With what condition is the TBGUCK level typically decreased?

The TBG (Thyroxine-Binding Globulin) level is typically decreased in the condition of hypothyroidism. In hypothyroidism, there is a deficiency of thyroid hormones, which leads to a reduced production of TBG by the liver. Since TBG is responsible for binding thyroid hormones in the bloodstream, a decrease in TBG directly correlates with lower levels of circulating thyroid hormones.

As a result, individuals with hypothyroidism may have lower serum T3 and T4 levels, which can affect metabolism and overall health. This relationship is significant because one of the ways to assess thyroid function and diagnose related disorders is by measuring both free and total thyroid hormone levels along with TBG levels. In contrast, conditions like hyperthyroidism often result in increased TBG levels due to the higher demand for transport proteins in the presence of elevated thyroid hormones.