"PREVALENCE OF AUTOANTIBODIES TO THYROID PEROXIDASE AND AUTOIMMUNE THYROID DISEASE IN TYPE I DIABETES MELLITUS"

Abstract

Type I diabetes mellitus (DM) is frequently associated with autoimmune thyroid disease (ATD). Association of ATD and type I DM has been described with varying frequencies but there is still debate about the situation in the Iranian population. We investigated the prevalence of anti thyroid peroxidase (anti-TPO) antibodies and ATD in children and adolescents with type I DM. A total of 145 patients with type I DM were participated in this study. They were screened for anti-TPO antibodies and TSH levels. Signs and symptoms of hypothyroidism and hyperthyroidism and the presence of goiter were sought. A group of 50 healthy unrelated girls and boys aged 11-16 years served as controls. Anti-TPO antibodies were found in 34 (23.4%) diabetic patients and 1 subject (2%) in the control group (P<0.001). Frequency of anti TPO antibodies was significantly higher in girls than boys (P<0.05). We failed to show any significant correlation between thyroid autoimmunity and duration of DM. We found that younger patients at diagnosis are more likely to be anti-TPO negative (P<0.001). Out of 145 diabetic patients, 32 (22%) had visible goiter. Subclinical hypothyroidism, hypothyroidism and thyrotoxicosis occurred in 1, 9 and 1 patients, respectively. Visible goiter was found in 2 subjects (4%) of the control group, but all of them were euthyroid. In conclusion, the evaluation of thyroid autoimmunity in type I diabetic patients may improve the diagnosis of thyroid disease in early stages. Yearly examination of anti-TPO antibodies allows identifying diabetic patients with thyroid autoimmunity.