How to Talk to Your Doctor About Type 1 Screening If You’ve Been Misdiagnosed with Type 2 Diabetes
If you’ve been misdiagnosed with type 2 diabetes—when you should have been diagnosed with type 1 diabetes—you know the frustration.
In 40 percent of adults living with type 1 diabetes, a misdiagnosis of type 2 diabetes can happen.
Type 1 diabetes is most likely misdiagnosed in adults because type 2 diabetes is 20 times more prevalent than type 1 diabetes in adults.
Here are some common reasons why type 1 diabetes might be misdiagnosed:
1. Your doctor may not know that type 1 diabetes can begin in adulthood
Despite more than half of new type 1 diabetes cases occurring in adults—and more than 40 percent after age 30—type 1 diabetes was once considered a childhood condition.
If you started showing signs of diabetes as an adult, your doctor may not know that you could be living with type 1 diabetes.
2. Most people who develop diabetes as adults live with Type 2 diabetes
Adult-onset type 1 diabetes accounts for less than 5% of diabetes cases in adulthood.
If you were diagnosed as an adult, your doctor may have assumed that you were living with type 2 diabetes.
3. Features used by doctors to distinguish Type 1 diabetes from Type 2 diabetes don’t always help
“Classical features of type 1 diabetes” are not always reliable—especially to identify late-onset type 1 diabetes.
For example, a lower body mass index (BMI)—less than 25 kg /m2—is associated with type 1 diabetes, but sometimes BMI is a poor discriminator between type 1 diabetes and type 2 diabetes.
4. Type 1 and Type 2 diabetes have many symptoms in common
Type 1 diabetes and type 2 diabetes share many symptoms, including:
- Extreme thirst
- Frequent urination
- Unexplained weight loss
- Exhaustion
5. Some people have a mix of Type 1 diabetes and Type 2 diabetes features
Because manifestations of type 1 diabetes vary in adults, doctors can mistake it for type 2 diabetes, especially when someone has a mix of risk factors associated with type 1 diabetes and type 2 diabetes, like:
- An older adult with a low or normal BMI.
- A young adult with an elevated BMI.
6. Your doctor may not know that some biomarkers can help distinguish Type 1 diabetes from Type 2 diabetes
When a diagnosis is unclear, biomarkers—like type 1 diabetes autoantibodies and C-peptide—can help distinguish type 1 diabetes and type 2 diabetes.
Your doctor may not be aware of them or have access to these tests.
When Should You and Your Doctor Suspect That You Might Have Type 1 Diabetes?
According to the American Diabetes Association (ADA) guidelines on diagnosis and classification of diabetes, no single feature can help a doctor confirm type 1 diabetes in the clinic.
The JDRF developed a tool which was included in the ADA guidelines—the AABBCC approach to diabetes classification—to help doctors identify features suggestive of type 1 diabetes.
Tell your doctor if you:
- Were diagnosed before age 35.
- Have a family history of type 1 diabetes and/or a personal or family history of other autoimmune diseases (e.g., thyroid disease, celiac disease).
- Have a BMI below 25.
- Have poorly controlled or worsening blood-glucose levels on non-insulin treatments, and/or if you started insulin treatment within three years of being diagnosed.
- Have other medical conditions, including heart or kidney disease.
Some Adults with Type 1 Diabetes Don’t Need Insulin Therapy at Diagnosis—And Not All Doctors Know This
Unlike children with type 1 diabetes, some adults have slowly progressive autoimmune diabetes. They produce insulin at diagnosis, and sometimes don’t need insulin treatment for years.
Latent autoimmune diabetes of adults (LADA) is a form of slowly progressive autoimmune diabetes sometimes considered intermediate between type 1 diabetes and type 2 diabetes.
LADA is often defined as diabetes in people over 35 who tested positive for a type 1 diabetes autoantibody, but have features of type 2 diabetes.
There’s debate about what should be called type 1 diabetes or LADA, but ADA guidelines mention that:
- Slowly losing the ability to produce insulin can happen in adults living with type 1 diabetes or LADA.
- Knowing this can sooner help doctors identify and treat these patients with insulin.
- Testing for autoantibodies can help confirm diagnosis in these patients.
If you didn’t need insulin right away, type 1 diabetes could have been missed.
Ask your doctor about insulin therapy if you were diagnosed with type 2 diabetes and have poorly controlled blood glucose.
What Should You Ask For if You Think You’ve Been Misdiagnosed?
You should talk to your doctor about screening for type 1 diabetes, which means getting tested for type 1 diabetes autoantibodies.
Ask to get tested for autoantibodies if you were diagnosed in the last three years
Type 1 diabetes is an autoimmune condition—the immune system produces autoantibodies that attack the body’s own tissues—but type 2 diabetes is not, so autoantibodies can help confirm type 1 diabetes in earlier stages.
If you’ve been diagnosed with type 2 diabetes but are not responding well to typical treatments for type 2 diabetes—or if you suspect type 1 diabetes for another reason—ask your doctor to get tested for autoantibodies.
- If you have features of type 1 diabetes and test positive, your doctor will likely consider type 1 diabetes.
- If you test negative, it does not rule out a type 1 diabetes diagnosis. Your doctor may order other tests and consider other factors to distinguish between type 1 diabetes and type 2 diabetes.
Ask to get tested for C-peptide if you were diagnosed more than three years ago
If your diabetes type is uncertain more than three years after a diagnosis, the ADA recommends measuring levels of C-peptide, a marker of insulin secretion.
- Levels of C-peptide that stay high—above 600 pmol/L—suggest type 2 diabetes.
- Low C-peptide levels—below 200 pmol/L—can confirm a type 1 diabetes diagnosis because they indicate severe insulin deficiency.
A C-peptide test is only indicated in people receiving insulin treatment, so ask your doctor about it and insulin therapy.
How to Talk to Your Doctor if You Think You’ve Been Misdiagnosed With Type 2 Diabetes
Talking to your doctor can feel intimidating, but it doesn’t have to be.
If your blood glucose is not well controlled, it’s normal to look for the cause—and that may include a misdiagnosis.
Be open about why you’re concerned about type 1 diabetes, and your reasons for wanting to get screened.
A few tips to raise your doctor’s suspicion of type 1 diabetes
Doctors will order autoantibody or C-peptide tests when they have a reason to suspect type 1 diabetes.
When asking your doctor about type 1 diabetes screening, focus on:
- Features suggestive of type 1 diabetes that apply to you.
- The mix of type 1 diabetes and type 2 diabetes features you have—if that applies to you.
- The fact that type 1 diabetes can develop in adults—not just in children.
- Your poorly controlled or worsening blood-glucose levels—if that applies to you.
Remember, not responding well to non-insulin treatments is a reason to suspect type 1 diabetes.
What if your doctor is skeptical?
If your doctor is skeptical about you living with undiagnosed type 1 diabetes or ordering a screening test, you can:
- Gently point out that a type 2 diabetes misdiagnosis is common in adults living with type 1 diabetes.
- Ask if insulin therapy might be right for you.
- Ask your doctor to refer you to an endocrinologist to help determine your diabetes type.
Remember, it never hurts to ask—for help, testing or reassurance—but living with undiagnosed type 1 diabetes and not receiving appropriate treatment could lead to serious complications.
Need Motivation to Have That Talk With Your Doctor?
Read about the inspiring stories of T’ara and Grace, who were both misdiagnosed with type 2 diabetes before their diagnosis was corrected.
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