Endocrine Abstracts

Aim: Increased thyroid volume and thyroid dysfunction (TD) in diabetics have been reported. The aim of this study is to investigate the prevalence of thyroid disorders in patients with type 2 diabetes mellitus in formerly iodine deficient area.

Methods: We included 131 (73 females and 58 males) diabetics without a history of previous thyroid disease and symptoms. The demographic, medical and clinical data, laboratory results (fasting plasma glucose (FPG), HbA1c, lipid profile, TSH, free thyroxine (fT₄), and free triiodothyronine (FT₃)) were recorded. The result of thyroid function was classified as subclinical hyperthyroidism (Sc-hyper) (TSH ≤0.5 mIU/l, FT₄ and FT₃: normal), euthyroidism (TSH: 0.5–4, FT₄ and FT₃: normal), and subclinical hypothyroidism (Sc-hypo) (TSH: 4.1–9.9, FT₄ and FT₃: normal). All participants were evaluated by thyroid ultrasonography (US) and thyroid volume (TV) were calculated by standard formula.

Results: There is a significant difference between females and males with respect to age, smoking habit, and BMI. No significant differences were found between two groups with respect to diabetes duration, FPG, HbA1c, lipids levels, and thyroid function. Sc-hyper, euthyroidism, and sc-hypo were detected in 15 (11.4%), 107 (81.7%), and 9 (6.9%) patients respectively. US findings except TV were similar in two groups. Although, TV was higher in males than females, the diameter of dominant nodule was not different. In all patients, the frequencies of normal US, multinodular goitre (MNG), nodular goitre (NG), diffuse goitre (DG), and thyroiditis with or without nodule were 24 (18.3%), 51 (38.9%), 27 (20.6%), 10 (7.6%), and 19 (14.6%) respectively.

Conclusion: The most common thyroid disorder in diabetics is hypothyroidism. Although, the prevalence of thyroid dysfunction in our patients is concordant with previous results, sc-hyper is more prevalent than sc-hypo. According to our results, 81.7% of diabetics had thyroid gland abnormality by US. In light of these results, all diabetics should be evaluated for thyroid disorders.