Almost six million Americans are living with Alzheimer’s disease, including 200,000 people under the age of 65. It’s the most common cause of dementia and is the sixth-leading cause of death in the United States.
The study, published in the American Heart Association journal Hypertension, sought to find the connection between blood vessels and Alzheimer’s disease. There have been previous studies that showed how blood pressure variability could be connected to stroke, so researchers wanted to study a similar link between Alzheimer’s disease and fluctuating blood pressure.
“Everybody already knows that it’s important to control blood pressure in midlife to reduce your risk of Alzheimer’s later, but this tells us it’s still important to regulate blood pressure when you already have dementia,” said the study’s senior author, Dr. Jurgen Claassen. “More fluctuations might affect whether cognitive function declines more slowly or rapidly.”
For the study, researchers looked at data from a randomized trial of 460 people who had an average age of 72 years and had mild to moderate Alzheimer’s. It was found that after 1 ½ years, patients who showed the highest variability in blood pressure had more deterioration on a cognitive scale than those with the least amount of variability.
Unfortunately, data on day-to-day blood pressure variability was only available for 46 patients, but even in that small group, they found significant associations between dementia and fluctuating blood pressure. These associations were found after one year, but not after 1 ½ years.
A previous study from 2018 in the journal Neurology found the brains of older people with higher blood pressure were more likely to have “tangles,” or twisted strands of protein that are often common markers of Alzheimer’s. This study along with others are helping to map out the connections of blood pressure and dementia.
Future Research Needed
Because this study was so small, Claassen, associate professor at Radboud University Medical Center in Nijmegen, Netherlands, remarked that “future research is needed to find out if blood pressure variability is truly causing the dementia to worsen.”
“If that’s true, medication or lifestyle changes might help slow down disease progression,” he added. “But it could also be the other way around … that the dementia itself might lead to blood pressure variability, which could be a signal that helps you identify people with Alzheimer’s.”
“Alzheimer’s treatments are limited at this point, and even a small difference in slowing down the disease’s progression can mean a lot,” Claassen said. “It could be the difference between whether or not a patient is still able to drive a car and live independently.”
Even though this type of research is relatively new and has been limited by its small sample size, it does help to pave the way for future research. Claassen has called for more studies on how diet, sleep, and exercise might help to stabilize blood pressure. New studies also will also require patients to wear devices to track their day-to-day blood pressure variability.