The study was conducted at The Environmental Determinants of Diabetes in the Young (TEDDY).
Lead researcher Åke Lernmark, MD, PhD, of Lund University said: “In the TEDDY study, we have found that autoantibodies often appear during the first few years of life.”
Researchers enrolled and followed 8,600 children from Sweden, the United States, Germany and Finland who are extremely likely to develop hereditary type 1 diabetes, which means they have the HLA-DR high-risk genotypes (DR3/4, DR4/4, DR4/8 and DR3/3).
The findings were published in journal Diabetologia.
According to the study, there are three ways of predicting the development of type 1 diabetes.
Participants in the study were enrolled as infants and had quarterly standardized autoantibody monitoring for the first 4 years of life, and semi-annually later.
The researchers found autoantibodies in 549 of 8,503 (6.5%) children during 34,091 person-years of follow-up. As much as 44% only had islet autoantibodies against insulin (IAA), with the incidence peaking within the first year of life and declining during the next 5 years. About 38% only had glutamic acid decarboxylase autoantibodies (GADA), with incidence only increasing until age 2 years and then remaining constant. About 14% of those with autoantibodies had both IAA and GADA, with incidence peaking around age 2 to 3 years.
Hereditary risk appeared to determine which autoantibody was found, with GADA only being more common than IAA only in HLA-DR3 children but less common in HLA-DR4/8 children. Nevertheless, what causes the immune system to attack the body’s own insulin cells remains unknown, although viral infection has been suggested as a potential trigger.
“It is possible that there are two different diseases involved. Perhaps one virus triggers the autoantibodies against insulin and another one the autoantibodies against GAD65,” Dr. Lernmark said.