Characterising the covariance pattern between lifestyle factors and structural brain measures: a multivariable replication study of two independent ageing cohorts

Modifiable lifestyle factors have been shown to promote healthy brain ageing. However, studies have typically focused on a single factor at a time. Given that lifestyle factors do not occur in isolation, multivariable analyses may provide a more realistic model of the lifestyle-brain relationship. Here, canonical correlation analysis (CCA) was applied to examine the relationship between nine lifestyle factors and seven MRI-derived indices of brain structure. The resulting covariance pattern was further explored with Bayesian regressions. CCA analyses were first conducted on a Danish cohort of older adults (n=251) and then replicated in a British cohort (n=668). In both cohorts, the latent lifestyle factors were positively associated with the latent structural brain measures (UK: r =0.37, p