Doctors usually only measure one arm for blood pressure, but a new hypertension study suggests they should check both. The difference between the two measurements can indicate an increased risk of cardiovascular disease and death.
The researchers combined data from 24 previous studies that measured bilateral blood pressure in 53,827 men and women over the age of 18. The studies only included people who were examined in general clinics and eliminated all people who were seen in special cardiac situations.
There were a total of 4,939 deaths from all causes, including 1,435 deaths related to cardiovascular disease and 5,800 fatal and non-fatal cardiovascular events, including heart attack, angina, or stroke. After adjusting for age, sex, smoking, and diagnosing diabetes and high blood pressure, they found that for every 5 millimeter increase in the difference between the systolic values of the left and right arms (the highest number), the risk of 5 percent increased death for whatever reason, a 6 percent increase in cardiovascular death and a 9 percent increase in the risk of a first cardiovascular event.
"This large study gives some precision to the numbers," said lead author Christopher E. Clark, a senior clinical lecturer at the University of Exeter Medical School in England. "A difference of 10 millimeters between the weapons means a 10 percent increase in risk. This is significant enough to divide people into groups that should be treated more aggressively."