Associations between education and brain structure at age 73 years, adjusted for age 11 IQ.

TitleAssociations between education and brain structure at age 73 years, adjusted for age 11 IQ.
Publication TypeJournal Article
Year of Publication2016
AuthorsCox SR, Dickie DAlexander, Ritchie SJ, Karama S, Pattie A, Royle NA, Corley J, Aribisala BS, Hernández MValdés, Maniega SMuñoz, Starr JM, Bastin ME, Evans AC, Wardlaw JM, Deary IJ
JournalNeurology
Volume87
Issue17
Pagination1820-1826
Date Published2016 Oct 25
ISSN1526-632X
Abstract

OBJECTIVE: To investigate how associations between education and brain structure in older age were affected by adjusting for IQ measured at age 11.METHODS: We analyzed years of full-time education and measures from an MRI brain scan at age 73 in 617 community-dwelling adults born in 1936. In addition to average and vertex-wise cortical thickness, we measured total brain atrophy and white matter tract fractional anisotropy. Associations between brain structure and education were tested, covarying for sex and vascular health; a second model also covaried for age 11 IQ.RESULTS: The significant relationship between education and average cortical thickness (β = 0.124, p = 0.004) was reduced by 23% when age 11 IQ was included (β = 0.096, p = 0.041). Initial associations between longer education and greater vertex-wise cortical thickness were significant in bilateral temporal, medial-frontal, parietal, sensory, and motor cortices. Accounting for childhood intelligence reduced the number of significant vertices by >90%; only bilateral anterior temporal associations remained. Neither education nor age 11 IQ was significantly associated with total brain atrophy or tract-averaged fractional anisotropy.CONCLUSIONS: The association between years of education and brain structure ≈60 years later was restricted to cortical thickness in this sample; however, the previously reported associations between longer education and a thicker cortex are likely to be overestimates in terms of both magnitude and distribution. This finding has implications for understanding, and possibly ameliorating, life-course brain health.

DOI10.1212/WNL.0000000000003247
Alternate JournalNeurology
PubMed ID27664981
PubMed Central IDPMC5089529
Grant ListG1001245 / / Medical Research Council / United Kingdom
MR/K026992/1 / / Medical Research Council / United Kingdom
MR/M013111/1 / / Medical Research Council / United Kingdom

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