The Influence of Birth Weight, Socio-Economic Status, and Adult Health on Brain Volumes during Ageing.

Introduction: Greater late-life brain volumes are associated with resilience against dementia. We examined relationships between birth weight, lifelong socio-economic status, and health with late-life brain volumes. We hypothesised that early life factors directly affect late-life brain volumes.

Methods: Adults aged 59-67 y underwent MRI and brain volumes were measured. Birth weight and lifelong health, and socio-economic status were quantified and the principal components of each extracted. Relationships were examined using regression and structural equation analysis.

Results: Birth weight (β = 0.095, p = 0.017) and childhood socio-economic status (β = 0.091, p = 0.033, n = 280) were directly associated with brain volume. Childhood socio-economic status was further associated with grey matter volume (β = 0.04, p = 0.047). Adult health was linked to increased brain volume (β = 0.15, p = 0.003).

Conclusion: Birth weight and childhood socio-economic status are associated with whole and regional brain volume through direct mechanisms. Optimal fetal development, reduced childhood poverty, and good adult health could reduce brain atrophy and delay dementia onset in late-life.