The why and how of T1D screening and early detection

Screening and early detection of type 1 diabetes can identify people at risk, sometimes years before symptoms appear. Through blood tests that detect diabetes-related autoantibodies, it’s now possible to monitor and even delay the onset of the condition in some cases. However, early detection also raises questions about emotional impact, access to testing, and what to do with this newfound information.

What does screening for type 1 diabetes involve?

Screening is done through a simple blood test that commonly looks for four main diabetes-related autoantibodies: GAD65, IAA, ZnT8 and islet antigen 2 (IA-2). The presence of one or more of these antibodies suggests that the immune system has started to attack insulin-producing cells. Screening can be done at any age, but research shows that it is most effective when performed between ages 2-4, 6-8 and 10-15.

Who should consider getting screened?

People who have a family history of type 1 diabetes (i.e., a parent, sibling or other close relative with the condition) are at higher risk and should consider being screened. Those who have other autoimmune conditions (e.g., celiac disease or thyroid disorders), are also at higher risk. While screening has traditionally focused on these groups, some countries have begun screening the general population, since most people who develop type 1 diabetes have no family history.

What are the benefits of early detection?

The biggest benefit is knowledge—early detection allows families to prepare, receive education and counselling, and understand what signs and symptoms to look for so they can then seek medical support from their healthcare provider. This can help reduce the risk of experiencing diabetic ketoacidosis (DKA) at diagnosis – a potentially life-threatening condition that can occur when diabetes develops suddenly and goes undiagnosed. Early detection can also make someone eligible for ongoing trials or any approved medication to delay the onset of symptomatic type 1 diabetes.

Are there any downsides or risks to early detection?

The blood tests are very safe, but they can carry emotional and practical challenges. A single positive antibody could be a false positive, however, this is rare if the antibody remains positive over time or if multiple antibodies are positive. Learning that you or your child is at high risk for type 1 diabetes can cause stress and uncertainty too. Families may struggle with knowing that diabetes may develop but not knowing exactly when. Ongoing support and clear information from healthcare providers are key to managing this emotional burden.

What happens if someone tests positive for diabetes-related autoantibodies?

If an autoantibody is detected, the first step is to repeat the test to confirm the result. If only one antibody remains positive, ongoing monitoring may be recommended every six to 12 months for a few years to see if another antibody becomes positive. If two or more antibodies are positive, the risk of developing type 1 diabetes is much higher, and more frequent follow-up is needed. This includes regular monitoring of blood sugars, which may include checking blood sugars occasionally at home (using a glucose meter), having hemoglobin A1C blood tests, doing an oral glucose tolerance test (OGTT) or wearing a continuous glucose monitor (CGM). The frequency and intensity of monitoring often depend on age, with younger children monitored every three to six months and adults being monitored every six to 12 months.

Children who initially test negative for diabetes-related autoantibodies have a low but not zero risk of developing type 1 diabetes, especially if they are tested when they are very young, because these markers can appear later. For children with a family history of type 1 diabetes, rescreening may be recommended, particularly up to about age 15.

Can early detection and intervention change the course of the disease?

Yes. A lot of potential therapies are being investigated to delay, prevent or alter the course of T1D progression. This is one of the missions of TrialNet. Currently, only one medication—teplizumab—has been recently granted Notice of Compliance (market authorization) by Health Canada to delay the onset of type 1 diabetes in people who test positive for multiple antibodies and show early signs of abnormal blood sugars. Delaying the disease can mean postponing the need for insulin injections. Early detection also helps prevent serious complications like DKA at diagnosis. Preventing DKA at diagnosis reduces the risk of complications in the future. There are also many other therapies in development that may further change the course of the disease in the future.

Where can we learn more about screening programs in Canada?

There are two options for accessing autoantibody testing in Canada:

1. Research groups, such as:

• TrialNet: An international research network that offers free risk screening (the “Pathway to Prevention” study) for relatives of people with type 1 diabetes, often identifying risk years before symptoms appear.
• CanScreen T1D: A Canadian research consortium studying how acceptable and feasible a national screening program for type 1 diabetes would be, developed in collaboration with people living with diabetes, families and healthcare providers. Although they are not yet offering screening, the goal is to offer screening to children in the future.

2. Through certain hospitals, programs and private labs. You should talk to your doctor for more information if you are interested.

There is growing recognition that type 1 diabetes doesn’t start suddenly—it develops gradually over time. Identifying risk early allows for education, preparation and, in some cases, interventions that may delay or alter the course of the disease. As access to screening expands, early detection offers hope not only for preventing complications at diagnosis, but for changing the future of type 1 diabetes care.

We’d love your feedback

Your input will help us in the development of future type 1 diabetes educational articles: