CHICAGO -- Insulin pumps are used by tens of thousands of teenagers worldwide with Type 1 diabetes. But they can be risky and have been linked to injuries and even deaths, a review by federal regulators finds.

Parents should be vigilant in watching their children's use of the pumps, researchers from the Food and Drug Administration wrote. They didn't advise against using the devices. But they called for more study to address safety concerns in teens and even younger children who use the popular pumps.

The federal review of use by young people over a decade found 13 deaths and more than 1,500 injuries connected with the pumps. At times, the devices malfunctioned, but other times, teens were careless or took risks, the study authors wrote.

Some teens didn't know how to use the pumps correctly, dropped them or didn't take good care of them. There were two possible suicide attempts by teens who gave themselves too much insulin, according to the analysis.

Kelly Close, a San Francisco-based editor of a patient newsletter, said 100,000 teenagers may be using the pumps

The pumps are used for those with Type 1 diabetes, which accounts for 5 percent to 10 percent of all diabetes cases and used to be called "juvenile diabetes." The more common form is Type 2, which is often linked to obesity and more often affects adults.

Type 1 affects an estimated 12 million to 24 million people worldwide.

While some teenagers want to switch from insulin injections to pump therapy to gain more flexibility in their lives, doctors said device problems such as a blocked tube can lead quickly to dangerous episodes of high blood sugar.

"In a matter of a few hours, all the insulin in the body disappears. Metabolically, the child starts to spiral out of control," said Dr. John Buse, the American Diabetes Association's president for medicine and science. Kids need to be aware of the risk, monitor their blood sugar and be ready to give themselves an insulin injection.