Associations of blood pressure fluctuation patterns with cognitive function: the mediating role of cumulative blood pressure

The impact of different fluctuation patterns of blood pressure (BP) on episodic memory remains underexplored, and the role of cumulative BP in this association remains unclear. Using data from the China Health and Retirement Longitudinal Study, 6563 participants aged 45 years or more were analyzed. BP was measured in wave 1 (2011), wave 2 (2013), and wave 3 (2015). Cumulative systolic BP (SBP) during wave 1-3 (area under the curve) and the SBP difference between wave 1-2 and wave 2-3 were calculated. Then, SBP differences in the two intervals were used to identify patterns by K-means cluster analysis. Episodic memory, including immediate and delayed memory, was assessed in wave 4 (2018). Linear regression and mediation analysis were conducted, with multivariable adjustment. Three fluctuation patterns of SBP were identified, characterized as an increase-decrease (19.9%), decrease-increase (25.7%), and stable (54.4%) pattern. Before cumulative SBP adjustment, compared to the stable SBP pattern, the β (95% CIs) for episodic memory at wave 4 was -0.14 (-0.27, -0.01) for immediate memory, -0.12 (-0.31, 0.06) for delayed memory, and -0.27 (-0.57, 0.03) for total memory in the increase-decrease SBP pattern, and -0.06 (-0.18, 0.07), 0.01 (-0.15, 0.18), and -0.03 (-0.30, 0.25) in the decrease-increase SBP pattern. The overall association between the increase-decrease SBP pattern and immediate memory was partly mediated by cumulative SBP (29%). The increase-decrease pattern of SBP was associated with lower immediate memory three years later, and cumulative SBP partly mediated the association.