Further evidence that controlling high blood pressure can reduce dementia, Alzheimer's risk
Treating high blood pressure with medication not only improves older adults’ cardiovascular health, but also can reduce their risk of dementia and Alzheimer’s disease, according to a thorough examination of long-term data from four countries.
A global team of scientists cross-referenced data from six large, longitudinal studies that tracked the health of over 31,000 adults over age 55 across several years of follow-up. They found that treating high blood pressure — no matter with which type of antihypertensive drug — reduced dementia risk by 12% and the risk of developing Alzheimer’s disease by 16%. The findings, coordinated by investigators in the Laboratory of Epidemiology and Population Science of the NIA Intramural Research Program, were published in Lancet Neurology.
This comprehensive look extends the evidence from the recent SPRINT MIND trial that showed lowering blood pressure levels reduced the risk for a combination of dementia and mild cognitive impairment. The scientists teamed up to analyze data from six comprehensive, community-based health studies conducted between 1987 and 2008 in the United States, France, Iceland and the Netherlands. They examined all five major types of blood pressure medications — ACE inhibitors, angiotensin II receptor blockers, beta-blockers, calcium channel blockers and diuretics — and found that the type of medication did not make a difference.
Participant data was divided into two groups — 15,537 people with high blood pressure and 15,553 people with normal blood pressure. In all, 1,741 diagnoses of Alzheimer’s disease and 3,728 cases of other dementias developed over time. People who controlled their blood pressure with medicine were found to have the same risk for developing dementia as individuals with normal blood pressure who did not require medication.
The investigators were pleased to work with a deeper data pool than previous studies, allowing them to look at specific medication types used to keep blood pressure at safe levels. The expanded study also gave them much longer-term follow-up data, which were helpful to observe the gradual onset of dementia and Alzheimer’s symptoms. The large group of people studied also factored in additional health conditions common to older adults, giving them a clearer picture of the multiple issues that come with aging that are typically seen by general physicians.
Still to be investigated is how long-term changes in blood pressure impacts dementia risk, and further research with more detailed information is needed on specific antihypertensive medications.
Together with the SPRINT MIND trial, this latest data adds to the evidence base that treating and reducing high blood pressure can also help reduce the risk of dementia. The researchers hope their findings add urgency to the need for better hypertension awareness among the rapidly growing global population of older adults, many of whom are at risk for developing high blood pressure or already have it but are not managing it properly.
This study was supported by the Alzheimer’s Drug Discovery Foundation and the NIA Intramural Research Program.
These activities relate to NIA’s AD+ADRD Research Implementation Milestone 1.F, "Enable precision medicine research by supporting deep and longitudinal molecular endophenotyping of existing and new at-risk cohorts as well cohorts and/or individuals who resist disease despite high genetic risk."
Reference: Ding J, et al. Antihypertensive medications and risk for incident dementia and Alzheimer's disease: a meta-analysis of individual participant data from prospective cohort studies. Lancet Neurology. 2019;pii: S1474-4422(19)30393-X. doi: 10.1016/S1474-4422(19)30393-X.