WSU associate dean: Logic’s behind blood pressure guidelines

If your last blood pressure check at the doctor’s office didn’t raise concerns, new medical guidelines could change that in 2018.

The mark now considered to be high blood pressure is 130/80, compared with the previous 140/90, under new guidelines released in November by the American Heart Association and the American College of Cardiology.

The shift likely will catch millions of Americans by surprise because they previously got a pass from doctors, said internal medicine physician Dawn DeWitt in Spokane. Many newly diagnosed won’t go on medication but rather will be told to make lifestyle changes, she said, such as to exercise regularly.

“The logic behind the new guidelines is that the sooner high blood pressure is diagnosed and treated, the greater the chance of preventing problems,” said DeWitt, associate dean of clinical education at Washington State University’s Elson S. Floyd College of Medicine.

It’s a move recognizing a general consensus that heart disease and strokes are the No. 1 killer of Americans, and that’s gotten worse with the obesity epidemic rising since the 1970s, she said.

The AHA defines high blood pressure, also known as hypertension, as being when the force of the blood flowing through your blood vessels is consistently too high. The body’s tissues and organs need the oxygenated blood that the circulatory system caries.

“They released these new guidelines saying to some degree, all these heart attacks and strokes are quote, preventable. It’s saying if we treat hypertension better, we can prevent or delay many of these events, a lot of which are either severely debilitating or life-ending, so it’s not a small thing.”

The change also acknowledges that heart disease and related conditions generally develop as a long-term process, DeWitt said.

“It’s not like your arteries are perfect one week and the next week, boom, you’ve got a heart attack,” she said. “It takes time. Other than smoking, obesity and hypertension are the two biggest entwined factors for the general population.”

Obesity is significant also in light of its higher rates. Over recent decades, rates within the U.S. population in the overweight and obese categories have increased significantly, according to DeWitt. Generally, blood pressure increases as people gain weight, she said.

About 85 million U.S. adults, or one in three, have high blood pressure, according to an initiative called Target BP, a project of the AHA and American Medical Association. Launched in 2015, Target BP offers support while urging medical services and patients to prioritize blood pressure control.

When the heart beats, it creates pressure that pushes blood through a network of tube-shaped blood vessels, including arteries, veins and capillaries. This pressure — blood pressure — is the result of two forces. The first is systolic pressure occurring as blood pumps out of the heart and into the arteries. The second is diastolic pressure, created as the heart rests between heart beats, the AHA says.

These two forces are represented by the numbers in a blood pressure reading.

The new guidelines have both financial and psychological impacts, DeWitt said. The cost could be in lifestyle changes — paying for more doctor visits, lifestyle coaching, gym memberships or medication. Psychologically, some people who never had a disease suddenly receive a hypertension label, she said.

“The implications of making that announcement are that overnight millions and millions more Americans would be classified as having hypertension,” DeWitt said. And it might be considered a pre-existing condition, potentially shaking ground if there are any future reforms affecting health insurance coverage, she added.

Medical research and history since the 1960s regarding what constitutes high blood pressure is also complicated, said DeWitt, although medical experts generally agree about its link to heart disease.

“It’s a fascinating story because the evidence about blood pressure over the years has been up and down, shall we say, no pun intended,” DeWitt said. “For few years, doctors sort of thought anything that wasn’t really high, so 160 over 90, wasn’t too bad.”

In the 1960s, doctors had only about two drugs available to treat high blood pressure, she said. Then studies in the 1980s and 90s shed some light that lower blood pressure was good, but still, guidelines tended to go back and forth between 140/90 and 130/80.

Meanwhile, the number of medications available to treat hypertension increased, creating a more complicated landscape today, added DeWitt.

“Over half of adults require three or more medications to control blood pressure to 140 over 90,” she said. “At that point, 50 to 60 percent of Americans are rated as uncontrolled by their chart.”

Additionally, researchers consider there is a significant amount of “white coat hypertension,” DeWitt said. The term refers to when people have a medical office visit and experience stress over getting to the appointment on time, parking, paperwork and insurance, etc., “so they get into doctor’s office, and their blood pressure is higher.”

“It became pretty clear that ambulatory blood pressure monitoring, where somebody wears a monitor for 24 hours, is more accurate in terms of predicting downstream complications of high blood pressure.

“We decided home blood pressure monitoring was probably better than office blood pressure monitoring, but blood pressure cuffs aren’t cheap. For lay people to use them, you generally need automated ones that aren’t always accurate, so there are all kinds of factors.

“Are we measuring blood pressure correctly, or are people walking around with lower blood pressure than we get in the office?”

Cholesterol and diabetes are other contributing factors toward heart disease for some patients. Salt intake is somewhat controversial within the topic, she said, but for some people, reducing salt can make a significant difference.

“Smoking goes without saying,” she said. “The next implication on the good side is that most people classified with hypertension, they have the option for treatment with lifestyle changes, to lose a few pounds, increase exercise, decrease salt and junk food and stop smoking.”