Serum/plasma tests
Hormones
Steroid Hormones
Androstenedione
Bioavailable testosterone
Cortisol
DHEA-S
Dihydrotestosterone (DHT) (TOS)
Estradiol
Estradiol-HRT
17-OH progesterone (TOS)
Pregnenolone
Progesterone
Testosterone
Peptide Hormones
Follicle Stimulating Hormone (FSH)
Insulin (TOS)
Luteinizing Hormone (LH)
Secretin (TOS)
Sex Hormone Binding Globulin (SHBG)
Thyroid Stimulating Hormone (TSH)
Vasoactive Intestinal Polypeptide (VIP) (TOS)
Other Hormones
Free Triiodothyronine (FT3)
Free Thyroxine (FT4)
Triiodothyronine (T3)
Thyroxine (T4)
Other

TOS - To be offered shortly


Tests › Serum/plasma tests › Hormones › Steroid Hormones › Androstenedione

Androstenedione

Significance
Androstenedione is a weak androgen derived from DHEA and 17-hydroxy progesterone. It is synthesized in the adrenal glands and the gonads, and serves as an important precursor for synthesis of testosterone and Estradiol. It is under ACTH regulation, and secreted synchronously with Cortisol. Therefore, highest values occur early morning and lowest around midnight. In females, levels also vary with the menstrual cycle with higher levels at mid-cycle. Levels decline with age beginning at ages 25-30. Androstenedione is converted to Testosterone and Dihydrotestosterone in peripheral tissues (hair follicles, the sebaceous glands, the prostate and the external genitalia). In men, the contribution to testosterone levels from Androstenedione is minimal; whereas in women, it is substantial with regards to source for the total androgen production and the effects. Androstenedione is elevated in congenital adrenal hyperplasia with 21-hydroxylase deficiency, in 60% of hirsuite women, polycystic ovary syndrome, Cushing’s syndrome, and ectopic ACTH-producing tumors. Androstenedione determinations are primarily used for investigation of females presenting with hyperandrogenic symptoms (hirsuitism, acne, virilization) and for monitoring/managing antiandrogenic treatment.

Analysis
Determination of Androstenedione is performed by enzyme immunoassay.

Patient Preparation
Morning specimen is preferred. Avoid medication that can alter levels (at least 48 hrs prior to specimen collection) if possible or appropriate.

Specimen requirements
Serum specimen - from a plain redtop or a redtop gel (tiger top) tube. Separate serum from cells after centrifugation, if a plain redtop tube is used. Minimum volume required is 1 mL. Specimen should be kept refrigerated where possible.

Shipping Instructions
Ship specimen at ambient temperatures.

Additional information