Endocrine Abstracts

Introduction and aims: The role of screening for thyroid disease in diabetes (DM) remains controversial. We assessed the prevalence of thyroid dysfunction on first screening in a population of patients with diabetes who previously had thyroid function tests (TFT) only on clinical suspicion.

Methods: TFT and thyroid peroxidase antibodies (TPO) were measured in 236 consecutive patients with DM (mean age 59±13 years, type1 16%, type2 84%, female 48%).

Results: In the entire group, 27 (11.4%) had thyroid abnormalities. 20(8.5%) had known hypothyroidism (16 female, 19 type2 DM, 10 TPO positive), 2(1%) hyperthyroidism (1 female, both type2 DM and TPO negative) and 11% were TPO positive. One patient had lithium-induced hypothyroidism. In the remaining 214 patients, 2(1%) had subclinical hypothyroidism (1 female, 1 type1 DM, 1 TPO positive), 2(1%) subclinical hyperthyroidism (1 female, 2 type2 DM, 1 TPO positive), 1(0.5%) hyperthyroidism (female, type2 DM, TPO negative), while none had hypothyroidism (low FT4 with high TSH). 208 (97%) had normal TFT.

Conclusion: Substantial prevalence of thyroid abnormalities was noted in patients with diabetes. High prevalence of hypothyroidism in type2 diabetes relative to type1 diabetes was due to the high age of the population. However, infrequent detection of new patients with abnormal TFT cannot justify the cost of routine screening of all patients. We recommend TFT only when thyroid disease is suspected clinically.