Coincident presence of thyro-gastric autoimmunity at onset of type 1 (insulin-dependent) diabetes.

We have determined thyroid microsomal and gastric parietal cell autoantibodies in 972 patients with onset of Type 1 (insulin-dependent) diabetes before age 20 years. In a cross sectional study, the frequencies of these autoantibodies did not change significantly over the ensuing 20 years following diagnosis of diabetes. In a longitudinal study of 424 patients with Type 1 diabetes followed up to 5.3 years, few new patients with thyro-gastric autoantibodies were identified. Whereas the frequencies of these autoantibodies among the diabetic patients were more than fivefold greater than for age, sex and race matched controls, they resembled those seen in the non-diabetic general population (n = 1524) for the over 60 year age group. We conclude that in patients with thyro-gastric autoantibodies and Type 1 diabetes, the onset of autoimmune processes affecting the thyroid, gastric mucosa and pancreatic islets tend to be simultaneous, although the resultant diseases have different natural histories.