Higher fluctuations in blood pressure readings were linked to faster declines in brain and cognitive function among older adults, according to a new study published in the American Heart Association journal Hypertension.

“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 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.”

Researchers calculated blood pressure variability of 976 adults in the China Health and Nutrition Survey from three or four visits to health professionals over five years. Participants also took cognitive quizzes such as performing word recall and counting backwards.

Researchers found:

  • 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 55-64, but not among those 65 and older.
  • Neither average systolic or diastolic blood pressure readings were associated with brain function changes.

Physicians, who tend to focus on average blood pressure readings, should watch for patients’ high variability, Qin said.

“Controlling blood pressure instability could possibly be a potential strategy in preserving cognitive function among older adults,” she said.

The findings add to a growing body of evidence that variation in blood pressure — perhaps more so than averages — may increase risk for additional health problems. Clinical intervention trials and long-term studies are needed to confirm the findings.