Getting diagnosed with diabetes is usually straightforward, but some cases are more complex, writes diabetes educator TARA SAVAGE.

We often get asked if type 2 diabetes can ‘turn’ into type 1 diabetes. The simple answer is no. That said, it is possible for people to be misdiagnosed or develop type 1 diabetes after a type 2 diabetes diagnosis.

The misconception that type 2 diabetes can turn into type 1 diabetes often stems from the myth that only people living with type 1 diabetes need insulin. This is not true. In fact, according to NDSS data, up to 25% of people with type 2 diabetes use insulin to manage their blood glucose levels.

To know why type 2 diabetes can’t turn into type 1 diabetes, it is important to understand how each type of diabetes develops. Type 1 diabetes is an autoimmune condition. This means the body has ‘attacked’ itself in some way which then results in a person developing certain signs and symptoms. In the case of type 1 diabetes, the body has ‘attacked’ the beta cells of the pancreas, and these are the cells that make an important hormone called insulin. Without insulin, the body is unable to drive glucose into the cells to provide the cells with energy, and the blood glucose levels keep rising over time.

There is also LADA to consider. Latent autoimmune diabetes in adults is an autoimmune condition just like type 1 diabetes that destroys the beta cells in the pancreas, resulting in no insulin production. It occurs in people above 30 years of age and develops slowly over many months. While LADA is sometimes called type 1.5, essentially it is an autoimmune condition attacking the beta cells of the pancreas and requires insulin replacement, just like type 1 diabetes.

In contrast, type 2 diabetes is not an autoimmune condition. Type 2 diabetes develops when either the insulin produced in the pancreas is not working properly (insulin resistance) or the pancreas is not making enough insulin (but the pancreas is still making some). The cause may be genetic or environmental or a combination of the two. While type 2 diabetes can’t turn into type 1 diabetes, some people are misdiagnosed.

How can you know if you have been misdiagnosed?

• Lifestyle changes like increasing physical activity and eating healthily might have some impact but won’t be enough on their own.
• You may have been prescribed medication, but despite taking the medication regularly as prescribed, your blood glucose levels are still not in the target range.
• Your symptoms are not getting better and may be getting worse. Some medications may have a limited impact on type 1 diabetes but again are not effective. This is because what the body really needs is to replace insulin.

The onset of type 1 symptoms can develop rapidly over a few weeks or sometimes over a few months, especially in the case of LADA. If the blood glucose levels rise to very high levels and the need for insulin is not met, diabetic ketoacidosis (DKA) can occur. This is an emergency that requires immediate hospital treatment.

If you have been misdiagnosed with type 2 diabetes and you actually have type 1 diabetes or LADA, you will find that the management strategies for type 2 won’t lower your blood glucose levels to the target range.

When should I see my GP, and are there any tests that can confirm my diagnosis?

Self-monitoring of blood glucose levels at home is a great way to see if the management of your diabetes is working. If you are seeing blood glucose levels that are consistently above your target, this is the time to check in with your doctor, even if you haven’t noticed any new symptoms. If you are experiencing any symptoms of DKA (including dehydration, vomiting, stomach pain, or an acetone smell on your breath), you should go to hospital or call 000 immediately.

There are blood tests that can confirm a diagnosis of type 1 diabetes. Your GP may order these blood tests or refer you to a diabetes specialist (endocrinologist) for further advice. As type 1 diabetes and LADA are autoimmune conditions, when triggered, the body will produce something called antibodies, and specific type 1 antibodies are measurable in the blood. Your doctor can also test your blood for C-peptide. Low or zero levels can indicate that the beta cells of the pancreas are no longer working to release insulin. Having positive antibodies and low to zero C-peptide, along with persistent high blood glucose levels and signs and symptoms, can help your doctor to diagnose your diabetes correctly.

Your doctor may also ask about your family history of diabetes. There are genetic markers that can indicate a person is more likely to develop an autoimmune condition like type 1 and LADA, and these can be tested for.

What if the picture is still not adding up?

There can be other causes of high blood glucose levels that are not type 1 or 2 diabetes. These include medications, other endocrine conditions, genetic conditions such as MODY, and pancreatic surgery. If things are not quite adding up, it is important to make an appointment to see your doctor. Getting the right diagnosis for you is the key to finding the right management path for your diabetes and keeping you healthy for the future years ahead.