Gradual Blood Pressure Increase Might Signal Impending Hypertension.

Hypertension, or abnormally high blood pressure, is associated with an increased risk of heart attack and stroke. Yet many healthcare professionals still believe that incremental changes in blood pressure are normal, and expected, with aging.

Now, a new study co-authored by School of Public Health researchers found that a systolic blood pressure that regularly exceeds 120-125 mmHg could signal impending hypertension, regardless of age.

The study was published in JAMA Cardiology.

“There used to be a widespread belief that a gradual increase in blood pressure over time is part of normal aging,” says senior author Susan Cheng, cardiologist at Brigham and Women’s Hospital. “But, if you look at native communities, where people live without the lifestyle exposures usually seen in industrialized societies, this trend is hard to find.”

The researchers examined data from 1,252 participants from the Framingham Heart Study, which contains one of the few existing cohorts with standardized blood pressure measurements performed every two years over an extended period of time (1948 to 2005). The team defined hypertension onset as a blood pressure over or equal to 140/90 mmHg. Participants were categorized based on the age at which their hypertension was diagnosed.

Among the patients who developed hypertension, the researchers found that blood pressure trajectories leading up to the onset of hypertension appeared similar in pattern. In fact, blood pressure levels were generally stable until they approached the range of ~120–125 mmHg, above which their blood pressure rose rapidly and into the range of hypertension. Moreover, many people in the study were able maintain a systolic blood pressure below 120-125 mmHg and, in effect, delay the uptick of blood pressure elevation until much later in life—and in some cases, avoid it altogether.

The researchers suggested that further investigations are needed to unravel the sequence of changes in the body that occur before hypertension sets in and to determine the potential benefits of interventions in preventing progressive rises in blood pressure, at any age.

Co-authors from SPH were Martin G. Larson, research professor of biostatistics, and Vasan S. Ramachandran, professor of epidemiology. Co-authors from Brigham and Women’s Hospital were Mir Henglin, Brian Claggett, and Elizabeth McCabe. Other co-authors included:  Teemu J. Niiranen of the Framingham Heart Study; Vito M. Muggeo of the University of Palermok, and Mohit Jain, assistant professor at the University of California–San Diego.