1.8.2.0 Thyroid Disease
Recommendations
13.23 Consider testing children with type 1 diabetes for antithyroid peroxidase and antithyroglobulin antibodies soon after the diagnosis. B
13.24 Measure thyroid-stimulating hormone concentrations at diagnosis when clinically stable or soon after glycemic control has been established. If normal, suggest rechecking every 1–2 years or sooner if the patient develops symptoms or signs suggestive of thyroid dysfunction, thyromegaly, an abnormal growth rate, or unexplained glycemic variability. E
Autoimmune thyroid disease is the most common autoimmune disorder associated with diabetes, occurring in 17–30% of patients with type 1 diabetes (74). At the time of diagnosis, about 25% of children with type 1 diabetes have thyroid autoantibodies (75); their presence is predictive of thyroid dysfunction- most commonly hypothyroidism, although hyperthyroidism occurs in ˜0.5% of patients with type 1 diabetes (76,77). For thyroid autoantibodies, a recent study from Sweden indicated antithyroid peroxidase antibodies were more predictive than antithyroglobulin antibodies in multivariate analysis (78). Thyroid function tests may be misleading (euthyroid sick syndrome) if performed at the time of diagnosis owing to the effect of previous hyperglycemia, ketosis or ketoacidosis, weight loss, etc. Therefore, if performed at diagnosis and slightly abnormal, thyroid function tests should be repeated soon after a period of metabolic stability and good glycemic control. Subclinical hypothyroidism may be associated with increased risk of symptomatic hypoglycemia (79) and reduced linear growth rate. Hyperthyroidism alters glucose metabolism and usually causes deterioration of glycemic control.