The number of kids with diabetes has skyrocketed in recent years, and the U.S. Centers for Disease Control now estimates that 2.5 million children should be screened for the disease. To make that screening easier, the American Diabetes Association in 2009 recommended a test called the Hemoglobin A1c – which doesn’t require overnight fasting – as the exclusive diabetes test for children.
But a new study from researchers at Michigan’s C.S. Mott Children’s Hospital found that method fails to identify as many as two thirds children with diabetes. Testing 254 overweight children, the study looked at the following methods:
• 1-hour glucose challenge test, where the patient doesn’t have to fast, drinks 50gm of a sugary substance and has their glucose drawn 1 hour later
• Random glucose, where the patient has glucose drawn without having to fast
• Hemoglobin A1c, a test that measures blood glucose 2 hours after the patient eats
• Fasting glucose, where the patient does not eat or drink for 8-12 hours before testing
• 2-hour glucose tolerance test, where the patient may not eat or drink for 8-12 hours, drinks 75gm of a sugary substance, and has glucose drawn two hours later
“We found that a 1-hour glucose challenge test or a random glucose were the best tests for identifying which kids have prediabetes or diabetes,” says pediatric endocrinologist Joyce M. Lee, M.D., lead author of the study. “We also looked at hemoglobin A1c, which has recently been advocated as a test for diabetes in children and adults, and found that it had poor test performance.”
Lee says that fasting glucose and the 2-hour glucose tolerance test remain the “gold standard for defining prediabetes or diabetes,” but because it’s inconvenient to have kids return for a second office visit for a blood draw, she and colleagues decided to evaluate the nonfasting tests – 1-hour glucose, random glucose and hemoglobin A1c.
Because their study found that hemoglobin A1c missed two of three children that the fasting tests identified as having diabetes or prediabetes, the researchers are urging that the 1-hour glucose or random glucose tests be used in kids instead.