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Background subjective cognitive decline (SCD) refers to the subjective experience of cognitive decline in the absence of detectable cognitive impairment. SCD has been largely studied as a risk condition for cognitive decline. Empirical observations suggest that persons with SCD are heterogeneous, including individuals with early Alzheimer's disease and others with psychological vulnerabilities and/or physical comorbidity. The semiology of SCD is still in its infancy, and the features predicting cognitive decline are poorly defined. The present study aims to identify subgroups of SCD using a data-driven approach and study their clinical evolution across 8 years. Methods the study population is the InveCe.Ab population-based cohort, including cognitively unimpaired people aged 70–74 years and followed for 8 years. Hierarchical cluster analysis (HCA) was carried out to identify distinct SCD subgroups based on nine clinical and cognitive features. Longitudinal changes by baseline SCD status were estimated using linear mixed models for cognitive decline and Cox proportional-hazard model for all-cause dementia risk. Results out of 956 individuals, 513 were female (54%); and the mean age was 72.1 (SD = 1.3), education was 7.2 (3.3), and 370 (39%) reported cognitive complaints (SCD). The HCA resulted in two clusters (SCD1 and SCD2). SCD2 were less educated and had more comorbidities, cardiovascular risk and depressive symptoms than SCD1 and controls. SCD2 presented steeper cognitive decline (Mini-Mental State Examination; β  = −0.31) and increased all-cause dementia risk (hazard-ratio = 3.4). Conclusions at the population level, basic clinical information can differentiate individuals with SCD at higher risk of developing dementia, underlining the heterogeneous nature of this population even in a sample selected for a narrow age range, in a specific geographic area. [ABSTRACT FROM AUTHOR]

Background The prevalence of dementia varies around the world, potentially contributed to by international differences in rates of age-related cognitive decline. Our primary goal was to investigate how rates of age-related decline in cognitive test performance varied among international cohort studies of cognitive aging. We also determined the extent to which sex, educational attainment, and apolipoprotein E [epsilon]4 allele (APOE*4) carrier status were associated with decline. Methods and findings We harmonized longitudinal data for 14 cohorts from 12 countries (Australia, Brazil, France, Greece, Hong Kong, Italy, Japan, Singapore, Spain, South Korea, United Kingdom, United States), for a total of 42,170 individuals aged 54-105 y (42% male), including 3.3% with dementia at baseline. The studies began between 1989 and 2011, with all but three ongoing, and each had 2-16 assessment waves (median = 3) and a follow-up duration of 2-15 y. We analyzed standardized Mini-Mental State Examination (MMSE) and memory, processing speed, language, and executive functioning test scores using linear mixed models, adjusted for sex and education, and meta-analytic techniques. Performance on all cognitive measures declined with age, with the most rapid rate of change pooled across cohorts a moderate -0.26 standard deviations per decade (SD/decade) (95% confidence interval [CI] [-0.35, -0.16], p < 0.001) for processing speed. Rates of decline accelerated slightly with age, with executive functioning showing the largest additional rate of decline with every further decade of age (-0.07 SD/decade, 95% CI [-0.10, -0.03], p = 0.002). There was a considerable degree of heterogeneity in the associations across cohorts, including a slightly faster decline (p = 0.021) on the MMSE for Asians (-0.20 SD/decade, 95% CI [-0.28, -0.12], p < 0.001) than for whites (-0.09 SD/decade, 95% CI [-0.16, -0.02], p = 0.009). Males declined on the MMSE at a slightly slower rate than females (difference = 0.023 SD/decade, 95% CI [0.011, 0.035], p < 0.001), and every additional year of education was associated with a rate of decline slightly slower for the MMSE (0.004 SD/decade less, 95% CI [0.002, 0.006], p = 0.001), but slightly faster for language (-0.007 SD/decade more, 95% CI [-0.011, -0.003], p = 0.001). APOE*4 carriers declined slightly more rapidly than non-carriers on most cognitive measures, with processing speed showing the greatest difference (-0.08 SD/decade, 95% CI [-0.15, -0.01], p = 0.019). The same overall pattern of results was found when analyses were repeated with baseline dementia cases excluded. We used only one test to represent cognitive domains, and though a prototypical one, we nevertheless urge caution in generalizing the results to domains rather than viewing them as test-specific associations. This study lacked cohorts from Africa, India, and mainland China. Conclusions Cognitive performance declined with age, and more rapidly with increasing age, across samples from diverse ethnocultural groups and geographical regions. Associations varied across cohorts, suggesting that different rates of cognitive decline might contribute to the global variation in dementia prevalence. However, the many similarities and consistent associations with education and APOE genotype indicate a need to explore how international differences in associations with other risk factors such as genetics, cardiovascular health, and lifestyle are involved. Future studies should attempt to use multiple tests for each cognitive domain and feature populations from ethnocultural groups and geographical regions for which we lacked data., Author(s): Darren M. Lipnicki 1, John D. Crawford 1, Rajib Dutta 1, Anbupalam Thalamuthu 1, Nicole A. Kochan 1, Gavin Andrews 1, M. Fernanda Lima-Costa 2, Erico Castro-Costa 2, Carol [...]

The study aimed to evaluate the short-term efficacy of social network sites (SNSs) training on cognitive performance in cognitively healthy older individuals, and to explore the influence of personality traits on cognitive benefits of SNSs training. The Aging in a Networked Society-Social Experiment study was a randomized controlled trial with three arms: intervention group (course on SNSs use), active control group (lifestyle education) and waiting list. Among the 180 eligible participants, 144 participated, 115 completed the study. The assessment comprised: Stroop Color and Word Test, Wechsler tests (Digit span, Symbol search, Coding), and Eysenck Personality Questionnaire- Revised- Short Form. There was no significant cognitive improvement for treatment group versus the control groups. Time interference significantly worsened in lifestyle education group compared to the waiting list, after controlling for baseline test scores and personality traits. The present study does not support the usefulness of SNSs training with healthy older adults. The educational content of lifestyle education is not an inert condition among individuals with high levels of neuroticism and socially desirable responding. There is a need to design experimental conditions in the control groups which do not influence participant's outcomes. [ABSTRACT FROM AUTHOR]

Few studies have examined lockdown effects on the way of living and well-being of older adults stratified by cognitive state. Since cognitive deficits are common in this population, we investigated how cognition influenced their understanding of the pandemic, socio-behavioral responses and lifestyle adaptations during lockdown, and how these factors affected their mood or memory. Telephone-based survey involving 204 older adults ≥65 y/o (median: 82) with previous assessments of cognitive state: 164 normal-old (NOLD), 24 mild-neurocognitive disorder (mild-NCD), 18 mild-moderate dementia. A structured questionnaire was developed to assess psychological and socio-behavioral variables. Logistic regression was used to ascertain their effects on mood and memory. With increasing cognitive deficits, understanding of the pandemic and the ability to follow lockdown policies, adapt to lifestyle changes, and maintain remote interactions decreased. Participants with dementia were more depressed; NOLDs remained physically and mentally active but were more bored and anxious. Sleeping and health problems independently increased the likelihood of depression (OR: 2.29; CI: 1.06–4.93; p = 0.034 and OR: 2.45; CI: 1.16–5.16; p = 0.018, respectively); Regular exercise was protective (OR: 0.30; CI: 0.12–0.72; p = 0.007). Worsening subjective memory complaints were associated with dementia (p = 0.006) and depression (p = 0.004); New-onset sleeping problems raised their odds (OR: 10.26; CI: 1.13–93.41; p = 0.039). Finally, >40% with health problems avoided healthcare mainly due to fear of contagion. NOLD and mild-NCD groups showed similar mood-behavioral profiles suggesting better tolerance of lockdown. Those with dementia were unable to adapt and suffered from depression and cognitive complaints. To counteract lockdown effects, physical and mental activities and digital literacy should be encouraged. [ABSTRACT FROM AUTHOR]

Aims: Perilipins are conserved proteins that decorate intracellular lipid droplets and are essential for lipid metabolism. To date, there is limited knowledge on their expression in human brain or their involvement in brain aging and neurodegeneration. The aim of this study was to characterise the expression levels of perilipins (Plin1–Plin5) in different cerebral areas from subjects of different age, with or without signs of neurodegeneration. Methods: We performed real‐time RT‐PCR, western blotting, immunohistochemistry and confocal microscopy analyses in autoptic brain samples of frontal and temporal cortex, cerebellum and hippocampus from subjects ranging from 33 to 104 years of age, with or without histological signs of neurodegeneration. To test the possible relationship between Plins and inflammation, correlation analysis with IL‐6 expression was also performed. Results: Plin2, Plin3 and Plin5, but not Plin1 and Plin4, are expressed in the considered brain areas with different intensities. Plin2 appears to be expressed more in grey matter, particularly in neurons in all the areas analysed, whereas Plin3 and Plin5 appear to be expressed more in white matter. Plin3 seems to be expressed more in astrocytes. Only Plin2 expression is higher in old subjects and patients with early tauopathy or Alzheimer's disease and is associated with IL‐6 expression. Conclusions: Perilipins are expressed in human brain but only Plin2 appears to be modulated with age and neurodegeneration and linked to an inflammatory state. We propose that the accumulation of lipid droplets decorated with Plin2 occurs during brain aging and that this accumulation may be an early marker and initial step of inflammation and neurodegeneration. [ABSTRACT FROM AUTHOR]

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]