New research finds that large spikes in blood pressure among young adults are associated with a higher risk of cardiovascular disease in middle age. As a result, physicians may need to revisit the practice of averaging blood pressure readings to determine if medication is necessary.
Dr. Yuichiro Yano, Ph.D. — an assistant professor in the Department of Family Medicine and Community Health at Duke University in Durham, NC — is the lead author of the new paper.
Dr. Yano and colleagues started out from existing United States Preventive Services Task Force and American College of Cardiology/American Heart Association recommendations.
These suggest that doctors should use an average of several blood pressure measurements over time to diagnose and manage hypertension in young adults.
Some studies, however, have suggested that higher variability in blood pressure readings from visit to visit is linked with a higher risk of cardiovascular disease — particularly in adults over the age of 50.
So, could it be that higher variability in blood pressure readings in young adulthood means a higher risk of adverse cardiovascular events later in life?
To find out, Dr. Yano and team used data from the Coronary Artery Risk Development in Young Adults Study.
In total, they assessed the blood pressure readings of 3,394 participants from across four U.S. states.
Specifically, the researchers examined mean (average) blood pressure readings, cumulative blood pressure exposure, visit-to-visit variability, and average annual change in blood pressure.
The participants were African American and white adults aged 18–30 years, all of whom took part in the study between March 1985 and August 2015. During this time, the adults participated in follow-up examinations at 2, 5, 7, 10, 15, 20, 25, and 30 years.
Almost 46% of the participants were African American, and nearly 56% were women.
The main focus of the study was systolic blood pressure, which refers to the upper number in blood pressure readings. A systolic reading of over 130 millimeters of mercury (mm Hg) tends to be a marker of hypertension.
Around 10 years into the study, the participants were 35 years old, on average. Dr. Yano and colleagues identified the young adults who had shown variations in their systolic blood pressure and continued to monitor them over the next 2 decades in order to examine a potential link with cardiovascular disease.
During the study period, 181 people died and 162 adverse cardiovascular events occurred. These included coronary heart disease, heart failure, stroke, transient ischemic attack, and stent procedures for peripheral artery disease.
The scientists found that for each blood pressure spike of 3.6 mm Hg in young adulthood, the risk of cardiovascular disease was 15% higher in the following 20 years.
These results were independent of the average blood pressure readings in young adulthood.
“If a [person] comes in with one reading in December and a significantly lower reading in January, the average might be within the range that would appear normal,” explains Dr. Yano.
“But is that difference associated with health outcomes in later life? […] That’s the question we sought to answer in this study, and it turns out the answer is yes.”
Dr. Yano goes on to explain that patients and physicians alike should consider blood pressure variability in early adulthood more. Early detection means that a person can make lifestyle changes to prevent the development of hypertension later on.
“Current guidelines defining hypertension and assessing the need for antihypertensive therapies ignore variability in blood pressure readings,” he says.
“I think there has been a belief that variability is a chance phenomenon, but this research indicates maybe not. Variability matters.”