The characteristics of children diagnosed with type 1 diabetes before and after the age of six have been investigated in a new study.

Researchers looked at the differences in the presentation and cause of autoantibodies and genotypes in children diagnosed with the condition.

Studies by The Environmental Determinants of Diabetes in the Young (TEDDY) are adding to an increasing body of evidence suggesting that type 1 diabetes is not a single disease. They suggest that autoimmune diabetes varies amongst children who are at high risk due to their genetic makeup.

These studies advance what is known about autoantibodies relating to type 1 diabetes and can aid in foreseeing which genetically high-risk children are most likely to develop type 1 diabetes as they grow.

For people with type 1 diabetes, a misdirected immune response attacks and wipes out beta cells in the pancreas that produce insulin. The four autoantibodies that are associated with attacking these beta cells (GADA, IA, IA2-2A, and ZnT8A) are the most reliable in indicating that the person may develop type 1 diabetes. Nevertheless, not all children with any of these indicators are guaranteed to get type 1 diabetes.

A TEDDY study evaluated the features of type 1 diabetes in children who were diagnosed before six-years-old, compared to those diagnosed after six-years-old.

Lead author Dr Jeffrey Krischer, a Distinguished University Health Professor and co-chair for the National Institutes of Health-funded TEDDY consortium, said: “Our results underscore the importance of taking into account the age at development of multiple autoantibodies when evaluating risk factors for progression to a diabetes diagnosis. When the changing picture of autoantibody presentation is considered, it appears type 1 diabetes at an early age is a more aggressive form of the disease.”

The research involved 8,502 participating children who were at high-risk of getting type 1 diabetes. Researchers tracked the children from their birth to an average of nine-years-old. Overall, 328 of these children developed from a presymptomatic stage, where autoantibodies could be detected in their blood, to symptomatic type 1 diabetes.

Of the 328 children, half were diagnosed with type 1 diabetes before six-years-old, and the other half between six- and 12-years-old. Researchers then examined any differences between the age groups to assess if the forms of type 1 diabetes were the same.

The results show that children who were diagnosed with type 1 diabetes between six and 12 were prone to have had the GAD autoantibodies, yet IA autoantibodies were more likely to be found in children under six developing type 1 diabetes.

They also found that if more than one autoantibody were detected in children under six, type 1 diabetes was likely to progress more slowly.

The noteworthy link to which country the children were from had less impact for those over six.

The connection between the children’s genetic makeup and higher risk of type 1 diabetes was more substantial for those over six. Nevertheless, when the children over six presented more than one autoantibody, their family history had little-to-no influence over developing type 1 diabetes.

Dr Krischer explained: “Much of the observed differences in the relationship between genes and environmental exposures can be explained by the age at appearance of autoantibodies. That is important, because it means factors linked with diabetes risk need to be conditioned on age to be properly understood. There may be different environmental exposures occurring at different ages that trigger autoimmunity, or the same environmental trigger may act differently at different ages.”

The study was published in Diabetologia.

Get our free newsletters

Stay up to date with the latest news, research and breakthroughs.