In the first update to U.S. guidelines on blood pressure in 14 years, a writing committee changed the definition of high blood pressure from 140/90 millimeters of mercury or higher to 130/80 or higher.
The lower threshold means an estimated 46 percent of U.S. adults have hypertension, up from 32 percent using the previous definition.
But the guidelines, which also provide recommendations for the detection, prevention and treatment of high blood pressure, suggest only a small increase in the number of adults who need antihypertensive medication. Lifestyle changes should be the first-line defense in most cases, they said.
“Nine out of every 10 times you see high blood pressure, it’s because the diet or the nutrition isn’t as good as it could be, it’s because we’re not as physically active as we could be and should be, and perhaps it’s because we’re consuming too much alcohol,” lead guidelines author Paul K. Whelton, MB, MD, MSc, said in a video released by the American Heart Association (AHA). “There’s a lot that we can do to prevent high blood pressure. And then if we haven’t, of course there’s a lot we can do with lifestyle approaches and, if it’s appropriate, drug therapy.”
The updated guidelines were presented at the AHA’s Scientific Sessions in Anaheim, California, on Nov. 13 and published by the AHA and the American College of Cardiology. Eleven organizations collaborated on the project and reviewed more than 900 published studies.
In addition to lowering the threshold for hypertension, the writing committee eliminated the category of prehypertension, which was defined as systolic blood pressure between 120-139 mm Hg or diastolic blood pressure between 80-89 mm Hg. The new categories are as follows:
- Normal: less than 120/80 mm Hg
- Elevated: systolic between 120-129 and diastolic less than 80
- Stage 1: systolic between 130-139 or diastolic between 80-89
- Stage 2: systolic of 140 or more or diastolic of at least 90
- Hypertensive crisis: Systolic over 180 or diastolic over 120, with patients either needing a prompt change in medication or immediate hospitalization if there are signs of organ damage
Regarding the move to a lower threshold for hypertension, Whelton pointed to the dangers of blood pressure levels between 130-139/80-89 mm Hg.
“You’ve already doubled your risk of cardiovascular complications compared to those with a normal level of blood pressure,” he said in a press release. “We want to be straight with people — if you already have a doubling of risk, you need to know about it. It doesn’t mean you need medication, but it’s a yellow light that you need to be lowering your blood pressure, mainly with non-drug approaches.”
The guidelines also identified socioeconomic and psychosocial stress as risk factors for hypertension that should be considered in patient care. They recommend prescribing medication for patients with Stage 1 hypertension only if they have had a previous heart attack or stroke, or have defined risk factors for heart attack or stroke.
Joaquin E. Cigarroa, MD, the head of the division of cardiovascular medicine at Oregon Health and Science University, said 70 percent of the people now recognized at increased risk can be treated with nutrition and lifestyle changes alone.
“There are three major things that I would say are in here: First, I think we now do a better job in the definition of high blood pressure,” Whelton said. “Secondly, we do a better job in targeting those who need lifestyle change on its own and those who need, in addition, drug therapy. And thirdly, we set lower blood pressure targets during treatment. If all those three things occur, adults in our population will benefit and as a society, we’ll benefit.”
Whelton pointed out it is preferable to prevent hypertension in the first place than to treat it. He said parents should set examples for their children on having a healthy diet, exercising regularly and consuming alcohol in moderation.