From the Guidelines
Thyroid antibody testing should be ordered soon after the diagnosis of type 1 diabetes in children and adolescents, as recommended by the 2020 standards of medical care in diabetes 1. This approach is supported by the presence of autoimmune thyroid disease in 17-30% of patients with type 1 diabetes, with approximately 25% of children having thyroid autoantibodies at the time of diagnosis 1. The most commonly ordered antibodies include thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb), with TPOAb being more predictive of thyroid dysfunction in multivariate analysis 1. Key points to consider when ordering thyroid antibody tests include:
- Testing for antithyroid peroxidase and antithyroglobulin antibodies soon after diagnosis of type 1 diabetes in children and adolescents
- Measuring thyroid-stimulating hormone concentrations at diagnosis when clinically stable or soon after glycemic control has been established
- Rechecking thyroid-stimulating hormone concentrations every 1-2 years or sooner if the patient develops symptoms suggestive of thyroid dysfunction, thyromegaly, an abnormal growth rate, or unexplained glycemic variation 1. It is essential to note that the presence of thyroid autoantibodies can predict thyroid dysfunction, particularly hypothyroidism, and may be associated with increased risk of symptomatic hypoglycemia and reduced linear growth rate 1. Therefore, ordering thyroid antibody tests soon after the diagnosis of type 1 diabetes in children and adolescents is crucial for early detection and management of autoimmune thyroid disease, ultimately improving morbidity, mortality, and quality of life outcomes.
From the Research
Indications for Ordering Thyroid Antibodies
- Autoimmune thyroid disease (AITD) diagnosis, which includes conditions such as Hashimoto's thyroiditis and Graves' disease 2
- Evaluation of patients with hypothyroidism or hyperthyroidism to determine the underlying cause 3, 4
- Assessment of patients with autoimmune diseases, such as systemic sclerosis and rheumatoid arthritis, who are at higher risk of developing thyroid autoantibodies 5
- Differential diagnosis of thyrotoxicosis and hyperthyroidism, as well as distinction between various forms of thyroiditis 6
Specific Antibodies to Order
- Thyroid peroxidase antibodies (TPOAb) to identify individuals with a higher risk of progression to hypothyroidism 2, 4
- Thyrotropin receptor antibodies (TRAb) to diagnose Graves' disease and predict response to treatment 2, 6
- Thyroglobulin antibodies (TgAb) to support the diagnosis of autoimmune thyroid disease 2, 5
Clinical Scenarios
- Patients with symptoms of hypothyroidism or hyperthyroidism, such as fatigue, bradycardia, constipation, or cold intolerance 4
- Patients with a history of autoimmune diseases, such as systemic sclerosis or rheumatoid arthritis 5
- Patients with thyrotoxicosis or hyperthyroidism, where distinction between different causes is necessary 6