Aims/hypothesis
Thyroid autoimmunity clusters with other endocrine and non-endocrine forms of autoimmunity. The aim of this study was to determine
the chronological appearance of thyroid autoantibodies in relation to other forms of autoimmunity in at-risk children.
Methods
The BABYDIAB study follows children of parents with type 1 diabetes. Children born in Germany between 1989 and 2000 were recruited
at birth and followed up at 9 months and at 2, 5, 8, 11, 14 and 17 years. Antibodies to thyroid peroxidase were measured in
samples taken at the last study visit in 1,489 children and in all previous samples in children who tested positive. Islet
antibodies and antibodies to 21-hydroxylase and transglutaminase were also measured in all children. Median follow-up was
8 years.
Results
The cumulative risk for developing antibodies to thyroid peroxidase was 20.3% (95% CI 12.3–28.3) by age 14 years. The risk
was increased in girls (adjusted HR 2.0; 95% CI 1.2–3.4; p = 0.008), in children who had multiple first-degree family history of type 1 diabetes (adjusted HR 3.3; 95% CI 1.4–8.0; p = 0.006) and in children who also had antibodies to GAD (adjusted HR 3.0; 95% CI 1.5–5.9; p = 0.001). Thyroid peroxidase antibody appearance was most common from age 8 years and was often the last autoantibody to
develop in children with other autoantibodies.
Conclusions/interpretation
Among children of patients with type 1 diabetes, the appearance of thyroid autoantibodies is frequent, is not synchronous
to the appearance of other autoantibodies and is most common in late childhood and adolescence.
Keywords Islet autoantibodies - Thyroid autoimmunity - Type 1 diabetes