The new normal: Changes to blood pressure guidelines you should know
2003 Adult Blood Pressure Classification:
Stage 1 hypertension 140-159/90-99
Stage 2 hypertension >160/100
2017 Adult Blood Pressure Classification:
Stage 1 hypertension 130-139/80-89
Stage 2 hypertension >140/>90
Hypertensive Crisis >180/>120
In 2016, about 75 million Americans — representing a whopping 29 percent of the adult population — had high blood pressure. And of those 75 million Americans, only 54 percent had their high blood pressure under adequate control.
These statistics from the Centers for Disease Control and Prevention relied on a definition of high blood pressure that was based on a comprehensive set of guidelines developed in 2003 by a Joint National Committee with the approval of the National Institutes of Health (NIH). Just a few months ago, in November 2017, radical changes were made to the guidelines used for diagnosing and treating hypertension (abnormally high blood pressure).
With American Heart Month having just concluded, it’s worth exploring these new guidelines and what they mean for the number of Americans suffering high blood pressure.
The new guidelines were published in a comprehensive report by the American College of Cardiology and the American Heart Association.
Nine other professional medical organizations took part in producing this major document, which relied on more than 900 medical studies. One in particular, called SPRINT (Systolic Blood Pressure Intervention Trial), was published in 2015.
This NIH study included almost 10,000 people with a systolic pressure of over 130. Note that systolic pressure is the first of the two numbers that comprise a blood pressure reading. These SPRINT study participants were randomly assigned to one of two groups.
The intensive treatment group had their systolic pressure lowered with a goal of less than 120. The other group had their systolic pressure lowered with a goal of less than 140. The intensive treatment group was found to have a reduced risk for heart attacks, strokes, heart failure and death. The benefits were so striking that the study was stopped early.
We know that blood pressure can vary moment to moment. A wide variety of stimuli, even just walking into a medical exam room, can raise the pressure. So when should blood pressure be measured to determine if someone has hypertension? In SPRINT, the investigators used an interesting technique for blood pressure measurement in an attempt to minimize outside stimuli.
After a study participant walked into an exam room, a high-quality automated blood pressure cuff was set up and programmed to measure the blood pressure once every minute for three readings, starting five minutes after medical personnel left the room.
The blood pressure reading obtained in this fashion may be lower than a blood pressure obtained during a usual medical office visit. As in SPRINT, medical providers should try and obtain blood pressure readings that are not influenced by outside stimuli before deciding if someone has hypertension.
Other ways this can be done include home blood pressure measurements, a 24-hour blood pressure monitor, waiting at least five minutes after the patient enters the exam room before measuring blood pressure, and taking several blood pressure measurements during the office visit.
With these new guidelines, the number of adults in the United States considered to have hypertension increases by 31 million to 46 percent of the population. However, the need for blood pressure-lowering medicine will apply to just 4 million of these people.
The rest of the newly diagnosed individuals who have a lesser elevation of blood pressure may need only to modify their lifestyle (a healthier diet and increased physical activity, for example) to achieve a normal blood pressure. For those already taking blood pressure-lowering medicine, 53 percent will need more medicine for improved blood pressure control.
The new recommendations also point out that those people who already have cardiovascular disease, or have a high risk of developing it, should have high blood pressure treated more aggressively.
It was not until the 1960s that the association between hypertension and cardiovascular disease was discovered. In the little more than 50 years since, much of the improvement in cardiovascular health can be attributed to an improvement in blood pressure control.
Now, with these new, more rigorous guidelines, cardiovascular health is expected to improve even more. If you are concerned that your blood pressure may be too high, please consult your doctor.
Dr. Peter Lemis is a board-certified cardiologist at Summit Cardiology in Frisco.
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