New study in JAMA Cardiology argues blood pressure is meant to remain stable with age
Traditional medical wisdom on hypertension has always been that incremental changes are normal with age.
However a new study by investigators at Brigham and Women’s Hospital, published in the journal of JAMA Cardiology, found that a systolic blood pressure that regularly exceeds 120-125 mmHg could signal impending hypertension, regardless of age. Systolic blood pressure is the upper reading that records the pressure in the heart when it is in a state of contraction.
Some estimates suggest that a quarter or urban Indians and 10% rural Indians are hypertensive.
These results are in line with the recently updated American College of Cardiology and American Heart Association high blood pressure guidelines, which categorize high blood pressure as greater than 130/80 mmHg. The findings are significant for India because it has a very high burden of hypertension. Some estimates suggest that a quarter or urban Indians and 10% rural Indians are hypertensive.
“There used to be a widespread belief that a gradual increase in blood pressure over time is part of normal aging,” says Susan Cheng, a cardiologist at BWH and senior author on the paper. “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. And so, we wondered if blood pressure is supposed to very gradually increase over time or instead remain stable. We also wanted to find out, for people in whom blood pressure does rise, is there a tipping point at which hypertension starts to develop. In other words, if hypertension does develop, when does the change start to happen, what does it look like, and how might we prevent it?”
In the study, researchers examined data from 1,252 participants from the Framingham Heart Study, which contains one of the few existing cohorts with standardized blood pressure (BP) measurements performed at frequent intervals (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 (age 40-49, 50-59, 60-69, 70-79 years, or no onset).
The research team found that, among the patients who developed hypertension, blood pressure trajectories leading up to the onset of hypertension appeared similar in pattern. In fact, their 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.
This finding was consistent whether the hypertension developed in middle or older age, suggesting that blood pressures above this level could represent a critical threshold of vascular remodeling occurring in the body. Interestingly, this blood pressure range is in line with recently published guidelines that lowered the definition of high systolic blood pressure to 130 mmHg.
