When it comes to your “health numbers,” your two blood pressure values are important to know—and keep under control. New guidelines for managing high blood pressure in adults, released this morning in a report in JAMA, aim to help doctors know when to start treating high blood pressure and how best to do it.
Millions of Americans have high blood pressure, also known as hypertension. It is the most common risk factor for heart attack and stroke. High blood pressure can also lead to kidney failure, aneurysm (weakening or bulging of blood vessel walls), damaged blood vessels in the eyes, and vascular dementia (the second leading cause of memory loss and thinking problems). Unfortunately, barely half of Americans with high blood pressure have it under control.
First, some background information. Blood pressure is the force exerted on the arteries by a wave of blood propelled from the heart. It is given as two numbers, each measurement recorded in millimeters of mercury (mm Hg), like 122/78. Systolic pressure (the top number of a blood pressure reading) gauges the pressure in the arteries at systole (SIS-tuh-lee), the instant when the heart contracts and pushes a wave of blood along the arterial tree (think “s” for squeeze). Diastolic pressure (the bottom number of a blood pressure reading) is the pressure during diastole (die-AS-tuh-lee), the brief period of relaxation between beats.
What the new guidelines fail to specify is what is “normal” blood pressure and what is high blood pressure. I’m going to stick with the current standard definitions:
- Normal (meaning healthy) blood pressure: a systolic pressure under 120 and a diastolic pressure under 80.
- Hypertension, or high blood pressure: a systolic pressure of 140 or higher and/or a diastolic pressure of 90 or higher.
In a nutshell, here is what the new guidelines recommend:
- among adults age 60 and older with high blood pressure, aim for a target blood pressure under 150/90.
- among adults age 30 to 59 with high blood pressure, aim for a target blood pressure under 140/90
- among adults with diabetes or chronic kidney disease, aim for a target blood pressure under 140/90.
The expert panel that put together the guidelines also weighed in on how best to get to these targets. It recommended that everyone with high blood pressure, as well as those in the gray zone between normal and high blood pressure, adopt healthy lifestyle changes known to control blood pressure. These include losing weight if necessary, limiting salt intake, eating a diet rich in fruits, vegetables, and whole grains, and keeping physically active.
When drug therapy is needed, the guidelines recommend starting with slightly different medications depending on race. For nonblacks, including those with diabetes, it’s okay to start with an ACE inhibitor, angiotensin-receptor blocker, calcium-channel blocker, or thiazide-type diuretic. Among blacks, including those with diabetes, a calcium-channel block or thiazide-type diuretic is the best initial medication. Among individuals with declining kidney function, it’s best to start with a low dose of an ACE inhibitor or angiotensin-receptor blocker, since these types of medications help protect the kidneys from further damage.
Creating guidelines always challenges the experts
The previous set of blood pressure guidelines, published 10 years ago, were put together by a panel assembled by the National Heart, Lung, and Blood Institute (NHLBI), and carried the gravitas of a federal recommendation. The current panel was assembled by the NHLBI in 2008, but then was essentially cut loose when the institute announced it was getting out of the business of developing clinical practice guidelines.
The panel set out to base their guidelines only on data from randomized controlled trials
I applaud the panelists for what they have accomplished. This was an incredibly difficult task.
Although the new guidelines address an area of controversy—how low should blood pressure go—they don’t change the basics:
Know your blood pressure. Take advantage of any chance you have to get your blood pressure checked. For example, many pharmacies have blood pressure devices that you can use for free. Or consider using a home blood pressure monitor.
Consider high blood pressure to be a reading of 140/90 or greater. If you have high blood pressure, you need to act. This might mean just getting another couple readings in the next few weeks. If it is much above 140/90, call your doctor’s office to arrange an appointment soon.
Lifestyle changes are important. Since our lifestyles are often what lead to high blood pressure, changes can help control blood pressure. Key places to focus are getting more exercise, improving diet, losing weight if needed, not smoking, and reducing stress.
Tailor treatment to your needs. No matter what the guidelines say, your blood pressure treatment and goals should be tailored to you personally. For example, a very old and frail person is more likely to feel better and have less fall risk with fewer medications and a blood pressure higher than 150 or even 160.