The association of childhood socio‐economic position with later life brain structure in individuals of Hispanic/Latino background. Preliminary results from the INCA‐MRI study

Abstract

AbstractBackgroundChildhood is a period of brain plasticity when environmental influences may have long‐lasting effects. Early socio‐economic position (SEP) may influence brain development at vulnerable stages and set the stage for increased vulnerability to Alzheimer’s Disease and related dementias (ADRD). In this study, we evaluated whether childhood SEP was related to brain structure in adulthood.MethodsThis analysis included the first 1320 individuals (61% women, age range 50‐85) of diverse Hispanic/Latino background with brain magnetic resonance imaging (MRI) assessments from the HCHS/SOL INCA‐MRI study, conducted at four major urban areas (Bronx, NY; Chicago, IL; Miami, FL, and San Diego, CA). Childhood SEP was assessed by self‐reported maternal educational achievement. We also calculated the difference between attained height and genetically predicted height using height‐associated SNPs, sex, and genetic ancestry as a biomarker of early environmental exposures. Positive values indicate taller attained stature than the expected based on SNPs, suggesting favorable early environmental influence on height; negative values suggest environmental conditions limiting growth. Measures of brain structure [total intracranial volume (TICV), total gray matter volume (TGMV) and hippocampus volume (HV)] were obtained using MRI with standardized procedures. Survey linear regression models were conducted adjusting for potential confounders.ResultsLow parental educational achievement was common, 55% of mothers completed less than a middle school education. In multivariable linear regression models, higher maternal educational achievement was associated with some measures of brain structure, such as greater TICV (b = 18.6, p<.001 for high school (HS) graduate; b = 26.2, p<.01 for > HS; reference <6 grade), higher TGMV (b = 5.8, p<.02 for HS graduate; b = 5.4, p<.10 for > HS), and higher HV (b = 0.14, p<.01 for HS graduate; b = 0.03, p = NS for greater than HS). Early life factors affecting height were associated with lower TICV (b = ‐18.9, p<.001), lower TGMV (b = ‐6.4, p<.001), and lower HV (b = ‐0.6, p<.01).ConclusionThis study showed associations of early childhood socio‐economic position with brain structure assessed in later adulthood. Findings suggest that height residual is a useful predictor of early life environment affecting later life brain volumes.