Relationship Between Blood Pressure Variability and Cognitive Function in Elderly Patients With Good Blood Pressure Control

Abstract

Background: Although higher blood pressure (BP) levels and BP variability have been associated with cognitive impairment, data are sparse regarding the relationship between BP variability and cognitive function in elderly patients with well BP control. Methods: We analyzed 232 ambulatory patients with one or more cardiovascular risk factors. All patients underwent ambulatory BP monitoring and the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Results: The mean age was 77.7 ± 8.3 years; 33.6% were male, and 85.3% were taking antihypertensive drugs. The average 24-hour BP level was 118.7 ± 10.0/68.3 ± 6.4 mm Hg. When we divided the weighted SD of systolic BP (SBP) as a measure of BP variability into quartiles, the top quartile group (≥19.6 mm Hg) had a significantly lower total MoCA-J score (15.4 [95% confidence interval 14.2-16.7] vs. 17.9 [17.2-18.6], P = 0.001) and lower scores on several domains, visuoexecutive (2.2 [1.9-2.6] vs. 2.8 [2.6-2.9], P = 0.012), abstraction (1.0 [0.7-1.2] vs. 1.3 [1.1-1.4], P = 0.015), attention (2.8 [2.4-3.1] vs. 3.6 [3.4-3.8], P = 0.001), and naming (2.1 [1.9-2.3] vs. 2.5 [2.4-2.6], P = 0.001) than quartiles 1 through 3 combined, after adjustment for age and 24-hour SBP. These associations were not found in the quartiles of 24-hour SBP. Conclusions: In elderly patients with well ambulatory BP control, higher BP variability but not average ambulatory BP level was associated with cognitive impairment.