Lower Blood Pressure Is Associated With Smaller Subcortical Brain Volumes in Older Persons

Both high and low blood pressure (BP) have been positively as well as negatively associated with brain volumes in a variety of populations. The objective of this study was to investigate whether BP is associated with cortical and subcortical brain volumes in older old persons with mild cognitive deficits.

Within the Discontinuation of Antihypertensive Treatment in the Elderly trial, the cross-sectional relation of BP parameters with both cortical and subcortical brain volumes was investigated in 220 older old persons with mild cognitive deficits (43% men, mean age = 80.7 (SD = 4.1), median Mini-Mental State Examination score = 26 (interquartile range: 25-27)), using linear regression analysis. All analyses were adjusted for age, gender, volume of white matter hyperintensities, and duration of antihypertensive treatment. Brain volumes were determined on 3DT1-weighted brain magnetic resonance imaging scans.

Lower systolic BP, diastolic BP, and mean arterial pressure (MAP) were significantly associated with lower volumes of thalamus and putamen (all P ≤ 0.01). In addition, lower MAP was also associated with reduced hippocampal volume (P = 0.035). There were no associations between any of the BP parameters with cortical gray matter or white matter volume.

In an older population using antihypertensive medication with mild cognitive deficits, a lower BP, rather than a high BP is associated with reduced volumes of thalamus, putamen, and hippocampus.