If diabetes is suspected, your child's doctor will likely recommend a screening test. A diagnosis of type 2 diabetes in children generally requires abnormal results from two tests taken on different days. There are several blood tests for diabetes.
Fasting blood sugar test
A blood sample is taken after your child fasts for at least eight hours, or overnight. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).
- A fasting blood sugar level below 100 mg/dL (5.6 mmol/L) is considered normal.
- A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 7.0 mmol/L) is considered prediabetes — which indicates a high risk of developing type 2 diabetes.
- A fasting blood sugar level of 126 mg/dL (7.0 mmol/L) or higher indicates type 2 diabetes.
Glycated hemoglobin (A1C) test
Your doctor might recommend this test if your child's fasting blood sugar test results don't indicate diabetes but the doctor still suspects it.
The A1C test indicates your child's average blood sugar level for the past two to three months. Specifically, the test measures the percentage of blood sugar attached to the oxygen-carrying protein in red blood cells (hemoglobin). The higher your child's blood sugar levels, the more hemoglobin your child will have with sugar attached.
- An A1C level below 5.7 percent is considered normal.
- An A1C level between 5.7 and 6.4 percent is considered prediabetes.
- An A1C level of 6.5 percent or higher on two separate tests indicates type 2 diabetes.
Oral glucose tolerance test
A blood sample is taken after your child fasts for at least eight hours or overnight. Then your child drinks a sugary solution, and his or her blood sugar levels are measured periodically over the next few hours.
- A blood sugar level less than 140 mg/dL (7.8 mmol/L) is considered normal.
- A blood sugar level from 140 to 199 mg/dL (7.8 to 11.0 mmol/L) is considered prediabetes.
- A blood sugar level of 200 mg/dL (11.1 mmol/L) or higher indicates type 2 diabetes.
Random blood sugar test
A blood sample is taken at a random time. Regardless of when your child last ate, a random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes.
Your doctor will likely recommend additional tests to confirm the type of diabetes that your child has. It's important to distinguish between type 1 diabetes and type 2 diabetes because treatment strategies differ.
After the diagnosis
Your child will need regular follow-up appointments to ensure good diabetes management and to check his or her A1C levels. Your doctor will also periodically use blood and urine tests to check your child's:
- Cholesterol levels
- Thyroid function
- Kidney and liver function
In addition, your doctor will regularly assess your child's blood pressure and growth. Your child will also need regular eye examinations.