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Tests and diagnosis

By Mayo Clinic staff

If your child's doctor suspects diabetes, he or she will recommend a screening test. The primary test used to diagnose diabetes in children is the:

  • Random blood sugar test. A blood sample will be taken at a random time. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Regardless of when your child last ate, a random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher suggests diabetes.

If your child's random blood sugar test results don't suggest diabetes, but your doctor still suspects it because of your child's symptoms, you doctor may do a:

  • Glycated hemoglobin (A1C) test. This blood test indicates an average blood sugar level for the past two to three months. It works by measuring the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher the blood sugar levels, the more hemoglobin that has sugar attached. An A1C level of 6.5 percent or higher on two separate tests indicates diabetes. A result between 6 and 6.5 percent is considered prediabetes, which indicates a high risk of developing diabetes.

Another test your doctor might use is a fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, your child will be diagnosed with diabetes.

If your child is diagnosed with diabetes, your doctor will also run blood tests to check for autoantibodies that are common in type 1 diabetes, and help doctors distinguish between type 1 and type 2 diabetes. The presence of ketones — byproducts from the breakdown of fat — in your child's urine also suggests type 1 diabetes, rather than type 2.

After the diagnosis
Once your child has been diagnosed with type 1 diabetes, he or she will regularly visit his or her doctor to ensure good diabetes management.

During these visits, the doctor will also check your child's A1C levels. Your child's target A1C goal may vary depending on his or her age and various other factors, but the American Diabetes Association generally recommends that A1C levels be below 7 percent, which translates to an estimated average glucose of 154 mg/dL (8.5 mmol/L). The American Diabetes Association recently developed a formula to translate the A1C into an estimated average glucose (eAG) because it more closely correlates with daily blood sugar readings.

Compared with repeated daily blood sugar tests, A1C testing better indicates how well your child's diabetes treatment plan is working. An elevated A1C level may signal the need for a change in your child's insulin regimen or meal plan.

In addition to the A1C test, the doctor will also take blood and urine samples periodically to check your child's cholesterol levels, thyroid function, liver function, kidney function and to test for celiac disease. The doctor will also examine your child to assess his or her blood pressure and growth, and will check the sites where your child tests his or her blood sugar and delivers insulin.

Treatments and drugs Preparing for your appointment
References
  1. The dangerous toll of diabetes. American Diabetes Association. http://www.diabetes.org/diabetes-statistics/dangerous-toll.jsp. Accessed Jan. 6, 2009.
  2. Levitsky LL, et al. Epidemiology, presentation, and diagnosis of type 1 diabetes mellitus in children and adolescents. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  3. Eisenbarth GS, et al. Pathogenesis of type 1 diabetes mellitus. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  4. McCulloch DK. Glycemic control and vascular complications in type 1 diabetes mellitus. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  5. Kidney disease (nephropathy). American Diabetes Association. http://www.diabetes.org/utils/printthispage.jsp?PageID=TYPE1DIABETES3_232930. Accessed Jan. 6, 2009.
  6. What is diabetes: Diabetes complications. Juvenile Diabetes Research Foundation. http://www.jdrf.org/index.cfm?page_id=101308. Accessed Jan. 6, 2009.
  7. Prevent diabetes problems: Keep your eyes healthy. National Institute of Diabetes and Digestive and Kidney Diseases. http://diabetes.niddk.nih.gov/dm/pubs/complications_eyes/index.htm. Accessed Jan. 6, 2009.
  8. McCulloch DK. Patient information: Preventing complications in diabetes mellitus. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  9. Skin complications. American Diabetes Association. http://www.diabetes.org/utils/printthispage.jsp?PageID=TYPE1DIABETES3_232934. Accessed Jan. 6, 2009.
  10. What people with diabetes need to know about osteoporosis. National Institute of Arthritis and Musculoskeletal and Skin Diseases. Accessed Jan. 9, 2009.
  11. Levitsky LL, et al. Management of type 1 diabetes mellitus in children and adolescents. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  12. Standards of medical care in diabetes -2009. Alexandria, Va.: American Diabetes Association. http://care.diabetesjournals.org/content/vol31/Supplement_1/. Accessed Jan. 28, 2009.
  13. Estimated average glucose, eAG. American Diabetes Association. http://professional.diabetes.org/GlucoseCalculator.aspx. Accessed Jan. 6, 2009.
  14. The basics of insulin. American Diabetes Association. http://www.diabetes.org/utils/printthispage.jsp?PageID=TYPE1DIABETES3_263601. Accessed Jan. 6, 2009.
  15. McCulloch DK. Patient information: Insulin therapy in type 1 diabetes mellitus. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  16. Levitsky LL, et al. Complications and screening in children and adolescents with type 1 diabetes mellitus. http://www.uptodate.com/home.index.html. Accessed Jan. 5, 2009.
  17. Robertson RP. Pancreas and islet transplantation in diabetes mellitus. http://www.uptodate.com/home.index.html. Accessed Jan. 6, 2009.
  18. Low blood sugar: Definition, symptoms. Juvenile Diabetes Research Foundation. http://www.jdrf.org/index.cfm?fuseaction=home.viewpage&page_id=EC9AC822-1321-C844-13C1013CF597E42F. Accessed Jan. 6, 2009.
  19. High blood sugar: Definition, symptoms. Juvenile Diabetes Research Foundation. http://www.jdrf.org/index.cfm?fuseaction=home.viewpage&page_id=EC92D98E-1321-C844-13EB771367A49526. Accessed Jan. 6, 2009.
  20. Ketoacidosis. American Diabetes Association. http://www.diabetes.org/type-1-diabetes/ketoacidosis.jsp. Accessed Jan. 6, 2009.
  21. Collazzo-Clavell M (expert opinion). Mayo Clinic, Rochester, Minn. Jan. 21, 2009.
  22. Diabetes and teens. Juvenile Diabetes Research Foundation. Accessed Jan. 20, 2009.
  23. Stalvey MS. Fifty years ago in the Journal of Pediatrics. Journal of Pediatrics. 2007: 150(1) http://www.mdconsult.com/das/article/body/115791309-2/jorg=journal&source=&sp=16726925&sid=788957128/N/562819/1.html?issn=0022-3476. Accessed Jan. 6, 2009.
  24. What is Type 1 Diabetes TrialNet? Type 1 Diabetes TrialNet. http://www.diabetestrialnet.org/about/index.htm. Accessed Jan. 6, 2009.
  25. International Expert Committee. International Expert Committee report on the role of the A1C assay in the diagnosis of diabetes. Diabetes Care. 2009;32:1.

DS00931

June 13, 2009

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