Research from the University of Southern California has revealed that fluctuations in blood pressure between heartbeats may significantly impact brain health in older adults. The study indicates that even individuals with controlled blood pressure are at risk of cognitive decline if these fluctuations are excessive.
The study involved 105 adults, aged between 55 and 89, who underwent continuous blood pressure measurements while receiving brain scans. The findings showed that older adults exhibiting greater beat-to-beat changes in blood pressure had smaller brain volumes in regions crucial for memory, as well as elevated levels of neurofilament light, a protein associated with nerve-cell injury.
Link Between Blood Pressure Variability and Brain Health
Professor Daniel Nation, senior author of the study, explained that “blood pressure isn’t static; it’s always adapting to the body’s needs.” He noted that as people age, this regulation can become less effective. The research specifically measured the stiffness of arteries and the extent of blood pressure variations between heartbeats. Results indicated that even when the average blood pressure readings appeared healthy, significant fluctuations combined with arterial stiffness were associated with telltale signs of brain aging.
The study identified that participants with erratic blood pressure readings had smaller volumes in the hippocampus and the entorhinal cortex, areas of the brain that are often affected early in Alzheimer’s disease. This correlation persisted even after adjusting for factors such as age, sex, and average blood pressure, highlighting the potential importance of blood pressure variability as a risk factor for cognitive decline.
Implications for Future Research and Treatments
Published online in the Journal of Alzheimer’s Disease on October 17, 2023, these findings challenge the long-held notion that maintaining a stable average blood pressure is sufficient for brain health. Professor Nation emphasized the unexpected nature of these results, noting that rapid fluctuations in blood pressure were linked to brain injury, regardless of whether participants had hypertension or were on medication to manage their blood pressure.
This research suggests that individuals could have seemingly “normal” blood pressure in clinical settings while still experiencing harmful spikes and drops that stress the brain’s blood vessels. Over time, such instability could contribute to memory decline and neurodegeneration.
While the study does not establish causation, it underscores the necessity for further investigation into how blood pressure variations evolve over time and their potential predictive value regarding brain health. The researchers advocate for more targeted therapies to address these fluctuations, as existing treatments primarily focus on lowering average blood pressure.
Professor Nation concluded by highlighting the importance of monitoring blood pressure and following prescribed medications to mitigate risks associated with cognitive decline. “Development of therapies to address rapid blood pressure fluctuations should be a priority,” he stated, as these fluctuations may not be adequately managed by current medical approaches.
The findings from this study contribute to an emerging understanding of the intricate relationship between cardiovascular health and cognitive function, emphasizing the need for a holistic approach to brain health in aging populations.
