Age- and Functional Status-Dependent Association Between Blood Pressure and Cognition: The Milan Geriatrics 75+ Cohort Study

Abstract

Objectives: To evaluate whether the relationship between blood pressure (BP) measures and cognitive function is different according to age and functional status in older outpatients.

Design: Cross-sectional.

Setting: Outpatient hospital-based Milan Geriatrics 75+ Cohort Study.

Participants: Individuals aged 75 and older (N = 1,540).

Measurements: Blood pressure, Mini-Mental State Examination (MMSE), basic activities of daily living (ADLs), and instrumental activities of daily living (IADLs) were assessed. Associations between BP measures and MMSE score were first analyzed in the total population using linear regression models and were then further examined according to strata of age, ADLs, and IADLs. All analyses were adjusted for sociodemographic factors and presence of comorbidities.

Results: In the total population, higher systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP) were all associated with higher MMSE score (all P < .05). Each 10-mmHg higher SBP and DBP was associated with a 0.26- and 0.55-point higher MMSE score, respectively. The associations between MMSE score and SBP, DBP, and MAP differed materially according to strata of age and functioning and were most pronounced in those aged 85 and older, with ADL impairments, and with IADL impairments.

Conclusion: Higher BP is associated with better cognitive function in the oldest old and in those with impaired functional status.

Keywords: aging; blood pressure; cognitive function; cohort study; functional status.