Antihypertensive Treatment Throughout Late Life May Reduce Risk of Dementia

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Antihypertensive therapy in late life can be a key part of dementia prevention, according to new research published in JAMA Network Open.

Findings from the meta-analysis of individual participant data from approximately 34 000 older adults in 17 studies showed that untreated hypertension (HTN) was associated with a higher risk of dementia compared with treated HTN. This association was not modified by age, added researchers.

“Antihypertensive use was associated with decreased dementia risk in late-life individuals with hypertension; thus, dementia risk reduction may be 1 of the multiple goals of antihypertensive treatment in late-life (eg, prevention of ischemic heart disease, chronic kidney disease),” wrote first author Mathew Lennon, MD, Centre for Healthy Brain Aging, University of New South Wales, Sydney, Australia, and colleagues.

Lennon and coauthors conducted the current study to analyze to associations of HTN history, use of antihypertensive treatments, and baseline measured blood pressure (BP) in late life (ie, aged >60 years) with dementia “and the moderating factors of age, sex,and racial group.”

Investigators included longitudinal, population-based studies of aging participating in the Cohort Studies of Memory in an International Consortium group, according to the study. Participants included persons without a dementia diagnosis at baseline, aged 60-110 years, and based in 15 different countries, including US, Brazil, Australia, China, Korea, France, and Greece.

Researchers grouped participants into 3 categories based on previous HTN diagnosis and baseline antihypertensive use:

• Healthy controls
• Treated HTN
• Untreated HTN

Baseline systolic BP (SBP) and diastolic BP (DBP) were treated as continuous variables, according to the study. The key outcome was all-cause dementia, and study authors used mixed-effects Cox proportional hazards models to examine the associations between the exposures and all-cause dementia.

“The main analysis was a partially adjusted Cox proportional hazards model controlling for age, age squared, sex, education, racial group, and a random effect for study,” wrote Lennon and colleagues. “Sensitivity analyses included a fully adjusted analysis, a restricted analysis of those individuals with more than 5 years of follow-up data, and models examining the moderating factors of age, sex, and racial group.”

FINDINGS

A total of 17 studies with 34 519 community-dwelling older adults (58.4% women; mean age, 72.5 years) and a mean follow-up of 4.3 years were included in the analysis.

Results from the main, partially adjusted analysis consisting of 14 studies showed that participants with untreated HTN had a 42% increased risk of dementia compared with healthy controls (hazard ratio [HR] 1.42, 95% CI 1.15-1.76; P=.001) and 26% increased risk compared with those with treated HTN (HR 1.26, 95% CI 1.03-1.53; P=.02).

In addition, there was no significant difference in dementia risk in participants with treated HTN compared with healthy controls (HR 1.13, 95% CI 0.99-1.28; P=.07), according to researchers.

“In the fully adjusted analysis including 9 studies, these results were replicated with similar effect sizes, but in the analysis restricted to participants with more than 5 years of follow-up (10 studies), the findings were no longer significant,” wrote Lennon et al.

Investigators also found that the association of antihypertensive use or HTN status with dementia did not vary with baseline BP. Furthermore, they did not observe a significant association of baseline SBP or DBP with dementia risk in any of the analyses.

“There were no significant interactions with age, sex, or racial group for any of the analyses,” added researchers.

The primary limitation to the current study was the variability in the cohort study design, according to authors.

Source: Lennon MJ, Lam BCP, Lipnicki DM, et al. Use of antihypertensives, blood pressure, and estimated risk of dementia in late life: An individual participant data meta-analysis. JAMA Netw Open. Published online September 12, 2023. doi:10.1001/jamanetworkopen.2023.33353