Which blood pressure measure was linked to changes in brain white matter in older people?

Details

High blood pressure is a risk factor for cerebrovascular disease, including stroke. Little is known about its importance in the progression of brain microvascular disease, which has been associated with declines in mobility and cognition in older people.

This prospective cohort study examined relationships among vascular risk factors, white matter hyperintensity volume, and functional status in people aged 75 to 89. Researchers enrolled 99 participants using a balanced 3×3 matrix stratified by age and mobility performance; 72 completed all baseline and two-year follow-up studies. People were excluded if medications or systemic or neurological diseases could compromise their mobility.

At baseline and after 24 months, researchers performed ambulatory and clinic blood pressure monitoring, magnetic resonance imaging, gait studies, and neuropsychological testing. They used semiautomated segmentation to classify brain tissue into normal white matter and T2-hyperintense white matter hyperintensity volume. They also obtained quantitative measures of mobility and cognitive function over time.

An increase in ambulatory systolic blood pressure from baseline to 24 months, but not an increase in clinic systolic blood pressure, was associated with an increase in white matter hyperintensity volume over the same period and with measures of executive function and processing speed. Similar associations were observed for 24-hour, awake, and sleep blood pressure, but not for the surge between sleep and awake time at the 24-month assessment.

The authors concluded that the findings demonstrate, for the first time, the importance of 24-hour systolic blood pressure in the progression of white matter hyperintensity volume burden associated with cognitive impairment in older people. They proposed 24-hour systolic blood pressure as a potential intervention target to reduce brain vascular disease and functional impairment in older people.