Background:
Abnormal 24-hour ambulatory blood pressure monitoring (ABPM) patterns have been associated with diminished cognitive function in hypertensive and very elderly populations. The relationship between ABPM patterns in community-living older adults is unknown.
Methods:
We conducted a cross-sectional study in which ABPM, in-clinic blood pressure, and cognitive function measures were obtained in 354 community living older adults. We used multiple linear regression to examine the associations of in-clinic and ABPM with the Montreal Cognitive Assessment (MoCA [range 0-30 with lower levels indicating worse cognition]), adjusting for age, sex, race/ethnicity, education, and comorbid medical conditions.
Results:
The mean age was 72 years, 68% were female, and 13% were African American; 45% had a diagnosis of hypertension. In-clinic blood pressure measurements were not significantly associated with cognitive function after adjustment. In contrast, less nighttime systolic dipping percentage (Figure) and lower 24-hour average diastolic blood pressure obtained from the ABPM were both significantly associated with worse cognitive function. In the final model, each 1% less night-time dipping was associated with 0.25 points (0.1-0.9) lower MoCA score, whereas each 10 mmHg lower diastolic blood pressure was associated with 0.59 (0.14-1.05) points lower MoCA score.
Conclusions:
In community-living older persons, less nighttime systolic dipping and lower 24-hour diastolic blood pressure obtained by ABPM were associated with worse cognitive function whereas clinic based blood pressure measurements were not. Future studies should examine whether 24-hour diastolic blood pressure and nighttime systolic dipping may predict future risk for cognitive impairment.
(Legend: Dipping quartiles: Q1 -17.8% to 6.0%; Q2 6.1% to 11.0%; Q3 11.1% to 16.3%; Q4 16.4% to 34.2%)