HASHIMOTOS-THYROIDITIS AND INSULIN-DEPENDENT DIABETES-MELLITUS - DIFFERENCES AMONG INDIVIDUALS WITH AND WITHOUT ABNORMAL THYROID-FUNCTION

Insulin-dependent diabetes mellitus probands from the Familial Autoimm une and Diabetes Study were evaluated for autoimmune thyroid disease ( n = 265). The prevalence of Hashimoto's thyroiditis was 26.6%; 42.0% o f these individuals were euthyroid, and 58.0% were hypothyroid. There was a female predominance among hypothyroid and euthyroid Hashimoto's cases compared to those with no thyroid disease (75% vs. 72.4% vs. 41. 6%; P < 0.001). Insulin-dependent diabetes mellitus patients with hypo thyroid Hashimoto's thyroiditis were more likely to report another aut oimmune disease compared to euthyroid Hashimoto's patients or individu als with no thyroid disease (30.8% vs. 17.2% us. 13.9%; P < 0.01). Sex -specific analysis revealed that this difference was significant for m en but not for women. Both euthyroid and hypothyroid Hashimoto's cases were more likely to have a family history of the disease (66.7% vs. 6 9.2% vs. 47.7%; P < 0.05). No differences were observed in the prevale nce of DQA10501-DQB1*0201 or DQA1*0301-DQB1*0302 across the three gro ups. Body mass index, lipid levels, glycemic control, and diabetes com plications were also similar. However, euthyroid Hashimoto's women wer e more likely to report spontaneous abortions than those with hypothyr oid Hashimoto's thyroiditis or no thyroid disease (23.8% vs. 61.5% vs. 29.1%; P < 0.05). These data suggest that gender-specific risk factor s may be primary determinants of Hashimoto's thyroiditis and other aut oimmune diseases among women. However, disease-specific determinants m ay also increase susceptibility to other autoimmune diseases.