AbstractBackgroundRural communities tend to have higher prevalence of dementia risk factors including cardiovascular diseases and low education. Childhood rural residence has also been associated with worse late life cognition.1 It is unknown if these associations extend to neuroimaging markers of late life brain health.MethodKHANDLE and STAR are harmonized cohorts of racially/ethnically diverse long‐term Kaiser Permanente Northern California members. Regional brain volumes and white matter integrity were measured among a 25% random sample using 3T MRI. Stabilized inverse probability weights were estimated to account for imaging selection based on study, race/ethnicity, baseline age, sex/gender, and geographic region of birth. Rural residence was self‐reported using birth address or imputed from addresses at age 5 (n = 8) or age 10 (n = 1) when missing. MRI measures, except free water fraction and fractional anisotropy, were normalized on intracranial volume. All MRI measures were z standardized. Weighted general linear models tested associations between childhood rurality and MRI measures among those ages 65+. Exploratory models stratified analyses by college degree attainment.ResultCompared to the overall cohort, the imaging sample was slightly younger, had slightly higher educational attainment and was comprised of more males. Imaging participants with a rural childhood were about 1 year older (mean = 76, SD 6.0) and had about ½ year less education (mean = 14.5, SD = 2.4) than the imaging sample overall (Table 1). In weighted linear models (Table 2), childhood rurality was associated with smaller occipital cortex volumes (β = ‐0.25 95% CI = ‐0.50, ‐0.004). In models stratified by education, we observed a non‐significant trend of worse brain health among participants who were college‐educated with rural childhoods (vs. college educated without rural childhoods), that was not present among those without a college degree (Table 3).ConclusionWe observed limited effect of childhood rurality on MRI markers of brain health. Although under‐powered, our analyses suggest that among college educated older adults rural childhoods (vs. non‐rural) may have a negative impact on brain health.Reference:1. Peterson, et. al., (In press: 2023). Rural residence across the lifecourse and late‐life cognitive decline in KHANDLE: A causal inference study. Alzheimer’s and Dementia: Diagnosis, Assessment and Disease Monitoring. https://doi.org/10.1002/dad2.12399