Diagnosis of type 2 diabetes
Only a blood test analyzed in the laboratory can make a diagnosis of diabetes.
The table below shows the diagnostic values for prediabetes and diabetes from Diabetes Canada’s 2018 Clinical Practice Guidelines for the Prevention and Treatment of Diabetes in Canada:
| Prediabetes | Type 2 diabetes | |
|---|---|---|
| Fasting blood glucose (AC blood glucose) | Between 6.1 and 6.9 mmol/L (abnormal fasting blood sugar) | 7.0 mmol/L and above |
| Glycated hemoglobin (HbA1c or A1c) | Between 6.0 and 6.4% | 6.5% and above |
| Blood glucose level 2 hours after drinking a liquid containing 75 g of glucose (oral induced hyperglycemia or OGTT) | Between 7.8 and 11.0 mmol/L (glucose intolerance) | 11.1 mmol/L and above |
| Blood glucose measured at any time of the day | – | 11.1 mmol/L and above, with classic symptoms |
Sometimes a second blood test is necessary to confirm the results obtained.
What is glycated hemoglobin (A1C)?
Glycated hemoglobin (A1C) is a blood test that measures your average blood sugar levels over the past 2 to 3 months. It reflects your blood sugar management and it is used to determine your risk of complications.
You need to have your A1C tested every 3 to 6 months to assess your blood sugar management and adjust your treatment if need be. You don’t need to be fasting for this particular test.