One U.S. adult out of every three has high blood pressure, which increases the risk of heart disease and stroke. But the number of people with elevated blood pressure, not yet in the high range, is much higher.
According to a new analysis published in the Journal of the American Medical Association, based on more than 8 million people from 154 countries across 844 studies, the problem of elevated blood pressure is worldwide, and it has serious consequences.
The researchers were particularly interested in the top number of a blood pressure reading, called systolic pressure, which measures pressure in the blood vessels when the heart is beating. This number can escalate quickly in older adults. Elevated systolic blood pressure of at least 110-115 millimetres of mercury (mmHg) has been linked to heart disease, kidney and cerebrovascular disease and stroke.
Even though blood pressure medication isn’t typically used until a person reaches 140 mmHg, the researchers wanted to see the link between these lower levels and bad health outcomes. “We think it’s important to measure the lost health between 115 and 140 mmHg, even though we do not yet know whether giving all of those people blood pressure lowering medications would be beneficial,” says Dr Gregory Roth, one of the study’s authors and assistant professor in the division of cardiology at the University of Washington.
The number of people with elevated systolic blood pressure has increased dramatically in the past 25 years, and so has the rate. “We found that 3.5 billion adults have blood pressure high enough to bring some risk, and 870 million people around the world are hypertensive,” says Roth.
Elevated systolic blood pressure was found to be a leading contributor to preventable death in 2015 and was linked to more than 10 million deaths—1.4 times the number in 1990.
Countries with very large populations—especially China, India, Russia, Indonesia and the U.S.—lost the most health due to heightened blood pressure. Yet “elevated systolic blood pressure is a risk in almost every population in the world,” Roth says. Part of the reason why is likely that blood pressure lowering medications, though effective, aren’t accessible or cheap enough for many people with hypertension who need them.
The new study adds to recent evidence that blood pressure readings even lower than the guidelines recommend may be beneficial. The 2015 results of the clinical SPRINT—short for the systolic blood pressure intervention—trial found that people who kept their systolic blood pressure at 120, compared to those who kept their blood pressure at the recommended level of 140, had much lower rates of heart-related deaths and early deaths from any cause.
Not everyone needs to take a medication for elevated systolic blood pressure. It’s possible to lower your blood pressure naturally through changes in diet, exercise and weight, Roth says. The important thing is to start paying attention to blood pressure early. “Elevated blood pressure starts contributing to a very large amount of lost health at a relatively young age,” Roth says.