Cognitive profiles are associated with brain morphometry years later in Hispanics/Latinos: Preliminary findings from the SOL‐INCA‐MRI study

Abstract

AbstractBackgroundHispanics/Latinos are the largest and most diverse ethnoracial group at high risk for Alzheimer’s disease and related dementias across the US. However, this population is largely understudied. We present preliminary findings on the association between cognitive profiles and brain morphometry measures in a large Hispanic/Latino cohort of older adults.MethodWe used a longitudinal cohort of cognitively normal older adults (n = 2028; mean baseline age = 54.19 (6.75) years, 69.5% female) from the Study of Latinos‐Investigation of Neurocognitive Aging‐Magnetic Resonance Imaging (SOL‐INCA‐MRI). First, to establish a latent memory variable, we examined confirmatory factor analysis to test loadings of four manifest variables (Spanish‐English‐Verbal‐Learning Test learning and recall, digit symbol, word frequency) at the first (2008‐2015) and second (2015‐2021) cognitive visits. Second, we examined whether tertiles of our latent cognitive score were associated with two measures of brain integrity (white matter hyperintensities [WMH] and hippocampus) measured between 2018‐2022. The brain morphometry measures were regressed independently on cognitive tertiles at both visits. Age at each visit, sex, education, Hispanic/Latino background, and cognitive‐MRI lag time were included as covariates.ResultFirst, a two‐factor latent memory profile (episodic memory and working memory) best represented our four manifest variables at both visits 1 and 2. Each tertile corresponded to low (1), intermediate (2), and high (3) performing groups. Second, increase in cognitive tertile (from low to intermediate to high) on episodic memory (β = ‐0.157, SE = 0.040, p< 0.001) and working memory (β = ‐0.192, SE = 0.043, p< 0.001) at visit 1 was associated with lower WMH. Increase in cognitive tertile on episodic and working memory at visit 2 was associated with lower WMH (β = ‐0.241, SE = 0.036, p< 0.001 and β = ‐0.260, SE = 0.043, p< 0.001, respectively) and greater hippocampus (β = 0.051, SE = 0.015, p = 0.001 and β = 0.040, SE = 0.018, p = 0.025, respectively).ConclusionOur preliminary findings showed that cognitive profiles and key brain integrity measures are associated years later in Hispanic/Latino adults. Careful monitoring of cognitive aging profiles in the Hispanic/Latino community may lead to early detection and intervention of older adults at high risk for future neurodegeneration.