Abstract
Previous studies have demonstrated a higher prevalence of thyroid antibodies in diabetics than in age and sex matched controls. Coexistence of Hashimoto thyroiditis and diabetes mellitus has also been noted by several investigators. However, the prevalence of Hashimoto thyroiditis in juvenile-onset and adult-onset diabetics has not yet been reported in detail.
In the present study, 36 patients with juvenile-onset diabetes mellitus and 255 patients with adult-onset diabetes were examined by careful palpation to determine whether or not they had goiters. The occurrence of thyroid antibodies was also investigated in sera from all patients, using the thyroglobulin-coated and microsome-coated tanned red cell hemagglutination tests as prepared by Fuji Zoki Co., Tokyo. Needle biopsy of the thyroid was performed in some cases of goiter, in order to confirm the diagnosis of Hashimoto thyroiditis.
Of the 36 patients with juvenile-onset diabetics, 4 (11.1%) had diffuse goiter, whereas theadult-onset diabetics with goiter amounted to 35 cases (13.7%). The juvenile-onset diabetics showed an increased frequency of goiter, compared to that for young subjects under 20 yr old previously reported. On the other hand, the prevalence of goiter in adult-onset diabetics was similar to that (11.3%) in 150 patients with no evidence of metabolic or endocrine disease who were studied as “hospital controls”.
The adult-onset diabetics with goiter were predominantly women and their ages were distributed mainly from the 4th to 5th decade. The sex distribution of these patients was thus similar to that for patients with Hashimoto thyroiditis. Moreover, 12 (34.3%) of 35 cases with goiter were found to be positive for antimicrosomal antibody and diagnosis of Hashimoto thyroiditis was established in 13 cases (37.1%). In contrast, the prevalence of thyroid antibodies in adult-onset diabetics with no evidence of goiter was not significantly different from that reported previously for normal subjects. It appears therefore that the occurrence of thyroid antibodies in adult-onset diabetics is strongly indicative of an association of coexistent Hashimoto thyroiditis.
Four juvenile-onset diabetics with goiter were diagnosed as having typical Hashimoto thyroiditis on the basis of histological findings for specimens obtained by thyroid needle biopsy. The prevalence of Hashimoto thyroiditis was approximately 11.1% in patients with juvenile-onset diabetes mellitus. Thus, a high prevalence of Hashimoto thyroiditis was evident in juvenile-onset diabetics compared to that reported previously in young subjects under 20 yr old. The juvenile diabetics with Hashimoto thyroiditis were characterized by having mainly insulin-dependent diabetes and by showing extremely high titers of antimicrosomal antibodies. Moreover, the family histories of these patients revealed that at least one close relative had both diabetes mellitus and goiter.
