Association of Cardiovascular Health With Brain Volume and White Matter Integrity: Results of the SOL-INCA MRI Study.

Background and objectives: Better cardiovascular health (CVH), measured using the Life's Simple 7 (LS7) score, is associated with improved cognitive function. However, its effect on brain imaging in Hispanics/Latinos has not been reported. We investigated the association of LS7 score with brain MRI outcomes in a diverse Hispanic/Latino population.

Methods: Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is the largest prospective cohort study of diverse Hispanic/Latino adults in the United States. LS7 score was assessed at baseline (2008-2011). The SOL-Investigation of Neurocognitive Aging (SOL-INCA) MRI ancillary study recruited HCHS/SOL participants who underwent neuroimaging approximately 10 years (2017-2022) later. Main outcomes include standardized residuals for total brain, total and lobar gray matter (frontal, temporal, parietal, and occipital), total white matter, total CSF, lateral ventricle (LV), and white matter hyperintensity (WMH) volumes and diffusion tensor imaging (mean free water fraction, peak width skeletonized mean diffusivity, and mean fractional anisotropy). MRI outcomes across continuous LS7 scores were investigated using adjusted linear regression models. We performed an interaction analysis by age and sex. All analyses accounted for complex sample design.

Results: The study included 2,659 participants (weighted %female = 56%). The mean age (95% CI) was 54 (53-55) years, and the mean LS7 score was 7.2 (7.1-7.3). In the fully adjusted model, higher LS7 scores were associated with larger total and lobar brain volumes (β_{Total Brain} = 0.03 [0.002 to 0.06], β_{Total White} = 0.05 [0.03 to 0.08], β_{Total Gray} = 0.04 [0.01 to 0.06], β_{Frontal Gray} = 0.04 [0.02 to 0.07]); smaller total CSF (β = -0.06 [-0.08 to -0.03]), LV (β = -0.03 [-0.06 to -0.004]), and WMH (β = -0.05 [-0.07 to -0.03]) volumes; and better measures of microstructural integrity (β_FW = -0.002 [-0.003 to -0.001], β_PSMD = -0.01 [-0.01 to -0.003], and β_FA = 0.001 [0.001 to 0.002]). In interaction analysis by age, the benefits of CVH on magnetic resonance volumes and microstructural integrity were more pronounced in older patients. No interaction was observed by sex.

Discussion: We found that better CVH is associated with better brain-based volumes and microstructural integrity and that the effects of LS7 score on brain health are age dependent. Additional studies are needed to assess the longitudinal effect of CVH on MR-based brain health outcomes.