Late-life Cognitive Impairment Research Articles

Addressing Practice Effects in Population-Based Studies of Trends in Late-Life Dementia and Cognitive Impairment.

Addressing Practice Effects in Population-Based Studies of Trends in Late-Life Dementia and Cognitive Impairment.

The association between BMI and cognition in India: data from the Longitudinal Aging Study in India (LASI)

BackgroundHigh body-mass index (BMI) is an established risk factor for late-life cognitive impairment and dementia, but most evidence comes from high-income contexts. Existing evidence from cross-sectional data in low- and middle-income settings is inconsistent, and many studies do not adequately address potential sources of bias.MethodsWe used data from Wave 1 of the Longitudinal Aging Study in India (LASI) (analytic N = 56,753) to estimate the association between BMI categories and cognitive functioning among older adults aged 45 + years using survey-weighted linear regression models stratified by gender and controlling for potential confounders including demographic factors, socio-economic status (SES) characteristics, and health-related behaviors. To probe potential sources of bias, including residual confounding and reverse causation, we used weighting and trimming methods, sample restriction, and explored effect modification.ResultsIn fully adjusted models, relative to normal BMI underweight BMI was associated with lower cognitive scores (Men: -0.16 SD difference, 95% CI -0.18, -0.13; Women: -0.12 SD, -0.15, -0.10). Overweight and obesity were associated with higher cognitive scores in both men (overweight: 0.09; 0.07, 0.12, obese: 0.10; 0.05, 0.15) and women (overweight: 0.09; 0.07–0.12, obese: 0.12; 0.08–0.15). Estimates were similar after weighting and trimming but were attenuated after excluding those with low cognition (≥1 SD below the mean relative to those with similar demographic characteristics). Positive associations between overweight and obese BMI and cognition were attenuated or null in those living in urban settings and those with higher levels of educational attainment.ConclusionsUnderweight BMI is a risk factor for poor cognitive outcomes in adults 45 years and older and may be indicative of poor nutritional status and life-course disadvantage in India. In tandem with existing literature, supplemental analyses and effect modification results indicate that unmeasured confounding and reverse causation may explain the observed positive associations between overweight and obese BMI and cognitive functioning from cross-sectional studies in low- and middle-income settings. Future data with longitudinal follow-up will be helpful to further disentangle biases.

Spatiotemporal Gait Characteristics and Neuropsychological Performance in Midlife

Abstract Background Midlife risk factors such as Type 2 Diabetes Mellitus (T2DM) confer a significantly increased risk of cognitive impairment in later life, with executive function, memory and attention domains often affected first. Spatiotemporal gait characteristics are increasingly recognised as biomarkers of neurocognitive function and later dementia risk. Methods Using an automated walkway, 24 spatiotemporal gait parameters were examined across 5 domains of gait previously linked to cognitive function on usual-pace, maximal-pace, and cognitive dual-task gait conditions. Neurocognitive function was measured using a neuropsychological assessment battery. Linear regression was used assess the relationship between each gait parameter across the three walks and cognitive function. Results 102 middle-aged adults underwent assessment, 65 with uncomplicated T2DM (57.5 ± 8.0 years; 40% female) and 37 healthy controls (57.0 ± 8.3 years; 62.1% female). T2DM was associated with significant changes in gait phases and rhythm domains at usual-pace, and greater gait variability observed during maximal-pace and dual-task. In the overall cohort, both gait pace and rhythm domains were associated with memory and executive function during usual pace walking. At maximal-pace, gait pace parameters were associated with reaction time and delayed memory. During the cognitive dual-task, associations between gait variability and delayed memory and executive function were observed. Associations persisted following covariate adjustment and did not differ by T2DM status. Conclusion This supports the use of spatiotemporal gait as an integrative biomarker of neurocognitive function in otherwise healthy middle-aged individuals. Discrete associations were seen between both differing gait tasks and gait domains with domain-specific neuropsychological performance. Employing both maximal-pace and dual-task paradigms, in addition to single-task usual-pace gait, may be important in cognitively unimpaired populations with risk factors for later cognitive decline - with the aim of identifying individuals who may benefit most from potential preventative interventions.

The influence of widowhood and social engagement on cognitive impairment among Chinese older adults and factors mediating their association.

Prior studies exploring the impact of widowhood on cognitive impairment in later life have been focussed on the USA and Europe. We aimed to explore the mediating role of social engagement, health behaviours, and subjective well-being in the association between widowhood and cognitive impairment in the Chinese population. We conducted a study on 7796 older individuals enrolled in the 2018 wave of the Chinese Longitudinal Health Longevity Study. We used logistic regression models to analyse the impact of widowhood on cognitive health among older adults and performed mediation analysis to determine possible mediating factors in this relationship. Widows and widowers had a higher risk of having cognitive impairment than married older adults (95% confidence interval (CI) = 1.312, 2.279). The results from structural equation modelling (SEM) provided a good fit to the observed data (χ2 = 24.909; P = 0.00) and indicated that the effect of widowhood on cognitive impairment was partially mediated by social engagement, lifestyle behaviours, and subjective well-being (β = 0.075; P < 0.01). Our findings contribute to existing research on the mechanisms underlying the association between widowhood and cognitive impairment among older individuals, suggesting a need for policies targeted at the specific needs of this vulnerable population, such as the maintenance of social interactions, adoption of a healthy lifestyle, improvement of subjective well-being, and provision of necessary support systems.

Daily cannabis use and cognitive impairment in community residents aged 50 and over

ABSTRACT Background Cannabis use is associated with cognitive dysfunction in younger adults, but little is known about its role as a risk factor for dementia. This study aimed to explore the association between daily cannabis use and cognitive impairment in a cohort study of middle-aged and older people at risk of dementia. Methods Sample drawn from a cross-sectional study involving 15,582 people aged 50 and over from PROTECT study. Lifetime heavy cannabis use was defined by daily use. Results A total of 4203 (27%) participants reported lifetime cannabis use, of whom 4097 responses to frequency of use were obtained. Among them, 259 participants reported lifetime daily, and 3838 reported less than daily use. Those with lifetime daily cannabis use were more likely than those without to be unmarried, of lower educational attainment, and current or past tobacco smokers. They were more likely to show moderate or moderate-to-severe anxiety and depression. Baseline lifetime daily cannabis use was also associated with improved verbal reasoning but not with change in other cognitive scores. Conclusions Given improved verbal reasoning in people with daily lifetime cannabis use, the relationship between quantity and frequency of cannabis use and cognitive impairment in later life warrants further examination.

Physical activity initiated from midlife on risk of dementia and cognitive impairment: The Health and Retirement Study.

Physical activity is associated with lower risk of dementia and cognitive impairment, but existing randomized controlled trials have shown conflicting results. As cognitive decline occurs decades before the onset of dementia, physical activity interventions initiated in late life may have missed the potential window for prevention. An ideal trial of physical activity initiated from midlife and lasts till incident dementia and cognitive impairment in late life is not feasible. We aimed to estimate the effectiveness of a hypothetical physical activity intervention initiated from midlife on reducing dementia and cognitive impairment by emulating target trials using observational data. The Health and Retirement Study was used to emulate target trials among noninstitutionalized participants aged 45 to 65 years with normal cognition who were physically inactive in the previous 2 years. Cognitive status was determined based on Langa-Weir classification of cognitive function (including immediate and delayed word recall tests, serial sevens subtraction, counting backward). Individuals were categorized as initiating physical activity or not, based on the self-reported physical activity. Intention-to-treat and per-protocol analysis were conducted with pooled logistic regression models with inverse-probability of treatment and censoring weights to estimate risk ratios (RRs), and 95% confidence intervals (95% CIs) were calculated with 200 sets of bootstrapping. Among 1505 participants (average age 57.6 ± 4.8 years, 67% women, 76.5% White), 72 cases of dementia and 409 cases of cognitive impairment occurred. After 12 years of follow-up, physical activity reduced dementia (RR = 0.70, 95% CI: 0.43, 0.99) for intention-to-treat analysis, and reduced dementia (RR = 0.51, 95% CI: 0.19, 0.99) and cognitive impairment (RR = 0.77, 95% CI: 0.61, 0.92) for per-protocol analysis. No significant reduction was found among older adults. Physical activity initiated during midlife may reduce dementia and cognitive impairment in late life, which highlights the importance of preventing cognitive outcomes at an earlier stage of life.

Source-Specific Air Pollution and Loss of Independence in Older Adults Across the US

Air pollution is a recognized risk factor associated with chronic diseases, including respiratory and cardiovascular conditions, which can lead to physical and cognitive impairments in later life. Although these losses of function, individually or in combination, reduce individuals' likelihood of living independently, little is known about the association of air pollution with this critical outcome. To investigate associations between air pollution and loss of independence in later life. This cohort study was conducted as part of the Environmental Predictors Of Cognitive Health and Aging study and used 1998 to 2016 data from the Health and Retirement Study. Participants included respondents from this nationally representative, population-based cohort who were older than 50 years and had not previously reported a loss of independence. Analyses were performed from August 31 to October 15, 2023. Mean 10-year pollutant concentrations (particulate matter less than 2.5 μm in diameter [PM2.5] or ranging from 2.5 μm to 10 μm in diameter [PM10-2.5], nitrogen dioxide [NO2], and ozone [O3]) were estimated at respondent addresses using spatiotemporal models along with PM2.5 levels from 9 emission sources. Loss of independence was defined as newly receiving care for at least 1 activity of daily living or instrumental activity of daily living due to health and memory problems or moving to a nursing home. Associations were estimated with generalized estimating equation regression adjusting for potential confounders. Among 25 314 respondents older than 50 years (mean [SD] baseline age, 61.1 [9.4] years; 11 208 male [44.3%]), 9985 individuals (39.4%) experienced lost independence during a mean (SD) follow-up of 10.2 (5.5) years. Higher exposure levels of mean concentration were associated with increased risks of lost independence for total PM2.5 levels (risk ratio [RR] per 1-IQR of 10-year mean, 1.05; 95% CI, 1.01-1.10), PM2.5 levels from road traffic (RR per 1-IQR of 10-year mean, 1.09; 95% CI, 1.03-1.16) and nonroad traffic (RR per 1-IQR of 10-year mean, 1.13; 95% CI, 1.03-1.24), and NO2 levels (RR per 1-IQR of 10-year mean, 1.05; 95% CI, 1.01-1.08). Compared with other sources, traffic-generated pollutants were most consistently and robustly associated with loss of independence; only road traffic-related PM2.5 levels remained associated with increased risk after adjustment for PM2.5 from other sources (RR per 1-IQR increase in 10-year mean concentration, 1.10; 95% CI, 1.00-1.21). Other pollutant-outcome associations were null, except for O3 levels, which were associated with lower risks of lost independence (RR per 1-IQR increase in 10-year mean concentration, 0.94; 95% CI, 0.92-0.97). This study found that long-term exposure to air pollution was associated with the need for help for lost independence in later life, with especially large and consistent increases in risk for pollution generated by traffic-related sources. These findings suggest that controlling air pollution could be associated with diversion or delay of the need for care and prolonged ability to live independently.

Discrete Relationships between Spatiotemporal Gait Characteristics and Domain-Specific Neuropsychological Performance in Midlife.

Midlife risk factors such as type 2 diabetes mellitus (T2DM) confer a significantly increased risk of cognitive impairment in later life with executive function, memory, and attention domains often affected first. Spatiotemporal gait characteristics are emerging as important integrative biomarkers of neurocognitive function and of later dementia risk. We examined 24 spatiotemporal gait parameters across five domains of gait previously linked to cognitive function on usual-pace, maximal-pace, and cognitive dual-task gait conditions in 102 middle-aged adults with (57.5 ± 8.0 years; 40% female) and without (57.0 ± 8.3 years; 62.1% female) T2DM. Neurocognitive function was measured using a neuropsychological assessment battery. T2DM was associated with significant changes in gait phases and rhythm domains at usual pace, and greater gait variability observed during maximal pace and dual tasks. In the overall cohort, both the gait pace and rhythm domains were associated with memory and executive function during usual pace. At maximal pace, gait pace parameters were associated with reaction time and delayed memory. During the cognitive dual task, associations between gait variability and both delayed memory/executive function were observed. Associations persisted following covariate adjustment and did not differ by T2DM status. Principal components analysis identified a consistent association of slower gait pace (step/stride length) and increased gait variability during maximal-pace walking with poorer memory and executive function performance. These data support the use of spatiotemporal gait as an integrative biomarker of neurocognitive function in otherwise healthy middle-aged individuals and reveal discrete associations between both differing gait tasks and gait domains with domain-specific neuropsychological performance. Employing both maximal-pace and dual-task paradigms may be important in cognitively unimpaired populations with risk factors for later cognitive decline-with the aim of identifying individuals who may benefit from potential preventative interventions.

Shedding Light on the Effects of Blood Pressure on Cognitive Decline and Dementia Risk by Way of Neurobiological Evidence.

Midlife cerebrovascular risk factors increase risk of late life cognitive impairment and dementia, while their presence in patients with dementia may lead to cognitive improvement or stabilization in late life. Defining the best measure of blood pressure (BP) to be associated with cognitive decline remains debatable, also due to possible bidirectionality. BP variability, pulse pressure, systolic and diastolic BP have been associated with cognitive status, dementia risk and Alzheimer's disease biomarkers. Proper BP control notwithstanding, BP variability increases risk for pathophysiological change in the Alzheimer's disease continuum, implying the need for selection of anti-hypertensive drugs with neurobiological evidence of benefits.

Does losing family members in midlife matter for late-life mental and cognitive health? A longitudinal study of older Swedes spanning 30 years

Objectives Mental and cognitive health is crucial to ensure well-being in older age. However, prolonged periods of stress, grief, and bereavement might compromise mental health balance, leading to profound changes. This study investigated the sex-stratified associations between midlife bereavement experiences (e.g. sibling loss, spousal loss, and multiple losses) and late-life depression (LLD) and cognitive impairment. Method Linked data from the Swedish Level-of-Living Survey and the Swedish Panel Study of Living Conditions of the Oldest Old (SWEOLD) were used. Multiple logistic regressions were performed to examine the associations between midlife bereavement and LLD (n = 1078) and cognitive impairment (n = 995), separately. Results Sibling loss and multiple losses in midlife were associated with lower odds of LLD, especially among women. Among men, sibling loss in midlife was associated with lower odds of cognitive impairment, while the experience of two losses among women suggested an increased (but non-significant) risk of cognitive impairment. Interaction analyses did not show significant effects between bereavement and gender on LLD and cognitive impairment. Conclusion Midlife bereavement might have gendered implications on LLD and cognitive impairment, but associations need to be confirmed by well-powered studies. Further research is warranted to elucidate the association between multiple midlife losses and reduced LLD risk.

General cognitive ability in high school, attained education, occupational complexity, and dementia risk.

We address the extent to which adolescent cognition predicts dementia risk in later life, mediated by educational attainment and occupational complexity. Using data from Project Talent Aging Study (PTAS), we fitted two structural equation models to test whether adolescent cognition predicts cognitive impairment (CI) and Ascertain Dementia 8 (AD8) status simultaneously (NCognitive Assessment=2477) and AD8 alone (NQuestionnaire=6491) 60 years later, mediated by education and occupational complexity. Co-twin control analysis examined 82discordant pairs for CI/AD8. Education partially mediated the effect of adolescent cognition on CI in the cognitive assessment aample and AD8 inthe questionnaire sample (Ps<0.001). Within twin pairs, differences in adolescent cognition were small, but intrapair differences in education predicted CI status. Adolescent cognition predicted dementia risk 60 years later, partially mediated through education. Educational attainment, but not occupational complexity, contributes to CI risk beyond its role as a mediator of adolescent cognition, further supported by the co-twin analyses. Project Talent Aging Study follows enrollees from high school for nearly 60 years. General cognitive ability in high school predicts later-life cognitive impairment. Low education is a risk partially due to its association with cognitive ability.

Discrimination and Cognition in Midlife Black Women: The Roles of Social Support and Spirituality.

Black women are at high risk for discrimination and cognitive impairment in late life. It is not known if discrimination is a risk factor for cognitive decline in Black women and if so, what factors are protective against the adverse cognitive effects of discrimination. Using the biopsychosocial model of gendered racism, we determined if discrimination is associated with poorer cognition in midlife Black women and if social support and/or spirituality would protect against the deleterious effects of discrimination on cognition. Participants were midlife Black women (N = 669) from the Study of Women's Health Across the Nation. Discrimination was measured by the Everyday Discrimination scale. Cognitive outcomes included episodic memory, processing speed, and working memory. Total social support, emotional support, instrumental support, and spirituality were assessed as protective factors. Contrary to expectations, structural equation modeling indicated that discrimination was associated with better immediate recall. For women with more emotional support, greater discrimination was associated with better immediate recall than for women with lower emotional support. Spirituality was not a significant moderator in the association between discrimination and cognition. Discrimination had unexpected positive associations with learning and attention-based cognitive skills for midlife Black women. Discrimination might enhance vigilance, which could be facilitated by higher levels of emotional support. There is an opportunity for clinical and public health interventions for cognitive health and discrimination focused on Black women to better incorporate emotional support as a coping resource.

BOTH COGNITIVE IMPAIRMENT AND DEPRESSION MAY INCREASE THE RISK OF POOR MUSCLE FUNCTION IN OLDER PEOPLE

Abstract Muscle loss might occur in aging, target organ failure, metabolic and endocrine disorders, etc. The aim of this study was to identify the high-risk group of low grip strength, a key component of sarcopenia. 100 subjects aged 65 or older who received Comprehensive Geriatric Assessment (CGA) and grip strength measurement were enrolled at EDA Hospital, Taiwan, form January 2022 to February, 2023 (IRB: EMRP-110-108). Exclusion criteria: unclear consciousness or unable to cooperate 、advanced disease. CGA and grip strength measurement were performed by well-trained nurses and geriatrician. Depressive mood was defined as Geriatric Depression Scale-5 ≧2 or with diagnosed depression. Cognitive impairment was defined as Short Portable Mental State Questionnaire (SPMSQ) &amp;lt; 8 (SPMSQ &amp;lt; 6 in those without education) or with diagnosed dementia. Multiple linear regression was constructed to assess the independent associated factors on increased average grip strength of bilateral hands. Univariate analysis showed male, weight, ADL significantly associated with greater grip strength. Multiple linear regression revealed CKD(ß= -7.70, 95%CI -13.35~-2.05, p=0.011), COPD(ß= -9.15, 95%CI -17.15~-1.17, p=0.027 ), cognitive impairment(ß= -7.67, 95%CI -12.66~-2.65, p=0.005) and depressive mood(ß= -8.39, 95%CI -13.46~-3.32, p=0.003) have detrimental effect on grip strength even after adjustment of age, sex, BMI, socioeconomics, chronic comorbidities, and other geriatric syndromes. Our results resemble another sarcopenia study in which poor muscle function, but not reduced lean muscle mass, was associated with late-life cognitive impairment. Therefore, early screening, education, and intervention of sarcopenia should be applied on high-risk population such as those with CKD, COPD, cognitive impairment, and depressive mood.

EFFECTS OF HIGH-INTENSITY AQUATIC EXERCISE ON INFLAMMATION AND COGNITION IN OLDER ADULTS WITH MCI

Abstract Exercise shows immune benefits in older adults and can reduce the risk of late-life cognitive impairment and dementia. This study sought to explore the effects of high-intensity aquatic-based exercise on older adults with mild cognitive impairment (MCI), specifically by examining changes in inflammatory plasma protein concentrations and cognitive performance. A secondary data analysis was conducted on 20 healthy volunteers (mean age 68.2 ±7.75 years) who participated in 6 months of supervised aquatic exercise training. Participants completed a battery of neuropsychological assessments and whole blood draws at pre- and post-intervention. Plasma protein concentration levels were attained using the Olink Target96 Inflammation panel [Uppsala, Sweden]. Mixed effects models assessed the effects of protein concentration change scores on selected cognitive outcomes, while controlling for age. Results indicated that following the exercise intervention, significant changes in two inflammatory-related proteins (Extracellular newly identified receptor for advanced glycation end-products binding protein [EN-RAGE]; Interleukin-20 receptor subunit alpha [IL-20RA]) were associated with improved verbal memory and processing speed endpoints. Specifically, decreased EN-RAGE concentrations resulted in significantly improved delayed verbal memory scores (parameter estimate= -0.893, p= .023), while increased IL-20RA concentrations led to better task completion (parameter estimate= 2.145, p= .030). These findings demonstrate the cognitive benefits of aquatic-based exercise for older adults and those with MCI, and suggest these effects are mediated by alterations in pro- and anti-inflammatory protein markers such as EN-RAGE and IL-20RA. Larger studies are warranted to replicate these findings, and to further explore the role of activity-induced inflammatory changes on late-life brain health.

Physically demanding work and cognitive impairment in late life

AbstractBackgroundCognitive decline is increasing in prevalence worldwide and poses a heavy burden on society. Sociodemographic factors and health behaviors associated with cognitive decline have been described. While physical exercise has been reported as a protective factor, less education acts as a risk factor. Conversely, work activities associated with lower educational levels are frequently more physically demanding. Few studies have analyzed the impact of work activities on cognition.MethodWe used data from the Brazilian Longitudinal Study of Aging, with a sample of 8,336 complete cases. Linear regression was performed to assess the impact of physical demand at work on cognitive performance, as measured by a global cognitive score composed of temporal orientation, verbal fluency, and memory tests. Work activities were classified by the question “How would you describe physical demand of the job you had most of your life?”, with the following possible answers: “mostly sitting”, “mostly standing or walking”, “some physical effort” and “intense physical effort”. Age, sex, marital status, educational level, household income per capita, number of comorbidities, smoking and alcohol consumption, and level of physical activity were used as covariates.ResultWhen compared to a “mostly sitting” type of work (e.g., office job), a “mostly standing or walking” (e.g., security worker) job did not show any difference in cognitive performance (β = ‐0.03, p = 0.089). On the other hand, a “some physical effort” job (carrying weights or using tools, such as nurse or carpenter) and an “intense physical effort” job (carrying heavy weights, such as miner or construction worker) showed an increasingly worse cognitive performance (respectively, β = ‐0.09, p = 0.000 and β = ‐0.11, p = 0.000).ConclusionAlthough sedentarism has been shown to be associated with a worse cognitive performance and increased dementia risk, physically demanding jobs do not appear to be beneficial. Meanwhile, work stress associated with these activities might exert a negative effect on cognition independent of educational level and physical exercise unrelated to work. Some data suggest mentally demanding jobs, on the contrary, can be beneficial. With development of new technologies, moving from physical work into mental work can potentially reduce dementia risk.

P140: Midlife diet and risk of dementia/mild cognitive impairment

The Japan Public Health Center-based prospective (JPHC) Study is a large population-based cohort. Midlife dietary intake was assessed on two occasions: in the years 1995 and 2000 (aged 45-64 in 1995). In 2014-2015, approximately 1300 participants from Saku district in Nagano prefecture completed a mental health screening including later life depression and cognitive decline (i.e., mild cognitive impairment (MCI) and dementia). We used logistic regression analyses to calculate odds ratios (ORs) for MCI and dementia. Based on this survey, we found the following characteristics of midlife diet, which may be useful information to prevent cognitive decline/dementia.1.High-density lipoprotein cholesterol (HDL-C) and later cognitive decline (Svensson et al. Transl Psychiatry, 2019): Midlife high-density lipoprotein cholesterol (HDL-C) is a measure which could help identify individuals at reduced risk of developing age-related cognitive decline. Compared to the lowest HDL-C quartile, the highest HDL-C quartile was significantly inversely associated with MCI. High HDL-C (quartiles 2-4) was inversely associated with dementia compared to low HDL-C (quartile 1).2.Dietary fish and n-3 polyunsaturated fatty acid (PUFA) and later cognitive decline (Nozaki et al. J Alzheimers Dis, 2021): Higher intake of fish, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) in midlife significantly reduced risks of dementia.3.Intake of soy and the isoflavone and later cognitive decline (Svensson et al. J Alzheimers Dis, 2021): Compared to the lowest dietary quartile of energy-adjusted isoflavone genistein intake, the highest quartile was significantly associated with late-life cognitive impairment.4.Cancer/diabetes and later cognitive decline (Sadahiro et al. Psychiatry Clin Neurosci, 2019): Comorbid cancer and diabetes from midlife may increase the risk of MCI or dementia in later life. In addition to the increased dementia risk associated with diabetes on the basis of insulin resistance, cancer and cancer therapies may also interfere with cognitive function via insulin resistance.

6 The Role of CPAP Treatment on Associations Between Obstructive Sleep Apnea and Cognition Among Black and White Older Adults

Objective:Obstructive sleep apnea (OSA) may be a modifiable risk factor for late-life cognitive impairment. We previously demonstrated that non-Hispanic Black older adults are less likely to be diagnosed with OSA despite having equal or greater health risk for OSA compared to non-Hispanic White older adults, and this disparity in diagnosis was strongest among individuals with lower education. Here, we aimed to determine 1) whether there are racial differences in continuous positive airway pressure (CPAP) treatment, 2) how CPAP treatment may influence OSA-cognition associations, and 3) whether CPAP differentially influences OSA-cognition associations across racial groups.Participants and Methods:Cross-sectional data were obtained from 424 socioeconomically diverse community-dwelling adults ages 55-83 (63.4±3.2 years, 41.7% male, 53.5% Black) from the Michigan Cognitive Aging Project. Physician-diagnosed OSA and current CPAP use were self-reported. Global cognition was operationalized as a composite of five factor scores derived from a comprehensive neuropsychological battery. Racial group differences were investigated with chi-square and Fisher’s exact tests with statistical significance set at the .05 level. Associations between OSA and cognition (adjusted for age, gender, race, and years of education) were investigated with linear regressions. Subsequent models isolated effects of uncontrolled OSA by excluding individuals using CPAP. Racial differences in OSA-cognition associations were investigated with race-stratified models.Results:Fewer Black participants (9.2%) reported diagnosed OSA compared to White participants (12.3%; x2 (1, N=424) =5.314, p=.021, cp=.112). In the whole sample, 47.3% of participants with diagnosed OSA reported CPAP use, and this proportion did not differ across race (x2 [1, N=86] =.048, p=.826). In the whole sample, OSA diagnosis was only associated with cognition when CPAP users were excluded (excluding CPAP users: ß=-.085, SE=.037, p=.024; including CPAP users: ß=-.067, SE=.036, p=.062). In race-stratified models, diagnosed OSA was only associated with cognition among Black participants, and this association was stronger when CPAP users were excluded (excluding CPAP users: ß=-.142, SE=.060, p=.018; including CPAP users: ß=-.126, SE=.058, p=.030). Diagnosed OSA was not associated with cognition among White participants, irrespective of whether CPAP users were included (excluding CPAP users: ß=-.084,SE=.068, p=.215; including CPAP users: ß=-.056, SE=.064, p=.378).Conclusions:Our findings support CPAP treatment as a potential intervention to mitigate late-life cognitive impairment among those with OSA. Despite being less likely to receive a diagnosis of OSA, Black older adults were equally likely to engage in CPAP treatment as White older adults when diagnosed. The detrimental impact of OSA on cognition may be more salient among Black older adults, which may reflect racial disparities in cardiovascular risk and/or resources that promote cognitive reserve. However, CPAP appears to be an effective treatment to reduce OSA-related cognitive impairment for Black older adults, highlighting the critical importance of diagnosis and treatment in this group. Intervention efforts that abate racial inequalities in access to quality healthcare in order to facilitate acquisition of a formal OSA diagnosis and CPAP treatment may help to reduce preventable cognitive health disparities among older adults.

3 Does External Locus of Control Moderate the Intergenerational Transmission of Dementia Risk Among Non-Latinx Black and Non-Latinx White Middle-Aged Adults?

Objective:People whose parents had dementia or memory impairment are at higher risk for later-life cognitive impairment themselves. One goal of our research is to identify factors that either increase the risk of or protect against family history of dementia over the life course. External locus of control has been associated with lower cognitive function in middle-aged and older adults. Previous findings have shown that adults racialized as Black have relatively high levels of external locus of control due to inequity and racism. We hypothesized that lower parental memory would be associated with lower offspring memory among Non-Latinx Black and Non-Latinx White (hereafter Black and White, respectively) adults; and associations would be stronger among participants with higher levels of external locus of control.Participants and Methods:Participants comprised 594 adults racialized as Black or White (60.3% Black; 62% women; aged 56.1 ± 10.4; 15.3 ± 2.7 years of education) from the Offspring Study who are the adult children of participants in the Washington Heights Inwood Columbia Aging Project (WHICAP). Parental memory was residualized for age (74.3 ± 6.0) and education (13.7 ± 3.1). Self-reported external locus of control was assessed using 8 items from the the perceived control questionnaire. Memory was assessed with the Selective Reminding Test, and a composite of total and delayed recall scores were computed. Linear regression quantified the interaction between parental memory and external locus of control on memory in models stratified by race, and adjusted for age, sex/gender, and number of chronic health diseases.Results:Among Black participants (n=358), there were no main effects of parental memory or locus of control on offspring memory. However, lower parental memory was associated with lower offspring memory among Black participants with high levels of external locus of control (standardized estimate=0.36, p=0.02, 95%CI [0.05, 0.67]). Associations were attenuated and non-significant at lower levels of control. Among White participants (n=236), there was a main effect of parental memory on offspring memory, and this association did not vary by levels of external locus of control.Conclusions:Poor parental memory, which reflects risk for later-life cognitive impairment and dementia, was associated with lower memory performance among White middle-aged participants. Among Black participants, this association was observed among those with high levels of external locus of control only. Economic and social constraints shape levels of external locus of control and are disproportionately experienced by Black adults. In the face of greater external locus of control, a cascade of psychological and biological stress-related processes may be triggered and make Black adults’ memory function more vulnerable to the detrimental impact of parent-related dementia risk. Longitudinal analyses are needed to clarify temporal associations. Nonetheless, these findings suggest that reducing social and economic inequities disproportionately experienced by Black adults may dampen the effect of intergenerational transmission of dementia risk on cognition.

Vascular Burden Moderates the Relationship Between ADHD and Cognition in Older Adults

ObjectivesRecent evidence suggests attention-deficit/hyperactivity disorder (ADHD) is a risk factor for cognitive impairment in later life. Here, we investigated cerebrovascular burden, quantified using white matter hyperintensity (WMH) volumes, as a potential mediator of this relationship. DesignThis was a cross-sectional observational study. SettingParticipants were recruited from a cognitive neurology clinic where they had been referred for cognitive assessment, or from the community. ParticipantsThirty-nine older adults with clinical ADHD and 50 age- and gender-matched older adults without ADHD. MeasurementsA semiautomated structural MRI pipeline was used to quantify periventricular (pWMH) and deep WMH (dWMH) volumes. Cognition was measured using standardized tests of memory, processing speed, visuo-construction, language, and executive functioning. Mediation models, adjusted for sex, were built to test the hypothesis that ADHD status exerts a deleterious impact on cognitive performance via WMH burden. ResultsResults did not support a mediated effect of ADHD on cognition. Post hoc inspection of the data rather suggested a moderated effect, which was investigated as an a posteriori hypothesis. These results revealed a significant moderating effect of WMH on the relationship between ADHD memory, speed, and executive functioning, wherein ADHD was negatively associated with cognition at high and medium levels of WMH, but not when WMH volumes were low. ConclusionsADHD increases older adults’ susceptibility to the deleterious cognitive effects of WMH in the brain. Older adults with ADHD may be at risk for cognitive impairment if they have deep WMH volumes above 61 mm3 and periventricular WMH above 260 mm3.

Associations between lipid profiles and late-life cognitive impairment among oldest-old and centenarian adults.

Dyslipidemia and cognitive impairment are common among old adults and the occurrence of them rises exponentially with increasing age. Evidences of the relationships between serum lipids and cognitive impairment are inconsistent or equivocal among older adults. This study aimed to investigate the associations between lipid profiles and late-life cognitive impairment among oldest-old and centenarian adults. In this cross-sectional study, serum lipids were biochemically measured among 606 oldest-old adults and 653 centenarians, and cognitive function was evaluated using mini-mental state examination (MMSE). Multivariate linear and logistic regression analyses were performed to explore the associations between serum lipids and cognitive impairment. Results showed participants with cognitive impairment had lower total cholesterol (TC) levels compared with those without cognitive impairment (p<0.05). TC levels were positively associated with MMSE (p<0.05). Furthermore, a negative association was observed between TC levels and cognitive impairment (p for trend=0.002). This negative association remained statistically significant after adjusting for confounders (p for trend=0.028). These results suggested that older adults with higher TC levels were likely to have better cognitive function. Taking immoderate cholesterol-lowering drugs among older adults is questionable and requires investigation, and cognitive performance of old adults with lower TC levels deserves more attention.