This Is the Ideal Blood Pressure That Prevents Heart Disease, Says New Study

You’ve probably heard high blood pressure, or hypertension, is called a “silent killer,” and that’s for good reason. When the blood pumping through your body is pressing too hard against blood vessel walls, it can put your life at risk—but the condition is often asymptomatic, giving you no clues you’re in danger. Hypertension is also one of the largest risk factors for cardiovascular disease and stroke, the former of which is the leading cause of death around the world according to the World Health Organization.

Though it’s silent but deadly, high blood pressure is largely preventable with a healthy diet and getting regular exercise are two habits doctors widely recommend. In the U.S., doctors widely recommend a blood pressure of 120/80 as the safe zone to aim for.

But globally, that “ideal” metric varies, as two Korean medical researchers point out in a new study. For example, American and Taiwanese guidelines recommend a target systolic blood pressure level—or the top number in a blood pressure reading, which shows the pressure at which blood is leaving the heart—of less than 130 mmHg. (mmHg is the unit of measurement for blood pressure, measuring amount of mercury per millimeter. Meanwhile, diastolic blood pressure reveals the pressure of blood vessels when the heart is at rest between beats.) However, guidelines issued in Europe and China suggest a target systolic blood pressure level range between 130 and 139 mmHg and advise against it dropping below 130 mmHg.

A new retrospective cohort study published in JMIR Public Health & Surveillance sought to identify that golden number by analyzing data from the National Health Insurance Service (NHIS) database. The researchers included data from 68,901 Korean patients older than 65 years who were newly diagnosed with hypertension, had at least one NHIS check-up between 2003-2004, and had at least two check-ups during the follow-up period through 2020.

The researchers divided the participants by the 10 mmHg increment range of their systolic blood pressure levels at the first check-up:

• Less than 120 mmHg: 5,666 participants
• 120-129 mmHg: 17,236 participants
• 130-139 mmHg: 25,277 participants
• 140-149 mmHg: 14,299 participants
• 150-159 mmHg: 4663 participants
• At least 160 mmHg: 1760 participants

During the follow-up period, the researchers recorded the number of deaths in each group due to cardiovascular disease:

• Less than 120 mm Hg: 437 participants (7.7%)
• 120-129 mm Hg: 984 participants (5.7%)
• 130-139 mm Hg: 1,408 participants (5.6%)
• 140-149 mm Hg: 912 participants (6.4%)
• 150-159 mm Hg: 364 participants (7.8%)
• At least 160 mm Hg:  168 participants (9.5%)

…as well as deaths that occurred due to other health complications:

• Less than 120 mm Hg: 3,262 participants (57.6%)
• 120-129 mm Hg: 7,641 participants (44.3%)
• 130-139 mm Hg:10,833 participants (42.9%)
• 140-149 mm Hg: 6,862 participants (48.0%)
• 150-159 mm Hg: 2,745 participants (58.9%)
• At least 160 mm Hg: 1,245 participants (70.7%)

These findings revealed that participants with systolic blood pressure levels between 120 and 139 mmHg experienced the lowest rates of all-cause mortality, as well as the lowest rate of deaths related to cardiovascular disease.

According to the researchers, most guidelines for managing hypertension do not currently include a safe lower limit for blood pressure. However, this study also suggests that there could be a minimum recommended systolic blood pressure level for people with hypertension, as rates of all-cause mortality and deaths from cardiovascular disease rose for participants with a reading below 120 mmHg.