Normal Blood Pressure Readings May Still Hide a Serious Risk

Blood pressure is often judged by its average reading, but mounting evidence suggests that the ups and downs throughout the day may matter just as much. Sudden or large shifts in blood pressure can raise the risk of heart disease, stroke, and brain injury on their own, even when the overall average stays in the normal range.

Researchers at the University of Virginia School of Medicine have identified a small group of nerve cells in the brainstem that helps keep blood pressure steady. Because the brainstem controls vital involuntary functions, these cells appear to reduce blood pressure swings during routine changes such as sleeping, waking up, standing, and exercising.

"What we found is that a loss of just a few hundred nerve cells leads to unstable blood pressure even though the mean blood pressure was normal," said UVA's Stephen Abbott, PhD, the study's lead investigator. "This shows that the system that keeps blood pressure steady from moment to moment is no longer working."

A Brain-Based Explanation for Blood Pressure Instability

The same nerve cells were previously shown to be damaged or absent in people with multiple system atrophy, a rare and fatal neurological disease related to Parkinson's disease. That disorder is often marked by severe problems with blood pressure regulation.

The latest findings suggest that problems affecting these brain cells may also play a role in unstable blood pressure in other conditions, including situations where standard measurements still appear normal. If this mechanism is better understood, researchers may be able to develop treatments that limit harmful blood pressure fluctuations and reduce their effects.

"Our work emphasizes a new appreciation for how we think about blood pressure problems," Abbott said. "It's not just about lowering the numbers - it's about keeping blood pressure stable from moment to moment."

New Findings May Influence Future Treatment

The study was published in the journal Circulation Research. The research team included George M.P.R. Souza, Harsha Thakkalapally, Faye E. Berry, Leah F. Wisniewski, Ulrich M. Atongazi, Daniel S. Stornetta, and Abbott. The researchers reported no financial conflicts related to the work.

Funding came from the National Institutes of Health through grant HL148004.

The discovery also aligns with the broader mission of UVA's newly established Paul and Diane Manning Institute of Biotechnology, which aims to advance research on difficult diseases and help promising lab discoveries move more quickly toward possible treatments for patients.