On the other hand, as seen in Fig. 2c–g, serum concentrations of thyroid autoantibodies (anti-TPO and anti-Tg) in the HT group were apparently higher than those in the Con group (Fig. 2c, d), while no differences in serum T3, T4, or TSH levels (Fig. 2e–g) was detected between groups. Here, TPO is linked to hematocrit.