Omentin-1 Levels in Hypothyroid Patients with Autoimmune Thyroiditis.

Objective: To determine Omentin-1 in hypothyroid patients with autoimmune thyroiditis compared to controls.

Study design: Observational study. Place and Duration of the Study: Department of Internal Medicine and Endocrinology, University of Health Sciences, Antalya Training and Research Hospital, Turkiye, between August 2017 and March 2020.

Methodology: The study included 63 newly diagnosed hypothyroid patients with autoimmune thyroiditis and 40 healthy volunteers. Body mass index, fasting blood glucose, homeostasis model assessment for insulin resistance, lipid profile, thyroid function tests, thyroid autoantibodies, and omentin-1 levels were determined before and after treatment with levothyroxine sodium in all participants.

Results: Omentin-1 was significantly higher in the control subjects [15.05 (12.12-18.06) ng/ml] than in the hypothyroid patients with autoimmune thyroiditis [3.04 (2.39-3.76) ng/ml, p<0.001]. There was no significant difference in omentin-1 level in patients who achieved euthyroidism by treatment (p=0.26). In correlation analysis, serum omentin-1 level was found to correlate negatively with thyroid-stimulating hormone (r=-0.27, p=0.006), anti-thyroid peroxidase (r=-0.32, p=0.001), and anti-thyroglobulin antibodies (r=-0.26, p=0.007), whereas it correlated positively with free triiodothyronine (r=0.22, p=0.021) and free thyroxine (r=0.24, p=0.012).

Conclusion: Lower omentin-1 levels in hypothyroid patients with autoimmune thyroiditis and its negative correlation with thyroid-stimulating hormone suggest that omentin-1 may play some role in hypothyroidism and autoimmune thyroiditis.

Key words: Hypothyroidism, Chronic autoimmune thyroiditis, Omentin-1.