The hepcidin concentration decreases in hypothyroid patients with Hashimoto's thyroiditis following restoration of euthyroidism.

The purpose of the study was to measure the hepcidin concentration and evaluate Fe homeostasis indices in a prospective study on patients with newly diagnosed hypothyroidism in the course of Hashimoto's thyroiditis (HT) and following successful therapy. The prospective observational study consisted of 34 patients. The clinical evaluation and laboratory tests were performed at diagnosis (T0) and after restoration of euthyreosis 12 weeks later (T1). The median level of hepcidin was significantly lower (p = 0.002) after recovery (7.7 [6.2-13.0] ng/mL) than that before treatment (17.4 [7.6-20.4] ng/mL), while creatinine (p = 0.011) and GFR (p < 0.001) significantly improved after euthyroidism was achieved. A positive correlation was observed between hepcidin and fT3 (p = 0.033, r = 0.465) at T0. In the females, the level of hepcidin positively correlated with ferritin concentration before (p < 0.001, r = 0.928) and after treatment (p < 0.001, r = 0.835). A statistically significant difference was observed in RDW-CV (red blood cell distribution width - coefficient of variation) between the hypothyroid and euthyroid states. In conclusion, a decrease in hepcidin concentration during the transition from the hypothyroid state to euthyroidism in patients with HT is associated with the observed dynamics in iron homeostasis, mainly reflected by improvement in RDW-CV and significant correlations between ferritin and hepcidin as well as between hepcidin and fT3.