test directorySearch Results
Click here to search again.
Test Name:
Sex Hormone Binding Globulin
- SBMF No:
30032 - Performance Lab Name:
Immunochemistry - Test Mnemonic:
SHBG- - ABN:
Not required - CPT Code:
84270 - LOINC Code:
13967-5 - Also Known As:
SHBG - Also See:
30033 Testosterone, Total, Free, Bioavailable, and SHBG - Spec Type:
Serum - Spec Container:
Gold top (SST) or red top (serum) tube - Pref Vol:
1.0 mL - Min Vol:
0.6 mL - Fasting:
No - Spec Collect:
Routine venipuncture - Spec Process:
Clot 30 minutes
Promptly centrifuge 15 minutes
Immediately transfer serum to separate plastic tube
Properly centrifuged gel barrier tube sample does not require transfer of serum to separate tube - Spec Store Transport:
Refrigerated - Spec Stability:
1 week refrigerated (2-8°C)
2 months frozen (-20°C) – Do not use frost-free units that undergo repeated freeze/thaw cycles - Methodology:
Chemiluminescent Immunoassay (CLIA) - Use:
As an aid in the differential diagnosis of hirsutism
Measurement of total testosterone and SHBG provide information of free testosterone and bioavailable testosterone in vivo - Clinical Significance:
SHBG is a glycoprotein, synthesized in the liver, which binds testosterone and 5-dihydro-testosterone with high affinity and estradiol with somewhat lower affinity. It has a single steroid hormone-binding site, a molecular mass of approximately 80,000 to 100,000 daltons, and consists of two subunits, roughly equal in size.
SHBG typically circulates at higher concentrations in women than in men, due to the higher ratio of estrogens to androgens in women. For the same reason, SHBG levels in late pregnancy or after estrogen administration may be especially elevated. Administration of androgens tends to be associated with decreased SHBG levels.
Testosterone circulates primarily protein-bound, principally to SHBG, but also to albumin and cortisol-binding globulin. Since variations in the carrier protein levels may affect the concentration of testosterone in circulation, SHBG levels are commonly measured as a supplement to total testosterone determinations. The free androgen index (FAI), calculated as the ratio of total testosterone to SHBG, has proved to be a useful indicator of abnormal androgen status in conditions such as hirsutism.
- Reference Range:
Males: 10-57 nmol/L
Females: 18-144 nmol/L - Day Run:
Mon, Wed, Fri - Time Run:
8:00 am - Time Reported:
5:00 pm - Test Type:
HORMONE
