Endocrine Abstracts

Background: Subclinical hypothyroidism (SH) is a frequent clinical condition with a prevalence of 3–15% in general population. It is defined by elevated TSH levels with normal thyroid hormones [free thyroxine (FT4) and free triiodothyronine (FT3)]. Similar to prolactin, high TSH levels may be caused by macroTSH, a large molecular sized TSH with a low bioactivity. The aim of the study was to assess the prevalence of macroTSH in patients with subclinical hypothyroidism....