Blood pressure variability, dementia, and role of antihypertensive medications in older adults

Abstract

Introduction: We assessed the association between visit-to-visit blood pressure variability (BPV) up to 12 years and subsequent dementia risk, and tested the modifying effect of antihypertensive medications.

Methods: We studied 2234 participants from two community-based cohorts of older adults with normal cognition or mild cognitive impairment. Participants were followed through annual assessments for up to 27 years. Visit-to-visit BPV was quantified over 3, 6, 9, and 12 years, respectively.

Results: Higher systolic BPV (SBPV) during 3, 6, 9, and 12 years was associated with a subsequent increased risk of dementia, with hazard ratios ranging from 1.02 (95% confidence interval [CI]: 1.01-1.04) to 1.10 (95% CI: 1.05-1.16). The association between SBPV and dementia risk was stronger among participants not taking calcium channel blockers (p-for interaction < 0.05).

Discussion: Among older adults, long-term exposure to higher visit-to-visit SBPV is associated with an increased risk of dementia later in life, and calcium channel blockers may modify this association.

Highlights: Among adults aged >65, higher systolic blood pressure variability spanning 3-12 years is associated with an increased risk of dementia later in life. Single blood pressure measurement or mean blood pressure levels does not seem to associate with dementia risk among older adults. The association between systolic blood pressure variability and dementia risk is stronger among those not taking calcium channel blocker medications.

Keywords: antihypertensive medication; blood pressure variability; calcium channel blockers; dementia; older adults.

Figure 1.. Schematic diagram of study design.

The ROS cohort began recruitment in 1994 and the MAP cohort began recruitment in 1997. In 2021, participants had up to 27 and 21 years of follow-ups, respectively. Given the cohorts had similar study designs, data collection and recruitment strategies, they were merged into the ROSMAP cohort with up to 27 years follow-up. BPV was computed over the first 3, 6, 9 and 12 years. Incident dementia occurred after visit 2, 5, 8 and 11 corresponding to BPV periods, and dementia cases during the first 3, 6, 9 and 12 years were censored in each period-specific analyses, respectively.

Figure 2.. Kaplan-Meier plots for incident all-cause dementia risk according to blood pressure variability categories.

Abbreviations: SBPV: systolic blood pressure variability; DBPV: diastolic blood pressure variability.

Figure 3.. Systolic blood pressure variability and dementia risk according to antihypertensive medication classes.

Hazard ratios were calculated using continuous values of systolic blood pressure variability. All analyses were adjusted for age at baseline, years of education at baseline, sex, race, and history of vascular risk factors burden (smoking, hypertension and diabetes mellitus), vascular diseases burden (stroke, heart disease and claudication), medication use (cardiac, lipid lowering, and mental health medications) and mean SBP until the corresponding SBPV period. SBPV was assessed using coefficient of variance. *indicates p for interaction <0.05.