Slower Rate Of Cognitive Decline Research Articles

Leisure activity engagement across adulthood predicts cognitive change after five years: Do gender and age matter?

To examine the association between leisure activity (LA) frequency and cognitive trajectories over 5 years across adulthood, and whether gender and age moderate these associations. A total of 234 cognitively healthy adults (21-80 years) completed a LA questionnaire at baseline and neuropsychological measures at baseline and after 5 years. Latent change score analysis was applied to generate latent variables estimating changes in different cognitive domains. For a secondary analysis, LA components' scores were calculated, reflecting cognitive-intellectual, social, and physical activities. Regression analysis examined the association between baseline LA and cognitive change, and potential moderation of gender and age. In addition, we tested the influence of cortical gray matter thickness on the results. We found that higher LA engagement was associated with slower cognitive decline for reasoning, speed, and memory, as well as better vocabulary across two time points. Regarding LA components, higher Social-LA and Intellectual-LA predicted slower rates of cognitive decline across different domains, while Physical-LA was not associated with cognitive change. Gender, but not age, moderated some of the associations observed. Our results remained the same after controlling for cortical gray matter thickness. We demonstrated a protective effect of LA engagement on cognitive trajectories over 5 years, independent from demographics and a measure of brain health. The effects were in part moderated by gender, but not age. Results should be replicated in larger and more diverse samples. Our findings support cognitive reserve hypothesis and have implications for future reserve-enhancing interventions.

Intellectual enrichment and genetic modifiers of cognition and brain volume in Huntington's disease.

An important step towards the development of treatments for cognitive impairment in ageing and neurodegenerative diseases is to identify genetic and environmental modifiers of cognitive function and understand the mechanism by which they exert an effect. In Huntington's disease, the most common autosomal dominant dementia, a small number of studies have identified intellectual enrichment, i.e. a cognitively stimulating lifestyle and genetic polymorphisms as potential modifiers of cognitive function. The aim of our study was to further investigate the relationship and interaction between genetic factors and intellectual enrichment on cognitive function and brain atrophy in Huntington's disease. For this purpose, we analysed data from Track-HD, a multi-centre longitudinal study in Huntington's disease gene carriers and focused on the role of intellectual enrichment (estimated at baseline) and the genes FAN1, MSH3, BDNF, COMT and MAPT in predicting cognitive decline and brain atrophy. We found that carrying the 3a allele in the MSH3 gene had a positive effect on global cognitive function and brain atrophy in multiple cortical regions, such that 3a allele carriers had a slower rate of cognitive decline and atrophy compared with non-carriers, in agreement with its role in somatic instability. No other genetic predictor had a significant effect on cognitive function and the effect of MSH3 was independent of intellectual enrichment. Intellectual enrichment also had a positive effect on cognitive function; participants with higher intellectual enrichment, i.e. those who were better educated, had higher verbal intelligence and performed an occupation that was intellectually engaging, had better cognitive function overall, in agreement with previous studies in Huntington's disease and other dementias. We also found that intellectual enrichment interacted with the BDNF gene, such that the positive effect of intellectual enrichment was greater in Met66 allele carriers than non-carriers. A similar relationship was also identified for changes in whole brain and caudate volume; the positive effect of intellectual enrichment was greater for Met66 allele carriers, rather than for non-carriers. In summary, our study provides additional evidence for the beneficial role of intellectual enrichment and carrying the 3a allele in MSH3 in cognitive function in Huntington's disease and their effect on brain structure.

Association of Greenspace Exposure at Midlife with Cognitive Decline Later in Life in a Study of US Women

Background and aim: Greenspace may slow cognitive decline by increasing opportunities for physical activity and social connection or reducing stress or air pollution. However, studies on the association between greenspace and cognitive decline are sparse. We investigated the prospective association between greenspace at midlife and cognitive decline later in life. Methods: Using data from the US-based Nurses’ Health Study (mean age=61y), we assessed residential greenspace in a 270m buffer as the cumulative average from 1986 to 1994 using Landsat Normalized Difference Vegetation Index data. We examined 16,352 women who were enrolled in a substudy starting in 1995-2001 (74y) through 2008. Participants underwent up to four repeated measures of five cognitive tests. A global composite score was calculated as the average of all z-scores for each task to evaluate overall cognitive functioning. We evaluated the association between greenspace and subsequent cognitive decline using linear mixed models adjusted for age, education, neighborhood socioeconomic status, and depression. Results: In fully adjusted models, those living in the highest quintile of greenspace had an annual slope of decline that was slower by 0.01 units of the global composite score (95%CI 0.00001, 0.012) compared to those in the lowest quintile. To help interpret this estimate, we find that one year of age is related to a -0.01 unit mean annual difference for global cognition; thus, more greenspace appeared equivalent to slowing cognitive aging by one year. We found similar associations for the Telephone Interview for Cognitive Status (TICS); participants living in the highest greenspace quintile had an annual rate of decline that was slower by 0.04 units in the TICS score (95%CI 0.01, 0.07) compared to those in the lowest quintile. Conclusions: Higher greenspace exposure in early adulthood is associated with a slower rate of cognitive decline later in life in this cohort of US women.

Lifestyle and Cognitive Decline in Community-Dwelling Stroke Survivors.

Patients with stroke are at a higher risk of cognitive impairment and Alzheimer's disease dementia. To quantify the role of lifestyle pre-stroke, post-stroke, and changes in lifestyle before and after stroke with cognitive decline in community-dwelling stroke survivors. Utilizing data from the Chicago Health and Aging Project, a population-based cohort study, we studied 1,078 individuals with stroke (662 incident and 416 prevalent) who underwent cognitive testing during the study period. A healthy lifestyle score was defined by scoring four behaviors: non-smoking, exercising, being cognitively active, and having a high-quality diet. The global cognitive score was derived from a comprehensive battery of 4 standardized tests. The mean age at incident stroke was 78.2 years, and 60.1% were women. A healthy lifestyle pre-incident stroke was associated with a slower rate of cognitive decline after stroke. Participants with 3-4 healthy lifestyle factors pre-incident stroke had a slower cognitive decline after stroke by 0.046 units/year (95% CI 0.010, 0.083), or 47.7% slower, than participants with 0-1 healthy lifestyle factor. Lifestyle score post-prevalent stroke was not associated with cognitive decline. Changes in lifestyle behaviors from pre- to post-incident stroke were related to cognitive decline after stroke. Individuals who deteriorated their lifestyle quality after stroke had a faster cognitive decline by 0.051 units/year (β -0.051, 95% CI -0.090, -0.012) than participants with no change in lifestyle score. A healthy lifestyle pre-stroke was associated with a slower rate of cognitive decline in stroke survivors, highlighting the importance of primary prevention. After the stroke, changes in lifestyle behaviors may influence the cognitive abilities of older adults as they age.

Adherence to MIND Diet, Genetic Susceptibility, and Incident Dementia in Three US Cohorts.

Adherence to Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) may lower the risk of dementia by impacting immunity and cholesterol, which are pathways also implicated by genome-wide association studies of Alzheimer’s Dementia (AD). We examined whether adherence to the MIND diet could modify the association of genetic risk for AD with incident dementia. We used three ongoing US cohorts: Chicago Health and Aging Project (CHAP, n = 2449), Rush Memory and Aging Project (MAP, n = 725), and Women’s Health Initiative Memory Study (WHIMS, n = 5308). Diagnosis of dementia was based on clinical neurological examination and standardized criteria. Repeated measures of global cognitive function were available in MAP and CHAP. Self-reported adherence to MIND was estimated using food-frequency questionnaires. Global and pathway-specific genetic scores (GS) for AD were derived. Cox proportional hazard, logistic regression, and mixed models were used to examine associations of MIND, GS, and GS-MIND interactions with incident dementia and cognitive decline. Higher adherence to MIND and lower GS were associated with a lower risk of dementia in MAP and WHIMS and a slower rate of cognitive decline in MAP (p < 0.05). MIND or GS were not associated with incident dementia or cognitive decline in CHAP. No gene–diet interaction was replicated across cohorts. Genetic risk and MIND adherence are independently associated with dementia among older US men and women.

Bulk and Single-Nucleus Transcriptomics Highlight Intra-Telencephalic and Somatostatin Neurons in Alzheimer's Disease.

Cortical neuron loss is a pathological hallmark of late-onset Alzheimer’s disease (AD). However, it remains unclear which neuronal subtypes beyond broad excitatory and inhibitory classes are most vulnerable. Here, we analyzed cell subtype proportion differences in AD compared to non-AD controls using 1037 post-mortem brain samples from six neocortical regions. We identified the strongest associations of AD with fewer somatostatin (SST) inhibitory neurons (β = −0.48, pbonf = 8.98 × 10–9) and intra-telencephalic (IT) excitatory neurons (β = -0.45, pbonf = 4.32 × 10–7). Replication in three AD case-control single-nucleus RNAseq datasets most strongly supported the bulk tissue association of fewer SST neurons in AD. In depth analyses of cell type proportions with specific AD-related neuropathological and cognitive phenotypes revealed fewer SST neurons with greater brain-wide post-mortem tau and beta amyloid, as well as a faster rate of antemortem cognitive decline. In contrast, greater IT neuron proportions were associated with a slower rate of cognitive decline as well as greater residual cognition–a measure of cognitive resilience–but not canonical AD neuropathology. Our findings implicate somatostatin inhibitory and intra-telencephalic excitatory neuron subclasses in the pathogenesis of AD and in cognitive resilience to AD pathology, respectively.

Higher Serum DHA and Slower Cognitive Decline in Patients with Alzheimer's Disease: Two-Year Follow-Up.

Omega-3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been associated with slower rates of cognitive decline. We investigated the association between omega-3 PUFAs and cognitive function in patients with Alzheimer’s disease (AD) receiving acetylcholinesterase inhibitors (AChEIs). This was a prospective cohort study using registered data. Patients with AD receiving AChEIs were recruited from 1 May 2016 to 30 April 2019 and were followed up for two years. Their daily diet record and blood concentration of omega-3 PUFAs were analyzed. Multiple linear and binary logistic regression was used to determine the factors associated with cognitive decline (continuous and dichotomized cognitive change). In the research, 129 patients with AD were identified with a mean age of 76.5 ± 6.6. Patients with AD with lower baseline omega-3 PUFAs levels were associated with a higher risk of cognitive decline than those with higher levels (odds ratio [OR] = 1.067, 95% confidence interval [CI]: 1.012, 1.125; p = 0.016) after adjustment. Patients with AD with a lower baseline DHA (OR = 1.131, 95% CI: 1.020, 1.254; p = 0.020), but not EPA, were associated with a higher risk of cognitive decline. We found that higher Mini-Nutritional Assessment scores (beta = −0.383, 95% CI = −0.182–−0.048, p = 0.001) and total fat (beta = −0.248, 95% CI = −0.067–−0.003, p = 0.031) were independently associated with slow cognitive decline in patients with AD receiving AChEIs. The baseline blood levels of omega-3 PUFAs were associated with cognitive decline in patients with AD receiving AChEIs. Future randomized controlled trials are needed to clarify whether this association is causal.

Perceptions of Childhood Neighborhood Social Cohesion and Cognitive Function in Middle and Late Adulthood.

Framed within the life course perspective and the neighborhood stress model, this study investigated the association between perceptions of childhood neighborhood social cohesion and cognitive function among middle-aged and older Chinese adults. We also examined whether gender, childhood hukou status, the Chinese national administrative household registration system, and birth cohort moderated the association. This study used 3 waves of nationally representative data from the China Health and Retirement Longitudinal Study (2011-2015; N = 11,469). Cognitive function was measured with the Telephone Interview for Cognition Status instrument. Two-level multilevel modeling was employed to address the research questions. A higher overall level of childhood neighborhood social cohesion was associated with a higher baseline level of cognitive function (b = 0.26, p < .001) and a slower rate of cognitive decline (b = 0.10, p = .010). Birth cohort membership moderated the linkage between childhood neighborhood social cohesion and the level of cognitive function (b = 0.35, p < .001) and cognitive decline (b = 0.19, p = .014). Gender and childhood hukou status did not moderate these associations. These findings underscored the long-term ramifications of childhood conditions for later-life cognitive function. Social cohesion at the neighborhood level during childhood may be a factor that promotes healthy cognitive aging.

Cognitive reserve over life course and 7-year trajectories of cognitive decline: results from China health and retirement longitudinal study

BackgroundCognitive reserve (CR) could partly explain the individual heterogeneity in cognitive decline. No study measured CR from a life course perspective and investigated the association between CR and trajectories of cognitive decline in older Chinese adults.MethodsData of 6795 Chinese adults aged 60+ from China Health and Retirement Longitudinal Study were used. Global cognition score (0–32) was assessed in all four waves. A life-course CR score was constructed using markers of childhood circumstance, education, highest occupational class, and leisure activities in later life. Latent growth curve modelling (LGCM) was applied to assess the association between CR and trajectories of cognitive decline.ResultsFor the life-course CR, factor loadings of markers in adulthood and later life were larger than that of markers in childhood. The life-course CR score (ranged between − 2.727 and 6.537, SD: 1.74) was higher in urban Chinese adults (0.75, SD: 1.90) than in rural Chinese adults (− 0.50, SD: 1.43). The unconditional LGCM results showed that urban older Chinese adults had better global cognition at baseline (intercept: 15.010, 95% CI: 14.783, 15.237) and a slower rate of cognitive decline per year (linear slope: -0.394, 95% CI: − 0.508, − 0.281) than their rural counterparts (intercept: 12.144, 95% CI: 11.960, 12.329; linear slope: -0.498, 95% CI: − 0.588, − 0.408). After controlling for all covariates, one-unit higher CR score was associated with 1.615 (95% CI: 1.521, 1.709) and 1.768 (95% CI: 1.659, 1.876) unit higher global cognition at baseline for urban and rural older Chinese adults, respectively. The slower rate of cognitive decline associated with higher CR was more evident in rural residents (slope: 0.083, 95% CI: 0.057, 0.108) than in their urban counterparts (0.054, 95% CI: 0.031, 0.077).ConclusionsCR was associated with better baseline cognition and slower cognitive decline in Chinese older adults. Although rural residents were disadvantaged in both CR and cognition, the protective effect of CR against cognitive decline was stronger for them than in those who live in urban area.

Air quality improvement and cognitive decline in community-dwelling older women in the United States: A longitudinal cohort study.

Late-life exposure to ambient air pollution is a modifiable risk factor for dementia, but epidemiological studies have shown inconsistent evidence for cognitive decline. Air quality (AQ) improvement has been associated with improved cardiopulmonary health and decreased mortality, but to the best of our knowledge, no studies have examined the association with cognitive function. We examined whether AQ improvement was associated with slower rate of cognitive decline in older women aged 74 to 92 years. We studied a cohort of 2,232 women residing in the 48 contiguous US states that were recruited from more than 40 study sites located in 24 states and Washington, DC from the Women's Health Initiative (WHI) Memory Study (WHIMS)-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO) study. They were predominantly non-Hispanic White women and were dementia free at baseline in 2008 to 2012. Measures of annual (2008 to 2018) cognitive function included the modified Telephone Interview for Cognitive Status (TICSm) and the telephone-based California Verbal Learning Test (CVLT). We used regionalized universal kriging models to estimate annual concentrations (1996 to 2012) of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) at residential locations. Estimates were aggregated to the 3-year average immediately preceding (recent exposure) and 10 years prior to (remote exposure) WHIMS-ECHO enrollment. Individual-level improved AQ was calculated as the reduction from remote to recent exposures. Linear mixed effect models were used to examine the associations between improved AQ and the rates of cognitive declines in TICSm and CVLT trajectories, adjusting for sociodemographic (age; geographic region; race/ethnicity; education; income; and employment), lifestyle (physical activity; smoking; and alcohol), and clinical characteristics (prior hormone use; hormone therapy assignment; depression; cardiovascular disease (CVD); hypercholesterolemia; hypertension; diabetes; and body mass index [BMI]). For both PM2.5 and NO2, AQ improved significantly over the 10 years before WHIMS-ECHO enrollment. During a median of 6.2 (interquartile range [IQR] = 5.0) years of follow-up, declines in both general cognitive status (β = -0.42/year, 95% CI: -0.44, -0.40) and episodic memory (β = -0.59/year, 95% CI: -0.64, -0.54) were observed. Greater AQ improvement was associated with slower decline in TICSm (βPM2.5improvement = 0.026 per year for improved PM2.5 by each IQR = 1.79 μg/m3 reduction, 95% CI: 0.001, 0.05; βNO2improvement = 0.034 per year for improved NO2 by each IQR = 3.92 parts per billion [ppb] reduction, 95% CI: 0.01, 0.06) and CVLT (βPM2.5 improvement = 0.070 per year for improved PM2.5 by each IQR = 1.79 μg/m3 reduction, 95% CI: 0.02, 0.12; βNO2improvement = 0.060 per year for improved NO2 by each IQR = 3.97 ppb reduction, 95% CI: 0.005, 0.12) after adjusting for covariates. The respective associations with TICSm and CVLT were equivalent to the slower decline rate found with 0.9 to 1.2 and1.4 to 1.6 years of younger age and did not significantly differ by age, region, education, Apolipoprotein E (ApoE) e4 genotypes, or cardiovascular risk factors. The main limitations of this study include measurement error in exposure estimates, potential unmeasured confounding, and limited generalizability. In this study, we found that greater improvement in long-term AQ in late life was associated with slower cognitive declines in older women. This novel observation strengthens the epidemiologic evidence of an association between air pollution and cognitive aging.

Longitudinal changes in behaviour, mood and functional capacity in the primary progressive aphasia variants.

Primary progressive aphasia (PPA) is a neurodegenerative clinical syndrome characterised by a progressive decline in speech and language functions. Deficits in behaviour, mood and functional capacity are reported in PPA but are less well understood. This study examined the PPA variants' profiles on these domains at initial presentation and over time and evaluated their relations to overall cognitive ability. Behaviour, mood and functional capacity were measured annually (over ~6years) in 145 individuals diagnosed with PPA (41 logopenic [lv-PPA], 44 non-fluent [nfv-PPA] and 60 semantic variants [sv-PPA]) using the Cambridge Behavioural Inventory-Revised (CBI-R) carer questionnaire. Overall cognition was assessed annually with the Addenbrooke's Cognitive Examination-III. Distinct profiles were observed across PPA syndromes. Notably, sv-PPA carers reported greater behavioural, eating and motivational disturbances than the other PPA variants throughout the disease course. Reported memory problems were also greater in sv-PPA and lv-PPA than in nfv-PPA across all time points. These disturbances occurred in the context of the sv-PPA group demonstrating a slower rate of cognitive decline than the lv-PPA group and a parallel rate to that found in the nfv-PPA group. Associations between overall cognition and the CBI-R domains were trivial at baseline assessment; however, distinct profiles emerged when mapping each syndrome's overall cognitive decline with their behavioural, mood and functional trajectories. Our findings demonstrate that the evolving behaviour, mood and functional capacity profiles of the PPA variants are distinct and extend beyond the primary disorder of language. These findings have important implications for clinical management and caregiver education in PPA.

The Relationship Between Cardiovascular Health and Rate of Cognitive Decline in Young-Old and Old-Old Adults: A Population-Based Study.

Background:Modifiable vascular risk factors have been associated with late-life cognitive impairment. The Life Simple 7 (LS7) score comprises seven cardiovascular health metrics: smoking, diet, physical activity, body mass index, plasma glucose, total serum cholesterol, and blood pressure.Objective:To investigate the association between individual and composite LS7 metrics and rate of cognitive decline, and potential differences in these associations between young-old and old-old individuals.Methods:This cohort study included 1,950 participants aged≥60 years (M = 70.7 years) from the Swedish National Study on Aging and Care-Kungsholmen (SNAC-K), who underwent repeated neuropsychological testing (episodic and semantic memory, verbal fluency, processing speed, global cognition) across 12 years. The LS7 score was assessed at baseline and categorized as poor, intermediate, or optimal. Level and change in cognitive performance as a function of LS7 categories were estimated using linear mixed-effects models.Results:Having an optimal LS7 total score was associated with better performance (expressed in standard deviation units) at baseline for perceptual speed (β= 0.21, 95%CI 0.12–0.29), verbal fluency (β= 0.08, 0.00–0.16), and global cognition (β= 0.06, 0.00–0.12) compared to the poor group. Age-stratified analyses revealed associations for cognitive level and change only in the young-old (< 78 years) group. For the specific metrics, diverging patterns were observed for young-old and old-old individuals.Conclusion:Meeting the LS7 criteria for ideal cardiovascular health in younger old age is associated with slower rate of cognitive decline. However, the LS7 criteria may have a different meaning for cognitive function in very old adults.

Trajectory classes of social activity and their effects on longitudinal changes in cognitive function among older adults

Objectives: This study aimed to identify the social activity trajectory by class and the effects on the cognitive function trajectory among older adults. Methods: Data from six waves of the 2006–2016 Korean Longitudinal Study of Aging were analyzed. This study included 3,002 participants aged ≥65 years. Latent class growth modeling was used to classify the respondents based on their engagement in social activity over 10 years. Latent growth modeling was used to examine the effect of their social activity trajectory by class to predict participants’ cognitive function trajectory. Results: We identified four social activity trajectory classes: high-stable (7.8%), moderate-stable (50.3%), high-decreasing (2.9%), and low-decreasing (39.0%). Older adults with an age of 75 years or older, a low education level, instrumental activities of daily living limitations, and depressive symptoms were more likely to be in the low-decreasing social activity trajectory class. The respondents in the high-stable (B = 0.680, p < 0.001) and moderate-stable (B = 0.362, p < 0.001) classes showed a slower rate of cognitive decline compared with those in the low-decreasing class. Discussion: Community-based strategies need to be developed to encourage older adults to maintain their social activity engagement and ultimately prevent cognitive decline.

APOE E2/E2 Is Associated with Slower Rate of Cognitive Decline with Age.

The E4 allele of the APOE gene is known to be associated with cognitive impairment. However, a limited number of studies have examined the association between the E2 allele and longitudinal changes of cognitive function. To determine whether rates of cognitive change differ in carriers of the APOE E2 allele compared to other genotypes. We conducted a secondary analysis of data from two ongoing longitudinal cohort studies, the Long Life Family Study (LLFS) and New England Centenarian Study (NECS). We included participants who had APOE genotyping data, data from longitudinal administrations of the Telephone Interview for Cognitive Status (TICS), and age, sex, and education available. We assessed whether cognitive change as measured by rate of decline in TICS score differed among people with different APOE genotypes. We used a hierarchical mixed effect model with APOE genotypes, their interactions with age, and potential confounders. After adjusting for sex and education, in carriers of the common E3/E3 genotype, TICS score decreased by 0.15 points per year of age. In those with the E2/E2 genotype, TICS score decreased by 0.05 points per year of age, a significantly slower rate of decline (p = 0.017). We observed no protective effect of the E2/E3 genotype on cognitive decline. These results suggest a protective effect of the E2/E2 genotype on a measure of global cognitive function.

Psychological Well-Being and Cognitive Function among Older Adults in China: A Population-Based Longitudinal Study.

ObjectivesThis study aims to examine the relationship between psychological well-being (PWB) and cognitive function in older adults in China. Methods: Data are from the Chinese Longitudinal Healthy Longevity Survey. Analyses were restricted to 9,487 older persons (age ≥ 60) without cognitive impairment at baseline. Respondents were followed over a 12-year period. Cognitive function was assessed using the Chinese version of the Mini-Mental State Examination (C-MMSE). PWB was assessed using a composite index capturing optimism, conscientiousness, neuroticism, loneliness, personal control, self-esteem, and happiness. Results: Multilevel mixed effects generalized linear models showed that respondents with greater PWB had a slower rate of cognitive decline over time, adjusting for sociodemographic and health characteristics. In addition, multilevel multinomial logistic regression models showed that greater PWB was associated with lower odds of developing cognitive impairment. Conclusions: Findings suggest that fostering PWB may prevent or delay adverse cognitive changes.

Legacy of a 10-Year Multidomain Lifestyle Intervention on the Cognitive Trajectories of Individuals with Overweight/Obesity and Type 2 Diabetes Mellitus

Introduction: Weight loss and increased physical activity interventions are commonly recommended for individuals with type 2 diabetes (T2D) and overweight or obesity. We examined the impact of randomization to an intensive lifestyle intervention (ILI) on trajectories of cognitive function over 10 years in a cohort of participants in a randomized clinical trial who had T2D and overweight/obesity at baseline. Methods: Participants aged 45–76 years were enrolled in 2001–2004 and were randomized to the ILI or a diabetes support and education (DSE) condition. Cognitive function was assessed in 3,938 participants at up to 4 time points 8–18 years after randomization. General linear mixed effects models examined cognitive trajectories over time. Subgroup analyses focused on sex, individuals with baseline body mass index >30, those carrying the APOE ε4 allele, and those with a baseline history of cardiovascular disease (CVD). Results: Overall, there were no differences in the rate of cognitive decline by intervention arm. Subgroup analyses showed that participants who had a baseline history of CVD and were randomized to the ILI arm of the study performed significantly worse on the Stroop Color Word Test than those in the DSE arm. Discussion/Conclusions: The ILI did not result in preserved cognitive function or slower rates of cognitive decline in this cohort of individuals who had T2D and were overweight or obese at baseline.

Longitudinal Association of Total Tau Concentrations and Physical Activity With Cognitive Decline in a Population Sample

Tau is a brain protein located in neurons and develops abnormally in individuals with Alzheimer disease. New technology is convenient for measuring blood total tau concentrations and provides a unique and increased opportunity for early intervention to slow cognitive decline. To evaluate the association of physical activity and total tau concentrations with cognitive decline at baseline and over time. The Chicago Health and Aging Project is a population-based cohort study conducted in 4 Chicago communities. Data collection occurred in 3-year cycles between 1993 and 2012. Participants completed in-home interviews. Clinical evaluations, which included blood samples, were performed with a stratified random sample of 1159 participants. Statistical analyses were conducted from October 30, 2020, to May 25, 2021. Physical activity and total serum tau concentrations. Data on physical activity were obtained through self-report items, and a sum of minutes per week was calculated. Little physical activity was defined as no participation in a minimum of 4 of the items on the physical activity measure. Medium activity was defined as participating in less than 150 minutes of physical activity per week, and high activity was defined as participating in 150 minutes or more of physical activity per week. The main outcome for this study is global cognitive function, measured through a battery of cognitive tests. The study hypothesis was developed after data were collected. Of the 1159 participants in the study, 728 were women (63%), and 696 were African American (60%); the mean (SD) age was 77.4 (6.0) years, and the mean (SD) educational level was 12.6 (3.5) years. Participants with high total tau concentrations with medium physical activity had a 58% slower rate of cognitive decline (estimate, -0.028 standard deviation unit [SDU] per year [95% CI, -0.057 to 0.002 SDU per year]; difference, 0.038 SDU per year [95% CI, 0.011-0.065 SDU per year]), and those with high physical activity had a 41% slower rate of cognitive decline (estimate, -0.038 SDU per year [95% CI, -0.068 to -0.009 SDU per year]; difference, 0.027 SDU per year [95% CI, -0.002 to 0.056 SDU per year]), compared with those with little physical activity. Among participants with low total tau concentrations, medium physical activity was associated with a 2% slower rate of cognitive decline (estimate, -0.050 SDU per year [95% CI, -0.069 to -0.031 SDU per year]; difference, 0.001 SDU per year [95% CI, -0.019 to 0.021 SDU per year]), and high physical activity was associated with a 27% slower rate of cognitive decline (estimate, -0.037 SDU per year [95% CI, -0.055 to -0.019 SDU per year]; difference, 0.014 SDU per year [95% CI, -0.007 to 0.034 SDU per year]), compared with little physical activity. Individual tests of cognitive function showed similar results. This study suggests that, among participants with both high and low total tau concentrations, physical activity was associated with slower cognitive decline. Results support the potential utility of blood biomarkers in measuring the benefits associated with health behaviors and may contribute to specifying target populations or informing interventions for trials that focus on improving physical activity behavior. Future work should examine the association of total tau concentrations with other health behaviors and physical activity types.

Omega-3 fatty acids are associated with blood-brain barrier integrity in a healthy aging population.

In aging populations, omega‐3 polyunsaturated fatty acids (PUFAs) have been associated with better cognitive function, slower rates of cognitive decline, and lower risk of developing dementia. Animal studies have shown that diets rich in omega‐3 PUFAs reduce blood–brain barrier (BBB) disruption associated with aging, but this has yet to be observed in humans.Forty‐five healthy subjects (mean age, 76 years) were recruited and underwent cognitive assessment (verbal learning and memory, language, processing speed, executive function, and motor control) and measurement of PUFAs. Forty of the same subjects also underwent magnetic resonance imaging (MRI) to measure BBB integrity (K trans using dynamic contrast‐enhanced MRI).The long chain omega‐3 score (DHA+EPA) was negatively correlated with K trans values in the internal capsule, indicating higher omega‐3 levels were associated with greater BBB integrity in this region (r = –0.525, p = .004). Trends were observed for a positive correlation between the long chain omega‐3 score and both memory and language scores, but not with executive function, speed, or motor control. The omega‐6 score was not significantly correlated with any cognitive scores or K trans values.The significant correlations between long chain omega‐3 levels and BBB integrity provide a possible mechanism by which omega‐3 PUFAs are associated with brain health.

Duration of subjective poverty in relation to subsequent cognitive performance and decline among adults aged ≥64 in China, 2005–2018

BackgroundThe effects of late-life subjective poverty on brain health are understudied. We aimed to investigate the association between duration of subjective poverty after age 64 and subsequent cognitive function and decline in China. MethodsData were from 4118 adults aged ≥64 at baseline in the population-based China Longitudinal Healthy Longevity Survey (CLHLS), 2005–2018. The duration of subjective poverty was measured from self-rated economic status relative to neighbors in 2005, 2008, and 2011 (never; one time point; two or three time points). Cognitive function was assessed by the Chinese Mini-Mental State Exam (CMMSE; range: 0–30) in 2011, 2014, and 2018. We fitted attrition-weighted, multivariable mixed-effects Tobit regression models to examine the relationship between duration of subjective poverty from 2005 to 2011 and subsequent cognitive function and decline from 2011 to 2018. ResultsA total of 2675 (64.96%) participants never reported subjective poverty over the period 2005–2011, 930 (22.58%) participants reported subjective poverty at one time point, and 513 (12.46%) reported subjective poverty at two or three time points. Compared to those who never reported subjective poverty, participants experiencing subjective poverty at one time point (β = −0.95, 95% CI: −1.48 to −0.41) and two or three time points (β = −2.01; 95% CI: −2.73 to −1.29) had lower CMMSE scores in 2011, indicating a dose-response relationship. Individuals with a longer duration of subjective poverty had a slower rate of decline in CMMSE scores than those never in subjective poverty (β = 1.44; 95% CI: 0.20 to 2.68 for 2018 X Two or three time points). ConclusionSubjective poverty in late life may have unique and cumulative contributions to cognitive aging among older adults in China. The lower level of initial cognitive function but slower rate of cognitive decline observed for those with greater subjective poverty is consistent with theories of cognitive reserve and empirical evidence from Western settings on other socioeconomic markers.

A national longitudinal study of marital quality and cognitive decline among older men and women

We provide one of the first national longitudinal studies of the association between trajectories of marital quality and cognitive functioning among older adults, with close attention paid to gender differences. Data were drawn from the Health and Retirement Study (HRS) 2006–2016. Marital quality trajectories were assessed at three waves: 2006/2008, 2010/2012, and 2014/2016. Cognitive trajectories were assessed at five waves: 2008, 2010, 2012, 2014, and 2016. The final analytic sample included 7901 respondents age 50 and older (4334 men and 3567 women) who were either married or cohabiting during the study period. Results from parallel linear growth curve models suggest that among older adults, initial positive marital quality was associated with better initial cognition, and initial negative marital quality was associated with worse initial cognition. Results from multiple group analysis further suggest that marital quality was significantly associated with men's cognitive trajectories but not women's. Among men, an increase in positive marital quality was associated with a slower rate of cognitive decline, whereas an increase in negative marital quality was associated with a faster rate of cognitive decline. These findings suggest that older men who experience a decline in marital quality may be vulnerable to cognitive decline and that reducing marital strain and improving marital quality may protect men's cognitive health in later life.