Abstract 13302: Associations of Allostatic Load With Brain Macro-Morphology, Subclinical Cerebrovascular Disease, and Microstructural Integrity of White Matter Pathways: The Boston Puerto Rican Health Study

Abstract

Introduction: Allostatic load (AL), a measure of overall body wear and tear, has been associated with structural and functional alterations of the brain, but the evidence remains scarce. We aimed to evaluate the prospective associations of AL with brain MRI measures in the Boston Puerto Rican Health Study (BPRHS). Research Questions: Whether AL is associated with 1) brain macro-morphology: brain age and volumes, 2) subclinical cerebrovascular disease: white matter hyperintensity (WMH) and brain infarcts, and 3) microstructural integrity of white matter (WM) pathways in Puerto Rican adults. Methods: Adults from the BPRHS cohort who provided blood and urine samples at baseline, 2-y, and 6-y visits and underwent MRI scans at 13-y visit were included in analyses (n=226). AL was evaluated as a composite score (0-11) of 11 physiological parameters in five body systems. An overall AL score was calculated by averaging the scores of the baseline, 2-y, and 6-y visits, with higher scores indicating greater dysregulation. We evaluated brain age and volumes using T1-weighted MRI, WMH and brain infarcts using T2-weighted MRI, and microstructural integrity of WM pathways using diffusion tensor imaging. Multivariable logistic regression models were used to examine the associations between AL and brain infarcts, and linear regression models were used for other MRI outcomes. Results: Mean age at baseline was 54.6 ± 6.6 y, with 79.2% female. Higher AL was associated with higher brain age z scores (β = 0.129, P = 0.031) and lower volumes of total WM, cerebral WM (especially parietal and temporal lobes), cerebellum, and brain stem. Higher AL was also associated with higher grades of WMH (β = 0.207, P = 0.024) and higher odds of small vessel infarcts [OR (95% CI) = 3.50 (1.56-7.87), P = 0.002], but not large vessel infarcts [OR (95% CI) = 1.33 (0.73-2.40), P = 0.348]. Diffusion tensor imaging parameters showed that participants with higher AL had more microstructural deterioration patterns in major WM pathways. Conclusions: Higher AL score was associated with brain macro- and microstructural disruptions and a higher risk of subclinical cerebrovascular disease, suggesting that AL may be a potential indicator of the need for early intervention in preventing neuronal damage in older adults.