Fluctuating blood pressure can increase the risk of dementia and vascular problems in older people. Both short fluctuations in blood pressure within 24 hours and fluctuations in blood pressure over several days or weeks are associated with cognitive impairment.
A recent study involving researchers from the University of South Australia (UniSA) examined how blood pressure variability, cognitive function and vascular stiffness are linked to find out what role blood pressure variability plays in cognitive impairment.
How are fluctuations in blood pressure linked to dementia?
To understand the mechanisms underlying the connection between blood pressure fluctuations and dementia, the team examined a total of 70 healthy people aged 60 to 80. The results are published in the English-language journal “Cerebral Circulation – Cognition and Behavior”.
All participants showed no signs of dementia or cognitive impairment and their blood pressure was recorded in a 24-hour measurement as well as in morning and evening measurements over a period of four days, the researchers report.
In addition, arterial stiffness was measured using so-called transcranial Doppler sonography and pulse wave analysis, and the participants completed a cognitive test, the research team continued.
Lower cognitive performance due to fluctuations in blood pressure
“We found that higher fluctuations in blood pressure within a day and across days were associated with lower cognitive performance. We also found that higher blood pressure fluctuations within systolic blood pressure were associated with higher blood vessel stiffness in the arteries,” reports study author Daria Gutteridge in a press release.
Such stiffening of the arteries is in turn associated with an increased risk of heart disease.
According to the team, the results suggest that the different types of blood pressure fluctuations likely reflect different underlying biological mechanisms, and both systolic and diastolic blood pressure fluctuations play a significant role in cognitive performance in older individuals.
Blood pressure variability as a treatment goal
Since these associations are also observed in older adults without clinically significant cognitive impairment, this suggests that blood pressure variability could potentially serve as an early clinical marker or treatment target for cognitive impairment, the experts add.
According to Gutteridge, high blood pressure is a known risk factor for dementia, but little attention has been paid to fluctuating blood pressure in relation to cognition.
“Clinical treatments focus on hypertension but ignore blood pressure variability. Blood pressure can fluctuate over different periods of time – short and long – and this appears to increase the risk of dementia and blood vessel health,” concludes Gutteridge. (as)