Beyond Hypertension: Examining Variable Blood Pressure's Role in Cognition and Brain Structure

Area of Science:

• Neurology
• Gerontology
• Cardiovascular Health

Background:

• Hypertension is a modifiable risk factor for dementia, contributing to 40% of cases.
• While hypertension is linked to cognitive decline and brain changes, the long-term effects of blood pressure variability are less understood.

Purpose of the Study:

• To investigate the association between variable blood pressure (BP) and longitudinal changes in cognition, brain structure (white matter hyperintensities, gray matter, and white matter volume), and postmortem neuropathology.
• To compare the effects of normal, high, and variable BP on cognitive and brain health over time.

Main Methods:

• Analysis of 4,606 participants from RADC RUSH and 2,114 from ADNI, with a total of 42,603 follow-ups.
• Participants categorized into normal, high, or variable BP groups.
• Linear-mixed models used to assess relationships between BP, cognition, brain structure, and neuropathology.

Main Results:

• Older adults with variable BP showed the most rapid cognitive decline, followed by high BP, then normal BP.
• Variable BP was associated with increased gray matter volume loss and white matter hyperintensity burden compared to high and normal BP.
• Postmortem analysis revealed higher neuropathology rates in both variable and high BP groups versus normal BP.

Conclusions:

• Variable BP may diminish resilience to dementia-related pathology and poses a greater dementia risk than high BP alone.
• Effective management of variable BP is crucial for reducing cognitive decline in the elderly population.
• Findings were consistent across both study cohorts, indicating generalizability.