Alzheimer’s risk altered by late-life high BP, antihypertensive treatment
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Key takeaways:
- Antihypertensive treatment in later life may prevent Alzheimer’s disease.
- All-cause dementia risk was elevated in the presence of high BP and not significantly affected by treatment.
Treating high blood pressure later in life may mitigate risk for developing Alzheimer’s disease among older individuals, according to a meta-analysis published in Neurology.
Risk for all-cause dementia without Alzheimer’s disease was also elevated with the presence of hypertension; however, treatment did not significantly mitigate risk, researchers reported.
“High blood pressure is a leading cause of stroke and cerebrovascular disease, and yet it can be controlled with medication, reducing a person’s risk of these diseases,” Matthew J. Lennon, MD, PhD, conjoint lecturer in the School of Clinical Medicine at the University of New South Wales in Sydney, said in a press release. “Taking blood pressure medications has also been found in previous research to reduce a person’s risk of dementias overall, but less is known about how blood pressure affects a person’s risk of Alzheimer’s disease. Our meta-analysis looked at older people and found that not treating blood pressure may indeed increase a person’s risk.”
BP, antihypertensive treatment and Alzheimer’s disease
The present meta-analysis included participant data from 31,250 participants (mean baseline age, 72 years; 41% men) from 14 community-based longitudinal studies on aging from the COSMIC group, which was designed to examine cognitive change and dementia diagnosis over time. All participating studies included data regarding basic demographics, Alzheimer’s disease diagnosis and BP history.
The main outcomes of interest included risk for developing Alzheimer’s disease and non- Alzheimer’s dementia — defined as diagnosis of all-cause dementia and not Alzheimer’s disease.
After adjusting for factors such as age, sex, education, race/ethnicity and study cohort, researchers reported that people with untreated hypertension experienced a 36% greater risk for Alzheimer’s disease compared with “healthy controls” — those with no history of hypertension and not taking antihypertensives (HR = 1.36; 95% CI, 1.01-1.83; P = .0406).
The risk for Alzheimer’s disease was also 42% greater in people with untreated compared with treated hypertension (HR = 1.42; 95% CI, 1.08-1.87; P = .0135).
In addition, individuals with treated hypertension (HR = 1.29; 95% CI, 1.03-1.6; P = .0267) and untreated hypertension (HR = 1.69; 95% CI, 1.19-2.4; P = .0032) had greater risk for non-Alzheimer’s dementia compared with healthy controls, but the difference between treated and untreated hypertension groups was not significant.
“Our meta-analysis that included people from around the world found that taking blood pressure medications was associated with decreased risk of Alzheimer’s disease throughout later life,” Lennon said in the release. “These results suggest that treating high blood pressure as a person ages continues to be a crucial factor in reducing their risk of Alzheimer’s disease.”
Relationship between BP and dementia ‘complicated’
In a related editorial, Sevil Yasar, MD, PhD, associate professor of medicine in neurology and geriatric medicine at Johns Hopkins Medicine, and Behnam Sabayan, MD, PhD, neurologist at Hennepin Healthcare Research Institute and assistant professor at the University of Minnesota School of Public Health, discussed how these findings underpin the complexity the relationship between BP and dementia.
“Individual participant data meta-analyses provide valuable resources to test hypotheses using large-scale and diverse data, but these features come with the caveat of significant heterogeneity. A focus on chronological age (vs. biological age) in this and previous studies presents a challenge in interpreting the available evidence on the link between hypertension and dementia risk in old age. Older individuals carry a broad spectrum of vascular risk factors, comorbidities and established cerebrovascular damage,” Yasar and Sabayan wrote. “Lennon et al used baseline BP as the risk factor for their outcomes, which is commonly performed, but this limits the conclusions that can be drawn because BP varies whether it is treated or not.
“There is also information that pulse pressure and/or BP variability are sensitive in predicting dementia risk; thus, future studies should explore these BP modalities,” they wrote. “The relationship between hypertension and dementia risk in old age is complicated. This complexity reminds us that the ‘one-size-fits-all’ approach in medicine cannot always address multifaceted issues and tends to overlook the unique nuances of every person’s condition and needs.”
References:
- Do people with high blood pressure have a higher risk of Alzheimer’s disease? https://www.eurekalert.org/news-releases/1054106. Published Aug. 14, 2024. Accessed Aug. 14, 2024.
- Yasar S, et al. Neurology. 2024;doi:10.1212/WNL.0000000000209788.
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