In a study published in the Journal of Diabetes Science and Technology, researchers compared patients’ satisfaction with fingertip blood sugar testing and testing using an alternate site, in this case the palm of the hand. They found that people who test their blood sugar levels four times a day like the idea of using alternative site testing approaches. However, they also found that testing on their palm with regular lancing supplies didn’t always provide easy access to get enough blood for a test strip.
Managing Diabetes With Alternate Site Testing: The Choices
“The palm of the hand is good because it’s capillary blood and it’s going to be current blood sugar,” said certified diabetes educator Sacha Uelmen, RD, program director of the outpatient diabetes education program at the University of Michigan Health System in Ann Arbor. Your thumb is another option if you’re tired of using fingers. Other possible locations include the thigh, calf, upper arm, and forearm. However, sites other than your palm are recommended only if your blood sugar is stable at the time of testing. Certified diabetes educator Hector Verastigui, RN, clinical research coordinator at the Texas Diabetes Institute in San Antonio, said he teaches patients to test using their arms as an option if they are interested in alternate site testing. However, there are disadvantages to this method as well. “Most patients that I teach alternative site testing will say that forearm testing is less painful but difficult to obtain a blood sample, and most patients will return to fingertip testing,” Verastigui said. He also tells people to be aware of the timing difference in blood glucose between forearm and fingertip. “A blood glucose result taken at the fingertip will not reach the forearm capillaries for 20 to 30 minutes," he said. “This is important because if a patient is testing for a possible low blood sugar reaction and if they use alternative site testing, their meter may display a normal value and not a true blood sugar result, which may delay treatment.” So if you’re concerned about the timing of testing, it might be best to stick with finger testing. Uelmen has had patients who tested using their arms and one patient who successfully used his earlobe — “a good option if you can do it,” she said. But she pointed out that, at least in Michigan, where it is cold for a significant part of the year, most people do not use their legs for testing because of the hassle of taking off clothes. She also advised a conservative approach for people who are uncertain of their blood sugar levels. “If you’re afraid you’re low or if your blood sugar is changing, you need to use your hands,” she said. “But if you’re just curious about your body’s response to something — such as, how did that meal do? — you could use your arms or an alternate site.” Above all, she advised checking in with your diabetes educator if you want to try an alternative site. You’ll want to make sure that your lancing device can be used for the site you’re considering and you’ll need to find out how to adjust lancing depth, if necessary. One possible drawback of alternate site testing is the cost of test strips if you feel you can’t rely on the results and end up testing (again) using your finger. Other drawbacks include the fear of testing pain and scarring, although many people worry about these impacts from lancing their fingers as well.
When You Must Stick to the Fingertip
In certain situations, you should not do alternate site testing. These include:
If you just took insulinIf you think your blood sugar level could be lowIf you are not always aware when your blood sugar level drops very lowIf you are sick or stressedIf you just exercised or just ate
Talk with your diabetes educator or another member of your medical team if you think alternative site testing could be for you. You might be on to something — getting good information about blood sugar levels and giving your fingers a break at the same time.
