Use of Antihypertensives, Blood Pressure, and Estimated Risk of Dementia in Late Life: An Individual Participant Data Meta-Analysis.
Level 3 - non-randomized controlled study
Individual participant data meta-analysis of non-randomized longitudinal cohort studies
PubMed 37698858 · doi:10.1001/jamanetworkopen.2023.33353
What was done
An individual participant data meta-analysis pooled 17 longitudinal, population-based cohort studies from 15 countries within the Cohort Studies of Memory in an International Consortium (COSMIC). The analysis included 34,519 dementia-free participants aged 60 to 110 years (mean age 72.5 years, 58.4% female, mean follow-up 4.3 years). Participants were categorized into healthy controls, treated hypertension, and untreated hypertension, with baseline systolic (SBP) and diastolic (DBP) blood pressure evaluated as continuous variables. Mixed-effects Cox proportional hazards models were adjusted for age, age squared, sex, education, racial group, and study-level random effects to evaluate risk of incident all-cause dementia.
What was found
Untreated hypertension was associated with a 42% higher risk of dementia compared with healthy controls (hazard ratio [HR], 1.42; 95% CI, 1.15-1.76; P = .001) and a 26% higher risk compared with treated hypertension (HR, 1.26; 95% CI, 1.03-1.53; P = .02). Treated hypertension was not significantly associated with increased dementia risk compared with healthy controls (HR, 1.13; 95% CI, 0.99-1.28; P = .07). Baseline continuous SBP and DBP showed no significant association with dementia risk, and associations did not differ significantly by age, sex, or racial group.
Why it matters
This study provides international, individual-level evidence that late-life antihypertensive treatment is associated with a reduction in dementia risk down to levels comparable to normotensive peers, independent of age, sex, or racial background.
Limits
The underlying cohort studies were observational, leaving potential for residual confounding and confounding by indication. The mean follow-up of 4.3 years is relatively brief for dementia progression and risks reverse causation. Blood pressure and medication use were assessed only at baseline, missing midlife blood pressure trajectories, longitudinal fluctuations, and changes in treatment adherence. The abstract does not report specific antihypertensive drug classes or dosages.
Cited by
- supports Studies show that administering antihypertensive medications has a positive impact on cognition.