The diagnosis of type 1 diabetes mainly depends on the level of blood sugar in the blood. There are currently 4 ways to diagnose diabetes.
- Fasting Blood Sugar: This is the most common test that is used for diagnosing diabetes as it is a simple and convenient test. In this test, blood sugar is taken after a fast of 8 hours. Fasting means that you should not eat or drink (except water) for 8 hours. This is usually done in the morning before eating breakfast. A normal fasting blood sugar is a level less than 100 mg/dL. A fasting blood sugar of 126 mg/dL or more, satisfies a diagnosis of type 1 Diabetes Mellitus.
- Oral glucose tolerance test:This test checks the body’s capacity to lower the blood sugar after taking a concentrated amount of glucose. This also needs fasting for 8 hours prior to the test. After fasting blood sugar is taken, 75 grams of glucose dissolved in water is ingested. Blood is drawn again after the 1st and 2nd hour. If the blood sugar on the 2nd hour is more than or equal to 200mg/dl, diabetes is considered.
- Glycosylated Hemoglobin (Hemoglobin A1C or Hgb A1C) Level: This determines the level of control of blood sugar in the last 2 to 3 months. It checks the level of sugar that has attached to the red blood cell. A level of 6.5% or greater is diagnostic of diabetes.
- Random Blood Sugar of at least 200 mg/dl with signs and symptoms of diabetes: This test has the lowest reliability and should be confirmed with another test in diagnosing diabetes.
The diagnosis of diabetes should only be done by a certified medical practitioner. Your doctor might repeat the test to make sure of the diagnosis.
Once the diagnosis of diabetes is established, the next step is to figure out if it is type I or type II based on your symptoms and laboratory studies although there is no set criteria to differentiate these 2 types.
The following are the general differences between type I and type 2 diabetes:
- Type 1 diabetes often present before the child is 10 years of age. On the other hand, type 2 diabetes generally presents after the onset of puberty.
- More than 75-90% of those with type 2 diabetes have an affected relative whereas only 10% of patients with type 1 diabetes have a relative with the diabetes.
- Patients with type 2 diabetes are generally overweight or obese. In contrast, children with type 1 diabetes are usually not obese and may even have recent history of weight loss.
- Some patients may have mixed features where it is hard to differentiate between type 1 and type 2 diabetes. Your health care provider may do blood tests including insulin level, a protein called C-peptide level, or antibodies to pancreatic cells, etc. to see if you have type 1 or type 2 diabetes.
1. Simmons KM, Michels AW. Type 1 diabetes: A predictable disease. World J Diabetes. 2015 Apr 15;6(3):380-90.