Visit-to-visit blood pressure variations: new independent determinants for cognitive function in the elderly at high risk of cardiovascular disease.
ABSTRACT Recently, visit-to-visit blood pressure (BP) variability has been shown to be associated with silent cerebral injury and stroke. However, the relationships between visit-to-visit BP variation and cognitive function are not clear.
The cognitive function was evaluated using a mini-mental state examination (MMSE) and global deterioration scale (GDS) in 201 elderly patients at high risk of cardiovascular disease (CVD) (79.9 ± 6.4 years old; women 75%). Based on 12 visits (once a month), visit-to-visit BP variability (expressed as the SD and coefficient of variation), maximum BP, minimum BP, and δ (maximum - minimum) BP were measured.
The MMSE score had significant negative correlations with coefficient of variation and δ in SBP, and δDBP. The GDS score had significant positive correlations with coefficient of variation and δ in SBP, and δDBP. Low MMSE score (<24) had significant positive correlations with coefficient of variation and δ in SBP, and δDBP. High GDS score (>3) had significant positive correlations with coefficient of variation and δ in SBP, and δDBP. In a multiple linear regression analysis adjusted for confounders, coefficient of variation (P < 0.001) and δ (P < 0.001) in SBP had significant negative associations with the MMSE score. The δSBP (P < 0.05) had significant positive association with the GDS score. The coefficient of variation and δ in SBP had significant positive associations with low MMSE score (P < 0.01, P < 0.01, respectively) and high GDS score (P < 0.05, P < 0.001, respectively).
In the high-risk elderly, exaggerated visit-to-visit BP fluctuations were significant indicators for cognitive impairment.