Sex Hormone Inhibitory Globulin (SHBG)

SHBG (sex hormone-binding globulin) is a plasma protein that specifically binds to 3 sex hormones: estrogen, dihydrotestosterone and testosterone. It is synthesized by liver cells and released into the blood, where it has a half-life of about 7 days. Its secretion is controlled by circulating androgen and estradiol levels.

SHBG concentrations affect both the bioavailability of sex steroids in tissue and the balance of estrogen-androgens.

Elevated levels of androgens and androgenic progestins inhibit SHBG synthesis, while elevated levels of estradiol and thyroid hormones stimulate SHBG synthesis.

Thus, low concentration of SHBG occurs in the following situations: hirsutism, virilization, acne vulgaris, polycystic ovary syndrome, hyperandrogenism, obesity, hypothyroidism, acromegaly, Cushing's syndrome, hyperprolactinemia, androgen-secreting ovarian tumors.

On the other hand, the increased concentration of SHBG is found in: hypogonadism, gynecomastia, androgen deficiency, decreased sensitivity to androgens, hyperthyroidism, liver cirrhosis, anorexia nervosa.

When should I get tested for sex hormone-binding globulin?

The examination is mainly recommended and prescribed by an obstetrician-gynecologist or endocrinologist.

The SHBG (Sex Hormone Binding Globuline) test is used to monitor sex hormones and antiandrogen therapy, to diagnose puberty, to diagnose and monitor patients with anorexia nervosa, and to diagnose thyrotoxicosis. In thyrotoxicosis, it is used as a tissue marker for increased levels of thyroid hormones.

This study is also useful in diagnosing and monitoring the risk of developing insulin resistance, cardiovascular disease, and type 2 diabetes, especially in women. It is also used to measure free testosterone levels in men.

How to prepare for the test?

Testing is preferred Fasting.

Research material

Venous blood

Possible interpretation of the results

Many conditions characterized by low or moderately high androgen levels are associated with low levels of SHBG - for example, polycystic ovary syndrome. Most of these women also suffer from insulin resistance and obesity. In this case, in addition to the SHBG study, other tests are usually performed to fully assess the overall condition.

The test is also used to evaluate anti-androgen or estrogen therapy. In this case, an increase in the level indicates successful therapy, and in the case of androgen therapy, a decrease in the level of SHBG, which binds to sex hormones, is a sign of correct and successful treatment.

SHBG levels are high in patients with neurotic anorexia as well as in thyroid hormone excess.

Low levels of SHBG may be a precursor to the progression of insulin resistance, cardiovascular complications, and type 2 diabetes, especially in women who have gestational diabetes (during pregnancy).

Elevated SHBG level:

• Primary, secondary hypogonadism in men;
• Androgen hypersensitivity syndrome;
• Hyperestrogenia;
• Hyperthyroidism;
• Andropause in men;
• Liver disease, viral hepatitis

Decreased SHBG level:

• Increase androgen synthesis;
• Taking androgens;
• Insulin resistance;
• Hypothyroidism;
• Acromegaly;
• Cushing's disease / syndrome;
• Hyperprolactinemia;
• Polycystic ovary syndrome;
• Adrenogenital syndrome;
• Peri- and menopause in women;
• Nephrotic syndrome;
• Systemic collagenosis.