Ambulatory blood pressure and the brain

Objective: To determine if initial values of casual and ambulatory systolic blood pressure (SBP) predict white matter hyperintensities, insular subcortex hyperintensities, and brain atrophy 5 years later in a group of healthy elderly individuals. Methods: The authors studied 155 healthy men and women, aged 55 to 79 years. Two 24-hour ambulatory blood pressure (BP) sessions assessed BP level and variability during waking and sleep. Hyperintensities and total brain volume were quantified by MRI. Procedures were repeated 5 years later in 78% (121) of subjects. Results: Hyperintensities and brain atrophy increased over time, with greater increases among older subjects. The presence of increased BP level and variability initially and again 5 years later had negative consequences for the brain. Independent of age, the greater the initial SBP, the greater the likelihood that individuals would have severe white matter hyperintensities after 5 years. Also, elevated casual SBP was associated with severe insular subcortex hyperintensities and greater SBP sleep variability with increased brain atrophy. Conclusions: Among healthy elderly individuals whose initial, average, casual blood pressure (BP) was relatively low (116.9/71.1 mm Hg), small increases in casual and 24-hour ambulatory BP measures were associated with greater brain atrophy and subcortical lesions after 5 years.