Dear Diabetes: How is type 2 diabetes diagnosed?
Type 2 diabetes, formerly known as “adult-onset diabetes,” is a progressive disease that affects about 90% to 95% of the 29.1 Americans with diabetes. According to the Centers for Disease Control and Prevention (CDC), although it is more often diagnosed in adults between the ages of 45 and 64, more people of all ages are being diagnosed, including older adults. (More than 400,000 adults 65 and older are diagnosed with type 2 diabetes every year.) Type 2 diabetes, although uncommon, increasingly affects children and adolescents.
Type 2 diabetes may be considered a “quiet” disease. The CDC estimates that about 1 in 4 Americans with T2 are not aware they are living with it. People who are undiagnosed in an early stage may not necessarily experience symptoms since blood glucose levels can rise gradually over several years. However, high blood glucose levels over time can damage blood vessels, and some people may not be diagnosed with T2 until they have begun to experience those complications. One way people may find out they are living with T2 is when they seek help for complications such as numbness or tingling, pain or slow-healing sores on their feet or lower legs. Another way one might be diagnosed is after being admitted to the hospital for a heart attack or stroke, and receiving a diagnosis of diabetes.
Diagnosis may occur during a life insurance or other routine physical exam. Fasting blood glucose may be a part of these procedures, and may indicate type 2 diabetes.
Finally, if someone is experiencing symptoms of high blood glucose, such as blurry vision, noticeable fatigue or lack of energy, or extreme thirst and frequent urination, they might seek help from a healthcare provider.
Early detection of type 2 diabetes – earlier lifestyle changes and/or diabetes medications – may lead to better health outcomes. Getting screened for type 2 diabetes starts with knowing your risk. There are risk assessments readily available, such as the one provided by the American Diabetes Association. If you have an elevated risk for type 2 diabetes, it may be best to get checked yearly.
The blood tests used for diagnosing type 2 diabetes require blood from a vein, and this is performed in a clinic or lab. The blood tests are: a fasting blood glucose, an oral glucose tolerance test, or a hemoglobin A1C. If one of these shows positive results for diabetes, the current guidelines recommend that the same test be repeated on a different day in order to confirm a diagnosis.
• An oral glucose tolerance test is also performed first thing in the morning after an 8-hour fast. It includes drinking a glucose-water mixture and having blood drawn 2 hours later. A result equal to or above 200 mg/dL is positive for diabetes.
One of these blood tests, if taken on their own, may either miss some individuals with diabetes, or misdiagnose others who don’t have diabetes. Therefore, the recommendation is to repeat testing (with the same test) on a different day.
Talk to your healthcare provider if you have any questions or concerns about diabetes, or would like to understand the risk factors for type 2 diabetes.
Jane K. Dickinson is a nurse and certified diabetes educator who has lived with type 1 diabetes since 1975. Jane lives in Steamboat Springs, Colorado, where she provides diabetes education to community members and healthcare providers. She is currently the program coordinator and faculty for the Diabetes Education and Management Masters Program at Teachers College Columbia University. Jane has published two books: People With Diabetes Can Eat Anything and Diabetes Karma. Jane writes about everyday topics and how they relate to diabetes on her blog at www.janekdickinson.com/ In her spare time, Jane loves to walk, travel, listen to music, watch movies, and spend time with her husband and two children.
© 2014 The DX: The Diabetes Experience