The Food and Drug Administration is warning people who use one of several glucose meters made by Abbott Diabetes Care that they can give misleading readings.
In some cases, mistaken readings have resulted in diabetics' blood sugar becoming dangerously high, the FDA said in a statement issued Wednesday.
The mistaken readings happen when the meters are accidentally switched to give a person's blood sugar level in the foreign standard of units, millimoles per liter, resulting in a number that a diabetic can misinterpret as in the U.S. standard of units, milligrams per deciliter.
An inaccurate reading can lead a diabetic to take the wrong dose of insulin or make incorrect dietary changes.
The switch can occur when someone is setting the time and date on the meter. The FDA also has reports of the switch taking place after a meter was dropped or its battery replaced, although the manufacturer has not confirmed this.
Abbott Diabetes Care is based in Alameda, Calif. In a statement, the company said 2.25 million people use these products. They are not being recalled.
New glucose meters are being shipped with the proper unit of measurement locked in, the FDA said.
Users should refer to the owner's manual or contact Abbott Diabetes Care at 1-800-553-4105 to change their meters. The FDA recommended anyone who believes they have been using the wrong read-out for some time and are worried about their health should contact a doctor.
The affected Abbott glucose meters sold in the United States are: FreeStyle, FreeStyle Flash, FreeStyle Tracker, Precision Xtra, MediSense, Sof-Tact, Precision Sof-Tact, MediSense, Optium, and private label brands ReliOn Ultima, Rite Aid, and Kroger blood glucose meters, the FDA said.
Affected glucose meters sold outside of the United States are: Xceed, Liberty, Boots, Xtra Classic, Easy, and SofTrac, the agency said.