A new study shows that higher long-term variability in blood pressure readings are linked to faster declines in brain and cognitive function among older adults.
“Blood pressure variability might signal blood flow instability, which could lead to the damage of the finer vessels of the body with changes in brain structure and function,” said Bo (Bonnie) Qin, Ph.D., lead study author and a postdoctoral scholar at Rutgers Cancer Institute in New Brunswick, New Jersey.
“These blood pressure fluctuations may indicate pathological processes such as inflammation and impaired function in the blood vessels themselves.”
For the study, researchers analyzed data from 976 Chinese adults who participated in the China Health and Nutrition Survey over a period of five years. Half of the study participants were women, while all were 55 years or older.
Blood pressure variability was calculated from three or four visits to a health professional. Participants also underwent a series of cognitive quizzes, such as performing word recall and counting backwards, the researchers explained.
According to the study’s findings:
- higher visit-to-visit variability in the top number in a blood pressure reading (systolic blood pressure) was associated with a faster decline of cognitive function and verbal memory;
- higher visit-to-visit variability in the bottom number (diastolic blood pressure) was associated with faster decline of cognitive function among adults ages 55 to 64, but not among those age 65 and older;
- neither average systolic or diastolic blood pressure readings were associated with brain function changes.
Qin said that while physicians tend to focus on average blood pressure readings, high variability may be something doctors should monitor as well.
“Controlling blood pressure instability could possibly be a potential strategy in preserving cognitive function among older adults,” she said.
The researchers note that the study was observational and does not suggest a direct cause and effect between blood pressure variability and brain function decline.
However, the findings add to a growing body of evidence that variations in blood pressure readings — perhaps more so than averages — may indicate an increased risk for some additional health problems, the researchers said.
Clinical intervention trials and longer term studies are needed to confirm the findings, the researchers added.
The study was published in the American Heart Association’s journal Hypertension.