Abstract 01: Childhood Socioeconomic Position is Associated With Accelerated Brain Aging in U.S Hispanic/Latino Population. Findings From the Hispanic Community Health Study/Study of Latinos

Introduction: Low childhood socioeconomic position (SEP) may have a long-lasting influence on functional and structural brain development. However, little is known about whether early-life SEP is associated with a steeper age-related reduction in measures of brain structure, previously linked to Alzheimer’s Disease and Related Dementias (ADRD) vulnerability. Hypothesis: Low childhood SEP measured by parental education modifies the association between age and magnetic resonance imaging (MRI)-derived brain volumes, with worse age-related brain volumes among adults with low early-life SEP. Methods: We used data from adults (age range 50-85) in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL-INCA-MRI), a population-based cohort study conducted in four major U.S cities. Measures of brain structure (e.g., total brain volume-TBV, total gray matter volume-TGMV, total cortical gray volume-TCGV, hippocampus volume-HV, and white matter hyperintensity volume-WMHV were quantified using MRI in 2400 adults with normal and impaired cognitive function. We used participants' self-reports of the highest education attained by either their father or mother as a proxy for childhood SEP (< high school and ≥ high school). We conducted survey linear regression models of age on brain volumes adjusting for participant’s sex, Hispanic/Latino background, field center, nativity, and age at immigration. We then included interaction terms between age and childhood SEP. Results: In multivariable regression models, older age was associated with smaller brain volumes (β, and 95% confidence interval-CI for TBV for each year increment in age: -3.22, 95% CI: -3.73, -2.71), while older age was associated with larger log-transformed WMHV (β: 0.90, 95% CI: 0.08, 0.10). Childhood SEP modifies the association between age and brain volumes, with significant smaller age-related brain volumes among adults whose parents have less than high school (β for TBV:-3.65, 95% CI: -4.25, -3.04; and TGMV: -1.29, 95% CI: -1.62, -0.95) as compared with those with high school or more (β for TBV: -2.32, 95% CI: -3.17, -1.45; p-value for interaction: 0.024; and TGMV: -0.54, 95% CI: -0.98, -0.10; p-value for interaction: 0.017). These smaller age-related volumes persisted after accounting for participant’s education and income. In contrast, higher childhood SEP was associated with a slightly larger age-related WMHV (β for interaction term: 0.03, 95% CI: 0.01, 0.05, p-value: 0.016). Conclusions: This study highlights the unique contributions of childhood SEP to accelerated brain aging. The age by childhood SEP interaction suggests that childhood socioeconomic disadvantage has a long-lasting influence in accelerated disparities in brain aging as indexed by bran MRI.