Screening for thyroid disease in children with IDDM

The aim of this study was to evaluate the usefulness of screening for thyroid disease by performing thyroid function tests and measuring thyroid autoantibodies in 371 children and adolescents with insulin-dependent diabetes mellitus (IDDM). We analyzed clinical data and results of serum thyroxine, triiodothyronine uptake, thyroid-stimulating hormone, and antibodies to thyroid microsomal antigen and thyroglobulin. Goiter was noted in 20% of subjects. Thyroid-specific autoantibody was positive in 19% of subjects. Twenty-seven subjects (7%) had thyroid dysfunction. Autoantibody testing identified subjects with thyroid dysfunction with a sensitivity of 50%, a specificity of 84%, a degree of misclassification of 17%, a positive predictive value of 13%, and a negative predictive value of 97%. We recommend that all children and adolescents be screened shortly after diagnosis of IDDM by determination of thyroid-stimulating hormone (measured by high-sensitivity assay) to identify thyroid dysfunction and by testing for antibody to thyroid microsomal antigen to characterize both risk of future thyroid dysfunction and the need for future testing.