What does it mean if sex hormone-binding globulin (SHBG) levels are elevated?

Generally, elevated sex hormone-binding globulin (SHBG) refers to a concentration of SHBG in the blood that exceeds the normal range. A detailed explanation is as follows:

Sex hormone-binding globulin is a protein responsible for transporting sex hormones. Its primary function is to bind to sex hormones, such as testosterone and estradiol, thereby regulating the biological activity and metabolism of these hormones. When SHBG levels are elevated, more sex hormones may be bound, leading to a relative decrease in the levels of free, biologically active sex hormones in the blood. This may affect the physiological functions of sex hormones, including the development and maintenance of sexual characteristics and reproductive functions.

Increased SHBG levels can be caused by various factors. In women, SHBG levels may rise during pregnancy or with the use of estrogen-containing medications, as estrogen stimulates the liver to produce more SHBG. Certain medical conditions, such as hyperthyroidism, can also elevate SHBG levels, as excessive secretion of thyroid hormones affects the synthesis and metabolism of SHBG in the liver.

If elevated SHBG is detected, it is recommended to perform additional tests, such as thyroid function tests, liver function tests, and a six-item sex hormone panel, to identify the underlying cause. Treatment should be carried out under the guidance of a physician.