Association of longitudinal changes in 24-h blood pressure level and variability with cognitive decline

A high office blood pressure (BP) is associated with cognitive decline. However, evidence of 24-h ambulatory BP monitoring is limited, and no studies have investigated whether longitudinal changes in 24-h BP are associated with cognitive decline. We aimed to test whether higher longitudinal changes in 24-h ambulatory BP measurements are associated with cognitive decline.

We included 437 dementia-free participants from the Maracaibo Aging Study with prospective data on 24-h ambulatory BP monitoring and cognitive function, which was assessed using the selective reminding test (SRT) and the Mini-Mental State Examination (MMSE). Using multivariate linear mixed regression models, we analyzed the association between longitudinal changes in measures of 24-h ambulatory BP levels and variability with cognitive decline.

Over a median follow-up of 4 years (interquartile range, 2-5 years), longitudinal changes in 24-h BP level were not associated with cognitive function ( P  ≥ 0.09). Higher longitudinal changes in 24-h and daytime BP variability were related to a decline in SRT-delayed recall score; the adjusted scores lowered from -0.10 points [95% confidence interval (CI), -0.16 to -0.04) to -0.07 points (95% CI, -0.13 to -0.02). We observed that a higher nighttime BP variability during follow-up was associated with a decline in the MMSE score (adjusted score lowered from -0.08 to -0.06 points).

Higher 24-h BP variability, but not BP level, was associated with cognitive decline. Prior to or in the early stages of cognitive decline, 24-h ambulatory BP monitoring might guide strategies to reduce the risk of major dementia-related disorders including Alzheimer's disease.