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Longitudinal observational cohort studies are being conducted worldwide to understand cognition, biomarkers, and the health of the aging population better. Cross-cohort comparisons and networks of registries in Alzheimer's disease (AD) foster scientific exchange, generate insights, and contribute to the evolving clinical science in AD. A scientific working group was convened with invited investigators from established cohort studies in AD, in order to form a research collaboration network as a resource to address important research questions. The Connecting Cohorts to Diminish Alzheimer's Disease (CONCORD-AD) collaboration network was created to bring together global resources and expertise, to generate insights and improve understanding of the natural history of AD, to inform design of clinical trials in all disease stages, and to plan for optimal patient access to disease-modifying therapies once they become available. The network brings together expertise and data insights from 7 cohorts across Australia, Europe, and North America. Notably, the network includes populations recruited through memory clinics as well as population-based cohorts, representing observations from individuals across the AD spectrum. This report aims to introduce the CONCORD-AD network, providing an overview of the cohorts involved, reporting the common assessments used, and describing the key characteristics of the cohort populations. Cohort study designs and baseline population characteristics are compared, and available cognitive, functional, and neuropsychiatric symptom data, as well as the frequency of biomarker assessments, are summarized. Finally, the challenges and opportunities of cross-cohort studies in AD are discussed. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes mellitus (T2DM) is prevalent in the general United States population, and in the veteran population. T2DM has consistently been linked to increased risk for cognitive impairment, dementia, and Alzheimer's disease. Computerized cognitive training (CCT) is practical and inexpensive cognitive interventions that is an alternative to medication.Objective: To report the recruitment methods and challenges to date in an ongoing two-site randomized controlled trial (RCT) of CCT on cognitive function and T2DM management in an older non-demented veteran population.Methods: Veterans are recruited primarily by targeted mailings or by direct contact at clinics and presentations.Results: From 1,459 original contacts, 437 expressed initial interest, 111 provided informed consent, and 97 completed baseline assessments. Participants from the two VA Medical Centers differed in demographics and baseline characteristics. Comparing recruitment methods, the proportion of individuals contacted who were ultimately consented was significantly less from mailings (5%) than other sources (20%), primarily face- to-face clinic visits (χ2 (1) = 38.331, p < 0.001).Conclusions: Mailings are cost-effective, but direct contact improved recruitment. Not using or lacking access to computers and ineligibility were major reasons for non-participation. Within-site comparisons of demographically diverse sites can address confounding of demographic and other site differences. [ABSTRACT FROM AUTHOR]

APOE ℇ4 is a major risk factor for Alzheimer's disease. It has also been associated with cognitive impairment and cognitive decline in young-olds, but the impact of the ℇ4 allele on cognitive function in very late life is still unclear. The object of this study was to evaluate the association of the ℇ4 allele of APOE with the cognitive performance of a sample of non-demented oldest-olds. Eighty-seven Spanish-speaking Puerto Rican non-demented nonagenarians were administered a complete neuropsychological assessment and provided a blood sample used for APOE genotyping. A factor analysis generated two factors: 1) verbal memory; and 2) visuo-spatial, naming and attention tasks, accounting for 43.6% of the overall variance in the 13 original neuropsychological variables. The multivariate analysis reflected, after controlling for gender, education, and age, the APOE ℇ4 carriers performed better in overall cognition (both factors analyzed together) than non-carriers (T^{2} = 0.082, F(2,80) = 3.289, p = 0.042). Neither gender nor the gender by APOE ℇ4 status interaction was associated with differences in cognition. In conclusion, the results of this study suggest that, among these Puerto Rican non-demented nonagenarians, being an APOE ℇ4 allele carrier is associated with better cognition. [ABSTRACT FROM AUTHOR]

APOE epsilon4 is a major risk factor for Alzheimer's disease. It has also been associated with cognitive impairment and cognitive decline in young-olds, but the impact of the epsilon4 allele on cognitive function in very late life is still unclear. The object of this study was to evaluate the association of the epsilon4 allele of APOE with the cognitive performance of a sample of non-demented oldest-olds. Eighty-seven Spanish-speaking Puerto Rican non-demented nonagenarians were administered a complete neuropsychological assessment and provided a blood sample used for APOE genotyping. A factor analysis generated two factors: 1) verbal memory; and 2) visuo-spatial, naming and attention tasks, accounting for 43.6% of the overall variance in the 13 original neuropsychological variables. The multivariate analysis reflected, after controlling for gender, education, and age, the APOE epsilon4 carriers performed better in overall cognition (both factors analyzed together) than non-carriers (T;{2} = 0.082, F(2,80) = 3.289, p = 0.042). Neither gender nor the gender by APOE epsilon4 status interaction was associated with differences in cognition. In conclusion, the results of this study suggest that, among these Puerto Rican non-demented nonagenarians, being an APOE epsilon4 allele carrier is associated with better cognition.