High prevalence of thyroid autoantibodies at diagnosis of insulin-dependent diabetes mellitus in Swedish children.

The prevalence of thyroglobulin autoantibodies and that of thyroid peroxidase autoantibodies were studied in serum samples from 52 children with insulin-dependent diabetes mellitus, sampled at diagnosis and before the start of insulin treatment, with 386 non-diabetic schoolchildren (11 to 13 years of age) serving as control subjects. Using exactly the same sensitive solid-phase immunosorbent radioassay for both thyroid autoantibodies, with comparable sensitivity, we found the prevalences of both autoantibodies to be higher in the insulin-dependent diabetes mellitus group than in the control group, the difference being most pronounced for thyroid peroxidase autoantibodies. Thyroglobulin autoantibodies were positive in 33% of the diabetics versus 14% in the control group (p = 0.002), and thyroid peroxidase autoantibodies were positive in 38% versus 6% (p = 0.0001). The high prevalence of thyroid autoantibodies already at diagnosis stresses the importance of early screening for thyroid disease in patients with insulin-dependent diabetes mellitus.