From the Guidelines
Children with new-onset Diabetes Mellitus Type 1 (DM1) should have their thyroid function assessed.
Recommended Labs
- Thyroid-stimulating hormone (TSH) concentrations should be measured at diagnosis when clinically stable or soon after optimizing glycemia 1
- Antithyroid peroxidase and antithyroglobulin antibodies should be considered for testing soon after diagnosis 1
Rationale
The presence of thyroid autoantibodies is predictive of thyroid dysfunction, most commonly hypothyroidism, although hyperthyroidism can also occur 1.
Follow-up
If TSH concentrations are normal, they should be rechecked every 1–2 years or sooner if the patient has positive thyroid antibodies or develops symptoms or signs suggestive of thyroid dysfunction, thyromegaly, an abnormal growth rate, or unexplained glycemic variability 1.
Additional Considerations
Thyroid function tests may be misleading if performed at the time of diagnosis due to the effect of previous hyperglycemia, ketosis, or ketoacidosis, and should be repeated after a period of metabolic stability and good glycemic control 1.
From the Research
Laboratory Tests for New-Onset Diabetes Mellitus Type 1 (DM1)
The following laboratory tests are recommended for a child with new-onset DM1:
- Hemoglobin A1c (HbA1c) test to confirm the diagnosis of DM1 2
- Blood tests for islet autoantibodies, including:
- Insulin autoantibodies (IAA)
- Glutamic acid decarboxylase autoantibodies (GADA)
- Insulinoma-associated protein 2 autoantibodies (IA-2A)
- Zinc transporter 8 autoantibodies (ZnT8A) 3
- Blood glucose tests to monitor glucose levels 4
Diagnostic Criteria
The diagnostic criteria for DM1 include:
- HbA1c values greater than 6.35% 2
- Presence of islet autoantibodies, such as GADA, IA-2A, and ZnT8A 3
- Symptoms of hyperglycemia, such as polyuria and polydipsia 2
Monitoring and Management
Regular monitoring of glucose levels and HbA1c is essential for managing DM1 in children. The use of insulin pumps and continuous glucose monitors (CGM) may help improve glycemic control in children with new-onset DM1 5