Androstenedione

Overview

Androstenedione is a steroidal hormone produced in both males and females. As described in the document, it is secreted mainly by the adrenal glands and also by the testes in males and the ovaries in females. The functions primarily as an endogenous prohormone, acting as a common precursor for the synthesis of androgen and estrogen sex hormones. It plays an intermediate role in steroidogenesis and is derived from cholesterol through specific enzymatic pathways.

Its production is regulated by pituitary hormones. Adrenocorticotropic hormone (ACTH) stimulates its release from the adrenal glands, while luteinizing hormone (LH) stimulates secretion from the ovaries and testicles. Once produced, it can be converted into testosterone via the enzyme 17β-hydroxysteroid dehydrogenase or into estrone via aromatase. Because of this central role, measurement of it is valuable in assessing disorders related to androgen excess or deficiency.

Symptoms

It itself does not cause symptoms directly; symptoms arise from imbalances in androgen or estrogen production associated with abnormal levels. According to the document, elevated androstenedione levels are associated with increased adrenal or gonadal androgen production.

Common symptoms linked with elevated androstenedione include:

1. Hirsutism in females
2. Acne
3. Virilization
4. Menstrual irregularities
5. Amenorrhea
6. Infertility
7. Early pubertal changes or precocious puberty

In males, abnormal androstenedione levels may be associated with:

1. Gynecomastia
2. Fatigue
3. Androgen–estrogen imbalance

In children, excess levels may lead to premature adrenarche or abnormal pubertal development. Low androstenedione levels may be associated with adrenal or gonadal insufficiency, although symptoms depend on the underlying condition rather than the hormone alone.

Causes

Abnormal androstenedione levels occur due to alterations in adrenal or gonadal function, as outlined in the document.

Causes of elevated androstenedione include:

1. Polycystic ovarian syndrome (PCOS)
2. Congenital adrenal hyperplasia (CAH)
3. Androgen-secreting adrenal tumors
4. Androgen-secreting ovarian tumors
5. Exogenous intake of androstenedione or related supplements

The document notes that mildly elevated levels in adults are often idiopathic or associated with PCOS. However, levels equal to or exceeding 500 ng/dL may suggest the presence of an androgen-secreting tumor.

Causes of low androstenedione include:

1. Partial or complete adrenal failure
2. Gonadal failure
3. Physiological states affecting steroid production

Because it is secreted by both adrenal and gonadal sources, its measurement alone does not always identify the exact source of androgen excess.

Risk Factors

Risk factors for abnormal levels are linked to endocrine and reproductive disorders.

Major risk factors include:

1. Women with symptoms of hyperandrogenism
2. Individuals suspected of having PCOS
3. Children with signs of precocious puberty
4. Patients with suspected congenital adrenal hyperplasia
5. Individuals with adrenal or ovarian tumors
6. Men and women using androstenedione or DHEA supplements
7. Patients undergoing evaluation for infertility
8. Individuals with unexplained virilization or menstrual irregularities

The document also highlights that its levels vary by age, sex, pubertal stage, and physiological state, making interpretation dependent on appropriate reference ranges.

Prevention

The production is a normal physiological process and cannot be prevented entirely. However, the document outlines measures that help prevent misinterpretation, complications, and unnecessary exposure.

Preventive considerations include:

1. Early evaluation of symptoms related to androgen excess or deficiency
2. Avoiding unsupervised use of androstenedione-containing supplements
3. Monitoring hormone levels during and after treatment of endocrine disorders
4. Using androstenedione testing as part of a broader hormonal assessment

For accurate laboratory evaluation, the document emphasizes:

1. No special preparation required before testing
2. Collection of 3.0 mL blood in a plain red-capped tube
3. Early separation of serum and prompt transport to the laboratory
4. Awareness of test limitations, as androstenedione alone cannot determine the source of androgen excess
5. Correlation of results with clinical findings and other hormone tests

Regular monitoring and proper interpretation help guide diagnosis, treatment planning, and follow-up in disorders related to adrenal and gonadal steroid production.