Synonyms
1-Testosterone-binding Globulin
Special Instructions
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Expected Turnaround Time
Within 1 day
Specimen Requirements
Specimen
Within 1 day
Volume
1 mL
Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)
Container
Gel-barrier tube (preferred) or red-top tube
Collection
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Storage Instructions
Room temperature
Causes for Rejection
Citrate plasma specimen; EDTA plasma specimen; improper labeling
Test Details
Use
Levels of SHBG are under the positive control of estrogens and thyroid hormones, and are suppressed by androgens. These influences dynamically control the liver synthesis of this carrier protein. Decreased levels of SHBG are frequently seen in hirsutism, virilization, obese postmenopausal women, and in women with diffuse hair loss. Increased levels may be present in cases of hyperthyroidism, testicular feminization, cirrhosis, male hypogonadism, pregnancy, women using oral contraceptives, and prepubertal children.