Cumulative blood pressure exposure and cognition: the potential mediating role of brain volume.

Elevated blood pressure (BP) has been linked to brain structure changes and cognitive decline. However, few studies have accounted for long-term cumulative BP exposure. We investigated the association between cumulative BP exposure, brain volume, cerebral blood flow (CBF), and cognitive decline. Furthermore, we explored whether alterations in brain volume and CBF mediated the association between cumulative BP and cognitive decline. We included 1012 adult participants from the Kailuan study. Cumulative BP exposure was calculated from 2006 to 2020. Brain MRI scans and the Montreal Cognitive Assessment (MoCA) were performed in 2020. Generalized linear regression models were used to investigate the associations between cumulative BP, brain volume, CBF, and cognitive function. Mediation analysis was performed to examine whether alterations in brain volume and CBF mediated the association between cumulative BP and cognitive decline. Compared with the lowest tertiles, the highest tertiles of cumulative SBP were associated with lower volumes in total brain (-9.11 [-16.25, -1.97]), total GM (-5.53 [-10.02, -1.04]), frontal lobe (-2.46 [-4.15, -0.78]), temporal lobe (-1.37 [-2.51, -0.23]) and hippocampus (-0.15 [-0.26, -0.03]), and the highest tertiles of cumulative DBP were associated with lower volume in frontal lobe (-2.33 [-3.98, -0.68]) and temporal lobe (-1.15 [-2.27, -0.04]). Higher cumulative SBP and DBP were associated with lower total and regional CBF and MoCA scores (all P < 0.05). The associations between cumulative DBP and cognitive decline were mediated by the volumes in total GM, frontal lobe and temporal lobe. Early intervention in cumulative BP may help preserve brain structure and function.