Researchers from the University of Alabama published their findings on Wednesday in the JAMA Network.
Hypertension, or high blood pressure, is a common, but dangerous condition, according to the Centers for Disease Control and Prevention (CDC). It increases the risk of heart disease and stroke, and the CDC says those with hypertension “might be at an increased risk for severe illness from COVID-19," though the study authors said it's uncertain.
The researchers used data from the U.S. National Health and Nutrition Examination Survey to assess any changes in blood pressure control among U.S. adults with hypertension from 1999 through 2018.
A hypertensive state was defined as systolic blood pressure (top number) over 140 mm Hg and diastolic figure (bottom number) higher than 90mm Hg. According to Healthline, systolic pressure "refers to the amount of pressure in your arteries during the contraction of your heart muscle," whereas diastolic pressure, the bottom number, "refers to your blood pressure when your heart muscle is between beats."
Of more than 18,000 adults with hypertension, the proportion with blood pressure control increased from nearly 32% in 1999-2000 to almost 49% by 2007-08. Researchers said blood pressure control then stabilized through to 2013-14 at nearly 54% before dropping to less than 44% by 2017-18.
When researchers applied more stringent blood pressure guidelines released in 2017 from the American College of Cardiology and American Heart Association (listing hypertension as a reading of 130/80mmHg or higher), they found that just 19% of U.S. adults had their blood pressure under control.
Federal recommendations suggest annual blood pressure screenings for adults over 40, and for younger adults at-risk.
"In the current study, a substantial percentage of adults aged 18 to 44 years with hypertension were not aware they had hypertension. Efforts are needed to ensure BP screening occurs for younger adults," study authors wrote, noting that additional efforts are needed to start and maintain antihypertensive medication among younger adults.