UC Irvine-led study challenges traditional risk factors for brain health in the oldest-old

(Press-News.org) Irvine, Calif., Jan. 7, 2025 – A study led by the University of California, Irvine has found cardiovascular conditions such as high blood pressure and diabetes, which are known to contribute to brain blood vessel damage in younger populations, not to be associated with an increased risk of such harm in individuals 90 and older.

 

The work, published online today in the journal Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, suggests that the relationship among blood pressure, vascular health and brain aging is more complex than previously thought.

 

“For decades, we’ve known that factors like high blood pressure and diabetes can injure blood vessels in the brain, increasing the risk for cognitive decline and dementia. However, our research found that these patterns may change as people age,” said corresponding author Dr. Ravi Rajmohan, UC Irvine clinical instructor of neurology. “Even more intriguing, the use of blood pressure-lowering medication in this 90-plus group was linked to a lower likelihood of specific types of brain damage.”

 

Team members analyzed the relationship between cardiovascular-related changes in the brain and self-reported vascular risk factors or use of heart-related medications by examining data from 267 participants in the National Institute on Aging’s 90+ Study, one of the largest and most comprehensive research projects on the oldest-old population. They applied statistical models that accounted for age, sex and education and found that the presence of brain changes was not linked to traditional risk factors like high blood pressure or diabetes.

 

In addition, they discovered that certain medications showed potential proactive effects. Diuretics were linked to a lower likelihood of atherosclerosis, commonly called “hardening of the arteries,” and beta blockers and vasodilators were associated with reduced odds of cerebral amyloid angiopathy, the buildup of a type of proteins in brain blood vessels.

 

“Our findings challenge the idea that traditional vascular risk factors are always harmful to brain health in the 90-plus population,” Rajmohan said. “Our findings may reflect the effectiveness of treatment for those conditions, or they could be influenced by survival bias, as individuals with untreated or severe risk factors may not live into their 90s. Further research is needed to explore whether blood pressure-lowering medications could directly reduce the risk of brain blood vessel damage and dementia under specific circumstances. Such knowledge could lead to more personalized advice for managing blood pressure and improving brain health outcomes.”

 

Team members also included Dr. Claudia Kawas, professor of neurology and neurobiology & behavior; Maria Corrada, professor in residence of neurology; Annlia Paganini Hill, project scientist in neurology; and biochemistry graduate student Joey Wong – all from UC Irvine – as well as Dr. Thomas Montine, chair pathology at Stanford University; Zeinah Al-Darsani, epidemiology and biostatistics graduate student at Temple University’s College of Public Health; and Chu-Ching Ho, computer science graduate student at the University of Illinois Urbana-Champaign.

 

This work was supported by the National Institute on Aging under grant AG021055 and the Alzheimer’s Disease Research Consortium under grant P30AGO66519.

 

About the University of California, Irvine: Founded in 1965, UC Irvine is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UC Irvine has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UC Irvine, visit www.uci.edu.

 

Media access: Radio programs/stations may, for a fee, use an on-campus studio with a Comrex IP audio codec to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at https://news.uci.edu/media-resources.

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