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New guidelines suggest that people over 60 can have a higher blood pressure than previously recommended before starting treatment to lower it. The advice, criticized by some physicians, changes treatment goals that have been in place for more than 30 years.
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.”
Observational studies then found that systolic pressure was a better predictor of consequences like strokes. Researchers began to test the effects of lowering systolic blood pressure, but their studies excluded younger people because they were looking for outcomes, like strokes or heart failure, that are more common in older people. As a result, there are no good studies showing that younger people benefit from taking drugs to achieve a particular systolic pressure.
Some experts not on the committee said that the blood pressure guidelines were based on limited science — studies did not specifically test the effects of getting blood pressure below 140/90 — but that this did not mean the goal should be abandoned.
“When I discuss this with my colleagues and friends in the community, most are pretty livid,” said Dr. George Bakris, the director of the hypertension center at the University of Chicago. “Is this the golden age of Sparta? What is going on?”
The old blood pressure targets made a huge difference in patients’ health, said Dr. Marvin Moser, a hypertension expert, who was the chairman of the first blood pressure guidelines committee in 1977 and a member of the six committees after that, but not of the most recent one.
“The thing about hypertension is that it is a dull disease, but the results of treatment are spectacular,” he said. The incidence of strokes has fallen by 70 percent since 1972, and heart failure rates have fallen more than 50 percent.
“It used to be that every third or fourth hospital bed had someone with hypertension in it,” Dr. Moser said. “Today it is very rare to find someone with malignant hypertension” — that is, dangerously high and uncontrolled blood pressure.
It is inexpensive now to treat the disorder, Dr. Moser added, because 90 percent of blood pressure drugs are available as generics.
But, Dr. James said, some people may be better off taking fewer drugs or lower doses. Many older people take multiple medications, which can interact and potentially cause harm, he said.
Some people, too, end up with blood pressures so low when they stand that they get dizzy.
“A lady who gets dizzy and falls and fractures her hip — that’s a terrible thing,” Dr. James said.
The guidelines committee’s paper is accompanied by three editorials, two of which praise the process and note the rigor with which the group assessed evidence.
The third — by Dr. Eric D. Peterson of Duke University, Dr. J. Michael Gaziano of the VA Boston Healthcare System and Brigham and Women’s Hospital, and Dr. Philip Greenland of Northwestern University — said the committee should have considered evidence that fell short of randomized, controlled clinical trials.
“We’re not starting from square one,” Dr. Gaziano said in a telephone interview. “We’ve got a history of how to manage patients. The bar for changing that should be pretty high.”
Dr. Bakris said that the committee was merely proposing guidelines, and that doctors should continue to use their judgment.
“These are not stone tablets of Moses,” he said.
But, the writers of the critical editorial noted, doctors today are expected to follow performance measures.
Half of people taking drugs do not achieve the current goal of blood pressure under 140/90, and the writers expressed concern that with the new, more lenient target, patients’ blood pressures would edge even higher.