THE QUESTION Blood pressure checks usually involve inflating and then deflating a cuff that’s wrapped around the upper part of one arm or the other. Might checking the pressure in both arms be valuable?
THIS STUDY analyzed data from 20 studies, involving 16,428 people who had blood pressure readings taken in both arms. The studies reported only systolic pressure — the top number, indicating the pressure when the heart is pumping blood and measured in millimeters of mercury (mm Hg). People whose systolic pressure varied by 15 mm Hg or more between their two arms were at greater risk for vascular disease than those whose blood pressure readings were similar between right and left arms. People with differing blood pressure levels were more than twice as likely to have peripheral vascular disease, which includes damaged or blocked arteries or veins away from the heart, such as in the legs and feet, and nearly twice as likely to have cerebrovascular disease, which affects blood flow to the brain and can contribute to dementia. People whose blood pressure varied between their arms also had an increased risk for dying from a cardiovascular problem.
WHO MAY BE AFFECTED? People whose systolic pressure in one arm differs from the other. Peripheral vascular disease often shows no symptoms, but early detection can allow actions — such as stopping smoking or adding medication to lower cholesterol or blood pressure — aimed at lessening the likelihood of heart problems, a stroke or even death. The American Heart Association recommends that doctors measure blood pressure in both arms during a patient’s first visit.
CAVEATS The study did not include data on diastolic pressure, the lower number in a blood pressure reading, representing pressure when the heart is at rest. Most participants in the studies had greater-than-average risk for cardiovascular problems; whether the findings apply to people without such risk is unclear.
FIND THIS STUDY Jan. 30 online issue of the Lancet (www.
The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.