Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Androstenedione, the precursor of testosterone is an androgenic (C19) steroid secreted by the adrenal cortex, the ovary and the testes. It binds very weakly to sex hormone binding globulin (SHBG) and likewise with low affinity to albumin. Androstenedione and testosterone are interconvertible; in the female around 60% of plasma testosterone is derived from peripheral conversion of androstenedione. In the testes, ovaries and adrenals, androstenedione and testosterone are precursors of the oestrogen (C18) steroids. Peripheral conversion of androgens to oestrogens may also occur.
Measurement of androstenedione may be useful in the investigation of hyperandrogenism. Elevated androstenedione concentrations can cause symptoms or signs of hyperandrogenism in women. Men with raised androstenedione may be asymptomatic, but through peripheral conversion of androgens to oestrogens can occasionally experience mild symptoms of oestrogen excess. Mild elevations in androstenedione may be idiopathic. However, pronounced elevations of androstenedione may be indicative of androgen-producing adrenal or gonadal tumours. In children, adrenal and gonadal tumours are uncommon, but many forms of congenital adrenal hyperplasia can lead to increased serum androstenedione concentrations. Diagnosis always requires measurement of other androgen precursors in addition to androstenedione.
Specimen container paediatric:
Serum
Specimen container adult:
Serum
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
1 mL blood
Sample stability:
Unseparated: Same day Separated: 5 days at 4-8°C, 1 year at -20°C (avoid storing in gel tubes)
Transport requirements:
Ambient temperature
Availability:
Assayed weekly
Site of analysis: RVI
Interpretation:
Elevated androstenedione concentrations indicate increased adrenal or gonadal androgen production. Mild elevations in adults may be idiopathic, or related to conditions such as polycystic ovarian syndrome (PCOS) in women. However, higher concentrations can suggest the presence of an androgen-secreting adrenal, or less commonly, gonadal tumour. Androstenedione levels are elevated in many patients with benign androgen-producing adrenal tumours. Most androgen-secreting adrenal carcinomas also exhibit elevated androstenedione levels and often elevations in 17-alpha-hydroxyprogesterone (17OHP) and dehydroepiandrosterone sulfate (DHEA-S). Most androgen-secreting gonadal tumours produce androstenedione as well as testosterone.
Diagnosis and differential diagnosis of congenital adrenal hyperplasia (CAH) always requires the measurement of several steroids. Patients with CAH due to 21-hydroxylase deficiency usually have very high serum concentrations of androstenedione. 17OHP concentrations are usually even higher. In the much less common 11-beta-hydroxylase deficiency, androstenedione levels are elevated but 17OHP is usually only mildly, if at all, elevated. Androstenendione may be measured alongside 17OHP and testosterone to monitor the treatment of CAH, where normalisation of androgen concentrations is a goal.
Reference ranges:
Androstenedione LC-MS/MS Reference Ranges (nmol/L):
| Age | Male | Female |
|---|---|---|
| <1yr | <2.5 | <2.5 |
| 1 to 4 | <0.7 | <0.7 |
| 5 to 9 | <1.4 | <1.7 |
| 10 to 14 | <3.7 | <6.0 |
| 15 to 39 | 1.4 to 6.2 | 1.3 to 7.4 |
| 40 to 59 | 1.4 to 6.2 | 0.9 to 5.7 |
| 60+ | 0.9 to 4.8 | <3.6 |