New Blood Pressure Guidelines: Why Are Previously Normal BPs Now Classified as High Blood Pressure?

Under the new blood pressure guidelines, more people are classified as having high blood pressure; but the treatment emphasis is on lifestyle changes, not medications.

The American Heart Association and the American College of Cardiology recently released new guidelines for the diagnosis and treatment of high blood pressure. The highlights are reported here. Previously, high blood pressure (HBP) was classified as 140/90 mm Hg or above. Under the new guidelines, more people are now being diagnosed with HBP, not because their blood pressure has changed, but just because the definition has changed.

The new categories are (systolic BP in mm Hg and diastolic BP in mm Hg):

  • Normal: <120 and 80
  • Elevated: 120-129 and <80
  • Hypertension stage 1: 130-139 or 80-89
  • Hypertension stage 2: ≥140 or ≥90

But that doesn’t necessarily mean that all the newly diagnosed people are going to be treated with drugs. The guidelines include these recommendations for treatment or follow-up:

  • For normal BP: evaluate yearly, encourage healthy lifestyle changes.
  • For elevated BP: recommend healthy lifestyle changes and reassess in 3-6 months.
  • For hypertension stage 1: Assess 10-year risk of heart disease and stroke and…
    • If risk is <10%, start with healthy lifestyle recommendations and reassess in 3-6 months.
    • If risk is >10% or if the patient has known cardiovascular disease, diabetes, or chronic kidney disease, recommend lifestyle changes and prescribe one BP-lowering medication and reassess in a month and…
      • If BP has reached goal, reassess in 3-6 months.
      • If goal is not met, make changes to medication and follow monthly until BP is under control.
    • For hypertension stage 2: recommend healthy lifestyle changes and 2 BP medications of different classes; reassess in 1 month for effectiveness and…
      • If goal is met, reassess in 3-6 months.
      • If goal is not met, change meds and continue monthly follow-up until goal is met.

Alarmist headlines warn that nearly half of US adults will be classified with high blood pressure. The percentage of adults with high blood pressure was 32% under the old guidelines; now it is 46%. But note that healthy lifestyle changes are first and foremost for all categories. By one estimate, the new guidelines will increase the number of women on anti-hypertensive medications by only 1.3% and men by 2.5%.

The recommended lifestyle changes include a heart-healthy diet (such as the DASH diet, reduced salt, and potassium-rich foods like bananas, potatoes, avocados, and dark green leafy vegetables), weight loss, stopping cigarettes, cutting back on alcohol, and increasing physical activity. Specific suggestions are included. They also address ways to more accurately measure BP, screening for “white coat syndrome,” special provisions for people with various existing health conditions, and management of hypertensive crises.

The new guidelines are not a plot by Big Pharma to increase prescription drug sales, nor are they a conspiracy of doctors who want to get paid for more visits. They are a well-thought-out effort by experts to improve health outcomes for their patients. People with a systolic blood pressure of 130 have twice the risk of cardiovascular events as people with a blood pressure of 120. The committee that formulated the guidelines based them on an extensive systematic review of the published evidence, which experts interpreted as showing that lowering systolic BP to <130 could be expected to significantly reduce the risk of several outcomes including heart attack, stroke, heart failure, and major cardiovascular events.

Conclusion: Prevention before pills

I’m sure this will generate a lot of controversy, just as the new cholesterol guidelines did. A family doctor, Kenny Lin, has already spoken out on Medscape. He pointed out that there was only one primary care physician on the expert panel. He said:

Cardiologists have the luxury of only needing to be concerned with cardiovascular disease, but the vast majority of my patients with hypertension have comorbid chronic conditions and take several medications. Adding one more anti-hypertensive drug means more potential side effects, medication interactions, and costs to the patient and the health system.

In my opinion, the new guidelines are a welcome advance. They represent a carefully thought out consensus of a task force of experts based on the best available evidence, and following them should reduce the number of heart attacks and strokes. As with other guidelines, they are only meant as general guidelines for the population as a whole, and clinicians can and should modify them as needed for the individual patient, based on many other considerations including the ones Dr. Lin pointed out.

Critics of mainstream medicine like to say that doctors don’t care about prevention and they just automatically hand out pills. These new guidelines are evidence that doctors do care very much about prevention and they don’t just hand out pills.

Addendum: after I wrote this, the AAFP decided not to endorse the new guidelines, but to stick with the earlier recommendations from 2014.

This article was originally published in the Science-Based Medicine Blog.

Dr. Hall is a contributing editor to both Skeptic magazine and the Skeptical Inquirer. She is a weekly contributor to the Science-Based Medicine Blog and is one of its editors. She has also contributed to Quackwatch and to a number of other respected journals and publications. She is the author of Women Aren’t Supposed to Fly: The Memoirs of a Female Flight Surgeon and co-author of the textbook, Consumer Health: A Guide to Intelligent Decisions.