The greater the blood pressure difference between the arms…
An extensive international study, funded by the National Institute for Health Research (NIHR), and recently published in the journal Hypertension, provides important evidence for the first time and confirms that a difference in blood pressure (BP) values between arms is associated with a higher risk of heart attack, stroke and death. The greater the difference in blood pressure between the arms, the greater the additional risk to the patient’s health.
This information resulted from a meta-analysis of 24 global studies, gathering a database of almost 54,000 people, the research being conducted by the University of Exeter. The data included adults from Europe, USA, Africa and Asia, for which BP records were available for both arms.
Blood pressure is measured in units of millimeters of mercury (mmHg), and its value is always given by two numbers: the upper value (systolic), which represents the maximum blood pressure, and the lower value (diastolic), which represents the minimum blood pressure. High systolic blood pressure indicates hypertension. It affects a third of the adult population and is the only global leading cause of preventable heart attacks, strokes and deaths. A significant difference between systolic blood pressure measurements in both arms could be extremely suggestive of a narrowing or stiffening of the arteries, which can affect blood flow. These arterial changes are recognized as an additional risk marker for heart attack.
Currently, international guidelines on blood pressure recommend that health professionals measure blood pressure in both arms when assessing cardiovascular risk, but this is largely ignored. The present study provides a new upper limit of “normal” for a difference in arm blood pressure, which is significantly lower than the current recommendation. Research could lead to a change in international guidelines for hypertension, which would mean that more patients at risk could be identified and receive life-saving treatment.
“It has long been known that the difference in blood pressure between the two arms is linked to poorer health outcomes, but the large number involved in this study now help us better understand this. The study tells us the following: the greater the difference in blood pressure between the arms, the greater the cardiovascular risk, which means that BP should be measured in both arms to determine which patients may be at significant risk. Patients who need a blood pressure check should now expect to be checked on both arms at least once,” said Dr. Chris Clark, lead coordinator of the study at the University of Exeter Medical School.
“Checking one arm, then the other, with a common blood pressure monitor is cheap and can be performed in any medical setting, without the need for expensive equipment. While international guidelines currently recommend doing so, it only happens about half the time, most often due to time constraints. Our research shows that the little extra time needed to measure both arms could ultimately save lives,” he added.
The researchers concluded that each difference in mmHg found between the two arms predicted an increased risk of 10 years for one of the following conditions: angina, heart attack or stroke.
Currently, both British and European guidelines recognize a systolic difference of 15 mmHg or greater between the two arms as an indicative threshold for additional cardiovascular risk. This new study found that a threshold of less than 10 mmHg was clearly indicative of an additional risk, which would mean that many more people would have to be considered for treatment if there was such a difference between the measured values.
Treating high blood pressure requires both drug treatment and a number of healthy habits and nutritional measures, generically called lifestyle changes. These measures are sufficient to normalize blood pressure in case of moderate hypertension. The Dahna phone app is your ally for a healthy lifestyle and you can download it for free from AppStore or Google Play.