Abstract
Studies exploring age-related brain and cognitive change have identified substantial heterogeneity among individuals, but the underlying reasons for the differential trajectories remain largely unknown. We investigated cross-sectional and longitudinal associations between brain-imaging phenotypes (IDPs) and cognitive ability, and how these relations may be modified by common risk and protective factors. Participants were recruited from the 1953 Danish Male Birth Cohort (N=123), a longitudinal study of cognitive and brain ageing. Childhood IQ and socio-demographic factors are available for these participants who have been assessed regularly on multiple IDPs and behavioural factors in midlife. Using Pearson correlations and canonical correlation analysis (CCA), we explored the relation between 454 IDPs and 114 behavioural variables. CCA identified a single mode of population covariation coupling cross-subject longitudinal changes in brain structure to changes in cognitive performance and to a range of age-related covariates (r=0.92, Pcorrected < 0.001). Specifically, this CCA-mode indicated that; decreases in IQ and speed assessed tasks, higher rates of familial myocardial infarct, less physical activity, and poorer mental health are associated with larger decreases in whole brain grey matter and white matter. We found no evidence supporting the role of baseline scores as predictors of impending brain and behavioural change in late-midlife.
Highlights
Among the many challenges presented by an increasingly “top heavy” Western society, the cases of cognitive decline and the accompanying economic and social demands have never been more apparent [1, 2]
We visualize results with Manhattan plots that show -log 10 p-values for IDP-by-behavioural longitudinal correlations, arranged by behavioural measures on the x-axis, multiple testing thresholds across all pairwise associations are marked with a horizontal line, FWE top line (Puncorrected = 6.01 x 10-6) and False Discovery Rate (FDR) bottom line (Puncorrected = 5.03 x 10-5), Figure 1
The discovery of this canonical correlation analysis (CCA)-mode indicates two key points: First, the results corroborate the existence of a domain-general mechanism that is impaired by normal ageing processes – which in this study is reflected by potential age-related biomarkers and environmental factors to the end effects
Summary
Among the many challenges presented by an increasingly “top heavy” Western society, the cases of cognitive decline and the accompanying economic and social demands have never been more apparent [1, 2]. It is wellestablished that the ageing brain undergoes major structural and functional changes which, even in the absence of disease, is related to decline in specific cognitive domains [3–9] It has been shown www.aging-us.com that on an individual basis, there is significant variability in the trajectories of brain and cognitive change, with a small proportion of the population demonstrating “heathy” or “successful” ageing well into old age [10]. Evidence linking longitudinal brain-cognitive changes to each other and to possible health-related lifestyle behaviours and environmental influencers are limited and inconsistent. In this present study, our first aim was to explore brain-cognitive longitudinal relations. Our second aim was to identify potential risk and protective factors that may contribute to the individual variations observed in later-life brain structure and cognitive functioning
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
