Search

IntroductionThough consistent evidence suggests that physical activity may delay dementia onset, the duration and amount of activity required remains unclear.MethodsWe harmonized longitudinal data of 11,988 participants from 10 cohorts in eight countries to examine the dose-response relationship between late-life physical activity and incident dementia among older adults.ResultsUsing no physical activity as a reference, dementia risk decreased with duration of physical activity up to 3.1 to 6.0 hours/week (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.67 to 1.15 for 0.1 to 3.0 hours/week; HR 0.68, 95% CI 0.52 to 0.89 for 3.1 to 6.0 hours/week), but plateaued with higher duration. For the amount of physical activity, a similar pattern of dose-response curve was observed, with an inflection point of 9.1 to 18.0 metabolic equivalent value (MET)-hours/week (HR 0.92, 95% CI 0.70 to 1.22 for 0.1 to 9.0 MET-hours/week; HR 0.70, 95% CI 0.53 to 0.93 for 9.1 to 18.0 MET-hours/week).DiscussionThis cross-national analysis suggests that performing 3.1 to 6.0 hours of physical activity and expending 9.1 to 18.0/MET-hours of energy per week may reduce dementia risk.

BackgroundWe examined how the relationship between education and latelife cognitive impairment (defined as a Mini Mental State Examination score below 24) is influenced by age, sex, ethnicity, and Apolipoprotein E epsilon 4 (APOE*4).MethodsParticipants were 30,785 dementia-free individuals aged 55-103 years, from 18 longitudinal cohort studies, with an average follow-up ranging between 2 and 10 years. Pooled hazard ratios were obtained from multilevel parametric survival analyses predicting cognitive impairment (CI) from education and its interactions with baseline age, sex, APOE*4 and ethnicity. In separate models, education was treated as continuous (years) and categorical, with participants assigned to one of four education completion levels: Incomplete Elementary; Elementary; Middle; and High School.ResultsCompared to Elementary, Middle (HR = 0.645, P = 0.004) and High School (HR = 0.472, P

We aimed to examine the relationship between Apolipoprotein E ε4 (APOE*4) carriage on cognitive decline, and whether these associations were moderated by sex, baseline age, ethnicity, and vascular risk factors. Participants were 19,225 individuals aged 54-103 years from 15 longitudinal cohort studies with a mean follow-up duration ranging between 1.2 and 10.7 years. Two-step individual participant data meta-analysis was used to pool results of study-wise analyses predicting memory and general cognitive decline from carriage of one or two APOE*4 alleles, and moderation of these associations by age, sex, vascular risk factors, and ethnicity. Separate pooled estimates were calculated in both men and women who were younger (ie, 62 years) and older (ie, 80 years) at baseline. Results showed that APOE*4 carriage was related to faster general cognitive decline in women, and faster memory decline in men. A stronger dose-dependent effect was observed in older men, with faster general cognitive and memory decline in those carrying two versus one APOE*4 allele. Vascular risk factors were related to an increased effect of APOE*4 on memory decline in younger women, but a weaker effect of APOE*4 on general cognitive decline in older men. The relationship between APOE*4 carriage and memory decline was larger in older-aged Asians than Whites. In sum, APOE*4 is related to cognitive decline in men and women, although these effects are enhanced by age and carriage of two APOE*4 alleles in men, a higher numbers of vascular risk factors during the early stages of late adulthood in women, and Asian ethnicity.

BackgroundWith no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups.Methods and findingsWe harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54-105 (mean = 72.7) years and without dementia at baseline. Studies had 2-15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = -0.1, SE = 0.01), APOE*4 carriage (B = -0.31, SE = 0.11), depression (B = -0.11, SE = 0.06), diabetes (B = -0.23, SE = 0.10), current smoking (B = -0.20, SE = 0.08), and history of stroke (B = -0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = -0.07, SE = 0.01), APOE*4 carriage (B = -0.41, SE = 0.18), and diabetes (B = -0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = -0.24, SE = 0.12), and between diabetes and cognitive decline (B = -0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife.ConclusionsThese results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences.

Objectives: The restrictions put in place in 2020 to mitigate the spread of the coronavirus disease 2019 limited or eliminated social connections that are vital for psychosocial well-being. The objectives of this research were to examine the impact of early pandemic-related restrictions on feelings of loneliness, depression, and anxiety as well as social activity disruption and their concomitant associations in a sample of community-dwelling older adults residing in a small-town region in the USA. Design and Setting: Cross-sectional data collected from an ongoing population-based cohort study in Southwestern, Pennsylvania. Participants: Analyses included 360 adults aged 65 years and older whose annual study assessment occurred during the first 120 days of pandemic-related restrictions. Measurements: Self-reported feelings of loneliness, depression, and anxiety due to the pandemic-related restrictions were each measured using a single question. Depressive symptoms and anxiety were also assessed with the modified Center for Epidemiologic Studies-Depression and Generalized Anxiety Disorder-7 item tools. Disruption in a variety of common social activities was also assessed. Results: Feeling lonely affected 36% of participants who were more likely to be female, not currently married, and living alone. Giving up in-person visits with family was associated with significantly higher odds of feeling lonely, and feeling lonely was associated with significantly higher odds of feelings of anxiety and depression. Conclusions: Loneliness is a serious outcome of pandemic-related restrictions among older adults, potentially linked to loss of connection with family, and may be associated with increased feelings of depression and anxiety. [ABSTRACT FROM AUTHOR]

We examined associations between multiple aspects of social resources and 5-year change in performance on different domains of cognitive function. Results indicated that lower satisfaction with support was associated with decline in episodic memory performance over 5 years. We also found significant interactions between age and social networks of family and friends and satisfaction with support for the separate cognitive domains. The results suggest that social resources may be differentially important for cognitive change but that different cognitive domains respond in a similar pattern to social resources. Key Words: Cognition--Social support.

Little is known about potential longitudinal relationships between participation in social, physical, and intellectual activities and later cognitive performance. Data from the Victoria Longitudinal Study (n = 530) were used to test whether baseline and change in lifestyle engagement were related to corresponding indicators of cognitive speed (measured by mean-level and intraindividual variability). Regressions based on random effects model estimates showed that cross-sectional activity participation predicted corresponding values of both mean-level and intraindividual variability, but few longitudinal relationships were significant. Overall, a higher frequency of participation in cognitively complex activities was related to faster response times and lower intraindividual variability. Findings suggest that activity level at one point in time may be a more important predictor of cognition than an individual's changes in activity level.

Background: Education and occupational complexity are main sources of mental engagement during early life and adulthood respectively, but research findings are not conclusive regarding protective effects of these factors against late-life dementia.Objective: This project aimed to examine the unique contributions of education and occupational complexity to incident dementia, and to assess the mediating effects of occupational complexity on the association between education and dementia across diverse cohorts.Method: We used data from 10,195 participants (median baseline age = 74.1, range = 58∼103), representing 9 international datasets from 6 countries over 4 continents. Using a coordinated analysis approach, the accelerated failure time model was applied to each dataset, followed by meta-analysis. In addition, causal mediation analyses were performed.Result: The meta-analytic results indicated that both education and occupational complexity were independently associated with increased dementia-free survival time, with 28%of the effect of education mediated by occupational complexity. There was evidence of threshold effects for education, with increased dementia-free survival time associated with 'high school completion' or 'above high school' compared to 'middle school completion or below'.Conclusion: Using datasets from a wide range of geographical regions, we found that both early life education and adulthood occupational complexity were independently predictive of dementia. Education and occupational experiences occur during early life and adulthood respectively, and dementia prevention efforts could thus be made at different stages of the life course. [ABSTRACT FROM AUTHOR]

Introduction: Although exercise is associated with a lower risk for mild cognitive impairment (MCI), it is unclear whether its protective effect depends on the presence or absence of vascular factors.Methods: In an exploratory study of data from a population-based cohort, 1254 participants aged 65+ years were followed for 10 years for incident MCI. The main effect of baseline total minutes of exercise per week (0 vs. 1 to 149 vs. 150+), and its interaction with several vascular factors, on risk for incident MCI was examined using Cox proportional hazards regression models, adjusting for demographics.Results: Compared with no exercise, 1 to 149 minutes [hazard ratio (HR)=0.90; 95% confidence interval (95% CI), 0.69-1.16] and 150 or more minutes per week (HR=0.84; 95% CI, 0.66-1.07) of exercise lowered risk for incident MCI in a dose-dependent manner. The majority of interactions were not statistically significant, but risk reduction effect sizes of <0.75 suggested that exercise may have stronger effects among those without high cholesterol, never smoking, and not currently consuming alcohol; also, those with arrhythmia, coronary artery disease, and heart failure. Overall, there was a pattern of exercise being associated with lower MCI risk among those without vascular factors.Conclusions: Spending more time engaging in exercise each week may offer protection against MCI in late life, with some variation among those with different vascular conditions and risk factors. Our findings may help target subgroups for exercise recommendations and interventions, and also generate hypotheses to test regarding underlying mechanisms. [ABSTRACT FROM AUTHOR]

Background: Incidence rates of dementia appear to be declining in high-income countries according to several large epidemiological studies. We aimed to describe declining incident dementia rates across successive birth cohorts in a U.S. population-based sample and to explore the influences of sex and education on these trends.Methods: We pooled data from two community-sampled prospective cohort studies with similar study aims and contiguous sampling regions: the Monongahela Valley Independent Elders Survey (1987-2001) and the Monongahela-Youghiogheny Healthy Aging Team (2006-Ongoing). We identified four decade-long birth cohorts spanning birth years 1902-1941. In an analysis sample of 3,010 participants (61% women, mean baseline age = 75.7 years, mean follow-up = 7.1 years), we identified 257 cases of incident dementia indicated by a Clinical Dementia Rating of 1.0 or higher. We used Poisson regression to model incident dementia rates by birth cohort, age, sex, education, and interactions of Sex × Cohort and Sex × Education. We further examined whether cohort effects varied by education, testing a Cohort × Education interaction and stratifying the models by education.Results: Compared to the earliest birth cohort (1902-1911), each subsequent cohort had a significantly lower incident dementia rate (1912-1921: incidence rate ratio [IRR] = 0.655, 95% confidence interval [95% CI] = 0.477-0.899; 1922-1931: IRR = 0.387, 95% CI = 0.265-0.564; 1932-1941: IRR = 0.233, 95% CI = 0.121-0.449). We observed no significant interactions of either sex or education with birth cohort.Conclusions: A decline in incident dementia rates was observed across successive birth cohorts independent of sex, education, and age. [ABSTRACT FROM AUTHOR]

Background/Objective: In population studies, most individuals with mild cognitive impairment (MCI) do not progress to dementia in the near term, but rather remain stable MCI or revert to normal cognition. Here, we characterized MCI subgroups with different outcomes over 5 years. Setting/Participants: A population‐based cohort (N=1603). Measurements: Clinical Dementia Rating (CDR); self‐reported medical conditions, subjective cognitive concerns, self‐rated health, depressive symptoms, blood pressure, medications, blood pressure, APOE genotype, cognitive domain composite scores. Design: We compared 3 MCI subgroups who progressed to dementia (n=86), stabilized at MCI (n=384), or reverted to normal (n=252), to those who remained consistently normal (n=881), defining MCI as CDR = 0.5 and dementia as CDR≥1. Using multinomial logistic regression models adjusted for demographics, we examined the associations of each group with selected baseline characteristics. Results: With the normal group for reference, worse subjective cognitive concerns, functional impairments, self‐rated health, and depressive symptoms were associated with being in any MCI group. Taking more prescription medications was associated with being in the stable MCI and reverter groups; diabetes and low diastolic blood pressure were associated with stable MCI. The APOE4 genotype was associated with stable and progressive MCI; stroke was associated with progressive MCI. All MCI subgroups were likely to have lower mean composite scores in all cognitive domains and more operationally defined impairments in attention, language, and executive function; reverters were more likely to lack memory and visuospatial impairments. Conclusions: MCI subgroups with different 5‐year outcomes had some distinct characteristics suggesting different underlying causes. The progressors, unlike the reverters, had a profile broadly typical of Alzheimer's disease; the stable MCIs had other, including vascular, morbidity. These data shed light on the heterogeneity of MCI in the population. J Am Geriatr Soc 67:232–238, 2019. [ABSTRACT FROM AUTHOR]