What is Androstenedione?

Also Known As: AD

Androstenedione is an androgen, one of several “male” sex hormones that are responsible for the onset of sexual differentiation in males and females and the development of secondary male physical characteristics such as a deep voice and facial hair. Though it is considered to be a “male” sex hormone, it is present in the blood of both men and women and is a precursor that can be converted by the body into more potent androgens, such as testosterone, or converted into the female hormone estrogen. This test measures the amount of androstenedione in the blood.

Androstenedione is produced by the ovaries in women, the testicles in men, and by the adrenal glands in both.

• The pituitary hormone LH stimulates the release of androstenedione by the ovaries and testicles.
• The pituitary hormone adrenocorticotropic hormone (ACTH) stimulates the release of androstenedione by the adrenal glands.

The level of androstenedione in the blood will vary during the day in a “diurnal pattern,” and it will vary during a woman’s menstrual cycle. Because of its origins, androstenedione can be useful as a marker of adrenal gland function, of androgen production, and of function of the ovaries or testicles. An androstenedione test is often performed after results of other tests, such as testosterone or 17-hydroxyprogesterone, are found to be abnormal.

An excess level of androstenedione and other androgens can cause children to have sex organs that are not clearly male or female (ambiguous external genitalia), excess body hair (hirsutism), and abnormal menstrual periods in girls and precocious (early) puberty in girls and boys.

Adrenal tumors, ACTH-producing tumors, and adrenal hyperplasia can lead to the overproduction of androstenedione. Women with polycystic ovary syndrome (PCOS) may have higher levels of androstenedione as well. While elevated levels may not be noticed in adult men, they can lead to noticeable male physical characteristics (virilization) and a lack of monthly menstrual periods (amenorrhea) in females.

How is it used?

Androstenedione testing is used to evaluate the function of the adrenal gland and the ovaries or the testicles as well as the production of hormones related to the development of male sex organs and physical characteristics (androgens). It is most commonly used to determine the cause of symptoms of excess androgens in a woman who has an elevated testosterone level, along with a few other laboratory tests for this purpose.

An androstenedione level may be used to:

• Evaluate adrenal gland function and to distinguish between androgen-secreting conditions that are caused by the adrenal glands from those that originate in the ovaries or testicles, if results of DHEAS and testosterone testing are abnormal
• Help diagnose tumors in the outer layer (cortex) of the adrenal gland or tumors outside of the adrenal gland that secretes ACTH (ectopic) and separate these conditions from ovarian or testicular tumors and cancers
• Diagnose congenital adrenal hyperplasia (CAH) and monitor CAH treatment, in addition to tests for testosterone and 17-hydroxyprogesterone, for example
• Help diagnose polycystic ovarian syndrome (PCOS) and help rule out other causes of infertility, no monthly menstrual periods (amenorrhea), and excess body and facial hair (hirsutism) in women who have abnormal results on tests for DHEAS, testosterone, and other hormones such as FSH, LH, prolactin, and estrogen
• Investigate and diagnose the cause of male physical characteristics (virilization) in young girls and early (precocious) puberty in young boys
• Help determine the cause of delayed puberty and investigate suspected ovarian or testicular failure