ADELAIDE, Australia — It’s no secret that hypertension, or high blood pressure, can put someone at an increased risk of various cardiac issues, such as a heart attack or stroke. Now, however, research out of Australia finds that fluctuating blood pressure readings may increase the risk of dementia and vascular issues among older individuals.
Short blood pressure fluctuations within the span of 24 hours, as well as spread out over the course of several days or weeks, show a connection with impaired cognition, according to scientists from the University of South Australia. Higher systolic BP variations, which refer to the top number measuring pressure in arteries when a heart beats, also show an association with the stiffening of arteries – considered a hallmark of heart disease.
Lead study author Daria Gutteridge, a PhD candidate based in UniSA’s Cognitive Aging and Impairment Neuroscience Laboratory (CAIN), explains that while it’s common knowledge that high blood pressure is a risk factor for dementia, far less attention is paid to fluctuating blood pressure.
“Clinical treatments focus on hypertension, while ignoring the variability of blood pressure,” Gutteridge says in a media release. “Blood pressure can fluctuate across different time frames – short and long – and this appears to heighten the risk of dementia and blood vessel health.”
In an effort to explore the mechanisms underlying the link between blood pressure fluctuations and dementia, the research team recruited a group of 70 healthy older adults. All participants were between 60 and 80 years-old and showed no signs of dementia or cognitive impairment.
Everyone’s blood pressure was monitored, cognitive tests were administered, and arterial stiffness in the brain and arteries was measured using a combination of transcranial doppler sonography and pulse wave analysis.
“We found that higher blood pressure variability within a day, as well as across days, was linked with reduced cognitive performance. We also found that higher blood pressure variations within the systolic BP were linked with higher blood vessel stiffness in the arteries,” Gutteridge concludes.
“These results indicate that the different types of BP variability likely reflect different underlying biological mechanisms, and that systolic and diastolic blood pressure variation are both important for cognitive functioning in older adults.”
The links were present among older individuals with no clinically relevant cognitive impairment. This suggests BP variability may one day serve as an early clinical marker or treatment target for cognitive impairment, researchers add.
The study is published in the journal Cerebral Circulation – Cognition and Behavior.