Standing blood pressure test more accurate in detecting hypertension

Measuring blood pressure while patients are standing rather than sitting may improve the accuracy of readings, UT Southwestern Medical Center researchers in the US report.

Their findings, published in Scientific Reports, could lead to significant improvements in early detection of high blood pressure in healthy adults.

“Blood pressure screening is predominantly performed when patients are sitting down in the doctor’s office,” said lead author Wanpen Vongpatanasin, M.D., Professor of Internal Medicine and Director of the Hypertension Section in the Division of Cardiology at UT Southwestern.

“However, it has limited sensitivity and reliability as it does not reflect blood pressure in real living situations where we often stand or walk.

“Our study shows that measuring blood pressure in the standing position may offer a more accurate way to determine if someone has hypertension, which requires assessment of a 24-hour ambulatory blood pressure monitor or home monitoring.”

Hypertension, or high blood pressure, remains the main risk factor for cardiovascular disease and stroke, affecting 48 per cent of adults in the United States. According to the Centers for Disease Control and Prevention, in 2021 hypertension was a primary or contributing cause for over 690,000 deaths in the US.

UTSW researchers measured the blood pressure of 125 healthy patients ages 18-80 with no history of hypertension, previous use of blood pressure medication, or other comorbidities.

The statistical analysis used to assess the overall accuracy of each test in diagnosing hypertension revealed that measuring standing blood pressure either on its own or in addition to sitting blood pressure significantly improved diagnostic accuracy.

Researchers used several established guidelines for defining hypertension, including those of the American Heart Association.

Blood pressure was measured in three ways: through 24‐hour ambulatory blood pressure monitoring (ABPM), seated in the doctor’s office, and standing in the office. The sensitivity (accuracy in detecting a condition, or a “positive” result) and specificity (accuracy in detecting absence of a condition, or a “negative” result) for detecting hypertension in the seated measurements were 43 per cent and 92 per cent, while the sensitivity and specificity in the standing measurements were 71 per cent and 67 per cent.

Based on average 24-hour ABPM measurements, researchers found that 33.6 per cent of participants had hypertension. Of those with hypertension, the average age was 55.7 years old and 57 per cent were female adults, 55 per cent were white adults, 29 per cent were Black adults, 16 per cent were Asian adults, and 16 per cent were of Hispanic/Latino ethnicity. Of the participants without hypertension, the only significant difference in demographics observed was younger age (45.3 years old). Data from the UTSW Dallas Heart Study was used to determine blood pressure levels in the office, home, and 24-hour ABPM that are optimal for cardiovascular health.

Findings from this research create an opportunity for improved diagnosis of hypertension in healthy adults and could lead to better diagnostics for patients who already have the condition.

“This study was performed in healthy adults without diagnosis of hypertension or antihypertensive drug treatment,” Dr. Vongpatanasin said. “We need to determine if standing blood pressure will offer a better diagnostic tool than seated blood pressure in caring for hypertensive patients treated with medications.”

Other UTSW researchers who contributed to this study are first author John M. Giacona, M.P.A.S., PA-C, Physician Assistant, Internal Medicine; Weerapat Kositanurit, M.D., visiting Assistant Professor of Internal Medicine; Jijia Wang, Ph.D., Assistant Professor of Applied Clinical Research in the School of Health Professions; Jon Williamson, Ph.D., Dean and Professor in the School of Health Professions; Scott Smith, Ph.D., Associate Dean for Research, Professor, and Chair in the School of Health Professions; Ursa Petric, medical student; and Danielle Pittman, B.S.N., RN, CEN, Senior Business Analyst.

Dr. Vongpatanasin holds the Norman and Audrey Kaplan Chair in Hypertension and the Fredric L. Coe Professorship in Nephrolithiasis Research in Mineral Metabolism. Dr. Williamson holds the Arnold N. and Carol S. Ablon Professorship in Biomedical Science and is a Distinguished Teaching Professor. Dr. Smith holds the Jere H. Mitchell, M.D. Distinguished Professorship in Clinical Research and is a Distinguished Teaching Professor.

This study was funded by grants from the National Institutes of Health (R01HL133179, R01AG057571, R01HL133179, and T32DK007257).