Association of Hispanic/Latino background and brain structure in Hispanics/Latinos from the SOL‐INCA MRI study

Abstract

AbstractBackgroundThe Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a representative, community‐based study of Hispanics and Latinos across the US that seeks to understand health disparities within this heterogeneous population. The Study of Latinos ‐ Investigation of Neurocognitive Aging MRI (SOL‐INCA MRI) is an ancillary MRI study to HCHS/SOL focused on the genetic influence and cognitive impact of age‐ and disease‐related brain measures. Brain structure undergoes substantial development and remodeling from birth through adulthood. Intracranial volume is a measure of maximum brain development, which is under substantial genetic and environmental influences, and is an independent marker of cognitive resilience. We report the influence of self‐described background on intracranial volume, brain tissue and cortical thickness measures for 1388 individuals studied to date.MethodHispanics and Latinos (ages 35.9‐85.2 years; 66% female) underwent MRI and analysis at the Imaging of Dementia and Aging (IDeA) laboratory using previously published methods. MRI outcomes of interest included supratentorial intracranial volume (TCV), image segmentation into white matter, gray matter, total brain, and regional cortical thickness. Background was categorized as Cuban, Central American, Dominican, Mexican, Puerto Rican and South American. We performed association analysis using linear regression models accounting for sex, height, background, and their interactions.ResultHeight was positively associated with TCV. Women had significantly smaller TCV than men (Table 1). TCV did not vary significantly with age. After adjusting for age, gender, height, and interactions, TCV measures varied significantly by background, and were greatest for Dominicans. Cuban’s and Mexican’s TCV measures were significantly smaller than Dominican’s (Figure 1). Cerebral gray matter volume as a residual of TCV was also significantly greater for Dominicans as compared to all other backgrounds (Table 2). Residuals of brain, gray and white matter varied significantly across backgrounds (Figure 2). Finally, cortical thickness measures varied significantly by background and brain region, being greatest for both Dominicans and Puerto Ricans (Figure 3).ConclusionBrain development results from multiple factors including gene, environment, and gene‐environment interactions. Investigating the genetic and environmental causes of the heterogeneity of brain measures in SOL‐INCA‐MRI are likely to lead to discoveries related to both brain development and possibly brain aging.