = 0.0004), after adjusting for all covariates.

CONCLUSION

Greater life-space mobility at baseline was predictor of slower rates of cognitive decline over 5 years in older Mexican Americans.

Characterization of Alzheimer's Disease and Mild Cognitive Impairment in Older Adults in Panama

Research on age-related cognitive impairment is scarce in Central America. We report factors associated with cognitive impairment among a sample of older adults in Panama diagnosed with Alzheimer's disease (AD, n = 31), mild cognitive impairment (MCI, n = 43), or no cognitive impairment (controls, n = 185). Apolipoprotein E (ApoE) genotype was assessed in a subset of cases (n = 135). Age (OR = 2.53, 95% CI = 1.03-6.17) and ApoE ɛ4 (OR = 5.14, 95% CI = 2.11-12.52) were significantly related to cognitive impairment (AD/MCI combined). Results underscore the potential of genetic screening in Panama for identifying those at risk of dementia.