July 17, 2018
New Blood Pressure Guidelines: The Numbers Game

New Blood Pressure Guidelines: The Numbers Game

by Berkeley Wellness  

In November, long-awaited revised guidelines about high blood pressure from the American College of Cardiology and American Heart Association (ACC/AHA) lowered the cutoffs defining hypertension and thus greatly expanded the number of Americans who officially have the condition—from 72 million under the old guidelines to 103 million now. That’s nearly half of all adults, including many under age 45, along with nearly 80 percent of those over 65. Two key changes are the elimination of the prehypertension category, half of which is now included under hypertension, and an increased emphasis on lifestyle changes as the cornerstone of treatment.

The new categories

  • Normal blood pressure remains less than 120/80 (that is, 120 systolic and 80 diastolic).
  • Elevated blood pressure, a new category: systolic 120 to 129 with normal diastolic (that is, less than 80). This was previously categorized as prehypertension.
  • Stage 1 hypertension: systolic 130 to 139 or diastolic 80 to 89. This was also previously included under prehypertension.
  • Stage 2 hypertension: systolic 140 or higher or diastolic 90 or higher. Previously this was stage 1 and became stage 2 starting at systolic 160 or diastolic 100.

One rationale for the changes is the fact that cardiovascular risk starts to rise steeply at lower levels than the previous cutoffs suggested. Heart attack and stroke risk doubles at 130/80, for instance, compared to below 120/80, according to the AHA. Plus, recent research has demonstrated that having people with hypertension aim lower than the old cutoff of 140/90 greatly reduces heart attacks, strokes, and premature death, with little increase in adverse effects (such as fainting) from more aggressive drug treatment. The new goal is less than 130/80.

Despite the fact that the new guidelines will classify 31 million more Americans as having hypertension, the ACC/AHA estimates that only 4 million of them are likely candidates for drugs to treat the disorder. That’s because people with stage 1 hypertension, like those with “elevated blood pressure,” are advised to focus on lifestyle changes such as losing excess weight, exercising more, quitting smoking, limiting alcohol, and improving their diet (notably by reducing sodium, increasing potassium, and following the DASH eating plan).

People with stage 1 hypertension are candidates for medication only if lifestyle modification doesn’t help enough and if they already have cardiovascular disease—or if they have a 10-year cardiovascular risk of at least 10 percent as evaluated by an online calculator. Since age is such a big factor in the calculator, nearly everyone over 65 will have a calculated risk that high. People with stage 2 hypertension are advised to take medication (usually two drugs from different classes), along with making lifestyle changes.

Keep in mind that only half of people currently treated for hypertension under the old guidelines have been able to get it under control via lifestyle or drugs. The new goals will be even more challenging to achieve. Undoubtedly, by aiming for the new lower goals, more people will at least achieve the old goals.

It’s vital for people to realize that high blood pressure poses great risks. There’s no one-size-fits-all treatment, so working with your health care provider is key. The UC Berkeley Wellness Letter and BerkeleyWellness.com will continue to provide practical guidance on how to keep blood pressure in the healthy range and get it under control if it is elevated, starting with High Blood Pressure: Your Questions Answered.

For perspective on the guidelines, see Dr. John Swartzberg's column Perspective on the New Blood Pressure Guidelines.

Also see How to Shake the Salt Habit.