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

ABSTRACT

OBJECTIVES: Hypertension or high blood pressure (BP) is one of the twelve modifiable risk factors that contribute to 40% of dementia cases that could be delayed or prevented. Although hypertension is associated with cognitive decline and structural brain changes, less is known about the long-term association between variable BP and cognitive/brain changes. This study examined the relationship between variable BP and longitudinal cognitive, white matter hyperintensity (WMH), gray matter (GM), and white matter (WM) volume change over time and post-mortem neuropathology. METHODS: A total of 4,606 participants (32,776 follow-ups) from RADC Research Resource Sharing Hub (RUSH) and 2,114 participants (9,827 follow-ups) from Alzheimer's Disease Neuroimaging Initiative (ADNI) were included. Participants were divided into one of three groups normal, high, or variable BP. Linear mixed models investigated the relationship between BP and cognition, brain structure, and neuropathology. RESULTS: Older adults with variable BP exhibited the highest rate of cognitive decline followed by high and then normal BP. Increased GM volume loss and WMH burden was also observed in variable compared to high and normal BP. In post-mortem neuropathology, both variable and high BP had increased rates compared to normal BP. All the results were consistent across the RUSH and ADNI participants, supporting the generalizability of the findings. DISCUSSION: Damages potentially associated with variable BP may reduce resilience to future dementia related pathology and increased risk of dementia more than that caused by high BP. Improved treatment and management of variable BP may help reduce cognitive decline in the older adult population.