Weekly challenge: check your blood pressure, on both arms

By Deborah Kotz, Globe Staff

The next time you get your blood pressure checked, ask your health provider to take measurements on both arms. Having a difference in readings between arms could indicate a condition called peripheral artery disease, a narrowing of the blood vessels in the arms and legs that restricts blood flow to the heart and raises the risk of a heart attack and stroke.

Many doctors don’t take blood pressure readings on both arms -- despite the fact that cardiology guidelines recommend them, but a new study published in Lancet suggests this guideline should be followed.

In a review of 20 studies, the researchers found that those who had a difference between systolic readings -- the top number -- in both arms of 15 millimeters of mercury (mm Hg) or more were 2.5 times more likely to have peripheral artery disease and had a 70 percent greater risk of dying from heart disease compared with those who had no pressure differences.

The difference between the two arm measurements was a more important predictor of PAD -- which can occur on only one side of the body -- than the actual blood pressure reading.

“Ascertainment of differences should become part of routine care, as opposed to a guideline recommendation that is mostly ignored,” wrote University of Oxford researchers in an editorial that accompanied the study.

Those who do wind up with discrepant blood pressure readings, the study researchers recommended, should discuss with their doctor whether they need to be further evaluated for peripheral artery disease.