A panel of physicians and experts commissioned to update the decade-old guidelines on hypertension has suggest that people over 60 can have a higher blood pressure than previously recommended before starting treatment control it.
The advice to change treatment goals that have been in place for more than 30 years wasn't passed without ruffling some feathers within the traditionally conservative Hippocratic community.
Until now, people were told to strive for blood pressures below 140/90, with some taking multiple drugs to achieve that goal. But the guidelines committee, which spent five years reviewing evidence, concluded that the goal for people over 60 should be a systolic pressure of less than 150. And the diastolic goal should remain less than 90.
Systolic blood pressure, the top number, indicates the pressure on blood vessels when the heart contracts. Diastolic, the bottom number, refers to pressure on blood vessels when the heart relaxes between beats.
Essentially, the committee determined that there was not strong evidence for the blood pressure targets that had been guiding treatment, and that there were risks associated with the medications used to bring pressures down.
The committee, composed of 17 academics, was tasked with updating guidelines last re-examined a decade ago. Their report was published online on Wednesday in The Journal of the American Medical Association.
Hypertension experts said they did not have a precise figure on how many Americans would be affected by the new guidelines. But Dr. William B. White, the president of the American Society of Hypertension, said it was "a huge number for sure." He estimated that millions of people over 60 had blood pressures between 140 and 150. Dr. Paul A. James, the chairman of the department of family medicine at the University of Iowa and co-chairman of the guidelines committee, said, "If you get patients' blood pressure below 150, I believe you are doing as well as can be done based on scientific evidence."
The group added that people over 60 who are taking drugs and have lowered their blood pressure to below 150 can continue taking the medications if they are not experiencing side effects.
But, it cautioned, although efforts to lower blood pressure have had a remarkable effect, reducing the incidence of strokes and heart disease, there is a difference between lowering blood pressure with drugs and having lower pressure naturally.
Medications that lower blood pressure can have effects that counteract some of the benefits, said Dr. Suzanne Oparil, a co-chairwoman of the committee and director of the vascular biology and hypertension program at the University of Alabama at Birmingham School of Medicine. For that reason, maximum benefits may occur with less intense treatment and higher blood pressure.
"The mantra of blood pressure experts in the past has been that lower is better," Dr. Oparil said. "Recent studies don't seem to support that."
For example, two Japanese studies in older people found that those who reduced their systolic pressure to less than 140 fared no better than those who reduced it to between 140 and 160, or between 140 and 149.
"We have this notion that if we can get blood pressure to normal, we will have the most health benefits," Dr. James said. "That's not necessarily true."
For people younger than 60, the goal remains blood pressure under 140/90. The panel decided to keep that target because it could not find rigorous studies that established systolic blood pressure goals for younger people.
When blood pressure guidelines were first formulated in 1977, the committee only looked at diastolic pressure. "People thought systolic should be 100 plus your age," Dr. Oparil said. "That was old folk medicine."
